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Sample records for actinium 235

  1. Neutron-Induced Fission of Actinium-227, Protactinium-231 and Neptunium-237: Mass Distribution

    Results of radiochemical studies on the mass distribution in the neutron-induced fission of actinium-227, protactinium-231 and neptunium-237 have been presented. This work has been carried out as part of a programme to determine the mass distribution in the fission of heavy elements as a function of Z and A. All irradiations have been carried out in the core of the swimming-pool type reactor APSARA with cadmium shielding wherever necessary. Relative yields of several fission product nuclides have been obtained by a method involving a comparison of the fission product activities from the respective targets with those formed from uranium-235 simultaneously irradiated. Thermal-neutron fission yields of uranium-235 have been assumed. These results indicate a predominantly asymmetric mass distribution in all the three cases, and also a distinct though small symmetric peak in the case of actinium-227. (author)

  2. ADJ 235 Tutorials / adj235dotcom

    munna9

    2015-01-01

    ADJ 235 Entire Course (UOP)   For more course tutorials visit www.adj235.com   ADJ 235 Week 1 Checkpoint Legalizing Morality ADJ 235 Week 1 DQ 1 and DQ 2 ADJ 235 Week 2 Checkpoint Interpretation of Ethical Systems ADJ 235 Week 2 Assignment Deontological Versus Teleological Ethical Systems ADJ 235 Week 3 Checkpoint Undercover Operations ADJ 235 Week 3 DQ 1 and DQ 2 ADJ 235 Week 4 Checkpoint Law Enforcement Code of Ethics ADJ 235 Week 4 ...

  3. Extraction of actinium with di-(2-ethylhexyl)phosphoric acid from hydrochloric and nitric acid solutions

    The extraction of actinium with HDEHP from Cl- and NO3- systems has been investigated. It was found that extraction of actinium from HCl solutions is much better than from HNO3 solutions. Stability constants of actinium complexes Ac(X-)+2 with Cl- and NO3- ligands were determined. Our results show that the actinium formed less stable complexes with Cl- than with NO3- ligands. 5 refs., 3 figs., 1 tab. (author)

  4. The sorption of polonium, actinium and protactinium onto geological materials

    This paper describes a combined experimental and modeling program of generic sorption studies to increase confidence in the performance assessment for a potential high-level radioactive waste repository in Japan. The sorption of polonium, actinium and protactinium onto geological materials has been investigated. Sorption of these radioelements onto bentonite, tuff and granodiorite from equilibrated de-ionized water was studied under reducing conditions at room temperature. In addition, the sorption of actinium and protactinium was investigated at 60 C. Thermodynamic chemical modeling was carried out to aid interpretation of the results

  5. Discovery of the actinium, thorium, protactinium, and uranium isotopes

    Fry, C; Thoennessen, M

    2012-01-01

    Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  6. Separation of Actinium 227 from the uranium minerals

    The purpose of this work was to separate Actinium 227, whose content is 18%, from the mineral carnotite found in Gomez Chihuahua mountain range in Mexico. The mineral before processing is is pre-concentrated and passed, first through anionic exchange resins, later the eluate obtained is passed through cationic resins. The resins were 20-50 MESH QOWEX and 100-200 MESH 50 X 8-20 in some cased 200-400 MESH AG 50W-X8, 1X8 in other cases. The eluates from the ionic exchange were electrodeposited on stainless steel polished disc cathode and platinum electrode as anode; under a current ODF 10mA for 2.5 to 5 hours and of 100mA for .5 of an hour. it was possible to identify the Actinium 227 by means of its descendents, TH-227 and RA-223, through alpha spectroscopy. Due to the radiochemical purity which the electro deposits were obtained the Actinium 227 was low and was not quantitatively determined. A large majority of the members of the natural radioactive series 3 were identified and even alpha energies reported in the literature with very low percentages of non-identified emissions were observed. We conclude that a more precise study is needed concerning ionic exchange and electrodeposit to obtain an Actinium 227 of radiochemical purity. (Author)

  7. Spectroscopic and computational investigation of actinium coordination chemistry.

    Ferrier, Maryline G; Batista, Enrique R; Berg, John M; Birnbaum, Eva R; Cross, Justin N; Engle, Jonathan W; La Pierre, Henry S; Kozimor, Stosh A; Lezama Pacheco, Juan S; Stein, Benjamin W; Stieber, S Chantal E; Wilson, Justin J

    2016-01-01

    Actinium-225 is a promising isotope for targeted-α therapy. Unfortunately, progress in developing chelators for medicinal applications has been hindered by a limited understanding of actinium chemistry. This knowledge gap is primarily associated with handling actinium, as it is highly radioactive and in short supply. Hence, Ac(III) reactivity is often inferred from the lanthanides and minor actinides (that is, Am, Cm), with limited success. Here we overcome these challenges and characterize actinium in HCl solutions using X-ray absorption spectroscopy and molecular dynamics density functional theory. The Ac-Cl and Ac-OH2O distances are measured to be 2.95(3) and 2.59(3) Å, respectively. The X-ray absorption spectroscopy comparisons between Ac(III) and Am(III) in HCl solutions indicate Ac(III) coordinates more inner-sphere Cl(1-) ligands (3.2±1.1) than Am(III) (0.8±0.3). These results imply diverse reactivity for the +3 actinides and highlight the unexpected and unique Ac(III) chemical behaviour. PMID:27531582

  8. Production of high-purity radium-223 from legacy actinium-beryllium neutron sources.

    Soderquist, Chuck Z; McNamara, Bruce K; Fisher, Darrell R

    2012-07-01

    Radium-223 is a short-lived alpha-particle-emitting radionuclide with potential applications in cancer treatment. Research to develop new radiopharmaceuticals employing (223)Ra has been hindered by poor availability due to the small quantities of parent actinium-227 available world-wide. The purpose of this study was to develop innovative and cost-effective methods to obtain high-purity (223)Ra from (227)Ac. We obtained (227)Ac from two surplus actinium-beryllium neutron generators. We retrieved the actinium/beryllium buttons from the sources and dissolved them in a sulfuric-nitric acid solution. A crude actinium solid was recovered from the solution by coprecipitation with thorium fluoride, leaving beryllium in solution. The crude actinium was purified to provide about 40 milligrams of actinium nitrate using anion exchange in methanol-water-nitric acid solution. The purified actinium was then used to generate high-purity (223)Ra. We extracted (223)Ra using anion exchange in a methanol-water-nitric acid solution. After the radium was separated, actinium and thorium were then eluted from the column and dried for interim storage. This single-pass separation produces high purity, carrier-free (223)Ra product, and does not disturb the (227)Ac/(227)Th equilibrium. A high purity, carrier-free (227)Th was also obtained from the actinium using a similar anion exchange in nitric acid. These methods enable efficient production of (223)Ra for research and new alpha-emitter radiopharmaceutical development. PMID:22697483

  9. ADJ 235 UOP Course Tutorial / adj235dotcom

    geenid

    2015-01-01

    ADJ 235 Entire Course (UOP) For more course tutorials visit www.adj235.com ADJ 235 Week 1 Checkpoint Legalizing Morality ADJ 235 Week 1 DQ 1 and DQ 2 ADJ 235 Week 2 Checkpoint Interpretation of Ethical Systems ADJ 235 Week 2 Assignment Deontological Versus Teleological Ethical Systems ADJ 235 Week 3 Checkpoint Undercover Operations ADJ 235 Week 3 DQ 1 and DQ 2 ADJ 235 Week 4 Checkpoint Law Enforcement Code of Ethics ADJ 235 Week 4 Assignment Law Enforce...

  10. ADJ 235 Courses Tutorial / indigohelp

    nesa

    2015-01-01

    ADJ 235 Week 1 Checkpoint Legalizing Morality ADJ 235 Week 1 DQ 1 and DQ 2 ADJ 235 Week 2 Checkpoint Interpretation of Ethical Systems ADJ 235 Week 2 Assignment Deontological Versus Teleological Ethical Systems ADJ 235 Week 3 Checkpoint Undercover Operations ADJ 235 Week 3 DQ 1 and DQ 2 ADJ 235 Week 4 Checkpoint Law Enforcement Code of Ethics ADJ 235 Week 4 Assignment Law Enforcement Deviance ADJ 235 Week 5 Checkpoint Attorneys Ethical Responsibilities ADJ ...

  11. Radium, thorium, and actinium extraction from seawater using an improved manganese-oxide-coated fiber

    Laboratory experiments were conducted to determine the efficiency with which improved manganese-oxide-coated acrylic fibers extract radium, thorium, and actinium from seawater. Tests were made using surface seawater spiked with 227Ac, 227Th and 223Ra. For sample volumes of approximately 30 liters and flow rates up to 0.5 liters per minute, radium and actinium are removed quantitatively. Approximately 80-95% of the thorium is removed under these same conditions. (Auth.)

  12. 31 CFR 540.315 - Uranium-235 (U235).

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium-235 (U235). 540.315 Section... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.315 Uranium-235 (U235). The term uranium-235 or U235 means the...

  13. BUS 235 Course tutorial/ indigohelp

    SFVD

    2015-01-01

    For more classes visit www.indigohelp.com   BUS 235 Week 1 DQ 1 Marketing Trends BUS 235 Week 1 DQ 2 Customer Needs and Wants BUS 235 Week 2 DQ 1 Market Research BUS 235 Week 2 DQ 2 Customer Loyalty BUS 235 Week 3 DQ 1 Branding Debate BUS 235 Week 3 DQ 2 New Product Development BUS 235 Week 3 Assignment Retail Store (Walmart) BUS 235 Week 4 DQ 1 Price and Ethics BUS 235 Week 4 DQ 2 Service Marketing BUS 235 Week 5 DQ 1 Super Bowl Advertisin...

  14. ADJ 235 Courses/snaptutorial

    charles

    2015-01-01

    ­For more classes visits www.indigohelp.com                 ADJ 235 Week 1 Checkpoint Legalizing Morality ADJ 235 Week 1 DQ 1 and DQ 2 ADJ 235 Week 2 Checkpoint Interpretation of Ethical Systems ADJ 235 Week 2 Assignment Deontological Versus Teleological Ethical Systems ADJ 235 Week 3 Checkpoint Undercover Operations ADJ 235 Week 3 DQ 1 and DQ 2 ADJ 235 Week 4 Checkpoint Law Enforcement...

  15. Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

    Harvey, James T.; Nolen, Jerry; Vandergrift, George; Gomes, Itacil; Kroc, Tom; Horwitz, Phil; McAlister, Dan; Bowers, Del; Sullivan, Vivian; Greene, John

    2011-12-30

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces {approx}100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 Ge

  16. Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces ∼100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 GeV protons

  17. Comment: 235 [Taxonomy Icon

    Full Text Available koji mold Aspergillus oryzae Aspergillus_oryzae_L.png 235.png Osamu Mizutani (Tohoku University ... ing)) licensed under CC Attribution2.1 Japan 撮影: 水 谷治(東北大学(現 酒類総研)) Photo: Osamu Mizutani ...

  18. ADJ 235 UOP COURSE Tutorial/UOPHELP

    vasu

    2015-01-01

    ADJ 235 Week 1 Checkpoint Legalizing Morality ADJ 235 Week 1 DQ 1 and DQ 2 ADJ 235 Week 2 Checkpoint Interpretation of Ethical Systems ADJ 235 Week 2 Assignment Deontological Versus Teleological Ethical Systems ADJ 235 Week 3 Checkpoint Undercover Operations ADJ 235 Week 3 DQ 1 and DQ 2 ADJ 235 Week 4 Checkpoint Law Enforcement Code of Ethics ADJ 235 Week 4 Assignment Law Enforcement Deviance ADJ 235 Week 5 Checkpoint Attorneys Ethical Responsibilities ADJ ...

  19. A new method for the determination of low-level actinium-227 in geological samples

    We developed a new method for the determination of 227Ac in geological samples. The method uses extraction chromatographic techniques and alpha-spectrometry and is applicable for a range of natural matrices. Here we report on the procedure and results of the analysis of water (fresh and seawater) and rock samples. Water samples were acidified and rock samples underwent total dissolution via acid leaching. A DGA (N,N,N',N'-tetra-n-octyldiglycolamide) extraction chromatographic column was used for the separation of actinium. The actinium fraction was prepared for alpha spectrometric measurement via cerium fluoride micro-precipitation. Recoveries of actinium in water samples were 80 ± 8 % (number of analyses n = 14) and in rock samples 70 ± 12 % (n = 30). The minimum detectable activities (MDA) were 0.017-0.5 Bq kg-1 for both matrices. Rock sample 227Ac activities ranged from 0.17 to 8.3 Bq kg-1 and water sample activities ranged from below MDA values to 14 Bq kg-1of 227Ac. From the analysis of several standard rock and water samples with the method we found very good agreement between our results and certified values. (author)

  20. Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

    Momeni, M.H.

    1981-09-01

    This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore.

  1. Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

    This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore

  2. 32 CFR 235.5 - Responsibilities.

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Responsibilities. 235.5 Section 235.5 National... SALE OR RENTAL OF SEXUALLY EXPLICIT MATERIAL ON DOD PROPERTY § 235.5 Responsibilities. (a) The... its responsibilities as set forth in § 235.6. (b) The Secretaries of the Military Departments...

  3. In-source laser spectroscopy developments at TRILIS—towards spectroscopy on actinium and scandium

    Resonance Ionization Laser Ion Sources (RILIS) have become a versatile tool for production and study of exotic nuclides at Isotope Separator On-Line (ISOL) facilities such as ISAC at TRIUMF. The recent development and addition of a grating tuned spectroscopy laser to the TRIUMF RILIS solid state laser system allows for wide range spectral scans to investigate atomic structures on short lived isotopes, e.g., those from the element actinium, produced in uranium targets at ISAC. In addition, development of new and improved laser ionization schemes for rare isotope production at ISAC is ongoing. Here spectroscopic studies on bound states, Rydberg states and autoionizing (AI) resonances on scandium using the existing off-line capabilities are reported. These results allowed to identify a suitable ionization scheme for scandium via excitation into an autoionizing state at 58,104 cm − 1 which has subsequently been used for ionization of on-line produced exotic scandium isotopes.

  4. 32 CFR 235.7 - Information requirements.

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Information requirements. 235.7 Section 235.7 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS SALE OR RENTAL OF SEXUALLY EXPLICIT MATERIAL ON DOD PROPERTY § 235.7 Information requirements....

  5. 45 CFR 235.110 - Fraud.

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Fraud. 235.110 Section 235.110 Public Welfare... PROGRAMS § 235.110 Fraud. State plan requirements: A State plan under title I, IV-A, X, XIV, or XVI of the... criteria for identifying situations in which a question of fraud in the program may exist, and...

  6. 7 CFR 905.235 - Assessment rate.

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 905.235 Section 905.235 Agriculture... TANGELOS GROWN IN FLORIDA Assessment Rates § 905.235 Assessment rate. On and after August 1, 2007, an assessment rate of $0.0072 per 4/5 bushel carton or equivalent is established for Florida citrus...

  7. 7 CFR 915.235 - Assessment rate.

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 915.235 Section 915.235 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 915.235 Assessment rate. On and after April 1, 2005, an assessment rate of $0.27 per...

  8. 7 CFR 906.235 - Assessment rate.

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 906.235 Section 906.235 Agriculture... RIO GRANDE VALLEY IN TEXAS Rules and Regulations § 906.235 Assessment rate. On and after August 1, 2004, an assessment rate of $0.12 per 7/10-bushel carton or equivalent is established for oranges...

  9. 49 CFR 235.9 - Civil penalty.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Civil penalty. 235.9 Section 235.9 Transportation... SIGNAL SYSTEM OR RELIEF FROM THE REQUIREMENTS OF PART 236 § 235.9 Civil penalty. Any person (an entity of... violates any requirement of this part or causes the violation of any such requirement is subject to a...

  10. 7 CFR 235.3 - Administration.

    2010-01-01

    ... programs in accordance with the applicable requirements of this part, 7 CFR parts 210, 215, 220, 225, 226... 7 Agriculture 4 2010-01-01 2010-01-01 false Administration. 235.3 Section 235.3 Agriculture... CHILD NUTRITION PROGRAMS STATE ADMINISTRATIVE EXPENSE FUNDS § 235.3 Administration. (a) Within...

  11. 49 CFR 235.20 - Protests.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Protests. 235.20 Section 235.20 Transportation... SIGNAL SYSTEM OR RELIEF FROM THE REQUIREMENTS OF PART 236 § 235.20 Protests. (a) A protest against the... concise statement of the interest of protestant in the proceeding. (b) Protests shall be filed with...

  12. origin of elements of the Uranium-235 family observed in the Ellez river near the EL-4 experimental nuclear reactor in dismantling (Monts d'Arree- Finistere department)

    In a previous study which concerned the catchment basin of the harbour of Brest, the A.C.R.O. put in evidence a marking by artificial radioelements around the power plant of Brennilis which can be imputed without ambiguities to the nuclear installation. It also put in evidence abnormalities concerning the natural radioactivity which justifies this new study. In the area of the Monts d'Arree, actinium 227 (227Ac), non born by its ascendents which are 235U and 231Pa is observed. This phenomenon is characterized by mass activities superior to these ones of 235U and able to reach these ones of 238U. Its presence corresponds with the drainage of the Ellez river since the former channel of radioactive effluents releases from the nuclear power plant EL-4 up to the reservoir Saint-Herblot situated 6 km downstream. The strongest values of radioactivity are registered near the disused power plant, at this place a relationship exists between the level of actinium 227 and this one of the artificial radioactivity as it exists a relationship with the decay products of radon exhaled from the subsoil (210Pb). But its presence is not limited to a part of the Ellez river, it is equally observed in terrestrial medium, in places in priori not influenced by the direct liquid effluents of the power plant. This place is situated at more than 4 km and without any connection with the Ellez waters. At this stage of the study, it is not possible to answer with certainty the question of the origin of this phenomenon. A new reorientation is considered indispensable to clarify definitively the origin of this unknown phenomenon in the scientific publications and the environmental monitoring. (N.C.)

  13. Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

    Raeder, S.; Bastin, B.; Block, M.; Creemers, P.; Delahaye, P.; Ferrer, R.; Fléchard, X.; Franchoo, S.; Ghys, L.; Gaffney, L. P.; Granados, C.; Heinke, R.; Hijazi, L.; Huyse, M.; Kron, T.; Kudryavtsev, Yu.; Laatiaoui, M.; Lecesne, N.; Luton, F.; Moore, I. D.; Martinez, Y.; Mogilevskiy, E.; Naubereit, P.; Piot, J.; Rothe, S.; Savajols, H.; Sels, S.; Sonnenschein, V.; Traykov, E.; Van Beveren, C.; Van den Bergh, P.; Van Duppen, P.; Wendt, K.; Zadvornaya, A.

    2016-06-01

    To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (IGLIS) technique in the supersonic gas jet produced by a de Laval nozzle installed at the exit of the stopping gas cell. Carrying out laser ionization in the low-temperature and low density supersonic gas jet eliminates pressure broadening, which will significantly improve the spectral resolution. This article presents the required modifications at the Leuven Isotope Separator On-Line (LISOL) facility that are needed for the first on-line studies of in-gas-jet laser spectroscopy. Different geometries for the gas outlet and extraction ion guides have been tested for their performance regarding the acceptance of laser ionized species as well as for their differential pumping capacities. The specifications and performance of the temporarily installed high repetition rate laser system, including a narrow bandwidth injection-locked Ti:sapphire laser, are discussed and first preliminary results on neutron-deficient actinium isotopes are presented indicating the high capability of this novel technique.

  14. ADJ 235 uop course tutorial/uop help

    andor

    2015-01-01

     For more course tutorials visit www.uophelp.com     ADJ 235 Week 1 Checkpoint Legalizing Morality ADJ 235 Week 1 DQ 1 and DQ 2 ADJ 235 Week 2 Checkpoint Interpretation of Ethical Systems ADJ 235 Week 2 Assignment Deontological Versus Teleological Ethical Systems ADJ 235 Week 3 Checkpoint Undercover Operations ADJ 235 Week 3 DQ 1 and DQ 2 ADJ 235 Week 4 Checkpoint Law Enforcement Code of Ethics ADJ 235 Week 4 Assignment Law Enforcemen...

  15. Recommended decay data for 235-neptunium

    An evaluation has been made of the decay of 235Np, a nuclide that has become popular for monitoring neptunium chemistry in the environment. Compared with other radioactive nuclides, 235Np produces few emissions that are suitable for quantitative analysis. A semi-theoretical study was undertaken, and it is recommended that four K-shell X rays are used to monitor 235Np. (U.K.)

  16. Dicty_cDB: SLA235 [Dicty_cDB

    Full Text Available SL (Link to library) SLA235 (Link to dictyBase) - - - Contig-U16325-1 SLA235E (Link... to Original site) - - - - - - SLA235E 470 Show SLA235 Library SL (Link to library) Clone ID SLA235 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/SL/SLA2-B/SLA235Q.Seq.d/ Representative seq. ID SLA23...5E (Link to Original site) Representative DNA sequence >SLA235 (SLA235Q) /CSM/SL/SLA2-B/SLA235Q.Seq.d/ CCAAA...GTTTTTAAAAAAAAAA AAAAAAATAATTATTAAATTTTTAAAATTATAAATAATAATCTTCTTATG sequence update 1997. 5. 7 Transla

  17. 14 CFR 21.235 - Application.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Application. 21.235 Section 21.235 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION... Administrator, to the Aircraft Certification Office for the area in which the manufacturer is located. (b)...

  18. 50 CFR 600.235 - Financial disclosure.

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS Council Membership § 600.235 Financial... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Financial disclosure. 600.235 Section 600.... Financial interest in harvesting, processing, or marketing (1) includes: (i) Stock, equity, or...

  19. 33 CFR 105.235 - Communications.

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Communications. 105.235 Section... MARITIME SECURITY: FACILITIES Facility Security Requirements § 105.235 Communications. (a) The Facility... conditions at the facility. (b) Communication systems and procedures must allow effective and...

  20. 44 CFR 19.235 - Statutory amendments.

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Statutory amendments. 19.235 Section 19.235 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF... of factors related to the individual's personal appearance, poise, and talent. The pageant,...

  1. 24 CFR 235.206 - Substitute mortgagors.

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Substitute mortgagors. 235.206... MORTGAGE INSURANCE AND ASSISTANCE PAYMENTS FOR HOME OWNERSHIP AND PROJECT REHABILITATION Contract Rights and Obligations-Homes for Lower Income Families § 235.206 Substitute mortgagors. (a) Selling...

  2. 32 CFR 235.1 - Purpose.

    2010-07-01

    ... OF SEXUALLY EXPLICIT MATERIAL ON DOD PROPERTY § 235.1 Purpose. This part implements 10 U.S.C. 2489a... sexually explicit materials on property under the jurisdiction of the Department of Defense or by...

  3. 49 CFR 235.3 - Application.

    2010-10-01

    ... SIGNAL SYSTEM OR RELIEF FROM THE REQUIREMENTS OF PART 236 § 235.3 Application. (a) Except as provided in... part of the general railroad system of transportation. (b) This part does not apply to rail...

  4. Origin of elements of the Uranium-235 family observed in the Ellez river near the EL-4 experimental nuclear reactor in dismantling (Monts d'Arree- Finistere department); Origine des elements de la famille de l'uranium-235 observes dans la riviere Ellez a proximite du reacteur nucleaire experimental EL4 en cours de demantelement (Mont d'Arree - departement du Finistere). Resultats et premiers constats annee 2006

    NONE

    2006-07-01

    In a previous study which concerned the catchment basin of the harbour of Brest, the A.C.R.O. put in evidence a marking by artificial radioelements around the power plant of Brennilis which can be imputed without ambiguities to the nuclear installation. It also put in evidence abnormalities concerning the natural radioactivity which justifies this new study. In the area of the Monts d'Arree, actinium 227 ({sup 227}Ac), non born by its ascendents which are {sup 235}U and {sup 231}Pa is observed. This phenomenon is characterized by mass activities superior to these ones of {sup 235}U and able to reach these ones of {sup 238}U. Its presence corresponds with the drainage of the Ellez river since the former channel of radioactive effluents releases from the nuclear power plant EL-4 up to the reservoir Saint-Herblot situated 6 km downstream. The strongest values of radioactivity are registered near the disused power plant, at this place a relationship exists between the level of actinium 227 and this one of the artificial radioactivity as it exists a relationship with the decay products of radon exhaled from the subsoil ({sup 210}Pb). But its presence is not limited to a part of the Ellez river, it is equally observed in terrestrial medium, in places in priori not influenced by the direct liquid effluents of the power plant. This place is situated at more than 4 km and without any connection with the Ellez waters. At this stage of the study, it is not possible to answer with certainty the question of the origin of this phenomenon. A new reorientation is considered indispensable to clarify definitively the origin of this unknown phenomenon in the scientific publications and the environmental monitoring. (N.C.)

  5. Dicty_cDB: SSC235 [Dicty_cDB

    Full Text Available SS (Link to library) SSC235 (Link to dictyBase) - - - Contig-U16581-1 SSC235F (Link to Original site) SS...C235F 463 - - - - - - Show SSC235 Library SS (Link to library) Clone ID SSC235 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/SS/SSC2-B/SSC235Q.Seq.d/ Representative seq. ID SSC23...5F (Link to Original site) Representative DNA sequence >SSC235 (SSC235Q) /CSM/SS/SSC2-B/SSC235Q.Seq.d/ ANTAA...pdate 1998. 8. 5 Translated Amino Acid sequence xk*kkkkkk*kki**vlkwysfnkkkkkttiisskkkiknkkkknkkk***aipwdleki

  6. 24 CFR 235.1234 - Term of assistance payment contract in connection with mortgages insured under section 235(r) of...

    2010-04-01

    ... certified by the mortgagee and shall continue until the contract is terminated pursuant to 24 CFR 235.375... pursuant to 24 CFR 235.375. The mortgagor will acknowledge receipt of a notice containing the expiration... in connection with mortgages insured under section 235(r) of the Act. 235.1234 Section...

  7. Decay scheme of the U235

    A study of the Th231 excited levels from the alpha decay of the U235, is carried out. The alpha particle spectrum was measured by means of a semiconductor counter spectrometer with an effective resolution of 18 keV. Nineteen new lines were identified. The gamma-ray spectrum was measured with thin samples of U235, free from decay products, and in such geometrical conditions, that most of the interference effects were eliminated. The gamma-gamma coincidence spectra have made easier a better knowledge of the transition between the several levels. (Author) 110 refs

  8. 46 CFR 108.235 - Construction.

    2010-10-01

    ... limit drop test in 14 CFR 29.725, or a load of not less than 75 percent of the helicopter maximum weight... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Helicopter Facilities § 108.235 Construction. (a) Each helicopter deck must...

  9. 32 CFR 235.6 - Procedures.

    2010-07-01

    ... OF SEXUALLY EXPLICIT MATERIAL ON DOD PROPERTY § 235.6 Procedures. (a) The Board shall periodically... determine whether any such material is sexually explicit in accordance with this part. (b) If the Board... jurisdiction may be sexually explicit as defined herein, and such material is not addressed by the...

  10. 32 CFR 235.4 - Policy.

    2010-07-01

    ... OF SEXUALLY EXPLICIT MATERIAL ON DOD PROPERTY § 235.4 Policy. It is DoD policy that: (a) No sexually explicit material may be offered for sale or rental on property under the DoD jurisdiction, and no member..., shall offer for sale or rental any sexually explicit material. (b) Material shall not be deemed...

  11. 32 CFR 235.3 - Definitions.

    2010-07-01

    ... SALE OR RENTAL OF SEXUALLY EXPLICIT MATERIAL ON DOD PROPERTY § 235.3 Definitions. For the purpose of this part, the following definitions apply: Dominant theme. A theme of any material that is superior in... Exchanges, and ship stores. Sexually explicit material. Material, the dominant theme of which is...

  12. The Coriolis attenuation problem in 235U

    A new version of the particle-rotor model, featuring diagonalization of a state-dependent pairing force and the full recoil term, has been applied to 235U. A significant improvement is obtained in the description of the Coriolis coupled K=5/2, 7/2 and 9/2 rotational bands. No ad hoc Coriolis attenuation factors are used. (orig.)

  13. 21 CFR 514.235 - Judicial review.

    2010-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS NEW ANIMAL DRUG APPLICATIONS Judicial Review § 514.235 Judicial review. (a... manufacturer or distributor of an identical, related, or similar drug product, as defined in § 310.6 of...

  14. Indirect NMR detection of 235U in gaseous uranium hexafluoride

    Ursu, I.; Demco, D.E.; Bogdan, M.; Fitori, P.; Darabont, A.

    1985-01-01

    The possibility to use nuclear magnetic resonance in indirect detection of the 235U nucleus in gaseous UF6 is discussed. The 19F absorption spectra linewidths in gaseous UF6 was investigated as a function of 235U enrichment, revealing a dependence on the isotope concentration. The 19F-235U indirect scalar coupling modulated by 235U quadrupole relaxation is the relaxation mechanism responsible for this enrichment effect.

  15. Photonuclear data evaluation of U235

    This report presents cross-sections calculation up to 130 MeV for U235. The photoabsorption process is described by the giant dipole resonance and quasi deuteron mechanisms. Neutron emission is treated within the preequilibrium and statistical models while fission is also calculated within this statistical approach using a double-humped fission barrier. The U235(γ,n), (γ,2n) and (γ,f) cross-sections are calculated with the TALYS-0.64 code using a coupled channels optical potential. Charges in level densities did not affect results significantly. Fission barrier heights and widths were modified to reproduce experimental data. Neither fission level densities nor other default fission parameters were changed. More calculations are needed in order to check cross-sections sensitivity to other level densities and fission models. (A.C.)

  16. 32 CFR 235.2 - Applicability and scope.

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Applicability and scope. 235.2 Section 235.2 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS SALE OR RENTAL OF SEXUALLY EXPLICIT MATERIAL ON DOD PROPERTY § 235.2 Applicability and scope....

  17. Physical conditions in star forming regions around S235

    Kirsanova, Maria S; Sobolev, Andrej M; Henkel, Christian; Tsivilev, Alexander P

    2013-01-01

    Gas density and temperature in star forming regions around Sh2-235 are derived from ammonia line observations. This information is used to evaluate formation scenarios and to determine evolutionary stages of the young embedded clusters S235 East1, S235 East2, and S235 Central. We also estimate the gas mass in the embedded clusters and its ratio to the stellar mass. S235 East1 appears to be less evolved than S235 East2 and S235 Central. In S235 East1 the molecular gas mass exceeds that in the other clusters. Also, this cluster is more embedded in the parent gas cloud than the other two. Comparison with a theoretical model shows that the formation of these three clusters could have been stimulated by the expansion of the Sh2-235 HII region (hereafter S235) via a collect-and-collapse process, provided the density in the surrounding gas exceeds $3\\cdot10^3$ cm$^{-3}$, or via collapse of pre-existing clumps. The expansion of S235 cannot be responsible for star formation in the southern S235 A-B region. However, fo...

  18. 8 CFR 235.6 - Referral to immigration judge.

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Referral to immigration judge. 235.6 Section 235.6 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS INSPECTION OF PERSONS APPLYING FOR ADMISSION § 235.6 Referral to immigration judge. (a) Notice—(1) Referral by Form...

  19. 49 CFR 192.235 - Preparation for welding.

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Preparation for welding. 192.235 Section 192.235... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192.235 Preparation for welding. Before beginning any welding, the welding surfaces must be clean and free of any material...

  20. 49 CFR 234.235 - Insulated rail joints.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Insulated rail joints. 234.235 Section 234.235..., DEPARTMENT OF TRANSPORTATION GRADE CROSSING SIGNAL SYSTEM SAFETY AND STATE ACTION PLANS Maintenance, Inspection, and Testing Maintenance Standards § 234.235 Insulated rail joints. Each insulated rail joint...

  1. Centrifuge for separation of enriched 235U

    The invention claim is for a centrifuge for enrichment of 235U characterized by: (1) a rotor provided with hollow upper and lower rotating shafts which serve, respectively, as a feed conduit for a light inert-gas/UF6-gas mixture and as a discharge conduit for the light inert gas, and provided with top and bottom end-plates having vents for discharging the 235U-enriched gas and 235U-depleted gas in equal amounts; (2) a fixed outer jacket which accomodates the freely rotating rotor in such a manner as to form annular slits between the shoulders of the rotor and the inner wall of the jacket, and is equipped at the mid-section with gas-inlet conduits for injecting the inert light gas into the annular space between the rotor and the jacket through the openings provided at the tips of the conduits in the direction of the rotor's rotation and also tangentially to the rotor, and is further equipped near the top and bottom with gas-outlet conduits fitted with control valves; and (3) heating and cooling units installed at the top and bottom of the annualr space between the rotor and the jacket. (U.S.)

  2. International 235U fission foil mass intercomparison

    In the measurement of neutron fission cross sections, one of the larger uncertainties is associated with the mass determination of the fissionable deposit. Inconsistencies in determinations of the fission cross sections may be a result of systematic errors associated with the measurement of the deposit mass. As part of a study to check the consistency of mass scales at a number of laboratories throughout the world, two 235U deposits from the Khlopin Radium Institute (KRI) in Leningrad, USSR, were made available through the assistance of the International Atomic Energy Agency for measurements at the National Bureau of Standards (NBS) and Argonne National Laboratory (ANL). These deposits are directly traceable to foils used in very precise measurements of the 235U(n,f) cross section made in a collaborative effort by KRI and the Technical University of Dresden (TUD), GDR. The study undertaken at the NBS consisted of two parts. One part was the measurement of the alpha-decay rates of the two 235U samples (KRI VI and KRI-XV) with a low-geometry-counting spectrometry facility. The other was the measurement of the total alpha disintegration rate of the samples employing a 2II alpha counter

  3. Practical Gamma Counting of Unirradiated Uranium-235

    During the fabrication of reactor fuel elements it is necessary to have assurance regarding the accuracy of the fabricator's uranium assignment within the specified tolerances. Destructive analysis of random samples is both expensive and time-consuming. Where the uranium-bearing components are suitable for gamma counting, a non-destructive method of assay can be used with greater efficiency and equal accuracy. The particular method described was used for checking fuel cores of nominal 30 wt.% enriched uranium in aluminium measuring about two inches square by 0.080 in. and 0.160 in. thick. The equipment was a basic Nal scintillation counter equipped with a single-channel analyser. The analyser, however, was operated with a very wide window covering both the 90-keV and 184-keV peaks characteristic of uranium-235. In practice, the threshold level acid the window opening, were adjusted to give the optimum maximum count rate as indicated by a ratemeter. The counting of a fuel core was then performed with the Nal crystal essentially unshielded and located several inches above the fuel core. The counting time was adjusted to yield a total count in the range of 105 to 106 in order to minimize the counting error. Effects due to variations in the counting geometry and to non-uniform uranium distribution were minimized by the relatively large separation of the crystal from the fuel core. Effects due to shifting of analyser window were minimized by use of a wide opening. To compensate for possible non-uniform uranium distribution through the thickness of a fuel core, each core was counted on both sides. The total count obtained in this manner was directly proportioned to the uranium-235 content of the fuel core. In application, the counting equipment was set up in the fabricator's plant and a number of production fuel cores were counted. The plotting of the total counts against the fabricator's uranium-235 assignment revealed an unexpected error in the fabricator's system

  4. Groundwater seepage from the Ranger uranium mine tailings dam: radioisotopes of radium, thorium and actinium. Supervising Scientist report 106

    Monitoring of bores near the Ranger uranium mine tailings dam has revealed deterioration in water quality in several bores since 1983. In a group of bores to the north of the dam, increases have been observed of up to 500 times for sulphate concentrations and of up to 5 times for 226Ra concentrations. Results are presented here of measurements of members of the uranium, thorium and actinium decay series in borewater samples collected between 1985 and 1993. In particular, measurements of all four naturally-occurring radium isotopes have been used in an investigation of the mechanism of radium concentration changes. For the most seepage-affected bores the major findings of the study include: 228Ra/226Ra 223Ra /226Ra and 224Ra/228Ra ratios all increased over the course of the study; barium concentrations show high seasonal variability, being lower in November than May, but strontium concentrations show a steady increase with time. Calculations show that the groundwater is probably saturated with respect to barite but not with respect to celestite or anglesite; sulphide concentrations are low in comparison with sulphate, and are higher in November than in May; and 227Ac concentrations have increased with time, but do not account for the high 223Ra/226Ra ratios. It is concluded on the basis of these observations that increases in Ra isotope concentrations observed in a number of seepage-affected bores arise from increases in salinity leading to desorption of radium from adsorption sites in the vicinity of the bore rather by direct transport of radium from the tailings. Increased salinity is also causing the observed increases in 227Ac and strontium concentrations, while formation of a barite solid phase in the groundwater is causing the removal of some radium from solution. This is the cause of the increasing radium isotope ratios noted above

  5. Decay scheme of the U{sup 2}35; Esquema de desintegracion del U-235

    Gaeta, R.

    1965-07-01

    A study of the Th{sup 2}31 excited levels from the alpha decay of the U{sup 2}35, is carried out. The alpha particle spectrum was measured by means of a semiconductor counter spectrometer with an effective resolution of 18 keV. Nineteen new lines were identified. The gamma-ray spectrum was measured with thin samples of U{sup 2}35, free from decay products, and in such geometrical conditions, that most of the interference effects were eliminated. The gamma-gamma coincidence spectra have made easier a better knowledge of the transition between the several levels. (Author) 110 refs.

  6. Preparation of 235U target by electrodeposition

    A target for the production of fission 99Mo in a nuclear reactor is composed of an enclosed, cylindrical vessel. Preferable vessel is comprised of stainless steel, having a thin, continuous, uniform layer of 235U integrally bonded to its inner walls. Two processes are introduced for electrodepositing uranium on to the inner walls of the vessel. One processes is electrodepositing UO2 from UO2(NO3)2-(NH4)2CO4·H2O solution; the other is electrodepositing pure uranium metal from molten salt. Its plating efficiency and plating quantity from a molten bath is higher than UO2 from the aqueous system. (authors)

  7. Dicty_cDB: CFJ235 [Dicty_cDB

    Full Text Available TTGTGTTGATGCTT CAACATGGCAATCCTATTCTGGTGGTATTATTACAACTGGTTGTGGTAAAAACATTGATC ATTGTGTTCAAGTA Length of 3' end seq. 554 Connect...ed seq. ID CFJ235P Connected seq. >CFJ235P.Seq ATATCAGTTTTACATCTTTTTTAAATATATATCTACTATATCTAA...ATTACAACTGGTTGTGGTAAAAACATTGATC ATTGTGTTCAAGTA Length of connected seq. 664 Full length Seq ID - Full length Seq. - Length of full length seq. - ... ...D859313.1 F15.001A09F020226 F15 Pisum sativum cDNA clone F15001A09, mRNA sequence. 48 5e-08 2 U19267 |U19267.1 Zinn...CF (Link to library) CFJ235 (Link to dictyBase) - - - Contig-U07719-1 CFJ235P (Link

  8. Multipole components of 235U photofission

    The absolute electrofission cross section for 235U has been experimentally obtained in the energy range 5.8 - 18.0 MeV, using the electron beam of the Linear Accelerator of Institute of Physics of the University of Sao Paulo. From a combined analysis of this cross section and a previously measured photofission cross section, using virtual photon spectra calculated in the Distorted Wave Born Approximation (DWBA), the '' non electric dipole photofission'' cross section σNDEγ,f (ω) has been obtained, which contains all multipolarities allowed by the reaction Kinematics, except El. This cross section presents a resonant shape, probably associated with the Giant Quadrupole Resonance (GQR). Once the fission channel exhausts a great amount of the Energy Weighted Sum Rule (EWSR), it is therefore the major decay mode of the GQR. All these aspects agree with the ones verified for the other Uranium isotopes previously analysed in this Laboratory. (author)

  9. 31 CFR 235.4 - Check Forgery Insurance Fund.

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Check Forgery Insurance Fund. 235.4... SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE ISSUANCE OF SETTLEMENT CHECKS FOR FORGED CHECKS DRAWN ON DESIGNATED DEPOSITARIES § 235.4 Check Forgery Insurance Fund. The Check Forgery...

  10. Dicty_cDB: CHG235 [Dicty_cDB

    Full Text Available CH (Link to library) CHG235 (Link to dictyBase) - - - Contig-U16308-1 CHG235P (Link to Original ... .10.25 Translated Amino Acid sequence k*NSFNNNNLIFFIVF KDIMKNFYYFILILLFFNEVCYSLKDGEIKLHLIPHSHCDSGWT STMNEY ... NPINTKQTKITLYP SEIKAMKLLIIKI Frame B: k*NSFNNNNLIFFIVF KDIMKNFYYFILILLFFNEVCYSLKDGEIKLHLIPHSHCDSGWT STMNEY ...

  11. Dicty_cDB: SHE235 [Dicty_cDB

    Full Text Available SH (Link to library) SHE235 (Link to dictyBase) - - - Contig-U15792-1 SHE235P (Link to Original ... |DV426996.1 NADY185TR Aedes aegypti infected with Dengue ... virus Pool library Aedes aegypti cDNA clone NADY18 ...

  12. Dicty_cDB: CHQ235 [Dicty_cDB

    Full Text Available CH (Link to library) CHQ235 (Link to dictyBase) - - - Contig-U11840-1 | Contig-U13129-1 CHQ235P ... mplete sequence. 149 2e-93 11 AF288090 |AF288090.1 Rhodomonas ... salina mitochondrial DNA, complete genome. 88 8e-1 ...

  13. 33 CFR 162.235 - Puget Sound Area, Wash.

    2010-07-01

    ...: The Corps of Engineers also has regulations dealing with this section in 33 CFR Part 207. ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Puget Sound Area, Wash. 162.235...) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.235 Puget Sound Area, Wash....

  14. Observation of the uranium 235 nuclear magnetic resonance signal

    Le Bail, H.; Chachaty, C.; Rigny, P.; Bougon, R.

    1983-01-01

    The first observation of the nuclear magnetic resonance of the uranium 235 is reported. It has been performed on pure liquid uranium hexafluoride at 380 K. The measured magnetogyric ratio is | γ(235U) | = 492.6 ± 0.2 rad.s-1 G-1.

  15. Nuclear Excitation by Electronic Transition of U-235

    Chodash, Perry Adam [Univ. of California, Berkeley, CA (United States)

    2015-07-14

    Nuclear excitation by electronic transition (NEET) is a rare nuclear excitation that is theorized to occur in numerous isotopes. One isotope in particular, 235U, has been studied several times over the past 40 years and NEET of 235U has never been conclusively observed. These past experiments generated con icting results with some experiments claiming to observe NEET of 235U and others setting limits for the NEET rate. This dissertation discusses the latest attempt to measure NEET of 235U. If NEET of 235U were to occur, 235mU would be created. 235mU decays by internal conversion with a decay energy of 76 eV and a half-life of 26 minutes. A pulsed Nd:YAG laser operating at 1064 nm with a pulse energy of 789 mJ and a pulse width of 9 ns was used to generate a uranium plasma. The plasma was captured on a catcher plate and electrons emitted from the catcher plate were accelerated and focused onto a microchannel plate detector. A decay of 26 minutes would suggest the creation of 235mU and the possibility that NEET occurred. However, measurements performed using a variety of uranium targets spanning depleted uranium up to 99.4% enriched uranium did not observe a 26 minute decay. Numerous other decays were observed with half-lives ranging from minutes up to hundreds of minutes. While NEET of 235U was not observed during this experiment, an upper limit for the NEET rate of 235U was determined. In addition, explanations for the con icting results from previous experiments are given. Based on the results of this experiment and the previous experiments looking for NEET of 235U, it is likely that NEET of 235U has never been observed.

  16. Assay Method for 235U in Low-Density Waste

    2008-01-01

    <正>235U assay method will provide a semi-quantitative assay for any uranium lumps that might exist in low-density, low-Z material waste boxes within a short count time. These materials will consist of

  17. Monsanto Gives Washington U. $23.5 Million.

    Culliton, Barbara J.

    1982-01-01

    Reviews various provisions of a five-year, $23.5-million research agreement between Washington University and the Monsanto Company. The scientific focus of this venture will be on proteins and peptides which modify cellular behavior. (SK)

  18. Direct measurement of uranium 235 concentration in uranium hexafluoride containers

    A simple, portable and autonomous apparatus is described. Isotopic ratio of uranium 235 can be determined in UF6 containers (type 30B or 48Y) without contact with the fissile material. A thermal neutron source induces, through the container wall, nuclear fissions. Fast neutrons produced by the nuclear reaction are detected and counted giving the concentration in uranium 235. Results obtained are presented and discussed

  19. Dicty_cDB: SHH235 [Dicty_cDB

    Full Text Available SH (Link to library) SHH235 (Link to dictyBase) - G23190 DDB0230077 Contig-U16076-1 SHH235P (Lin ... 24 |AF454824.1 Enterococcus faecalis pathogenicity island , complete sequence. 42 2e-04 9 AC116984 |AC116984. ... 999.1 Enterococcus faecalis putative pathogenicity island , partial sequence. 42 7e-04 5 dna update 2006. 4. ...

  20. Nuclear excitation by electronic transition of 235U

    Chodash, P. A.; Burke, J. T.; Norman, E. B.; Wilks, S. C.; Casperson, R. J.; Fisher, S. E.; Holliday, K. S.; Jeffries, J. R.; Wakeling, M. A.

    2016-03-01

    Background: Nuclear excitation by electronic transition (NEET) is a rare nuclear excitation that can occur in isotopes containing a low-lying nuclear excited state. Over the past 40 yr, several experiments have attempted to measure NEET of 235U and those experiments have yielded conflicting results. Purpose: An experiment was performed to determine whether NEET of 235U occurs and to determine its excitation rate. Method: A pulsed Nd:YAG laser operating at 1064 nm with a pulse energy of 790 mJ and a pulse width of 9 ns was used to generate a uranium plasma. The plasma was collected on a catcher plate and electrons from the catcher plate were accelerated and focused onto a microchannel plate detector. An observation of a decay with a 26-min half-life would suggest the creation of Um235 and the possibility that NEET of 235U occurred. Results: A 26-min decay consistent with the decay of Um235 was not observed and there was no evidence that NEET occurred. An upper limit for the NEET rate of 235U was determined to be λNEETconfidence level of 68.3%. Conclusions: The upper limit determined from this experiment is consistent with most of the past measurements. Discrepancies between this experiment and past measurements can be explained by assuming that past experiments misinterpreted the data.

  1. A U-235 confirmation method with a discriminating view

    Reprocessed spent nuclear fuel that has gone through various stages of chemical processing is currently stored at the INEEL. The material consists of three categories: clean U-235 with radiation readings in the mR/h range, U-235 and fission products up to 900 mR/h, and U-235 with U-232 from 100--200 mR/h. The material is contained in plastic bottles and stored in steel structures consisting of seven vertically arranged individual compartments. A total of forty stacks reside in individual concrete wells. This material is considered hard to measure due to excessive radiation exposure to personnel involved with handling the material during mass and NaI U-235 confirmation measurements for Safeguards inventory purposes. A U-235 confirmation method was developed to assay the individual items in place with the ability to discriminate one item from the other items in the stack. Equipment used with this method includes a portable high-resolution gamma-ray detection system, an appropriate tungsten shield and collimator, and a laser-positioning device. A discrimination control test was incorporated to compare the gamma-ray signal of an item in place to the background signal when the item is removed. Total discrimination of the 186-keV gamma ray signal was achieved

  2. 235Cf anti ν discrepancy and the sulfur discrepancy

    The cantankerous discrepancy among measured values of anti ν for 235Cf appears at last to be nearing a final resolution. A recent review has summarized the progress that has been achieved through revaluation upward by 0.5% of two manganese bath values anti ν and the performance of a new liquid scintillator measurement. A new manganese bath measurement at INEL is in reasonably good agreement with previous manganese bath values of 235Cf anti ν. It now appears that the manganese bath values could still be systematically low by as much as 0.4% because the BNL-325 thermal absorption cross section for sulfur may be as much as 10% low. There is a bona fide discrepancy between measurements of the sulfur cross section by pile oscillators and the values derived from transmission measurements. The resolution of this discrepancy is a prerequisite to the final resolution of the 235Cf anti ν discrepancy. 22 references

  3. Integral cross section measurement of the 235U(n ,n') Um235 reaction in a pulsed reactor

    Bélier, G.; Bond, E. M.; Vieira, D. J.; Authier, N.; Becker, J. A.; Hyneck, D.; Jacquet, X.; Jansen, Y.; Legendre, J.; Macri, R.; Méot, V.; Romain, P.

    2015-04-01

    The integral measurement of the neutron inelastic cross section leading to the 26-minute half-life Um235 isomer in a fission-like neutron spectrum is presented. The experiment has been performed at a pulsed reactor, where the internal conversion decay of the isomer was measured using a dedicated electron detector after activation. The sample preparation, efficiency measurement, irradiation, radiochemistry purification, and isomer decay measurement will be presented. We determined the integral cross section for the 235U(n ,n') Um235 reaction to be 1.00 ±0.13 b . This result supports an evaluation performed with talys-1.4 code with respect to the isomer excitation as well as the total neutron inelastic scattering cross section.

  4. Some 235U reference fission product yield data evaluation

    To satisfy the requirement of application for reference fission product yield data, the data have been and will be continuously evaluated. Present work, in which the reference data for 20 product nuclides from 235U fission were evaluated, is a part of the whole work

  5. 48 CFR 2052.235-70 - Publication of research results.

    2010-10-01

    ... publication in refereed scientific and engineering journals or dissemination to the public of any information... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Publication of research....235-70 Publication of research results. As prescribed in 2035.70(a)(1), the contracting officer...

  6. 48 CFR 235.006-70 - Manufacturing Technology Program.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Manufacturing Technology... CONTRACTING 235.006-70 Manufacturing Technology Program. In accordance with 10 U.S.C. 2521(d), for acquisitions under the Manufacturing Technology Program— (a) Award all contracts using competitive...

  7. 4-Chloro-2,3,5-trifluorobenzoic Acid

    Shuitao Yu

    2015-11-01

    Full Text Available A new tetrahalogenated benzoic acid 4-chloro-2,3,5-trifluorobenzoic acid was synthesized from methyl 2,3,4,5-tetrafluorobenzoate via three steps. The structure of the newly synthesized compound was established by FTIR, NMR, MS and elemental analysis.

  8. 77 FR 29986 - Savannah River Site Building 235-F Safety

    2012-05-21

    ... site workers who are normally in the facilities, construction sites, and trailers located adjacent to... Solidification Building construction sites to examine how these facilities would respond to a significant... facilities, construction sites, and trailers located adjacent to Building 235-F. Development of this...

  9. Dicty_cDB: SLI235 [Dicty_cDB

    Full Text Available SL (Link to library) SLI235 (Link to dictyBase) - G24235 DDB0191526 Contig-U01384-1 | Contig-U12 ... ****lkklkkkktlii Frame B: yhskhsrtsw*igsrs*rlkesig*skw *nh*rcwyir*syr*yqskigscyqslccshk *fyhptklikcc*nr*** ...

  10. 29 CFR 99.235 - Program-specific audits.

    2010-07-01

    ... § 99.235 Program-specific audits. (a) Program-specific audit guide available. In many cases, a program-specific audit guide will be available to provide specific guidance to the auditor with respect to internal control, compliance requirements, suggested audit procedures, and audit reporting requirements....

  11. 24 CFR 235.230 - Condition of multifamily structure.

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Condition of multifamily structure... Involving Condominium Units § 235.230 Condition of multifamily structure. (a) When a family unit is conveyed... principal rating organization doing business in the state. If the property is located in a state which...

  12. 46 CFR 172.235 - Extent of damage.

    2010-10-01

    ... BULK CARGOES Special Rules Pertaining to Great Lakes Dry Bulk Cargo Vessels § 172.235 Extent of damage... Damage Collision Penetration Longitudinal extent 0.495 L2/3 or 47.6 feet. (1/3 L2/3 or 14.5 m),...

  13. 24 CFR 8.29 - Homeownership programs (sections 235(i) and 235(j), Turnkey III and Indian housing mutual self...

    2010-04-01

    ... order to accommodate his or her specific handicap. The cost of making a facility accessible under this... the extent such costs exceed allowable mortgage limits, they may be passed on to the prospective homebuyer, subject to maximum sales price limitations (see 24 CFR 235.320.)...

  14. 22 CFR 23.5 - Claims for settlement by Department of State or General Accounting Office.

    2010-04-01

    ... General Accounting Office. 23.5 Section 23.5 Foreign Relations DEPARTMENT OF STATE FEES AND FUNDS FINANCE AND ACCOUNTING § 23.5 Claims for settlement by Department of State or General Accounting Office. Claims for settlement by the Department of State or by the General Accounting Office shall be...

  15. 16 CFR 23.5 - Misuse of the word “vermeil.”

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Misuse of the word âvermeil.â 23.5 Section 23.5 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES FOR THE JEWELRY, PRECIOUS METALS, AND PEWTER INDUSTRIES § 23.5 Misuse of the word “vermeil.” (a) It is unfair...

  16. 24 CFR 235.331 - Increased maximum mortgage amount for physically handicapped persons.

    2010-04-01

    ... for physically handicapped persons. 235.331 Section 235.331 Housing and Urban Development Regulations... maximum mortgage amount for physically handicapped persons. If the mortgage relates to a dwelling unit to be occupied by a handicapped person as defined in § 235.5(c)(2), the otherwise applicable...

  17. 48 CFR 235.015-70 - Special use allowances for research facilities acquired by educational institutions.

    2010-10-01

    ... research facilities acquired by educational institutions. 235.015-70 Section 235.015-70 Federal Acquisition... CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 235.015-70 Special use allowances for research facilities acquired by educational institutions. (a) Definitions. As used in this subsection— (1) Research...

  18. 41 CFR 102-41.235 - May we sell forfeited drug paraphernalia?

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false May we sell forfeited drug paraphernalia? 102-41.235 Section 102-41.235 Public Contracts and Property Management Federal... Requiring Special Handling Drug Paraphernalia § 102-41.235 May we sell forfeited drug paraphernalia? No,...

  19. Preliminary Study on the Determination of ~(235)U and ~(239)Pu Using Delayed Neutron Counting Method

    2011-01-01

    The preliminary study on the fast measurements of 235U and 239Pu in samples containing 235U, 239Pu and 235U-239Pu mixture using delayed neutron counting method is introduced. All samples were irradiated for 30 s using the 30 kW Miniature Neutron

  20. 48 CFR 1852.235-74 - Additional Reports of Work-Research and Development.

    2010-10-01

    ...-Research and Development. 1852.235-74 Section 1852.235-74 Federal Acquisition Regulations System NATIONAL... Provisions and Clauses 1852.235-74 Additional Reports of Work—Research and Development. As prescribed in 1835.070(e), insert a clause substantially the same as the following: Additional Reports of...

  1. 41 CFR 102-117.235 - How do I get a cost comparison?

    2010-07-01

    ... MANAGEMENT Shipping Household Goods § 102-117.235 How do I get a cost comparison? (a) You may calculate a cost comparison internally according to 41 CFR 302-8.3. (b) You may request GSA to perform the cost... comparison? 102-117.235 Section 102-117.235 Public Contracts and Property Management Federal...

  2. Building 235-F Goldsim Fate And Transport Model

    Taylor, G. A.; Phifer, M. A.

    2012-09-14

    Savannah River National Laboratory (SRNL) personnel, at the request of Area Completion Projects (ACP), evaluated In-Situ Disposal (ISD) alternatives that are under consideration for deactivation and decommissioning (D&D) of Building 235-F and the Building 294-2F Sand Filter. SRNL personnel developed and used a GoldSim fate and transport model, which is consistent with Musall 2012, to evaluate relative to groundwater protection, ISD alternatives that involve either source removal and/or the grouting of portions or all of 235-F. This evaluation was conducted through the development and use of a Building 235-F GoldSim fate and transport model. The model simulates contaminant release from four 235-F process areas and the 294-2F Sand Filter. In addition, it simulates the fate and transport through the vadose zone, the Upper Three Runs (UTR) aquifer, and the Upper Three Runs (UTR) creek. The model is designed as a stochastic model, and as such it can provide both deterministic and stochastic (probabilistic) results. The results show that the median radium activity concentrations exceed the 5 ?Ci/L radium MCL at the edge of the building for all ISD alternatives after 10,000 years, except those with a sufficient amount of inventory removed. A very interesting result was that grouting was shown to basically have minimal effect on the radium activity concentration. During the first 1,000 years grouting may have some small positive benefit relative to radium, however after that it may have a slightly deleterious effect. The Pb-210 results, relative to its 0.06 ?Ci/L PRG, are essentially identical to the radium results, but the Pb-210 results exhibit a lesser degree of exceedance. In summary, some level of inventory removal will be required to ensure that groundwater standards are met.

  3. Composite delayed-neutron spectra from U-235

    Delayed-neutron spectra from thermal neutron-induced fission of U-235 have been measured over the neutron energy range, .01 - 2.0 MeV, for delay times following fission ranging from 0.17 - 85.5 s. A helium jet system was used for the rapid transport of fission products to a low-background area, where the spectra were determined from beta-neutron correlations using the neutron time-of-flight method

  4. Sistem Pakar Pada Perangkat Mobile Untuk Mendeteksi Kerusakan Docucenter 235

    Azhary, M. Fadli

    2011-01-01

    Development for mobile device is relieve to give efficient and faster information. Expert system is subdivision of artificial intelligence for solving in expert human problems. This study for implementation expert system working with backward chaining method that compatible for diagnose. In implementation, system giving user option “Yes” or “No” for answer some question. Those questions are pack based on technician experience and from guide book to solve troubleshooting for Docucenter 235. Th...

  5. Building 235-F Goldsim Fate And Transport Model

    Savannah River National Laboratory (SRNL) personnel, at the request of Area Completion Projects (ACP), evaluated In-Situ Disposal (ISD) alternatives that are under consideration for deactivation and decommissioning (D and D) of Building 235-F and the Building 294-2F Sand Filter. SRNL personnel developed and used a GoldSim fate and transport model, which is consistent with Musall 2012, to evaluate relative to groundwater protection, ISD alternatives that involve either source removal and/or the grouting of portions or all of 235-F. This evaluation was conducted through the development and use of a Building 235-F GoldSim fate and transport model. The model simulates contaminant release from four 235-F process areas and the 294-2F Sand Filter. In addition, it simulates the fate and transport through the vadose zone, the Upper Three Runs (UTR) aquifer, and the Upper Three Runs (UTR) creek. The model is designed as a stochastic model, and as such it can provide both deterministic and stochastic (probabilistic) results. The results show that the median radium activity concentrations exceed the 5 ρCi/L radium MCL at the edge of the building for all ISD alternatives after 10,000 years, except those with a sufficient amount of inventory removed. A very interesting result was that grouting was shown to basically have minimal effect on the radium activity concentration. During the first 1,000 years grouting may have some small positive benefit relative to radium, however after that it may have a slightly deleterious effect. The Pb-210 results, relative to its 0.06 ρCi/L PRG, are essentially identical to the radium results, but the Pb-210 results exhibit a lesser degree of exceedance. In summary, some level of inventory removal will be required to ensure that groundwater standards are met

  6. Overview of recent U235 neutron cross section evaluation work

    Lubitz, C. [Lockheed Martin Corp., Schenectady, NY (United States)

    1998-10-01

    This report is an overview (through 1997) of the U235 neutron cross section evaluation work at Oak Ridge National Laboratory (ORNL), AEA Technology (Harwell) and Lockheed Martin Corp.-Schenectady (LMS), which has influenced, or appeared in, ENDF/B-VI through Release 5. The discussion is restricted to the thermal and resolved resonance regions, apart from some questions about the unresolved region which still need investigation. The important role which benchmark testing has played will be touched on.

  7. Activity of BKM120 and BEZ235 against Lymphoma Cells

    Monica Civallero

    2015-01-01

    Full Text Available Non-Hodgkin lymphomas encompass a heterogeneous group of cancers, with 85–90% arising from B lymphocytes and the remainder deriving from T lymphocytes or NK lymphocytes. These tumors are molecularly and clinically heterogeneous, showing dramatically different responses and outcomes with standard therapies. Deregulated PI3K signaling is linked to oncogenesis and disease progression in hematologic malignancies and in a variety of solid tumors and apparently enhances resistance to antineoplastic therapy, resulting in a poor prognosis. Here, we have evaluated and compared the effects of the pan-PI3K inhibitor BKM120 and the dual PI3K/mTOR inhibitor BEZ235 on mantle, follicular, and T-cell lymphomas. Our results suggest that BKM120 and BEZ235 can effectively inhibit lymphoma cell proliferation by causing cell cycle arrest and can lead to cell death by inducing apoptosis and autophagy mediated by ROS accumulation. Despite great advances in lymphoma therapy after the introduction of monoclonal antibodies, many patients still die from disease progression. Therefore, novel treatment approaches are needed. BKM120 and BEZ235 alone and in combination are very effective against lymphoma cells in vitro. If further studies confirm their effectiveness in animal models, they may be promising candidates for development as new drugs.

  8. Calculation of resonance self-shielding in 235U

    The self-shielded fission rates for 235U measured by Czirr have been computed in the 0.464- to 464-eV range with the 235U resolved resonance parameters of the current version of ENDF/B-VI. The main purpose of describing the neutron cross sections of the fissile isotopes with resonance parameters is for the calculation of resonance self-shielding in reactors. Czirr has measured the relative self-shielded fission rate behind absorber thicknesses varying from 0.5 to 19 g/cm2 of uranium. These measurements have repeatedly been used to test the validity of sets of resonance parameters. However, previous calculations of these experiments were limited and inconclusive. An evaluation of the 235U resolved resonance region extending to 2.2 keV was recently completed and incorporated into ENDF/B-VI. The resonance parameters of this evaluation were used to compute the self-shielded fission rates for energy groups 0 to 8 (energies from 0.464 to 464 eV) of the Czirr measurement

  9. Ternary Fission of U235 by Resonance Neutrons

    Recently a number of papers have appeared indicating considerable variations in the ratio of the ternary-fission cross-section to the binary-fission cross-section of U235 on transition from one neutron resonance to another. However, such variations have not been discovered in U233 and Pu239. The paper reports investigations of the ternary fission of U235 by neutrons with an energy of 0.1 to 30 eV. Unlike other investigators of the ternary fission of U235 , we identified the ternary-fission event by the coincidence of one of the fission fragments with a light long-range particle. This made it passible to separate ternary fissions from the possible contribution of the (n, α)reaction. The measurements were performed at the fast pulsed reactor of the Joint Institute for Nuclear Research by the time-of-flight method. A flight length of 100 m was used, giving a resolution of 0.6 μs/m. Gas scintillation counters filled with xenon at a pressure of 2 atm were used to record the fission fragments and the light long-range particle. A layer of enriched U235 ∼2 mg/cm2 thick and ∼300 cm2 in area was applied to an aluminium foil 20-fim thick. The scintillations from the fission fragments were recorded in the gas volume on one side of the foil and those from the light long-range particles in that on the other. In order to assess the background (e.g . coincidences of the pulse from a fragment with that from a fission gamma quantum or a proton from the (n, p) reaction in the aluminium foil), a measurement was carried out in which the volume recording the long-range particle was shielded with a supplementary aluminium filter 1-mm thick. The results obtained indicate the absence of the considerable variations in the ratio between the ternary-and binary- fission cross-sections for U235 that have been noted by other authors. Measurements showed no irregularity in the ratio of the cross-sections in the energy range 0.1 to 0.2 eV. The paper discusses the possible effect of the (n,

  10. Different evolutionary stages in S235A-B

    Felli, Marcello; Massi, Fabrizio; Cesaroni, Riccardo

    The star forming region S235A-B has been studied at high resolution with radio (IRAM Interferometer and VLA) and infrared (JCMT and Spitzer) observations. The region was mapped in HCO^+, C^34S, H[2]CS, SO[2] and CH[3]CN as well as in the 1.2 and 3.3 continuum, in the cm continuum at 6, 3.6, 1.3 and 0.7 cm and in the 22 GHz water maser line, in the far infrared at 450 and 850 micron and in the mid infrared from 3.6 to 8 micron. Use was made of the Medicina water maser patrol, from 1987 to 2005, to study the maser variability. S235A is a classical HII region, well resolved and with a very good match between radio and infrared images. To the south of it, molecular and continuum mm observations as well as infrared observations reveal the presence of newly formed YSOs placed in between S235A and S235B: a molecular core and an unresolved mm source centred on one maser component, with indication of mass infall onto the core. Two bipolar outflows and a jet originate from the same position. No cm radio continuum emission is detected either from the compact molecular core or from the jet-like structure, suggesting emission from dust in both cases. Evidence is found for a molecular rotating disk perpendicular to the main bipolar outflow. The derived parameters indicate that the YSO is an intermediate luminosity object in a very early evolutionary phase. Its main source of energy could come from gravitational infall thus making this YSO a rare link between the earliest evolutionary phases of massive stars and low mass protostars of class 0-I. Two compact radio continuum sources (VLA-1 and VLA-2) and three separate maser spots were found. VLA-1 coincides with one of the maser spots and with an IR source (M1). VLA-2 lies towards S235B and represents the first radio detection from this peculiar nebula. The two other maser spots coincide with the rotating disk perpendicular to the bipolar molecular outflow. The Spitzer images reveal a red object towards the molecular core which is

  11. Evaluation of 235U(n,f) above 100 keV for ENDF/B-V and the implications of a unified 235U mass scale

    A previously reported evaluation of 235U(n,f) in the fast neutron energy range was updated to include data published up to the 1978 Harwell Conference on Neutron Physics. The shape of the cross section resulting from this evaluation and a normalization factor extracted from data provided within the framework of this evaluation were used by the Subcommittee on Standards and Normalizations of the Cross Section Evaluation Working Group to establish 235U(n,f) for ENDF/B-V above 100 keV. The 235U sample mass comparisons made between different laboratories were compiled in order to investigate the implications of different sample masses on recent 235U(n,f) data. A new intercomparison of several such samples was carried out using absolute and relative alpha-counting and relative fast neutron fission counting. The result of this work is a unified 235U mass scale with an uncertainty of 0.6%. 39 references

  12. Neutron induced fission of 235sub(U)

    In order to achieve a better understanding of the fision process it is essential to get experimental data on the details of the mass, energy and angular distributions, and the mass versus energy and mass versus angular distribution correlations as function of excitation energy. The present work describes the result of such a measurement for 235U(n,f) with thermal 235U(n,f) reaction has a rather high cross section, especially for thermal neutrons. The changes in the average total kinetic energy relative to the thermal value have been measured at several neutron energies above thermal, and the angular anisotropy of the fission fragments averaged over all fragment masses has been determined in several measurements. Many of the thermal values, the average kinetic energy and average angular anisotropy values at higher neutron energies were compared with measurements using other techniques. Good agreement is found. It indicates that the chamber works as intended and it gives confidence to the data measured for the first time with the present setup. It furthermore allows to use the chamber with confidence in future measurements on less known fission reactions and at less explored excitation energies of the compound nucleus. (author)

  13. Resonance structure in the fission of (235U+n)

    A new multilevel reduced R-matrix analysis of the neutron-induced resonance cross sections of 235U has been carried out. We used as a constraint in the analysis the angular anisotropy measurements of Pattenden and Postma, obtaining a Bohr-channel (or J, K channel) representation of the resonances in a two-fission vector space for each spin state. Hambsch et al., have reported definitive measurements of the mass- and kinetic-energy distributions of fission fragments of (235U+n) in the resonance region and analyzed their results according to the fission-channel representation of Brosa et al., extracting relative contributions of the two asymmetric and one symmetric Brosa fission channels. We have explored the connection between Bohr-channel and asymmetric Brosa-channel representations. The results suggest that a simple rotation of coordinates in channel space may be the only transformation required; the multilevel fit to the total and partial cross sections is invariant to such a transformation. (orig.)

  14. 238UF6 and 235UF6 spectra measurement in mid IR spectral range

    Making use of a diode laser one measured the absorption spectra of 238UF6 and 235UF6 molecules within v1+v3 combined oscillation band at λ=7.68 μm wavelength. To determine the possibility to measure 235UF6/ 238UF6 isotope ratio with the required accuracy one measured the absorption factors of 235UF6 and 238UF6 isotope specimens and determined the sources of the errors and the ways to minimize them

  15. 235U Holdup Measurement Program in support of facility shutdown

    In 1989, the Department of Energy directed shutdown of an enriched uranium processing facility at Savannah River Site. As part of the shutdown requirements, deinventory and cleanout of process equipment and nondestructive measurement of the remaining 235U holdup were required. The holdup measurements had safeguards, accountability, and nuclear criticality safety significance; therefore, a technically defensible and well-documented holdup measurement program was needed. Appropriate standards were fabricated, measurement techniques were selected, and an aggressive schedule was followed. Early in the program, offsite experts reviewed the measurement program, and their recommendations were adopted. Contact and far-field methods were used for most measurements, but some process equipment required special attention. All holdup measurements were documented, and each report was subjected to internal peer review. Some measured values were checked against values obtained by other methods; agreement was generally good

  16. Isotopic analysis of uranium hexafluoride highly enriched in U-235

    Isotopic analysis of uranium in the form of the hexafluoride by mass-spectrometry gives gross results which are not very accurate. Using a linear interpolation method applied to two standards it is possible to correct for this inaccuracy as long as the isotopic concentrations are less than about 10 per cent in U-235. Above this level, the interpolations formula overestimates the results, especially if the enrichment of the analyzed samples is higher than 1.3 with respect to the standards. A formula is proposed for correcting the interpolation equation and for the extending its field of application to high values of the enrichment (≅2) and of the concentration. It is shown that by using this correction the results obtained have an accuracy which depends practically only on that of the standards, taking into account the dispersion in the measurements. (authors)

  17. Adolescent idiopathic scoliosis: Retrospective analysis of 235 surgically treated cases

    Unnikrishnan Ranjith

    2010-01-01

    Full Text Available Background : The surgical treatment of adolescent idiopathic scoliosis (AIS has taken great strides in the last two decades. There have been no long term reported studies on AIS from India with documented long term followup. In this study we review a single surgical team′s series of 235 surgically treated cases of AIS with a follow-up from two to six years. Materials and Methods : Pre operative charts, radiographs and MRI scans for 235 patients were collected for this study. The patients were grouped into three groups where anterior correction and fusion (n=47, posterior correction and fusion (n=123 and combined anterior release and posterior instrumentation (n=65 was performed. Each group was divided into two subgroups based on the surgical approach and instrumentation strategy (all screw construct or hybrid construct used. Patients were followed up for coronal and saggital plane corrections, apical vertebral translation (AVT, trunk balance and back pain. The percentage of correction was calculated in each group as well as sub groups. Results : The incidence of MRI detected intraspinal anomaly in this series is 5.9% with 3.4% of them requiring neurosurgical procedure along with scoliosis correction. Average coronal major curve correction was 66% in the all screw group and 58.5% in the hybrid group. The coronal plane correction was better when the all screw constructs were employed. Also, the AVT and trunk balance was better with the all screw constructs. The anterior corrections resulted in better correction of the AVT and trunk balance as compared to the posterior correction. There were eight (3.4% complications in this series. The coronal and saggital plane correction paralleled the published international standards. Conclusion : The coronal plane correction was better when all screw constructs were employed. Use of all pedicle screw systems obviated the need for costoplasty in most cases. The increased incidence of intraspinal anomaly may

  18. Uranium-235 and childhood leukaemia around Greenham Common airfield

    There has been considerable publicity recently concerning the possible release of enriched uranium from the Greenham Common USAF base near Newbury in Berkshire. Evidence for the release relies on an internal report of the Atomic Weapons Research Establishment at Aldermaston, the authors of which postulated that it resulted from a fire in 1958 involving a B47 bomber standing on the runway. Their report contained a much publicised contour map of excess 235U levels estimated from the ratio of 235U to 238U in 26 evergreen leaf samples examined. The current concern of the inhabitants of Newbury centres mostly on the incidence of leukaemia, which was known beforehand to be slightly elevated in parts of West Berkshire, at least for young children. A number of cases have received considerable press publicity, with suggestions that their homes are located close to the base or the flight-path. The reports are, however, anecdotal and are not based on a complete register of cases. We have examined the evidence for this putative association by re-analysing the uranium data and determining the spatial relationship to the base of cases of childhood leukaemia diagnosed in the years 1966-87. We conclude that, although the excess uranium found has a non-random distribution, it does not support the pattern depicted by the contours and bears no relation to the incidence of childhood leukaemia for the period we examined. In any case, the increase in level of environmental radiation as a result of the putative release must be very small and is at variance with the reporting in some of the national press. (author)

  19. Dispersion of the Neutron Emission in U{sup 235} Fission

    Feynman, R. P.; de Hoffmann, F.; Serber, R.

    1955-01-01

    Equations are developed which allow the calculation of the average number of neutrons per U{sup235} fission from experimental measurements. Experimental methods are described, the results of which give a value of (7.8 + 0.6){sup ½} neutrons per U{sup 235} thermal fission.

  20. 24 CFR 990.235 - PHAs that will experience a subsidy increase.

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false PHAs that will experience a subsidy increase. 990.235 Section 990.235 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT THE...

  1. 40 CFR 80.235 - How does a refiner obtain approval as a small refiner?

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false How does a refiner obtain approval as a small refiner? 80.235 Section 80.235 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...) The small refiner status application must contain the following information for the company...

  2. R-matrix analyses of the 235U and 239Pu neutron cross sections

    The resonance parameter analysis code SAMMY was used to perform consistent resonance analyses of several 235U and 239Pu fission and capture cross section and transmission measurements up to 110 eV for 235U and up to 1 keV for 239Pu. The method of analysis, the measurement selection and the results are briefly outlined in this paper

  3. 15 CFR 23.5 - Report to the Office of Juvenile Justice and Delinquency Prevention.

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Report to the Office of Juvenile Justice and Delinquency Prevention. 23.5 Section 23.5 Commerce and Foreign Trade Office of the Secretary... Office of Juvenile Justice and Delinquency Prevention. The Department of Commerce will compile and...

  4. Determination of 235U/238U Ratio on Urine by ICP-MS

    LLNL Internal Dosimetry Program - The new procedure satisfies the requirement to determine 235U/238U ratio in bioassay urine samples. MDA - The LC and MDA95 for 235U are well below the required detection limit of 0.00035 μg/L. Turn around time - Analysis of 10 samples plus 2 QCs can be completed in one work day (8 hours).

  5. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    2010-07-01

    ... nitrogen. 52.235 Section 52.235 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay... the area from implementing the oxides of nitrogen (NOX) requirements for reasonably available...

  6. 46 CFR 10.235 - Suspension or revocation of merchant mariner credentials.

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Suspension or revocation of merchant mariner credentials. 10.235 Section 10.235 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MERCHANT MARINER CREDENTIAL General Requirements for All Merchant Mariner Credentials §...

  7. 235例院前急救分析

    王海全

    2005-01-01

    目的:探讨院前急救的特点.方法:回顾性分析235例院前急救的疾病分类及心肺复苏(CPR)成功率状况.结果:需现场急救的疾病前3位是脑血管疾病、外科急症、心血管疾病,分别占26.38%、23.38%和17.45%;现场需CPR者53例,40~45岁以下以车祸、坠楼、中毒、意外居多,60岁以上以心、脑血管疾病为主,CPR成功率低,仅5.66%,主要与CPR开始时间延迟相关.结论:院前急救的重点是心、脑血管疾病和外伤;缩短CPR开始时间,提高CPR抢救成功率.

  8. Simulated (n,f) cross section of isomeric 235m-U

    The neutron-induced fission cross section on the 235U, T1/2 ∼ 26 min isomer has been deduced for incident neutron energies in the range En=0.1-2.5 MeV, using the surrogate-reaction technique. In this technique, 236U fission probabilities measured in the 234U(t, pf) reaction have been converted into 235U(n,f) and 235mU(n,f) cross sections, using reaction theory to compensate for the differences in angular-momentum and parity distributions in the fissioning systems, transferred by the (t,p) and neutron-induced reactions. Based on the comparison between the 235U(n,f) cross section extracted in this work and independent experimental data, the deduced 235mU(n,f) cross section is believed to be reliable to 20% below En ∼ 0.5 MeV and 10% at higher energies. The surrogate-reaction technique, its validation in the case of the 235U(n,f) cross section, and the deduced 235mU(n,f) cross section are discussed. Validation of this method allows (n,f) cross sections for many short-lived nuclei, as well as isomeric nuclei, to be extracted from measured fission probabilities

  9. 21 CFR 2.35 - Use of secondhand containers for the shipment or storage of food and animal feed.

    2010-04-01

    ... storage of food and animal feed. 2.35 Section 2.35 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... Foods § 2.35 Use of secondhand containers for the shipment or storage of food and animal feed. (a... State public health agencies have revealed practices whereby food and animal feed stored or shipped...

  10. DM235 (sunifiram): a novel nootropic with potential as a cognitive enhancer

    Ghelardini C; Galeotti N.; Gualtieri F.; Romanelli M; Bucherelli C.; Baldi E.; Bartolini A.

    2002-01-01

    DM235 (sunifiram), a new compound structurally related to piracetam, prevented the amnesia induced by scopolamine (1.5 mg kg–1 i.p.), after intraperitoneal (0.001–0.1 mg kg–1) or oral (0.01–0.1 mg kg–1) administration, as shown by a passive avoidance test in mice. The antiamnesic effect of DM235 was comparable to that of well-known nootropic drugs such as piracetam (30–100 mg kg–1 i.p.), aniracetam (100 mg kg–1 p.o.) or rolipram (30 mg kg–1 p.o.). DM235 also prevented mecamylamine (20 mg kg–1...

  11. Prompt-Neutron Emission from U235 Fission Fragments

    A gadolinium-loaded large liquid scintillation counter is being used in conjunction with a neutron beam from the HERALD reactor at the Atomic Weapons Research Establishment, Aldermaston, to study neutron emission in the fission process. In particular, the neutron emission from individual fission fragments is observed. A fission-fragment detector comprising two gold-silicon suríace barrier counters operating in coincidence is situated at the edge of a 1-m-diam. spherical scintillation tank. The solid-state counters are placed on opposite sides of an evaporated fissile deposit on a thin nickel backing. A system of collimators selects for measurement only those fission events that have fragments travelling in the direction along the incident neutron beam and along the axis of the scintillator. Numbers of neutrons detected within 10 ps of a fission event are recorded. The angular correlation of neutron emission with fragment direction is used to associate the neutrons with the particular fission fragment that emitted them. Energies of both fragments are available from the solid-state counters, and identification of fragment mass and of the total kinetic energy of the fragment pair is made. The number of neutrons emitted by each fragment of the pair has been measured as a function of both the fragment mass and the total kinetic energy of the pair for thermal neutrons incident on U2'35. The usual asymmetry in the distribution of excitation energy between the heavy and light fragments is observed. The variation of the number of neutrons from the pair as a function of mass ratio is also determined. (author)

  12. U-235 sample-mass determinations and intercomparisons

    The neutron-induced fission cross section of U-235 is not only one of the most-frequently used references but is also of direct importance in reactor applications. As a consequence, knowledge of this cross section is required with approx. 1% uncertainty as reflected in corresponding entries in request lists, which have persisted since the last 10 to 15 years. Measurements to that level of accuracy require the investigation of the contributing components, one of which is the fission mass. The latter is most often determined by others than the experimenter who measures the differential cross sections or integral reaction-rate ratios in a reactor test facility. The isotopic composition and the sample mass are usually obtained from associated chemistry departments or standard laboratories, however, the experimenter has still the responsibility to assure that the values he uses are adequately described by the quoted uncertainties. This can be achieved by comparing samples from different origins. It was in this spirit that an intercomparison of fission samples obtained from different US laboratories, which were involved in cross section measurements, was carried out in 1979. The notable outcome of this effort was that a bias of approx. 0.7% was found between the standard laboratory and other contributing laboratories (which was, however, within the stated uncertainty). The National Bureau of Standards (NBS) has since then worked on a redefinition of the mass assignments of its reference samples, has revised its mass scale by 0.8%, and has reduced its uncertainty by a factor of two (to about +-0.5%). However, this new mass scale includes values relative to others. In the present work these have been removed in order to compare mass scales as independent from one another as possible. Independence already appears hard to come by. Results are presented

  13. Targeted disruption of py235ebp-1: Invasion of erythrocytes by Plasmodium yoelii using an alternative py235 erythrocyte binding protein

    Ogun, Solabomi A.

    2011-02-17

    Plasmodium yoelii YM asexual blood stage parasites express multiple members of the py235 gene family, part of the super-family of genes including those coding for Plasmodium vivax reticulocyte binding proteins and Plasmodium falciparum RH proteins. We previously identified a Py235 erythrocyte binding protein (Py235EBP-1, encoded by the PY01365 gene) that is recognized by protective mAb 25.77. Proteins recognized by a second protective mAb 25.37 have been identified by mass spectrometry and are encoded by two genes, PY01185 and PY05995/PY03534. We deleted the PY01365 gene and examined the phenotype. The expression of the members of the py235 family in both the WT and gene deletion parasites was measured by quantitative RT-PCR and RNA-Seq. py235ebp-1 expression was undetectable in the knockout parasite, but transcription of other members of the family was essentially unaffected. The knockout parasites continued to react with mAb 25.77; and the 25.77-binding proteins in these parasites were the PY01185 and PY05995/PY03534 products. The PY01185 product was also identified as erythrocyte binding. There was no clear change in erythrocyte invasion profile suggesting that the PY01185 gene product (designated PY235EBP-2) is able to fulfill the role of EBP-1 by serving as an invasion ligand although the molecular details of its interaction with erythrocytes have not been examined. The PY01365, PY01185, and PY05995/PY03534 genes are part of a distinct subset of the py235 family. In P. falciparum, the RH protein genes are under epigenetic control and expression correlates with binding to distinct erythrocyte receptors and specific invasion pathways, whereas in P. yoelii YM all the genes are expressed and deletion of one does not result in upregulation of another. We propose that simultaneous expression of multiple Py235 ligands enables invasion of a wide range of host erythrocytes even in the presence of antibodies to one or more of the proteins and that this functional

  14. Inhibition of proliferation in bone tumor cells after irradiation by 235U, 147Pm, 153Sm

    The inhibition of proliferation in bone tumor cells after simple or mixed irradiation by 235U, 147Pm, 153Sm was studied. Experimental results indicated that proliferation of bone tumor cells was significantly inhibited at 12 h∼24 h after a simple irradiation by 235U (128.4 Bq), 147Pm (7.4 x 105 Bq), and 153Sm (7.4 x 105 Bq) as well as mixed irradiation by 235U + 147Pm (64.2 Bq + 3.7 x 105 Bq), 235U + 153Sm (64.2 Bq + 3.7 x 105 Bq), 147Pm + 153Sm (3.7 x 105 Bq + 3.7 x 105 Bq). The findings show that the inhibition rate with mixed irradiation was more than that with simple irradiation

  15. Study of correcting the effect of daughter age on determining 235U enrichment of fuel rods

    Gamma-ray passive technique is a very effective method to assay and determine 235U enrichment of nuclear power plant fuel rods. There is a weakness in this passive method, i.e. only after the uranium isotope daughters of UO2 pellets have reached to equilibrium with uranium parent, then the 235U enrichment can be determined. This weakness greatly restricts the application of the method. A new two-peak and two-window technique is developed that can overcome the interference of uranium daughter decay in determining 235U enrichment of nuclear fuel rods, and the results are very satisfactory. The new technique will play an important role in the gamma-ray passive technique for determining 235U enrichment of fuel rods. This new technique also makes the gamma-ray passive method perfectly. (11 figs., 6 tabs.)

  16. 77 FR 26737 - Foreign-Trade Zone 235-Lakewood, NJ: Notification of Proposed Production Activity; Cosmetic...

    2012-05-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 235--Lakewood, NJ: Notification of Proposed Production Activity; Cosmetic Essence Innovations, LLC (Fragrance Bottling); Holmdel, NJ Cosmetic Essence...

  17. Determination of 235U/238U Ratio on Urine by ICP-MS

    Collins, L; Gobaleza, A; Langston, R; Radev, R; Than, C; Wong, C; Wood-Zika, A

    2011-10-19

    LLNL Internal Dosimetry Program - The new procedure satisfies the requirement to determine {sup 235}U/{sup 238}U ratio in bioassay urine samples. MDA - The L{sub C} and MDA{sub 95} for {sup 235}U are well below the required detection limit of 0.00035 {mu}g/L. Turn around time - Analysis of 10 samples plus 2 QCs can be completed in one work day (8 hours).

  18. Verification of 235U enrichment in SNM receipts at the DOE Feed Materials Production Center

    A diversity of uranium-bearing, nonirradiated materials with 235U assays from fully depleted to a maximum of 10 wt % 235U, is routinely returned to this DOE site for reprocessing. It is necessary to confirm the 235U isotopic content of Special Nuclear Material (SNM) receipts both for accountability and nuclear criticality safety purposed. Methods and instrumentation have been developed for an isotopic verification facility by which 235U isotopic content is rapidly and nondestructively determined. The 185 keV gamma photon emitted by 235U is measured using a dual-channel gamma spectrometer which incorporates automatic background subtraction and an optimized collimator/NaI(Tl) detector assembly. Measured activities are then related to 235U isotopic content by means of appropriate standards that have been destructively analyzed in the laboratory. Use of the described facility for the past seven years has resulted in improved nuclear safety procedures, better use of storage space and more stringent nuclear materials accountability

  19. Fractionation of 238U/235U by reduction during low temperature uranium mineralisation processes

    Murphy, Melissa J.; Stirling, Claudine H.; Kaltenbach, Angela; Turner, Simon P.; Schaefer, Bruce F.

    2014-02-01

    Investigations of ‘stable’ uranium isotope fractionation during low temperature, redox transformations may provide new insights into the usefulness of the 238U/235U isotope system as a tracer of palaeoredox processes. Sandstone-hosted uranium deposits accumulate at an oxidation/reduction interface within an aquifer from the low temperature reduction of soluble U(VI) complexes in groundwaters, forming insoluble U(IV) minerals. This setting provides an ideal environment in which to investigate the effects of redox transformations on 238U/235U fractionation. Here we present the first coupled measurements of 238U/235U isotopic compositions and U concentrations for groundwaters and mineralised sediment samples from the same redox system in the vicinity of the high-grade Pepegoona sandstone-hosted uranium deposit, Australia. The mineralised sediment samples display extremely variable 238U/235U ratios (herein expressed as δUCRM145238, the per-mil deviation from the international NBL standard CRM145). The majority of mineralised sediment samples have δUCRM145238 values between -1.30±0.05 and 0.55±0.12‰, spanning a ca. 2‰ range. However, one sample has an unusually light isotopic composition of -4.13±0.05‰, which suggests a total range of U isotopic variability of up to ca. 5‰, the largest variation found thus far in a single natural redox system. The 238U/235U isotopic signature of the mineralised sediments becomes progressively heavier (enriched in 238U) along the groundwater flow path. The groundwaters show a greater than 2‰ variation in their 238U/235U ratios, ranging from δUCRM145238 values of -2.39±0.07 to -0.71±0.05‰. The majority of the groundwater data exhibit a clear systematic relationship between 238U/235U isotopic composition and U concentration; samples with the lowest U concentrations have the lowest 238U/235U ratios. The preferential incorporation of 238U during reduction of U(VI) to U(IV) and precipitation of uranium minerals leaves

  20. Standard test method for measurement of 235U fraction using enrichment meter principle

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers the quantitative determination of the fraction of 235U in uranium using measurement of the 185.7 keV gamma-ray produced during the decay of 235U. 1.2 This test method is applicable to items containing homogeneous uranium-bearing materials of known chemical composition in which the compound is considered infinitely thick with respect to 185.7 keV gamma-rays. 1.3 This test method can be used for the entire range of 235U fraction as a weight percent, from depleted (0.2 % 235U) to highly enriched (97.5 % 235U). 1.4 Measurement of items that have not reached secular equilibrium between 238U and 234Th may not produce the stated bias when low-resolution detectors are used with the computational method listed in Annex A2. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety co...

  1. Determination of parameters of Johnson-Cook models of Q235 B steel%Q235 B钢Johnson-Cook模型参数的确定

    林莉; 支旭东; 范锋; 孟上九; 苏俊杰

    2014-01-01

    使用万能材料试验机、扭转试验机和霍普金森拉杆装置研究了Q235B钢在常温~950℃的准静态、动态力学性能,获得了Q235 B强度与等效塑性应变,应变率和温度的关系以及延性与应力三轴度,应变率和温度的关系。基于实验结果,修改了Johnson-Cook(J-C)强度模型中的应变强化项以及Johnson-Cook失效模型中的温度软化项,并结合数值仿真标定了相关模型参数。最后通过Taylor撞击试验验证了模型参数的有效性。%Strength and ductility data for Q235 B steel from 20 ℃ to 950 ℃ were obtained from tension tests with smooth cylindrical specimens (SCSs).The strain rate sensitivity was studied by conducting split hopkinson tension bar (SHTB)tests and uniaxial tension tests of SCSs.The influence of stress triaxiality on ductility was revealed by conducting upsetting tests of cylinder specimens,tension tests of pre-notched cylinder specimens and torsion tests of SCSs.Slightly modified versions of two Johnson-Cook (J-C ) models describing flow stress and failure strain were presented to characterize the properties of Q235 B steel as a function of strain rate,temperature and stress triaxiality.The corresponding model parameters were calibrated based on the test data and with the help of finite element simulation.The validity of the model parameters was verified with Taylor impact tests.

  2. Fine structure at the diffusion welded interface of Fe3Al/Q235 dissimilar materials

    Wang Juan; Li Yajiang; Wu Huiqiang

    2001-12-01

    The interface of Fe3Al/Q235 dissimilar materials joint, which was made by vacuum diffusion welding, combines excellently. There are Fe3Al, FeAl phases and -Fe (Al) solid solution at the interface of Fe3Al/Q235. Aluminum content decreases from 28% to 1.5% and corresponding phase changes from Fe3Al with DO3 type body centred cubic (bcc) structure to -Fe (Al) solid solution with B2 type bcc structure. All phases are present in sub-grain structure level and there is no obvious brittle phases or micro-defects such as pores and cracks at the interface of Fe3Al/Q235 diffusion joint.

  3. Determination of 235U isotope abundance by measuring selected pairs of fission products

    A new method to determine experimentally the isotopic abundance of uranium has been developed by measuring the ratios of selected fission product pairs. The relationship between the 235U abundance and the ratios of 14 MeV neutron-induced fission products, which are N(3892Sr)/N(44105Ru) and N(3892Sr)/N(53135I), have been obtained. The results of 4 test samples show that the relative deviations between the measured and the reference 235U abundances are less than ±3%.

  4. Determination of U235 enrichment from nuclear fuel by neutronic activation

    The enrichment of 235U in UO2 pellets samples through the instrumental neutron activation analysis method (I.N.A.A.) was determined. By high resolution gamma-ray spectrometry (H.R.G.S.), from analysis of isotopic ratios between fission products peaks from 235U and 239Np different energies peaks from 238U, the enrichment was achieved. The 'Boatstrap' statistics technique for the analytical results, which is based in shaping results of an unknown distribution to the Gaussian distribution by B replications in interested statistics such as: the mean and its standard error, was introduced. (M.J.C.)

  5. Corrosion Resistance of Plasma Sprayed Ceramic CompositeCoatings on Q235 Substrate

    2001-01-01

    The corrosion resistance of SiO2/Al2O3, TiO2/Al2O3 and (SiO2+TiO2)/Al2O3 ceramic composite coatings on Q235 substrate fabricated by means of plasma spraying was investigated. The results show that Al2O3+13 wt pct TiO2 ceramic coating has the highest density, the lowest connected porosity and the best corrosion resistance. The corrosion mechanism of Q235 with ceramic coating has also been studied.

  6. Analysis of the 235U neutron cross sections in the resolved resonance range

    Using recent high-resolution measurements of the neutron transmission of 235U and the spin-separated fission cross-section data of Moore et al., a multilevel analysis of the 235U neutron cross sections was performed up to 300 eV. The Dyson Metha Δ3 statistics were used to help locate small levels above 100 eV where resonances are not clearly resolved even in the best resolution measurements available. The statistical properties of the resonance parameters are discussed

  7. Analysis of the 235U neutron cross sections in the resolved resonance range

    Using recent high-resolution measurements of the neutron transmission of 235U and the spin-separated fission cross-section data of Moore et al., a multilevel analysis of the 235U neutron cross sections was performed up to 300 eV. The Dyson Metha Δ3 statistics were used to help locate small levels above 100 eV where resonances are not clearly resolved even in the best resolution measurements available. The statistical properties of the resonance parameters are discussed. 13 refs., 8 figs., 1 tab

  8. Total kinetic energy release in the fast neutron-induced fission of $^{235}$U

    Yanez, R; Loveland, W.; King, J.; Barrett, J. S.; Fotiades, N.; Lee, H. Y.

    2015-01-01

    We have measured the total kinetic energy (TKE) release for the $^{235}$U(n,f) reaction for $E_{n}$=2-100 MeV using the 2E method with an array of Si PIN diode detectors. The neutron energies were determined by time of flight measurements using the white spectrum neutron beam at the LANSCE facility. (To calibrate the apparatus, the TKE release for $^{235}$U(n$_{th}$,f) was also measured using a thermal neutron beam from the OSU TRIGA reactor). The TKE decreases non-linearly from 169.0 MeV to ...

  9. Total kinetic energy release in the fast neutron-induced fission of $^{235}$U

    Yanez, R; Loveland, W.; King, J.; Barrett, J. S.; Fotiades, N.; Lee, H. Y.

    2016-01-01

    We have measured the total kinetic energy (TKE) release for the $^{235}$U(n,f) reaction for $E_{n}$=2-100 MeV using the 2E method with an array of Si PIN diode detectors. The neutron energies were determined by time of flight measurements using the white spectrum neutron beam at the LANSCE facility. To benchmark the TKE measurement, the TKE release for $^{235}$U(n$_{th}$,f) was also measured using a thermal neutron beam from the Oregon State University TRIGA reactor, giving pre-neutron emissi...

  10. 50 CFR 23.5 - How are the terms used in these regulations defined?

    2010-10-01

    ... participate in or support a recovery activity for that species in cooperation with one or more of the species... ENDANGERED SPECIES OF WILD FAUNA AND FLORA (CITES) Introduction § 23.5 How are the terms used in these... context otherwise requires, in this part: Affected by trade means that either a species is known to be...

  11. Relationship of blood pressure variability and angiotensinogen T235M polymorphism with Binswanger’s disease

    位慧芳

    2013-01-01

    Objective To detect the relationship of blood pressure variability(BPV) and angiotensinogen(AGT) T235M polymorphism with Binswanger’s disease(BD). Methods Totally 122 cases with BD and 108 cases with essential hypertension had been enrolled. Ambulatory blood pressure monitoring was used to get the data

  12. Verification of 235U mass content in nuclear fuel plates by an absolute method

    Nuclear Safeguards is referred to a verification System by which a State can control all nuclear materials (NM) and nuclear activities under its authority. An effective and efficient Safeguards System must include a system of measurements with capabilities sufficient to verify such NM. Measurements of NM using absolute methods could eliminate the dependency on NM Standards, which are necessary for other relative or semi-absolute methods. In this work, an absolute method has been investigated to verify the 235U mass content in nuclear fuel plates of Material Testing Reactor (MTR) type. The most intense gamma-ray signature at 185.7 keV emitted after α-decay of the 235U nuclei was employed in the method. The measuring system (an HPGe-spectrometer) was mathematically calibrated for efficiency using the general Monte Carlo transport code MCNP-4B. The calibration results and the measured net count rate were used to estimate the 235U mass content in fuel plates at different detector-to-fuel plate distances. Two sets of fuel plates, containing natural and low enriched uranium, were measured at the Fuel Fabrication Facility. Average accuracies for the estimated 235U masses of about 2.62% and 0.3% are obtained for the fuel plates containing natural and low enriched uranium; respectively, with a precision of about 3%

  13. ASSOCIATION OF ANGIOTENSINOGEN GENE M235T VARIANT IN PRE-ECLAMPSIA

    Pre-eclampsia (PE) is multisystem and multifactorial complication of pregnancy. The precise cause of pre-eclampsia has not been determined but mal adoption of the rennin and angiotensinogen (AGT) system may play a role. The products of genes involving the components of this system may be potential candidates for pre-eclampsia and hypertension related to pregnancy. This study was designed to determine whether the M235T variants of AGT gene were associated with the prevalence of pre-eclampsia and also to evaluate the role of plasma AGT in the development of the disease. Hence, developed, rapid and reliable PCR based assay was used to screen individuals for the M235T alleles. This assay was also used to genotype prospectively both recruited pregnant women with pre-eclampsia (n=24) and controls (n=11). Plasma AGT was determined by radioimmunoassay (RIA). The results of the PCR based assay revealed a significant association of 235T allele with the prevalence of all pre-eclamptic patients, Chi-square (x2) = 3.714, P0.05). Also, pre-eclamptic women exhibited significant higher levels of plasma AGT (52.15 ± 1.63) versus controls (44.76 ± 4.6) with P value < 0.001. This gave clear evidence that T235T allele and plasma AGT contributed to the development of pre-eclampsia with pregnancy and correlated with severity of the disease

  14. 19 CFR 10.235 - Filing of claim for preferential tariff treatment.

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Filing of claim for preferential tariff treatment... Trade Partnership Act § 10.235 Filing of claim for preferential tariff treatment. (a) Declaration. In connection with a claim for preferential tariff treatment for an article described in § 10.233(a)(1)...

  15. An ideal cascade for uranium 235 enrichment by centrifuge jet nozzle process

    The design of an ideal cascade for the process of isotope separation by centrifugation for the U235 enrichment, is presented. A selection of building materials used in fabrication of isotope separation plants, showing the importance of aluminium, due the bauxite mines in Northern Brazil, is done. (M.C.K.)

  16. Calculation of Prompt Fission Neutron Spectra for ~(235)U (n,f)

    2011-01-01

    The prompt fission neutron spectra for neutron-induced fission of 235U at En<5 MeV are calculated using the nuclear evaporation theory with a semi-empirical model, in which the non-constant temperature and the constant temperature related to the Fermi gas model

  17. Quantification of 235 U and 226 Ra in soil samples by means of Gamma spectroscopy

    In this work it is presented the Gamma Spectroscopy method which is realized in the Environmental Radiological Surveillance Laboratory using the option of deconvolution of a commercial software for the quantification of 235 U and 226 Ra; also is presented the method for the 226 Ra correction activity. (Author)

  18. Determination of 235U isotope abundance by difference method of fission yield

    Background: Determination of the uranium isotope abundance ratio of fuel pins is a significant stage for the quality control in safe operations of reactor. Purpose: The aim is to establish a method to examine the 235U abundance of fuel rod with fast neutron as an excitation source. Methods: Taking the fission-yield ratios of Y-bar88Rb/Y-bar104Tc and Y-bar92Sr/Y-bar104Tc as the subjects of research, the relation curves between the average yield ratios and the 235U isotopic abundance as well as the expressions Y-bar1/Y-bar2=f(H0), in which the average yield ratio (Y-bari/Y-barj ) is a function of the 235U isotopic abundance (H0), were obtained and presented based on the previous studies. Results: In order to testify the accuracy of the method, the simulation sample of 72.2% is measured by working curve, and RSD is less than 2%. Within the limit of error, the results of sample analysis are in correspondence with those of passive gamma ray method. Conclusion: All of these results indicate that the method is feasible to determine the 235U abundance of fuel rod. (authors)

  19. MGAU: A new analysis code for measuring {sup 235}U enrichments in arbitrary samples

    Gunnink, R.; Ruhter, W.D.; Miller, P. [Lawrence Livermore National Lab., CA (United States); Goerten, J.; Swinhoe, M.; Wagner, H. [Commission of the European Communities, Luxembourg (Luxembourg). Safeguards Directorate; Verplancke, J. [Canberra Applied Systems Europe, Zellik (Belgium); Bickel, M.; Abousahl, S. [Inst. for Reference Materials and Measurements, Geel (Belgium)

    1994-01-14

    We have developed a computerized analysis method for determining {sup 235}U enrichment in uranium items where no suitable reference standards exist or where nonreproducible conditions make calibration impossible. The method requires no calibrations and is capable of accuracies of 1--2% in only a few minutes.

  20. MGAU: A new analysis code for measuring 235U enrichments in arbitrary samples

    We have developed a computerized analysis method for determining 235U enrichment in uranium items where no suitable reference standards exist or where nonreproducible conditions make calibration impossible. The method requires no calibrations and is capable of accuracies of 1--2% in only a few minutes

  1. 33 CFR 183.235 - Level flotation test without weights for persons capacity.

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Level flotation test without..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower Tests § 183.235 Level...

  2. 40 CFR 266.235 - What waste treatment does the storage and treatment conditional exemption allow?

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false What waste treatment does the storage... HAZARDOUS WASTES AND SPECIFIC TYPES OF HAZARDOUS WASTE MANAGEMENT FACILITIES Conditional Exemption for Low-Level Mixed Waste Storage, Treatment, Transportation and Disposal. Treatment § 266.235 What...

  3. Application of double nuclear system concept for description of mass distribution of the 235U+n fission products

    A total mass distribution of the 235U+n nuclei fission fragments on the all mass (charge) range is obtained. The calculation data have good agreement with the experimental results that confirms the correct choice of theoretical model and concept of the nuclear complex formation (double nuclear system) like an intermediate system for description of the 235U+n fission processes

  4. 78 FR 68813 - Foreign-Trade Zone 235-Lakewood, New Jersey Application for Reorganization/Expansion Under...

    2013-11-15

    ... (Board Order 1008, 63 FR 67854, 12/09/98) and expanded on November 20, 2008 (Board Order 1589, 73 FR... Foreign-Trade Zones Board Foreign-Trade Zone 235--Lakewood, New Jersey Application for Reorganization...) Board by the Township of Lakewood, New Jersey, grantee of FTZ 235, requesting authority to...

  5. 29 CFR 2.35 - Effect of DOL support on Title VII employment nondiscrimination requirements and on other...

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Effect of DOL support on Title VII employment nondiscrimination requirements and on other existing statutes. 2.35 Section 2.35 Labor Office of the Secretary of... Effect of DOL support on Title VII employment nondiscrimination requirements and on other...

  6. Effects of NVP-BEZ235 on the proliferation, migration, apoptosis and autophagy in HT-29 human colorectal adenocarcinoma cells.

    Yu, Yang; Yu, Xiaofeng; Ma, Jianxia; Tong, Yili; Yao, Jianfeng

    2016-07-01

    The phosphoinositide 3 kinase (PI3K)/Akt/mammalian target of the rapamycin (mTOR) pathway plays a significant role in colorectal adenocarcinoma. NVP-BEZ235 (dactolisib) is a novel dual inhibitor of PI3K/mTOR. The effects of NVP-BEZ235 in human colorectal adenocarcinoma are still unclear. In the present study, we aimed to explore the proliferation, migration, apoptosis and autophagy in HT-29 human colorectal adenocarcinoma cells. HT-29 human colorectal adenocarcinoma cells were treated with NVP-BEZ235 (0, 0.001, 0.01, 0.1, 1 and 3 µM) for 24 and 48 h, respectively. Cells were also treated with NVP-BEZ235 (0.1 µM), DDP (100, 300 and 1,000 µM), and NVP-BEZ235 (0.1 µM) combined with DDP (100, 300 and 1,000 µM) respectively, and cultured for 24 h after treatment. MTT assay was utilized to evaluate the effects of NVP-BEZ235 alone or NVP-BEZ235 combined with cis-diamminedichloroplatinum (DDP) on proliferation of HT-29 cells. Cell wound-scratch assay was used detect cell migration. In addition, expression of microtubule-associated proteins 1A/1B light chain 3B (MAP1LC3B and LC3B) in HT-29 cells was detected by immunofluorescence at 48 h after NVP-BEZ235 (1 µM) treatment. Expression of proteins involved in cell cycle and proliferation (p-Akt, p-mTOR and cyclin D1), apoptosis (cleaved caspase-3), and autophagy (cleaved LC3B and Beclin-1) were detected by western blot analysis. NVP-BEZ235 inhibited the proliferation and migration of HT-29 human colorectal adenocarcinoma cells. NVP-BEZ235 decreased protein expression of p-Akt, p-mTOR and cyclin D1, and increased protein expression of cleaved caspase-3, cleaved LC3B and Beclin-1 as the concentrations and the incubation time of NVP-BEZ235 increased. In addition, NVP-BEZ235 and DDP had synergic effects in inhibiting cell proliferation and migration. The expression of protein involved in apoptosis (cleaved caspase-3) was higher in drug combination group compared to the NVP-BEZ235 single treatment group. NVP-BEZ235

  7. Electron microscopic and agarose gel electrophoretic studies on apoptosis in immune cells induced by enriched 235U

    At present, the apoptosis in Molt-4 cell (a human acute lymphoblastic leukemia cell line) and Ana-1 cell (a macrophage cell line) were studied after internal irradiation with enriched 235U. The cumulative radiation absorption dose of 235U in cultural cells through different periods were estimated. The morphological changes, which observed by electron microscopy, indicated that Molt-4 and Ana-1 immune cells after incubation with 235U, displayed nuclear fragmentation, margination of condensed chromatin, as well as the membrane-bounded apoptotic bodies formation. The agarose gel electrophoretic observations showed the DNA ladder pattern formation in Molt-4 cell as well as in Ana-1 cell. The experimental results showed that apoptosis induced by 235U in immune cells, were dependent on the 235U-treated time and cumulative radiation absorption dose

  8. A comparison of pitting susceptibility of Q235 and HRB335 carbon steels used for reinforced concrete

    GUOLIANG ZHAN

    2013-02-01

    Full Text Available The phase structure and the pitting susceptibility of two carbon steels, Q235 and HRB335, used for reinforced concrete, are investigated by phase observation, polarization curve measure-ments, electrochemical impedance spectroscopy, and Mott-Schottky analysis. It is found that Q235 is ferrite and HRB335 is pearlite. Q235 is more susceptible to chloride ions leading to pit-ting than HRB335. The polarization curves show that the breakdown potential of the passive film in saturated Ca(OH2 solution containing 0.4 M NaCl is 0 V for Q235 and 0.34 V for HRB335. The Mott-Schottky analyses show that passive films formed on Q235 and HRB335 in saturated Ca(OH2 solution containing chloride ions behave like an n-type semiconductor. The passive film formed on Q235 has a higher donor density, which explains why Q235 is more susceptible to pitting than HRB335.

  9. Simultaneous evaluation for (n,f) cross section of 235U, 239Pu, 238U and (n,γ) cross sections of 238U

    The fission cross sections for 235U, 238U, 239Pu, the capture cross sections for 238U and the ratios for 239Pu(n,f)/235U(n,f), 238U(m,f)/235U(n,f), 238U(n,γ)/235U(n,f) were firstly evaluated respectively. The experimental data were collected, analysed, selected and corrected. The data were fitted with spline fit program

  10. Accurate determination of the 235U isotope abundance by gamma spectrometry

    The purpose of this manual is to serve as guide in applications of the Certified Reference Material EC-NRM-171/NBS-SRM-969 for accurate U-235 isotope abundance measurements on bulk uranium samples by means of gamma spectrometry. The manual provides a thorough description of this non-destructive assay technique. Crucial measurement parameters affecting the accuracy of the gamma-spectrometric U-235 isotope abundance determination are discussed in detail and, whereever possible, evaluated quantitatively. The correction terms and tolerance limits given refer both to physical and chemical properties of the samples under assay and to relevant parameters of typical measurement systems such as counting geometry, signal processing, data evaluation and calibration. (orig.)

  11. Candidate processes for diluting the 235U isotope in weapons-capable highly enriched uranium

    The United States Department of Energy (DOE) is evaluating options for rendering its surplus inventories of highly enriched uranium (HEU) incapable of being used to produce nuclear weapons. Weapons-capable HEU was earlier produced by enriching uranium in the fissile 235U isotope from its natural occurring 0.71 percent isotopic concentration to at least 20 percent isotopic concentration. Now, by diluting its concentration of the fissile 235U isotope in a uranium blending process, the weapons capability of HEU can be eliminated in a manner that is reversible only through isotope enrichment, and therefore, highly resistant to proliferation. To the extent that can be economically and technically justified, the down-blended uranium product will be made suitable for use as commercial reactor fuel. Such down-blended uranium product can also be disposed of as waste if chemical or isotopic impurities preclude its use as reactor fuel

  12. Chromosome aberrations induced in human lymphocytes by U-235 fission neutrons. Pt. 2

    Blood samples were spiked with Na-24 to study the separate effect of this nuclide on the incidence of chromosomal aberrations in neutron irradiated blood samples. A delay of 96 h was allowed before cultivation, so the results of chromosomal aberration analysis could be compared with the results obtained by direct irradiation of blood samples with U-235 fission neutrons. The absorbed dose was calculated using a simple conservative model. From the results obtained we can conclude that Na-24 alone was not the reason for the difference in the incidence of chromosomal aberrations between blood samples cultivated immediately after 'in vitro' irradiation by U-235 fission neutrons and samples which were cultivated after 96 h storage. (orig.)

  13. Fuel cycle cost comparison of choices in U-235 recycle in the HTGR

    An analysis of alternative options for the recycle of discharged makeup U-235 (''residual'' makeup) in HTGRs shows that the three-particle system which has been the reference plan remains optimal. This result considers both the resource utilization and the handling costs attendant to the alternative strategies (primarily in the recycle facility and in waste disposal). Furthermore, this result appears to be true under all forseeable economic conditions. A simple risk assessment indicates that recycle cost (including reprocessing, refabrication, and related waste disposal) would have to double or triple in order for the alternative U-235 recycle schemes to become attractive. This induces some degree of confidence in the choice of staying with the reference cycle in spite of the large degree of uncertainty over recycle and its costs

  14. The 235U Prompt Fission Neutron Spectrum in the BR1 Reactor at SCK•CEN

    Wagemans, Jan; Malambu, Edouard; Borms, Luc; Fiorito, Luca

    2016-02-01

    The BR1 research reactor at SCK•CEN has a spherical cavity in the graphite above the reactor core. In this cavity an accurately characterised Maxwellian thermal neutron field is present. Different converters can be loaded in the cavity in order to obtain other types of neutron (and gamma) irradiation fields. Inside the so-called MARK III converter a fast 235U(n,f) prompt fission neutron field can be obtained. With the support of MCNP calculations, irradiations in MARK III can be directly related to the pure 235U(n,f) prompt fission neutron spectrum. For this purpose MARK III spectrum averaged cross sections for the most relevant fluence dosimetry reactions have been determined. A calibration factor for absolute measurements has been determined applying activation dosimetry following ISO/IEC 17025 standards.

  15. Active Neutron Interrogation and Delayed Neutron Counting (AIDNEC) for assay of 235U

    A method has been developed for non destructive assay of 235U using active neutron interrogation followed by delayed neutron counting (AIDNEC) system. The neutrons from a plasma focus (PF) device were used to bombard the samples containing low enriched uranium ranging from 13 mg to 5 g. The PF device generates (1.2±0.3) x109 D-D fusion neutrons per shot with a pulse width of 46±5 ns. The delayed neutrons were monitored using a bank of six 3He detectors. The sensitivity of the system was found to be about 1000 cps per gram over the accumulation time of 25 seconds per neutron pulse of ∼109. The detection limit of the system is estimated to be 18 mg of 235U. (author)

  16. Studies of Neutron-Induced Fission of 235U, 238U, and 239Pu

    Duke, Dana; TKE Team

    2014-09-01

    A Frisch-gridded ionization chamber and the double energy (2E) analysis method were used to study mass yield distributions and average total kinetic energy (TKE) release from neutron-induced fission of 235U, 238U, and 239Pu. Despite decades of fission research, little or no TKE data exist for high incident neutron energies. Additional average TKE information at incident neutron energies relevant to defense- and energy-related applications will provide a valuable observable for benchmarking simulations. The data can also be used as inputs in theoretical fission models. The Los Alamos Neutron Science Center-Weapons Neutron Research (LANSCE - WNR) provides a neutron beam from thermal to hundreds of MeV, well-suited for filling in the gaps in existing data and exploring fission behavior in the fast neutron region. The results of the studies on 238U, 235U, and 239Pu will be presented. LA-UR-14-24921.

  17. Determination of U-235 quantity in fresh fuel elements by neutron coincidence collar technique

    The U-235 quantity per lenght of fresh fuel assemblies of the Angra-I first recharge was determined by Neutron Coincidence Collar technique (N.C.C.). This technique is well-founded in fresh fuel assemblies activation by thermal neutrons from AmLi source to generate U-235 fission neutrons. These neutrons are detected by coincidence method in polyethylene structure where 18 He-3 detectors were placed. The coincidence counting results, in active mode (AmLi), showed 0,7% to standard deviation and equal to 1,49% to mass in 1000s of counting. The accuracies of different calibration methods were evaluated and compared. The results showed that the operator declared values are consistent. This evaluation was part of technical-exchange program between Safeguards Laboratory from C.N.E.N. and Los Alamos National Lab., United States. (author)

  18. Calculation of prompt fission neutron spectra for 235U(n,f)

    CHEN Yong-Jing; JIA Min; TAO Xi; QIAN Jing; LIU Ting-Jin; SHU Neng-Chuan

    2012-01-01

    The prompt fission neutron spectra for the neutron-induced fission of 235U at En < 5 MeV are calculated using nuclear evaporation theory with a semi-empirical model,in which the nonconstant and constant temperatures related to the Fermi gas model are taken into account. The calculated prompt fission neutron spectra reproduce the experimental data well.For the n(thermal)+235U reaction,the average nuclear temperature of the fission fragment,and the probability distribution of the nuclear temperature,are discussed and compared with the Los Alamos model.The energy carried away by γ rays emitted from each fragment is also obtained and the results are in good agreement with the existing experimental data.

  19. Statistical properties of the 235U resonance parameters up to 300 eV

    An accurate resonance analysis of the 235U neutron cross sections up to 300 eV is in progress for the ENDF/B-VI files. A detailed discussion of the data base and a description of the method of resonance analysis have been given elsewhere. The purpose of this paper is to report on the statistical properties of the 235U resonance parameters and compare our results with those of previous analyses. The statistical properties of nuclear levels are of both technical and theoretical interest. From the technical viewpoint, these properties are the basis for an extrapolation into the unresolved resonance region, which is of relevance to the calculation of effective group cross sections for reactor design. From the theoretical viewpoint, the resonance parameters obtained from a multilevel R-matrix analysis of a consistent set of neutron cross sections should satisfy a set of statistical properties arising from general properties of the nuclear Hamiltonian

  20. The 235U Prompt Fission Neutron Spectrum in the BR1 Reactor at SCK•CEN

    Wagemans Jan

    2016-01-01

    Full Text Available The BR1 research reactor at SCK•CEN has a spherical cavity in the graphite above the reactor core. In this cavity an accurately characterised Maxwellian thermal neutron field is present. Different converters can be loaded in the cavity in order to obtain other types of neutron (and gamma irradiation fields. Inside the so-called MARK III converter a fast 235U(n,f prompt fission neutron field can be obtained. With the support of MCNP calculations, irradiations in MARK III can be directly related to the pure 235U(n,f prompt fission neutron spectrum. For this purpose MARK III spectrum averaged cross sections for the most relevant fluence dosimetry reactions have been determined. A calibration factor for absolute measurements has been determined applying activation dosimetry following ISO/IEC 17025 standards.

  1. In-situ gamma-PHA measurements to support unconditional release of 235-F chiller units

    The Analytical Development Section of Savannah River Technology Center (SRTC) was requested by the Facility Decommission Division (FDD) to conduct in-situ gamma-ray pulse height analysis measurements to support the unconditional release of 235-F chiller units. The chiller units were used to cool process water in the 235-F facility. The measurements' main goal is to confirm that there is no process-related contaminants present on the chillers. For each of the two F-area clean water chillers, the authors have acquired ten gamma-ray pulse height analysis spectra. This report will discuss the purpose of the measurements, the experimental setup, data acquisition, calculations and results, and a conclusion of the study

  2. Evaluation of the fission cross sections for U-233 and U-235

    Activities of evaluation of nuclear data was started in Japan, 1963, and the results were published as JENDL-1., JENDL-2 and JENDL-3.1. The revised edition, JENDL-3.2 is now under preparation. The evaluation works of the fission cross sections for U-233 and U-235 and the encountered problems are discussed. For the 1 to 7 MeV region of U-233 cross section, the data by Poenitz adopted in JENDL-2 were discarded and finally ratio data by the Tohoku University were adopted in JENDL-3. The resolved resonance parameters for heavy nuclides including U-233 and U-235 are treated with the Reich-Moore formula in JENDL-3.2 instead of the previously used Breit and Wigner formula. (T.H.)

  3. Yields of Gamma- and X-Ray Radiation of Alpha-Decays of 235U

    Precise knowledge of gamma- and X-rays emission probabilities of uranium isotopes is vital for accurate gamma-spectrometric determination of the isotopic composition and quantity of uranium. The peak intensity ratio methods employing high resolution gammaspectrometry and intrinsic efficiency calibration approach are known to provide most accurate and reliable isotopic information. When applied to unshielded and moderately shielded material, these methods largely benefit from de-convolution of the 90-100 keV narrow spectral interval, which contains intense gamma- and X-ray lines of major uranium isotopes 235U and 238U. These are the 92.37 keV and 92.79 keV gamma-rays of 238U/234Th, and the 93.35 keV ThKα1 X-rays from alpha-decay of 235U. Although the emission probability ratios of these lines were accurately established, their absolute yields are still lacking accuracy. For instance, as resulted from recent study, the yields of 234Th lines become corrected by 30%, compared with their previous values. This consequently raised a question regarding validity of the yield data for the 93.35 keV line of 235U and triggered the present experimental study. This study was later extended to the reexamination of emission probabilities of other 235U gamma-lines with energies above 205 keV. The experimental data used in the current work was collected using SRM 969 and CRM 146 reference uranium samples. (author)

  4. Effect of laser cutting parameters on surface quality of low carbon steel (S235)

    I. Miraoui; M. Boujelbene; D. Katundi; E. Bayraktar; M. Zaied

    2012-01-01

    Purpose: This work analysis surface roughness parameters as a function of Laser power and cutting speed. The surface roughness parameters are determined after statistical analysis (ANOVA) and propose a simple mathematical model.Design/methodology/approach: Machining were carried out by Laser cutting (CO2) of sheet metal (low carbon steel, S235) produces different surface quality. The statistical processing of the experimental results enabled development of a mathematical model to calculate th...

  5. Investigating Prompt Fission Neutron Emission from 235U(n,f) in the Resolved Resonance Region

    Göök Alf; Hambsch Franz-Josef; Oberstedt Stephan

    2016-01-01

    Investigations of prompt emission in fission is of importance in understanding the fission process in general and the sharing of excitation energy among the fission fragments in particular. Experimental activities at IRMM on prompt neutron emission from fission in response to OECD/NEA nuclear data requests is presented in this contribution. Main focus lies on currently on-going investigations of prompt neutron emission from the reaction 235U(n,f) in the region of the resolved resonances. For ...

  6. Measurement of 235U fission reaction-rates in combined device

    Fission reaction-rates of 235U (wrapped with Cd of 0.8 mm) in the combined setup were measured, using the enriched uranium fission chamber and capturing detector. The method of detecting the low-energy scattering, neutron background was studied. The experimental error is ±6.0%-±10.2%. The results was compared with the ones of 238U the fission reaction-rates. (authors)

  7. Criticality study of the storage of radioactive waste containing 235U

    The purpose of this study is to define the conditions of storage of nuclear waste drums containing 350 g of 235U (per drum). This study is valid for a square pitch stacking of cylindrical drums whose height/diameter ratio does not exceed 3. The reflector effect of concrete is taken into account. This study defines a conservative case that can be used under any hypothesis of moderation, of radiation coupling between drums and of fissile material density. (A.C.)

  8. Statistical properties of the S-wave resonances of {sup 235}U

    Leal, L.C.; Derrien, H.; Larson, N.M.

    1997-06-01

    The resonance parameters of {sup 235}U in the energy range 0 eV to 2.25 keV were obtained from a generalized least squares analysis of a large set of experimental data using the Reich-Moore formalism in the fitting code SAMMY. The aim of the present paper is to present the statistical properties of the s-wave resonance parameters generated from this study.

  9. A Fast Test for Excessive U235 Concentrations in Enriched Fuel Elements

    This paper describes a new non-destructive method of detecting areas of enriched fuel elements containing excessive U235 , and an instrument designed to inspect uranium-aluminium alloy fuel for the NRU reactor using the new method. The new method is as precise as conventional methods but is m u c h faster. The improvement in test speed depends on the application, but typically m a y be a factor of four. Alternatively, the method m a y be used to improve the precision of the test without increasing the testing time. The method may be used when the U235 concentration in selected areas of a fuel element is estimated by measuring the intensity of 184-keV γ-rays (from the natural decay of U235 ) and when an area is considered acceptable if the measured intensity from it is less than a limiting intensity equivalent to the maximum allowable concentration. It the measured intensity is much less or much greater than the limiting intensity, much less time is required to make this decision than when they are nearly the same. The new method takes advantage of this. It thus inspects each area only as long as is necessary to make a decision with the required confidence. The average time taken in practical cases is less than that taken by conventional methods which inspect each area for a pre-selected time chosen to give the required confidence in the most difficult cases - when the measured and limiting intensities are nearly the same. The new method is based on sequential sampling theory. It may also be used to detect areas with undesirably low U235 concentration. (author)

  10. Measurements of delayed neutron parameters for U-235 and Np-237

    Loaiza, D.

    1997-07-01

    Delayed neutrons are emitted by excited nuclei formed in beta decay of fission products called delayed neutron precursors. About 1% of the total neutrons released in fission are delayed neutrons; however, this small fraction plays an important role in nuclear reactor control. The delayed neutrons determine the time-dependent behavior of reactors, and knowledge of parameters used to predict neutron emission rate is essential for establishing reactivity worths. The delayed neutron yields, decay constants, and the absolute yield for the six-group delayed neutrons have been measured for U-235 and Np-237. This experiment has been called for in the forecast of experiments needed to support operations in the US. The bare U-235 metal assembly Godiva IV at the Los Alamos Critical Experiment Facility (LACEF) provided the source of neutrons. Godiva IV generated about 10{sup 7} total fissions in the samples for the infinite and instantaneous irradiation needed to accentuate the shorter and longer-lived groups of delayed neutrons. The detection system used in the experiment consisted of 20 He-3 tubes embedded in a polyethylene cylinder. The delayed neutron activity resulting from the fast neutron-induced fission has been measured. The measured absolute yield for U-235 was determined to be 0.0163 {+-} 0.009 neutrons/fission. This value compares very well with the well-established Keepin absolute yield of 0.0165 {+-} 0.0005. The newly measured absolute yield value for Np-237 was 0.0126 {+-} 0.0007, which compares well to the recently reported value of 0.0129 {+-} 0.0004 by Saleh and Parish. The measured values for U-235 are corroborated with period (e-folding time) versus reactivity calculations.

  11. Uranium content and 235U/238U isotopic ratio in dental porcelain powders determined by neutron activation analysis

    The uranium contents and 235U/238U isotopic ratios in 48 dental porcelain powders of 8 brands marketed in Japan were determined by non-destructive neutron activation analysis. The photopeak counts of 277.6 keV of 239Np formed by the 238U(n,γ)239U (yield to)239Np + β- reaction and at 1.595.2 keV of 140La produced by 235U fission were measured with a Ge(Li) semiconductor detector system to determine the uranium content and 235U/238U isotopic ratio. The results of the analysis are tabulated and their significance discussed. (author)

  12. Calculation of resonance self-shielding for 235U from 0 to 2250 eV

    Over the years, the evaluated 235U cross sections in the resolved energy range have been extensively revised. A major accomplishment was the first evaluation released to the ENDF/B-VI library. In that evaluation, the low energy range bound was lowered to 10-5 eV, and the upper limit raised to 2,250 eV. Several high-resolution measurements in conjunction with the Bayesian computer code SAMMY were used to perform the analysis of the 235U resonance parameters. SAMMY uses the Reich-Moore formalism, which is adequate for representing neutron cross sections of fissile isotopes, and a generalized least-squares (Bayes) technique for determining the energy-dependence of the neutron cross sections. Recently a re-evaluation of the 235U cross section in the resolved resonance region was completed. This evaluation has undergone integral tests in various laboratories throughout the USA and abroad. The evaluation has been accepted for inclusion in ENDF/B-VI release 5. The intent of this work is to present results of calculations of self-shielded fission rates carried out with these resonance parameters and to compare those fission rates with experimental data. Results of this comparison study provide an assessment of the resonance parameters with respect to the calculation of self-shielded group cross sections

  13. Total kinetic energy release in the fast neutron-induced fission of $^{235}$U

    Yanez, R; King, J; Barrett, J S; Fotiades, N; Lee, H Y

    2016-01-01

    We have measured the total kinetic energy (TKE) release for the $^{235}$U(n,f) reaction for $E_{n}$=2-100 MeV using the 2E method with an array of Si PIN diode detectors. The neutron energies were determined by time of flight measurements using the white spectrum neutron beam at the LANSCE facility. To benchmark the TKE measurement, the TKE release for $^{235}$U(n$_{th}$,f) was also measured using a thermal neutron beam from the Oregon State University TRIGA reactor, giving pre-neutron emission $E^*_{TKE}=170.7\\pm0.4$ MeV in good agreement with known values. Our measurements are thus absolute measurements. The TKE in $^{235}$U(n,f) decreases non-linearly from 169.0 MeV to 161.4 MeV for $E_{n}$=2-90 MeV. Comparison of the data with the multi-modal fission model of Brosa indicates the TKE decrease is a consequence of the growth of symmetric fission and the corresponding decrease of asymmetric fission with increasing neutron energy. The average TKE associated with the Brosa superlong, standard I and standard II ...

  14. Fission fragment mass and angular distribution in 6,7Li+235,238U reactions

    Fission fragment (FF) angular distributions for 6,7Li+235,238U reactions and mass distributions for 6,7Li+ 238U reactions have been measured at energies near and above the Coulomb barrier. The angle integrated fission cross sections for 6Li induced reactions at sub-barrier energies are found to be higher than 7Li induced reactions possibly due to larger contribution of breakup induced fission in case of the former compared to the latter. The FF anisotropy for 6,7Li+235U was found to be smaller than 6,7Li+238U, manifesting the effect of target ground state spin. The statistical saddle point (SSP) model predictions were found to be consistent with the measured FF anisotropy for 6,7Li+235U, however they were under-estimated for 6,7Li+238U particularly at lower energies. Observation of larger FWHM of FF folding angle distribution and sharp increase in peak to valley ratio for FF mass distribution with the decrease in bombarding energy in 6,7Li+238U reactions confirms the presence of breakup induced fission. (authors)

  15. Fission fragment mass and angular distribution in 6,7Li+235,238U reactions

    Santra S.

    2013-12-01

    Full Text Available Fission fragment (FF angular distributions for 6,7Li+235,238U reactions and mass distributions for 6,7Li+238U reactions have been measured at energies near and above the Coulomb barrier. The angle integrated fission cross sections for 6Li induced reactions at sub-barrier energies are found to be higher than 7Li induced reactions possibly due to larger contribution of breakup induced fission in case of the former compared to the latter. The FF anisotropy for 6,7Li+235U was found to be smaller than 6,7Li+238U, manifesting the effect of target ground state spin. The statistical saddle point (SSP model predictions were found to be consistent with the measured FF anisotropy for 6,7Li+235U, however they were under-estimated for 6,7Li+238U particularly at lower energies. Observation of larger FWHM of FF folding angle distribution and sharp increase in peak to valley ratio for FF mass distribution with the decrease in bombarding energy in 6,7Li+238U reactions confirms the presence of breakup induced fission.

  16. Isotope fractionation of 238U and 235U during biologically-mediated uranium reduction

    Stirling, Claudine H.; Andersen, Morten B.; Warthmann, Rolf; Halliday, Alex N.

    2015-08-01

    A series of laboratory-controlled microbial experiments using gram-negative sulphate-reducing bacteria (Desulfovibrio brasiliensis) inoculated with natural uranium were performed to investigate 238U/235U fractionation during bacterially-mediated U reduction. Control experiments, without bacteria to drive U reduction, were conducted in parallel. Paired measurements of 238U/235U and U concentration for both the residual growth medium solution and the accumulated biologically-mediated precipitate were obtained using multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS). The control experiments show that only minor (similar α values. Competing processes such as U co-precipitation (e.g. adsorption) may act to lower the apparent value for α and possibly play a secondary role both in the microbial experiments of this study and in natural U reduction settings where variable α values are found. These results may suggest that microbes adept at inducing U(VI) reduction play a crucial role in facilitating significant 238U/235U isotope fractionation in nature.

  17. Resonance analysis and evaluation of the 235U neutron induced cross sections

    Neutron cross sections of fissile nuclei are of considerable interest for the understanding of parameters such as resonance absorption, resonance escape probability, resonance self-shielding,and the dependence of the reactivity on temperature. In the present study, new techniques for the evaluation of the 235U neutron cross sections are described. The Reich-Moore formalism of the Bayesian computer code SAMMY was used to perform consistent R-matrix multilevel analyses of the selected neutron cross-section data. The Δ3-statistics of Dyson and Mehta, along with high-resolution data and the spin-separated fission cross-section data, have provided the possibility of developing a new methodology for the analysis and evaluation of neutron-nucleus cross sections. The results of the analysis consists of a set of resonance parameters which describe the 235U neutron cross sections up to 500 eV. The set of resonance parameters obtained through a R-matrix analysis are expected to satisfy statistical properties which lead to information on the nuclear structure. The resonance parameters were tested and showed good agreement with the theory. It is expected that the parametrization of the 235U neutron cross sections obtained in this dissertation represents the current state of art in data as well as in theory and, therefore, can be of direct use in reactor calculations. 44 refs., 21 figs., 8 tabs

  18. Activation Doppler Measurements on U 238 and U 235 in Some Fast Reactor Spectra

    Measurements of the Doppler effect in U-238 capture and U-235 fission have been made by means of the activation technique in three different neutron spectra in the fast critical assembly FR0. The experiments involved the irradiation of thin uranium metal foils or oxide disks, which were heated in a small oven located at the core centre. The measurements on U-238 were extended to 1780 deg K and on U-235 to 1470 deg K. A core region surrounding the oven was homogenized in order to facilitate the interpretation of results. The reaction rates in the uranium samples were detected by gamma counting. The experimental method was checked with regard to systematic errors by irradiations in a thermal spectrum. The data obtained for U-238 capture were corrected for the effect of neutron collisions in the oven wall, and were extrapolated to zero sample thickness. In the softest spectrum (core 5) a Doppler effect (relative increase in capture rate) of 0.260 ± 0.018 was obtained on heating from 343 to 1780 deg K, and in the hardest spectrum (core 3) the corresponding value was 0.030 ± 0.003. An appreciable Doppler effect in U-235 fission was obtained only in the softest spectrum, in which the measured increase in fission rate on heating from 320 to 1470 deg K was 0.007 ± 0.003

  19. New signposts of massive star formation in the S235A-B region

    Felli, M; Massi, F; Robberto, M; Cesaroni, Riccardo; Felli, Marcello; Massi, Fabrizio; Robberto, Massimo

    2006-01-01

    We report on new aspects of the star-forming region S235AB revealed through high-resolution observations at radio and mid-infrared wavelengths. Using the Very Large Array, we carried out sensitive observations of S235AB in the cm continuum (6, 3.6, 1.3, and 0.7) and in the 22 GHz water maser line. These were complemented with Spitzer Space Telescope Infrared Array Camera archive data to clarify the correspondence between radio and IR sources. We made also use of newly presented data from the Medicina water maser patrol, started in 1987, to study the variability of the water masers found in the region. S235A is a classical HII region whose structure is now well resolved. To the south, no radio continuum emission is detected either from the compact molecular core or from the jet-like structure observed at 3.3 mm, suggesting emission from dust in both cases. We find two new compact radio continuum sources (VLA-1 and VLA-2) and three separate maser spots. VLA-1 coincides with one of the maser spots and with a pre...

  20. Molecular jet emission and a spectroscopic survey of S235AB

    Burns, R A; Hirota, T; Motogi, K; Imai, I; Omodaka, T

    2016-01-01

    Context. The S235AB star forming region houses a massive young stellar object which has recently been reported to exhibit possible evidence of jet rotation - an illusive yet crucial component of disk aided star formation theories. Aims. To confirm the presence of a molecular counterpart to the jet and to further study the molecular environment in in S235AB. Methods. We search for velocity wings in the line emission of thermal SiO (J=2-1, v=0), a tracer of shocked gas, which would indicate the presence of jet activity. Utilising other lines detected in our survey we use the relative intensities of intra species transitions, isotopes and hyperfine transitions to derive opacities, temperatures, column densities and abundances of various molecular species in S235AB. Results. The SiO (J=2-1, v=0) emission exhibits velocity wing of up to 75 km/s above and below the velocity of the star, indicating the presence of a jet. The molecular environment describes an evolutionary stage resemblant of a hot molecular core.

  1. Phytic acid as a corrosion inhibitor for 235 steel in NaCl solution%植酸自组装膜对Q235钢在氯化钠溶液中的缓蚀作用

    王凤平; 胡隋军; 唐丽娜

    2014-01-01

    The corrosion inhibition of phytic acid on Q235 steel in NaCl solution was investigated by weight loss technique ,scanning electronic microscopy and the energy spectrum of X rays .The results show that inhibition efficiency of phytic acid on Q 235 steel in NaCl solution is obviously different at different pH .Phytic acid can accelerate the corrosion rate of Q 235 steel under acidic condition .But under neutral and alkaline condition ,phytic acid has excellent corrosion inhibition for 235steel in NaCl solution .Nevertheless ,the corrosion inhibition efficiency of phytic acid for Q235 steel in NaCl solu-tion increases with increasing phytic acid concentration under neutral and alkaline condition .If the concentration of phytic acid is 0 .5% ,the inhibition efficiency is more than 90% .%从植物中提取的植酸作金属缓蚀剂对环境保护具有重要意义.采用失重法、扫描电子显微镜和X射线能谱研究了植酸对Q235钢在NaCl溶液中的缓蚀行为以及影响因素.失重实验结果表明,不同p H值植酸对Q 235钢的缓蚀效果明显不同,在酸性条件下植酸加速Q235钢的腐蚀,在中性及碱性条件下,植酸对Q235钢的腐蚀具有明显的抑制作用.中性或碱性条件下,NaCl溶液中植酸对Q235钢缓蚀效率随植酸浓度的增加而增加,植酸浓度达0.5%以上时,缓蚀效率高达90%以上.扫描电镜结果表明,植酸处理后的Q235钢表面生成膜在不同pH下明显不同,碱性条件下的生成膜明显好于酸性条件下的生成膜.

  2. Isotope fractionation of 238U and 235U during biologically-mediated uranium reduction

    Stirling, Claudine H.; Andersen, Morten B.; Warthmann, Rolf; Halliday, Alex N.

    2015-08-01

    A series of laboratory-controlled microbial experiments using gram-negative sulphate-reducing bacteria (Desulfovibrio brasiliensis) inoculated with natural uranium were performed to investigate 238U/235U fractionation during bacterially-mediated U reduction. Control experiments, without bacteria to drive U reduction, were conducted in parallel. Paired measurements of 238U/235U and U concentration for both the residual growth medium solution and the accumulated biologically-mediated precipitate were obtained using multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS). The control experiments show that only minor (<0.1‰), if any 238U/235U fractionation occurs during co-precipitation with calcite. This implies that carbonate sediments are capable of faithfully recording the signature of the global ocean during Earth's major climatic events, including oxygenation and de-oxygenation transitions in the marine environment. The results for the microbial experiments demonstrate that the 238U/235U composition of the unreacted growth medium containing U(VI) is isotopically lighter than the composition of the U(IV)-bearing precipitate as U(VI) is consumed, in agreement with field-based observations of microbially-mediated U reduction. Uranium isotopic shifts of up to 0.8‰ were observed between the liquid and solid phases. These observations can be modelled using a Rayleigh distillation approach describing kinetic uptake in a closed system, which yields a fractionation factor α of 0.99923 ± 0.00004 (ε = -0.77 ± 04‰) for U(VI)-U(IV) reduction mediated by the D. brasiliensis microbe. This fractionation behaviour is consistent with that observed in field-based redox environments, which give rise to similar α values. Competing processes such as U co-precipitation (e.g. adsorption) may act to lower the apparent value for α and possibly play a secondary role both in the microbial experiments of this study and in natural U reduction settings where

  3. An R matrix analysis of the 235U neutron-induced cross sections up to 500 eV

    In this paper a detailed evaluation of the R matrix resonance parameters describing the interaction of neutrons with 235U has been performed up to 500 eV using the most recent high-resolution measurements of the 235U neutron cross sections. The availability of 235U spin-separated neutron cross-section data, in conjunction with the use of the Δ3 statistics of Metha and Dyson, has made possible a detailed study of the statistical distribution of the resonance parameters and their average values. The present R matrix resonance parameters have been converted into equivalent sets of Adler- Adler parameters and multipole momentum space expansion parameters. Extensive validation of this evaluation has been performed by comparing self-shielded fission rates computed with these R matrix parameters with the measurements of Czirr; a test of the ENDF/B unresolved resonance formalism for the calculation of 235U of self-shielding factors is also presented

  4. Study of the origin of elements of the uranium-235 family observed in excess in the vicinity of the experimental nuclear EL4 reactor under dismantling. Lessons got at this day and conclusions; Etude de l'origine des elements de la famille de l'uranium-235 observes en exces dans les environs du reacteur nucleaire experimental EL4 en cours de demantelement. Enseignements retires a ce jour et conclusion

    NONE

    2007-07-01

    This study resumes the discovery of an excess of actinium 227 found around by EL4 nuclear reactor actually in dismantling. The search for the origin of this excess revealed a real inquiry of investigation during three years. Because a nuclear reactor existed in this area a particular attention will have concerned this region. The doubt became the line of conduct to find the answer to the human or natural origin of this excess. Finally and against any evidence, it appears that the origin of this phenomenon was natural, consequence of the particular local geology. The detail of the different investigations is given: search of a possible correlation with the composition of elevations constituent of lanes, search (and underlining) of new sites in the surroundings of the Rusquec pond and the Plouenez station, study of the atmospheric deposits under winds of the nuclear power plant and in the east direction, search of a possible relationship with the gaseous effluents of the nuclear power plant in the past, historical study of radioactive effluents releases in the fifty last years by the analysis of the sedimentary deposits in the Saint-Herbiot reservoir, search of a possible correlation between the excess of actinium 227 and the nuclear power plant activity; search of a possible correlation with a human activity without any relationship with the nuclear activities, search of a correlation with the underground waters, search of a correlation with the geological context, collect of information on the possible transfers in direction of the food chain, determination of the radiological composition of the underground waters ( not perturbed by human activity), search of the cause of an excess of actinium 227 in the old channel of liquid effluents release of the nuclear power plant. The results are given and discussed. And contrary to all expectations the origin of the excess of actinium 227 is completely natural. (N.C.)

  5. Neutron inelastic-scattering cross sections of 232Th, 233U, 235U, 238U, 239Pu and 240Pu

    Differential-neutron-emission cross sections of 232Th, 233U, 235U, 238U, 239Pu and 240Pu are measured between approx. = 1.0 and 3.5 MeV with the angle and magnitude detail needed to provide angle-integrated emission cross sections to approx. 232Th, 233U, 235U and 238U inelastic-scattering values, poor agreement is observed for 240Pu, and a serious discrepancy exists in the case of 239Pu

  6. Test spectra experimental construction for evaluating gamma-spectrometry computer codes for the 235U determination

    Karfopoulos Konstantinos L.

    2014-01-01

    Full Text Available The determination of 235U in environmental samples from its 185.72 keV photons may require the deconvolution of the multiplet photopeak at ~186 keV, due to the co-existence of the 186.25 keV photons of 226Ra in the spectrum. Successful deconvolution depends on many parameters, such as the detector characteristics, the activity concentration of the 235U and 226Ra in the sample, the background continuum in the 186 keV energy region and the gamma-spectrometry computer code used. In this work two sets of experimental test spectra were constructed for examining the deconvolution of the multiplet photopeak performed by different codes. For the construction of the test spectra, a high-resolution low energy germanium detector was used. The first series consists of 140 spectra and simulates environmental samples containing various activity concentration levels of 235U and 226Ra. The second series consists of 280 spectra and has been derived by adding 137Cs, corresponding to various activity concentration levels, to specific first series test spectra. As the 137Cs backscatter edge is detected in the energy region of the multiplet photopeak at ~186 keV, this second series of test spectra tests the analysis of the multiplet photopeak in high background continuum conditions. The analysis of the test spectra is performed by two different g-spectrometry analysis codes: (a spectrum unix analysis code, a computer code developed in-house and (b analysis of germanium detector spectra, a program freely available from the IAEA. The results obtained by the two programs are compared in terms of photopeak detection and photopeak area determination.

  7. 235U fission product gamma spectra: a comparison between experiment and calculation

    Recent measurements of 235U fission product gamma spectra (ORNL), after reduction to a broad group structure, were compared with results of corresponding summation calculations which were made with the UKFPDD-1 fission product data base. In order to facilitate convenient integration of the summation results, weighted sums of decaying exponentials were accurately fitted to them using an iterative least-squares method described. The comparisons between experiment and calculation reveal significant deficiencies in data for short-lived nuclides which prevent the accurate calculation of short-term ( 5 MeV are also examined briefly and possible causes for them are discussed. (author)

  8. Critical experiments to determine amount of U-235 in research reactor fuel assemblies

    Four different critical core configurations of the IRR1 [Bettan, M., Hirshfeld H., Levine, S.H., 2002. Method to determine the burnup of the IRR1 fuel assemblies. In: Proceedings of the 21st Conference of the Nuclear Societies in Israel, p. 38-41], Cores 1, 2, 3, and 4, have been used to determine experimentally the reactivity changes caused by interchanging different fuel assemblies (FAs) in the same core position [Bettan, M., Hirshfeld H., Levine, S.H., 2002. Method to determine the burnup of the IRR1 fuel assemblies. In: Proceedings of the 21st Conference of the Nuclear Societies in Israel, p. 38-41; Levine, S.H., Kim, S.S., 1985. Development of an asymmetric multiple-position neutron source (AMPNS) method to monitor the criticality of a degraded reactor core. Ann. Nucl. Energy 12, 517; IAEA-TECDOC-633, 1992. Determination of research fuel burnup, January]. The different fuel assemblies varied in their burnup or loss in U-235 causing the core reactivity to change systematically with each FA interchange. The control blade height was altered to compensate for this change in the core reactivity to maintain the core critical. The control blade reactivity worth as a function of its height was measured by period measurements so that the reactivity change due to the interchange of an FA was determined. The WIMS/EXT2 [WIMS-D4: Winfrith Improved Multigroup Scheme (WIMS) code system, 1969. Computer Code Package CCC-576, RSICC/ORNL, Oak Ridge, TN; Fowler, T.B. et al., 1967. EXTERMINATOR-II: A FORTRAN IV Code for solving multigroup diffusion equations in two dimensions, ORNL-4078, ORNL, April] codes are used to evaluate the change in core reactivity as a function of FA U-235 or burnup. By relating the calculation of the reactivity change with the measured reactivity change, the burnup or U-235 mass in each FA is determined. The U-235 mass of the FAs gave good agreement between measurements made of the same FA in different cores and appears to bring better agreement between

  9. Neutron shielding verification measurements and simulations for a 235-MeV proton therapy center

    Newhauser, W D; Dexheimer, D; Yan, X; Nill, S

    2002-01-01

    The neutron shielding at the Massachusetts General Hospital's 235-MeV proton therapy facility was investigated with measurements, analytical calculations, and realistic three-dimensional Monte Carlo simulations. In 37 of 40 cases studied, the analytical calculations predicted higher neutron dose equivalent rates outside the shielding than the measured, typically by more than a factor of 10, and in some cases more than 100. Monte Carlo predictions of dose equivalent at three locations are, on average, 1.1 times the measured values. Except at one location, all of the analytical model predictions and Monte Carlo simulations overestimate neutron dose equivalent.

  10. Activity of HMR 3647 Compared to Those of Six Compounds against 235 Strains of Enterococcus faecalis

    Hoellman, Dianne B.; Lin, Gengrong; Jacobs, Michael R.; Appelbaum, Peter C.

    1999-01-01

    Agar dilution was used to test the activities of HMR 3647, erythromycin A, azithromycin, clarithromycin, roxithromycin, clindamycin, and quinupristin-dalfopristin against 235 strains of Enterococcus faecalis. HMR 3647 was the most active compound (MICs at which 50 and 90% of the isolates are inhibited [MIC50 and MIC90, respectively] of 0.06 and 4.0 μg/ml, respectively). The MIC50 and MIC90 (with the MIC50 given first and the MIC90 given second; both in micrograms per milliliter) for other com...

  11. Fission product yields from 22 MeV neutron-induced fission of 235U

    The chain yields of 28 product nuclides were determined for the fission of 235U induced by 22 MeV neutrons for the first time. Absolute fission rate was monitored with a double-fission chamber. Fission product activities were measured by HPGe γ-ray spectrometry. Time of flight technique was used to measure the neutron spectrum in order to estimate fission events induced by break-up neutrons and scattering neutrons. A mass distribution curve was obtained and the dependence of fission yield on neutron energy is discussed

  12. A `Water Spout' Maser Jet in S235AB-MIR

    Burns, Ross A.; Imai, Hiroshi; HANDA, Toshihiro; Omodaka, Toshihiro; Nakagawa, Akiharu; NAGAYAMA, Takumi; Ueno, Yuji

    2015-01-01

    We report on annual parallax and proper motion observations of H2O masers in S235AB-MIR, which is a massive young stellar object in the Perseus Arm. Using multi-epoch VLBI astrometry we measured a parallax of pi = 0.63 +- 0.03 mas, corresponding to a trigonometric distance of D = 1.56+-0.09 kpc, and source proper motion of ( u alpha cos d , u d) = (0.79 +- 0.12, -2.41 +- 0.14) mas/yr. Water masers trace a jet of diameter 15 au which exhibits a definite radial velocity gradient perpendicular t...

  13. Beyond G-band : a 235 GHz InP MMIC amplifier

    Dawson, Douglas; Samoska, Lorene; Fung, A. K.; Lee, Karen; Lai, Richard; Grundbacher, Ronald; Liu, Po-Hsin; Raja, Rohit

    2005-01-01

    We present results on an InP monolithic millimeter- wave integrated circuit (MMIC) amplifier having 10-dB gain at 235 GHz. We designed this circuit and fabricated the chip in Northrop Grumman Space Technology's (NGST) 0.07- m InP high electron mobility transistor (HEMT) process. Using a WR3 (220-325 GHz) waveguide vector network analyzer system interfaced to waveguide wafer probes, we measured this chip on-wafer for -parameters. To our knowledge, this is the first time a WR3 waveguide on-wafer measurement system has been used to measure gain in a MMIC amplifier above 230 GHz.

  14. Absolute measurement of $sup 235$U fission cross-section for 2200 m/sec neutrons

    Borcea, C.; Borza, A.; Buta, A.

    1973-12-31

    The results of an absolute fission cross-section measurement of /sup 235/ U are presented; the thermal neutrons were selected by the time-of-flight method. The principle of the method and the experimental apparatus are described. The method had the advantage of avoiding the use of an intermediate cross section in the neutron flux determination by choice of a B target thick enough to absorb all thermal neutrons. Target preparation, efficiency determination, corrections, etc., are reported. The value determined was 581.7 plus or minus 7.8 barns. (6 figures, 4 tables) (RWR)

  15. Measurement of reflect neutron for 252Cf in cement cylinder by method of 235U fission

    The experiment theory of Research of neutron reflected coefficient for 252Cf in cement reflector was introduced. The fission rate of 235U with reflector, without reflector and with background was measured. The neutron reflected coefficient with cement reflector was concluded from fission rate and the reflected coefficient for different neutron source in the same experiment model was compared. The relation of reflected coefficient with angle was analyzed. The technology of solid track was researched and the best etch condition was explored. The trend of discharge count with coders thickness and etch thickness was gained. Efficiency for spark auto counters was measured and the technology of solid track was developed. (authors)

  16. New signposts of massive star formation in the S235A-B region

    Felli, M.; Massi, F.; Robberto, M.; Cesaroni, R.

    2006-07-01

    Aims.We report on new aspects of the star-forming region S235AB revealed through high-resolution observations at radio and mid-infrared wavelengths. Methods: .Using the Very Large Array, we carried out sensitive observations of S235AB in the cm continuum (6, 3.6, 1.3, and 0.7) and in the 22 GHz water maser line. These were complemented with Spitzer Space Telescope Infrared Array Camera archive data to clarify the correspondence between radio and IR sources. We made also use of newly presented data from the Medicina water maser patrol, started in 1987, to study the variability of the water masers found in the region. Results: .S235A is a classical HII region whose structure is now well resolved. To the south, no radio continuum emission is detected either from the compact molecular core or from the jet-like structure observed at 3.3 mm, suggesting emission from dust in both cases. We find two new compact radio continuum sources (VLA-1 and VLA-2) and three separate maser spots. VLA-1 coincides with one of the maser spots and with a previously identified IR source (M 1). VLA-2 lies towards S235B and represents the first radio detection from this peculiar nebula that may represent an ionized wind from a more evolved star. The two other maser spots coincide with an elongated structure previously observed within the molecular core in the C34S line. This structure is perpendicular to a bipolar molecular outflow observed in HCO+(1-0) and may trace the associated equatorial disk. The Spitzer images reveal a red object towards the molecular core. This is the most viable candidate for the embedded source originating the outflow and maser phenomenology. Conclusions: .The picture emerging from these and previous data shows the extreme complexity of a small (≤0.5 pc) star-forming region where widely different stages of stellar evolution are present.

  17. Neutron cross sections for uranium-235 (ENDF/B-IV Release 3)

    The resonance parameters in ENDF6 (Release 2) U235 were adjusted to make the average capture and fission cross sections below 900 eV agree with selected differential capture and fission measurements. The measurements chosen were the higher of the credible capture measurements and the lower of the fission results, yielding a higher epithermal alpha. In addition, the 2200 m/s cross sections were adjusted to obtain agreement with the integral value of K1. As a result, criticality calculations for thermal benchmarks, and agreement with a variety of integral parameters, are improved

  18. Test of the ENDF/B [Evaluated Nuclear Data File] unresolved resonance formalism for 235U

    It is common practice in ENDF/B [Evaluated Nuclear Data File] to represent neutron cross sections in the unresolved resonance region by specifying the average values and distribution laws of resonance parameters. This formalism allows the calculation of resonance self-shielding and of its variation with temperature. The purpose of this paper is to present a test of the validity of the formalism by comparing self-shielding factors computed with the ENDF/B unresolved formalism with values computed with the resolved resonance parameters recently evaluated for the neutron cross sections of 235U

  19. Comparison and validation of different 235U fast fission delayed neutron group parameters

    The differences between 235U fast fission delayed neutron group parameters in ENDF/B7, JEFF 3.1, JENDL 3.3, CENDL 2.2 and Keepin datum were analyzed. The delayed neutron group parameters were validated by experiments on CFBR-II. The Keepin delayed neutron group parameters are more accurate than delayed neutron group parameters in the primary nuclear databases. The eight-group delayed neutron parameters in JEEF 3.1 are better than six-group delayed neutron parameters in other databases. (authors)

  20. Are 0.1%-accurate gamma-ray assays possible for 235U solutions

    The factors influencing the accuracy of passive gamma-ray assay of uniform, homogeneous solution samples have been studied in some detail, particularly for the assay of 235U in uranium solutions. Factors considered are the overall long-term electronic stability, the information losses caused by the rate-related electronic processes of pulse pileup and dead-time, and the self-attenuation of gamma rays within the samples. Both experimental and computational studies indicate that gamma-ray assay procedures for solution samples of moderate size (from approx. 10 to perhaps a few hundred milliliters) are now capable of accuracies approaching 0.1% in many practical cases

  1. O polimorfismo AGT*M235T na disfunção cardíaca de etiologia isquêmica aguda: projeto gisca AGT*M235T polymorphism in acute ischemic cardiac dysfunction: the gisca project

    Claudia Guerra Murad Saud

    2010-08-01

    Full Text Available FUNDAMENTO: O polimorfismo AGT*M235T tem sido associado a elevados níveis séricos de angiotensinogênio (AGT, hipertensão arterial sistêmica e disfunção cardíaca (DC. OBJETIVO: Testar a hipótese de haver associação entre polimorfismo AGT*M235T e o risco de desenvolver disfunção cardíaca (insuficiência cardíaca ou disfunção sistólica ventricular esquerda assintomática pós-síndrome coronariana aguda (SCA, durante o período de internação hospitalar. MÉTODOS: Foram estudados 363 pacientes (idade média 62 ± 12 anos, sendo 233 (64% homens e 130 (36% mulheres, todos da mesma coorte, internados por SCA. Compararam-se dados clínicos e genéticos dos 117 (32,2% que evoluíram com disfunção cardíaca (grupo caso com os dos 246 (67,8%, que não desenvolveram tal condição (grupo controle. O polimorfismo AGT*M235T foi determinado por análise de sequenciamento e estava em equilíbrio de Hardy-Weinberg. RESULTADOS: Houve diferença significativa na distribuição dos genótipos nas mulheres, com predomínio do genótipo *235MM no grupo controle (p = 0,001 e do alelo *235T no grupo caso. Em ambos os sexos, nos modelos de regressão logística, o diagnóstico de infarto de parede anterior na admissão foi fator de incremento no risco de DC, enquanto angina instável na admissão, ausência do alelo *235T, glicemia 60 e BACKGROUND: AGT*M235T polymorphism has been associated with high serum angiotensinogen (AGT levels, systemic hypertension and cardiac dysfunction (CD. OBJECTIVE: To test the hypothesis of AGT*M235T polymorphism being associated with the risk of developing cardiac dysfunction (heart failure or asymptomatic left ventricular systolic dysfunction after acute coronary syndrome (ACS during hospitalization. METHODS: A total of 363 patients (mean age of 62 ± 12 years, of whom 233 (64% were men and 130 (36% were women, all from the same cohort and hospitalized for ACS, were studied. Clinical and genetic data from the 117

  2. Critical Experiments to Determine Amount of U-235 in Research Reactor Fuel Assemblies

    Seven different critical core configurations of the IRR1 have been used to determine experimentally the reactivity changes caused by interchanging different fuel assemblies in the same core position(1'2). The data obtained with the first four critical configurations, Cores 1, 2, 3, and 4, are analyzed in this report; the other three will be analyzed and reported in a later paper. The different fuel assemblies (highly enriched MTR type fuel assemblies) interchanged in these cores varied in their burnup or loss in U-235, thus changing the core keff w i t h each interchange. The k∞ of a fuel assembly is a function of its U-235 inventory. The fuel assemblies interchange forced the control blade to alter its height in order to compensate for the change in core reactivity. The control blade reactivity worth as a function of its height was measured by period measurements so the reactivity changes due to the fuel assemblies interchange could be determined. Several different fuel assemblies in each core were measured in this manner. This experimental data can be calculated using reactor physics codes

  3. New Precision Measurements of the U235(n,γ) Cross Section

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Couture, A.; O'Donnell, J. M.; Fowler, M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wouters, J. M.; Wilhelmy, J. B.; Wu, C. Y.; Becker, J. A.

    2012-11-01

    The neutron capture cross section of U235 was measured for the neutron incident energy region between 4 eV and 1 MeV at the DANCE facility at the Los Alamos Neutron Science Center with an unprecedented accuracy of 2-3% at 1 keV. The new methodology combined three independent measurements. In the main experiment, a thick actinide sample was used to determine neutron capture and neutron-induced fission rates simultaneously. In the second measurement, a fission tagging detector was used with a thin actinide sample and detailed characteristics of the prompt-fission gamma rays were obtained. In the third measurement, the neutron scattering background was characterized using a sample of Pb208. The relative capture cross section was obtained from the experiment with the thick U235 sample using a ratio method after the subtraction of the fission and neutron scattering backgrounds. Our result indicates errors that are as large as 30% in the 0.5-2.5 keV region, in the current knowledge of neutron capture as embodied in major nuclear data evaluations. Future modifications of these databases using the improved precision data given herein will have significant impacts in neutronics calculations for a variety of nuclear technologies.

  4. Fission-Neutron Spectra of U235, Pu239 And Cf252

    Measurements of the fission neutron spectra from the neutron-induced fission of U235 and Pu239, and the spontaneous fission of Cf252, have been made. The spectra were measured with a time-of-flight technique using a plastic scintillator as the fission-neutron detector. The low energy part of the Cf252 fission-neutron spectrum (below 0.3 MeV) was also measured with a Li6 -glass detector replacing the plastic scintillator. The fissile materials were mounted in xenon-gas scintillation cham-bers. The primary neutrons were produced by a 2.5-MeV Van de Graaff accelerator with top terminal pulsing. The resolving time of the time-of-flight equipment was better than 3 ns. Results fitted to Maxwellian distributions, √Ee-E/T, are presented for neutron-induced fissions of U235 at 40 keV and 1.5 MeV of incident neutron energy and for Pu239 at 40 keV. Results are also given for the fission-neutron energy spectrum of Cf252. (author)

  5. PC based manual and safety logic card test setup for 235 MWe PHWRs

    Fuel handling controls for 235 MWe PHWR make use of Manual and Logic cards (MLCs) for providing safety interlocks. These cards consist of various type of logic blocks. By connecting these logic blocks all the safety interlocks required for fuel handling controls have been provided. Previously trouble shooting of these cards was done by means of logic probe. Since the method was manual, it was laborious and time consuming. PC based test setup has overcome this drawback and detects the fault at the component level within few seconds. It also gives printout of status of faulty MLC cards. Here motherboard has been designed having slots for insertion of MLC cards. The input/output connection of these cards are coming to two 50 pin FRC connectors. PC communicates through 144 line digital input/output card with MLC card under test. Software is user friendly and outputs suitable input patterns to the card under test and checks for output pattern. It compares this output pattern with compare pattern and detects the fault and displays the symptoms. This system is currently in use at test facility for fuelling machine for 235 MWe PHWR reactor at Refuelling Technology Division, Hall-7. This test setup has been proposed for use at NAPP and future reactors. (author). 4 figs., 1 annexure

  6. Consistent Data Assimilation of Actinide Isotopes: 235U and 239Pu

    In this annual report we illustrate the methodology of the consistent data assimilation that allows to use the information coming from integral experiments for improving the basic nuclear parameters used in cross section evaluation. A series of integral experiments were analyzed using the EMPIRE evaluated files for 235U, 238U, and 239Pu. Inmost cases the results have shown quite large worse results with respect to the corresponding existing evaluations available for ENDF/B-VII. The observed discrepancies between calculated and experimental results were used in conjunction with the computed sensitivity coefficients and covariance matrix for nuclear parameters in a consistent data assimilation. Only the GODIVA and JEZEBEL experimental results were used, in order to exploit information relative to the isotope of interest that are, in this particular case: 235U and 239Pu. The results obtained by the consistent data assimilation indicate that with reasonable modifications (mostly within the initial standard deviation) it is possible to eliminate the original large discrepancies on the Keff of the two critical configurations. However, some residual discrepancy remains for a few fission spectral indices that are, most likely, to be attributed to the detector cross sections.

  7. A multi-wavelength study of star formation activity in the S235 complex

    Dewangan, L K; Luna, A; Anandarao, B G; Ninan, J P; Mallick, K K; Mayya, Y D

    2016-01-01

    We have carried out an extensive multi-wavelength study to investigate the star formation process in the S235 complex. The S235 complex has a sphere-like shell appearance at wavelengths longer than 2 $\\mu$m and harbors an O9.5V type star approximately at its center. Near-infrared extinction map traces eight subregions (having A$_{V}$ $>$ 8 mag), and five of them appear to be distributed in an almost regularly spaced manner along the sphere-like shell surrounding the ionized emission. This picture is also supported by the integrated $^{12}$CO and $^{13}$CO intensity maps and by Bolocam 1.1 mm continuum emission. The position-velocity analysis of CO reveals an almost semi-ring like structure, suggesting an expanding H\\,{\\sc ii} region. We find that the Bolocam clump masses increase as we move away from the location of the ionizing star. This correlation is seen only for those clumps which are distributed near the edges of the shell. Photometric analysis reveals 435 young stellar objects (YSOs), 59\\% of which ar...

  8. Molecular Emission in Dense Massive Clumps from the Star-Forming Regions S231-S235

    Ladeyschikov, D A; Tsivilev, A P; Sobolev, A M

    2016-01-01

    The article deals with observations of star-forming regions S231-S235 in 'quasi-thermal' lines of ammonia (NH$_3$), cyanoacetylene (HC$_3$N) and maser lines of methanol (CH$_3$OH) and water vapor (H$_2$O). S231-S235 regions is situated in the giant molecular cloud G174+2.5. We selected all massive molecular clumps in G174+2.5 using archive CO data. For the each clump we determined mass, size and CO column density. After that we performed observations of these clumps. We report about first detections of NH$_3$ and HC$_3$N lines toward the molecular clumps WB89 673 and WB89 668. This means that high-density gas is present there. Physical parameters of molecular gas in the clumps were estimated using the data on ammonia emission. We found that the gas temperature and the hydrogen number density are in the ranges 16-30 K and 2.8-7.2$\\times10^3$ cm$^{-3}$, respectively. The shock-tracing line of CH$_3$OH molecule at 36.2 GHz is newly detected toward WB89 673.

  9. Measuring the absorption mean cross section in 6Li relative to 235U fission

    Due to the fact that the neutron absorption cross section in 6Li is used as one of standards for determinaton of neutron-physical characteristics of fast reactors the ratio of mean cross sections for absorption by 6Li (A6) and 235U fission F25 are experimentalli investigated. The measurements have been performed in the KBR-8, KBR-10,BFS/39/1 bfs-44, BFS/45a-1 and BFS-46 critical assemblies which are characterized by various neutron spectra by means of a lithium counter with semiconductor detectors. Ratios A6/F25 for investigated assemblies constituted respectively 0.605+-0.009; 0.604+-0.004; 0.581+-0.009; 0.590+-0.574+-0.005. The values of 235U diffusion mean cross sections obtained on the base of these fata and calculated using the CRAB-1 program (given in brackets) are equal respectively 1.53+-0.005 (1.51) 2.38+-0.08 (2.42); 1.935+-0.060 (1.95); 1.89+-0.08 (1.95); 1.780+-0.11 (1.69); 1.90+-0.06 (1.89)

  10. 235 U consumption and 239 Pu formation on IPR-R1 reactor

    On the present world conjuncture it is necessary a rigorous storage and utilization control of nuclear materials under safeguard, specially those considered as strategic and those that could be used on the nuclear armaments fabrications as 235U and 239Pu. Brazil have signed and ratified many international pacts related to the peaceful utilization of the nuclear materials, making the compromise to attend nuclear safeguard procedures accorded with international regulatory organizations. The main goal of this work is the development of a simplified method for the estimation of the 239Pu productivity during the operation of the IPR-R1, TRIGA Mark-1 type, nuclear research reactor, that can achieve the maximum power of 100 KWt. A computational algorithm have been made to calculate the consumption of 235U on the fuel elements used on the reactor and the subsequent 239Pu formation (by the neutronic capture process), using the power generated by the reactor since the first criticality. The particular geometry of this kind of reactor allowed the calculation of the burn factors of the fuel elements discriminated by nuclear concentric rings, based on the thermal neutrons field distribution observed on experiments accomplished during a time period in similar reactors and on the IPR-R1. The simplified block diagram of the process, based on the calculation described above, is presented

  11. Prompt Fission Neutron Experiments on 235U(n,f) and 252Cf(SF)

    Göök, A.; Hambsch, F.-J.; Oberstedt, S.; Vidali, M.

    For nuclear modeling and improved evaluation of nuclear data knowledge about fluctuations of the prompt neutron multiplicity as a function of incident neutron energy is requested for the major actinides 235U and 239Pu. Experimental investigations of the prompt fission neutron emission in resonance neutron induced fission on 235U are taking place at the GELINA facility of the IRMM. The experiment employs an array of neutron scintillation-detectors (SCINTIA) in conjunction with a newly designed 3D position sensitive twin Frisch-grid ionization chamber. A preparatory experiment on prompt fission neutron emission in 252Cf(SF) was undertaken to verify analysis procedures relevant for the implementation of the SCINTIA neutron detector array. The available literature data on the TKE dependence of the multiplicity show strong deviations. Therefore, effort was focused on investigating experimental factors in low efficiency neutron counting experiments that may lead to faulty determination of this dependence. Taking these factors into account a result that agree well with data from high efficiency neutron counting experiments is obtained.

  12. Propagation Channel Comparison between 23.5 and 45 GHz in Conference Scenario

    Jianwu Dou

    2016-01-01

    Full Text Available The characteristics of propagation channel at 23.5 and 45 GHz in an indoor conference room are studied based on hybrid approach. A ray-based simulator which includes the reflection, penetration, diffraction, and diffuse scattering is adopted to generate the massive channel realizations. This platform is well calibrated in path and power delay profile (PDP levels according to some specified measurements at different frequencies. Subsequently, according to the simulated channel samples, the statistical channel model for both the large and small scale characteristics is established based on the alpha-beta approach and extended Saleh-Valenzuela (S-V structure, respectively. Results show that the slope of fitted path loss (PL is less than free space due to the waveguide effect for both 23.5 and 45 GHz in indoor scenario and larger PL is experienced at higher frequency. Additionally, the cluster is more centralized with less spreads and decaying faster in delay domain at 45 GHz.

  13. Calculation of 235U(n,n') cross sections for ENDF/B-VI

    Cross sections for neutron-induced reactions on 235U between 0.01 and 20 MeV have been calculated in a preliminary analysis for the ENDF/B-VI evaluation with particular emphasis on neutron inelastic scattering. A deformed optical model potential that fits total, elastic, inelastic, and low-energy average resonance data is used to calculate direct (n,n') cross sections and transmission coefficients for a Hauser-Feshbach statistical theory analysis using a multiple fission barrier representation. Direct cross sections for higher-lying vibrational states are provided from DWBA calculations, normalized using B(E/ital l/) values determined from (d,d') and Coulomb excitation data. Initial fission barrier parameters and transition state density enhancements appropriate to the compound systems involved were obtained from previous analyses, especially fits to charged-particle fission probability data. Further modifications to fit 235U(n,f) data were small, and the final fission parameters are generally consistent with published values. The results from this preliminary analysis are compared with the ENDF/B-V evaluation as well as with experimental data. 26 refs., 5 figs., 3 tabs

  14. R-matrix analysis of the 235U neutron cross sections

    The ENDFB-V representation of the 235U neutron cross sections in the resolved resonance region is unsatisfactory: below 1 eV the cross sections are given by ''smooth files'' (file 3) rather than by resonance parameters; above 1 eV the single-level formalism used by ENDFB-V necessitates a structured file 3 contribution consisting of more than 1300 energy points; furthermore, information on level-spins has not been included. Indeed the ENDFB-V 235U resonance region is based on an analysis done in 1970 for ENDFB-III and therefore does not include the results of high quality measurements done in the past 18 years. The present paper presents the result of an R-matrix multilevel analysis of recent measurements as well as older data. The analysis also extends the resolved resonance region from its ENDFB-V upper limit of 81 eV to 110 eV. 13 refs., 2 figs., 1 tab

  15. Studies of the Fission Integrals of U-235 and Pu-239 with Cadmium and Filters

    The resonance fissions in U235 and Pu239 have been studied using cadmium and boron filters. Fission chambers were used as detectors and the experiments were performed in beam geometry. The neutron energy distribution in the beams transmitted through the different filters was determined with a fast chopper. From the cadmium filter, measurements the fission resonance integrals were determined. The values obtained were 278±9 b for U235 and 301±10 b for Pu239; 0.5 eV 239 measurements were made in which the fission events were detected from the fission product activity in irradiated foils. Contrary to what has been reported elsewhere the value of the Pu239 resonance integral, found in this way, agreed well with that obtained from the fission chamber measurement. The experiments with the boron filters yielded results which, for the thin filter, agreed well with those calculated from the cross section data given in the Karlsruhe compilation. The discrepancy was larger for the thick filter but the values did not disagree outside the common limits of error

  16. Total kinetic energy release in the fast neutron-induced fission of $^{235}$U

    Yanez, R; King, J; Barrett, J S; Fotiades, N; Lee, H Y

    2015-01-01

    We have measured the total kinetic energy (TKE) release for the $^{235}$U(n,f) reaction for $E_{n}$=2-100 MeV using the 2E method with an array of Si PIN diode detectors. The neutron energies were determined by time of flight measurements using the white spectrum neutron beam at the LANSCE facility. (To calibrate the apparatus, the TKE release for $^{235}$U(n$_{th}$,f) was also measured using a thermal neutron beam from the OSU TRIGA reactor). The TKE decreases non-linearly from 169.0 MeV to 161.4 MeV for $E_{n}$=2-90 MeV. The standard deviation of the TKE distribution is constant from $E_{n}$=20-90 MeV. Comparison of the data with the multi-modal fission model of Brosa indicates the TKE decrease is a consequence of the growth of symmetric fission and the corresponding decrease of asymmetric fission with increasing neutron energy. The average TKE associated with the Brosa superlong, standard I and standard II modes for a given mass is independent of neutron energy.

  17. Prompt Gamma Radiation from Fragments in the Thermal Fission of 235U

    Measurements were made on the gamma radiation emitted from fission fragments in slow neutron induced fission of 235U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way a decay curve was obtained from which the life-time of one of the gamma-emitting states could be estimated. The relative yield of the gamma-rays was determined as a function of mass for different gamma-ray energy portions and two specific time intervals after the fission events. Comparisons were made with data obtained from 252 Cf-fission. Attention is drawn to some features which seem to be the same in 235U and 252 Cf-fission

  18. 238U/235U variations in meteorites: extant 247Cm and implications for Pb-Pb dating.

    Brennecka, G A; Weyer, S; Wadhwa, M; Janney, P E; Zipfel, J; Anbar, A D

    2010-01-22

    The 238U/235U isotope ratio has long been considered invariant in meteoritic materials (equal to 137.88). This assumption is a cornerstone of the high-precision lead-lead dates that define the absolute age of the solar system. Calcium-aluminum-rich inclusions (CAIs) of the Allende meteorite display variable 238U/235U ratios, ranging between 137.409 +/- 0.039 and 137.885 +/- 0.009. This range implies substantial uncertainties in the ages that were previously determined by lead-lead dating of CAIs, which may be overestimated by several million years. The correlation of uranium isotope ratios with proxies for curium/uranium (that is, thorium/uranium and neodymium/uranium) provides strong evidence that the observed variations of 238U/235U in CAIs were produced by the decay of extant curium-247 to uranium-235 in the early solar system, with an initial 247Cm/235U ratio of approximately 1.1 x 10(-4) to 2.4 x 10(-4). PMID:20044543

  19. High accuracy/high precision determination of 235U in nondestructive assay standards by gamma-ray spectroscopy

    High precision gamma spectrometry measurements have been made on five sets of five uranium isotope abundance reference materials for nondestructive assay (NDA). These sets are intended for international safeguards use as primary reference materials for the determination of the 235U abundance in homogeneous uranium bulk material by gamma spectrometry. The measurements are to determine the counting rate uniformity of the 235U 185.7 keV gamma as well as the 235U isotope abundance for each sample. Since the samples are packaged such that the U3O8 is infinitely thick for the 185.7 keV gamma, the measured counting rate is not dependent on the material density. In addition, the activity observed by the detector is colimated to simulate calibration conditions used to measure bulk material in the field. The results of this study indicate that accuracy of 235U determination via gamma spectrometry, in the range of few hundredths of a percent (2sigma), is achievable. The main requirement for achieving this level of accuracy is a set of standards whose 235U isotope abundance are known to within 0.01% (2sigma)

  20. Distribution of nanomole quantities of 235U in young and adult Japanese quail and in the F1 generation. Comparison with 153Gd

    Enriched uranium, 93.16% for 235U, served as a tracer of uranium deposition in an avian species, the Japanese quail. A second label, 153Gd, provided for monitoring of procedures and for estimation of the 235U content of live eggs. Depositions of 235U were greater than for 153Gd in all tissues except the yolk sac and the liver. Skeletal levels for 235U were age- and sex-dependent. Feathers contained only 0.11% of the 235U tracer in contrast to 50% of the endogenous uranium. The results show that 235U provides for tracing uranium metabolism in small animals, since in quail the tracer increased the uranium burden of the body by only 1-8%. (author)

  1. Analysis of 235U enrichment by chemical exchange in U(IV) - U(VI) system on anionite

    Full text: A theoretical study about the 235U enrichment by chemical exchange method in U(IV)-U(VI) system on anion-exchange resins is presented. The 235U isotope concentration profiles along the band were numerically calculated using an accurate mathematical model and simulations were carried out for the situation of product and waste withdrawal and feed supply. By means of numerical simulation, an estimation of the migration time, necessary for a desired enrichment degree, was obtained. The required migration distance, the production of uranium 3 at.% 235U per year and the plant configuration are calculated for different operating conditions. An analysis of the process scale for various experimental conditions is also presented. (authors)

  2. Comparison of {sup 235}U fission cross sections in JENDL-3.3 and ENDF/B-VI

    Kawano, Toshihiko [Kyushu Univ., Fukuoka (Japan); Carlson, Allan D. [National Institute of Standards and Technology (United States); Matsunobu, Hiroyuki [Data Engineering, Inc., Fujisawa, Kanagawa (Japan); Nakagawa, Tsuneo; Shibata, Keiichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Talou, Patrick; Young, Philip G.; Chadwick, Mark B. [Los Alamos National Laboratory, Los Alamos, NM (United States)

    2002-01-01

    Comparisons of evaluated fission cross sections for {sup 235}U in JENDL-3.3 and ENDF/B-VI are carried out. The comparisons are made for both the differential and integral data. The fission cross sections as well as the fission ratios are compared with the experimental data in detail. Spectrum averaged cross sections are calculated and compared with the measurements. The employed spectra are the {sup 235}U prompt fission neutron spectrum, the {sup 252}Cf spontaneous fission neutron spectrum, and the neutron spectrum produced by a {sup 9}Be(d, xn) reaction. For {sup 235}U prompt fission neutron spectrum, the ENDF/B-VI evaluation reproduces experimental averaged cross sections. For {sup 252}Cf and {sup 9}Be(d, xn) neutron spectra, the JENDL-3.3 evaluation gives better results than ENDF/B-VI. (author)

  3. Performance evaluation of indigenous thermal ionization mass spectrometer for determination of 235U/238U atom ratios

    A magnetic sector based Thermal Ionization Mass Spectrometer (TIMS) designed and developed at Technical Physics Division, B.A.R.C., was evaluated for its performance for the determination of 235U/238U atom ratios in uranium samples. This consisted of evaluating the precision and accuracy on the 235U/238U atom ratios in various isotopic reference materials as well as indigenously generated uranium samples. The results obtained by the indigenous TIMS were also compared with those obtained using a commercially available TIMS system. The internal and external precision were found to be around 0.1% for determining 235U/238U atom ratios close to those of natural uranium ( i.e. 0.00730). (author)

  4. EVALUATION OF BORATED ALUMINUM PRODUCTS FOR CRITICALITY CONTROL IN 235-F

    Duncan, A.; Sindelar, R.

    2003-05-06

    Plutonium-containing materials are destined for storage in the 235-F vault. The projected amount of stored materials will require the presence of neutron absorber materials. The leading design concept is for the neutron absorber materials to be in non-load-bearing borated aluminum plates lining the walls of the vault. A comprehensive evaluation of the borated aluminum plate materials was performed to identify a suitable material, and verify that these materials would remain effective as neutron absorbers under normal service conditions and for design-basis events, including the fire accident scenario, throughout a 20-year service life. Aluminum 1100 with boron additions is the recommended neutron absorber material for plutonium material storage in the 235-F vault based on boron loading capacity and durability in the storage environment. Borated aluminum 1100 is commercially available up to 4.5 wt. % boron. A detailed comparison was made of the physical, mechanical, and corrosion properties of borated aluminum alloy 1100 to standard alloy 1100-O (-O designating the fully annealed condition) to demonstrate near-equivalency in properties and to justify application of alloy 1100-O properties to the borated product as needed for the degradation analysis. The expected degradation of the borated aluminum is extremely low for storage conditions, including the bounding scenario of an aggressive atmospheric condition. A maximum loss of 0.00029 inches/year would be expected under potentially aggressive atmospheric conditions and would result in a fractional loss of only 0.42 wt. % of the boron present in a 7mm plate for a 20-year storage period. The fraction of Boron-10 consumption by spontaneous neutrons is expected to be less than 10{sup -8} for the 20-year storage in 235-F fully loaded with Pu materials. The borated aluminum alloy 1100 will be thermally stable and unaltered up to near-melt temperature (643°C). Mechanical testing data at elevated temperatures show that the

  5. Prompt γ-rays from the Fast Neutron Induced Fission on 235,238U and 232Th

    Lebois, M.; Wilson, J. N.; Halipré, P.; Leniau, B.; Matea, I.; Oberstedt, A.; Oberstedt, S.; Verney, D.

    Preliminary results from the first experiment using the LICORNE neutron source at the IPN Orsay are presented. Prompt fission gamma rays from fast-neutron induced fission of 238U, 232Th and 235U were detected. Thick samples of around 50 g of 238U and 232Th are used for the first part of the experiment. An ionisation chamber containing ∼ 10 mg samples of 238U and 235U to provide a fission trigger is used for the second part of the experiment. Gamma rays have been detected using 17 high efficiency BaF2 detectors and 6 LaBr3 scintillator detectors.

  6. Investigation of forming mechanism of instantaneous neutron spectrum of 235U, 239Pu, 252Cf nuclei fission

    Formation mechanism of prompt neutrons spectrum during the fission of the 235U, 239Pu nuclei by thermal and fast neutrons and spontaneous fission of 252Cf is investigated. The formation procedure for prompt neutrons spectrum during the fission of nuclei as superposition of three partial evaporation Weisskopf spectra with the mean energy of neutrons 0.4, 2.06 and 2.8 MeV is proposed. Formation mechanism of the spectrum just as during the fission of the 235U, 239Pu nuclei by thermal and fast neutrons, so spontaneous fission of the 252Cf nuclei is identical

  7. 238U/235U determinations of some commonly used reference materials and U-bearing accessory minerals (Invited)

    Condon, D.; Noble, S.; McLean, N.; Bowring, S. A.

    2009-12-01

    We have determined 238U/235U ratios for a suite of commonly used natural (CRM 112a, SRM 950a, HU-1) and synthetic (IRMM 184 and CRM U500) uranium reference materials in addition to several U-bearing accessory phases (zircon and monazite) by thermal ionisation mass-spectrometry (TIMS) using the IRMM 3636 233U-236U double spike to accurately correct for mass fractionation. The 238U/235U values for the natural uranium reference materials differ, by up to 0.1%, from the widely used ‘consensus’ value (137.88) with all having 238U/235U values less than 137.88. Similarly, initial 238U/235U data from zircon and monazite yield 238U/235U values that are lower than the ‘consensus’ value. The data obtained from U-bearing minerals is used to assess how the uncertainty in the 238U/235U ratio contributes to the systematic discordance observed in 238U/206Pb and 235U/207Pb dates (Mattinson, 2000; Schoene et al., 2006) which has traditionally been wholly attributed to error in the U decay constants. The 238U/235U determinations made on the synthetic reference materials yield results that are considerably more precise and accurate than the certified values (0.02% vs. 0.1% for CRM U500). The calibration of isotopic tracers used for U-daughter geochronology that are partially based upon these reference materials, and the resultant age determinations, will benefit from increased accuracy and precision. Mattinson, J.M., 2000. Revising the “gold standard”—the uranium decay constants of Jaffey et al., 1971. Eos Trans. AGU, Spring Meet. Suppl., Abstract V61A-02. Schoene B., Crowley J.L., Condon D.C., Schmitz M.D., Bowring S.A., 2006, Reassessing the uranium decay constants for geochronology using ID-TIMS U-Pb data. Geochimica et Cosmochimica Acta 70: 426-445

  8. Study of Relationship Between Neutron Energy and Fission Yields of 95Zr, 140Ba and 147Nd From 235U

    2001-01-01

    This work measures fission yields of 235U induced by neutrons with energy of thermal, 3.0, 5.0, 5.5, 8.0 and 14.8 MeV. The main purpose is to study the relationship between neutron energy and fission fields of 95Zr,140Ba and 147Nd from 235U by measuring the radioactivity of foil with direct gamma spectrometry. The fission yields induced by fast neutrons are get by fast-thermal-ratio method which based on yields from thermal neutrons, yields by thermal neutron are come from absolute measurement. Since fast-thermal-ratio method eliminates uncertainties of gamma intensity, gamma

  9. Reich-Moore and Adler-Adler representations of the 235U cross sections in the resolved resonance region

    In the first part of this paper, a reevaluation of the low-energy neutron cross sections of 235U is described. This reevaluation was motivated by the discrepancy between the measured and computed temperature coefficients of reactivity and is based on recent measurements of the fission cross section and of η in the thermal and subthermal neutron energy regions. In the second part of the paper, we discuss the conversion of the Reich-Moore resonance parameters, describing the neutron cross sections of 235U in the resolved resonance region, into equivalent Adler-Adler resonance parameters and into equivalent momentum space multipole resonance parameters

  10. Reich-Moore and Adler-Adler representations of the 235U cross sections in the resolved resonance region

    In the first part of this paper, a reevaluation of the low-energy neutron cross sections of 235U is described. This reevaluation was motivated by the discrepancy between the measured and computed temperature coefficients of reactivity and is based on recent measurements of the fission cross section and of η in the thermal and subthermal neutron energy regions. In the second part of the paper, we discuss the conversion of the Reich-Moore resonance parameters, describing the neutron cross sections of 235U in the resolved resonance region, into equivalent Adler-Adler resonance parameters and into equivalent momentum space multipole resonance parameters. 25 refs., 4 figs., 5 tabs