WorldWideScience

Sample records for californium 238

  1. Californium-252 progress, report No. 7, April 1971

    Energy Technology Data Exchange (ETDEWEB)

    1971-12-31

    This report contains discusses of the following topics on Californium-252: First sales of californium-252; encapsulation services discussed; three new participants in market evaluation program; summer training programs to use californium; Californium-252 shipping casks available; Californium-252 questions and answers, radiotherapy; neutron radiography; natural resources exploration; nuclear safeguards; process control; dosimetry; neutron radiography; neutron shielding; and nuclear safeguards.

  2. Historical review of californium-252 discovery and development

    Science.gov (United States)

    Stoddard, D. H.

    This paper discusses the discovery and history of californium 252. This isotope may be synthesized by irradiating plutonium 239, plutonium 242, americium 243, or curium 244 with neutrons in a nuclear reactor. Various experiments and inventions involving (252)Cf conducted at the Savannah River Plant are discussed. The evolution of radiotherapy using californium 252 is reviewed.

  3. Californium-252: a remarkable versatile radioisotope

    Energy Technology Data Exchange (ETDEWEB)

    Osborne-Lee, I.W.; Alexander, C.W.

    1995-10-10

    A product of the nuclear age, Californium-252 ({sup 252}Cf) has found many applications in medicine, scientific research, industry, and nuclear science education. Californium-252 is unique as a neutron source in that it provides a highly concentrated flux and extremely reliable neutron spectrum from a very small assembly. During the past 40 years, {sup 252}Cf has been applied with great success to cancer therapy, neutron radiography of objects ranging from flowers to entire aircraft, startup sources for nuclear reactors, fission activation for quality analysis of all commercial nuclear fuel, and many other beneficial uses, some of which are now ready for further growth. Californium-252 is produced in the High Flux Isotope Reactor (HFIR) and processed in the Radiochemical Engineering Development Center (REDC), both of which are located at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The REDC/HFIR facility is virtually the sole supplier of {sup 252}Cf in the western world and is the major supplier worldwide. Extensive exploitation of this product was made possible through the {sup 252}Cf Market Evaluation Program, sponsored by the United States Department of Energy (DOE) [then the Atomic Energy Commission (AEC) and later the Energy Research and Development Administration (ERDA)]. This program included training series, demonstration centers, seminars, and a liberal loan policy for fabricated sources. The Market Evaluation Program was instituted, in part, to determine if large-quantity production capability was required at the Savannah River Laboratory (SRL). Because of the nature of the product and the means by which it is produced, {sup 252}Cf can be produced only in government-owned facilities. It is evident at this time that the Oak Ridge research facility can meet present and projected near-term requirements. The production, shipment, and sales history of {sup 252}Cf from ORNL is summarized herein.

  4. Production, Distribution, and Applications of Californium-252 Neutron Sources

    Energy Technology Data Exchange (ETDEWEB)

    Balo, P.A.; Knauer, J.B.; Martin, R.C.

    1999-10-03

    The radioisotope {sup 252}Cf is routinely encapsulated into compact, portable, intense neutron sources with a 2.6-year half-life. A source the size of a person's little finger can emit up to 10{sup 11} neutrons/s. Californium-252 is used commercially as a reliable, cost-effective neutron source for prompt gamma neutron activation analysis (PGNAA) of coal, cement, and minerals, as well as for detection and identification of explosives, laud mines, and unexploded military ordnance. Other uses are neutron radiography, nuclear waste assays, reactor start-up sources, calibration standards, and cancer therapy. The inherent safety of source encapsulations is demonstrated by 30 years of experience and by U.S. Bureau of Mines tests of source survivability during explosions. The production and distribution center for the U. S Department of Energy (DOE) Californium Program is the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL). DOE sells The radioisotope {sup 252}Cf is routinely encapsulated into compact, portable, intense neutron sources with a 2.6- year half-life. A source the size of a person's little finger can emit up to 10 neutrons/s. Californium-252 is used commercially as a reliable, cost-effective neutron source for prompt gamma neutron activation analysis (PGNAA) of coal, cement, and minerals, as well as for detection and identification of explosives, laud mines, and unexploded military ordnance. Other uses are neutron radiography, nuclear waste assays, reactor start-up sources, calibration standards, and cancer therapy. The inherent safety of source encapsulations is demonstrated by 30 years of experience and by U.S. Bureau of Mines tests of source survivability during explosions. The production and distribution center for the U. S Department of Energy (DOE) Californium Program is the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory(ORNL). DOE sells {sup 252}Cf to commercial

  5. Unusual structure, bonding and properties in a californium borate

    Energy Technology Data Exchange (ETDEWEB)

    Polinski, Matthew J.; Garner, Edward B.; Maurice, Rémi; Planas, Nora; Stritzinger, Jared T.; Parker, T. Gannon; Cross, Justin N.; Green, Thomas D.; Alekseev, Evgeny V.; Van Cleve, Shelley M.; Depmeier, Wulf; Gagliardi, Laura; Shatruk, Michael; Knappenberger, Kenneth L.; Liu, Guokui; Skanthakumar, S.; Soderholm, Lynda; Dixon, David A.; Albrecht-Schmitt, Thomas E.

    2014-03-23

    The participation of the valence orbitals of actinides in bonding has been debated for decades. Recent experimental and computational investigations demonstrated the involvement of 6p, 6d and/or 5f orbitals in bonding. However, structural and spectroscopic data, as well as theory, indicate a decrease in covalency across the actinide series, and the evidence points to highly ionic, lanthanide-like bonding for late actinides. Here we show that chemical differentiation between californium and lanthanides can be achieved by using ligands that are both highly polarizable and substantially rearrange on complexation. A ligand that suits both of these desired properties is polyborate. We demonstrate that the 5f, 6d and 7p orbitals are all involved in bonding in a Cf(III) borate, and that large crystal-field effects are present. Synthetic, structural and spectroscopic data are complemented by quantum mechanical calculations to support these observations.

  6. Biomedical neutron research at the Californium User Facility for neutron science

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.C. [Oak Ridge National Lab., TN (United States); Byrne, T.E. [Roane State Community College, Harriman, TN (United States); Miller, L.F. [Univ. of Tennessee, Knoxville, TN (United States)

    1997-04-01

    The Californium User Facility for Neutron Science has been established at Oak Ridge National Laboratory (ORNL). The Californium User Facility (CUF) is a part of the larger Californium Facility, which fabricates and stores compact {sup 252}Cf neutron sources for worldwide distribution. The CUF can provide a cost-effective option for research with {sup 252}Cf sources. Three projects at the CUF that demonstrate the versatility of {sup 252}Cf for biological and biomedical neutron-based research are described: future establishment of a {sup 252}Cf-based neutron activation analysis system, ongoing work to produce miniature high-intensity, remotely afterloaded {sup 252}Cf sources for tumor therapy, and a recent experiment that irradiated living human lung cancer cells impregnated with experimental boron compounds to test their effectiveness for boron neutron capture therapy.

  7. Apparatus for the measurement of total body nitrogen using prompt neutron activation analysis with californium-252.

    Science.gov (United States)

    Mackie, A; Hannan, W J; Smith, M A; Tothill, P

    1988-01-01

    Details of clinical apparatus designed for the measurement of total body nitrogen (as an indicator of body protein), suitable for the critically ill, intensive-care patient are presented. Californium-252 radio-isotopic neutron sources are used, enabling a nitrogen measurement by prompt neutron activation analysis to be made in 40 min with a precision of +/- 3.2% for a whole body dose equivalent of 0.145 mSv. The advantages of Californium-252 over alternative neutron sources are discussed. A comparison between two irradiation/detection geometries is made, leading to an explanation of the geometry adopted for the apparatus. The choice of construction and shielding materials to reduce the count rate at the detectors and consequently to reduce the pile-up contribution to the nitrogen background is discussed. Salient features of the gamma ray spectroscopy system to reduce spectral distortion from pulse pile-up are presented.

  8. Safety Analysis Report for Packaging (SARP) of the Oak Ridge National Laboratory TRU Californium Shipping Container

    Energy Technology Data Exchange (ETDEWEB)

    Box, W.D.; Shappert, L.B.; Seagren, R.D.; Klima, B.B.; Jurgensen, M.C.; Hammond, C.R.; Watson, C.D.

    1980-01-01

    An analytical evaluation of the Oak Ridge National Laboratory TRU Californium Shipping Container was made in order to demonstrate its compliance with the regulations governing off-site shipment of packages that contain radioactive material. The evaluation encompassed five primary categories: structural integrity, thermal resistance, radiation shielding, nuclear criticality safety, and quality assurance. The results of this evaluation demonstrate that the container complies with the applicable regulations.

  9. Economical Production of Pu-238

    Energy Technology Data Exchange (ETDEWEB)

    Steven D. Howe; Douglas Crawford; Jorge Navarro; Terry Ring

    2013-02-01

    All space exploration missions traveling beyond Jupiter must use radioisotopic power sources for electrical power. The best isotope to power these sources is plutonium-238. The US supply of Pu-238 is almost exhausted and will be gone within the next decade. The Department of Energy has initiated a production program with a $10M allocation from NASA but the cost is estimated at over $100 M to get to production levels. The Center for Space Nuclear Research has conceived of a potentially better process to produce Pu-238 earlier and for significantly less cost. The new process will also produce dramatically less waste. Potentially, the front end costs could be provided by private industry such that the government only had to pay for the product produced. Under a NASA Phase I NIAC grant, the CSNR has evaluated the feasibility of using a low power, commercially available nuclear reactor to produce at least 1.5 kg of Pu-238 per year. The impact on the neutronics of the reactor have been assessed, the amount of Neptunium target material estimated, and the production rates calculated. In addition, the size of the post-irradiation processing facility has been established. In addition, a new method for fabricating the Pu-238 product into the form used for power sources has been identified to reduce the cost of the final product. In short, the concept appears to be viable, can produce the amount of Pu-238 needed to support the NASA missions, can be available within a few years, and will cost significantly less than the current DOE program.

  10. 49 CFR 238.115 - Emergency lighting.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Emergency lighting. 238.115 Section 238.115... § 238.115 Emergency lighting. (a) This section applies to each passenger car ordered on or after... applies to each level of a multi-level passenger car. (b) Emergency lighting shall be provided in each...

  11. 46 CFR 153.238 - Required materials.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Required materials. 153.238 Section 153.238 Shipping... BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Containment Systems § 153.238 Required materials. When one of the following paragraphs of this section is...

  12. 16 CFR 238.1 - Bait advertisement.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Bait advertisement. 238.1 Section 238.1 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES AGAINST BAIT ADVERTISING § 238.1 Bait advertisement. No advertisement containing an offer to sell a product should be published...

  13. 49 CFR 238.231 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake system. 238.231 Section 238.231... Equipment § 238.231 Brake system. Except as otherwise provided in this section, on or after September 9... train's primary brake system shall be capable of stopping the train with a service application from its...

  14. 49 CFR 238.427 - Suspension system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Suspension system. 238.427 Section 238.427... Equipment § 238.427 Suspension system. (a) General requirements. (1) Suspension systems shall be designed to... equipment. (2) Passenger equipment shall meet the safety performance standards for suspension systems...

  15. 49 CFR 238.425 - Electrical system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Electrical system. 238.425 Section 238.425... Equipment § 238.425 Electrical system. (a) Circuit protection. (1) The main propulsion power line shall be.... (b) Main battery system. (1) The main batteries shall be isolated from the cab and passenger seating...

  16. 49 CFR 238.225 - Electrical system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Electrical system. 238.225 Section 238.225... Equipment § 238.225 Electrical system. All passenger equipment shall comply with the following: (a... derated for grouping and for operating temperature. (b) Main battery system. (1) The main battery...

  17. 49 CFR 238.431 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake system. 238.431 Section 238.431... Equipment § 238.431 Brake system. (a) A passenger train's brake system shall be capable of stopping the... train is operating under worst-case adhesion conditions. (b) The brake system shall be designed to allow...

  18. 49 CFR 238.227 - Suspension system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Suspension system. 238.227 Section 238.227 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Equipment § 238.227 Suspension system. On or after November 8, 1999— (a) All passenger equipment shall...

  19. 49 CFR 238.217 - Side structure.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Side structure. 238.217 Section 238.217 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Equipment § 238.217 Side structure. Each passenger car shall comply with the following: (a) Side posts and...

  20. Two /sup 238/Pu inhalation incidents

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, R.R.; Hall, R.M.

    1978-06-01

    Two employees inhaled significant amounts of /sup 238/Pu in separate unrelated contamination incidents in 1977. Both acute exposure incidents are described and the urine, feces, and in-vivo chest count data for each employee. Case B (/sup 238/PuNO/sub 3/) received 24 DTPA treatments beginning the day of the incident while, for medical reasons, Case A (/sup 238/PuO/sub 2/) received no therapy.

  1. 8 CFR 238.1 - Proceedings under section 238(b) of the Act.

    Science.gov (United States)

    2010-01-01

    ... contents of the Notice of Intent to the alien in the alien's native language or in a language that the... EXPEDITED REMOVAL OF AGGRAVATED FELONS § 238.1 Proceedings under section 238(b) of the Act. (a) Definitions...

  2. 33 CFR 238.8 - Other participation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Other participation. 238.8 Section 238.8 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF... Other participation. In addition to providing flood damage reduction works in urban areas, the Corps may...

  3. 49 CFR 238.423 - Fuel tanks.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Fuel tanks. 238.423 Section 238.423 Transportation....423 Fuel tanks. (a) External fuel tanks. Each type of external fuel tank must be approved by FRA's Associate Administrator for Safety upon a showing that the fuel tank provides a level of safety at least...

  4. 49 CFR 238.439 - Doors.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Doors. 238.439 Section 238.439 Transportation....439 Doors. (a) Each passenger car shall have a minimum of two exterior side doors, each door providing... required by § 239.107(a) of this chapter. [64 FR 25660, May 12, 1999, as amended at 67 FR 19993, Apr. 23...

  5. Dicty_cDB: CHF238 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available CH (Link to library) CHF238 (Link to dictyBase) - - - Contig-U11696-1 CHF238P (Link to Original site) CHF...238F 138 CHF238Z 218 CHF238P 336 - - Show CHF238 Library CH (Link to library) Clone ID CHF... URL http://dictycdb.biol.tsukuba.ac.jp/CSM/CH/CHF2-B/CHF238Q.Seq.d/ Representative seq. ID CHF...238P (Link to Original site) Representative DNA sequence >CHF238 (CHF238Q) /CSM/CH/CHF2-B/CHF2...Sequences producing significant alignments: (bits) Value CHF238 (CHF238Q) /CSM/CH/CHF2-B/CHF238Q.Seq.d/ 359

  6. Dicty_cDB: VHB238 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHB238 (Link to dictyBase) - - - Contig-U15541-1 VHB238P (Link to Original site) VHB...238F 614 VHB238Z 813 VHB238P 1407 - - Show VHB238 Library VH (Link to library) Clone ID VHB...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHB2-B/VHB238Q.Seq.d/ Representative seq. ID VHB...238P (Link to Original site) Representative DNA sequence >VHB238 (VHB238Q) /CSM/VH/VHB2-B/VHB...is Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VHB238 (VHB

  7. Application of TSH bioindicator for studying the biological efficiency of neutrons from californium-252 source

    Energy Technology Data Exchange (ETDEWEB)

    Cebulska-Wasilewska, A.; Rekas, K. [Institute of Nuclear Physics, Cracow (Poland); Kim, J.K. [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)

    1997-12-31

    The effectiveness of neutrons from a Californium-252 source in the induction of various abnormalities in the Tradescantia clone 4430 stamen hair cells (TSH-assay) was studied. The special attention was paid to check whether any enhancement in effects caused by process of boron neutron capture is visible in the cells enriched with boron ions. Two chemicals (borax and BSH) were applied to introduce boron-10 ions into cells. Inflorescence, normal or pretreated with chemicals containing boron, were irradiated in the air with neutrons from a Cf-252 source at KAERI, Taejon, Korea. To estimate the relative biological effectiveness (RBE) in the induction of gene mutations of the neutron beam under the study, Tradescantia inflorescences, without any chemical pretreatment, were irradiated with various doses of X-rays. The ranges of radiation doses used were 0-0.1 Gy in neutrons and 0-0.5 Gy in X-rays. After the time needed to complete the postirradiation repair Tradescantia cuttings were transferred to Cracow, where screening of gene and lethal; mutations, cell cycle alterations in somatic cells have been done, and dose response relationships were figured. The maximal RBE values were estimated in the range of 4.6-6.8. Alterations of RBE value were observed; from 6.8 to 7.8 in the case of plants pretreated with 240 ppm of B-10 from borax, and 4.6 to 6.1 in the case of 400 ppm of B-10 from BSH. Results showed a slight, although statistically insignificant increase in biological efficacy of radiation from the Cf-252 source in samples pretreated with boron containing chemicals. (author)

  8. Study of the shielding for spontaneous fission sources of Californium-252; Estudio de blindaje para fuentes de fision espontanea de Californio-252

    Energy Technology Data Exchange (ETDEWEB)

    Davila R, I

    1991-06-15

    A shielding study is made to attenuate, until maximum permissible levels, the neutrons radiation and photons emitted by spontaneous fission coming from a source of Californium-252. The compound package by a database (Library DLC-23) and the ANISNW code is used, in it version for personal computer. (Author)

  9. 33 CFR 238.5 - Comprehensive planning.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Comprehensive planning. 238.5... Comprehensive planning. Coordinated comprehensive planning at the regional or river basin level, or for an urban.... This planning is particularly important in areas where significant portions of a watershed are expected...

  10. /sup 238/U issues resolved and unresolved

    Energy Technology Data Exchange (ETDEWEB)

    de Saussure, G.; Smith, A.B.

    1982-01-01

    The interaction of 1 eV to 20 MeV neutrons with /sup 238/U is discussed with emphasis on recently resolved and remaining issues relevant to both application need and physical understanding. The apparent inability of older /sup 238/U evaluations to predict the measured /sup 238/U capture rate in thermal critical lattices has stimulated several recent precise measurements of the /sup 238/U cross sections, reanalysis of older data, and improved evaluations. The recent evaluations predict satisfactorily the /sup 238/U capture rate in thermal critical lattices. In the region from 1.5 to 4 keV there are differences of the order of 15%, sometimes larger, between the values of the neutron widths of the main resonances reported by several experimenters or obtained by different evaluators. Above 4 keV there are only sparse results of resonance analysis and most evaluations adopt a statistical treatment of the resonance structure. Some factors affecting the determination of the average properties of the resonance parameters are discussed. Above the inelastic-scattering threshold, energy-averaged neutron total, scattering, capture and fission cross sections are reviewed in a unified manner integrating measurement, calculation and evaluation. (n;n') and (n;2n') energy-transfer mechanisms are addressed. Particular attention is given to neutron capture, stressing precisions consistent with applied need. Fission properties are discussed including: prompt and delayed fission-neutron spectra and nubar, and fission-product yields. Physical understanding is assayed, with attention to compound-nucleus and direct-reaction mechanisms, and applications impact is illustrated in the context of fast-breeder-reactor performance. 95 references.

  11. 43 CFR 23.8 - Approval of mining plan.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Approval of mining plan. 23.8 Section 23.8 Public Lands: Interior Office of the Secretary of the Interior SURFACE EXPLORATION, MINING AND RECLAMATION OF LANDS § 23.8 Approval of mining plan. (a) Before surface mining operations may commence under...

  12. 49 CFR 238.603 - Safety planning requirements.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Safety planning requirements. 238.603 Section 238... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Specific Safety Planning Requirements for Tier II Passenger Equipment § 238.603 Safety planning requirements. (a) Prior to commencing...

  13. 33 CFR 110.238 - Apra Harbor, Guam.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Apra Harbor, Guam. 110.238 Section 110.238 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.238 Apra Harbor, Guam. (a) The anchorage grounds (Datum: WGS...

  14. 40 CFR 238.10 - Purpose and applicability.

    Science.gov (United States)

    2010-07-01

    ... Section 238.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING DEGRADABLE PLASTIC RING CARRIERS General Provisions § 238.10 Purpose and applicability. The purpose of this part is to require that plastic ring carriers be made of degradable materials as described in §§ 238.20...

  15. 49 CFR 238.114 - Rescue access windows.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Rescue access windows. 238.114 Section 238.114... § 238.114 Rescue access windows. (a) Number and location. Except as provided in paragraph (a)(1)(ii) of... rescue access windows. At least one rescue access window shall be located in each side of the car...

  16. 49 CFR 238.407 - Anti-climbing mechanism.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Anti-climbing mechanism. 238.407 Section 238.407... Equipment § 238.407 Anti-climbing mechanism. (a) Each power car shall have an anti-climbing mechanism at its... before the anti-climbing mechanism fully engages. (b) Interior train coupling points between units...

  17. 49 CFR 238.205 - Anti-climbing mechanism.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Anti-climbing mechanism. 238.205 Section 238.205... Equipment § 238.205 Anti-climbing mechanism. (a) Except as provided in paragraph (b) of this section, all..., 2010, shall have at both the forward and rear ends an anti-climbing mechanism capable of resisting an...

  18. 49 CFR 238.319 - Running brake test.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received, or...

  19. Simulation and design of an electron beam ion source charge breeder for the californium rare isotope breeder upgrade

    Directory of Open Access Journals (Sweden)

    Clayton Dickerson

    2013-02-01

    Full Text Available An electron beam ion source (EBIS will be constructed and used to charge breed ions from the californium rare isotope breeder upgrade (CARIBU for postacceleration into the Argonne tandem linear accelerator system (ATLAS. Simulations of the EBIS charge breeder performance and the related ion transport systems are reported. Propagation of the electron beam through the EBIS was verified, and the anticipated incident power density within the electron collector was identified. The full normalized acceptance of the charge breeder with a 2 A electron beam, 0.024π  mm mrad for nominal operating parameters, was determined by simulating ion injection into the EBIS. The optics of the ion transport lines were carefully optimized to achieve well-matched ion injection, to minimize emittance growth of the injected and extracted ion beams, and to enable adequate testing of the charge bred ions prior to installation in ATLAS.

  20. Extraction of Trivalent Actinides and Lanthanides from Californium Campaign Rework Solution Using TODGA-based Solvent Extraction System

    Energy Technology Data Exchange (ETDEWEB)

    Benker, Dennis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Delmau, Laetitia Helene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dryman, Joshua Cory [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-07-01

    This report presents the studies carried out to demonstrate the possibility of quantitatively extracting trivalent actinides and lanthanides from highly acidic solutions using a neutral ligand-based solvent extraction system. These studies stemmed from the perceived advantage of such systems over cationexchange- based solvent extraction systems that require an extensive feed adjustment to make a low-acid feed. The targeted feed solutions are highly acidic aqueous phases obtained after the dissolution of curium targets during a californium (Cf) campaign. Results obtained with actual Cf campaign solutions, but highly diluted to be manageable in a glove box, are presented, followed by results of tests run in the hot cells with Cf campaign rework solutions. It was demonstrated that a solvent extraction system based on the tetraoctyl diglycolamide molecule is capable of quantitatively extracting trivalent actinides from highly acidic solutions. This system was validated using actual feeds from a Cf campaign.

  1. Beyond Californium-A Neutron Generator Alternative for Dosimetry and Instrument Calibration in the U.S.

    Science.gov (United States)

    Piper, Roman K; Mozhayev, Andrey V; Murphy, Mark K; Thompson, Alan K

    2017-09-01

    Evaluations of neutron survey instruments, area monitors, and personal dosimeters rely on reference neutron radiations, which have evolved from the heavy reliance on (α,n) sources to a shared reliance on (α,n) and the spontaneous fission neutrons of californium-252 (Cf). Capable of producing high dose equivalent rates from an almost point source geometry, the characteristics of Cf are generally more favorable when compared to the use of (α,n) and (γ,n) sources or reactor-produced reference neutron radiations. Californium-252 is typically used in two standardized configurations: unmoderated, to yield a fission energy spectrum; or with the capsule placed within a heavy-water moderating sphere to produce a softened spectrum that is generally considered more appropriate for evaluating devices used in nuclear power plant work environments. The U.S. Department of Energy Cf Loan/Lease Program, a longtime origin of affordable Cf sources for research, testing and calibration, was terminated in 2009. Since then, high-activity sources have become increasingly cost-prohibitive for laboratories that formerly benefited from that program. Neutron generators, based on the D-T and D-D fusion reactions, have become economically competitive with Cf and are recognized internationally as important calibration and test standards. Researchers from the National Institute of Standards and Technology and the Pacific Northwest National Laboratory are jointly considering the practicality and technical challenges of implementing neutron generators as calibration standards in the U.S. This article reviews the characteristics of isotope-based neutron sources, possible isotope alternatives to Cf, and the rationale behind the increasing favor of electronically generated neutron options. The evaluation of a D-T system at PNNL has revealed characteristics that must be considered in adapting generators to the task of calibration and testing where accurate determination of a dosimetric quantity is

  2. Californium-252 Brachytherapy Combined With External-Beam Radiotherapy for Cervical Cancer: Long-Term Treatment Results

    Energy Technology Data Exchange (ETDEWEB)

    Lei Xin; Qian Chengyuan; Qing Yi; Zhao Kewei; Yang Zhengzhou; Dai Nan; Zhong Zhaoyang; Tang Cheng; Li Zheng; Gu Xianqing; Zhou Qian; Feng Yan; Xiong Yanli; Shan Jinlu [Cancer Center, Research Institute of Surgery and Daping Hospital, Third Military Medical University, Chongqing (China); Wang Dong, E-mail: dongwang64@hotmail.com [Cancer Center, Research Institute of Surgery and Daping Hospital, Third Military Medical University, Chongqing (China)

    2011-12-01

    Purpose: To observe, by retrospective analysis, the curative effects and complications due to californium-252 ({sup 252}Cf) neutron intracavitary brachytherapy (ICBT) combined with external-beam radiotherapy (EBRT) in the treatment of cervical cancer. Methods and Materials: From February 1999 to December 2007, 696 patients with cervical cancer (Stages IB to IIIB) were treated with {sup 252}Cf-ICBT in combination of EBRT. Of all, 31 patients were at Stage IB, 104 at IIA, 363 at IIB, 64 at IIIA, and 134 at IIIB. Californium-252 ICBT was delivered at 7-12 Gy per insertion per week, with a total dose of 29-45 Gy to reference point A in three to five insertions. The whole pelvic cavity was treated with 8-MV X-ray external irradiation at 2 Gy per fraction, four times per week. After 16-38 Gy of external irradiation, the center of the whole pelvic field was blocked with a 4-cm-wide lead shield, with a total external irradiation dose of 44-56 Gy. The total treatment course was 5 to 6 weeks. Results: Overall survival rate at 3 and 5 years for all patients was 76.0% and 64.9%, respectively. Disease-free 3- and 5-year survival rates of patients were 71.2% and 58.4%, respectively. Late complications included vaginal contracture and adhesion, radiation proctitis, radiation cystitis, and inflammatory bowel, which accounted for 5.8%, 7.1%, 6.2%, and 4.9%, respectively. Univariate analysis results showed significant correlation of stage, age, histopathologic grade, and lymph node status with overall survival. Cox multiple regression analysis showed that the independent variables were stage, histopathologic grade, tumor size, and lymphatic metastasis in all patients. Conclusion: Results of this series suggest that the combined use of {sup 252}Cf-ICBT with EBRT is an effective method for treatment of cervical cancer.

  3. HANFORD Pu-238 DRUM INTEGRITY ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    CANNELL, G.R.

    2004-10-20

    Hanford is presently retrieving contact-handled, transuranic (CH-TRU) waste drums from the site's Low-Level Burial Grounds (LLBG) for processing and disposition. A subgroup of these drums (12 total), referred to as Pu-238 drums, has some unique characteristics that may impact the current drum handling and processing activities. These characteristics include content, shielding, thermal, pressurization and criticality issues. An effort to evaluate these characteristics, for the purpose of developing a specific plan for safe retrieval of the Pu-238 drums, is underway. In addition to the above evaluation, the following integrity assessment of the inner container material and/or confinement properties, with primary emphasis on the Source Capsule (primary confinement barrier) and Shipping Container has been performed. Assessment included review of the inner container materials and the potential impact the service history may have had on material and/or confinement properties. Several environmental degradation mechanisms were considered with the objective of answering the following question: Is it likely the container material and/or confinement properties have been significantly altered as a result of service history?

  4. Heavy actinide production in the reactions of /sup 238/U+/sup 238/U and /sup 238/U+/sup 248/Cm

    CERN Document Server

    Gaggeler, H; Ferguson, R L; Hahn, R L; Herrmann, G; Hulet, E K; Kratz, J V; Lougheed, R W; Nitschke, J M; Peuser, P; Schädel, M; Stakemann, R; Sümmerer, K; Tittel, G; Trautmann, N; Wirth, G

    1981-01-01

    Experiments on the production of heavy actinides up to mendelevium from the reactions between /sup 238/U on /sup 238/U and /sup 238/U on /sup 248/Cm are summarized. The authors find that independent of the system and the bombarding energy an average of about 4 neutrons is emitted from the primary fragments implying average excitation energies of 30 to 40 MeV in the heavy fragments. An intercomparison of their data with results obtained with lighter particles like /sup 48 /Ca, /sup 84/Kr and /sup 136/Xe on /sup 238/U and /sup 248/Cm targets, respectively, shows increased formation cross sections for heavy actinides with /sup 238/U as projectile. In addition, for the /sup 238 /U+/sup 238/U reaction cross sections for americium shape isomers are determined. Deduced isomer-to-ground-state ratios are found to be lower as compared to light particle induced reactions. With a simple model estimates of production rates for very heavy elements up to z =104 have been performed for the reactions of /sup 238/U on /sup 248...

  5. Neutron data evaluation of {sup 238}U

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, V.M.; Porodzinskij, Y.V.; Hasegawa, Akira; Shibata, Keiichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-08-01

    Cross sections for neutron-induced reactions on {sup 238}U are calculated by using the Hauser-Feshbach-Moldauer theory, the coupled channel model and the double-humped fission barrier model. The direct excitation of ground state band levels is calculated with a rigid-rotator model. The direct excitation of vibrational octupole and K = 2{sup +} quadrupole bands is included using a soft (deformable) rotator model. The competition of inelastic scattering to fission reaction is shown to be sensitive to the target nucleus level density at excitations above the pairing gap. As for fission, (n,2n), (n,3n), and (n,4n) reactions, secondary neutron spectra data are consistently reproduced. Pre-equilibrium emission of first neutron is included. Shell effects in the level densities are shown to be important for estimation of energy dependence of non-emissive fission cross section. (author). 105 refs.

  6. Initial Eccentricity in Deformed 197Au+197Au and 238U+238U Collisions at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Filip, Peter; Lednicky, Richard; Masui, Hiroshi; Xu, Nu

    2010-07-07

    Initial eccentricity and eccentricity fluctuations of the interaction volume created in relativistic collisions of deformed {sup 197}Au and {sup 238}U nuclei are studied using optical and Monte-Carlo (MC) Glauber simulations. It is found that the non-sphericity noticeably influences the average eccentricity in central collisions and eccentricity fluctuations are enhanced due to deformation. Quantitative results are obtained for Au+Au and U+U collisions at energy {radical}s{sub NN} = 200 GeV.

  7. Long-term effects of an intracavitary treatment with californium-252 on normal tissue. [Swine, /sup 226/Ra

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, M.F.; Beamer, J.L.; Mahony, T.D.; Cross, F.T.; Lund, J.E.; Endres, G.W.R.

    1976-01-01

    About one hundred fifty swine were exposed to either radium-226 or californium-252 sources in the uterine cervix to determine an RBE for both acute and long-term effects. That value for early changes in the tissues at risk in the treatment of cervical cancer was between 6.2 and 6.8. The incidence of complications increased with time after exposure, especially among animals treated with /sup 252/Cf. Analysis of rectal injury showed that ulceration occurred frequently within a year postexposure at doses between 1600 and 2400 rad calculated at 2 cm lateral to the source midline. Fat necrosis and smooth muscle atrophy, resulting in a local rectal stricture, were delayed changes observed in some animals. The lower ureter was the site for a greater frequency of complications than the GI tract. Ureteral stricture often occurred at doses of 1200 rad from /sup 252/Cf and 7000 rad from /sup 226/Ra. Observation of delayed effects in the uterine-cervix in animals held up to 4 years postexposure indicate that the RBE for /sup 252/Cf may be increased to a value as high as 18, while repair may have even decreased it to about 5.6 in the rectum. Fifty swine are still being observed for long-term effects after doses above 800 rad from /sup 252/Cf and 5000 rad from /sup 226/Ra.

  8. 49 CFR 238.107 - Inspection, testing, and maintenance plan.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Inspection, testing, and maintenance plan. 238.107... Requirements § 238.107 Inspection, testing, and maintenance plan. (a) General. Beginning on January 1, 2002... develop, and provide to FRA upon request, a detailed inspection, testing, and maintenance plan consistent...

  9. 49 CFR Appendix - Part 238, Subpart C, Figure 1

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Part 238, Subpart C, Figure 1 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Specific Requirements for Tier I Passenger Equipment Automated monitoring. Pt. 238, Subpt, C, Fig....

  10. 49 CFR 238.233 - Interior fittings and surfaces.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Interior fittings and surfaces. 238.233 Section... I Passenger Equipment § 238.233 Interior fittings and surfaces. (a) Each seat in a passenger car... determined by the railroad: (1) Longitudinal: 8g; (2) Vertical: 4g; and (3) Lateral: 4g. (c) Other interior...

  11. 49 CFR 238.435 - Interior fittings and surfaces.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Interior fittings and surfaces. 238.435 Section... II Passenger Equipment § 238.435 Interior fittings and surfaces. (a) Each seat back and seat.... (d)(1) Other interior fittings shall be attached to the passenger car body with sufficient strength...

  12. /sup 238/U capture rate measurements in FFTF

    Energy Technology Data Exchange (ETDEWEB)

    Rawlins, J.A.; Wootan, D.W.; Dobbin, K.D.; Daughtry, J.W.; Matsumoto, W.Y.

    1983-01-01

    Calculation overpredicts the in-core /sup 238/U(n,..gamma..) reaction rate in FFTF driver fuel by approximately 8%. Dosimetry-based adjustment calculations indicate the calculated neutron spectrum in fuel requires significant adjustment below 3 keV, and the /sup 238/U capture cross section above 500 eV needs downward adjustment to achieve consistency.

  13. 49 CFR 238.405 - Longitudinal static compressive strength.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Longitudinal static compressive strength. 238.405... II Passenger Equipment § 238.405 Longitudinal static compressive strength. (a) To form an effective... shall resist a minimum longitudinal static compressive force of 2,100,000 pounds without permanent...

  14. 49 CFR 238.203 - Static end strength.

    Science.gov (United States)

    2010-10-01

    ... describe the likely performance of the static end strength of the equipment and the likely performance of the equipment in derailment and collision scenarios pertinent to the equipment's static end strength... 49 Transportation 4 2010-10-01 2010-10-01 false Static end strength. 238.203 Section 238.203...

  15. 49 CFR 238.315 - Class IA brake test.

    Science.gov (United States)

    2010-10-01

    ... and release of the brakes on the last car in the train; and (6) The communicating signal system is... be used to verify the set and release on cars so equipped. However, the observation of the brake... 49 Transportation 4 2010-10-01 2010-10-01 false Class IA brake test. 238.315 Section 238.315...

  16. 40 CFR 86.238-94-86.239-94 - [Reserved

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false 86.238-94-86.239-94 Section 86.238-94-86.239-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... 1994 and Later Model Year Gasoline-Fueled New Light-Duty Vehicles, New Light-Duty Trucks and New Medium...

  17. 16 CFR 238.0 - Bait advertising defined. 1

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Bait advertising defined. 1 238.0 Section... BAIT ADVERTISING § 238.0 Bait advertising defined. 1 1 For the purpose of this part “advertising” includes any form of public notice however disseminated or utilized. Bait advertising is an alluring but...

  18. Electron scattering from the octupole band in /sup 238/U

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, A.; Creswell, C.; Bertozzi, W.; Heisenberg, J.; Hynes, M.V.; Kowalski, S.; Miska, H.; Norum, B.; Rad, F.N.; Sargent, C.P.; Sasanuma, T.; Turchinetz, W.

    1978-03-06

    A simple model for nuclear surface vibrations in permanently deformed nuclei does well in reproducing electron scattering cross sections of rotational levels built on a K/sup ..pi../= 0/sup -/ intrinsic octupole vibration in /sup 238/U.

  19. Ab initio full-potential study of mechanical properties and magnetic phase stability of californium monopnictides (CfN and CfP)

    Energy Technology Data Exchange (ETDEWEB)

    Amari, S., E-mail: siham_amari@yahoo.fr [Faculté des Sciences de la Nature et de la Vie, Université Hassiba Benbouali, Chlef, 02000 (Algeria); Bouhafs, B. [Laboratoire de Modélisation et Simulation en Sciences des Matériaux, Université Djillali Liabès de Sidi Bel-Abbés, Sidi Bel-Abbés, 22000 (Algeria)

    2016-09-15

    Based on the first-principles methods, the structural, elastic, electronic, properties and magnetic ordering of californium monopnictides CfX (X = P) have been studied using the full-potential augmented plane wave plus local orbitals (FP-L/APW + lo) method within the framework of density functional theory (DFT). The electronic exchange correlation energy is described by generalized gradient approximation GGA and GGA+U (U is the Hubbard correction). The GGA+U method is applied to the rare-earth 5f states. We have calculated the lattice parameters, bulk modulii and the first pressure derivatives of the bulk modulii. The elastic properties of the studied compounds are only investigated in the most stable calculated phase. In order to gain further information, we have calculated Young’s modulus, shear modulus, anisotropy factor and Kleinman parameter by the aid of the calculated elastic constants. The results mainly show that californium monopnictides CfX (X = P) have an antiferromagnetic spin ordering. Density of states (DOS) and charge densities for both compounds are also computed in the NaCl (B1) structure.

  20. Economical Production of Pu-238: NIAC Phase I Final Report

    Science.gov (United States)

    Howe, Steven D.; Crawford, Douglas; Navarro, Jorge; O'Brien, Robert C.; Katalenich, Jeff; Ring, Terry

    2016-01-01

    All space exploration missions traveling beyond Jupiter must use radioisotopic power sources for electrical power. The best isotope to power these sources is plutonium-238 (Pu-238). The US supply of Pu-238 is almost exhausted and will be gone within the next decade. The Department of Energy has initiated a production program with a $10M allocation from NASA but the cost is estimated at over $100M to get to production levels. The Center for Space Nuclear Research (CSNR) has conceived of a potentially better process to produce Pu-238 earlier and for significantly less cost. Potentially, the front end capital costs could be provided by private industry such that the government only had to pay for the product produced. In the Phase I NIAC (NASA Innovative Advanced Concepts) grant, the CSNR has evaluated the feasibility of using a low power, commercially available nuclear reactor to produce 1.5 kg of Pu-238 per year. The impact on the neutronics of the reactor have been assessed, the amount of Neptunium target material estimated, and the production rates calculated. In addition, the size of the post-irradiation processing facility has been established. Finally, as the study progressed, a new method for fabricating the Pu-238 product into the form used for power sources has been identified to reduce the cost of the final product. In short, the concept appears to be viable, can produce the amount of Pu-238 needed to support the NASA missions, can be available within a few years, and will cost significantly less than the current DOE program.

  1. Low-Dose-Rate Californium-252 Neutron Intracavitary Afterloading Radiotherapy Combined With Conformal Radiotherapy for Treatment of Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Min [Department of Oncology, Armed Police Hospital of Hangzhou, Hangzhou, Zhejiang Province (China); Xu Hongde [Cancer Center, Armed Police Hospital of Hangzhou, Hangzhou, Zhejiang Province (China); Pan Songdan; Lin Shan; Yue Jianhua [Department of Oncology, Armed Police Hospital of Hangzhou, Hangzhou, Zhejiang Province (China); Liu Jianren, E-mail: liujianren0571@hotmail.com [Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province (China)

    2012-07-01

    Purpose: To study the efficacy of low-dose-rate californium-252 ({sup 252}Cf) neutron intracavitary afterloading radiotherapy (RT) combined with external pelvic RT for treatment of cervical cancer. Methods and Materials: The records of 96 patients treated for cervical cancer from 2006 to 2010 were retrospectively reviewed. For patients with tumors {<=}4 cm in diameter, external beam radiation was performed (1.8 Gy/day, five times/week) until the dose reached 20 Gy, and then {sup 252}Cf neutron intracavitary afterloading RT (once/week) was begun, and the frequency of external beam radiation was changed to four times/week. For patients with tumors >4 cm, {sup 252}Cf RT was performed one to two times before whole-pelvis external beam radiation. The tumor-eliminating dose was determined by using the depth limit of 5 mm below the mucosa as the reference point. In all patients, the total dose of the external beam radiation ranged from 46.8 to 50 Gy. For {sup 252}Cf RT, the dose delivered to point A was 6 Gy/fraction, once per week, for a total of seven times, and the total dose was 42 Gy. Results: The mean {+-} SD patient age was 54.7 {+-} 13.7 years. Six patients had disease assessed at stage IB, 13 patients had stage IIA, 49 patients had stage IIB, 3 patients had stage IIIA, 24 patients had stage IIIB, and 1 patient had stage IVA. All patients obtained complete tumor regression (CR). The mean {+-} SD time to CR was 23.5 {+-} 3.4 days. Vaginal bleeding was fully controlled in 80 patients within 1 to 8 days. The mean {+-} SD follow-up period was 27.6 {+-} 12.7 months (range, 6-48 months). Five patients died due to recurrence or metastasis. The 3-year survival and disease-free recurrence rates were 89.6% and 87.5 %, respectively. Nine patients experienced mild radiation proctitis, and 4 patients developed radiocystitis. Conclusions: Low-dose-rate {sup 252}Cf neutron RT combined with external pelvic RT is effective for treating cervical cancer, with a low incidence of

  2. Neutron Capture Cross Section Measurement on $^{238}$Pu at DANCE

    Energy Technology Data Exchange (ETDEWEB)

    Chyzh, A; Wu, C Y

    2011-02-14

    The proposed neutron capture measurement for {sup 238}Pu was carried out in Nov-Dec, 2010, using the DANCE array at LANSCE, LANL. The total beam-on-target time is about 14 days plus additional 5 days for the background measurement. The target was prepared at LLNL with the new electrplating cell capable of plating the {sup 238}Pu isotope simultaneously on both sides of the 3-{micro}m thick Ti backing foil. A total mass of 395 {micro}g with an activity of 6.8 mCi was deposited onto the area of 7 mm in diameter. The {sup 238}Pu sample was enriched to 99.35%. The target was covered by 1.4 {micro}m double-side aluminized mylar and then inserted into a specially designed vacuum-tight container, shown in Fig. 1, for the {sup 238}Pu containment. The container was tested for leaks in the vacuum chamber at LLNL. An identical container without {sup 238}Pu was made as well and used as a blank for the background measurement.

  3. Characterization of Pu-238 Heat Source Granule Containment

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Paul Dean II [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sanchez, Joey Leo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wall, Angelique Dinorah [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chavarria, Rene [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-11

    The Milliwatt Radioisotopic Themoelectric Generator (RTG) provides power for permissive-action links. Essentially these are nuclear batteries that convert thermal energy to electrical energy using a doped silicon-germanium thermopile. The thermal energy is provided by a heat source made of 238Pu, in the form of 238PuO2 granules. The granules are contained by 3 layers of encapsulation. A thin T-111 liner surrounds the 238PuO2 granules and protects the second layer (strength member) from exposure to the fuel granules. An outer layer of Hastalloy-C protects the T-111 from oxygen embrittlement. The T-111 strength member is considered the critical component in this 238PuO2 containment system. Any compromise in the strength member seen during destructive testing required by the RTG surveillance program is characterized. The T-111 strength member is characterized through Scanning Electron Microscopy (SEM), and Metallography. SEM is used in the Secondary Electron mode to reveal possible grain boundary deformation and/or cracking in the region of the strength member weld. Deformation and cracking uncovered by SEM are further characterized by Metallography. Metallography sections are mounted and polished, observed using optical microscopy, then documented in the form of microphotographs. SEM mat further be used to examine polished Metallography mounts to characterize elements using the SEM mode of Energy Dispersive X-ray spectroscopy (EDS).

  4. The influence of recycling on mantle 238U/235U?

    Science.gov (United States)

    Andersen, M. B.; Elliott, T.

    2011-12-01

    The highly sub-chondritic Th/U (~2.5) of typical mid-ocean ridge basalts (MORB) is puzzling a much higher integrated Th/U (~3.8) evident from 208Pb/206Pb measurements [1,2]. A popular explanation of this problem has been to invoke recycling of U from the surface into the mantle since the Great Oxidation Event [e.g. 3]. It is intriguing that the lowering of Th/U seems concentrated in the upper mantle, such that MORB have lower Th/U than ocean island basalts (OIB), which are thought to be derived from deeper seated upwellings. This observation potentially informs on the style and vigour of mantle convection. Although an attractive hypothesis, it is uncertain if the recycled U fluxes over the last 2Ga are sufficient to lower the Th/U of MORB to 2.5 [4], despite recent improvements in estimates of modern recycling rates [5]. High precision stable U isotopic measurements [6,7] offer a new means to test this model and we present new data that pertains to the problem. Variations in 238U/235U are related to low-temperature processes on Earth, with some of the largest variations observed in oceanic material (e.g. black shales). Thus recycled material may have 238U/235U that deviates significantly from bulk Earth. We initially wish to contrast the isotopic composition of seawater U, which is quantitatively transferred to the oceanic crust by high temperature hydrothermal alteration, with high Th/U mantle derived samples. Such measurements allow us to discern if we will be able to resolve 238U/235U differences between high Th/U OIB and low Th/U MORB as a result of recycling. We have measured the 238U/235U compositions of a suite of well-characterised OIB and related samples with high precision (±20 ppm, 2 SD). The measured OIBs include samples from La Palma and Azores, spanning a wide range of Th/U compositions. The measured OIBs have identical 238U/235U compositions within ± 20 ppm (2 SD) and these are 100 ppm heavier than modern seawater. This indicates that MORB should

  5. Pu-238 assay performance with the Canberra IQ3 system

    Energy Technology Data Exchange (ETDEWEB)

    Booth, L.; Gillespie, B.; Seaman, G.

    1997-11-01

    Canberra Industries has recently completed a demonstration project at the Westinghouse Savannah River Site (WSRC) to characterize 55-gallon drums containing Pu-238 contaminated waste. The goal of this project was to detect and quantify Pu-238 contaminated waste. The goal of this project was to detect and quantify Pu-238 waste to detection limits of less than 50 nCi/g using gamma assay techniques. This would permit reclassification of these drums from transuranic (TRU) waste to low-level waste (LLW). The instrument used for this assay was a Canberra IQ3 high sensitivity gamma assay system, mounted in a trailer. The results of the measurements demonstrate achievement of detection levels as low as 1 nCi/g for low density waste drums, and good correlation with known concentrations in several test drums. In addition, the data demonstrates significant advantages for using large area low-energy germanium detectors for achieving the lowest possible MDAs for gamma rays in the 80-250 keV range. 1 fig., 2 tabs.

  6. Mechanical properties of /sup 238/PuO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, J.J.; Hecker, S.S.; Land, C.C.; Rohr, D.L.

    1977-04-01

    The mechanical properties of /sup 238/PuO/sub 2/ have been examined in the Los Alamos Scientific Laboratory mechanical test facility built to handle ..cap alpha..-radioactive materials. Compression tests were conducted as a function of temperature, strain rate, grain size, density, and storage time. At temperatures less than or equal to 1400/sup 0/C, test specimens of /sup 238/PuO/sub 2/ exhibit pseudobrittle behavior due to internal cracks. Plastic deformation is ''localized'' at the crack tips. Generalized plastic deformation is observed at 1500/sup 0/C. Ultimate stress values decrease markedly with increasing temperature and decreasing strain rate, and decrease less with decreasing density, increasing storage time, and increasing grain size. Room temperature fracture is transgranular, whereas intergranular fracture predominates at elevated temperatures. Crack-free specimens of /sup 239/PuO/sub 2/ exhibit extensive plastic deformation at 1000/sup 0/C and above. The relationship of these test results to the impact properties of /sup 238/PuO/sub 2/ fuel in radioisotope thermoelectric generators is discussed.

  7. Radiolysis and corrosion of 238 Pu-doped UO2 pellets in chloride ...

    Indian Academy of Sciences (India)

    radiation from 238Pu. Experiments are conducted with 238Pu doped pellets and others with 238Pu dissolved in the brine. The radiolysis products and yields of mobilized U and Pu from the oxidative dissolution of UO2 are determined. Results ...

  8. 49 CFR 238.207 - Link between coupling mechanism and car body.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Link between coupling mechanism and car body. 238.207 Section 238.207 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... Requirements for Tier I Passenger Equipment § 238.207 Link between coupling mechanism and car body. All...

  9. 40 CFR 745.238 - Fees for accreditation and certification of lead-based paint activities.

    Science.gov (United States)

    2010-07-01

    ... certification of lead-based paint activities. 745.238 Section 745.238 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.238 Fees for accreditation and certification of lead...

  10. 78 FR 1848 - Plutonium-238 Production for Radioisotope Power Systems for National Aeronautics and Space...

    Science.gov (United States)

    2013-01-09

    ... Plutonium-238 Production for Radioisotope Power Systems for National Aeronautics and Space Administration...-238 (Pu-238) for radioisotope power systems (RPSs) to support the National Aeronautics and Space... Radioisotope Power Systems (Draft Consolidation EIS) in 2005 to consolidate the nuclear operations related to...

  11. 10 CFR 72.238 - Issuance of an NRC Certificate of Compliance.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Issuance of an NRC Certificate of Compliance. 72.238 Section 72.238 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT... WASTE Approval of Spent Fuel Storage Casks § 72.238 Issuance of an NRC Certificate of Compliance. A...

  12. 75 FR 76953 - Foreign-Trade Zone 238-Dublin, VA Site Renumbering Notice

    Science.gov (United States)

    2010-12-10

    ... Foreign-Trade Zones Board Foreign-Trade Zone 238--Dublin, VA Site Renumbering Notice Foreign-Trade Zone 238 was approved by the Foreign-Trade Zones Board on August 5, 1999 (Board Order 1047). FTZ 238... information, contact Maureen Hinman at [email protected]trade.gov or (202) 482-0627. Dated: December 1, 2010...

  13. 49 CFR 238.219 - Truck-to-car-body attachment.

    Science.gov (United States)

    2010-10-01

    ... section, the mass of the truck includes axles, wheels, bearings, the truck-mounted brake system... 49 Transportation 4 2010-10-01 2010-10-01 false Truck-to-car-body attachment. 238.219 Section 238... I Passenger Equipment § 238.219 Truck-to-car-body attachment. Passenger equipment shall have a truck...

  14. 37 CFR 2.38 - Use by predecessor or by related companies.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Use by predecessor or by related companies. 2.38 Section 2.38 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES The Written Application § 2.38...

  15. /sup 238/Pu fuel form processes. Final report, January-September 1983

    Energy Technology Data Exchange (ETDEWEB)

    Mosley, W.C.; Taylor, D.H.

    1983-01-01

    Progress is reported on the following: analytical studies of weld-quench cracking in DOP-26 iridium alloy, iridium//sup 238/PuO/sub 2/ compatibility test, surface area measurements of /sup 238/PuO/sub 2/ using the Blaine air permeability apparatus, and helium release from /sup 238/PuO/sub 2/. (MHR)

  16. Reexamining the heavy-ion reactions 238U+238U and 238U+248Cm and actinide production close to the barrier

    Science.gov (United States)

    Kratz, J. V.; Schädel, M.; Gäggeler, H. W.

    2013-11-01

    Recent theoretical work has renewed interest in radiochemically determined isotope distributions in reactions of 238U projectiles with heavy targets that had previously been published only in parts. These data are being reexamined. The cross sections σ(Z) below the uranium target have been determined as a function of incident energy in thick-target bombardments. These are compared to predictions by a diffusion model whereby consistency with the experimental data is found in the energy intervals 7.65-8.30 MeV/u and 6.06-7.50 MeV/u. In the energy interval 6.06-6.49 MeV/u, the experimental data are lower by a factor of 5 compared to the diffusion model prediction indicating a threshold behavior for massive charge and mass transfer close to the barrier. For the intermediate energy interval, the missing mass between the primary fragment masses deduced from the generalized Qgg systematics including neutron pair-breaking corrections and the centroid of the experimental isotope distributions as a function of Z have been used to determine the average excitation energy as a function of Z. From this, the Z dependence of the average total kinetic-energy loss (TKEL¯) has been determined. This is compared to that measured in a thin-target counter experiment at 7.42 MeV/u. For small charge transfers, the values of TKEL¯ of this work are typically about 30 MeV lower than in the thin-target experiment. This difference is decreasing with increasing charge transfer developing into even slightly larger values in the thick-target experiment for the largest charge transfers. This is the expected behavior which is also found in a comparison of the partial cross sections for quasielastic and deep-inelastic reactions in both experiments. The cross sections for surviving heavy actinides, e.g., 98Cf, 99Es, and 100Fm indicate that these are produced in the low-energy tails of the dissipated energy distributions, however, with a low-energy cutoff at about 35 MeV. Excitation functions show

  17. Phosphate fertilizer influence on {sup 238} U content in vegetables

    Energy Technology Data Exchange (ETDEWEB)

    Lauria D, C.; Rodrigues S, J.I. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN), Av. Salvador Allende s/n, Rio de Janeiro-RJ (Brazil); Ribeiro, F.C.A. [Centro Regional de Ciencias Nucleares (CRCN/CNEN) Av. Prof. Luiz Freire 200 Cidade Universitaria Recife-PE (Brazil)]. e-mail: dejanira@ird.gov.br

    2006-07-01

    Uranium is a naturally radioactive element, which is usually found in soils, superficial and ground water, vegetables and animals. After ingestion by human beings, most is excreted in few days by feces and urine, without reaching the bloodstream. However, a small part circulates through the body, being accumulated in the soft tissues, as kidneys. A minor fraction can remain in bones per some years, being able through the radioactive decay to irradiate adjacent tissues. Phosphate fertilizers used in conventional crop management can present variable amounts of uranium. In accordance with origin and use, the fertilizer can raise the content of this element in vegetables, and consequently to increase the human exposure for radiation due the consumption of vegetables. It is estimated that the use of phosphate fertilizer has at least doubled the prolonged exposure of humans from ingestion of food. This work aims to evaluate the contribution of organic and chemical fertilizer on the concentration of {sup 238} U in vegetable samples. An experiment with black beans (a very important vegetable for Brazilian people) was conducted in a field which soil has never been fertilized with any sort of fertilizer, located near to the Rio de Janeiro city. On the organic management, bovine manure was used, while on conventional management urea, potassium chloride and superphosphate were used. Simultaneously, black bean samples from not fertilized management were collected. In addition, lettuce and carrot samples from organic and conventional managements were collected in Nova Friburgo farms (the most important vegetable supplier of Rio de Janeiro city market). The analyses of {sup 238} U have been carried out by conventional fluorimetric method. The geometric mean of {sup 238} U concentrations in the carrot and lettuce samples from conventional management were similar with those from organic management, while for beans the conventional samples had higher values than those ones found in

  18. Neutron Induced Capture and Fission Processes on 238U

    Directory of Open Access Journals (Sweden)

    Oprea Cristiana

    2016-01-01

    Full Text Available Nuclear data on Uranium isotopes are of crucial interest for new generation of nuclear reactors. Processes of interest are the nuclear reactions induced by neutrons and in this work mainly the capture and the fission process on 238U will be analyzed in a wide energy interval. For slow and resonant neutrons the many levels Breit – Wigner formalism is necessary. In the case of fast and very fast neutrons up to 200 MeV the nuclear reaction mechanism implemented in Talys will be used. The present evaluations are necessary in order to obtain the field of neutrons in the design of nuclear reactors and they are compared with experimental data from literature obtained from capture and (n,xn processes.

  19. Summary of Plutonium-238 Production Alternatives Analysis Final Report

    Energy Technology Data Exchange (ETDEWEB)

    James Werner; Wade E. Bickford; David B. Lord; Chadwick D. Barklay

    2013-03-01

    The Team implemented a two-phase evaluation process. During the first phase, a wide variety of past and new candidate facilities and processing methods were assessed against the criteria established by DOE for this assessment. Any system or system element selected for consideration as an alternative within the project to reestablish domestic production of Pu-238 must meet the following minimum criteria: Any required source material must be readily available in the United States, without requiring the development of reprocessing technologies or investments in systems to separate material from identified sources. It must be cost, schedule, and risk competitive with existing baseline technology. Any identified facilities required to support the concept must be available to the program for the entire project life cycle (notionally 35 years, unless the concept is so novel as to require a shorter duration). It must present a solution that can generate at least 1.5 Kg of Pu-238 oxide per year, for at least 35 years. It must present a low-risk, near-term solution to the National Aeronautics and Space Administration’s urgent mission need. DOE has implemented this requirement by eliminating from project consideration any alternative with key technologies at less than Technology Readiness Level 5. The Team evaluated the options meeting these criteria using a more detailed assessment of the reasonable facility variations and compared them to the preferred option, which consists of target irradiation at the Advanced Test Reactor (ATR) and the High Flux Isotope Reactor (HFIR), target fabrication and chemical separations processing at the ORNL Radiochemical Engineering Development Center, and neptunium 237 storage at the Materials and Fuels Complex at INL. This preferred option is consistent with the Records of Decision from the earlier National Environmental Policy Act (NEPA) documentation

  20. TNF-α -238, -308, -863 polymorphisms, and brucellosis infection.

    Science.gov (United States)

    Eskandari-Nasab, Ebrahim; Moghadampour, Mehdi; Sepanj-Nia, Adel

    2016-01-01

    Brucella abortus is an intracellular bacterium that affects humans and domestic animals. Tumor necrosis factor-alpha (TNF-α) has been shown as a key player in the induction of cell-mediated resistance against Brucella infection. We aimed to evaluate the possible influence of the TNF-α promoter polymorphisms (-308 G/A, -238 G/A, and -863 C/A) on the susceptibility of human brucellosis. A total of 153 patients with active brucellosis and 128 healthy individuals were recruited. All subjects were genotyped for the polymorphisms in the TNF-α gene by Allele-Specific polymerase chain reaction analysis. Our results showed that the TNF-α -308 GG genotype was significantly more frequently present in controls than in brucellosis patients (91% vs. 75%), thus was a protective factor against developing brucellosis (OR=0.313, p=0.001). In contrast, the -308 GA genotype (OR=3.026, p=0.002) and minor allele (A) (OR=3.058, p=0.001) as well as AAG haplotype (OR=4.014, p=0.001) conferred an increased risk of brucellosis. However, the -238 G/A and -863 C/A polymorphisms were not associated with the risk of brucellosis at both allelic and genotypic levels (p>0.05). Our study revealed that the TNF-α -308 A allele or GA heterozygosity or AAG haplotype were associated with an increased risk of brucellosis in our population. Copyright © 2015 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  1. Californium-252 neutron intracavity brachytherapy alone for T1N0 low-lying rectal adenocarcinoma: A definitive anal sphincter-preserving radiotherapy

    Science.gov (United States)

    Xiong, Yanli; Shan, Jinlu; Liu, Jia; Zhao, Kewei; Chen, Shu; Xu, Wenjing; Zhou, Qian; Yang, Mei; Lei, Xin

    2017-01-01

    This study evaluated the 4-year results of 32 patients with T1N0 low-lying rectal adenocarcinoma treated solely with californium-252 (Cf-252) neutron intracavity brachytherapy (ICBT). Patients were solicited into the study from January 2008 to June 2011. All the patients had refused surgery or surgery was contraindicated. The patients were treated with Cf-252 neutron ICBT using a novel 3.5-cm diameter off-axis 4-channel intrarectal applicator designed by the authors. The dose reference point was defined on the mucosa surface, with a total dose of 55–62 Gy-eq/4 f (13–16 Gy-eq/f/wk). All the patients completed the radiotherapy in accordance with our protocol. The rectal lesions regressed completely, and the acute rectal toxicity was mild (≤G2). The 4-year local control, overall survival, disease-free survival, and late complication (≥G2) rates were 96.9%, 90.6%, 87.5% and 15.6%, respectively. No severe late complication (≥G3) occurred. The mean follow-up was 56.1 ± 16.0 months. At the end of last follow-up, 29 patients remained alive. The mean survival time was 82.1 ± 2.7 months. Cf-252 neutron ICBT administered as the sole treatment (without surgery) for patients with T1N0 low-lying rectal adenocarcinoma is effective with acceptable late complications. Our study and method offers a definitive anal sphincter-preserving radiotherapy for T1N0 low-lying rectal adenocarcinoma patients. PMID:28094790

  2. National low-level waste management program radionuclide report series, Volume 15: Uranium-238

    Energy Technology Data Exchange (ETDEWEB)

    Adams, J.P.

    1995-09-01

    This report, Volume 15 of the National Low-Level Waste Management Program Radionuclide Report Series, discusses the radiological and chemical characteristics of uranium-238 ({sup 238}U). The purpose of the National Low-Level Waste Management Program Radionuclide Report Series is to provide information to state representatives and developers of low-level radioactive waste disposal facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the waste disposal facility environment. This report also includes discussions about waste types and forms in which {sup 238}U can be found, and {sup 238}U behavior in the environment and in the human body.

  3. Dose effect for South Serbians due to {sup 238}U in natural drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, S.K.; Matsumoto, M.; Shiraishi, K.; Fujimoto, K. [Department of Radiation Dosimetry, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Cuknic, O.; Zunic, Z.S. [Institute of Nuclear Sciences, VINCA, PO Box 522, 11001 Belgrade (Serbia)

    2007-07-01

    The use of depleted uranium ammunition in South Serbia during the 1999 Kosovo conflict raised a great deal of public concern in the Balkans. Radioactivity levels of {sup 238}U in 20 wells and lake water samples were checked from the viewpoint of internal radiation exposure for South Serbian subjects. We have measured {sup 238}U concentration using inductively coupled plasma mass spectrometry, whereas thermal ionisation mass spectrometry has been used for the measurement of isotope ratios, e.g. {sup 234}U/{sup 238}U and {sup 235}U/{sup 238}U. The concentration of uranium in water samples varies in the range 1.37-63.18 mBq/L. {sup 234}U belongs to the {sup 238}U natural radioactive decay series, and at secular equilibrium, the abundance ratio, {sup 234}U/{sup 238}U, corresponds to the ratio of their half-lives. The {sup 234}U/{sup 238}U activity ratio varies in the range 0.88-2.2 and {sup 235}U/{sup 238}U isotope ratio varies from 0.00698 to 0.00745. These findings indicate that uranium in water was a mixture of natural and anthropogenic origin. The annual effective dose due to {sup 238}U was estimated to be in the range 9.2 x 10{sup -5} - 2.1 x 10{sup -3} mSv. (authors)

  4. Capability to Recover Plutonium-238 in H-Canyon/HB-Line - 13248

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Kenneth S. Jr.; Smith, Robert H. Jr.; Goergen, Charles R. [Savannah River Nuclear Solutions, LLC, Savannah River Site, Aiken, SC 29802 (United States)

    2013-07-01

    Plutonium-238 is used in Radioisotope Thermoelectric Generators (RTGs) to generate electrical power and in Radioisotope Heater Units (RHUs) to produce heat for electronics and environmental control for deep space missions. The domestic supply of Pu-238 consists of scrap material from previous mission production or material purchased from Russia. Currently, the United States has no significant production scale operational capability to produce and separate new Pu-238 from irradiated neptunium-237 targets. The Department of Energy - Nuclear Energy is currently evaluating and developing plans to reconstitute the United States capability to produce Pu-238 from irradiated Np-237 targets. The Savannah River Site had previously produced and/or processed all the Pu-238 utilized in Radioisotope Thermoelectric Generators (RTGs) for deep space missions up to and including the majority of the plutonium for the Cassini Mission. The previous full production cycle capabilities included: Np- 237 target fabrication, target irradiation, target dissolution and Np-237 and Pu-238 separation and purification, conversion of Np-237 and Pu-238 to oxide, scrap recovery, and Pu-238 encapsulation. The capability and equipment still exist and could be revitalized or put back into service to recover and purify Pu-238/Np-237 or broken General Purpose Heat Source (GPHS) pellets utilizing existing process equipment in HB-Line Scrap Recovery, and H-Canyon Frame Waste Recovery processes. The conversion of Np-237 and Pu-238 to oxide can be performed in the existing HB-Line Phase-2 and Phase- 3 Processes. Dissolution of irradiated Np-237 target material, and separation and purification of Np-237 and Pu-238 product streams would be possible at production rates of ∼2 kg/month of Pu-238 if the existing H-Canyon Frames Process spare equipment were re-installed. Previously, the primary H-Canyon Frames equipment was removed to be replaced: however, the replacement project was stopped. The spare equipment

  5. 48 CFR 552.238-70 - Identification of Electronic Office Equipment Providing Accessibility for the Handicapped.

    Science.gov (United States)

    2010-10-01

    ... Electronic Office Equipment Providing Accessibility for the Handicapped. 552.238-70 Section 552.238-70... Equipment Providing Accessibility for the Handicapped. As prescribed in 538.273(a)(1), insert the following clause: Identification of Electronic Office Equipment Providing Accessibility for the Handicapped (SEP...

  6. 77 FR 9177 - Federal Housing Administration (FHA): Suspension of Section 238(c) Single-Family Mortgage...

    Science.gov (United States)

    2012-02-16

    ..., rehabilitation, or purchase of property located near any installation of the Armed Forces of the United States in... Section 238(c) Single-Family Mortgage Insurance in Military Impacted Areas AGENCY: Office of the Assistant... under section 238(c) of the National Housing Act. This single-family mortgage insurance program...

  7. 50 CFR 23.8 - What are the information collection requirements?

    Science.gov (United States)

    2010-10-01

    ... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) CONVENTION ON INTERNATIONAL TRADE IN ENDANGERED SPECIES OF WILD... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false What are the information collection requirements? 23.8 Section 23.8 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF...

  8. 49 CFR 238.447 - Train operator's controls and power car cab layout.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Train operator's controls and power car cab layout. 238.447 Section 238.447 Transportation Other Regulations Relating to Transportation (Continued... layout. (a) Train operator controls in the power car cab shall be arranged so as to minimize the chance...

  9. 49 CFR 238.111 - Pre-revenue service acceptance testing plan.

    Science.gov (United States)

    2010-10-01

    ... the times and places of the pre-revenue service tests to permit FRA observation of such tests. For... 49 Transportation 4 2010-10-01 2010-10-01 false Pre-revenue service acceptance testing plan. 238... and General Requirements § 238.111 Pre-revenue service acceptance testing plan. (a) Passenger...

  10. 49 CFR 238.105 - Train electronic hardware and software safety.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Train electronic hardware and software safety. 238... and General Requirements § 238.105 Train electronic hardware and software safety. The requirements of this section apply to electronic hardware and software used to control or monitor safety functions in...

  11. [A satisfaction survey of the evolution of 238 otoplasty].

    Science.gov (United States)

    Aguilar, R; Soto, C; Barrena, S; Díaz, M; López, J C; Ros, Z; Tovar, J

    2008-04-01

    The prominent ear is a frequent problem that can be a source of important psychosocial troubles. The aim of this paper has been to evaluate the psychosocial repercussion, cosmetic result and degree of satisfaction in patients treated at our Institution for prominent ears in the last 4 years. A questionnaire has been sent to 127 patients. All of them underwent Mustarde's otoplasty. 238 otoplasty were performed in 127 patients (87% bilateral procedures). The mean age was 8.15 +/- 3.25 years (range: 1-15 years), with a follow-up of 27.15 +/- 13.62 months (range: 4-52 months). Sixty-two % of the patients underwent otoplasty without having self-image affected while 38% of the group were patients older enough to see surgery to correct a long-standing defect. Patients did not require a period of postoperative psychosocial adjustment to their new appearance. Two patients described their results of surgery as little improvement. Three undergo partial recurrence and 5 suffered from total recurrence. All of the patients resume their lives with an improved level of self confidence. Conclusions. Otoplasty is a safe procedure for prominent ears to be considered in children with psycosocial, emotional or behavioural effects.

  12. Elastic and inelastic scattering of neutrons on 238U nucleus

    Directory of Open Access Journals (Sweden)

    Capote R.

    2014-04-01

    Full Text Available Advanced modelling of neutron induced reactions on the 238U nucleus is aimed at improving our knowledge of neutron scattering. Capture and fission channels are well constrained by available experimental data and neutron standard evaluation. A focus of this contribution is on elastic and inelastic scattering cross sections. The employed nuclear reaction model includes – a new rotational-vibrational dispersive optical model potential coupling the low-lying collective bands of vibrational character observed in even-even actinides; – the Engelbrecht-Weidenmüller transformation allowing for inclusion of compound-direct interference effects; – and a multi-humped fission barrier with absorption in the secondary well described within the optical model for fission. Impact of the advanced modelling on elastic and inelastic scattering cross sections including angular distributions and emission spectra is assessed both by comparison with selected microscopic experimental data and integral criticality benchmarks including measured reaction rates (e.g. JEMIMA, FLAPTOP and BIG TEN. Benchmark calculations provided feedback to improve the reaction modelling. Improvement of existing libraries will be discussed.

  13. Natural Isotopic Fractionation of 238U/235U in the Water Column of the Black Sea

    Science.gov (United States)

    Romaniello, S. J.; Brennecka, G.; Anbar, A. D.; Colman, A. S.

    2009-12-01

    The natural fractionation of long-lived uranium isotopes (238U, 235U) is being explored as a paleoredox proxy. While uranium behaves conservatively in oxic seawater, it is readily removed to sediments under reducing conditions. Measurements of δ238/235U in black shales and marine sediments deposited under sulfidic conditions suggest that uranium removed in such environments is isotopically heavy. However, this fractionation process has not been directly demonstrated in a present-day marine environment, nor is the specific mechanism of fractionation known. The euxinic water column of the Black Sea provides an ideal laboratory for studying uranium isotope fractionation. Uranium in Black Sea sediments is 0.35-0.84‰ heavy in δ238/235U relative to open ocean seawater (Weyer et al. 2008). We therefore expect that dissolved uranium in the Black Sea water column should be correspondingly light. Furthermore, direct measurements of δ238/235U versus depth could be used in combination with sediment δ238/235U to infer the dominant locations of U removal and constrain specific mechanisms of fractionation. Here we present the first δ238/235U depth profile from the water column of the Black Sea. The measurements were made on a Neptune MC-ICP-MS, using a 236U-233U double spike to correct for instrumental mass bias, following preconcentration and purification with UTEVA resin. With this method, we are able to measure δ238/235U with a 2σ precision of 0.07‰ on 100 ng samples. Our results show that δ238/235U decreases monotonically with depth (Fig. 1). At the surface, δ238/235U values are similar to those in the open ocean. At 2000m, δ238/235U is 0.28‰ lighter than open ocean seawater, while uranium concentrations are depleted by ~44% relative to conservative mixing. As expected, δ238/235U in the water column is always lighter than the underlying sediments, confirming that 238U is preferentially removed to marine sediments under sulfidic conditions. Fig 1. (left) Depth

  14. Reliability of using 238U/235U and 234U/238U ratios from alpha spectrometry as qualitative indicators of enriched uranium contamination.

    Science.gov (United States)

    Minteer, Mark; Winkler, Paul; Wyatt, Bill; Moreland, Scott; Johnson, Jamie; Winters, Tim

    2007-05-01

    Alpha spectrometry is a commonly used technique for the measurement of uranium isotopes in environmental samples because it is widely available at a relatively low cost. For natural uranium the (234)U to (238)U activity ratio should be 1 and the (238)U to (235)U activity ratio should be 21.7. However, a lower (238)U to (235)U ratio is usually observed in alpha spectrometric analysis of environmental soil samples. This observation has led to the conclusion that soils from nuclear weapons facilities were contaminated with highly enriched uranium. This study was undertaken to test the reliability of using activity ratios from alpha spectrometry to infer the presence of highly enriched uranium in soil samples. The results of these experiments indicate that the (238)U to (235)U activity ratio is not a reliable indicator, but that the (234)U to (238)U activity ratio can be used to qualitatively indicate the presence of highly enriched uranium at concentrations near 10 ng g(-1) and above.

  15. Primary liver tumors in beagle dogs exposed by inhalation to aerosols of plutonium-238 dioxide.

    Science.gov (United States)

    Gillett, N. A.; Muggenburg, B. A.; Mewhinney, J. A.; Hahn, F. F.; Seiler, F. A.; Boecker, B. B.; McClellan, R. O.

    1988-01-01

    Primary liver tumors developed in Beagle dogs exposed by inhalation to aerosols of 238PuO2. Initial deposition of 238PuO2 in the respiratory tract was followed by translocation of a portion of the 238Pu to the liver and skeleton, which resulted in a large dose commitment and tumor risk to all three tissues. In a population of 144 dogs exposed to 238PuO2, 112 dogs died or were killed 4000 days after 238Pu exposure, 100 dogs had osteosarcoma, and 28 dogs had lung cancers. At increasing times after exposure, however, liver lesions have become more pronounced. Ten primary liver tumors in nine animals were diagnosed in the dogs dying before 4000 days after exposure. An additional five primary liver tumors in three dogs occurred in 9 animals killed after 4000 days after exposure. The majority of these tumors have been fibrosarcomas. The liver tumors were usually not the cause of death, and rarely metastasized. The occurrence of liver tumors in this study indicates that 238Pu is an effective hepatic carcinogen. Liver carcinogenesis is assuming an increasing importance in this study at late times after inhalation exposure. These results suggest that the liver may be an important organ at risk for the development of neoplasia in humans at time periods long after inhalation of 238Pu. Images Figure 3 Figure 4 Figure 5 Figure 6 PMID:3142267

  16. 238U/235U systematics in terrestrial uranium-bearing minerals

    OpenAIRE

    Hiess, Joe; Daniel J. Condon; McLean, Noah; Noble, Stephen R.

    2012-01-01

    The present-day 238U/235U ratio has fundamental implications for uranium-lead geochronology and cosmochronology. A value of 137.88 has previously been considered invariant and has been used without uncertainty to calculate terrestrial mineral ages. We report high-precision 238U/235U measurements for a suite of uranium-bearing minerals from 58 samples representing a diverse range of lithologies. This data set exhibits a range in 238U/235U values of >5 per mil, with no clear relation to any pet...

  17. 8 CFR 1238.1 - Proceedings under section 238(b) of the Act.

    Science.gov (United States)

    2010-01-01

    ... alien in the alien's native language or in a language that the alien understands. (c) Alien's response... 238(b) of the Act. (a) Definitions. As used in this part the term: Deciding Service officer means a...

  18. Experimental determination of the antineutrino spectrum of the fission products of {sup 238}U

    Energy Technology Data Exchange (ETDEWEB)

    Haag, Nils-Holger

    2013-10-09

    Fission of {sup 238}U contributes about 10 % to the antineutrino emission of a pressurized water reactor. In the present thesis, the beta spectrum of the fission products of {sup 238}U was determined in an experiment at the neutron source FRM II. This beta spectrum was subsequently converted into an antineutrino spectrum. This first measurement of the antineutrino spectrum supports all current and future reactor antineutrino experiments.

  19. 49 CFR 238.119 - Rim-stamped straight-plate wheels.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Rim-stamped straight-plate wheels. 238.119 Section... Requirements § 238.119 Rim-stamped straight-plate wheels. (a)(1) Except as provided in paragraph (a)(2) of this... than a private car, that is equipped with a rim-stamped straight-plate wheel if a brake shoe acts on...

  20. Application of molten salt oxidation for the minimization and recovery of plutonium-238 contaminated wastes

    Energy Technology Data Exchange (ETDEWEB)

    Wishau, R.

    1998-05-01

    Molten salt oxidation (MSO) is proposed as a {sup 238}Pu waste treatment technology that should be developed for volume reduction and recovery of {sup 238}Pu and as an alternative to the transport and permanent disposal of {sup 238}Pu waste to the WIPP repository. In MSO technology, molten sodium carbonate salt at 800--900 C in a reaction vessel acts as a reaction media for wastes. The waste material is destroyed when injected into the molten salt, creating harmless carbon dioxide and steam and a small amount of ash in the spent salt. The spent salt can be treated using aqueous separation methods to reuse the salt and to recover 99.9% of the precious {sup 238}Pu that was in the waste. Tests of MSO technology have shown that the volume of combustible TRU waste can be reduced by a factor of at least twenty. Using this factor the present inventory of 574 TRU drums of {sup 238}Pu contaminated wastes is reduced to 30 drums. Further {sup 238}Pu waste costs of $22 million are avoided from not having to repackage 312 of the 574 drums to a drum total of more than 4,600 drums. MSO combined with aqueous processing of salts will recover approximately 1.7 kilograms of precious {sup 238}Pu valued at 4 million dollars (at $2,500/gram). Thus, installation and use of MSO technology at LANL will result in significant cost savings compared to present plans to transport and dispose {sup 238}Pu TRU waste to the WIPP site. Using a total net present value cost for the MSO project as $4.09 million over a five-year lifetime, the project can pay for itself after either recovery of 1.6 kg of Pu or through volume reduction of 818 drums or a combination of the two. These savings show a positive return on investment.

  1. 450,000 years of groundwater (234U/238U)0 variations in SW Nevada, USA

    Science.gov (United States)

    Wendt, Kathleen A.; Moseley, Gina E.; Pythoud, Mathieu; Dublyansky, Yuri; Edwards, R. Lawrence; Spötl, Christoph

    2017-04-01

    Subaqueous speleothems represent a unique archive for geochemical variations in regional groundwater systems. Devils Hole 2 cave, located in SW Nevada, USA, is an open fault zone intersecting the Ash Meadows groundwater flow system. Speleothem layers that coat the submerged walls of Devils Hole 2 cave record the isotopic composition of groundwater uranium at the time of precipitation. Past variations of 234U/238U initial activity ratios in groundwater may provide insight into paleohydrological conditions, such as changes to groundwater flow rates or source inputs. We aim to reconstruct 450 ka of groundwater (234U/238U)0 variations at Devils Hole 2 cave. To do so, an 80 cm-long core was drilled from the cave wall. Over 100 (234U/238U) and U-Th ages were measured in order to calculate initial activity ratios. Despite relatively constant uranium concentrations and growth rates throughout the core, preliminary results show a range in values (2.851 -2.616) deviating from modern day groundwater (234U/238U)0 which we measured to 2.762 (±0.002). (234U/238U)0 variations appear to follow interglacial-glacial cycles from 450 ka to present day, such that maximum (234U/238U)0 ratios identified at roughly 43, 185, 289, 374, and 449 ka correspond to glacial periods, while minimum (234U/238U)0 ratios at roughly 5, 121, 239, 336 and 422 ka correspond to interglacial periods. Focusing on the last 200 ka, we observe increasing (234U/238U)0 ratios coupled with depleted Devils Hole 2 δ18O values and water table high-stands (Moseley et al. 2016, Science 2016). We suggest that (234U/238U)0 variations are positively correlated to precipitation amount, contrary to dripstone speleothem records in the Great Basin region. Mechanisms driving the fluctuation in (234U/238U)0 values are still uncertain, but may be due to increased inputs of additional minor groundwater sources to the Ash Meadows flow system during pluvial periods.

  2. Californium-252 Program Equipment Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Chattin, Fred Rhea [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Kenton [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ezold, Julie G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-12-01

    To successfully continue the 252Cf production and meet the needs of the customers, a comprehensive evaluation of the Building 7920 processing equipment was requested to identify equipment critical to the operational continuity of the program.

  3. Adsorption of Cs-137 and U-238 in semi-arid soils; Adsorcion de Cs-137 y U-238 en suelos semiaridos

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez T, U. O. [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, 52140 Metepec, Estado de Mexico (Mexico); Monroy G, F.; Anguiano A, J. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Fernandez R, E., E-mail: uohtrejo@gmail.com [Universidad Politecnica del Valle de Toluca, Carretera Toluca-Almoloya de Juarez Km. 5.6, Santiaguito Tlalcilalcali, Estado de Mexico (Mexico)

    2013-10-15

    Is of great importance to determine the adsorption properties of the soils where radioactive wastes are stored, fundamentally of the radioisotopes contained in these wastes, with the purpose of knowing like will be their behavior in the event of happening radionuclide migration toward the surrounding means. Therefore, in this work the adsorption properties of {sup 137}Cs{sup +} and {sup 238}UO{sub 2}{sup 2+} in soils coming from the Storage Center of Radioactive Wastes are studied. Was studied the effect of the soil type and the particle size of the soil in the adsorption properties of Cs (I) and U (Vi). 13 soil samples and six different particle sizes were analyzed. The adsorption studies were carried out by the radiotracers technique in static way. The results indicate an important adsorption affinity toward the Cs-137 and a very vulnerable affinity for the {sup 238}UO{sub 2}{sup 2+}. (author)

  4. Hematological responses after inhaling {sup 238}PuO{sub 2}: An extrapolation from beagle dogs to humans

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.; Muggenburg, B.A.; Welsh, C.A.; Angerstein, D.A.

    1994-11-01

    The alpha emitter plutonium-238 ({sup 238}Pu), which is produced in uranium-fueled, light-water reactors, is used as a thermoelectric power source for space applications. Inhalation of a mixed oxide form of Pu is the most likely mode of exposure of workers and the general public. Occupational exposures to {sup 238}PuO{sub 2} have occurred in association with the fabrication of radioisotope thermoelectric generators. Organs and tissue at risk for deterministic and stochastic effects of {sup 238}Pu-alpha irradiation include the lung, liver, skeleton, and lymphatic tissue. Little has been reported about the effects of inhaled {sup 238}PuO{sub 2} on peripheral blood cell counts in humans. The purpose of this study was to investigate hematological responses after a single inhalation exposure of Beagle dogs to alpha-emitting {sup 238}PuO{sub 2} particles and to extrapolate results to humans.

  5. Transmission Nuclear Resonance Fluorescence Measurements of 238U in Thick Targets

    Energy Technology Data Exchange (ETDEWEB)

    Quiter, Brian J.; Ludewigt, Bernhard A.; Mozin, Vladimir V.; Wilson, Cody; Korbly, Steve

    2010-08-31

    Transmission nuclear resonance fluorescence measurements were made on targets consisting of Pb and depleted U with total areal densities near 86 g/cm2. The 238U content n the targets varied from 0 to 8.5percent (atom fraction). The experiment demonstrates the capability of using transmission measurements as a non-destructive technique to identify and quantify the presence of an isotope in samples with thicknesses comparable to he average thickness of a nuclear fuel assembly. The experimental data also appear to demonstrate the process of notch refilling with a predictable intensity. Comparison of measured spectra to previous backscatter 238U measurements indicates general agreement in observed excited states. Two new 238U excited states and possibly a third state have also been observed.

  6. 238PuO2 Fuel and Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, Douglas R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rawool-Sullivan, Mohini [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Garner, Scott Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wenz, Tracy R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-01

    238Pu is an ideal material for use as a heat source with its half-life of 87.7 years and copious particle emissions. 238Pu radioisotope thermoelectric generators (RTGs) have found use for pacemakers, Apollo Space missions, Mars rovers, and Voyager spacecraft. In evaluating the dose to personnel and components near a 238Pu-based RTG, a number of additional nuclides and their daughter products must be considered to get an accurate estimate for γ-dose, and the amount of 17O and 18O for the neutron-dose must be considered. This paper looks at the contributing nuclides and their daughter products that add the most to the dose rates.

  7. Application of a canine 238Pu dosimetry model to human bioassay data

    Energy Technology Data Exchange (ETDEWEB)

    Hickman, Jr., A. W. [Florida Univ., Gainesville, FL (United States)

    1991-08-01

    Associated with the use of 2238Pu in thermoelectric power sources for space probes and power supplies for cardiac devices is the potential for human exposure to 238Pu, primarily by inhalation. In the event of human internal exposure, a means is needed for assessing the level of intake and calculating radiation doses. Several bioassay/dosimetry models have been developed for 239Pu. However, results from studies with laboratory animals have indicated that the biokinetics, and therefore the descriptive models, of 238Pu are significantly different from those for 239Pu. A canine model accounting for these differences has been applied in this work to urinary excretion data from seven humans occupationally exposed to low levels of an insoluble 238Pu compound. The modified model provides a good description of the urinary excretion kinetics observed in the exposed humans. The modified model was also used to provide estimates of the initial intakes of 238Pu for the seven individuals; these estimates ranged from 4.5 nCi (170 Bq) to 87 nCi (3200 Bq). Autopsy data on the amount and distribution of 238Pu retained in the organs may be used in the future to validate or refute both these estimates and the assumptions used to formulate the human model. Modification of the human model to simulate an injection exposure to 239Pu gave patterns of retention in the organs and urinary excretion comparable to those seen previously in humans; further modification of the model using fecal data (unavailable for the subjects of this study) is indicated.

  8. Determination of the isotopic ratio {sup 234} U/{sup 238} U and {sup 235} U/{sup 238} U in uranium commercial reagents by alpha spectroscopy; Determinacion de la relacion isotopica {sup 234} U/{sup 238} U y {sup 235} U/{sup 238} U en reactivos comerciales de uranio por espectrometria alfa

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe G, J.L

    1990-02-15

    In this work the determination of the isotope ratio {sup 234} U/{sup 238} U and {sup 235} U/{sup 238} U obtained by means of the alpha spectroscopy technique in uranium reagents of commercial marks is presented. The analyzed uranium reagents were: UO{sub 2} (*) nuclear purity, UO{sub 3} (*) poly-science, metallic uranium, uranyl nitrate and uranyl acetate Merck, uranyl acetate and uranyl nitrate Baker, uranyl nitrate (*) of the Refinement and Conversion Department of the ININ, uranyl acetate (*) Medi-Lab Sigma of Mexico and uranyl nitrate Em Science. The obtained results show that the reagents that are suitable with asterisk (*) are in radioactive balance among the one {sup 234} U/{sup 238} U, since the obtained value went near to the unit. In the case of the isotope ratio {sup 235} U/{sup 238} U the near value was also obtained the one that marks the literature that is to say 0.04347, what indicates that these reagents contain the isotope of {sup 235} U in the percentage found in the nature of 0.71%. The other reagents are in radioactive imbalance among the {sup 234} U/{sup 238} U, the found values fluctuated between 0.4187 and 0.1677, and for the quotient of activities {sup 235} U/{sup 238} U its were of 0.0226, and the lowest of 0.01084. Also in these reagents it was at the {sup 236} U as impurity. The isotope of {sup 236} U is an isotope produced artificially, for what is supposed that the reagents that are in radioactive imbalance were synthesized starting from irradiated fuel. (Author)

  9. An Update on the Status of the Supply of Plutonium-238 for Future NASA Missions

    Science.gov (United States)

    Wham, R. M.

    2016-12-01

    For more than five decades, Radioisotope Power Systems (RPSs) have enabled space missions to operate in locations where the Sun's intensity is too weak, obscured, or otherwise inadequate for solar power or other conventional power‒generation technologies. The natural decay heat (0.57 W/g) from the radioisotope, plutonium-238 (238Pu), provides the thermal energy source used by an RPS to generate electricity for operation of instrumentation, as well as heat to keep key subsystems warm for missions such as Voyagers 1 and 2, the Cassini mission to Saturn, the New Horizons flyby of Pluto, and the Mars Curiosity rover which were sponsored by the National Aeronautics and Space Administration (NASA). Plutonium-238 is produced by irradiation of neptunium-237 in a nuclear reactor a relatively high neutron flux. The United States has not produced new quantities of 238Pu since the early 1990s. RPS‒powered missions have continued since then using existing 238Pu inventory managed by the U.S. Department of Energy (DOE), including material purchased from Russia. A new domestic supply is needed to ensure the continued availability of RPSs for future NASA missions. NASA and DOE are currently executing a project to reestablish a 238Pu supply capability using its existing facilities and reactors, which are much smaller than the large-scale production reactors and processing canyon equipment used previously. The project is led by the Oak Ridge National Laboratory (ORNL). Target rods, containing NpO2, will be fabricated at ORNL and irradiated in the ORNL High Flux Isotope Reactor and the Advanced Test Reactor at Idaho National Laboratory. Irradiated targets will be processed in chemical separations at the ORNL Radiochemical Engineering Center to recover the plutonium product and unconverted neptunium for recycle. The 238PuO2 product will be shipped to Los Alamos National Laboratory for fabrication of heat source pellets. Key activities, such as transport of the neptunium to ORNL

  10. Evidence for multiphonon giant resonances in electromagnetic fission of 238U.

    Science.gov (United States)

    Ilievski, S; Aumann, T; Boretzky, K; Elze, Th W; Emling, H; Grünschloss, A; Holeczek, J; Holzmann, R; Kozhuharov, C; Kratz, J V; Kulessa, R; Leistenschneider, A; Lubkiewicz, E; Ohtsuki, T; Reiter, P; Simon, H; Stelzer, K; Stroth, J; Sümmerer, K; Wajda, E; Waluś, W

    2004-03-19

    Differential cross sections for electromagnetic fission of 238U projectiles (500 MeV/u) in C, Sn, and Pb targets are measured and analyzed in terms of single- and multiphonon giant resonance excitations as doorway states to fission. A novel experimental method exploits the linear relationship between neutron multiplicity and the primary 238U excitation energy. Multiphonon states contribute up to 20% of the cross section; a component at high excitation energies is indicated that may arise from three-phonon dipole and two-phonon GDR x GQRiv giant resonance excitations.

  11. 76 FR 53851 - Federal Housing Administration (FHA): Suspension of Section 238(c) Single-Family Mortgage...

    Science.gov (United States)

    2011-08-30

    ... construction, repair, rehabilitation, or purchase of property located near any installation of the Armed Forces... Section 238(c) Single-Family Mortgage Insurance in Military Impacted Areas AGENCY: Office of the Assistant... National Housing Act (Act). This single-family mortgage insurance program, established by regulation in...

  12. 29 CFR 779.238 - Engagement in described activities determined on annual basis.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Engagement in described activities determined on annual... FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Employment to Which the Act May Apply; Enterprise Coverage Covered Enterprises § 779.238 Engagement in described activities determined...

  13. Pharmacological activity of 2,3,8-tri-O-methyl ellagic acid isolated ...

    African Journals Online (AJOL)

    SERVER

    2007-08-20

    Aug 20, 2007 ... Full Length Research Paper. Pharmacological activity of 2,3,8-tri-O-methyl ellagic acid isolated from the stem bark of Irvingia gabonensis. George, I. Ndukwe 1* and Yimin Zhao2. 1Department of Chemistry, Ahmadu Bello University, Zaria, Nigeria. 2Beijing Institute of Pharmacology and Toxicology, Beijing, ...

  14. Enhanced nucleon transfer in tip collisions of 238U+124Sn

    Science.gov (United States)

    Sekizawa, Kazuyuki

    2017-10-01

    Multinucleon transfer processes in low-energy heavy ion reactions have attracted increasing interest in recent years aiming at the production of new neutron-rich isotopes. Clearly, it is an imperative task to further develop understanding of underlying reaction mechanisms to lead experiments to success. In this paper, from systematic time-dependent Hartree-Fock calculations for the 238U+124Sn reaction, it is demonstrated that transfer dynamics depend strongly on the orientations of 238U, quantum shells, and collision energies. Two important conclusions are obtained: (i) Experimentally observed many-proton transfer from 238U to 124Sn can be explained by a multinucleon transfer mechanism governed by enhanced neck evolution in tip collisions; (ii) novel reaction dynamics are observed in tip collisions at energies substantially above the Coulomb barrier, where a number of nucleons are transferred from 124Sn to 238U, producing transuranium nuclei as primary reaction products, which could be a means to synthesize superheavy nuclei. Both results indicate the importance of the neck (shape) evolution dynamics, which are sensitive to orientations, shell effects, and collision energies, for exploring possible pathways to produce new unstable nuclei.

  15. The enigma of the ν=2+3/8 fractional quantum Hall effect

    DEFF Research Database (Denmark)

    Hutasoit, Jimmy; nrc762, nrc762; Mukherjee, Sutirtha

    2017-01-01

    The fractional quantum Hall effect at ν=2+3/8, which has been definitively observed, is one of the last fractions for which no viable explanation has so far been demonstrated. Our detailed study suggests that it belongs to a new class of exotic states described by the Bonderson-Slingerland wave...

  16. 49 CFR 238.419 - Truck-to-car-body and truck component attachment.

    Science.gov (United States)

    2010-10-01

    ... (which include axles, wheels, bearings, the truck-mounted brake system, suspension system components, and... 49 Transportation 4 2010-10-01 2010-10-01 false Truck-to-car-body and truck component attachment... Specific Requirements for Tier II Passenger Equipment § 238.419 Truck-to-car-body and truck component...

  17. Energy dependence of 238U fission yields investigated in inverse kinematics

    Directory of Open Access Journals (Sweden)

    Veselsky M.

    2010-03-01

    Full Text Available The production cross sections of neutron-rich fission residues produced in reactions induced by a 238U beam impinging onto Pb and Be targets were investigated at the Fragment Separator (FRS at GSI using the inverse kinematic technique. These data allowed us to discuss the optimum energies in fission for producing the most neutron-rich residues.

  18. New explanation for extreme u-234 u-238 disequilibria in a dolomitic aquifer

    CSIR Research Space (South Africa)

    Kronfeld, J

    1994-05-01

    Full Text Available High U-234/U-238 activity ratios are found in the shallow groundwater of the phreatic Transvaal Dolomite Aquifer. The aquifer is uranium poor, while the waters are oxygen rich and young. Tritium and C-14 are used to show that the disequilibrium...

  19. Reaction paths and host phases of uranium isotopes (235U; 238U), Saanich Inlet

    Science.gov (United States)

    Amini, M.; Holmden, C. E.; Francois, R. H.

    2009-12-01

    In recent times, Uranium has become increasingly the focus of stable isotope fractionation studies. Variations in 238U/235U have been reported as a result of redox reactions [1,2] from the nuclear field shift effect [3], and a mass-dependent, microbially-mediated, kinetic isotope effect [4]. The 238U/235U variability caused by changes in environmental redox conditions leads to an increase in the 238U/235U ratios of the reduced U species sequestered into marine sediments. This points to U isotope variability as a new tool to study ancient ocean redox changes. However, the process by which reduced sediments become enriched in the heavy isotopes of U is not yet known, and hence the utility of 238U/235U as a redox tracer remains to be demonstrated. In order to further constrain sedimentary U enrichment and related isotope effect, we are investigating U isotopic compositions of water samples and fresh surface sediment grab samples over a range of redox conditions in the seasonally anoxic Saanich Inlet, on the east coast of Vancouver Island. U was sequentially extracted from sediments in order to characterize specific fractions for their isotopic composition. The measurements were carried out by MC-ICPMS using 233U/236U-double spike technique. The data are reported as δ238U relative to NBL 112a with a 238U/235U ratio of 137.88 (2sd). External precision is better than 0.10‰ (2sd). Fifteeen analyses of seawater yielded δ238U of -0.42±0.08‰ (2sd). The results for the water samples indicate a homogenous δ238U value throughout the Saanich Inlet water column that matches the global seawater signature. All of the water samples from above and below average -0.42±0.05‰ (2sd). In contrast, a plankton net sample yielded a distinctly different, (about 0.5‰ lighter) isotope value. Bacterial reduction experiments [4] have also shown isotope enrichment factors of about -0.3‰. In addition, metal isotope fractionation occurs during adsorption with the light isotope being

  20. Manganese determination om minerals by activation analysis, using the californium-252 as a neutron source; Determinacao de manganes em minerios, por analise por ativacao, usando californio-252 como fonte de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Antonio

    1976-07-01

    Neutron Activation Analysis, using a Californium-252 neutron source, has been applied for the determination of manganese in ores such as pyrolusite, rodonite (manganese silicate)' and blending used in dry-batteries The favorable nuclear properties of manganese, such as high thermal neutron cross-section for the reaction {sup 55}Mn (n.gamma){sup 56} Mn, high concentration of manganese in the matrix and short half - life of {sup 56}Mn, are an ideal combination for non-destructive analysis of manganese in ores. Samples and standards of manganese dioxide were irradiated for about 20 minutes, followed by a 4 to 15 minutes decay and counted in a single channel pulse-height discrimination using a NaI(Tl) scintillation detector. Counting time was equal to 10 minutes. The interference of nuclear reactions {sup 56}Fe(n,p){sup 56}Mn and {sup 59} Co (n, {alpha}){sup 56} were studied, as well as problems in connection with neutron shadowing during irradiation, gamma-rays attenuation during counting and influence of granulometry of samples. One sample,was also analysed by wet-chemical method (sodium bismuthate) in order to compare results. As a whole, i t was shown that the analytical method of neutron activation for manganese in ores and blending, is a method simple, rapid and with good precision and accuracy. (author)

  1. Design of a homogeneous subcritical nuclear reactor based on thorium with a source of californium 252; Diseno de un reactor nuclear subcritico homogeneo a base de Torio con una fuente de Californio 252

    Energy Technology Data Exchange (ETDEWEB)

    Delgado H, C. E.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Sajo B, L., E-mail: ce_delgado89@hotmail.com [Universidad Simon Bolivar, Laboratorio de Fisica Nuclear, Apdo. 89000, 1080A Caracas (Venezuela, Bolivarian Republic of)

    2015-10-15

    Full text: One of the energy alternatives to fossil fuels which do not produce greenhouse gases is the nuclear energy. One of the drawbacks of this alternative is the generation of radioactive wastes of long half-life and its relation to the generation of nuclear materials to produce weapons of mass destruction. An option to these drawbacks of nuclear energy is to use Thorium as part of the nuclear fuel which it becomes in U{sup 233} when capturing neutrons, that is a fissile material. In this paper Monte Carlo methods were used to design a homogeneous subcritical reactor based on thorium. As neutron reflector graphite was used. The reactor core is homogeneous and is formed of 70% light water as moderator, 12% of enriched uranium UO{sub 2}(NO{sub 3}){sub 4} and 18% of thorium Th(NO{sub 3}){sub 4} as fuel. To start the nuclear fission chain reaction an isotopic source of californium 252 was used with an intensity of 4.6 x 10{sup 7} s{sup -1}. In the design the value of the effective multiplication factor, whose value turned out k{sub eff} <1 was calculated. Also, the neutron spectra at different distances from the source and the total fluence were calculated, as well as the values of the ambient dose equivalent in the periphery of the reactor. (Author)

  2. 24 CFR 1000.238 - What percentage of the IHBG funds can be used for administrative and planning expenses?

    Science.gov (United States)

    2010-04-01

    ... can be used for administrative and planning expenses? 1000.238 Section 1000.238 Housing and Urban... administrative and planning expenses? The recipient can use up to 20 percent of its annual grant amount for administration and planning. The recipient shall identify the percentage of grant funds which will be used in the...

  3. Inhibition of the UCI-107 human ovarian carcinoma cell line by a targeted cytotoxic analog of somatostatin, AN-238.

    Science.gov (United States)

    Plonowski, A; Schally, A V; Koppan, M; Nagy, A; Arencibia, J M; Csernus, B; Halmos, G

    2001-09-01

    Cytotoxic analogs of somatostatin (SST), such as AN-238, which consists of 2-pyrrolinodoxorubicin (AN-201) linked to the SST carrier RC-121, can be targeted to tumors that express SST receptors. Because SST receptors are present in ovarian carcinoma cells, the authors evaluated the effect of AN-238 on the UCI-107 ovarian carcinoma cell line. An analysis of microsatellite alleles in cocultured SST receptor positive and receptor negative cells was used for the demonstration of in vitro targeting. The toxicity and antitumor effects of AN-238 in nude mice bearing UCI-107 human ovarian tumors were investigated with or without pharmacologic inhibition of serum carboxylesterases (CE). The expression of SST receptor subtypes was determined by reverse transcriptase-polymerase chain reaction analysis, and the binding affinity of AN-238 to SST receptors was determined by radioligand assays. The proliferation of SST receptor positive UCI-107 cells in vitro was inhibited preferentially by AN-238. AN-238 showed high-affinity binding to UCI-107 tumor membranes at a 50% inhibition concentration of 3.39 nM +/- 0.74 nM. In vivo, the volume and weights of UCI-107 tumors treated with AN-238 were decreased by more than 60% (P < 0.05) compared with controls. Cytotoxic radical AN-201 or the unconjugated mixture of AN-201 with carrier RC-121 had no significant effects on tumors and were toxic. In mice with inhibited serum CE activity, AN-201 at 400 nmol/kg was lethal, whereas AN-238 at a total dose of 800 nmol/kg caused only 22% mortality and reduced tumor weight by 69% and volume by 70% (P < 0.05 vs. control). Targeted chemotherapy with the SST conjugate AN-238 inhibits SST receptor positive experimental ovarian tumors. AN-238 may provide a new treatment modality for patients with advanced ovarian carcinoma. Copyright 2001 American Cancer Society.

  4. Natural Variation of 238U/235U in Geo- and Cosmochemistry

    Science.gov (United States)

    Weyer, S.; Brennecka, G.; Montoya Pino, C.; Noordmann, J.; Schauble, E. A.; Wadhwa, M.; Anbar, A. D.

    2009-12-01

    The ratio of the two primordial U isotopes has long been assumed to be invariant (i.e. 238U/235U = 137.88, [1]) in the Solar [1, 2]. Due to analytical improvements, small (‰-range) U isotope variations can now be detected in both terrestrial [3, 4, 5] and meteoritic materials [6]. Uranium isotope variations on Earth are produced by chemical reactions, analogous to stable isotope fractionation, although U has no stable isotopes. The range of U isotope variations observed thus far on Earth exceeds 1‰ and is mostly driven by nuclear field shift effects, which depend on nuclear volume rather than mass [7]. The strongest isotope fractionation appears to occur between oxidized and reduced U species (UVI and UIV). As a result, oxic environments (e.g., seawater) are enriched in the light U isotope, 235U, while anoxic sediments (e.g., from the Black Sea) are enriched in the heavy U isotope, 238U [4]. This redox-sensitive behavior of U isotope compositions makes the 238U/235U ratio promising for use as a paleo-redox proxy. In paleoceanography, 238U/235U ratios can be used to estimate the extent of seafloor anoxia. During periods of enhanced global ocean anoxia (e.g., during the mid-Cretaceous oceanic anoxic event OAE-2) heavy U was preferentially buried into anoxic sediments. Accordingly, sea water and all oceanic sinks became depleted in heavy U. We used this shift in U isotope compositions to estimate a three times enhancement of anoxic environments in the oceans during OAE-2 compared to today [8]. In meteoritic materials, 238U/235U variations may be produced by (1) chemical reactions (2) nucleosynthetic anomalies and/or (3) decay of the short-lived extant 247Cm (half life = 15.6 Ma) to 235U. We investigated the U isotope composition of calcium aluminum-rich inclusions (CAIs). The Pb-Pb ages of CAIs define the age of the Solar System, as they represent the first solids to condense from the cooling protoplanetary disk. The investigated CAIs from the Allende meteorite

  5. Solubility of 238U radionuclide from various types of soil in synthetic gastrointestinal fluids using "US in vitro" digestion method

    Science.gov (United States)

    Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

    2015-04-01

    238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by "US P in vitro" digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 - 0.209 ppm) than gastrointestinal fluids (0.024 - 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

  6. Measurement of neutron inelastic scattering cross section of {sup 238}U

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Takako; Baba, Mamoru; Ibaraki, Masanobu; Sanami, Toshiya; Win, Than; Hirasawa, Yoshitaka; Matsuyama, Shigeo; Hirakawa, Naohiro [Tohoku Univ., Sendai (Japan)

    1998-03-01

    Neutron scattering from the 0{sup +}, 2{sup +} (1-st) and 4{sup +} (2nd) levels of {sup 238}U was measured for incident energies between 0.4 and 0.85 MeV at the Tohoku University 4.5 MV Dynamitron facility, using the time-of-flight (TOF) method with monoenergetic pulsed neutrons by the {sup 7}Li(p,n) reaction. The results are presented in comparison with other experimental data and evaluated data. (author)

  7. Absolute measurement of rates of capture of neutrons in 238U and fission in 239Pu

    Science.gov (United States)

    Dulin, V. A.

    1981-04-01

    The absolute rate of capture of neutrons in U-238 was measured in terms of the Np-239 activity found (gamma radiation), using a calibrated Am-243 source to determine the efficiency of gamma recording in the detector. The absolute rate of fission of Pu-239 was determined by means of a fission chamber with a known number of Pu-239 nuclei, and the efficiency of fission fragment recording in the chamber was calculated.

  8. Beta decay heat following U-235, U-238 and Pu-239 neutron fission

    Science.gov (United States)

    Li, Shengjie

    1997-09-01

    This is an experimental study of beta-particle decay heat from 235U, 239Pu and 238U aggregate fission products over delay times 0.4-40,000 seconds. The experimental results below 2s for 235U and 239Pu, and below 20s for 238U, are the first such results reported. The experiments were conducted at the UMASS Lowell 5.5-MV Van de Graaff accelerator and 1-MW swimming-pool research reactor. Thermalized neutrons from the 7Li(p,n)7Be reaction induced fission in 238U and 239Pu, and fast neutrons produced in the reactor initiated fission in 238U. A helium-jet/tape-transport system rapidly transferred fission fragments from a fission chamber to a low background counting area. Delay times after fission were selected by varying the tape speed or the position of the spray point relative to the beta spectrometer that employed a thin-scintillator-disk gating technique to separate beta-particles from accompanying gamma-rays. Beta and gamma sources were both used in energy calibration. Based on low-energy(<1 MeV) internal-conversion electron studies, a set of trial responses for the spectrometer was established and spanned electron energies 0-10 MeV. Measured beta spectra were unfolded for their energy distributions by the program FERD, and then compared to other measurements and summation calculations based on ENDF/B-VI fission-product data performed on the LANL Cray computer. Measurements of the beta activity as a function of decay time furnished a relative normalization. Results for the beta decay heat are presented and compared with other experimental data and the summation calculations.

  9. 234U/238U as a ground-water tracer, SW Nevada-SE California

    Science.gov (United States)

    Ludwig, K. R.; Peterman, Z.E.; Simmons, K.R.; Gutentag, E.D.

    1993-01-01

    The 234U/238U ratio of uranium in oxidizing ground waters is potentially an excellent ground-water tracer because of its high solubility and insensitivity to chemical reactions. Moreover, recent advances in analytical capability have made possible very precise uranium-isotopic analyses on modest (approx.100 ml) amounts of normal ground water. Preliminary results on waters from SW Nevada/Se California indicate two main mixing trends, but in detail indicate significant complexity requiring three or more main components.

  10. 49 CFR Appendix A to Part 238 - Schedule of Civil Penalties 1

    Science.gov (United States)

    2010-10-01

    ...,000 7,500 (e) Failure to follow restrictions for inoperative front or rear unit 2,500 5,000 238... status 2,500 5,000 (d) Emergency back-up power 2,500 5,000 (f) End door kick-out panel or pop-out window...) Failure to inspect or improper use of roller bearings 2,500 5,000 (e) Improper movement of defective...

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

  12. Research on the reliability of measurement of natural radioactive nuclide concentration of U-238

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Seok Ki; Kim, Gee Hyun [Dept. of Nuclear engineering, Univ. of SeJong, Seoul (Korea, Republic of); Joo, Sun Dong; Lee, Hoon [KoFONS, Seongnam (Korea, Republic of)

    2016-12-15

    Naturally occurred radioactive materials (NORM) can be found all around us and people are exposed to this no matter what they do or where they live. In this study, two indirect measurement methods of NORM U-238 has been reviewed; one that has used HPGe on the basis of the maintenance, and the other is disequilibrium theory of radioactive equilibrium relationships of mother and daughter nuclide at Decay-chain of NORM U-238. For this review, complicated pre-processing process (Breaking->Fusion->Chromatography->Electron deposit) has been used , and then carried out a comparative research with direct measurement method that makes use of and measures Alpha spectrometer. Through the experiment as above, we could infer the daughter nuclide whose radioactive equilibrium has been maintained with U-238. Therefore, we could find out that the daughter nuclide suitable to be applied to Gamma indirect measurement method was Th-234. Due to Pearson Correlation statistics, we could find out the reliability of the result value that has been analyzed by using Th-234.

  13. Validation of the U-238 inelastic scattering neutron cross section through the EXCALIBUR dedicated experiment

    Science.gov (United States)

    Leconte, Pierre; Bernard, David

    2017-09-01

    EXCALIBUR is an integral transmission experiment based on the fast neutron source produced by the bare highly enriched fast burst reactor CALIBAN, located in CEA/DAM Valduc (France). Two experimental campaigns have been performed, one using a sphere of diameter 17 cm and one using two cylinders of 17 cm diameter 9 cm height, both made of metallic Uranium 238. A set of 15 different dosimeters with specific threshold energies have been employed to provide information on the neutron flux attenuation as a function of incident energy. Measurements uncertainties are typically in the range of 0.5-3% (1σ). The analysis of these experiments is performed with the TRIPOLI4 continuous energy Monte Carlo code. A calculation benchmark with validated simplifications is defined in order to improve the statistical convergence under 2%. Various 238U evaluations have been tested: JEFF-3.1.1, ENDF/B-VII.1 and the IB36 evaluation from IAEA. A sensitivity analysis is presented to identify the contribution of each reaction cross section to the integral transmission rate. This feedback may be of interest for the international effort on 238U, through the CIELO project.

  14. 49 CFR Figure 1a to Subpart B of... - Example of Location of Rescue Access Windows-§ 238.114

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Example of Location of Rescue Access Windows-§ 238.114 1A Figure 1A to Subpart B of Part 238 Transportation Other Regulations Relating to... B of Part 238—Example of Location of Rescue Access Windows—§ 238.114 ER01FE08.002 [73 FR 6403, Feb...

  15. Isotopic production cross sections and kinematics of spallation residues from the reaction {sup 238}U(1 AGeV) + d

    Energy Technology Data Exchange (ETDEWEB)

    Casarejos, E.; Pereira, J.; Benlliure, J. [Universidade de Santiago de Compostela (Spain); Armbruster, P.; Enqvist, T.; Schmidt, K.H.; Taieb, J. [Gesellschaft fur Schwerionenforschung, Darmstadt (Germany); Bernas, M.; Mustapha, B.; Rejmund, F.; Stephan, C.; Tassan-Got, L. [Institut de Physique Nucleaire, 91 -Orsay (France); Boudard, A.; Leray, S.; Volant, C.; Wlazlo, W. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules de Physique Nucleaire et de l' Instrumentation Associee(DAPNIA-SPhN), 91- Gif sur Yvette (France)

    2008-07-01

    Isotopic production cross sections and momentum distributions of more than 1400 residual nuclei produced in the collision of {sup 238}U(1 AGeV)+{sup 2}H have been measured. The experiment was performed at GSI where we could take profit of the inverse kinematics technique and the high-resolution magnetic spectrometer FRS to identify in atomic and mass numbers all the produced nuclei. The identification technique challenges for the case of {sup 238}U are reviewed. Some features of {sup 238}U residues are discussed, including the access to information of fission dynamics. (authors)

  16. PROPERTIES AND BEHAVIOR OF 238PU RELEVANT TO DECONTAMINATION OF BUILDING 235-F

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, A.; Kane, M.

    2009-11-24

    This report was prepared to document the physical, chemical and radiological properties of plutonium oxide materials that were processed in the Plutonium Fuel Form Facility (PuFF) in building 235-F at the Savannah River Plant (now known as the Savannah River Site) in the late 1970s and early 1980s. An understanding of these properties is needed to support current project planning for the safe and effective decontamination and deactivation (D&D) of PuFF. The PuFF mission was production of heat sources to power Radioisotope Thermoelectric Generators (RTGs) used in space craft. The specification for the PuO{sub 2} used to fabricate the heat sources required that the isotopic content of the plutonium be 83 {+-} 1% Pu-238 due to its high decay heat of 0.57 W/g. The high specific activity of Pu-238 (17.1 Ci/g) due to alpha decay makes this material very difficult to manage. The production process produced micron-sized particles which proved difficult to contain during operations, creating personnel contamination concerns and resulting in the expenditure of significant resources to decontaminate spaces after loss of material containment. This report examines high {sup 238}Pu-content material properties relevant to the D&D of PuFF. These relevant properties are those that contribute to the mobility of the material. Physical properties which produce or maintain small particle size work to increase particle mobility. Early workers with {sup 238}PuO{sub 2} felt that, unlike most small particles, Pu-238 oxide particles would not naturally agglomerate to form larger, less mobile particles. It was thought that the heat generated by the particles would prevent water molecules from binding to the particle surface. Particles covered with bound water tend to agglomerate more easily. However, it is now understood that the self-heating effect is not sufficient to prevent adsorption of water on particle surfaces and thus would not prevent agglomeration of particles. Operational

  17. Generation of 238U Covariance Matrices by Using the Integral Data Assimilation Technique of the CONRAD Code

    Directory of Open Access Journals (Sweden)

    Privas E.

    2016-01-01

    Full Text Available A new IAEA Coordinated Research Project (CRP aims to test, validate and improve the IRDF library. Among the isotopes of interest, the modelisation of the 238U capture and fission cross sections represents a challenging task. A new description of the 238U neutrons induced reactions in the fast energy range is within progress in the frame of an IAEA evaluation consortium. The Nuclear Data group of Cadarache participates in this effort utilizing the 238U spectral indices measurements and Post Irradiated Experiments (PIE carried out in the fast reactors MASURCA (CEA Cadarache and PHENIX (CEA Marcoule. Such a collection of experimental results provides reliable integral information on the (n,γ and (n,f cross sections. This paper presents the Integral Data Assimilation (IDA technique of the CONRAD code used to propagate the uncertainties of the integral data on the 238U cross sections of interest for dosimetry applications.

  18. Plutonium-238 alpha-decay damage study of the ceramic waste form.

    Energy Technology Data Exchange (ETDEWEB)

    Frank, S M [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Barber, T L [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Cummings, D G [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; DiSanto, T [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Esh, D W [U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; Giglio, J J [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Goff, K M [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Johnson, S G [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Kennedy, J R [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Jue, J-F [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Noy, M [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; O' Holleran, T P [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Sinkler, W [UOP LLC, 25 E Algonquin Road, Des Plaines, IL 60017

    2006-03-27

    An accelerated alpha-decay damage study of a glass-bonded sodalite ceramic waste form has recently been completed. The purpose of this study was to investigate the physical and chemical durability of the waste form after significant exposure to alpha decay. This accelerated alpha-decay study was performed by doping the ceramic waste form with {sup 238}Pu which has a much greater specific activity than {sup 239}Pu that is normally present in the waste form. The alpha-decay dose at the end of the four year study was approximately 1 x 10{sup 18} alpha-decays/gram of material. An equivalent time period for a similar dose of {sup 239}Pu would require approximately 1100 years. After four years of exposure to {sup 238}Pu alpha decay, the investigation observed little change to the physical or chemical durability of the ceramic waste form (CWF). Specifically, the {sup 238}Pu-loaded CWF maintained it's physical integrity, namely that the density remained constant and no cracking or phase de-bonding was observed. The materials chemical durability and phase stability also did not change significantly over the duration of the study. The only significant measured change was an increase of the unit-cell lattice parameters of the plutonium oxide and sodalite phases of the material and an increase in the release of salt components and plutonium of the waste form during leaching tests, but, as mentioned, these did not lead to any overall loss of waste form durability. The principal findings from this study are: (1) {sup 238}Pu-loaded CWF is similar in microstructure and phase composition to referenced waste form. (2) Pu was observed primarily as oxide comprised of aggregates of nano crystals with aggregates ranging in size from submicron to twenty microns in diameter. (3) Pu phases were primarily found in the intergranular glassy regions. (4) PuO phase shows expected unit cell volume expansion due to alpha decay damage of approximately 0.7%, and the sodalite phase unit cell

  19. Deconvolution of 238,239,240Pu conversion electron spectra measured with a silicon drift detector.

    Science.gov (United States)

    Pommé, S; Marouli, M; Paepen, J; Marković, N; Pöllänen, R

    2017-09-13

    Internal conversion electron (ICE) spectra of thin 238,239,240Pu sources, measured with a windowless Peltier-cooled silicon drift detector (SDD), were deconvoluted and relative ICE intensities were derived from the fitted peak areas. Corrections were made for energy dependence of the full-energy-peak counting efficiency, based on Monte Carlo simulations. A good agreement was found with the theoretically expected internal conversion coefficient (ICC) values calculated from the BrIcc database. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Attempt to confirm superheavy element production in the 48Ca +238U reaction

    Energy Technology Data Exchange (ETDEWEB)

    Gregorich, K.E.; Loveland, W.; Peterson, D.; Zielinski, P.M.; Nelson, S.L.; Chung, Y.H.; Dullmann, Ch.E.; Folden III, C.M.; Aleklett,K.; Eichler, R.; Hoffman D.C.; Omtvedt, J.P.; Pang, G.K.; Schwantes,J.M.; Soverna, S.; Sprunger, P.; Sudowe, R.; Wilson, R.E.; Nitsche, H.

    2005-03-24

    An attempt to confirm production of superheavy elements in the reaction of 48Ca beams with actinide targets has been performed using the 238U(48Ca,3n)283112 reaction. Two 48Ca projectile energies were used, that spanned the energy range where the largest cross sections have been reported for this reaction. No spontaneous fission events were observed. No alpha decay chains consistent with either reported or theoretically predicted element 112 decay properties were observed. The cross section limits reached are significantly smaller than the recently reported cross sections.

  1. Temporal Variations in 234U/238U Activity Ratios in Four Mississippi River Tributaries

    Science.gov (United States)

    Grzymko, T. J.; Marcantonio, F.

    2005-05-01

    In 2004 we sampled the four tributaries that are the major contributors to the Mississippi River in terms of water discharge, i.e., the Arkansas, Missouri, Upper Mississippi, and Ohio rivers. Each river was sampled four times over the course of the year at variable levels of discharge in an attempt to constrain the causes of the temporal variations of 234U/238U activity ratios in the lower Mississippi River at New Orleans. The tributary uranium data support the idea that lower river uranium isotope and elemental systematics are controlled by a simple mass balance of the source tributary discharges. Furthermore, the uranium isotope ratios of the individual tributaries show coherent patterns of variability. Specifically, the data obtained from the four sampling trips yielded similar patterns of temporal variation in the 234U/238U activity ratios of all of the rivers, although the absolute values of these ratios were distinctly different from one river to the next. The pattern was such that the highest 234U/238U activity ratios were observed during the highest flow associated with the spring freshet while the lowest ratios occurred during the summer. For example, in the Missouri River, the 234U/238U activity ratios varied from 1.51 (February 12) to 1.37 (April 14) to 1.34 (July 16) to 1.37 (November 12), while in the Ohio River the same ratios varied from 1.36 (February 12) to 1.29 (April 14) to 1.21 (July 16) to 1.23 (November 12). The apparent seasonal pattern of these ratios in each tributary has led to several ideas as to the causes of the observed trends. The first, and most obvious, is that in each individual drainage basin there are various source tributaries that contribute to the uranium isotope systematics of the main stem of the tributary of interest. It follows that the variations in the uranium activity ratios may be caused by spatial variations in the source rock chemistry of the drainage basin. Other more complex scenarios can also be envisioned and

  2. Fractionation of 238U/235U in rivers and hydrothermal systems: Constraints for the oceanic U isotope cycle

    Science.gov (United States)

    Noordmann, J.; Weyer, S.; Sharma, M.; Georg, R.; Rausch, S.; Bach, W.

    2010-12-01

    Recently, fractionation of 238U/235U has been observed between oxic and anoxic oceanic environments (Weyer et al., 2008). Sedimentary deposits that formed under oxic conditions (containing U+6) are typically enriched in 235U and anoxic or euxinic sediments (containing U+4) typically show enrichment in 238U. These findings are in agreement with theoretical modeling by Schauble (2007) predicting that U isotope fractionation is dominated by volume-dependent effects. To constrain redox evolution of the oceans (Montoya-Pino et al., 2010), we need detailed information on the U isotope mass balance. However, U isotope fractionation during continental weathering and transport to the oceans, as well as during hydrothermal alteration (the second most important sink for U) is yet unknown. To constrain the isotope composition of the dominant U source to the oceans, we investigated water samples from rivers of different climatic conditions. To obtain an estimate on the U isotope composition of the hydrothermal sink, we analyzed five different hydrothermal fluids from the Juan de Fuca Ridge and, additionally, altered oceanic crust from the Bermuda Rise, Reykjanes Ridge and Pigafetta Basin. Furthermore, δ238U has been measured for granites of different localities and ages to expand the very limited data set for samples from the continental crust. Large rivers display an average δ238U of -0.24 ‰ (relative to CRM-112A) which is very similar to the average value of granites (δ238U= -0.30 ‰) and basalts (δ238U= -0.28 ‰), indicating that in average only minor U isotope fractionation occurs during weathering and transport. Only smaller rivers display larger U isotope variations (between 0.01 and -0.28 ‰) likely monitoring U isotope variations of their bed rocks. The hydrothermal waters display a tight range of δ238U (-0.32 and -0.54 ‰) around the seawater value of δ238U= -0.41 ‰ (Weyer et al., 2008), however, at much lower U concentration levels (0.08 to 0.24 ppb

  3. Depth profile of 236U/238U in soil samples in La Palma, Canary Islands

    Science.gov (United States)

    Srncik, M.; Steier, P.; Wallner, G.

    2011-01-01

    The vertical distribution of the 236U/238U isotopic ratio was investigated in soil samples from three different locations on La Palma (one of the seven Canary Islands, Spain). Additionally the 240Pu/239Pu atomic ratio, as it is a well establish tool for the source identification, was determined. The radiochemical procedure consisted of a U separation step by extraction chromatography using UTEVA® Resin (Eichrom Technologies, Inc.). Afterwards Pu was separated from Th and Np by anion exchange using Dowex 1x2 (Dow Chemical Co.). Furthermore a new chemical procedure with tandem columns to separate Pu and U from the matrix was tested. For the determination of the uranium and plutonium isotopes by alpha spectrometry thin sources were prepared by microprecipitation techniques. Additionally these fractions separated from the soil samples were measured by Accelerator Mass Spectrometry (AMS) to get information on the isotopic ratios 236U/238U, 240Pu/239Pu and 236U/239Pu, respectively. The 236U concentrations [atoms/g] in each surface layer (∼2 cm) were surprisingly high compared to deeper layers where values around two orders of magnitude smaller were found. Since the isotopic ratio 240Pu/239Pu indicated a global fallout signature we assume the same origin as the probable source for 236U. Our measured 236U/239Pu value of around 0.2 is within the expected range for this contamination source. PMID:21481502

  4. Crustal subsidence rate off Hawaii determined from 234U/238U ages of drowned coral reefs

    Science.gov (United States)

    Ludwig, K. R.; Szabo, B. J.; Moore, J.G.; Simmons, K.R.

    1991-01-01

    A series of submerged coral reefs off northwestern Hawaii was formed during (largely glacial) intervals when the rate of local sea-level rise was less than the maximum upward growth rate of the reefs. Mass-spectrometric 234U/238U ages for samples from six such reefs range from 17 to 475 ka and indicate that this part of the Hawaiian Ridge has been subsiding at a roughly uniform rate of 2.6 mm/yr for the past 475 ka. The 234U/238U ages are in general agreement with model ages of reef drowning (based on estimates of paleo-sea-level stands derived from oxygen-isotope ratios of deep-sea sediments), but there are disagreements in detail. The high attainable precision (??10 ka or better on samples younger than ~800 ka), large applicable age range, relative robustness against open-system behavior, and ease of analysis for this technique hold great promise for future applications of dating of 50-1000 ka coral. -Authors

  5. Intermediate structure in the /sup 238/U neutron capture cross section

    Energy Technology Data Exchange (ETDEWEB)

    Perez, R.B.; de Saussure, G.

    1975-10-01

    Recent measurements of the /sup 238/U neutron capture cross section show large fluctuations in the unresolved resonance region. To test whether or not the observed long-range fluctuation of the neutron capture represent departures from the compound nuclear model, the Wald-Wolfowitz runs and correlation tests were applied to the /sup 238/U neutron capture data obtained at ORELA. The Wald-Wolfowitz runs test deals with the statistic, R, which is the number of unbroken sequences of data points above or below a given reference line. This statistic is to be compared with the expected value of runs E(R) +- sigma(R) arising from randomly distributed data. In the correlation test we have computed the first serial correlation coefficient of the data as well as its expected value and variance for a set of random data. In both tests one computes the probability, P, for the given statistical entity to depart from its expected value by more than epsilon standard deviations. Both tests confirm the presence of intermediate structure between 5 and 100 keV. The range of the structure far exceeds the width of the experimental resolution and level widths. 3 tables, 2 figures. (auth)

  6. Analysis of the {sup 238}U resonance parameters using random-matrix theory

    Energy Technology Data Exchange (ETDEWEB)

    Courcelle, A. [CEA Cadarache, 13 - Saint Paul lez Durance (France); Derrien, H.; Leal, L.C.; Larson, N.M. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2005-07-01

    Random-matrix theories (RMTs) provide valuable statistical tools to analyze neutron-resonance data. The predictive power of the random-matrix theories, which do not contain any adjustable parameters, is striking, and the application is rather simple and fast. A new evaluation of {sup 238}U resonance parameters has recently been performed at the Oak Ridge National Laboratory; the objective of this paper is to illustrate the use of RMT in the field of resonance-parameter evaluation with the newly evaluated {sup 239}U energy levels and widths. Several statistics were computed using the s-wave resonances up to 20 keV and compared to the Gaussian Orthogonal Ensemble predictions. It is shown that a good agreement is observed between RMT and the experimental data up to 2.5 keV. The F-Dyson statistic was especially investigated because of its claimed ability to detect locally missed and spurious levels in the sample (p-resonances contamination or unresolved multiplets). As expected, the entire set of evaluated {sup 238}U s-wave resonances up to 20 keV disagrees significantly with the theory. There are two reasons for this: First, it is difficult to distinguish s- and p-wave resonances in the analysis. Secondly, especially above 10 keV, it is impossible to determine reliable resonance energies from the available experimental data. It is concluded that the use of RMT can help nuclear data specialists to improve their evaluations in the resonance range. (authors)

  7. Non- identical thermochemical behavior of 234U-and 238U- isotopes in metamict britholite.

    Science.gov (United States)

    Skriplev, Mikhail I; Bogdanov, Roman V; Schwink, Lawrence R

    2017-01-01

    A radiochemical analysis of the valence state of uranium isotopes in minerals involves isolation of the U(IV) and U(VI) valence forms and determination of the radioactivity of the 234U and 238U isotopes in each fraction. If the nuclear decay of the uranium in the minerals is accompanied by a redox process, the distribution of the 234U isotope in the U(IV) and U(VI) forms will differ from that of the 238U isotope: oxidation leads to enrichment of the U(VI) fraction with the radiogenic 234U isotope; reduction facilitates enrichment of the U(IV) fraction with 234U. If the mineral is heated to 600-700°C before the radiochemical analysis, then an equilibrium activity ratio (AR) for both valences. The question arises: What are the processes that bring this about? The authors of this research studied changes of the AR in the U(IV) and U(VI) fractions after isochronous thermal annealing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. (238)U and total radioactivity in drinking waters in Van province, Turkey.

    Science.gov (United States)

    Selçuk Zorer, Özlem; Dağ, Beşir

    2014-06-01

    As part of the national survey to evaluate natural radioactivity in the environment, concentration levels of total radioactivity and natural uranium have been analysed in drinking water samples. A survey to study natural radioactivity in drinking waters was carried out in the Van province, East Turkey. Twenty-three samples of drinking water were collected in the Van province and analysed for total α, total β and (238)U activity. The total α and total β activities were counted by using the α/β counter of the multi-detector low background system (PIC MPC-9604), and the (238)U concentrations were determined by inductively coupled plasma-mass spectrometry (Thermo Scientific Element 2). The samples were categorised according to origin: tap, spring or mineral supply. The activity concentrations for total α were found to range from 0.002 to 0.030 Bq L(-1) and for total β from 0.023 to 1.351 Bq L(-1). Uranium concentrations ranging from 0.562 to 14.710 μg L(-1) were observed in drinking waters. Following the World Health Organisation rules, all investigated waters can be used as drinking water.

  9. Oceanic stratified euphotic zone as elucidated by /sup 234/Th:/sup 238/U disequilibria

    Energy Technology Data Exchange (ETDEWEB)

    Coale, K.H.; Bruland, K.W.

    1987-01-01

    Profiles of dissolved and particulate /sup 234/Th were determined at the VERTEX 2 and 3 stations off Manzanillo, Mexico, and at the VERTEX 4 station about 900 km north of Hawaii. By modeling the disequilibria between /sup 234/Th and /sup 238/U in the dissolved and particulate form, estimates of scavenging rates for Th from the dissolved to particulate phases, particle residence times, and the flux of Th via particle removal can be obtained. /sup 234/Th:/sup 238/U activity ratio profiles indicate that the euphotic zone can be separated into two layers: an upper oligotrophic layer characterized by low new production values, low net scavenging, and long dissolved /sup 234/Th residence times; and a subsurface eutrophic layer with higher new production values, more intense scavenging, and shorter dissolved /sup 234/Th residence times. New production, rather than total primary production may determine net scavenging rates of reactive elements from oceanic surface waters. These results contribute to the emerging descriptions of the layered structure of oligotrophic euphotic zones and support the notion that this may be a general and ubiquitous feature of global stratified oligotrophic regimes.

  10. Toxicity Reduction of Reactive Red Dye-238 Using Advanced Oxidation Process by Solar Energy

    Directory of Open Access Journals (Sweden)

    Riyad Al-Anbari

    2017-09-01

    Full Text Available Decolorization of red azo dye (Cibacron Red FN-R from synthetic wastewater has been investigated as a function of solar advanced oxidation process. The photocatalytic activity using ZnO as a photocatalysis has been estimated. Different parameters affected the removal efficiency, including pH of the solution, initial dye concentration and H2O2 concentration were evaluated to find out the optimum value of these parameters. The results proved that the optimal pH value was 8 and the most efficient H2O2 concentration was 100mg/L. Toxicity reduction percent for effluent solution was also monitored to assess the degradation process. This treatment method was able to strongly reduce the color and toxicity of reactive red dye-238 to about (99 and 80 % respectively. It can be concluded, from these experiments, that the using of ZnO as a photocatalysis was exhibited as economical and efficient treatment method to remove reactive red dye-238 from aqueous solution.

  11. The tumor necrosis factor-α-238 polymorphism and digestive system cancer risk: a meta-analysis.

    Science.gov (United States)

    Hui, Ming; Yan, Xiaojuan; Jiang, Ying

    2016-08-01

    Many studies have reported the association between tumor necrosis factor-α (TNF-α)-238 polymorphism and digestive system cancer susceptibility, but the results were inconclusive. We performed a meta-analysis to derive a more precise estimation of the relationship between TNF-α-238 G/A polymorphism and digestive system cancer risk. Pooled analysis for the TNF-α-238 G/A polymorphism contained 26 studies with a total of 4849 cases and 8567 controls. The meta-analysis observed a significant association between TNF-α-238 G/A polymorphism and digestive system cancer risk in the overall population (GA vs GG: OR 1.19, 95 % CI 1.00-1.40, P heterpgeneity = 0.016; A vs G: OR 1.19, 95 % CI 1.03-1.39, P heterpgeneity = 0.015; dominant model: OR 1.20, 95 % CI 1.02-1.41, P heterpgeneity = 0.012). In the analysis of the ethnic subgroups, however, similar results were observed only in the Asian population, but not in the Caucasian population. Therefore, this meta-analysis suggests that TNF-α-238 G/A polymorphism is associated with a significantly increased risk of digestive system cancer. Further large and well-designed studies are needed to confirm these findings.

  12. Acceptable knowledge summary report for combustible/noncombustible, metallic, and HEPA filter waste resulting from {sup 238}Pu fabrication activities

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, P.S.Z.; Foxx, C.L.

    1998-02-19

    All transuranic (TRU) waste must be sufficiently characterized and certified before it is shipped to the Waste Isolation Pilot Plant (WIPP). The US Environmental Protection Agency (EPA) allows use of acceptable knowledge (AK) for waste characterization. EPA uses the term AK in its guidance document and defines AK and provides guidelines on how acceptable knowledge should be obtained and documented. This AK package has been prepared in accordance with Acceptable Knowledge Documentation (TWCP-QP-1.1-021,R.2). This report covers acceptable knowledge information for five waste streams generated at TA-55 during operations to fabricate various heat sources using feedstock {sup 238}Pu supplied by the Savannah River Site (SRS). The {sup 238}Pu feedstock itself does not contain quantities of RCRA-regulated constituents above regulatory threshold limits, as known from process knowledge at SRS and as confirmed by chemical analysis. No RCRA-regulated chemicals were used during {sup 238}Pu fabrication activities at TA-55, and all {sup 238}Pu activities were physically separated from other plutonium processing activities. Most of the waste generated from the {sup 238}Pu fabrication activities is thus nonmixed waste, including waste streams TA-55-43, 45, and 47. The exceptions are waste streams TA-55-44, which contains discarded lead-lined rubber gloves used in the gloveboxes that contained the {sup 238}Pu material, and TA-55-46, which may contain pieces of discarded lead. These waste streams have been denoted as mixed because of the presence of the lead-containing material.

  13. 239Pu(n,2n) 238Pu cross section inferred from IDA calculations and GEANIE measurements

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H; Ormand, W E; Dietrich, F S

    2000-09-01

    This report presents the latest {sup 239}Pu(n,2n){sup 238}Pu cross sections inferred from calculations performed with the nuclear reaction-modeling code system, IDA, coupled with experimental measurements of partial {gamma}-ray cross sections for incident neutron energies ranging from 5.68 to 17.18 MeV. It is found that the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section peaks at E{sub inc} {approx} 11.4 MeV with a peak value of approximately 326 mb. At E{sub inc} {approx} 14 MeV, the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section is found to be in good agreement with previous radio-chemical measurements by Lockheed. However, the shape of the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section differs significantly from previous evaluations of ENDL, ENDF/B-V and ENDF/B-VI. In our calculations, direct, preequilibrium, and compound reactions are included. Also considered in the modeling are fission and {gamma}-cascade processes in addition to particle emission. The main components of physics adopted and the parameters used in our calculations are discussed. Good agreement of the inferred {sup 239}Pu(n,2n){sup 238}Pu cross sections derived separately from IDA and GNASH calculations is shown. The two inferences provide an estimate of variations in the deduced {sup 239}Pu(n,2n){sup 238}Pu cross section originating from modeling.

  14. Dose-to-the-population exposure estimates for use of plutonium-238-powered artificial hearts

    Energy Technology Data Exchange (ETDEWEB)

    McKee, R.W.; Clark, L.L.; Cole, B.M.

    1976-09-01

    Estimates of dose to the population from /sup 238/Pu-powered artificial hearts were developed using a calculational model called REPRIEVE. This model develops the projected user population by incorporating assumptions regarding future heart disease death rates, the fraction dying who would be eligible candidates for artificial hearts, population projections, beginning implant rates, death rates after implant due to natural causes, and deaths caused by device failure. The user population was characterized by age, sex, household description, employment status and occupation. Census data on household descriptions and special surveys in selected cities provided the information necessary to describe persons exposed during both household and public activities. These surveys further defined distance and time of contact factors for these persons. Calculations using a dosemetry computer code defined the relationships between distance and dose. The validity of these calculations has been substantiated by experimental measurements.

  15. Environmental aspects of the transuranics: a selected, annotated bibliography. [Pu-238, Pu-239

    Energy Technology Data Exchange (ETDEWEB)

    Ensminger, J.T.; Martin, F.M.; Fore, C.S. (comps.)

    1977-03-01

    This eighth published bibliography of 427 references is compiled from the Nevada Applied Ecology Information Center's Data Base on the Environmental Aspects of the Transuranics. The data base was built to provide information support to the Nevada Applied Ecology Group (NAEG) of ERDA's Nevada Operations Office. The general scope covers environmental aspects of uranium and the transuranic elements, with emphasis on plutonium. This bibliography highlights literature on plutonium 238 and 239 and americium in the critical organs of man and animals. Supporting information on ecology of the Nevada Test Site and reviews and summarizing literature on other radionuclides have been included at the request of the NAEG. The references are arranged by subject category with leading authors appearing alphabetically in each category. Indexes are provided for author(s), geographic location, keyword(s), taxon, title, and publication description.

  16. Two-phonon giant resonances in {sup 136}Xe, {sup 208}Pb, and {sup 238}U

    Energy Technology Data Exchange (ETDEWEB)

    Boretzky, K.; Gruenschloss, A.; Ilievski, S.; Adrich, P.; Aumann, T.; Bertulani, C.A.; Cub, J.; Dostal, W.; Eberlein, B.; Elze, T.W.; Emling, H.; Fallot, M.; Holeczek, J.; Holzmann, R.; Kozhuharov, C.; Kratz, J.V.; Kulessa, R.; Leifels, Y.; Leistenschneider, A.; Lubkiewicz, E.; Mordechai, S.; Ohtsuki, T.; Reiter, P.; Simon, H.; Stelzer, K.; Stroth, J.; Suemmerer, K.; Surowiec, A.; Wajda, E.; Walus, W.

    2003-07-01

    The excitation of the double-phonon giant dipole resonance was observed in heavy projectile nuclei impinging on targets of high nuclear charge with energies of 500-700 MeV/nucleon. New experimental data are presented for {sup 136}Xe and {sup 238}U together with further analysis of earlier data on {sup 208}Pb. Differential cross sections d{sigma}/dE{sup *} and d{sigma}/d{theta} for electromagnetic excitations were deduced. Depending on the isotope, cross sections appear to be enhanced in comparison to those expected from a purely harmonic nuclear dipole response. The cumulative effect of excitations of two-phonon states composed of one dipole and one quadrupole phonon, of predicted anharmoniticies in the double-phonon dipole response, and of damping of the dipole resonance during the collision may account for the discrepancy. In addition, decay properties of two-phonon resonances were studied and compared to that of a statistical decay. (orig.)

  17. Status summary of chemical processing development in plutonium-238 supply program

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Emory D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Benker, Dennis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wham, Robert M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DePaoli, David W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Delmau, Laetitia Helene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sherman, Steven R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-10-01

    This document summarizes the status of development of chemical processing in the Plutonium-238 Supply Program (PSP) near the end of Demonstration 1. The objective of the PSP is “to develop, demonstrate, and document a production process that meets program objectives and to prepare for its operation” (Frazier et al. 2016). Success in the effort includes establishing capability using the current infrastructure to produce Np targets for irradiation in Department of Energy research reactors, chemically processing the irradiated targets to separate and purify the produced Pu and transferring the PuO2 product to Los Alamos National Laboratory (LANL) at an average rate of 1.5 kg/y.

  18. /sup 238/Pu fuel-form processes. Quarterly report, January-March 1982

    Energy Technology Data Exchange (ETDEWEB)

    1982-07-01

    Progress in the Savannah River /sup 238/Pu Fuel Form Program is summarized. Analytical studies of weld quench cracking in DOP-26 iridium alloy-clad vent sets are reported. Cracks that occur in the arc quench region of the girth welds on DOP-26 iridium alloy-clad vent sets (CVS) have been a problem in production of general-purpose heat sources (GPHS) in the Savannah River Plant (SRP) Plutonium Fuel Form (PuFF) Facility. Previous analytical work has shown that alloy grain boundaries in cracks have a characteristic ridge network porosity. Such porosity is thought to weaken the grain boundaries and promote cracking. Efforts are being made to identify the mechanism responsible for producing the ridge network porosity.

  19. Positron spectra from internal pair conversion observed in 238U + 181Ta collisions

    CERN Document Server

    Heinz, S.; Heine, F.; Joeres, O.; Kienle, P.; Konig, I.; Konig, W.; Kozhuharov, C.; Leinberger, U.; Rhein, M.; Schroter, A.; Tsertos, Haralabos

    2000-01-01

    We present new results from measurements and simulations of positron spectra, originating from 238U + 181Ta collisions at beam energies close to the Coulomb barrier. The measurements were performed using an improved experimental setup at the double-Orange spectrometer of GSI. Particular emphasis is put on the signature of positrons from Internal-Pair-Conversion (IPC) processes in the measured e+ energy spectra, following the de-excitation of electromagnetic transitions in the moving Ta-like nucleus. It is shown by Monte Carlo simulations that, for the chosen current sweeping procedure used in the present experiments, positron emission from discrete IPC transitions can lead to rather narrow line structures in the measured energy spectra. The measured positron spectra do not show evidence for line structures within the statistical accuracy achieved, although expected from the intensities of the observed $\\gamma$ transitions (E$_{\\gamma}~1250-1600$ keV) and theoretical conversion coefficients. This is due to the...

  20. An evaluation of alternate production methods for Pu-238 general purpose heat source pellets

    Energy Technology Data Exchange (ETDEWEB)

    Mark Borland; Steve Frank

    2009-06-01

    For the past half century, the National Aeronautics and Space Administration (NASA) has used Radioisotope Thermoelectric Generators (RTG) to power deep space satellites. Fabricating heat sources for RTGs, specifically General Purpose Heat Sources (GPHSs), has remained essentially unchanged since their development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the applicable fields of chemistry, manufacturing and control systems. This paper evaluates alternative processes that could be used to produce Pu 238 fueled heat sources. Specifically, this paper discusses the production of the plutonium-oxide granules, which are the input stream to the ceramic pressing and sintering processes. Alternate chemical processes are compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product.

  1. 238U Neutron Capture Cross Section Measurements at the GELINA Facility

    Science.gov (United States)

    Lampoudis, C.; Kopecky, S.; Becker, B.; Gunsing, F.; Schillebeeckx, P.; Wynants, R.

    2014-05-01

    A set of neutron capture experiments based on the time-of-flight technique were performed in order to determine the 238U capture cross section in the unresolved resonance region. The GELINA facility of the Institute for Reference Materials and Measurements (IRMM) served as the neutron source. A pair of C6D6 liquid scintillators was used to register the prompt gamma rays emerging from the uranium sample. The analysis of the experimental data is based on the total energy principle applied in combination with the pulse height weighting technique. The experimental details along with the analysis process are described. The first results in the resolved resonance region are presented and their validity provide a solid base to extend the analysis and extract the average cross section in the keV region.

  2. Investigation of zircon/zirconia ceramics doped with {sup 239}Pu and {sup 238}Pu

    Energy Technology Data Exchange (ETDEWEB)

    Burakov, B.E.; Anderson, E.B.; Zamoryanskaya, M.V.; Nikolaeva, E.V.; Strykanova, E.E.; Yagovkina, M.A. [V.G. Khlopin Radium Institute, Saint Petersburg (Russian Federation)

    2001-07-01

    Several samples of crystalline double-phase ceramics based on zircon, (Zr,Pu)SiO{sub 4} and zirconia, (Zr,Pu)O{sub 2}, were synthesized by sintering in air, precursors containing approximately 5-6 and 10 wt% {sup 239}Pu, respectively. One sample doped with 5-6 wt% {sup 238-39-40}Pu was also obtained under the same conditions. All ceramic samples were studied by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and MCC-1 leach test in deionized water at 90 C. Results indicate that even radiation damaged zircon/zirconia ceramics retain high chemical resistance and mechanical durability. (author)

  3. Influence of soil structure on the "Fv approach" applied to 238U and 226Ra.

    Science.gov (United States)

    Blanco Rodríguez, P; Vera Tomé, F; Lozano, J C

    2017-02-01

    The soil-to-plant transfer factors were determined in a granitic area for the two long-lived uranium series radionuclides 238U and 226Ra. With the aim to identify a physical fraction of soil whose concentration correlates linearly with the plant concentration, the soil compartment was analyzed in various stages. An initial study identified the soil compartments as being either bulk soil or its labile fraction. The bulk soil was subsequently divided into three granulometric fractions consisting of: coarse sand, fine sand, and silt and clay. The soil-to-plant transfer of radionuclides for each of these three texture fractions was analyzed. Lastly, the labile fraction was extracted from each textural part, and the activity concentration of the radionuclides 238U and 226Ra was measured. In order to assess the influence of soil texture on the soil-to-plant transfer process, we sought to identify possible correlations between the activity concentration in the plant compartment and those found in the different fractions within each soil compartment. The results showed that the soil-to-plant transfer process for uranium and radium depends on soil grain size, where the results for uranium showed a linear relationship between the activity concentration of uranium in the plant and the fine soil fraction. In contrast, a linear relation between the activity concentration of radium in the plant and the soil coarse-sand fraction was observed. Additionally, the presence of phosphate and calcium in the soil of all of the compartments studied affected the soil-to-plant transfer of uranium and radium, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Development of fast measurements of concentration of NORM U-238 by HPGe

    Science.gov (United States)

    Cha, Seokki; Kim, Siu; Kim, Geehyun

    2017-02-01

    Naturally Occureed Radioactive Material (NORM) generated from the origin of earth can be found all around us and even people who are not engaged in the work related to radiation have been exposed to unnecessary radiation. This NORM has a potential risk provided that is concentrated or transformed by artificial activities. Likewise, a development of fast measruement method of NORM is emerging to prevent the radiation exposure of the general public and person engaged in the work related to the type of business related thereto who uses the material in which NORM is concentrated or transfromed. Based on such a background, many of countries have tried to manage NORM and carried out regulatory legislation. To effienctly manage NORM, there is need for developing new measurement to quickly and accurately analyze the nuclide and concentration. In this study, development of the fast and reliable measurement was carried out. In addition to confirming the reliability of the fast measurement, we have obtained results that can suggest the possibility of developing another fast measurement. Therefore, as a follow-up, it is possible to develop another fast analytical measurement afterwards. The results of this study will be very useful for the regulatory system to manage NORM. In this study, a review of two indirect measurement methods of NORM U-238 that has used HPGe on the basis of the equilibrium theory of relationships of mother and daughter nuclide at decay-chain of NORM U-238 has been carried out. For comparative study(in order to know reliabily), direct measurement that makes use of alpha spectrometer with complicated pre-processing process was implemented.

  5. Assessment of uranium exposure from total activity and 234U:238U activity ratios in urine.

    Science.gov (United States)

    Nicholas, T; Bingham, D

    2011-03-01

    Radiation workers at Atomic Weapons Establishment (AWE) are monitored for uranium exposure by routine bioassay sampling (primarily urine sampling). However, the interpretation of uranium in urine and faecal results in terms of occupational intakes is difficult because of the presence of uranium due to intakes from environmental (dietary) sources. For uranium in urine data obtained using current analytical techniques at AWE, the mean, median and standard deviation of excreted uranium concentrations were 0.006, 0.002 and 0.012 μg per g creatinine, respectively. These values are consistent with what might be expected from local dietary intakes and the knowledge that occupational exposures at AWE are likely to be very low. However, some samples do exceed derived investigation levels (DILs), which have been set up taking account of the likely contribution from environmental sources. We investigate how the activity and isotopic composition of uranium in the diet affects the sensitivity of uranium in urine monitoring for occupational exposures. We conclude that DILs based on both total uranium in urine activity and also (234)U:(238)U ratios are useful given the likely variation in dietary contribution for AWE workers. Assuming a background excretion rate and that the enrichment of the likely exposure is known, it is possible to assess exposures using (234)U:(238)U ratios and/or total uranium activity. The health implications of internalised uranium, enriched to 235)U, centre on its nephrotoxicity; the DILs for bioassay samples at AWE are an order of magnitude below the conservative recommendations made by the literature.

  6. 238 U, 232 Th and 40 K in wheat flour samples of Iraq markets

    Directory of Open Access Journals (Sweden)

    Ali Abid Abojassim

    2015-05-01

    Full Text Available Introduction. Wheat flour is a nutritious type of food that is widely consumed by various age groups in Iraq. This study investigates the presence of long-lived gamma emitters in different type of wheat flour in Iraqi market. Materials and methods. Uranium (238 U, Thorium (232 Th and Potassium (40 K specific activity in (Bq/kg were measured in (12 different types of wheat flours that are available in Iraqi markets. The gamma spectrometry method with a NaI(Tl detector has been used for radiometric measurements. Also in this study we have calculated the internal hazard index, radium equivalent and absorbed dose rate in all samples. Results and discussion. It is found that the specific activity in wheat flour samples were varied from (1.086±0.0866 Bq/kg to (12.532±2.026 Bq/kg with an average (6.6025 Bq/kg for 238 U, For 232 Th From (0.126±0.066 Bq/kg to (4.298±0.388 Bq/kg with an average (1.9465Bq/kg and for 40 K from (41.842±5.875 Bq/kg to (264.729±3.843 Bq/kg with an average (133.097 Bq/kg. Also, it is found that the radium equivalent and the internal hazard index in wheat flour samples ranged from (3.4031 Bq/kg to (35.1523 Bq/kg with an average (19.6346 Bq/kg and from (0.0091 to (0.1219 with an average (0.0708 respectively. Conclusion. This study prove that the natural radioactivity and radiation hazard indices were lower than the safe.

  7. ADSORPTION OF Th-232 AND U-238 BY γ- Al2O3-HUMATE AT SINGLE AND COMPETITIVE SYSTEMS

    Directory of Open Access Journals (Sweden)

    Muzakky Muzakky

    2010-06-01

    Full Text Available The calculation experiments of adsorption capacities of Th-232 and U-238 in γ- Al2O3-humate at single system and competitive with Freundlich method has been done. The purpose of the research is (1 to characterize γ- Al2O3-humat functional groups, (2 to know γ- Al2O3-humat solubility and (3 to predict adsorption capacities of U-238 and of Th-232 at adsorbent γ-Al2O3-humate. The characterization of functional groups γ- Al2O3-humate is done by Fourier Transform Infra red (FTIR Spectrometry. Based on perception results of functional spectra characteristic of γ-Al2O3-humate is similar with humic substance with decrease at stretching -OH at 3400 - 3300 cm-1, and C=O stretching of COOH spectra, C=C aromatic or hydrogen bond of C=O at 1725-1720 cm-1spectra. The solubility testing of γ-Al2O3-humate indicated that the compound it's effective used as adsorption U-238 and of Th-232 at pH 1 to 4 conditions. At single adsorption system with 1000 mg/L of U-238 or Th-232 feed, 0.001 g up to 0.1 g weight of γ-Al2O3-humate were got for U-238 balanced to 992.15 mg/L and 980.66 mg/L for Th-232.  By using regression line curve between ln C and ln x/m, adsorption capacities of U-238 and Th-232 at single system can be calculated as 3.63 mg/g and 2.93 mg/g, respectively, while adsorption capacity of Th-232 was increases to 8.08 mg/g and U-238 decreases to 0.91 mg/g at competitive system.   Keywords: U-238, Th-232, adsorption Freundlich, Spectrometry Fourier Transform Infra Red

  8. Neutron Capture Cross Sections and Gamma Emission Spectra from Neutron Capture on 234,236,238U Measured with DANCE

    Science.gov (United States)

    Ullmann, J. L.; Mosby, S.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Jandel, M.; Kawano, T.; O'Donnell, J. M.; Rundberg, R. S.; Vieira, D. J.; Wilhelmy, J. B.; Wu, C.-Y.; Becker, J. A.; Chyzh, A.; Baramsai, B.; Mitchell, G. E.; Krticka, M.

    2014-05-01

    A new measurement of the 238U(n, γ) cross section using a thin 48 mg/cm2 target was made using the DANCE detector at LANSCE over the energy range from 10 eV to 500 keV. The results confirm earlier measurements. Measurements of the gamma-ray emission spectra were also made for 238U(n, γ) as well as 234,236U(n, γ). These measurements help to constrain the radiative strength function used in the cross-section calculations.

  9. Mechanical behavior of {sup 238}UO{sub 2}, {sup 238}PuO{sub 2}, and {sup 239}PuO{sub 2} as a function of strain rate and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Stout, M.G.; Ellis, R.W.; Pereyra, R.A.

    1994-08-01

    The mechanical response of {sup 238}UO{sub 2} was measured as a function of strain rate and temperature. We evaluated material produced by two processing schedules: hot pressing followed by a grain stabilization; and cold pressing plus a sintering treatment. The response of these two materials was identical, within the scatter of our data. We complemented our data with that published in the literature, after having made the appropriate corrections for grain size, porosity, and stoichiometry. The entire collection of data was used to evaluate the Follansbee-Kocks mechanical threshold stress (MTS) model for the prediction of yield stress as a function of strain rate and temperature. We used this model to predict the yield stress of {sup 238}UO{sub 2} for strain rates between {dot {var_epsilon}} = 10{sup {minus}5} and 10{sup 3} s{sup {minus}1} and temperatures from 800 to 1600C. These predictions provided the basis for constructing a deformation/fracture map for both urania and plutonia. Examination of the maps indicates that for compressive loading and impact strain rates, the {sup 238}UO{sub 2} will be an excellent mock material for {sup 238}PuO{sub 2}. Under these conditions both the strength and deformation and the fracture modes are consistent between these two materials.

  10. Deconvolution of 238,239,240Pu conversion electron spectra measured with a silicon drift detector

    DEFF Research Database (Denmark)

    Pommé, S.; Marouli, M.; Paepen, J.

    2017-01-01

    Internal conversion electron (ICE) spectra of thin 238,239,240Pu sources, measured with a windowless Peltier-cooled silicon drift detector (SDD), were deconvoluted and relative ICE intensities were derived from the fitted peak areas. Corrections were made for energy dependence of the full-energy-...

  11. Biokinetics aand dosimetry of inhaled {sup 238}PuO{sub 2} in the beagle dog: An update

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R.A.; Griffith, W.C.; Diel, J.H.

    1994-11-01

    The temporal and spatial distributions of {sup 238}Pu have been measured during the course of a dose-response study of the biological effects of inhaled {sup 238}PuO{sub 2} in Beagle dogs. These measurements were done on the dose-response study animals, as well as a separate group of dogs exposed to similar aerosols and killed serially out to 4 y after exposure. The data from this latter group provided the basis for the development of a biokinetic/dosimetric model for {sup 238}PuO{sub 2} in dogs. Since the publication of this model, several important findings have been made that affected the dosimetric evaluations. The first involved the discovery of significant quantities of natural uranium (U) in the feces samples. The U was measured with the plutonium (Pu), which inflated the values for purported Pu in feces. The second finding involved the addition of Pu biokinetics data from the dose-response dogs, which increased the period of observation from 4 y to 15 y; these later data were not consistent with the earlier model predictions. The purpose of this investigation was (1) to remove the analytical bias in the {sup 238}Pu radiochemical data due to the U and (2) to modify the original model of Mewhinney and Diel, taking into account all data from both studies.

  12. Uranium stable isotope fractionation in the Black Sea: Modern calibration of the 238U/235U paleo-redox proxy

    Science.gov (United States)

    Rolison, John M.; Stirling, Claudine H.; Middag, Rob; Rijkenberg, Micha J. A.

    2017-04-01

    The isotopic compositions of redox-sensitive metals, including uranium (U), in marine sediments have recently emerged as powerful diagnostic tracers of the redox state of the ancient ocean-atmosphere system. Reliable interpretation of sedimentary isotopic information requires a thorough understanding of the environmental controls on isotopic fractionation in modern anoxic environments before being applied to the paleo-record. In this study, the relationship between ocean anoxia and the isotopic fractionation of U was investigated in the water column and sediments of the Black Sea, the world's largest anoxic basin. Paired measurements of 238U/235U and U concentration, supported by other redox parameters, were obtained for water column and sediment samples collected during the 2013 GA04N GEOTRACES expedition to the Black Sea. Removal of U from the water column occurs during the redox transition of soluble U(VI) to relatively insoluble U(IV), resulting in up to 43% of U being removed from solution in euxinic bottom waters. Uranium reduction and removal is accompanied by a progressive shift in 238U/235U towards isotopically light values in the water column as heavier 238U is preferentially exported to sediments over lighter 235U. This gives rise to apparent isotope enrichment factors of ε = -0.63 ± 0.09‰ and ε = -0.84 ± 0.11‰ when U removal is modelled by Rayleigh and closed system equilibrium isotope fractionation, respectively. These ε values fall within the range determined for bacterial U reduction experiments, and together with a striking correlation between the distributions of U and H2S, implicate microbially-mediated U(VI)-U(IV) reduction as the primary mechanism controlling U isotopic shifts in the Black Sea. The 238U/235U of underlying sediments is related to the the 238U/235U of Black Sea bottom waters through the isotope enrichment factor of the U reduction reaction but the relationship between sedimentary and water column 238U/235U is complicated

  13. Erosion behaviour of WC–10Co–4Cr coating on 23-8-N nitronic steel by HVOF thermal spraying

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Avnish, E-mail: avnishmnit@gmail.com [Department of Metallurgical and Materials Engineering, Malaviya National Institute of Technology, Jaipur, Rajasthan 302017 (India); Sharma, Ashok, E-mail: ashok.mnit12@gmail.com [Department of Metallurgical and Materials Engineering, Malaviya National Institute of Technology, Jaipur, Rajasthan 302017 (India); Goel, S.K., E-mail: skgoel@splsteel.com [Star Wire India Ltd., Ballabgarh, Haryana 121404 (India)

    2016-05-01

    Highlights: • WC–10Co–4Cr powder was HVOF sprayed on cast and solution treated 23-8-N nitronic steel. • Coated solution treated 23-8-N steel shows homogeneous microstructure, less decarburization and high fracture toughness as compared to coated cast steel. • Erosion behaviour of both coated steels was evaluated at two different impact angles. • Coated solution treated 23-8-N nitronic steel exhibits higher erosion resistance as compared to coated cast steel. • Key erosion resistance factors: homogeneous and well-bonded structure, high fracture toughness, optimum substrate properties. - Abstract: WC–10Co–4Cr coating was deposited by high-velocity oxy-fuel (HVOF) process on cast and solution treated (1220 °C/150 min) 23-8-N nitronic steel substrates. Solution treated substrate has shown higher toughness, ductility and impact energy with a marginal reduction in hardness as compared to cast substrate. This influence the coating deposition efficiency and erosion behaviour. Erosion resistance of coatings was evaluated by air jet erosion tester on two different impact angles (30° and 90°). Phases, microstructure and eroded surface of the coating were characterised by X-ray diffraction (XRD) analysis and field-emission scanning electron microscopy (FESEM) respectively. It is observed that coating on solution treated substrate was superior to cast substrate. The reason being that coating has dense and well-bonded structure with low porosity, less decarburization and inter-splat oxidation. Higher erosion resistance of coated solution treated 23-8-N nitronic steel was attributed to combination of high fracture toughness and hardness of coating including optimum mechanical properties of the substrate. FESEM analysis reveals that erosion response of WC–10Co–4Cr coating also dependent on the relative size of the impact crater with respect to the WC grain size. Coating is removed by combined mode of ductile and brittle erosion.

  14. Thermal Safety Analyses for the Production of Plutonium-238 at the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, Christopher J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Freels, James D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hobbs, Randy W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jain, Prashant K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Maldonado, G. Ivan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-01

    There has been a considerable effort over the previous few years to demonstrate and optimize the production of plutonium-238 (238Pu) at the High Flux Isotope Reactor (HFIR). This effort has involved resources from multiple divisions and facilities at the Oak Ridge National Laboratory (ORNL) to demonstrate the fabrication, irradiation, and chemical processing of targets containing neptunium-237 (237Np) dioxide (NpO2)/aluminum (Al) cermet pellets. A critical preliminary step to irradiation at the HFIR is to demonstrate the safety of the target under irradiation via documented experiment safety analyses. The steady-state thermal safety analyses of the target are simulated in a finite element model with the COMSOL Multiphysics code that determines, among other crucial parameters, the limiting maximum temperature in the target. Safety analysis efforts for this model discussed in the present report include: (1) initial modeling of single and reduced-length pellet capsules in order to generate an experimental knowledge base that incorporate initial non-linear contact heat transfer and fission gas equations, (2) modeling efforts for prototypical designs of partially loaded and fully loaded targets using limited available knowledge of fabrication and irradiation characteristics, and (3) the most recent and comprehensive modeling effort of a fully coupled thermo-mechanical approach over the entire fully loaded target domain incorporating burn-up dependent irradiation behavior and measured target and pellet properties, hereafter referred to as the production model. These models are used to conservatively determine several important steady-state parameters including target stresses and temperatures, the limiting condition of which is the maximum temperature with respect to the melting point. The single pellet model results provide a basis for the safety of the irradiations, followed by parametric analyses in the initial prototypical designs

  15. 49 CFR Appendix F to Part 238 - Alternative Dynamic Performance Requirements for Front End Structures of Cab Cars and MU Locomotives

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Alternative Dynamic Performance Requirements for... TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Pt. 238, App. F Appendix F to Part 238—Alternative Dynamic... and allow for the application of dynamic performance criteria to cab cars and MU locomotives as an...

  16. 238U(n, γ reaction cross section measurement with C6D6 detectors at the n_TOF CERN facility.

    Directory of Open Access Journals (Sweden)

    Mingrone F.

    2014-03-01

    Full Text Available The radiative capture cross section of 238U is very important for the developing of new reactor technologies and the safety of existing ones. Here the preliminary results of the 238U(n,γ cross section measurement performed at n_TOF with C6D6 scintillation detectors are presented, paying particular attention to data reduction and background subtraction.

  17. Screening of carcinoma metastasis by flow cytometry: A study of 238 cases.

    Science.gov (United States)

    Acosta, Maria; Pereira, José; Arroz, Maria

    2016-05-01

    Malignant epithelial cells may be detected in different specimens, by immunophenotyping using flow cytometry (FCM). CD326 (epithelial-specific antigen, clone Ber-Ep4) was used to identify epithelial cells, CD45 to discriminate between leucocytes (positive for this antigen) and non-hematological cells (negative for this antigen), and CD33 to identify monocytes/macrophages. This combination is particularly useful in effusions to characterize large cells and distinguish between monocyte/macrophages (CD45+ CD33+ CD326-), mesothelial cells (CD45 ± (dim) CD33 - CD326-) and epithelial cells (CD45 - CD33 - CD326 +). We evaluated the efficiency of flow cytometry to detect malignant epithelial cells in 238 fresh samples, including effusions, lymph node biopsies, fine needle aspirates, bone marrow aspirates, cerebrospinal fluid, among others. These are specimens expected to lack epithelial cells. FCM results were then compared to the results of smear and cell block morphology, as well as immunocytochemistry on paraffin wax embedded cell blocks, when available. Final diagnosis was the gold standard and a very good sensitivity (96.7%) and specificity (99.3%) were obtained. We concluded that the detection of CD326 positive cells using FCM is strongly indicative of the presence of carcinoma cells. © 2015 International Clinical Cytometry Society. © 2015 International Clinical Cytometry Society.

  18. Anomalies in the Charge Yields of Fission Fragments from the ^{238}U(n,f) Reaction.

    Science.gov (United States)

    Wilson, J N; Lebois, M; Qi, L; Amador-Celdran, P; Bleuel, D; Briz, J A; Carroll, R; Catford, W; De Witte, H; Doherty, D T; Eloirdi, R; Georgiev, G; Gottardo, A; Goasduff, A; Hadyńska-Klęk, K; Hauschild, K; Hess, H; Ingeberg, V; Konstantinopoulos, T; Ljungvall, J; Lopez-Martens, A; Lorusso, G; Lozeva, R; Lutter, R; Marini, P; Matea, I; Materna, T; Mathieu, L; Oberstedt, A; Oberstedt, S; Panebianco, S; Podolyák, Zs; Porta, A; Regan, P H; Reiter, P; Rezynkina, K; Rose, S J; Sahin, E; Seidlitz, M; Serot, O; Shearman, R; Siebeck, B; Siem, S; Smith, A G; Tveten, G M; Verney, D; Warr, N; Zeiser, F; Zielinska, M

    2017-06-02

    Fast-neutron-induced fission of ^{238}U at an energy just above the fission threshold is studied with a novel technique which involves the coupling of a high-efficiency γ-ray spectrometer (MINIBALL) to an inverse-kinematics neutron source (LICORNE) to extract charge yields of fission fragments via γ-γ coincidence spectroscopy. Experimental data and fission models are compared and found to be in reasonable agreement for many nuclei; however, significant discrepancies of up to 600% are observed, particularly for isotopes of Sn and Mo. This indicates that these models significantly overestimate the standard 1 fission mode and suggests that spherical shell effects in the nascent fission fragments are less important for low-energy fast-neutron-induced fission than for thermal neutron-induced fission. This has consequences for understanding and modeling the fission process, for experimental nuclear structure studies of the most neutron-rich nuclei, for future energy applications (e.g., Generation IV reactors which use fast-neutron spectra), and for the reactor antineutrino anomaly.

  19. Population of high-spin isomeric states following fragmentation of 238U

    Science.gov (United States)

    Bowry, M.; Podolyák, Zs.; Pietri, S.; Kurcewicz, J.; Bunce, M.; Regan, P. H.; Farinon, F.; Geissel, H.; Nociforo, C.; Prochazka, A.; Weick, H.; Al-Dahan, N.; Alkhomashi, N.; Allegro, P. R. P.; Benlliure, J.; Benzoni, G.; Boutachkov, P.; Bruce, A. M.; Denis Bacelar, A. M.; Farrelly, G. F.; Gerl, J.; Górska, M.; Gottardo, A.; Grębosz, J.; Gregor, N.; Janik, R.; Knöbel, R.; Kojouharov, I.; Kubo, T.; Kurz, N.; Litvinov, Yu. A.; Merchan, E.; Mukha, I.; Naqvi, F.; Pfeiffer, B.; Pfützner, M.; Plaß, W.; Pomorski, M.; Riese, B.; Ricciardi, M. V.; Schmidt, K.-H.; Schaffner, H.; Scheidenberger, C.; Simpson, E. C.; Sitar, B.; Spiller, P.; Stadlmann, J.; Strmen, P.; Sun, B.; Tanihata, I.; Terashima, S.; Valiente Dobón, J. J.; Winfield, J. S.; Wollersheim, H.-J.; Woods, P. J.

    2013-08-01

    Isomeric ratios have been determined for 23 metastable states identified in A≈200 nuclei from Pt to Rn near the valley of stability following fragmentation of 238U. This includes high-spin states with angular momenta ranging from (39/2)ℏ to 25ℏ. The experimental results are discussed together with those of similar experiments performed in this mass region. Isomeric ratios are compared with theoretical predictions where the angular momentum of the fragment arises purely due to the angular momentum of nucleons removed from the projectile. The theoretical yield of low-spin states is generally overestimated. In these cases the assumption of 100% feeding of the isomer may require modification. However, the yield of high-spin isomeric states [Im ≥ (39/2)ℏ] is significantly underestimated and highlights the requirement for a more complete theoretical framework in relation to the generation of fragment angular momentum. The enhanced population of high-spin states reported here is advantageous to future studies involving isomeric beams at fragmentation facilities such as the Rikagaku Kenkyusho RI Beam Factory (Japan) and next-generation facilities at the Facility for Antiproton and Ion Research (Germany) and Facility for Rare Isotope Beams (USA).

  20. Neutron Productions from thin Be target irradiated by 50 MeV/u 238U beam

    Directory of Open Access Journals (Sweden)

    Lee Hee-Seock

    2017-01-01

    Full Text Available Neutrons generated from thin beryllium target by 50 MeV/u 238U beam were measured using activation analysis at 15, 30, 45, and 90 degrees from the beam direction. A 0.085 mm-thick Be stripper of RIBF was used as the neutron generating target. Activation detectors of bismuth, cobalt, and aluminum were placed out of the stripper chamber. The threshold reactions of 209Bi(n, xn210-xBi(x=4~8, 59Co(n, xn60-xCO(x=2~5, 59Co(n, 2nα54Mn, 27Al(n, α24Na, and 27Al(n,2nα22Na were applied to measure the production rates of radionuclides. The neutron spectra were obtained using an unfolding method with the SAND-II code. All of production rates and neutron spectra were compared with the calculated results using Monte Carlo codes, the PHITS and the FLUKA. The FLUKA results showed better agreement with the measurements than the PHITS. The discrepancy between the measurements and the calculations were discussed.

  1. First experimental prompt γ-ray spectra in fast neutron-induced fission of 238U

    Directory of Open Access Journals (Sweden)

    Laborie J.-M.

    2017-01-01

    Full Text Available The knowledge of prompt fission γ-ray emission has been of major interest in reactor physics since few years, but it is also important in the understanding of the fission process. We present here measurements of prompt γ-ray spectra emitted in the fission of 238U. A simple experimental method was used to measure the prompt fission gamma-ray spectrum up to 10 MeV. In this approach, the gamma-rays are measured with a bismuth germanate (BGO detector which offers two significant advantages with respect to other gamma-ray detectors: a high peak-to-total ratio and a high efficiency. The prompt fission neutrons are rejected by the time-of-flight technique between the BGO detector and a fission trigger given by a fission chamber. Prompt fission gamma-ray spectra were measured for 1.7, 5.2 and 15.6 MeV incoming neutron energies at the CEA, DAM, DIF Van de Graaff accelerator.

  2. DIAGNOSING THE BURST INFLUENCE ON ACCRETION IN THE CLOCKED BURSTER GS 1826-238

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Long; Zhang, Shu; Chen, YuPeng; Zhang, Shuang-Nan; Chang, Zhi [Laboratory for Particle Astrophysics, Institute of High Energy Physics, Beijing 100049 (China); Torres, Diego F. [Institució Catalana de Recerca i Estudis Avançats (ICREA), E-08010 Barcelona (Spain); Kretschmar, Peter; Kuulkers, Erik [European Space Astronomy Centre (ESA/ESAC), Science Operations Department, Villanueva de la Cañada (Madrid) (Spain); Li, Jian [Institute of Space Sciences (CSIC–IEEC), Campus UAB, Carrer de Can Magrans, s/n E-08193, Barcelona (Spain)

    2015-06-10

    Type I X-ray bursts on the surface of a neutron star are a unique probe into accretion in X-ray binary systems. However, we know little about the feedback of the burst emission on accretion. Hard X-ray shortages and enhancements of the persistent emission at soft X-rays have been observed. To put these findings in context with the aim of understanding the possible mechanism underneath, we investigated 68 bursts seen by the Rossi X-ray Timing Explorer from the clocked burster GS 1826-238. We diagnosed jointly the burst influence of both soft and hard X-rays, and we found that the observations can be described by the CompTT model with variable normalization, electron temperature, and optical depth. Putting these results in a scenario of coronal Compton cooling via the burst emission would lead to a shortage of cooling power, which may suggest that additional considerations, like the influence of the burst on corona formation, should be accounted for as well.

  3. Angular distribution of fragments from neutron-induced fission of {sup 238}U in the intermediate energy region

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Magnus

    2004-06-01

    Areas ranging from nuclear structure models to accelerator-driven systems benefit from improved neutron-induced fission data in the intermediate energy region. In this Master's degree thesis, the fragment angular distribution from fission of {sup 238}U, induced by 21-MeV neutrons, has been analysed from an experiment performed with the Medley/DIFFICILE setup at the The Svedberg Laboratory in Uppsala. The data have been corrected for low energy neutrons in the beam. The results agree with other experiments, as well as with model calculations. The data should be a starting point for further analysis with a goal to deduce the fission cross-section of {sup 238}U.

  4. High precision measurement of the radiative capture cross section of 238U at the n_TOF CERN facility

    Directory of Open Access Journals (Sweden)

    Mingrone F.

    2017-01-01

    Full Text Available The importance of improving the accuracy on the capture cross-section of 238U has been addressed by the Nuclear Energy Agency, since its uncertainty significantly affects the uncertainties of key design parameters for both fast and thermal nuclear reactors. Within the 7th framework programme ANDES of the European Commission three different measurements have been carried out with the aim of providing the 238U(n,γ cross-section with an accuracy which varies from 1 to 5%, depending on the energy range. Hereby the final results of the measurement performed at the n_TOF CERN facility in a wide energy range from 1 eV to 700 keV will be presented.

  5. Evaluation of Aqueous and Powder Processing Techniques for Production of Pu-238-Fueled General Purpose Heat Sources

    Energy Technology Data Exchange (ETDEWEB)

    2008-06-01

    This report evaluates alternative processes that could be used to produce Pu-238 fueled General Purpose Heat Sources (GPHS) for radioisotope thermoelectric generators (RTG). Fabricating GPHSs with the current process has remained essentially unchanged since its development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the fields of chemistry, manufacturing, ceramics, and control systems. At the Department of Energy’s request, alternate manufacturing methods were compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product. An expert committee performed the evaluation with input from four national laboratories experienced in Pu-238 handling.

  6. Revisiting the U-238 thermal capture cross section and gamma-raymission probabilities from Np-239 decay

    Energy Technology Data Exchange (ETDEWEB)

    Trkov, A.; Molnar, G.L.; Revay, Zs.; Mughabghab, S.F.; Firestone,R.B.; Pronyaev, V.G.; Nichols, A.L.; Moxon, M.C.

    2005-03-03

    The precise value of the thermal capture cross section of238U is uncertain, and evaluated cross sections from various sourcesdiffer by more than their assigned uncertainties. A number of theoriginal publications have been reviewed to assess the discrepant data,corrections were made for more recent standard cross sections andotherconstants, and one new measurement was analyzed. Due to the strongcorrelations in activation measurements, the gamma-ray emissionprobabilities from the beta decay of 239Np were also analyzed. As aresult of the analysis, a value of 2.683 +- 0.012 barns was derived forthe thermal capture cross section of 238U. A new evaluation of thegamma-ray emission probabilities from 239Np decay was alsoundertaken.

  7. High precision measurement of the radiative capture cross section of 238U at the n_TOF CERN facility

    Science.gov (United States)

    Mingrone, F.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Bécares, V.; Barbagallo, M.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M. A.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Durán, I.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Furman, V.; Göbel, K.; Gómez-Hornillos, M. B.; Ganesan, S.; García, A. R.; Giubrone, G.; Gonçalves, I. F.; González, E.; Goverdovski, A.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Heftrich, T.; Hernández-Prieto, A.; Heyse, J.; Jenkins, D. G.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Katabuchi, T.; Ketlerov, V.; Khryachkov, V.; Kivel, N.; Koehler, P.; Kokkoris, M.; Kroll, J.; Krtička, M.; Lampoudis, C.; Langer, C.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Leong, L. S.; Lerendegui-Marco, J.; Losito, R.; Mallick, A.; Manousos, A.; Marganiec, J.; Martínez, T.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mirea, M.; Mondelaers, W.; Paradela, C.; Pavlik, A.; Perkowski, J.; Plompen, A. J. M.; Praena, J.; Quesada, J. M.; Rauscher, T.; Reifarth, R.; Riego-Perez, A.; Robles, M.; Rubbia, C.; Ryan, J. A.; Sabaté-Gilarte, M.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Sedyshev, P.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vermeulen, M. J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiss, C.; Wright, T.; Žugec, P.

    2017-09-01

    The importance of improving the accuracy on the capture cross-section of 238U has been addressed by the Nuclear Energy Agency, since its uncertainty significantly affects the uncertainties of key design parameters for both fast and thermal nuclear reactors. Within the 7th framework programme ANDES of the European Commission three different measurements have been carried out with the aim of providing the 238U(n,γ) cross-section with an accuracy which varies from 1 to 5%, depending on the energy range. Hereby the final results of the measurement performed at the n_TOF CERN facility in a wide energy range from 1 eV to 700 keV will be presented.

  8. Light nuclides produced in the proton-induced spallation of {sup 238}U at 1 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Ricciardi, M.V.; Armbruster, P. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Benlliure, J. [Universidad de Santiago de Compostela (ES)] [and others

    2005-09-01

    The production of light and intermediate-mass nuclides formed in the reaction {sup 1}H+{sup 238}U at 1 GeV was measured at the fragment separator (FRS) at GSI, Darmstadt. The experiment was performed in inverse kinematics, shooting a 1 A GeV {sup 238}U beam on a thin liquid-hydrogen target. 254 isotopes of all elements in the range 7{<=}Z{<=}37 were unambiguously identified, and the velocity distributions of the produced nuclides were determined with high precision. The results show that the nuclides are produced in a very asymmetric binary decay of heavy nuclei originating from the spallation of uranium. All the features of the produced nuclides merge with the characteristics of the fission products as their mass increases. (orig.)

  9. 232Th, 238U, 40K, 137Cs radioactivity concentrations and 137Cs dose rate in Turkish market tea

    Science.gov (United States)

    Kiliç, Önder; Belivermiş, Murat; Topcuoǧlu, Sayhan; Çotuk, Yavuz

    In this study, the activity concentrations of 232Th, 238U, 40K and 137Cs were measured in 10 branded tea samples from local Turkish markets using gamma spectrometry with an HPGe detector. The mean activity concentrations of 232Th, 238U, 40K and 137Cs were found to be 2.7 ± 1.0, 0.9 ± 0.4, 501 ± 42 and 45.04 ± 2.6 Bq kg-1, respectively. The average annual effective 137Cs dose as a consequence of tea consumption was found to be 385 nSv for an adult person, which is not hazardous to public health. The correlation coefficient between 137Cs and 40K was found to be-0.82 in these samples. The present data were compared with those found in other studies.

  10. Field analyses of (238)U and (226)Ra in two uranium mill tailings piles from Niger using portable HPGe detector.

    Science.gov (United States)

    Déjeant, Adrien; Bourva, Ludovic; Sia, Radia; Galoisy, Laurence; Calas, Georges; Phrommavanh, Vannapha; Descostes, Michael

    2014-11-01

    The radioactivities of (238)U and (226)Ra in mill tailings from the U mines of COMINAK and SOMAÏR in Niger were measured and quantified using a portable High-Purity Germanium (HPGe) detector. The (238)U and (226)Ra activities were measured under field conditions on drilling cores with 600s measurements and without any sample preparation. Field results were compared with those obtained by Inductive Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and emanometry techniques. This comparison indicates that gamma-ray absorption by such geological samples does not cause significant deviations. This work shows the feasibility of using portable HPGe detector in the field as a preliminary method to observe variations of radionuclides concentration with the aim of identifying samples of interest. The HPGe is particularly useful for samples with strong secular disequilibrium such as mill tailings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Savannah River Plant 200 Area technical manual. Part SP. Processing of Np/sup 237/ and Pu/sup 238/

    Energy Technology Data Exchange (ETDEWEB)

    Hill, A.J. (comp.)

    1963-01-03

    This manual covers the technology involved in the 200 Area process for the recovery of Np/sup 237/ from certain aqueous waste streams in the separations plants, for the recovery of NP/sup 237/ and Pu/sup 238/ from irradiated NpO/sub 2/-Al slugs and for the fabrication of NpO/sub 2/-Al slugs. The manual contains sections on the fundamental chemistry, the primary recovery of Np by ion exchange, the decontamination of Np by ion exchange, the processing of NpO/sub 2/-Al targets, the separation and purification of Np/sup 237/ and Pu/sup 238/, the finishing of Np, the preparation of NpO/sub 2/, the disposal of spent resin, and the safety aspects of the handling of hydrazine. The section on the fabrication of NpO/sub 2/-Al slugs will be added later. 76 refs., 22 figs.

  12. Solubility of {sup 238}U radionuclide from various types of soil in synthetic gastrointestinal fluids using “US in vitro” digestion method

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok, E-mail: khoo@ukm.edu.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2015-04-29

    238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by “US P in vitro” digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 – 0.209 ppm) than gastrointestinal fluids (0.024 – 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

  13. Concentrations of {sup 238}U and {sup 232}Th in foodstuffs and radiation dose to a rural Moroccan population

    Energy Technology Data Exchange (ETDEWEB)

    Misdaq, M.A. [Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, BP 2390, University Cadi Ayyad, Marrakech (Morocco)], E-mail: misdaq@ucam.ac.ma; Elamyn, H. [Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, BP 2390, University Cadi Ayyad, Marrakech (Morocco); Merzouki, A. [Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, BP 2390, University Cadi Ayyad, Marrakech (Morocco); Remote Sensing and Geomatics of the Environment Laboratory, Ottawa-Carleton Geoscience Centre, Marion Hall, 140 Louis Pasteur, Ottawa, ON, KIN6N5 (Canada)

    2007-10-15

    Uranium ({sup 238}U) and thorium ({sup 232}Th) contents were measured in different foods widely consumed by the rural Moroccan population by using two different types of solid state nuclear track detectors (SSNTDs). The method utilized is based on determining the probabilities for {alpha}-particles emitted by the uranium and thorium series inside the studied materials to reach and be registered on the CR-39 and LR-115 type II SSNTDs and counting the resulting track densities. Total daily intakes of {sup 238}U and {sup 232}Th for a typical food basket were estimated to be 1.27 Bq d{sup -1} and 0.95 Bq d{sup -1}, 1.55 Bq d{sup -1} and 1.18 Bq d{sup -1} and 2.01 Bq d{sup -1} and 1.52 Bq d{sup -1} for the 7-12 y, 12-17 y and adults age groups, respectively. Annual committed equivalent doses were evaluated in the human body compartments of members of the Moroccan rural population due to {sup 238}U and {sup 232}Th from the ingestion of the studied food materials by using the ICRP ingestion dose coefficients. Annual committed effective dose due to {sup 238}U and {sup 232}Th intakes were found to be 3.16 x 10{sup -5} Sv and 10.10 x 10{sup -5} Sv, 3.81 x 10{sup -5} Sv and 10.80 x 10{sup -5} Sv and 3.32 x 10{sup -5} Sv and 12.80 x 10{sup -5} Sv for the 7-12 y, 12-17 y and adults age groups, respectively.

  14. Fission Fragment Angular Distribution measurements of 235U and 238U at CERN n_TOF facility

    Directory of Open Access Journals (Sweden)

    Leal-Cidoncha E.

    2016-01-01

    In order to measure the FFAD of neutron-induced reactions, a fission detection setup based on parallel-plate avalanche counters (PPACs has been developed and successfully used at the CERN-n_TOF facility. In this work, we present the preliminary results on the analysis of new 235U(n,f and 238U(n,f data in the extended energy range up to 200 MeV compared to the existing experimental data.

  15. IUPAC-IUGS status report on the half-lives of 238U, 235U and 234U

    Science.gov (United States)

    Villa, I. M.; Bonardi, M. L.; De Bièvre, P.; Holden, N. E.; Renne, P. R.

    2016-01-01

    The current state of knowledge on the half-lives of the long-lived U radionuclides has been reviewed by the IUPAC-IUGS joint Task Group ;Isotopes in Geosciences;. 238U is assigned a half-life of (4.4683 ± 0.0096) Ga, i.e. a decay constant λ238 = (0.155125 ± 0.000333) Ga-1. The coverage factor is k = 2 for this and all other estimates presented here. The 238U half-life can be used as a reference for the half-lives/decay constants of all other isotopic geochronometers. A revision of the half-life of 235U based on intercomparison of natural geological samples is premature. The improved repeatability of mass spectrometric measurements has revealed Type B uncertainties that had been dismissed as subordinate in the past. The combined uncertainty of these as yet incompletely charted and quantified sources of Type B uncertainty may be no smaller than the currently accepted uncertainty of the α counting experiments. A provisional value for the 234U half-life can be calculated with the assumption of secular equilibrium in the analyzed natural samples. This assumption has not yet been verified independently and its metrological traceability appears sub-optimum. A Type B evaluation suggests that the ca. 0.17% offset between the N(234U)/N(238U) number-ratios of the natural samples used to estimate the 235U half-life and those of the four samples used to estimate the 234U half-life should be compounded into the standard measurement uncertainty of the latter. The resulting provisional uncertainty interval (k = 2) for the 234U half-life is (244.55-247.77) ka, corresponding to λ234 = (2.8203-2.8344) Ma-1.

  16. Investigation of fission properties and evaporation residue measurement in the reactions using 238U target nucleus

    Directory of Open Access Journals (Sweden)

    Saro S.

    2011-10-01

    Full Text Available Fragment mass distributions for fission after full momentum transfer were measured in the reactions of 30Si,34,36 S,31P,40Ar + 238U at bombarding energies around the Coulomb barrier. Mass distributions change significantly as a function of incident beam energy. The asymmetric fission probability increases at sub-barrier energy. The phenomenon is interpreted as an enhanced quasifission probability owing to orientation effects on fusion and/or quasifission. The evaporation residue (ER cross sections were measured in the reactions of 30Si + 238U and 34S + 238U to obtain information on fusion. In the latter reaction, significant suppression of fusion was implied. This suggests that fission events different from compound nucleus are included in the masssymmetric fragments. The results are supported by a model calculation based on a dynamical calculation using Langevin equation, in which the mass distribution for fusion-fission and quasifission fragments are separately determined.

  17. Split-face study of topical 23.8% L-ascorbic acid serum in treating photo-aged skin.

    Science.gov (United States)

    Xu, Tian-Hua; Chen, John Z S; Li, Yuan-Hong; Wu, Yan; Luo, Yao-Jia; Gao, Xing-Hua; Chen, Hong-Duo

    2012-01-01

    L-ascorbic acid has been widely used to treat photo-aged skin. However, its aqueous formula is prone to oxidation. Therefore, a new formula that contains 23.8% L-ascorbic acid and a chemical penetration enhancer was developed. Observe the efficacy and safety of topical 23.8% L-ascorbic acid serum on photo-aged skin. Twenty Chinese women with photo-aged skin were enrolled in this split-face study. They were treated with topical L-ascorbic acid serum with iontophoresis on one side of the face once a day for 2 weeks; the other side of the face was spared treatment through participants' self-control. Changes in photo-aged skin were evaluated using a global evaluation, an overall self-assessment, a spectrophotometer, the phase-shift rapid in vivo measurement of skin (PRIMOS) 3D, and a corneometer. Sixteen of 20 patients (80%) experienced a score decrease of 2 or 3 grades, according to the dermatologist. Fifteen patients (75%) rated their overall satisfaction as excellent or good. Dyspigmentation, surface roughness, and fine lines on the treated side improved significantly. Topical 23.8% L-ascorbic acid serum is effective for the treatment of photo-aged skin and does not cause any obvious side effects.

  18. Radioactivity of Natural Nuclides (40K, 238U, 232Th, 226Ra in Coals from Eastern Yunnan, China

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2015-09-01

    Full Text Available The naturally occurring primordial radionuclides in coals might exhibit high radioactivity, and can be exported to the surrounding environment during coal combustion. In this study, nine coal samples were collected from eastern Yunnan coal deposits, China, aiming at characterizing the overall radioactivity of some typical nuclides (i.e., 40K, 238U, 232Th, 226Ra and assessing their ecological impact. The mean activity concentrations of 238U, 232Th, 40K and 226Ra are 63.86 (17.70–92.30 Bq· kg-1, 23.76 (11.10–37.10 Bq· kg-1, 96.84 (30.60–229.30 Bq· kg-1 and 28.09 Bq·kg-1 (3.10–61.80 Bq·kg-1, respectively. Both 238U and 232Th have high correlations with ash yield of coals, suggesting their inorganic origins. The overall environmental effect of natural radionuclides in studied coals is considered to be negligible, as assessed by related indexes (i.e., radium equivalent activity, air-adsorbed dose rate, annual effective dose, and external hazard index. However, the absorbed dose rates values are higher than the average value of global primordial radiation and the Chinese natural gamma radiation dose rate.

  19. The fate of PrP GPI-anchor signal peptide is modulated by P238S pathogenic mutation.

    Science.gov (United States)

    Guizzunti, Gianni; Zurzolo, Chiara

    2014-01-01

    Glycosylphosphatidylinositol (GPI)-anchored proteins are localized to the plasma membrane via a C-terminally linked GPI anchor. The GPI anchor is added concomitantly to the cleavage of the carboxy-terminal GPI-anchor signal sequence, thereby causing the release of a C-terminal hydrophobic peptide, whose fate has not yet been investigated. Here we followed the fate of the GPI-attachment signal of the prion protein (PrP), a protein implicated in various types of transmissible neurodegenerative spongiform encephalopathies (TSE). The PrP GPI-anchor signal sequence shows a remarkable and unusual degree of conservation across the species and contains two point mutations (M232R/T and P238S) that are responsible for genetic forms of prion disorders. We show that the PrP GPI-anchor signal peptide (SP), but not the one from an unrelated GPI-anchored protein (folate receptor), undergoes degradation via the proteasome. Moreover, the P238S point mutation partially protects the PrP GPI-anchor SP from degradation. Our data provide the first attempt to address the fate of a GPI-anchor SP and identify a role for the P238S mutation, suggesting the possibility that the PrP GPI-anchor SP could play a role in neurodegenerative prion diseases. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Depth profiling of residual activity of ^{237}U fragments as a range verification technique for ^{238}U primary ion beam

    Directory of Open Access Journals (Sweden)

    I. Strašík

    2012-07-01

    Full Text Available Experimental and simulation data concerning fragmentation of ^{238}U ion beam in aluminum, copper, and stainless-steel targets with the initial energy 500 and 950  MeV/u are collected in the paper. A range-verification technique based on depth profiling of residual activity is presented. The irradiated targets were constructed in the stacked-foil geometry and analyzed using gamma-ray spectroscopy. One of the purposes of these experiments was depth profiling of residual activity of induced nuclides and projectile fragments. Among the projectile fragments, special attention is paid to the ^{237}U isotope that has a range very close to the range of the primary ^{238}U ions. Therefore, the depth profiling of the ^{237}U isotope can be utilized for experimental verification of the ^{238}U primary-beam range, which is demonstrated and discussed in the paper. The experimental data are compared with computer simulations by FLUKA, SRIM, and ATIMA, as well as with complementary experiments.

  1. Depth profiling of residual activity of U237 fragments as a range verification technique for U238 primary ion beam

    Science.gov (United States)

    Strašík, I.; Chetvertkova, V.; Mustafin, E.; Pavlovič, M.; Belousov, A.

    2012-07-01

    Experimental and simulation data concerning fragmentation of U238 ion beam in aluminum, copper, and stainless-steel targets with the initial energy 500 and 950MeV/u are collected in the paper. A range-verification technique based on depth profiling of residual activity is presented. The irradiated targets were constructed in the stacked-foil geometry and analyzed using gamma-ray spectroscopy. One of the purposes of these experiments was depth profiling of residual activity of induced nuclides and projectile fragments. Among the projectile fragments, special attention is paid to the U237 isotope that has a range very close to the range of the primary U238 ions. Therefore, the depth profiling of the U237 isotope can be utilized for experimental verification of the U238 primary-beam range, which is demonstrated and discussed in the paper. The experimental data are compared with computer simulations by FLUKA, SRIM, and ATIMA, as well as with complementary experiments.

  2. 234U/238U evidence for local recharge and patterns of groundwater flow in the vicinity of Yucca Mountain, Nevada, USA

    Science.gov (United States)

    Paces, J.B.; Ludwig, K. R.; Peterman, Z.E.; Neymark, L.A.

    2002-01-01

    Uranium concentrations and 234U/238U ratios in saturated-zone and perched ground water were used to investigate hydrologic flow and downgradient dilution and dispersion in the vicinity of Yucca Mountain, a potential high-level radioactive waste disposal site. The U data were obtained by thermal ionization mass spectrometry on more than 280 samples from the Death Valley regional flow system. Large variations in both U concentrations (commonly 0.6-10 ??g 1-1) and 234U/238U activity ratios (commonly 1.5-6) are present on both local and regional scales; however, ground water with 234U/238U activity ratios from 7 up to 8.06 is restricted largely to samples from Yucca Mountain. Data from ground water in the Tertiary volcanic and Quaternary alluvial aquifers at and adjacent to Yucca Mountain plot in 3 distinct fields of reciprocal U concentration versus 234U/238U activity ratio correlated to different geographic areas. Ground water to the west of Yucca Mountain has large U concentrations and moderate 234U/238U whereas ground water to the east in the Fortymile flow system has similar 234U/238U, but distinctly smaller U concentrations. Ground water beneath the central part of Yucca Mountain has intermediate U concentrations but distinctive 234U/238U activity ratios of about 7-8. Perched water from the lower part of the unsaturated zone at Yucca Mountain has similarly large values of 234U/238U. These U data imply that the Tertiary volcanic aquifer beneath the central part of Yucca Mountain is isolated from north-south regional flow. The similarity of 234U/238U in both saturated- and unsaturated-zone ground water at Yucca Mountain further indicates that saturated-zone ground water beneath Yucca Mountain is dominated by local recharge rather than regional flow. The distinctive 234U/238U signatures also provide a natural tracer of downgradient flow. Elevated 234U/238U in ground water from two water-supply wells east of Yucca Mountain are interpreted as the result of induced

  3. Uranium ({sup 238}U)-induced ROS and cell cycle perturbations, antioxidant responses and erythrocyte nuclear abnormalities in the freshwater iridescent shark fish Pangasius sutchi

    Energy Technology Data Exchange (ETDEWEB)

    Annamalai, Sathesh Kumar; Arunachalam, Kantha Deivi, E-mail: kanthad.arunachalam@gmail.com

    2017-05-15

    Highlights: • Exposure to {sup 238}U deteriorated the antioxidant defenses like SOD, CAT and LPO. • Flow cytometric analysis revealed the increase in G2/M phase and S phase. • Micronucleus frequencies increased with Increased {sup 238}U exposure and time. • Exposure to waterborne {sup 238}U induces both chemical and radiotoxicity in P. sutchi. • ROS-mediated {sup 238}U toxic mechanism and the antioxidant responses has been proposed. - Abstract: The strategic plan of this study is to analyze any possible radiological impact on aquatic organisms from forthcoming uranium mining facilities around the Nagarjuna Sagar Dam in the future. The predominantly consumed and dominant fish species Pangasius sutchi, which is available year-round at Nagarjuna Sagar Dam, was selected for the study. To comprehend the outcome and to understand the mode of action of {sup 238}U, the fish species Pangasius sutchi was exposed to ¼ and ½ of the LC{sub 50} doses of waterborne {sup 238}U in a static system in duplicate for 21 days. Blood and organs, including the gills, liver, brain and muscles, were collected at different time periods—0 h, 24 h, 48 h, 72 h, 96 h, 7, days 14 days and 21 days—using ICP-MS to determine the toxic effects of uranium and the accumulation of {sup 238}U concentrations. The bioaccumulation of {sup 238}U in P. sutchi tissues was dependent on exposure time and concentration. The accumulation of uranium was, in order of magnitude, measured as gills > liver > brain > tissue, with the highest accumulation in the gills. It was observed that exposure to {sup 238}U significantly reduced antioxidant enzymes such as superoxide dismutase, catalase, and lipid peroxidase. The analysis of DNA fragmentation by comet assay and cell viability by flow cytometry was performed at different time intervals. DNA histograms by flow cytometry analysis revealed an increase in the G2/M phase and the S phase. The long-term {sup 238}U exposure studies in fish showed increasing

  4. Using 238U/235U ratios to understand the formation and oxidation of reduced uranium solids in naturally reduced zones

    Science.gov (United States)

    Jemison, N.; Johnson, T. M.; Druhan, J. L.; Davis, J. A.

    2016-12-01

    Uranium occurs in groundwater primarily as soluble and mobile U(VI), which can be reduced to immobile U(IV), often observed in sediments as uraninite. Numerous U(VI)-contaminated sites, such as the DOE field site in Rifle, CO, contain naturally reduced zones (NRZ's) that have relatively high concentrations of organic matter. Reduction of heavy metals occurs within NRZ's, producing elevated concentrations of iron sulfides and U(IV). Slow, natural oxidation of U(IV) from NRZ's may prolong U(VI) contamination of groundwater. The reduction of U(VI) produces U(IV) with a higher 238U/235U ratio. Samples from two NRZ sediment cores recovered from the Rifle site revealed that the outer fringes of the NRZ contain U(IV) with a high 238U/235U ratio, while lower values are observed in the center . We suggest that as aqueous U(VI) was reduced in the NRZ, it was driven to lower 238U/235U values, such that U(IV) formed in the core of the NRZ reflects a lower 238U/235U. Two oxidation experiments were conducted by injecting groundwater containing between 14.9 and 21.2 mg/L dissolved O2 as an oxidant into the NRZ. The oxidation of U(IV) from this NRZ increased aqueous U(VI) concentrations and caused a shift to higher 238U/235U in groundwater as U(IV) was oxidized primarily on the outer fringes of the NRZ. In total these observations suggest that the stability of solid phase uranium is governed by coupled reaction and transport processes. To better understand various reactive transport scenarios we developed a model for the formation and oxidation of NRZ's utilizing the reactive transport software CrunchTope. These simulations suggest that the development of isotopically heterogeneous U(IV) within NRZ's is largely controlled by permeability of the NRZ and the U(VI) reduction rate. Oxidation of U(IV) from the NRZ's is constrained by the oxidation rate of U(IV) as well as iron sulfides, which can prevent oxidation of U(IV) by scavenging dissolved oxygen.

  5. EPA Method: Rapid Radiochemical Method for Americium-241, Radium-226, Plutonium-238/-239, Radiostronium, and Isotopic Uranium in Water for Environmental Restoration Following Homeland Security Events

    Science.gov (United States)

    SAM lists this method for the qualitative determination of Americium-241, Radium-226, Plutonium-238, Plutonium-239 and isotopic uranium in drinking water samples using alpha spectrometry and radiostrontium using beta counting.

  6. Fragment angular anisotropy in the {sup 232}Th(n,f) and {sup 238}U(n,f) reactions at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhov, Igor; Tutin, Gennady; Eismont, Vilen [V.G. Khlopin Radium Institute, Saint-Petersburg (Russian Federation); Onegin, Mikhail [Petersburg Nuclear Physics Institute of Russian Academy of Science, Gatchina (Russian Federation); Conde, Henri; Olsson, Nils [Uppsala Univ., Angstroem Laboratory, Dept. of Neutron Research, Uppsala (Sweden)

    2002-08-01

    Results of fragment angular anisotropy measurements are given for the {sup 232}Th(n,f) and {sup 238}U(n,f) reactions in the energy range 20-160 MeV. The energy dependence of the anisotropy is calculated in the context of the Halpern-Strutinsky's formalism. The observed difference in the fragment anisotropy of {sup 232}Th and {sup 238}U is discussed. (author)

  7. Isotopic production cross-sections and recoil velocities of spallation-fission fragments in the reaction 238U(1A GeV)+e

    CERN Document Server

    Pereira, J; Wlazlo, W; Benlliure, J; Casarejos, E; Armbruster, P; Bernas, M; Enqvist, T; Legrain, R; Leray, S; Rejmund, F; Mustapha, B; Schmidt, K.-H; Stéphan, C; Taïeb, J; Tassan-Got, L; Volant, C; Boudard, A; Czajkowski, S; 10.1103/PhysRevC.75.014602

    2007-01-01

    Fission fragments of 1A GeV 238U nuclei interacting with a deuterium target have been investigatedwith the Fragment Separator (FRS) at GSI (Darmstadt) by measuring their isotopicproduction cross-sections and recoil velocities. The results, along with those obtained recently forspallation-evaporation fragments, provide a comprehensive analysis of the spallation nuclear productionsin the reaction 238U(1A GeV)+d. Details about experiment performance, data reductionand results will be presented.

  8. Annual committed effective dose from olive oil (due to 238U, 232Th, and 222Rn) estimated for members of the Moroccan public from ingestion and skin application.

    Science.gov (United States)

    Misdaq, M A; Touti, R

    2012-03-01

    Olive oil is traditionally refined and widely consumed by Moroccan rural populations. Uranium (238U), thorium (232Th), radon (222Rn), and thoron (220Rn) contents were measured in various locally produced olive oil samples collected in rural areas of Morocco. These radionuclides were also measured inside various bottled virgin olive oils consumed by the Moroccan populations. CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs) were used. Annual committed effective doses due to 238U, 232Th, and 222Rn from the ingestion of olive oil by the members of the general public were determined. The maximum total committed effective dose due to 238U, 232Th, and 222Rn from the ingestion of olive oil by adult members of Moroccan rural populations was found equal to 5.9 µSv y-1. The influence of pollution due to building material dusts and phosphates on the radiation dose to workers from the ingestion of olive oil was investigated, and it was found that the maximum total committed effective dose due to 238U, 232Th, and 222Rn was on the order of 0.22 mSy y-1. Committed effective doses to skin due to 238U, 232Th, and 222Rn from the application of olive oil masks by rural women were evaluated. The maximum total committed effective dose to skin due to 238U, 232Th, and 222Rn was found equal to 0.07 mSy y-1 cm-2.

  9. 238U-230Th dating of chevkinite in high-silica rhyolites from La Primavera and Yellowstone calderas

    Science.gov (United States)

    Vazquez, Jorge A.; Velasco, Noel O.; Schmitt, Axel K.; Bleick, Heather A.; Stelten, Mark E.

    2014-01-01

    Application of 238U-230Th disequilibrium dating of accessory minerals with contrasting stabilities and compositions can provide a unique perspective on magmatic evolution by placing the thermochemical evolution of magma within the framework of absolute time. Chevkinite, a Th-rich accessory mineral that occurs in peralkaline and metaluminous rhyolites, may be particularly useful as a chronometer of crystallization and differentiation because its composition may reflect the chemical changes of its host melt. Ion microprobe 128U-230Th dating of single chevkinite microphenocrysts from pre- and post-caldera La Primavera, Mexico, rhyolites yields model crystallization ages that are within 10's of k.y. of their corresponding K-Ar ages of ca. 125 ka to 85 ka, while chevkinite microphenocrysts from a post-caldera Yellowstone, USA, rhyolite yield a range of ages from ca. 110 ka to 250 ka, which is indistinguishable from the age distribution of coexisting zircon. Internal chevkinite-zircon isochrons from La Primavera yield Pleistocene ages with ~5% precision due to the nearly two order difference in Th/U between both minerals. Coupling chevkinite 238U-230Th ages and compositional analyses reveals a secular trend of Th/U and rare earth elements recorded in Yellowstone rhyolite, likely reflecting progressive compositional evolution of host magma. The relatively short timescale between chevkinite-zircon crystallization and eruption suggests that crystal-poor rhyolites at La Primavera were erupted shortly after differentiation and/or reheating. These results indicate that 238U-230Th dating of chevkinite via ion microprobe analysis may be used to date crystallization and chemical evolution of silicic magmas.

  10. Probing the role of Skyrme interactions on the fission dynamics of the {sup 6}Li + {sup 238}U reaction

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ishita; Kumar, Raj; Sharma, Manoj K. [Thapar University, School of Physics and Materials Science, Patiala (India)

    2017-06-15

    The performance of selected five Skyrme forces (out of a set of 240), tested by Dutra et al., is analyzed in view of fusion-fission dynamics. These forces are assumed to perform better for neutron-rich systems, so the choice of the reaction is accordingly made by opting for a neutron-rich target in {sup 6}Li + {sup 238}U reaction. This reaction is diagnosed further in reference to fusion hindrance within the dynamical approach of the cluster-decay model (DCM). In order to reduce the computational time, three Skyrme forces are figured out with the criteria that these forces cover the barrier characteristics of the remaining two forces as well. The fission cross-sections are successfully addressed at low energies for the {sup 6}Li + {sup 238}U reaction. However, at relatively higher energies, the excitation functions show theoretical suppression with respect to experimental data, which may be associated with the possible existence of incomplete fusion (ICF). For ICF, we have considered that the {sup 6}Li broke into {sup 4}He + {sup 2}H, as mentioned in the experimental work. The calculations of ICF are carried out for the {sup 4}He + {sup 238}U reaction with the selected Skyrme forces at E{sub c.m.} = 26.20 and 27.51 MeV. These forces address the data nicely for the compound nucleus (CN) as well as ICF processes. Here, the NRAPR force seems to require lesser barrier modification as compared to the other forces, therefore it can be used as an alternate choice for calculating the interaction potential. Additionally, the prediction of cross-sections at lower energies has been done with DCM using the NRAPR force. The l-dependent % barrier modification of the Skyrme forces undertaken is also worked out in reference to fusion hindrance at below barrier energies. (orig.)

  11. Effect of Fe2+ Oxidation on the Removal of 238Pu from Neptunium Solution by Anion Exchange

    Energy Technology Data Exchange (ETDEWEB)

    KYSER, EDWARD

    2004-06-01

    The effect of ferrous sulfamate (FS) oxidation and variation in nitric acid concentration on the removal of {sup 238}Pu contamination from Np by the HB-Line anion exchange flowsheet has been tested. Significant rejection of {sup 238}Pu was observed by washing with a reductive wash solution containing 6.0 to 6.8 M nitric acid (HNO{sub 3}) with as little as 30% of the Fe{sup 2+} from the FS remaining in its reduced form. To achieve the desired 30% removal of {sup 238}Pu from the process, conditions should be controlled to maintain the Fe{sup 2+}/Fe{sup 3+} ratio in the reductive wash to be greater than 60%/40% (or 1.5). Since Fe{sup 2+} oxidation is strongly affected by temperature and nitric acid concentration, these parameters (as well as time after FS addition) need to be controlled to ensure predictable results. A shortened-height column was utilized in these tests to match changes in the plant equipment. Lab experiments scaled to plant batch sizes of 2000 g Np were observed with modest losses for ''up-flow'' washing. The following are recommended conditions for removing {sup 238}Pu from Np solutions by anion exchange in HB-Line: (1) Feed conditions: ''Up-flow'' 6.4-8.0 M HNO{sub 3}, 0.02 M hydrazine (N{sub 2}H{sub 4}), 0.05 M excess FS. (2) Reductive Wash conditions: ''Up-flow'' 6 Bed volumes (BV) of 6.4 M HNO{sub 3}, 0.05 M FS (minimum 0.03M Fe{sup 2+} during wash cycle), 0.05 M hydrazine, less than 1.8 mL/min/cm{sup 2} flowrate. (3) Decontamination Wash conditions: ''Up-flow'' 1-2 BV of 6.4-8.0 M HNO{sub 3}, no FS, no hydrazine, less than 1.8 mL/min/cm{sup 2} flowrate. (4) Elution conditions: ''Down-flow'' 0.17 M HNO{sub 3}, 0.05 M hydrazine, no FS.

  12. New Nuclide {sup 267}108 Produced by the {sup 238}U+{sup 34}S Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Lazarev, Y.A.; Lobanov, Y.V.; Oganessian, Y.T.; Tsyganov, Y.S.; Utyonkov, V.K.; Abdullin, F.S.; Iliev, S.; Polyakov, A.N.; Rigol, J.; Shirokovsky, I.V.; Subbotin, V.G.; Sukhov, A.M.; Buklanov, G.V.; Gikal, B.N.; Kutner, V.B.; Mezentsev, A.N.; Sedykh, I.M.; Vakatov, D.V. [Joint Institute for Nuclear Research, 141980 Dubna, Russian Federation (Russian Federation); Lougheed, R.W.; Wild, J.F.; Moody, K.J.; Hulet, E.K. [University of California, Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    1995-09-04

    In bombardments of {sup 238}U targets with 186-MeV {sup 34}S projectiles we discovered the {alpha}-decaying nuclide {sup 267}108 with a half-life of 19{sub {minus}10}{sup +29} ms, {ital E}{sub {alpha}}=9.74 to 9.87 MeV, and a production cross section of about 2.5 pb. The new nuclide was identified by measuring correlations in energy, time, and position to establish genetic links between its implantation in a position-sensitive silicon detector and subsequent {alpha} decay followed by {alpha} decays of known descendant nuclides.

  13. Mass-yield distributions in the reaction of /sup 56/Fe ions with /sup 238/U. [538 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Reus, U.; Habbestad Waetzig, A.M.; Esterlund, R.A.; Patzelt, P.; Grant, I.S.

    1977-07-25

    Radiochemical measurements of cross sections for 173 nuclides produced in the reaction of 538-MeV /sup 56/Fe ions with thick /sup 238/U targets were performed, and the mass-yield curve was determined. Seven components were resolved, corresponding to three reaction mechanisms: (1) quasielastic transfer (810 +- 160 mb); (2) quasifission (350 +- 55 mb); (3) fusion-fission (190 +- 30 mb). Comparison with data from other systems indicates that the fusion-fission cross section for heavy targets depends strongly on projectile mass and target- to projectile-mass ratio.

  14. Effective treatment of H838 human non-small cell lung carcinoma with a targeted cytotoxic somatostatin analog, AN-238.

    Science.gov (United States)

    Szereday, Zoltan; Schally, Andrew V; Szepeshazi, Karoly; Bajo, Ana-Maria; Hebert, Francine; Halmos, Gabor; Nagy, Attila

    2003-05-01

    The accumulation of radioactive somatostatin analog [111In]pentetreotide in non-small cell lung cancer (non-SCLC) during scintigraphy of patients provides a rationale for investigating the efficacy of somatostatin receptor-based chemotherapy in non-SCLC. Consequently, in this study, we evaluated the antitumor effects of cytotoxic somatostatin analog AN-238 on H838 human non-SCLC xenografted into nude mice in comparison with its cytotoxic radical, 2-pyrrolinodoxorubicin (AN-201). The expression of messenger RNA (mRNA) for human somatostatin receptor subtypes 2 (hsst2) and 5 (hsst5) in H838 cells, and tumors was also investigated using reverse-transcription polymerase chain reaction (RT-PCR). Somatostatin receptors on H838 tumors were characterized by ligand competition assay using radiolabeled somatostatin analog, RC-160. Three i.v. injections of AN-238 at 150 nmol/kg, given on days 1, 7 and 21, resulted in a significant (p<0.05) tumor growth inhibition, the final tumor volume being 60% smaller than in the controls. The tumor doubling time was also extended significantly (p<0.05) from 9.65+/-0.56 days in the controls to 17.52+/-3.3 days. Only one of 8 mice died due to toxicity. In contrast, cytotoxic radical AN-201 was ineffective and more toxic, killing 2 of 7 animals. mRNA for hsst2 was found in H838 xenografts, but not in H838 cells from which the xenografts originated. Interestingly, H838 cells grown in a special, serum-free medium did express mRNA for hsst2. mRNA for hsst5 was not found in any samples tested. Binding studies demonstrated the presence of high affinity (K(d) = 7.3+/-1.2 nM) binding sites for RC-160 with a mean maximal binding capacity (B(max)) of 953.3+/-45.3 fmol/mg protein. AN-238 at 3.14+/-0.93 nM concentration displaced 50% of radiolabeled RC-160 binding to somatostatin receptors in H838 tumors. Our results indicate that patients with inoperable non-SCLC may benefit from chemotherapy targeted to somatostatin receptors based on AN-238.

  15. Investigation of neutron-induced ternary fission of 238U and 235U with the NIFFTE time projection chamber

    Science.gov (United States)

    Kemnitz, A.; Klay, J. L.; Niffte Collaboration

    2017-09-01

    Ternary fission is a rare process in which a nucleus breaks up into three daughters rather than two. The most common outcome is two heavier fragments accompanied by an alpha particle, with the upper limit for the third daughter set by tri-partition of the nucleus into three nearly equal mass fragments. Tracked fission event data recorded by the NIFFTE collaboration for neutron-induced fission of 238U and 235U targets have been analyzed to determine average opening angles, fragment energies, and production rates as a function of neutron energy for ternary candidates. Preliminary results from these studies will be presented.

  16. Accurate isotopic fission yields of electromagnetically induced fission of 238U measured in inverse kinematics at relativistic energies

    Science.gov (United States)

    Pellereau, E.; Taïeb, J.; Chatillon, A.; Alvarez-Pol, H.; Audouin, L.; Ayyad, Y.; Bélier, G.; Benlliure, J.; Boutoux, G.; Caamaño, M.; Casarejos, E.; Cortina-Gil, D.; Ebran, A.; Farget, F.; Fernández-Domínguez, B.; Gorbinet, T.; Grente, L.; Heinz, A.; Johansson, H.; Jurado, B.; Kelić-Heil, A.; Kurz, N.; Laurent, B.; Martin, J.-F.; Nociforo, C.; Paradela, C.; Pietri, S.; Rodríguez-Sánchez, J. L.; Schmidt, K.-H.; Simon, H.; Tassan-Got, L.; Vargas, J.; Voss, B.; Weick, H.

    2017-05-01

    SOFIA (Studies On Fission with Aladin) is a novel experimental program, dedicated to accurate measurements of fission-fragment isotopic yields. The setup allows us to fully identify, in nuclear charge and mass, both fission fragments in coincidence for the whole fission-fragment range. It was installed at the GSI facility (Darmstadt), to benefit from the relativistic heavy-ion beams available there, and thus to use inverse kinematics. This paper reports on fission yields obtained in electromagnetically induced fission of 238U.

  17. Uranium contents and (235)U/(238)U atom ratios in soil and earthworms in western Kosovo after the 1999 war.

    Science.gov (United States)

    Di Lella, L A; Nannoni, F; Protano, G; Riccobono, F

    2005-01-20

    The uranium content and (235)U/(238)U atom ratio were determined in soils and earthworms of an area of Kosovo (Djakovica garrison), heavily shelled with depleted uranium (DU) ammunition during the 1999 war. The aim of the study was to reconstruct the small-scale distribution of uranium and assess the influence of the DU added to the surface environment. The total uranium concentration and the (235)U/(238)U ratio of topsoils showed great variability and were inversely correlated. The highest uranium levels (up to 31.47 mg kg(-1)) and lowest (235)U/(238)U ratios (minimum 0.002147) were measured in topsoils collected inside, or very close to, the clusters of DU penetrator holes. Regarding the fractionation of uranium in the surface soils, the uranium concentrations in the soluble and exchangeable fractions increased as the total uranium concentration of the topsoils increased. High and rather uniform percentage contents of uranium (24-36%) were associated with the poorly crystalline iron oxide phases of soils. In the U-enriched soils the elevated levels of the element were probably due to the presence of very small, unevenly distributed oxidized DU particles. The total uranium concentration in earthworms was in the range 0.142-0.656 mg kg(-1), with the highest concentrations in Lumbricus terrestris. The juveniles of all three studied species seemed to accumulate uranium more than adults, probably due to age-related differences in metabolism. The (235)U/(238)U ratio in the earthworms was variable (0.005241-0.007266) and independent of both the total uranium contents in soils and the absolute uranium levels in the animals. Bioconcentration was greater at lower U concentrations in soil, probably due to an increasing rate of elimination of uranium by the earthworms as the soil contents of the element increase. The results of this study clearly indicate that DU was added to the soil of the study area. Nevertheless, the phenomenon was very limited spatially and the total

  18. The transport characteristics of {sup 238}U, {sup 232}Th, {sup 226}Ra, and {sup 40}K in the production cycle of phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yoon Hee; Lim, Jong Myoung; Ji, Young Yong; Chung, Kun Ho; Kang, Mun Ja [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-03-15

    Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., 238U and 226Ra), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, 238U, 232Th, 226Ra, and 40K levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of 238U, 232Th, 226Ra, and 40K. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. The concentration ratios of 226Ra and 238U in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was 40K, and the median 40K activity was 8.972 Bq·g−1 and 1.496 Bq·g−1, respectively. For the 238U series, the activity of 238U and 226Ra was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Although the activity of 40K in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of 226Ra and 238U in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing.

  19. Spectral interference corrections for the measurement of (238)U in materials rich in thorium by a high resolution gamma-ray spectrometry.

    Science.gov (United States)

    Yücel, H; Solmaz, A N; Köse, E; Bor, D

    2009-11-01

    In this study, the spectral interferences are investigated for the analytical peaks at 63.3 keV of (234)Th and 1001.0 keV of (234m)Pa, which are often used in the measurement of (238)U activity by the gamma-ray spectrometry. The correction methods are suggested to estimate the net peak areas of the gamma-rays overlapping the analytical peaks, due to the contribution of (232)Th that may not be negligible in materials rich in natural thorium. The activity results for the certified reference materials (CRMs) containing U and Th were measured with a well type Ge detector. The self-absorption and true coincidence-summing (TCS) effects were also taken into account in the measurements. It is found that ignoring the contributions of the interference gamma-rays of (232)Th and (235)U to the mixed peak at 63.3 keV of (234)Th ((238)U) leads to the remarkably large systematic influence of 0.8-122% in the measured (238)U activity, but in case of ignoring the contribution of (232)Th via the interference gamma-ray at 1000.7 keV of (228)Ac to the mixed peak at 1001 keV of (234m)Pa ((238)U) results in relatively smaller systematic influence of 0.05-3%, depending on thorium contents in the samples. The present results showed that the necessary correction for the spectral interferences besides self-absorption and TCS effects is also very important to obtain more accurate (238)U activity results. Additionally, if one ignores the contribution of (232)Th to both (238)U and (40)K activities in materials, the maximum systematic influence on the effective radiation dose is estimated to be ~6% and ~1% via the analytical peaks at 63.3 and 1001 keV for measurement of the (238)U activity, respectively.

  20. Determination of {sup 235}U/{sup 238}U ratio by low energy gamma rays. An experimental evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Mirashi, N.N.; Chakraborty, S.; Aggarwal, S.K. [Bhabha Atomic Reseach Centre, Mumbai (India). Fuel Chemistry Div.

    2011-07-01

    Determination of the {sup 235}U/{sup 238}U atom ratio is required for various applications. Thermal ionization mass spectrometry (TIMS) is generally used for this purpose since the method gives most precise results. However, the method has limitations like elaborate sample preparation and high cost. Thus, an alternative methodology based on low energy photon spectrometry (LEPS) was developed and tested using routine samples. It involves the determination of gamma ({gamma}) activity at gamma energies of 63.3, 92.8, 143.6, and 185.7 keV in isotopic standard solutions of uranium and different enriched uranium sample solutions. The method is fast as it does not involve chemical treatment as in TIMS. In this paper, a comparative evaluation of thermal ionization mass spectrometry and low energy photon spectrometry is reported for the determination of the {sup 235}U/{sup 238}U atom ratio. The results obtained by the two systems compare well with each other within the statistical uncertainties of each system. Between the two, low energy photon spectrometry will be useful for rapid analysis of routine samples of enriched uranium. (orig.)

  1. Measurements of /sup 234/U, /sup 238/U and /sup 230/Th in excreta of uranium-mill crushermen

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.R.; Jackson, P.O.; Brodacynski, G.G.; Scherpelz, R.I.

    1982-07-01

    Uranium and thorium levels in excreta of uranium mill crushermen who are routinely exposed to airborne uranium ore dust were measured. The purpose was to determine whether /sup 230/Th was preferentially retained over either /sup 234/U or /sup 238/U in the body. Urine and fecal samples were obtained from fourteen active crushermen with long histories of exposure to uranium ore dust, plus four retired crushermen and three control individuals for comparison. Radiochemical procedures were used to separate out the uranium and thorium fractions, which were then electroplated on stainless steel discs and assayed by alpha spectrometry. Significantly greater activity levels of /sup 234/U and /sup 238/U were measured in both urine and fecal samples obtained from uranium mill crushermen, indicating that uranium in the inhaled ore dust was cleared from the body with a shorter biological half-time than the daughter product /sup 230/Th. The measurements also indicated that uranium and thorium separate in vivo and have distinctly different metabolic pathways and transfer rates in the body. The appropriateness of current ICRP retention and clearance parameters for /sup 230/Th in ore dust is questioned.

  2. Effect of U-238 and U-235 cross sections on nuclear characteristics of fast and thermal reactors

    Energy Technology Data Exchange (ETDEWEB)

    Akie, Hiroshi; Takano, Hideki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kaneko, Kunio

    1997-03-01

    Benchmark calculation has been made for fast and thermal reactors by using ENDF/B-VI release 2(ENDF/B-VI.2) and JENDL-3.2 nuclear data. Effective multiplication factors (k{sub eff}s) calculated for fast reactors calculated with ENDF/B-VI.2 becomes about 1% larger than the results with JENDL-3.2. The difference in k{sub eff} is caused mainly from the difference in inelastic scattering cross section of U-238. In all thermal benchmark cores, ENDF/B-VI.2 gives smaller multiplication factors than JENDL-3.2. In U-235 cores, the difference is about 0.3%dk and it becomes about 0.6% in TCA U cores. The difference in U-238 data is also important in thermal reactors, while there are found 0.1-0.3% different v values of U isotopes in thermal energy between ENDF/B-VI.2 and JENDL-3.2. (author)

  3. Development of a method for multielemental determination in water by EDXRF with radioisotopic source of {sup 238}Pu

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, C.; Estévez, J.; Montero, A.; Pupo, I.; Herrero, Z.; Leyva, D.; Arteche, J.; Varcárcel, L. [Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear (CEADEN), (Cuba); Van Espen, P. [University of Amberes, (Belgium); Santos Júnior, J. A. dos, E-mail: cserrano@cedaen.edu.cu [Universidade Federal de Pernambuco (UFPE), Recife (Brazil)

    2017-07-01

    A method for determination of Cr, Fe, Co, Ni, Cu, Zn, Hg and Pb in waters by Energy Dispersive X Ray Fluorescence (EDXRF) was implemented, using a radioisotopic source of {sup 238}Pu. For previous concentration was employed a procedure including a coprecipitation step with ammonium pyrrolidine dithiocarbamate (APDC) as quelant agent, the separation of the phases by filtration, the measurement of filter by EDXRF and quantification by a thin layer absolute method. Sensitivity curves for K and L lines were obtained respectively. The sensitivity for most elements was greater by an order of magnitude in the case of measurement with a source of {sup 238}Pu instead of {sup 109}Cd, which means a considerable decrease in measurement times. The influence of the concentration in the precipitation efficiency was evaluated for each element. In all cases the recoveries are close to 100%, for this reason it can be affirmed that the method of determination of the studied elements is quantitative. Metrological parameters of the method such as trueness, precision, detection limit and uncertainty were calculated. A procedure to calculate the uncertainty of the method was elaborated; the most significant source of uncertainty for the thin layer EDXRF method is associated with the determination of instrumental sensitivities. The error associated with the determination, expressed as expanded uncertainty (in %), varied from 15.4% for low element concentrations (2.5-5 μg/L) to 5.4% for the higher concentration range (20-25 μg/L). (author)

  4. Fission Fragment Angular Distribution measurements of 235U and 238U at CERN n_TOF facility

    Science.gov (United States)

    Leal-Cidoncha, E.; Durán, I.; Paradela, C.; Tarrío, D.; Leong, L. S.; Tassan-Got, L.; Audouin, L.; Altstadt, S.; Andrzejewski, J.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M. A.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Dzysiuk, N.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A. R.; Giubrone, G.; Gómez-Hornillos, M. B.; Gonçalves, I. F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Hernández-Prieto, A.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Kokkoris, M.; Krtička, M.; Kroll, J.; Lampoudis, C.; Langer, C.; Lederer, C.; Leeb, H.; Lo Meo, S.; Losito, R.; Mallick, A.; Manousos, A.; Marganiec, J.; Martínez, T.; Massimi, C.; Mastinu, P. F.; Mastromarco, M.; Meaze, M.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Mondelaers, W.; Pavlik, A.; Perkowski, J.; Plompen, A.; Praena, J.; Quesada, J. M.; Rauscher, T.; Reifarth, R.; Riego, A.; Robles, M. S.; Roman, F.; Rubbia, C.; Sabaté-Gilarte, M.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Tagliente, G.; Tain, J. L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M. J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T.; Žugec, P.

    2016-03-01

    Neutron-induced fission cross sections of 238U and 235U are used as standards in the fast neutron region up to 200 MeV. A high accuracy of the standards is relevant to experimentally determine other neutron reaction cross sections. Therefore, the detection effciency should be corrected by using the angular distribution of the fission fragments (FFAD), which are barely known above 20 MeV. In addition, the angular distribution of the fragments produced in the fission of highly excited and deformed nuclei is an important observable to investigate the nuclear fission process. In order to measure the FFAD of neutron-induced reactions, a fission detection setup based on parallel-plate avalanche counters (PPACs) has been developed and successfully used at the CERN-n_TOF facility. In this work, we present the preliminary results on the analysis of new 235U(n,f) and 238U(n,f) data in the extended energy range up to 200 MeV compared to the existing experimental data.

  5. Determination of specific concentrations of {sup 40}K, {sup 238}U and {sup 232}Th in mineral fertilizer samples

    Energy Technology Data Exchange (ETDEWEB)

    Garcez, Ricardo W.D.; Lopes, Jose M.; Silva, Ademir X., E-mail: r.w.o.g@fisica.if.uff.br, E-mail: ademir@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Domingues, Alessandro M.; Lima, Marco F. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2015-07-01

    The use of fertilizer is an established practice worldwide to promote agricultural productivity increased without increasing the planted area, resulting in native forests protection and increase of the food availability. Some kinds of fertilizer have in their chemical composition some radionuclides due the origin of its feedstock, such as {sup 238}U, the {sup 232}Th, and their descendants, beyond {sup 40}K. Knowledge of the radioactivity levels in the environment is great importance to know the gamma radiation dose that the human being is exposed. For identification and quantitation of radionuclides, it was used gamma spectrometry where HPGe detector was used to obtain the spectra, and LabSOCS software for calculating the detection efficiency for each energy. The values of {sup 232}Th specific concentrations ranged from 4.1 to 368.1 Bq.Kg{sup -1}, the values of {sup 238}U specific concentrations ranged from 16.0 to 647.7 Bq.Kg{sup -1} and {sup 40}K specific concentrations ranged from 19.1 to 12713 Bq.Kg{sup -1}. Concentrations of values are consistent with those found in literature. (author)

  6. Tumor Necrosis Factor-Alpha Gene Promoter −308G/A and −238G/A Polymorphisms in Mexican Patients with Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Juan Manuel Guzmán-Flores

    2011-01-01

    Full Text Available The association between some Tumor necrosis factor-alpha (TNF-α promoter polymorphisms and Type 2 diabetes mellitus (T2DM remains controversial. Ethnic differences may play a role in these conflicting results. The aim of this study was to investigate the association between −308G/A and −238G/A polymorphisms located in the promoter region of the TNF-α gene and T2DM in Mexican mestizo patients. Nine hundred four individuals (259 patients with T2DM and 645 controls were genotyped for the −308G/A and −238G/A polymorphisms by PCR—RFLP. We found that the −238A allele increased the risk of developing T2DM in Mexican patients (OR = 1.57, 95% CI: 1.07–2.29; p = 0.018. Moreover, we found that the frequency of the GA haplotype (created by the −308G and −238A alleles was significantly increased in patients with T2DM when compared with controls (OR = 1.56, 95% CI: 1.05–2.31; p = 0.026. Our results suggest that the −238G/A polymorphism and a specific haplotype (GA are genetic risk factors for the development of T2DM in Mexican population.

  7. Towards A Modern Calibration Of The 238U/235U Paleoredox Proxy: Apparent Uranium Isotope Fractionation Factor During U(VI)-U(IV) Reduction In The Black Sea

    Science.gov (United States)

    Rolison, J. M.; Stirling, C. H.; Middag, R.; Rijkenberg, M. J. A.; De Baar, H. J. W.

    2015-12-01

    The isotopic compositions of redox-sensitive metals, including uranium (U), in marine sediments have recently emerged as powerful diagnostic tracers of the redox state of the ancient ocean-atmosphere system. Interpretation of sedimentary isotopic information requires a thorough understating of the environmental controls on isotopic fractionation in modern anoxic environments before being applied to the paleo-record. In this study, the relationship between ocean anoxia and the isotopic fractionation of U was investigated in the water column and sediments of the Black Sea. The Black Sea is the world's largest anoxic basin and significant removal of U from the water column and high U accumulation rates in modern underlying sediments have been documented. Removal of U from the water column occurs during the redox transition of soluble U(VI) to relatively insoluble U(IV). The primary results of this study are two-fold. First, significant 238U/235U fractionation was observed in the water column of the Black Sea, suggesting the reduction of U induces 238U/235U fractionation with the preferential removal of 238U from the aqueous phase. Second, the 238U/235U of underlying sediments is related to the water column through the isotope fractionation factor of the reduction reaction but is influenced by mass transport processes. These results provide important constraints on the use of 238U/235U as a proxy of the redox state of ancient oceans.

  8. BetaScint{trademark} fiber-optic sensor for detecting strontium-90 and uranium-238 in soil. Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    Accurate measurements of radioactivity in soils contaminated with Strontium-90 (Sr-90) or Uranium-238 (U-238) are essential for many DOE site remediation programs. These crucial measurements determine if excavation and soil removal is necessary, where remediation efforts should be focused, and/or if a site has reached closure. Measuring soil contamination by standard EPA laboratory methods typically takes a week (accelerated analytical test turnaround) or a month (standard analytical test turnaround). The time delay extends to operations involving heavy excavation equipment and associated personnel which are the main costs of remediation. This report describes an application of the BetaScint{trademark} fiber-optic sensor that measures Sr-90 or U-238 contamination in soil samples on site in about 20 minutes, at a much lower cost than time-consuming laboratory methods, to greatly facilitate remediation. This report describes the technology, its performance, its uses, cost, regulatory and policy issues, and lessons learned.

  9. Analysis of {sup 209} Bi and {sup 238} U photofission cross section in the quasi-deuteron region of photonuclear absorption

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, O.A.P. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Terranova, M.L. [Istituto Nazionale di Fisica Nucleare, Rome (Italy)

    1992-12-31

    An analysis of the photofission reactions in the quasi-deuteron energy range of photonuclear absorption ({approx} 30-140 MeV) has been performed for {sup 209} Bi and {sup 238} U nuclei. Experimental cross section data available in the literature have been compared with calculated values obtained from a model in which the incoming photon is assumed to be absorbed by a neutron-proton pair (Levinger`s quasi-deuteron photoabsorption), followed by a mechanism of evaporation-fission competition for the excited residual nuclei. The model has been shown to reproduce the main experimental features of {sup 209} Bi and {sup 238} U photofission cross section, although unexplained differences still remain in the case of {sup 238} U-fission by 30-50 MeV incident photons. (author). 49 refs, 10 figs, 2 tabs.

  10. Cancer pain management at a tertiary care cancer center in India--a retrospective analysis of 3,238 patients.

    Science.gov (United States)

    Bhatnagar, Sushma; Mishra, Seema; Srikanti, Madhurima; Gupta, Deepak

    2008-01-01

    Effective pain control is essential for the management of patients with cancer. About 70-80 percent of patients with cancer present in an advanced stage of disease. Patients with advanced cancer frequently experience intractable pain, with diverse symptoms that can make daily living impossible and affect the quality of life. This article reports the management of 3,238 patients with cancer pain over a period of five years. Nearly 89.6 percent patients had good pain relief with Visual Analogue Scale score less than 3. These promising results were achieved by careful patient assessment, close liaison with clinicians from other specialties, and using a variety of analgesic regimen including oral analgesics, anesthetic procedures, psychological interventions, and supportive care. However, the main stay of treatment was oral analgesics, following the principles of World Health Organization ladder, with continuing follow-up.

  11. Production cross section of neutron-rich Pb and Bi isotopes in the fragmentation of 238U

    CERN Document Server

    Alvarez-Pol, H; Benlliure, J; Casarejos, E; Cortina-GilL, D; Napolitani, P; Enqvist, T; Schmidt, K-H; Yordanov, O; Junghans, A.R; Fernández, B; Pereira, P; Jurado, B; Rejmund, F; 10.1140/epja/i2009-10856-8

    Neutron-rich lead and bismuth isotopes have been produced by cold-fragmentation reactions induced by 238U projectiles at 1 AGeV impinging on a beryllium target. The high-resolving power FRagment Separator at GSI allowed us to identify and determine the production cross sections of 22 nuclei, nine of them for the first time 215Pb, 216Pb, 217Pb, 218Pb and 217Bi, 218Bi, 219Bi, 220Bi, 221Bi, 222Bi. These data are compared to other previously measured cross sections in similar reactions and model calculations. The validation of the codes is of utmost importance for estimating of the new limits accessible with the new generation radioactive beam facilities.

  12. Alpha and conversion electron spectroscopy of 238,239Pu and 241Am and alpha-conversion electron coincidence measurements

    Energy Technology Data Exchange (ETDEWEB)

    Dion, Michael P.; Miller, Brian W.; Warren, Glen A.

    2016-09-01

    A technique to determine the isotopics of a mixed actinide sample has been proposed by measuring the coincidence of the alpha particle during radioactive decay with the conversion electron (or Auger) emitted during the relaxation of the daughter isotope. This presents a unique signature to allow the deconvolution of isotopes that possess overlapping alpha particle energy. The work presented here are results of conversion electron spectroscopy of 241Am, 238Pu and 239Pu using a dual-stage peltier-cooled 25 mm2 silicon drift detector. A passivated ion implanted planar silicon detector provided measurements of alpha spectroscopy. The conversion electron spectra were evaluated from 20–55 keV based on fits to the dominant conversion electron emissions, which allowed the relative conversion electron emission intensities to be determined. These measurements provide crucial singles spectral information to aid in the coincident measurement approach.

  13. Study of Photon Strength Functions of Actinides: the case of U-235, Np-238 and Pu-241

    CERN Document Server

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

    2011-01-01

    The decay from excited levels in medium and heavy nuclei can be described in a statistical approach by means of Photon Strength Functions and Level Density distributions combined with the theory of the compound. The study of electromagnetic cascades following neutron capture by means of high efficiency detectors has been shown to be well suited for probing the properties of the Photon Strength Function of heavy (high level density) and/or radioactive (high background) nuclei. In this work we have investigated for the first time the validity of the recommended PSF for actinides, in particular 235U, 238Np and 241Pu. Our study includes the search for resonance structures in the PSF below Sn and draws conclusions regarding their existence and their characteristics in terms of energy, width and electromagnetic nature.

  14. The estuarine chemistry and isotope systematics of 234,238U in the Amazon and Fly Rivers

    Science.gov (United States)

    Swarzenski, P.; Campbell, P.; Porcelli, D.; McKee, B.

    2004-01-01

    Natural concentrations of 238U and ??234U values were determined in estuarine surface waters and pore waters of the Amazon and Fly (Papua New Guinea) Rivers to investigate U transport phenomena across river-dominated land-sea margins. Discharge from large, tropical rivers is a major source of dissolved and solid materials transported to the oceans, and are important in defining not only oceanic mass budgets, but also terrestrial weathering rates. On the Amazon shelf, salinity-property plots of dissolved organic carbon, pH and total suspended matter revealed two vastly contrasting water masses that were energetically mixed. In this mixing zone, the distribution of uranium was highly non-conservative and exhibited extensive removal from the water column. Uranium removal was most pronounced within a salinity range of 0-16.6, and likely the result of scavenging and flocculation reactions with inorganic (i.e., Fe/Mn oxides) and organic colloids/particles. Removal of uranium may also be closely coupled to exchange and resuspension processes at the sediment/water interface. An inner-shelf pore water profile indicated the following diagenetic processes: extensive (???1 m) zones of Fe(III) - and, to a lesser degree, Mn(IV) - reduction in the absence of significant S(II) concentrations appeared to facilitate the formation of various authigenic minerals (e.g., siderite, rhodocrosite and uraninite). The pore water dissolved 238U profile co-varied closely with Mn(II). Isotopic variations as evidenced in ??234U pore waters values from this site revealed information on the origin and history of particulate uranium. Only after a depth of about 1 m did the ??234U value approach unity (secular equilibrium), denoting a residual lattice bound uranium complex that is likely an upper-drainage basin weathering product. This suggests that the enriched ??234U values represent a riverine surface complexation product that is actively involved in Mn-Fe diagenetic cycles and surface

  15. Radioactivity of 238U, 232Th, 40K, and 137Cs and assessment of depleted uranium in soil of the Musandam Peninsula, Sultanate of Oman

    OpenAIRE

    SALEH, Ibrahim Hindawy

    2014-01-01

    238U, 232Th, 40K, and 137Cs radioactivities were determined in soil samples collected from the Musandam Peninsula, Sultanate of Oman, using a high resolution gamma-ray spectroscopy system. In addition, total uranium was measured in selected soil samples by inductively coupled plasma optical emission spectroscopy (ICP-OES). The averages of radioactivity levels in the soil for 238U, 232Th, and 40K were 14.42 Bq kg-1, 9.95 Bq kg-1, 158.21 Bq kg-1, and 2770 Bq m-2 for 137Cs, respectively...

  16. Entwicklung einer aktiven 238Uran(VI)-fluorid-Detektor-Kammer für Präzisionsexperimente in der photoneninduzierten Spaltung am S-DALINAC

    OpenAIRE

    Eckardt, Christian

    2013-01-01

    Der am S-DALINAC installierte Injektor spinpolarisierter Elektronen SPIN ermöglicht den Einsatz zirkular polarisierter Bremsstrahlung mit einem hohen Polarisationsgrad in der Nähe der Endpunktsenergie für die Suche nach paritätsverletzenden Effekten in der Vorwärts-Rückwärts-Asymmetrie des leichten und schweren Spaltfragmentes der photoneninduzierten Spaltung an 238U. Zur Steigerung der Luminosität wurde im Rahmen dieser Arbeit eine aktive 238Uran(VI)-fluorid-Detektor-Kammer nach dem Prin...

  17. Transfer of {sup 40}K, {sup 238}U, {sup 210}Pb, and {sup 210}Po from soil to plant in various locations in south of Syria

    Energy Technology Data Exchange (ETDEWEB)

    Al-Masri, M.S. [Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic)], E-mail: scientific1@aec.org.sy; Al-Akel, B.; Nashawani, A.; Amin, Y.; Khalifa, K.H.; Al-Ain, F. [Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic)

    2008-02-15

    Transfer factors of {sup 40}K, {sup 238}U, {sup 210}Pb, and {sup 210}Po from soil to some agriculture crops in various locations in south of Syria (Dara'a and Assuwaydaa districts) have been determined. Soil and vegetable crops (green pepper, cucumber, tomato, and eggplant), legumes crops (lentil, chickpea, and broad bean), fruit trees (apple, grape, and olives) and cereals (barley and wheat) were collected and analyzed for {sup 238}U, {sup 210}Pb, and {sup 210}Po. The results have shown that higher transfer factors (calculated as Bq kg{sup -1} dry wt. plant material per Bq kg{sup -1} dry wt. soil) for {sup 210}Po, {sup 210}Pb and {sup 238}U were observed in vegetable leaves than fruits and cereals leaves; the highest values of transfer factor (TF) for {sup 238}U were found to be 0.1 for straw of chickpea. Transfer factors for {sup 210}Po varied between 2.8 x 10{sup -2} and 2 in fruits of eggplant and grain of barley, respectively. In addition, several parameters affecting transfer factors of the radionuclides were evaluated. The results can be considered as base values for TF of natural radionuclides in the region.

  18. Measurement of Fragment Mass Distributions in Neutron-induced Fission of {sup 238}U and {sup 232}Th at Intermediate Energies

    Energy Technology Data Exchange (ETDEWEB)

    Simutkin, V.D. [Uppsala University, P.O Box 525, SE-751 20 Uppsala (Sweden)

    2008-07-01

    Conceptual analysis of accelerator-driven systems assumes extensive use of nuclear data on neutron-induced reactions at intermediate energies. In particular, information about the fission fragment yields from the {sup 238}U(n,f) and {sup 232}Th(n,f) reactions is of particular interest at neutron energies from 10 to 200 MeV. However, there is a lack of such data for both {sup 238}U and {sup 232}Th. Up to now, the intermediate energy measurements have been performed for {sup 238}U only, and there are no data for the {sup 232}Th(n,f) reaction. The aim of the work is to provide such data. Fission fragment mass distributions for the {sup 232}Th(n,f) and {sup 238}U(n,f) reactions have been measured for the incident neutron energies 32.8 MeV, 45.3 MeV and 59.9 MeV. The experiments have been performed at the neutron beam facility of the Universite Catholique de Louvain, Belgium. A multi-section Frisch-gridded ionization chamber has been used as a fission fragment detector. The data obtained have been interpreted in terms of the multimodal random neck-rupture model (MMRNRM). (authors)

  19. INDEPENDENT AND CUMULATIVE YIELDS OF VERY NEUTRON-RICH NUCLEI IN 20 MEV P-INDUCED AND 18-41 MEV D-INDUCED FISSION OF U-238

    NARCIS (Netherlands)

    LEINO, M; JAUHO, PP; AYSTO, J; DECROCK, P; DENDOOVEN, P; ESKOLA, K; HUYSE, M; JOKINEN, A; PARMONEN, JM; PENTTILA, H; REUSEN, G; TASKINEN, P; VANDUPPEN, P; WAUTERS, J

    Independent and cumulative yields in nearly symmetric fission have been measured for the first time by bombarding U-238 with 20-MeV protons and with 18-, 25-, and 41-MeV deuterons. Isobaric charge dispersion has been determined in the A = 110, A = 112, and A = 114 mass chains and, from asymmetric

  20. Dissolution rates of /sup 238/PuO/sub 2/ and /sup 239/PuO/sub 2/ in 1M perchloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Matlack, G.M.; Patterson, J.H.; Nelson, G.B.; Waterbury, G.R.

    1976-12-01

    The dissolution rate of /sup 238/PuO/sub 2/ and /sup 239/PuO/sub 2/ in 1M HClO/sub 4/ was measured over a period of 200 days. When equal (150-..mu..g/l) masses of the oxides were compared, /sup 238/Pu was found to be released approximately five times faster than /sup 239/Pu. At the 10-..mu..Ci/ml activity level, /sup 238/Pu was released 100 times faster than /sup 239/Pu. The difference in dissolution rates is attributed to the difference in alpha particle specific activity of the two materials which causes significantly greater radiation damage in /sup 238/PuO/sub 2/ than in /sup 239/PuO/sub 2/. The rate difference also may be affected by particle size and total oxide mass in the dissolution system. The results of these studies agree with data from earlier investigations in distilled water and simulated body fluid solvents.

  1. Soil to plant transfer of {sup 238}U, {sup 226}Ra and {sup 232}Th on a uranium mining-impacted soil from southeastern China

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.B. [Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Institute of Natural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 12 Zhongguanchun Road, Beijing 100081 (China); Zhu, Y.G. [Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)]. E-mail: ygzhu@mail.rcees.ac.cn; Hu, Q.H. [Chemical Biology and Nuclear Science Division, Lawrence Livermore National Laboratory, PO Box 808, MS L-231, Livermore, CA 94550 (United States)

    2005-07-01

    Both soil and plant samples of nine different plant species grown in soils from southeastern China contaminated with uranium mine tailings were analyzed for the plant uptake and translocation of {sup 238}U, {sup 226}Ra and {sup 232}Th. Substantial differences were observed in the soil-plant transfer factor (TF) among these radionuclides and plant species. Lupine (Lupinus albus) exhibited the highest uptake of {sup 238}U (TF value of 3.7x10{sup -2}), while Chinese mustard (Brassica chinensis) had the least (0.5x10{sup -2}). However, in the case of {sup 226}Ra and {sup 232}Th, the highest TFs were observed for white clover (Trifolium pratense) (3.4x10{sup -2}) and ryegrass (Lolium perenne) (2.1x10{sup -3}), respectively. {sup 232}Th in the tailings/soil mixture was less available for plant uptake than {sup 226}Ra or {sup 238}U, and this was especially evident for Chinese mustard and corn (Zea mays). The root/shoot (R/S) ratios obtained for different plants and radionuclides shown that Indian mustard had the smallest R/S ratios for both {sup 226}Ra (5.3{+-}1.2) and {sup 232}Th (5.3{+-}1.7), while the smallest R/S ratio for {sup 238}U was observed in clover (2.8{+-}0.9)

  2. The activity concentrations of 40K, 226Ra, 232Th, 238U and 7Be in moss from spas in eastern Serbia in the period 2000-2012

    Directory of Open Access Journals (Sweden)

    Čučulović Ana

    2014-01-01

    Full Text Available In this work we present the activity concentrations of natural radionuclides 40K, 226Ra, 232Th, 238U and 7Be in mosses. One hundred and sixty-seven moss samples were collected between 2001 and 2012 from the territory of the Sokobanja, Banja Jošanica and Gamzigradska Banja spas. They were classified into 23 species. The activity concentrations (Bq/kg in moss from Sokobanja spa were: 40K 25-427; 226Ra 0.3-36; 232Th 1.0-37; 238U 0.4-28 and 7Be 29-210; from Banja Jošanica spa they were: 40K 90-242; 226Ra 2.4-11.7; 232Th 2.0-12.7; 238U 1.6-11.3 and 7Be 142-212; Gamzigradska Banja spa: 40K 95-351; 226Ra 8.0-21; 232Th 5.1-19; 238U 6.7-18 and 7Be 20-144. The activity concentrations of dominant natural radionuclides (potassium, radium, thorium and uranium in the moss samples were within the usual ranges for the territory of Serbia. [Projekat Ministarstva nauke Republike Srbije, br. III 43009

  3. No measurable changes in (238)U/(235)U due to desorption-adsorption of U(VI) from groundwater at the Rifle, Colorado, integrated field research challenge site.

    Science.gov (United States)

    Shiel, Alyssa E; Laubach, Parker G; Johnson, Thomas M; Lundstrom, Craig C; Long, Philip E; Williams, Kenneth H

    2013-03-19

    Groundwater samples were collected from the Integrated Field Research Challenge field site in Rifle, Colorado, over the course of a bicarbonate-induced U desorption-adsorption experiment. Uranium concentrations and high precision U isotopic compositions ((238)U/(235)U) of these groundwater samples were determined and used to assess the impact of bicarbonate-induced U(VI) desorption from contaminated sediments on the (238)U/(235)U of groundwater. The (238)U/(235)U of groundwater was not significantly impacted by bicarbonate-induced desorption of U(VI) from mineral surfaces or by adsorption of advecting U(VI) from upgradient locations onto those surfaces after the treatment. Assuming this absence of a significant shift in U isotopic composition associated with desorption-adsorption applies to other systems, reduction of U(VI) to U(IV) is expected to be the dominant source of U isotopic fractionation associated with removal of U(VI) from pore water as a result of natural and stimulated reductive pathways. Thus, changes in the (238)U/(235)U composition of uranium-bearing fluids should be useful in quantifying the extent of reduction.

  4. Crystallization and preliminary X-ray diffraction study of the class A beta-lactamase SED-1 and its mutant SED-G238C from Citrobacter sedlakii.

    Science.gov (United States)

    Petrella, S; Pernot, L; Sougakoff, W

    2004-01-01

    SED-1, a class A beta-lactamase from Citrobacter sedlakii, is a CTX-M-type extended-spectrum beta-lactamase that has the ability to hydrolyze expanded-spectrum cephalosporins such as cefotaxime. SED-1 and a SED mutant in which Gly238 has been replaced by a cysteine, forming a disulfide bridge with the other Cys residue located at position 69 (SED-G238C), have been crystallized. The crystals belong to the monoclinic space group C2, with unit-cell parameters a = 188.09, b = 73.65, c = 105.41 A, beta = 121.67 degrees for SED-1 and a = 187.64, b = 73.2, c = 103.89 A, beta = 121.89 degrees for the SED-G238C mutant. X-ray diffraction data were collected to maximum resolutions of 2.4 A for SED-1 and 2.0 A for SED-G238C.

  5. Internal tides and sediment dynamics in the deep sea-Evidence from radioactive Th-234/U-238 disequilibria

    Energy Technology Data Exchange (ETDEWEB)

    Turnewitsch, R. [Scottish Assoc Marine Sci, Dunstaffnage Marine Lab, Oban PA37 1QA, Argyll (United Kingdom); Turnewitsch, R.; Waniek, J.J. [Balt Sea Res Inst Warnemunde, D-18119 Rostock (Germany); Reyss, J.L. [Lab Sci Climat and Environm, F-91198 Gif Sur Yvette (France); Nycander, J. [Stockholm Univ, Dept Meteorol, S-10691 Stockholm (Sweden); Lampitt, R.S. [Natl Oceanog Ctr, Southampton SO14 3ZH, Hants (United Kingdom)

    2008-07-01

    Residual flow, baro-tropic tides and internal (baro-clinic) tides interact in a number of ways with kilometer-scale sea floor topography such as abyssal hills and sea mounts. Because of their likely impact on vertical mixing such interactions are potentially important for ocean circulation and the mechanisms and the geometry of these interactions are a matter of ongoing studies. In addition, very little is known about how these interactions are reflected in the sedimentary record. This multi-year study investigates if flow/topography interactions are reflected in distributional patterns of the natural short-lived (half-life: 24.1 d) particulate-matter tracer {sup 234}Th relative to its conservative (non-particle-reactive) and very long-lived parent nuclide {sup 238}U. The sampling sites were downstream of, or surrounded by, fields of short sea mounts and, therefore, very likely to be influenced by nearby flow/topography interactions. At the sampling sites between about 200 and 1000 m above the sea floor recurrent 'fossil' disequilibria were detected. 'Fossil' disequilibria are defined by clearly detectable {sup 234}Th/{sup 238}U disequilibria (total {sup 234}Th radioactivity {<=}{sup 238}U radioactivity, indicating a history of intense particulate {sup 234}Th scavenging and particulate-matter settling from the sampled parcel of water) and conspicuously low particle-associated {sup 234}Th activities. 'Fossil' disequilibria were centered at levels in the water column that correspond to the average height of the short sea mounts near the sampling sites. This suggests the 'fossil' disequilibria are formed on the sea mount slopes. Moreover, the magnitude of the 'fossil' disequilibria suggests that the slopes of the short sea mounts in the study region are characterized by particularly vigorous fluid dynamics. Since 'fossil' disequilibria already occurred at {approx} O (1-10 km) away from the sea mount slopes it

  6. Estimation of dose delivered to accelerator devices from stripping of 18.5 MeV/n 238U ions using the FLUKA code

    Science.gov (United States)

    Oranj, Leila Mokhtari; Lee, Hee-Seock; Leitner, Mario Santana

    2017-12-01

    In Korea, a heavy ion accelerator facility (RAON) has been designed for production of rare isotopes. The 90° bending section of this accelerator includes a 1.3- μm-carbon stripper followed by two dipole magnets and other devices. An incident beam is 18.5 MeV/n 238U33+,34+ ions passing through the carbon stripper at the beginning of the section. The two dipoles are tuned to transport 238U ions with specific charge states of 77+, 78+, 79+, 80+ and 81+. Then other ions will be deflected at the bends and cause beam losses. These beam losses are a concern to the devices of transport/beam line. The absorbed dose in devices and prompt dose in the tunnel were calculated using the FLUKA code in order to estimate radiation damage of such devices located at the 90° bending section and for the radiation protection. A novel method to transport multi-charged 238U ions beam was applied in the FLUKA code by using charge distribution of 238U ions after the stripper obtained from LISE++ code. The calculated results showed that the absorbed dose in the devices is influenced by the geometrical arrangement. The maximum dose was observed at the coils of first, second, fourth and fifth quadruples placed after first dipole magnet. The integrated doses for 30 years of operation with 9.5 p μA 238U ions were about 2 MGy for those quadrupoles. In conclusion, the protection of devices particularly, quadruples would be necessary to reduce the damage to devices. Moreover, results showed that the prompt radiation penetrated within the first 60 - 120 cm of concrete.

  7. Determination of extremely low (236)U/(238)U isotope ratios in environmental samples by sector-field inductively coupled plasma mass spectrometry using high-efficiency sample introduction.

    Science.gov (United States)

    Boulyga, Sergei F; Heumann, Klaus G

    2006-01-01

    A method by inductively coupled plasma mass spectrometry (ICP-MS) was developed which allows the measurement of (236)U at concentration ranges down to 3 x 10(-14)g g(-1) and extremely low (236)U/(238)U isotope ratios in soil samples of 10(-7). By using the high-efficiency solution introduction system APEX in connection with a sector-field ICP-MS a sensitivity of more than 5,000 counts fg(-1) uranium was achieved. The use of an aerosol desolvating unit reduced the formation rate of uranium hydride ions UH(+)/U(+) down to a level of 10(-6). An abundance sensitivity of 3 x 10(-7) was observed for (236)U/(238)U isotope ratio measurements at mass resolution 4000. The detection limit for (236)U and the lowest detectable (236)U/(238)U isotope ratio were improved by more than two orders of magnitude compared with corresponding values by alpha spectrometry. Determination of uranium in soil samples collected in the vicinity of Chernobyl nuclear power plant (NPP) resulted in that the (236)U/(238)U isotope ratio is a much more sensitive and accurate marker for environmental contamination by spent uranium in comparison to the (235)U/(238)U isotope ratio. The ICP-MS technique allowed for the first time detection of irradiated uranium in soil samples even at distances more than 200 km to the north of Chernobyl NPP (Mogilev region). The concentration of (236)U in the upper 0-10 cm soil layers varied from 2 x 10(-9)g g(-1) within radioactive spots close to the Chernobyl NPP to 3 x 10(-13)g g(-1) on a sampling site located by >200 km from Chernobyl.

  8. Associations of TNF-α -238 A/G and IL-10 -1082 G/A Genetic Polymorphisms With the Risk of NONFH in the Chinese Population.

    Science.gov (United States)

    Wei, Biao-Fang; Feng, Zhi; Wei, Wei; Chen, Xiao

    2017-12-01

    The study aims to explore the roles of common polymorphisms of Tumor Necrosis Factor-α (TNF-α) (-238 A/G and -308 A/G) and IL-10 (-819 T/C and -1082 G/A) genes in the risk of non-traumatic osteonecrosis of the femoral head (NONFH). One hundred and forty-seven NONFH patients and 135 healthy individuals were selected as the case and control groups. qRT-PCR and Western blotting techniques detected mRNA as well as protein expressions of TNF-α and IL-10 of each genotype in both the case and control groups. The GA genotype and the A allele of TNF-α -238 A/G were higher in the case group than in the control group. Compared with the control group, AA, GA, and AG + AA genotypes as well as the A allele of IL-10-1082 G/A were all lower in the case group. In the case groups increased levels of TNF-α as well as decreased levels of IL-10 expression when compared with the control group. TNF-α expression of TNF-α-238 GA genotype was significantly higher than that in patients with GG genotype, while the IL-10 expression of GA and AA genotypes of IL-10-1082 was significantly lower than in that of patients with the GG genotype. TNF-α protein expression in the GA genotype was significantly higher than in the GG genotype. In relation to TNF-α -238, TNF-α protein expression of GA and AA genotypes had significantly reduced more so than the GG genotype in IL-10-1082. TNF-α-238 A/G and IL-10-1082 G/A may be involved as risk factors of NONFH. J. Cell. Biochem. 118: 4872-4880, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Neutron capture cross section measurements of $^{238}$U, $^{241}$Am and $^{243}$Am at n_TOF

    CERN Multimedia

    Koehler, P E; Plag, R

    The increase of the world energy demand and the need of low carbon energy sources have triggered the renaissance and/or enhancement of nuclear energy in many countries. Fundamental nuclear physics can contribute in a practical way to the sustainability and safety of the nuclear energy production and the management of the nuclear waste. There exists a series of recent studies which address the most relevant isotopes, decay data, nuclear reaction channels and energy ranges which have to be investigated in more detail for improving the design of different advanced nuclear systems [1] and nuclear fuel cycles [2]. In this proposal, we aim at the measurement of the neutron capture cross sections of $^{238}$U, $^{241}$Am and $^{243}$Am. All three isotopes are listed in the NEA High Priority Request List [37], are recommended for measurements [1] and play an important role in the nuclear energy production and fuel cycle scenarios. The measurements will provide as well valuable nuclear structure data necessary for the...

  10. Alpha and conversion electron spectroscopy of 238,239Pu and 241Am and alpha-conversion electron coincidence measurements

    Science.gov (United States)

    Dion, Michael P.; Miller, Brian W.; Warren, Glen A.

    2016-09-01

    A technique to determine the isotopic constituents of a mixed actinide sample has been proposed by a coincident alpha-conversion electron measurement. This presents a unique signature to allow the unfolding of isotopes that possess overlapping alpha particle energy and reduce backgrounds of an unseparated sample. The work presented here are results of conversion electron spectroscopy of 241Am, 238Pu and 239Pu using a dual-stage peltier-cooled 25 mm2 silicon drift detector and alpha spectroscopy with a passivated ion implanted planar silicon detector. The conversion electron spectra were evaluated from 20-55 keV based on fits to the dominant conversion electron emissions, which allowed the relative conversion electron emission intensities to be determined. These measurements provide crucial singles spectral information and calibration to aid in the coincident measurement approach. Furthermore, an alpha-conversion electron spectrometer was assembled using the silicon based detectors described and results of a coincident spectrum analysis is reported for 241Am.

  11. Analysis of radon, uranium 238 and thorium 232 in potable waters: Dose to adult members of the Moroccan urban population

    Energy Technology Data Exchange (ETDEWEB)

    Misdaq, M.A. [Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, BP 2390, University Cadi Ayyad, Marrakech (Morocco)], E-mail: misdaq@ucam.ac.ma; Ouabi, H. [Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, BP 2390, University Cadi Ayyad, Marrakech (Morocco); Merzouki, A. [Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, BP 2390, University Cadi Ayyad, Marrakech (Morocco); Remote Sensing and Geomatics of the Environmental Laboratory, Ottawa-Carleton Geoscience Centre, Marion Hall, 140 Louis Pasteur, Ottawa, ON, KIN6N5 (Canada)

    2007-10-15

    Uranium ({sup 238}U) and thorium ({sup 232}Th) concentrations as well as radon ({sup 222}Rn) and thoron ({sup 220}Rn) alpha-activities per unit volume have been measured inside various potable water samples collected from nineteen cities in Morocco by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). Measured radon alpha-activities ranged from (0.37 {+-} 0.02) Bq l{sup -1} to (13.6 {+-} 1.10) Bq l{sup -1} for the potable water samples studied. Alpha-activities due to radon from the ingestion of the studied potable water samples were determined in different compartments of the gastrointestinal system by using the ICRP compartmental model for radon. Annual committed equivalent doses due to radon were evaluated in the gastrointestinal compartments from the ingestion of the potable water samples studied. The influence of the target tissue mass, radon intake and alpha-activity integral due to radon on the annual committed equivalent doses in the gastrointestinal compartments was investigated.

  12. Nuclear orientation in the reaction S34+U238 and synthesis of the new isotope Hs268

    Science.gov (United States)

    Nishio, K.; Hofmann, S.; Heßberger, F. P.; Ackermann, D.; Antalic, S.; Aritomo, Y.; Comas, V. F.; Düllmann, Ch. E.; Gorshkov, A.; Graeger, R.; Hagino, K.; Heinz, S.; Heredia, J. A.; Hirose, K.; Ikezoe, H.; Khuyagbaatar, J.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R.; Mitsuoka, S.; Nagame, Y.; Nishinaka, I.; Ohtsuki, T.; Popeko, A. G.; Saro, S.; Schädel, M.; Türler, A.; Watanabe, Y.; Yakushev, A.; Yeremin, A. V.

    2010-08-01

    The synthesis of isotopes of the element hassium was studied using the reaction S34+U238→Hs272*. At a kinetic energy of 163.0 MeV in the center-of-mass system we observed one α-decay chain starting at the isotope Hs267. The cross section was 1.8-1.5+4.2 pb. At 152.0 MeV one decay of the new isotope Hs268 was observed. It decays with a half-life of 0.38-0.17+1.8 s by 9479±16 keV α-particle emission. Spontaneous fission of the daughter nucleus Sg264 was confirmed. The measured cross section was 0.54-0.45+1.3 pb. In-beam measurements of fission-fragment mass distributions were performed to obtain information on the fusion probability at various orientations of the deformed target nucleus. The distributions changed from symmetry to asymmetry when the beam energy was changed from above-barrier to sub-barrier values, indicating orientation effects on fusion and/or quasifission. It was found that the distribution of symmetric mass fragments originates not only from fusion-fission, but has a strong component from quasifission. The result was supported by a calculation based on a dynamical description using the Langevin equation, in which the mass distributions for fusion-fission and quasifission fragments were separately determined.

  13. On monitoring anthropogenic airborne uranium concentrations and (235)U/(238)U isotopic ratio by Lichen - bio-indicator technique.

    Science.gov (United States)

    Golubev, A V; Golubeva, V N; Krylov, N G; Kuznetsova, V F; Mavrin, S V; Aleinikov, A Yu; Hoppes, W G; Surano, K A

    2005-01-01

    Lichens are widely used to assess the atmospheric pollution by heavy metals and radionuclides. However, few studies are available in publications on using lichens to qualitatively assess the atmospheric pollution levels. The paper presents research results applying epiphytic lichens as bio-monitors of quantitative atmospheric contamination with uranium. The observations were conducted during 2.5 years in the natural environment. Two experimental sites were used: one in the vicinity of a uranium contamination source, the other one - at a sufficient distance away to represent the background conditions. Air and lichens were sampled at both sites monthly. Epiphytic lichens Hypogimnia physodes were used as bio-indicators. Lichen samples were taken from various trees at about 1.5m from the ground. Air was sampled with filters at sampling stations. The uranium content in lichen and air samples as well as isotopic mass ratios (235)U/(238)U were measured by mass-spectrometer technique after uranium pre-extraction. Measured content of uranium were 1.45 mgkg(-1) in lichen at 2.09 E-04 microgm(-3) in air and 0.106 mgkg(-1) in lichen at 1.13 E-05 microgm(-3) in air. The relationship of the uranium content in atmosphere and that in lichens was determined, C(AIR)=exp(1.1 x C(LICHEN)-12). The possibility of separate identification of natural and man-made uranium in lichens was demonstrated in principle.

  14. Mass distribution and mass-resolved angular distribution in the 16O+238U reaction at sub-barrier energy

    Science.gov (United States)

    Nag, T. N.; Tripathi, R.; Sodaye, S.; Sudarshan, K.; Ramachandran, K.; Nayak, B. K.; Pujari, P. K.

    2017-10-01

    Background: The angular distribution of fission fragments or products is a sensitive probe to investigate non-compound-nucleus (NCN) fission. However, the gross angular distribution cannot distinguish between different NCN fission processes. Both preequilibrium fission and quasifission contribute to NCN fission and would both result in deviations from the statistical saddle point model (SSPM). Mass-resolved angular distributions of the fission product offers the possibility to distinguish between the two mechanisms [Sodaye et al., Phys. Rev. C 95, 014612 (2017), 10.1103/PhysRevC.95.014612; Tripathi et al., Phys. Rev. C 88, 024603 (2013), 10.1103/PhysRevC.88.024603; Vorkapic and Ivanisevic, Phys. Rev. C 55, 2711 (1997), 10.1103/PhysRevC.55.2711]. Purpose: Mass and mass-resolved angular distributions of fission products have been measured in the 16O+238U reaction at Elab=85.3 MeV to investigate the dominant NCN fission mechanism at sub-barrier energy. Method: Mass and mass-resolved angular distributions were measured by recoil catcher technique followed by offline γ-ray spectrometry. Results: The mass distribution was observed to be predominantly asymmetric. The angular anisotropy of the fission products was observed to be independent of their mass. Conclusions: The mass independence of the angular anisotropy suggested quasifission to be the dominant NCN fission process. This was further confirmed from the underestimation of angular anisotropy by theoretical calculations even after including the contribution from preequilibrium fission.

  15. Fission-fragment properties in 238U(n ,f ) between 1 and 30 MeV

    Science.gov (United States)

    Duke, D. L.; Tovesson, F.; Laptev, A. B.; Mosby, S.; Hambsch, F.-J.; Bryś, T.; Vidali, M.

    2016-11-01

    The fragment mass and kinetic energy in neutron-induced fission of 238U has been measured for incident energies from 1 to 30 MeV at the Los Alamos Neutron Science Center. The change in mass distributions over this energy range were studied, and the transition from highly asymmetric to more symmetric mass distributions is observed. A decrease in average total kinetic energy (TKE ¯) with increasing excitation energy is observed, consistent with previous experimental work. Additional structure at multichance fission thresholds is present in the TKE ¯ data. The correlations between fragment masses and total kinetic energy and how that changes with excitation energy of the fissioning compound nucleus were also measured. The fission mass yields and average total kinetic energy are important for fission-based technologies such as nuclear reactors to understand nuclear waste generation and energy output when developing new and advanced concepts. The correlations between fragment mass and kinetic energy are needed both as input for theoretical calculations of the deexcitation process in fission fragments by prompt radiation emission and for validating advanced theoretical fission models describing the formation of the primordial fragments.

  16. Gamma-Ray Emission Spectra as a Constraint on Calculations of 234 , 236 , 238U Neutron-Capture Cross Sections

    Science.gov (United States)

    Ullmann, J. L.; Krticka, M.; Kawano, T.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Haight, R. C.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Rundberg, R. S.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Wu, C. Y.; Chyzh, A.

    2015-10-01

    Calculations of the neutron-capture cross section at low neutron energies (10 eV through 100's of keV) are very sensitive to the nuclear level density and radiative strength function. These quantities are often poorly known, especially for radioactive targets, and actual measurements of the capture cross section are usually required. An additional constraint on the calculation of the capture cross section is provided by measurements of the cascade gamma spectrum following neutron capture. Recent measurements of 234 , 236 , 238U(n, γ) emission spectra made using the DANCE 4 π BaF2 array at the Los Alamos Neutron Science Center will be presented. Calculations of gamma-ray spectra made using the DICEBOX code and of the capture cross section made using the CoH3 code will also be presented. These techniques may be also useful for calculations of more unstable nuclides. This work was performed with the support of the U.S. Department of Energy, National Nuclear Security Administration by Los Alamos National Security, LLC (Contract DE-AC52-06NA25396) and Lawrence Livermore National Security, LLC (Contract DE-AC52-07NA2734).

  17. Gender differences in adolescent coping behaviors and suicidal ideation: findings from a sample of 73,238 adolescents.

    Science.gov (United States)

    Kim, Sun Mi; Han, Doug Hyun; Trksak, George H; Lee, Young Sik

    2014-01-01

    Suicide among adolescents is an emerging global public health problem as well as a socioeconomic problem. Stress-coping strategies have been shown to be associated with suicidal ideation. We examined coping behaviors related to suicidal ideation and gender differences in adolescents using the data from the 2010 Korea Youth Risk Behavior Survey (ages 12-19 years; N = 73,238). Logistic regression analysis was used to evaluate associations between suicidal ideation and specific coping behaviors while controlling for potentially confounding variables. In both male and female groups, the coping behavior "drinking alcoholic beverages" and "smoking cigarettes" were positively associated with suicidal ideation. "Watching TV," "playing online/mobile games," and "sleeping" were negatively associated with suicidal ideation in both groups. In males, "engaging in sports" was negatively related to suicidal ideation. In females, "venting by talking to others" and "eating" were negatively related to suicidal ideation. The results indicate that there are gender differences in the effects of coping behaviors on adolescent suicidal ideation, and that developing adaptive coping strategies may function to reduce suicidality. Future studies are needed to examine whether improving coping skills can reduce suicidal ideation in a gender-specific manner.

  18. Activity concentrations of {sup 238}U and {sup 226}Ra in scales formed on pipes of industrial boilers in the state of Pernambuco, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Poggi, Claudia M.B.; Farias, Emerson E.G. de, E-mail: claudiapoggi04@gmail.com, E-mail: emersonemiliano@yahoo.com.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Franca, Elvis J.; Hazin, Clovis A., E-mail: chazin@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Gazineu, Maria H.P., E-mail: helena@unicap.br [Universidade Catolica de Pernambuco (UNICAP), Recife, PE (Brazil). Centro de Ciencias e Tecnologia

    2015-07-01

    The procedures employed in the industry can generate significant amounts of solid, liquid and gaseous wastes that usually contain toxic or materials of difficulty degradation. One of the facts that contribute to the formation of such wastes is the generation of steam used in operating processes and industry segments. Currently, steam supplied by boilers is the most economical and practical mode of heat transfer in industrial processes. Due to the high temperature of water used in these processes, compounds which were previously soluble become insoluble, generating residues called scales. This material, which contains stable ions, can also present naturally occurring radionuclides such as {sup 238}U and {sup 226}Ra, which concentrate over time in piping and equipment surfaces. If not disposed correctly, this material also can contaminate the environment. The main origin of these radionuclides is the use of groundwater in industrial processes. Thus, in regions of naturally enriched in radionuclides such as the Region of Pernambuco, including the municipalities of Paulista and Goiana, there is a greater possibility of radioactive scale formation. Therefore, this study aimed to determine the activity concentrations of {sup 238}U and {sup 226}Ra present in the solid wastes generated by industries situated in Paulista and Goiana, in order to assess radionuclide disequilibrium. For the sake of comparison, scale samples collected from industries located in the municipality of Caruaru, far from the previous municipalities, were also analyzed. The determination of the activity concentrations for {sup 238}U and {sup 226}Ra was performed by High Resolution Gamma-Ray Spectrometry. Samples were collected, prepared, packed in plastic containers and set aside for a minimum time of 21 days, for the secular equilibrium to occur between {sup 226}Ra and its short lived descendants. The counting time was 80,000 seconds. Gamma energies used for determination of activity concentrations

  19. Bioaccumulation of polonium ({sup 210}Po) and uranium ({sup 234}U, {sup 238}U) in plants around phosphogypsum waste heap in Wislinka (northern Poland)

    Energy Technology Data Exchange (ETDEWEB)

    Borylo, A.; Skwarzec, B. [Gdansk Univ. (Poland). Faculty of Chemistry

    2011-07-01

    In the study the activities of polonium {sup 210}Po and uranium {sup 234}U, {sup 238}U in plants, collected near phosphogypsum waste heap in Wis'linka (northern Poland), were determined by using the alpha spectrometry. The obtained results revealed that the concentrations of {sup 210}Po, {sup 234}U, and {sup 238}U in the analyzed plants were differentiated. In the analyzed flora organisms the highest amounts of polonium and uranium were found in ruderal plant samples as well as willow samples (Salix viminalis) from protection zone of phosphogypsum waste heap. The concentrations of {sup 210}Po, {sup 234}U and {sup 238}U in the analyzed plants were higher in roots than in green parts of plants. The higher concentrations of {sup 210}Po and {sup 238}U radionuclides were estimated for hydrophyte (common sedge Carex nigra Reichard), the favourite habitat of which is particularly wet meadow and for plants collected in the vicinity of phosphogypsum waste heap. The major source of polonium and uranium in analyzed plants is root system. The values of {sup 234}U/ {sup 238}U activity ratio in all analyzed plants are closed to one, what indicated that source of uranium in analyzed plants is phosphogypsum. The highest uranium and polonium concentrations were characterized for plants, which are covered with tomentose. The comparability polonium and uranium contents were confirmed in edible plants, but higher accumulation was determined in ripe species than immature species of vegetables. The higher polonium and uranium concentrations were noticed in green parts of plant, the lower in roots. Polonium concentration in cultivated plants samples was not species diverse. Therefore, the significant source of polonium and uranium in analyzed plants is wet and dry atmospheric falls gathering the soil and air dust from phosphogypsum waste dump. The maximum {sup 210}Po and {sup 238}U radionuclides concentrations were found in green parts of red beet (Beta vulgaris esculenta), the

  20. 233 - 238 Musa Kifi

    African Journals Online (AJOL)

    User

    2015-12-02

    Dec 2, 2015 ... treated using motor and pestle and winnowed on a tray by blowing air through to remove the chaff .... The value of hydrogen cyanide recorded in this study for the raw seed of (0.17mg/100g) was found to be lower when compared to the hydrogen cyanide content of certain common legume raw seeds such ...

  1. 233 - 238 Musa Kifi

    African Journals Online (AJOL)

    User

    2015-12-02

    Dec 2, 2015 ... The seed meal was evaluated for saponin, tannin, cyanide, oxalate, phytate and phenols. The result showed that heat processing significantly (P < 0.05) affected the ANFs in the seed meal. Highest value of saponin (0.07mg/100g) was recorded in T1, while zero level of saponin was recorded in T4.

  2. Influence of multi chance fission on fragment angular anisotropy in the {sup 232}Th(n,f) and {sup 238}U(n,f) reactions at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhov, I.V. [V.G. Khlopin Radium Institute, 2nd Murinski Prospect 28, 194021 Saint-Petersburg (Russian Federation); Onegin, M.S. [Petersburg Nuclear Physics Institute of Russian Academy of Science, 188350 Gatchina, Leningrad district (Russian Federation); Tutin, G.A. [V.G. Khlopin Radium Institute, 2nd Murinski Prospect 28, 194021 Saint-Petersburg (Russian Federation); Blomgren, J. [Department of Neutron Research, Uppsala University, Box 525, S-75120 Uppsala (Sweden); Olsson, N. [Department of Neutron Research, Uppsala University, Box 525, S-75120 Uppsala (Sweden); Swedish Defence Research Agency (FOI), S-172 90 Stockholm (Sweden); Prokofiev, A.V. [V.G. Khlopin Radium Institute, 2nd Murinski Prospect 28, 194021 Saint-Petersburg (Russian Federation) and Svedberg Laboratory, Uppsala University, Box 533, S-75121 Uppsala (Sweden)]. E-mail: alexander.prokofiev@tsl.uu.se; Renberg, P.-U. [The Svedberg Laboratory, Uppsala University, Box 533, S-75121 Uppsala (Sweden)

    2005-10-03

    Fission fragment angular distributions have been measured for the {sup 232}Th(n,f) and {sup 238}U(n,f) reactions in the neutron energy range 20-100 MeV. The fragment angular anisotropy for {sup 232}Th was found to be systematically larger than that for {sup 238}U. The obtained results have been analyzed in the framework of the statistical saddle-point model combined with pre-equilibrium and Hauser-Feshbach calculations of partial fission cross sections. The calculations have revealed that fission following multiple neutron emission takes place in both reactions, resulting in a considerable contribution of high chances to the total fission fragment angular anisotropy. This gives grounds to expect that the observed difference is mainly due to nuclei fissioning at the end of the neutron evaporation chain.

  3. Association between -238 but not -308 polymorphism of Tumor necrosis factor alpha (TNF-alphav and unexplained recurrent spontaneous abortion (URSA in Chinese population

    Directory of Open Access Journals (Sweden)

    Zhou Sirui

    2010-09-01

    Full Text Available Abstract Objectives TNF-alpha is a critical cytokine produced by Th1 cells while altered T helper 1 (Th1-Th2 balance is found crucial for a successful pregnancy. Study Design A cohort of 132 Southern Chinese Han RSA patients and 152 controls constituted the subjects of this study. Two functional polymorphisms -308 and -238 of TNF-alpha were studied by association analysis. Results lack of association was found in TNF-alpha -308 SNP yet a significant difference was discovered in -238 polymorphism. Conclusion This study suggested that TNF-alpha may be a risk factor in Chinese RSA patients. However the ethnic differences may also contribute to the results.

  4. Towards the high-accuracy determination of the 238U fission cross section at the threshold region at CERN - n_TOF

    Science.gov (United States)

    Diakaki, M.; Audouin, L.; Berthoumieux, E.; Calviani, M.; Colonna, N.; Dupont, E.; Duran, I.; Gunsing, F.; Leal-Cidoncha, E.; Le Naour, C.; Leong, L. S.; Mastromarco, M.; Paradela, C.; Tarrio, D.; Tassan-Got, L.; Aerts, G.; Altstadt, S.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Badurek, G.; Barbagallo, M.; Baumann, P.; Becares, V.; Becvar, F.; Belloni, F.; Berthier, B.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calvino, F.; Cano-Ott, D.; Capote, R.; Carrapiço, C.; Cennini, P.; Cerutti, F.; Chiaveri, E.; Chin, M.; Cortes, G.; Cortes-Giraldo, M. A.; Cosentino, L.; Couture, A.; Cox, J.; David, S.; Dillmann, I.; Domingo-Pardo, C.; Dressler, R.; Dridi, W.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Finocchiaro, P.; Fraval, K.; Fujii, K.; Furman, W.; Ganesan, S.; Garcia, A. R.; Giubrone, G.; Gomez-Hornillos, M. B.; Goncalves, I. F.; Gonzalez-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Gurusamy, P.; Haight, R.; Heil, M.; Heinitz, S.; Igashira, M.; Isaev, S.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Kaeppeler, F.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Ketlerov, V.; Kivel, N.; Kokkoris, M.; Konovalov, V.; Krticka, M.; Kroll, J.; Lampoudis, C.; Langer, C.; Lederer, C.; Leeb, H.; Lo Meo, S.; Losito, R.; Lozano, M.; Manousos, A.; Marganiec, J.; Martinez, T.; Marrone, S.; Massimi, C.; Mastinu, P.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Mondelaers, W.; Moreau, C.; Mosconi, M.; Musumarra, A.; O'Brien, S.; Pancin, J.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perkowski, J.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, L.; Poch, A.; Pretel, C.; Praena, J.; Quesada, J.; Rauscher, T.; Reifarth, R.; Riego, A.; Roman, F.; Rudolf, G.; Rubbia, C.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tavora, L.; Terlizzi, R.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M. J.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Wallner, A.; Walter, S.; Ware, T.; Weigand, M.; Weiß, C.; Wiesher, M.; Wisshak, K.; Wright, T.; Zugec, P.

    2016-03-01

    The 238U fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The 238U fission cross section has been measured relative to the 235U fission cross section at CERN - n_TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards.

  5. Towards the high-accuracy determination of the 238U fission cross section at the threshold region at CERN – n_TOF

    Directory of Open Access Journals (Sweden)

    Diakaki M.

    2016-01-01

    Full Text Available The 238U fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The 238U fission cross section has been measured relative to the 235U fission cross section at CERN – n_TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards.

  6. Electromagnetic dissociation of sup 238 U in heavy-ion collisions at 120 MeV/A

    Energy Technology Data Exchange (ETDEWEB)

    Justice, M.L.

    1991-04-01

    This thesis describes a measurement of the heavy-ion induced electromagnetic dissociation of a 120 MeV/A {sup 238}U beam incident on five targets: {sup 9}Be, {sup 27}Al, {sup nat}Cu, {sup nat}Ag, and {sup nat}U. Electromagnetic dissociation at this beam energy is essentially a two step process involving the excitation of a giant resonance followed by particle decay. At 120 MeV/A there is predicted to be a significant contribution of the giant quadrupole resonance to the EMD cross sections. The specific exit channel which was looked at was projectile fission. The two fission fragments were detected in coincidence by an array of solid-state {Delta}E-E detectors, allowing the changes of the fragments to be determined to within {plus minus} .5 units. The events were sorted on the basis of the sums of the fragments' charges, acceptance corrections were applied, and total cross sections for the most peripheral events were determined. Electromagnetic fission at the beam energy of this experiment always leads to a true charge sum of 92. Due to the imperfect resolution of the detectors, charge sums of 91 and 93 were included in order to account for all of the electromagnetic fission events. The experimentally observed cross sections are due to nuclear interaction processes as well as electromagnetic processes. Under the conditions of this experiment, the cross sections for the beryllium target are almost entirely due to nuclear processes. The nuclear cross sections for the other four targets were determined by extrapolation from the beryllium data using a geometrical scaling model. After subtraction of the nuclear cross sections, the resulting electromagnetic cross sections are compared to theoretical calculations based on the equivalent photon approximation. Systematic uncertainties are discussed and suggestions for improving the experiment are given.

  7. Electromagnetic dissociation of 238U in heavy-ion collisions at 120 MeV/A

    Energy Technology Data Exchange (ETDEWEB)

    Justice, Marvin Lealon [Univ. of California, Berkeley, CA (United States)

    1991-04-01

    This thesis describes a measurement of the heavy-ion induced electromagnetic dissociation of a 120 MeV/A 238U beam incident on five targets: 9Be, 27Al, natCu, natAg, and natU. Electromagnetic dissociation at this beam energy is essentially a two step process involving the excitation of a giant resonance followed by particle decay. At 120 MeV/A there is predicted to be a significant contribution of the giant quadrupole resonance to the EMD cross sections. The specific exit channel which was looked at was projectile fission. The two fission fragments were detected in coincidence by an array of solid-state ΔE-E detectors, allowing the changes of the fragments to be determined to within ± .5 units. The events were sorted on the basis of the sums of the fragments` charges, acceptance corrections were applied, and total cross sections for the most peripheral events were determined. Electromagnetic fission at the beam energy of this experiment always leads to a true charge sum of 92. Due to the imperfect resolution of the detectors, charge sums of 91 and 93 were included in order to account for all of the electromagnetic fission events. The experimentally observed cross sections are due to nuclear interaction processes as well as electromagnetic processes. Under the conditions of this experiment, the cross sections for the beryllium target are almost entirely due to nuclear processes. The nuclear cross sections for the other four targets were determined by extrapolation from the beryllium data using a geometrical scaling model. After subtraction of the nuclear cross sections, the resulting electromagnetic cross sections are compared to theoretical calculations based on the equivalent photon approximation. Systematic uncertainties are discussed and suggestions for improving the experiment are given.

  8. Delayed Fission Gamma-ray Characteristics of Th-232 U-233 U-235 U-238 and Pu-239

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Taylor [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Parma, Edward J. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-08-01

    Delayed fission gamma-rays play an important role in determining the time dependent ioniz- ing dose for experiments in the central irradiation cavity of the Annular Core Research Reactor (ACRR). Delayed gamma-rays are produced from both fission product decay and from acti- vation of materials in the core, such as cladding and support structures. Knowing both the delayed gamma-ray emission rate and the time-dependent gamma-ray energy spectrum is nec- essary in order to properly determine the dose contributions from delayed fission gamma-rays. This information is especially important when attempting to deconvolute the time-dependent neutron, prompt gamma-ray, and delayed gamma-ray contribution to the response of a diamond photo-conducting diode (PCD) or fission chamber in time frames of milliseconds to seconds following a reactor pulse. This work focused on investigating delayed gamma-ray character- istics produced from fission products from thermal, fast, and high energy fission of Th-232, U-233, U-235, U-238, and Pu-239. This work uses a modified version of CINDER2008, a transmutation code developed at Los Alamos National Laboratory, to model time and energy dependent photon characteristics due to fission. This modified code adds the capability to track photon-induced transmutations, photo-fission, and the subsequent radiation caused by fission products due to photo-fission. The data is compared against previous work done with SNL- modified CINDER2008 [ 1 ] and experimental data [ 2 , 3 ] and other published literature, includ- ing ENDF/B-VII.1 [ 4 ]. The ability to produce a high-fidelity (7,428 group) energy-dependent photon fluence at various times post-fission can improve the delayed photon characterization for radiation effects tests at research reactors, as well as other applications.

  9. Dynamics of 40,48Ca +238 U→ 278 , 286112* reactions across the Coulomb barrier using dynamical cluster decay model

    Science.gov (United States)

    Sandhu, Kirandeep; Kaur, Gurvinder; Sharma, Manoj K.

    2014-01-01

    The role of deformations and related orientations (optimum or compact) is investigated in reference to dynamics of 40,48Ca +238 U→ 278 , 286112* reactions using dynamical cluster decay model (DCM). The use of quadrupole and hexadecapole deformations in the decay of compound system suggest that the degree of compactness changes with addition of higher order deformations. The decay cross-sections are calculated in reference to the available data, including β2-static deformations within 'optimum' orientation approach. The comparative analysis of spherical, β2-static and dynamic alongwith β4-static deformations is investigated at comparable center of mass energy of 230 MeV for both nuclei. To address the specific role of optimized orientations in the decay of 112278* and 112286* nuclei, the calculations are done using equatorial compact and polar elongated orientations. Using hot equatorial collisions, symmetric fission is observed as the dominant decay mode across the barrier, which otherwise becomes asymmetric for cold elongated approach. The calculated cross-sections match nicely with experimental data using hot configuration but the same are overestimated for the use of cold (polar) orientation approach at deep sub-barrier region. This overestimation in the deep sub-barrier region may be associated with the quasi-fission decay channel. The contribution of QF in both 112278* and 112286* nuclei are predicted through the overestimated cross-sections being more for neutron-deficient 112278* nucleus, in agreement with experimental results. Larger barrier modification ΔVB is observed at sub-barrier energies for both isotopes of Z = 112 nucleus. Also the contribution of ΔVB at lower incident energies is relatively higher for cold elongated polar configuration as compared to hot compact equatorial configuration, causing overestimation of cross-section for the use of cold approach.

  10. Evaluation of the VDA 238-100 Tight Radius Bending Test using Digital Image Correlation Strain Measurement

    Science.gov (United States)

    Cheong, K.; Omer, K.; Butcher, C.; George, R.; Dykeman, J.

    2017-09-01

    The VDA238-100 standard for tight radius bending (v-bending) of sheet materials has received widespread acceptance with automotive suppliers and material producers to characterize local formability. However, the test fixture and tooling in the v-bend test standard is not amenable to direct strain measurement and the operator cannot terminate the test at the onset of crack initiation as the outer bend surface is not visible. Consequently, fracture is identified using a load threshold and the bend angle estimated from an analytical formula based upon the punch displacement and tooling geometry. Bend angles are not directly transferable and must be interpreted relative to the sheet thickness and bend radius unlike a strain measurement. By obtaining an in-situ strain measurement on the surface using digital image correlation (DIC), the plane strain fracture limit can be accurately identified at the onset of cracking and remove ambiguity in translating the bend angles to practical forming operations and simulations. A novel inverted VDA test frame was developed to incorporate DIC strain measurement during the bend test and a variety of advanced high strength sheet materials were evaluated. It was observed that the VDA bend test creates a homogeneous strain state of plane strain across the width of the sample along with a proportional strain path to fracture without necking that is ideal for fracture characterization. A correlation is developed to relate the bend angle with the major strain for the materials considered and accounts for the sheet thickness and bend radius. A comparison of the bend angle obtained using the formula in the VDA standard based on the punch displacement was in very good agreement with manual measurements and an algorithm to measure the bend angle using DIC analysis was developed.

  11. The first 238 amino acids of the human lamin B receptor are targeted to the nuclear envelope in plants.

    Science.gov (United States)

    Irons, Sarah L; Evans, David E; Brandizzi, Federica

    2003-03-01

    In plants, the nuclear envelope (NE) is one of the least characterized cellular structures. In particular, little is known about its dynamics during the cell cycle. This is due to the absence of specific markers for in vivo studies. To generate such an in vivo marker, the suitability of the human lamin B receptor (LBR) was tested. When the first 238 amino acids of the LBR, fused to the green fluorescent protein (GFP), were expressed in tobacco plants, fluorescence accumulated only at the NE of leaf epidermal cells. This was confirmed by electron microscopy. The protein was shown to be membrane-integral by phase separation. Distribution of fluorescence was compared with two ER markers, GFP-calnexin and GFP-HDEL. While co-localization of all three markers was noted at the NE, only LBR-GFP was specific to the NE, while the other two also showed fluorescence of the cortical ER. These results suggest that common targeting mechanisms to those in animals and fungi exist in plants to direct and locate proteins to the NE. This chimaeric construct is the first available fluorescent integral membrane protein marker to be targeted exclusively to the plant NE and it provides a novel opportunity to investigate the dynamics of this membrane system in vivo. With it, the cell cycle was followed in tobacco BY-2 cells stably expressing the fusion protein. The interphase labelling of the NE altered in metaphase into an ER-like meshwork, suggesting the dispersal of the NE to ER as in animal cells. Finally, the meshwork of fluorescent membranes was lost and new fluorescent NE formed around the daughter nuclei.

  12. Influence of soil texture on the distribution and availability of {sup 238}U, {sup 230}Th, and {sup 226}Ra in soils

    Energy Technology Data Exchange (ETDEWEB)

    Blanco Rodriguez, P. [Departamento de Fisica, Facultad de Ciencias, Universidad de Extremadura, Avd. Elvas s/n, 06071 Badajoz (Spain); Vera Tome, F. [Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Extremadura, Avd. Elvas s/n, 06071 Badajoz (Spain)], E-mail: fvt@unex.es; Lozano, J.C. [Laboratorio de Radiactividad Ambiental, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca (Spain); Perez-Fernandez, M.A. [Area de Ecologia, Universidad Pablo Olavide, Carretera de Utrera km. 1, 41013 Sevilla (Spain)

    2008-08-15

    The influence of soil texture on the distribution and availability of {sup 238}U, {sup 230}Th, and {sup 226}Ra in soils was studied in soil samples collected at a rehabilitated uranium mine located in the Extremadura region in south-west Spain. The activity concentration (Bq kg{sup -1}) in the soils ranged from 60 to 750 for {sup 238}U, from 60 to 260 for {sup 230}Th, and from 70 to 330 for {sup 226}Ra. The radionuclide distribution was determined in three soil fractions: coarse sand (0.5-2 mm), medium-fine sand (0.067-0.5 mm), and silt and clay (<0.067 mm). The relative mobility of the natural radionuclides in the different fractions was studied by comparison of the activity ratios between radionuclides belonging to the same radioactive series. The lability of these radionuclides in each fraction was also studied through selective extraction from the soils using a one-step sequential extraction scheme. Significant correlations were found for {sup 238}U, {sup 230}Th, and {sup 226}Ra between the activity concentration per fraction and the total activity concentration in the bulk soil. Thus, from the determination of the activity concentration in the bulk soil, one could estimate the activity concentration in each fraction. Correlations were also found for {sup 238}U and {sup 226}Ra between the labile activity concentration in each fraction and the total activity concentration in bulk soil. Assuming that there is some particle-size fraction that predominates in the process of soil-to-plant transfer, the parameters obtained in this study should be used as correction factors for the transfer factors determined from the bulk soil in previous studies.

  13. Measurement of the 238U Radiative Capture Cross Section with C6D6 at the CERN n_TOF Facility

    CERN Document Server

    Mingrone, F; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Bečvář, F; Belloni, F; Berthoumieux, E; Billowes, J; Bosnar, D; Brugger, M; Calviani, M; Calviño, F; Cano-Ott, D; Carrapiço, C; Cerutti, F; Chiaveri, E; Chin, M; Colonna, N; Cortés, G; Cortés-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; García, A R; Giubrone, G; Gonçalves, I F; González-Romero, E; Griesmayer, E; Guerrero, C; Gunsing, F; Hernández-Prieto, A; Jenkins, D G; Jericha, E; Kadi, Y; Käppeler, F; Karadimos, D; Kivel, N; Koehler, P; Kokkoris, M; Krtička, M; Kroll, J; Lampoudis, C; Langer, C; Leal-Cidoncha, E; Lederer, C; Leeb, H; Leong, L S; Losito, R; Mallick, A; Manousos, A; Marganiec, J; Martínez, T; Mastinu, P F; Mastromarco, M; Mendoza, E; Mengoni, A; Milazzo, P M; Mirea, M; Mondalaers, W; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Robles, M S; Rubbia, C; Sabaté-Gilarte, M; Sarmento, R; Saxena, A; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiß, C; Wright, T; Žugec, P

    2014-01-01

    We present the preliminary results of the U-238(n,gamma) reaction cross section measurement, performed on April 2012 at the CERN n\\_TOF facility using C6D6 scintillation detectors over an energy range from thermal to 1 MeV. The goal of this measurement, which is part of a larger proposal, is to reach an uncertainty of 2\\% in the cross section. The experimental set-up and the methods used to obtain this result are described.

  14. In vitro effects of Laccaria bicolor S238 N and Pseudomonas fluorescens strain BBc6 on rooting of de-rooted shoot hypocotyls of Norway spruce.

    Science.gov (United States)

    Karabaghli, C.; Frey-Klett, P.; Sotta, B.; Bonnet, M.; Le Tacon, F.

    1998-02-01

    The ectomycorrhizal fungus Laccaria bicolor S238 N and the bacterium Pseudomonas fluorescens BBc6 were used separately and in combination to induce in vitro rooting of de-rooted shoot hypocotyls of Norway spruce (Picea abies (L.) Karst.). When the culture medium was supplemented with tryptophan, a precursor of indole-3-acetic acid (IAA) synthesis, the presence of the ectomycorrhizal fungus increased the percentage of hypocotyls forming roots; furthermore, both the fungal and bacterial inoculations enhanced the number of roots formed per rooted hypocotyl. Similar results were obtained by adding exogenous IAA (5 and 10 &mgr;M) to the rooting medium. After the rooting phase, the fungal inoculation enhanced adventitious root elongation and branching as well as the aerial growth of the cuttings. Pseudomonas fluorescens BBc6 had no effect on these parameters. The production of IAA by pure cultures of L. bicolor S238 N and P. fluorescens BBc6 was estimated by immunochemical analysis using specific anti-IAA antibodies. Both L. bicolor S238 N and P. fluorescens BBc6 synthesized IAA in pure culture and synthesis was stimulated in the presence of tryptophan. Thus, the effect of the fungus in stimulating adventitious root formation and subsequent elongation and branching can be attributed, at least partially, to the synthesis of IAA by the fungus. The finding that P. fluorescens BBc6 had no effect on root elongation and branching although it produced IAA suggests that either IAA was not the only parameter involved in the stimulation of these processes by L. bicolor S238 N or the bacterium produced other compounds that counteracted the stimulatory effects of IAA on root elongation and branching.

  15. Natural Activities of 238U, 232Th and 40K in Manganese Ore

    OpenAIRE

    H. A. Abel-Ghany

    2010-01-01

    Problem statement: Manganese ore is widely used in much industries. Such as ore contain natural radioactive nuclides at various concentrations. If this ore contain high concentrations of natural radioactive nuclides, workers handling them might be exposed to significant levels of radiation. Therefore it is important to determine the radioactive nuclides in this ore. Approach: The natural radionuclides (238U, 232Th and 40K) contents of Manganese ore samples collected by Siani Manganese Company...

  16. Uranium 238U/235U isotope ratios as indicators of reduction: Results from an in situ biostimulation experiment at Rifle, Colorado, USA

    Energy Technology Data Exchange (ETDEWEB)

    Bopp IV, C.J.; Lundstrom, C.C.; Johnson, T.M.; Sanford, R.A.; Long, P.E.; Williams, K.H.

    2010-02-01

    The attenuation of groundwater contamination via chemical reaction is traditionally evaluated by monitoring contaminant concentration through time. However, this method can be confounded by common transport processes (e.g. dilution, sorption). Isotopic techniques bypass the limits of concentration methods, and so may provide improved accuracy in determining the extent of reaction. We apply measurements of {sup 238}U/{sup 235}U to a U bioremediation field experiment at the Rifle Integrated Field Research Challenge Site in Rifle, Colorado (USA). An array of monitoring and injection wells was installed on a 100 m{sup 2} plot where U(VI) contamination was present in the groundwater. Acetate-amended groundwater was injected along an up-gradient gallery to encourage the growth of dissimilatory metal reducing bacteria (e.g. Geobacter species). During amendment, U concentration dropped by an order of magnitude in the experiment plot. We measured {sup 238}U/{sup 235}U in samples from one monitoring well by MC-ICP-MS using a double isotope tracer method. A significant {approx}1.00{per_thousand} decrease in {sup 238}U/{sup 235}U occurred in the groundwater as U(VI) concentration decreased. The relationship between {sup 238}U/{sup 235}U and concentration corresponds approximately to a Rayleigh distillation curve with an effective fractionation factor ({alpha}) of 1.00046. We attribute the observed U isotope fractionation to a nuclear field shift effect during enzymatic reduction of U(VI){sub (aq)} to U(IV){sub (s)}.

  17. Charge-state distribution measurements of ^{238}U and ^{136}Xe at 11  MeV/nucleon using gas charge stripper

    Directory of Open Access Journals (Sweden)

    H. Kuboki

    2010-09-01

    Full Text Available The charge-state distributions and equilibrium charge states of uranium (^{238}U and xenon (^{136}Xe ions at 11  MeV/nucleon were determined using a gas charge stripper. A differential pumping system facilitated the increase of the nitrogen gas thickness up to 1.3  mg/cm^{2}, which is sufficient for the most probable charge state to attain equilibrium. The charge states of ^{238}U attain equilibrium at 56.0, 56.6, and 55.7 in N_{2}, Ar, and CO_{2} media with thicknesses of 125, 79, and 126  μg/cm^{2}, respectively, while those of ^{136}Xe attain equilibrium at 40.5, 40.1, and 40.3 in N_{2}, Ar, and CO_{2} media with thicknesses of 163, 95, and 139  μg/cm^{2}, respectively. The equilibrium charge states of ^{136}Xe are acceptable for acceleration by the subsequent cyclotron. The measured data of ^{238}U were used to devise an empirical formula for the prediction of the equilibrium charge state in gaseous media over the energy region of 0.01–60  MeV/nucleon. The equilibrium charge state of ^{136}Xe as predicted by the devised formula is in good agreement with the data.

  18. Uncertainty analysis on reactivity and discharged inventory for a pressurized water reactor fuel assembly due to {sup 235,238}U nuclear data uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Da Cruz, D. F.; Rochman, D.; Koning, A. J. [Nuclear Research and Consultancy Group NRG, Westerduinweg 3, 1755 ZG Petten (Netherlands)

    2012-07-01

    This paper discusses the uncertainty analysis on reactivity and inventory for a typical PWR fuel element as a result of uncertainties in {sup 235,238}U nuclear data. A typical Westinghouse 3-loop fuel assembly fuelled with UO{sub 2} fuel with 4.8% enrichment has been selected. The Total Monte-Carlo method has been applied using the deterministic transport code DRAGON. This code allows the generation of the few-groups nuclear data libraries by directly using data contained in the nuclear data evaluation files. The nuclear data used in this study is from the JEFF3.1 evaluation, and the nuclear data files for {sup 238}U and {sup 235}U (randomized for the generation of the various DRAGON libraries) are taken from the nuclear data library TENDL. The total uncertainty (obtained by randomizing all {sup 238}U and {sup 235}U nuclear data in the ENDF files) on the reactor parameters has been split into different components (different nuclear reaction channels). Results show that the TMC method in combination with a deterministic transport code constitutes a powerful tool for performing uncertainty and sensitivity analysis of reactor physics parameters. (authors)

  19. Association of G308A and G238A Polymorphisms of the TNF-α Gene with Risk of Coronary Heart Disease: Systematic Review and Meta-analysis.

    Science.gov (United States)

    Pulido-Gómez, Karely; Hernández-Díaz, Yazmín; Tovilla-Zárate, Carlos Alfonso; Juárez-Rojop, Isela Esther; González-Castro, Thelma Beatriz; López-Narváez, María Lilia; Alpuin-Reyes, Mariela

    2016-10-01

    It is widely acknowledged that coronary heart disease (CHD) has a genetic influence. One of the most promising candidate genes is tumor necrosis factor-alpha (TNF-α). Although there have been several positive studies associating the TNF-α gene and CHD, the evidence is not entirely consistent. The aim of the study was to evaluate the role of the TNF-α gene in CHD using combined evidence by generating a meta-analysis and a systematic review of all published data. Meta-analysis and systematic review were conducted using 27 articles of genetic association studies of the TNF-α gene variants (G308A and G238A) and CHD. To analyze the association we used allelic, additive, dominant and recessive models. Moreover, we conducted a subanalysis by populations using the same four models. TNF-α variant G308A showed a significant association with CHD but only when the analysis comprised the whole population. In addition, the variant G238A yielded the same outcome in the Asian population. Genetic polymorphisms at positions -308 and -238 in the promoter region of the TNF-α gene may be useful as predictive factors for CHD. Copyright © 2016 IMSS. Published by Elsevier Inc. All rights reserved.

  20. Uranium ((234)U, (235)U and (238)U) contamination of the environment surrounding phosphogypsum waste heap in Wiślinka (northern Poland).

    Science.gov (United States)

    Olszewski, Grzegorz; Boryło, Alicja; Skwarzec, Bogdan

    2015-08-01

    The aim of this work was to determine the uranium concentration ((234)U, (235)U and (238)U) and values of the activity ratio (234)U/(238)U in soil samples collected near phosphogypsum waste heap in Wiślinka (northern Poland). On the basis of the studies it was found that the values of the (234)U/(238)U activity ratio in the analyzed soils collected in the vicinity of phosphogypsum dump in Wiślinka are in most cases close to one and indicate the phosphogypsum origin of the analyzed nuclides. The obtained results of uranium concentrations are however much lower than in previous years before closing of the phosphogypsum stockpile. After this process and covering the phosphogypsum stockpile in Wiślinka with sewage sludge, phosphogypsum particles are successfully immobilized. In the light of the results the use of phosphate fertilizers seems to be a major problem. Prolonged and heavy rains can cause leaching accumulated uranium isotopes in the phosphogypsum stockpile, which will be washed into the Martwa Wisła and on the fields in the immediate vicinity of this storage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Standard test method for analysis of urine for uranium-235 and uranium-238 isotopes by inductively coupled plasma-mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the determination of the concentration of uranium-235 and uranium-238 in urine using Inductively Coupled Plasma-Mass Spectrometry. This test method can be used to support uranium facility bioassay programs. 1.2 This method detection limits for 235U and 238U are 6 ng/L. To meet the requirements of ANSI N13.30, the minimum detectable activity (MDA) of each radionuclide measured must be at least 0.1 pCi/L (0.0037 Bq/L). The MDA translates to 47 ng/L for 235U and 300 ng/L for 238U. Uranium– 234 cannot be determined at the MDA with this test method because of its low mass concentration level equivalent to 0.1 pCi/L. 1.3 The digestion and anion separation of urine may not be necessary when uranium concentrations of more than 100 ng/L are present. 1.4 Units—The values stated in picoCurie per liter units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1....

  2. The investigation of the neutron emission spectra of {sup 232}Th and {sup 238}U for neutron incident energy from 2 to 18 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Tel, Eyyup [Gazi University, Faculty of Arts and Science, Department of Physics, Ankara (Turkey); Sahin, Haci Mehmet [Gazi University, Faculty of Technical Education, Department of Mechanical Education, 06503 Teknikokullar, Ankara (Turkey)]. E-mail: mesahin@gazi.edu.tr; Arasoglu, Ali [Yuezuencue Yil University, Faculty of Arts and Science, Department of Physics, Van (Turkey); Aytekin, Hueseyin [Karaelmas University, Faculty of Arts and Science, Department of Physics, Zonguldak (Turkey)

    2006-03-15

    In this study, experimental neutron-emission spectra produced by (n, xn) reactions on nuclei {sup 232}Th have been compared with experimental {sup 238}U(n, xn) neutron-emission spectra from 2 to 18 MeV. Angle-integrated cross-sections in neutron induced reactions on targets {sup 238}U have been calculated at the bombarding energies from 2 to 18 MeV. In the calculations, the geometry dependent hybrid model and the cascade exciton model including the effects of pre-equilibrium have been used. In addition, we have described how multiple pre-equilibrium emissions can be included in the Feshbach-Kerman-Koonin (FKK) fully quantum-mechanical theory. By analyzing (n, xn) reaction on {sup 238}U with the incident energy from 2 to 18 MeV, the importance of multiple pre-equilibrium emission can be seen clearly. All calculated results have been compared with experimental data. The obtained results have been discussed and compared with the available experimental data and found agreement with each other.

  3. CREATING THE KULTUK POLYGON FOR EARTHQUAKE PREDICTION: VARIATIONS OF (234U/238U) AND 87SR/86SR IN GROUNDWATER FROM ACTIVE FAULTS AT THE WESTERN SHORE OF LAKE BAIKAL

    OpenAIRE

    S. V. Rasskazov; E. P. Chebykin; A. M. Ilyasova; E. N. Vodneva; I. S. Chuvashova; S. A. Bornyakov; A. K. Seminsky; S. V. Snopkov; V. V. Chechel'nitsky; N. A. Gileva

    2015-01-01

    Introduction. Determinations of (234U/238U) in groundwater samples are used for monitoring current deformations in active faults (parentheses denote activity ratio units). The cyclic equilibrium of activity ratio 234U/238U≈≈(234U/238U)≈γ≈1 corresponds to the atomic ratio ≈5.47×10–5. This parameter may vary due to higher contents of 234U nuclide in groundwater as a result of rock deformation. This effect discovered by P.I. Chalov and V.V. Cherdyntsev was described in [Cherdyntsev, 1969, 1973; ...

  4. The metrological activity determination of {sup 238} U and {sup 230} Th by gamma spectrometry to industrial fuel-cycle application

    Energy Technology Data Exchange (ETDEWEB)

    Almeida M, M.C. de; Delgado, J.U.; Poledna, R. [Instituto de Radioprotecao e Dosimetria- IRD/SEMRA, CNEN, Av. Salvador Allende s/n, Recreio, CEP 22780-160, Rio de Janeiro (Brazil)]. e-mail: marcandida@yahoo.com.br

    2006-07-01

    This work describes the difficulty for determining the activity of {sup 238} U and {sup 230} Th using gamma spectrometry due to the low gamma-ray emission probabilities of 92 and 67 keV, and, mainly, the associated high uncertainties about 13 and 11%, respectively. {sup 230} Th is a {sup 238} U daughter and it is product from uranium mills and refineries. {sup 230} Th decays to {sup 226} Ra and this decay has to be measured because these radionuclides are not in secular equilibrium with their daughter products, besides the gamma-energies have high uncertainties in the emission probabilities. These radionuclides, mostly {sup 238} U, are important in the nuclear fuel-cycle, since the mining of uranium ore, where the nominal isotopic content of natural uranium is 99.27% of {sup 238} U, until the irradiated fuel reprocessing, where this isotope, a fertile material, is recovered to be used again. The uranium and thorium are considered safeguarded nuclear materials and the metrology tries to calibrate and standardize these materials to improve the activity determination techniques applied in different fuel-cycle scopes. The essential characteristics of the safeguarded materials are low gamma energies (less than 100 keV) and emission probabilities but with high uncertainties. In this way, the metrology can contribute to homeland security defense against illicit nuclear trafficking with the identification and quantification of the safeguarded radionuclides such as uranium and thorium, using specific gamma window energy and high resolution planar or coaxial germanium detector. The efficiency curve is obtained from the reference source spectrum considering the photopeak areas corresponding the standard activities. This curve depends on radiation energy, sample geometry, photon attenuation (sample absorption and material absorption between sample-detector), dead time and sample-detector position. The metrological activity determinations of {sup 238} U solid sources, and of

  5. 234U/238U Disequilibria along sedimentary discontinuities in a deep formation: late diagenetic U-relocation processes vs. large scale fluid circulation evidence ?

    Science.gov (United States)

    Deschamps, P.; Hillaire-Marcel, C.; Michelot, J.-L.; Doucelance, R.; Ghaleb, B.

    2003-04-01

    This work is part of geological investigations undertaken by the French Agency for Nuclear Waste Management (ANDRA) in order to study the safety of radioactive waste repository in deep geological clay layers. The target formation, from Mesozoic sedimentary rocks of the eastern Paris basin (France), is a thick (130--145 m), 400--500 m deep, Callovo-Oxfordian argilite unit, that is over- and underlain by Oxfordian and Bathonian limestones, respectively. Borehole core samples have been analysed for their uranium content and 234U/238U isotopic composition in order to examine the state of radioactive equilibrium existing between these two radionuclides naturally occurring in the rock. Any observations of disequilibrium should allow i) to document the mobility of these actinides in such deposits, and ii) to constrain the time scale of the geological phenomena responsible for it. Highly precise and accurate (234U/238U) analyses were obtained using Multiple Collector Inductively Coupled Plasma Mass Spectrometry. The overall reproducibility, including both chemical separation and spectrometric measurement, is about 0.15% (2σ). Most samples of the target formation and its bounding rocks display secular equilibrium. However, in the Bathonian formation near the interface with the argilite layer, significant (234U/238U) disequilibria are observed along sub-horizontal sedimentary discontinuities, identified as styloliths, indicating that the process involved has been active during the last Ma. Isotopic and elemental compositions of uranium have been determined along a transect, perpendicular to a major discontinuity. The transect exhibits a symmetric pattern relative to this discontinuity with: (1) an increase of the U-concentration towards the stylolitic joint and (2) a sharp transition between significant (234U/238U) < 1 disequilibria in the stylolith to an excess of 234U ((234U/238U) = 1.05) in the vicinity of the joint, followed by a smooth decrease of the activity ratio

  6. Spatial and temporal variations of plutonium isotopes ({sup 238}Pu and {sup 239,240}Pu) in sediments off the Rhone River mouth (NW Mediterranean)

    Energy Technology Data Exchange (ETDEWEB)

    Lansard, B. [Laboratoire d' Oceanographie et de Biogeochimie, UMR 6535, CNRS/Universite de la Mediterranee, Station Marine d' Endoume, rue de la Batterie des Lions, 13007, Marseille (France)]. E-mail: bruno.lansard@lsce.cnrs-gif.fr; Charmasson, S. [Institut de Radioprotection et de Surete Nucleaire, IRSN, Laboratoire d' Etudes Radioecologiques en milieu Continental et Marin, centre IFREMER de Mediterranee, BP 330, zone portuaire de Bregaillon, 83507, La Seyne-sur-Mer Cedex (France); Gasco, C. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, Departamento de Medio Ambiante, Avenida de la Complutense 22, 28040, Madrid (Spain); Anton, M.P. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, Departamento de Medio Ambiante, Avenida de la Complutense 22, 28040, Madrid (Spain); Grenz, C. [Laboratoire d' Oceanographie et de Biogeochimie, UMR 6535, CNRS/Universite de la Mediterranee, Station Marine d' Endoume, rue de la Batterie des Lions, 13007, Marseille (France); Arnaud, M. [Institut de Radioprotection et de Surete Nucleaire, IRSN, Laboratoire d' Etudes Radioecologiques en milieu Continental et Marin, centre IFREMER de Mediterranee, BP 330, zone portuaire de Bregaillon, 83507, La Seyne-sur-Mer Cedex (France)

    2007-04-15

    The dispersion and fate of the Rhone River inputs to the Gulf of Lions (Northwestern Mediterranean Sea) have been studied through the spatial and temporal distributions of plutonium isotopes in continental shelf sediments. Plutonium isotopes ({sup 238}Pu and {sup 239,240}Pu) are appropriate tracers to follow the dispersion of particulate matter due both to their high affinity for particles and their long half-lives. In the Rhone River valley, plutonium isotopes originate from both the weathering of the catchment basin contaminated by global atmospheric fallout, and the liquid effluents released from the Marcoule reprocessing plant since 1961. This work presents a first detailed study on {sup 238}Pu and {sup 239,240}Pu distributions in sediments from the Rhone prodelta to the adjacent continental shelf, since the decommissioning of Marcoule in 1997. The vertical distribution of Pu isotopes has been analysed in a 4.75 m long core sampled in 2001 at the Rhone mouth. Despite this length, plutonium is found at the last 10 cm, manifesting the high sedimentation rate of the prodeltaic area and its ability for trapping fine-grained sediments and associated contaminants. The highest {sup 238}Pu and {sup 239,240}Pu concentrations reached 1.26 and 5.97 Bq kg{sup -1} respectively and were found within the layer 280-290 cm. The {sup 238}Pu/{sup 239,240}Pu activity ratios (AR) demonstrated an efficient and huge trapping of the Pu isotopes derived from Marcoule. The fresh sediments, located on the top of the core, show lower plutonium activity concentrations and lower {sup 238}Pu/{sup 239,240}Pu ratios. This decrease is in close relation with the shut down of the Marcoule reprocessing plant in 1997. In 2001, plutonium isotopes were also analysed in 21 surface sediments located offshore and concentrations ranged from 0.03 to 0.17 Bq kg{sup -1} for {sup 238}Pu and from 0.33 to 1.72 Bq kg{sup -1} for {sup 239,240}Pu. The {sup 238}Pu/{sup 239,240}Pu AR ranged from 0.24 close to the

  7. Multimodal Somatostatin Receptor Theranostics Using [(64)Cu]Cu-/[(177)Lu]Lu-DOTA-(Tyr(3))octreotate and AN-238 in a Mouse Pheochromocytoma Model.

    Science.gov (United States)

    Ullrich, Martin; Bergmann, Ralf; Peitzsch, Mirko; Zenker, Erik F; Cartellieri, Marc; Bachmann, Michael; Ehrhart-Bornstein, Monika; Block, Norman L; Schally, Andrew V; Eisenhofer, Graeme; Bornstein, Stefan R; Pietzsch, Jens; Ziegler, Christian G

    2016-01-01

    Pheochromocytomas and extra-adrenal paragangliomas (PHEO/PGLs) are rare catecholamine-producing chromaffin cell tumors. For metastatic disease, no effective therapy is available. Overexpression of somatostatin type 2 receptors (SSTR2) in PHEO/PGLs promotes interest in applying therapies using somatostatin analogs linked to radionuclides and/or cytotoxic compounds, such as [(177)Lu]Lu-DOTA-(Tyr(3))octreotate (DOTATATE) and AN-238. Systematic evaluation of such therapies for the treatment of PHEO/PGLs requires sophisticated animal models. In this study, the mouse pheochromocytoma (MPC)-mCherry allograft model showed high tumor densities of murine SSTR2 (mSSTR2) and high tumor uptake of [(64)Cu]Cu-DOTATATE. Using tumor sections, we assessed mSSTR2-specific binding of DOTATATE, AN-238, and somatostatin-14. Therapeutic studies showed substantial reduction of tumor growth and tumor-related renal monoamine excretion in tumor-bearing mice after treatment with [(177)Lu]Lu-DOTATATE compared to AN-238 and doxorubicin. Analyses did not show agonist-dependent receptor downregulation after single mSSTR2-targeting therapies. This study demonstrates that the MPC-mCherry model is a uniquely powerful tool for the preclinical evaluation of SSTR2-targeting theranostic applications in vivo. Our findings highlight the therapeutic potential of somatostatin analogs, especially of [(177)Lu]Lu-DOTATATE, for the treatment of metastatic PHEO/PGLs. Repeated treatment cycles, fractionated combinations of SSTR2-targeting radionuclide and cytotoxic therapies, and other adjuvant compounds addressing additional mechanisms may further enhance therapeutic outcome.

  8. {sup 232}Th/{sup 238}U in a uranium mobility estimate in an agricultural area in the municipality of Pedra-Pernambuco - Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Santos Junior, Jose Araujo dos; Amaral, Romilton dos Santos; Bezerra, Jairo Dias; Damascena, Kennedy Francys Rodrigues; Oliveira, Jose Valdez Monterazo de; Bispo, Rodrigo Cesar Bezerra, E-mail: jaraujo@ufpe.br [Departamento de Energia Nuclear - Grupo de Radioecologia (RAE). Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Silva, Cleomacio Miguel da [Universidade de Pernambuco (UPE), Petrolina, PE (Brazil). Departamento de Matematica; Rocha, Edilson Accioly [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco, Recife, PE (Brazil). Departamento de Quimica

    2011-07-01

    The mobility of the radionuclides in soil depends primarily on the physic-chemical parameters. The uranium is easily oxidized in aqueous environment, which allows its characterization with higher mobility. The Thorium is practically insoluble, mainly if the environment has organic matter and sulfates. The geochemical characteristics of the rocks, associated with the weather and metamorphism produce alterations in the concentration diagrams of the natural radionuclides in different types of soil. The ratio {sup 232}Th/{sup 238}U has been used as an indicator of oxidizing and reducing conditions. Th/U less than 2 suggests that the uranium is in its concentrated form abundantly when compared to the thorium. In reducing conditions, the value Th/U higher than 7 indicates a removal of the uranium. In this work it was possible to analyze the agricultural soil in the municipality of Pedra, Pernambuco, Brazil where there are uranium anomaly and thorium in rocky outcrops. Sixty-two samples of the horizon C soil were collected, in an area of 2 km{sup 2}, where the main uranium occurrences are located. The analyses were done by High-Resolution Gamma-Spectroscopy. In the analyses the secular equilibrium was assumed and the {sup 238}U and the {sup 232}Th specific activities were used to estimate the oxidizing and reducing conditions defining the uranium mobility in the soil. The obtained findings show that the ratio Th/U varied from 0.3 to 13.4, with average of 4.6. The biggest {sup 238}U fraction was fix (80.3%), with low mobility; the smallest fraction concentrated (6.6%) and a lixiviated intermediate fraction (13.1%). (author)

  9. Trace element distribution and 235U/238U ratios in Euphrates waters and in soils and tree barks of Dhi Qar province (southern Iraq).

    Science.gov (United States)

    Riccobono, Francesco; Perra, Guido; Pisani, Anastasia; Protano, Giuseppe

    2011-09-01

    To assess the quality of the environment in southern Iraq after the Gulf War II, a geochemical survey was carried out. The survey provided data on the chemistry of Euphrates waters, as well as the trace element contents, U and Pb isotopic composition, and PAH levels in soil and tree bark samples. The trace element concentrations and the (235)U/(238)U ratio values in the Euphrates waters were within the usual natural range, except for the high contents of Sr due to a widespread presence of gypsum in soils of this area. The trace element contents in soils agreed with the common geochemistry of soils from floodplain sediments. Some exceptions were the high contents of Co, Cr and Ni, which had a natural origin related to ophiolitic outcrops in the upper sector of the Euphrates basin. The high concentrations of S and Sr were linked to the abundance of gypsum in soils. A marked geochemical homogeneity of soil samples was suggested by the similar distribution pattern of rare earth elements, while the (235)U/(238)U ratio was also fairly homogeneous and within the natural range. The chemistry of the tree bark samples closely reflected that of the soils, with some notable exceptions. Unlike the soils, some tree bark samples had anomalous values of the (235)U/(238)U ratio due to mixing of depleted uranium (DU) with the natural uranium pool. Moreover, the distribution of some trace elements (such as REEs, Th and Zr) and the isotopic composition of Pb in barks clearly differed from those of the nearby soils. The overall results suggested that significant external inputs occurred implying that once formed the DU-enriched particles could travel over long distances. The polycyclic aromatic hydrocarbon concentrations in tree bark samples showed that phenanthrene, fluoranthene and pyrene were the most abundant components, indicating an important role of automotive traffic. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. The radiochemical contamination (210Po and 238U of zone around phosphogypsum waste heap in Wiślinka (northern Poland

    Directory of Open Access Journals (Sweden)

    Boryło A.

    2013-04-01

    Full Text Available The aim of this work was the determination of the impact of phosphogypsum waste heap in Wiślinka (northern Poland for radiological protection of zone around waste heap. The activity of 210Po, 234U, and 238U were measured using an alpha spectrometer. The values of uranium and polonium concentration in water with immediate area of waste heap are considerably higher than in the waters of the Martwa Wisła river. The values of activity ratio 234U/238U are approximately about one in the phosphogypsum (0.97±0.05 and in the water of retention reservoir and pumping station (0.92±0.01 and 0.99±0.08, while in the water from the Martwa Wisła river they are slightly higher than one (1.03±0.07 and 1.17±0.06. In the analyzed plants species the highest amounts of polonium and uranium were found in ruderal plants samples as well as hygrophilous plant samples. The more amounts of 210Po and 238U radionuclides were accumulated mainly in the roots of the analyzed plant species. The significant source of polonium and uranium in the natural environment is dry and wet atmospheric fallout in the immediate vicinity of phosphogypsum waste heap and the transfer via root for distant areas. The general conclusion of realized study is higher influence of phosphogypsum on radioactive contamination of environmental zone around heap waste in Wiślinka (northern Poland.

  11. Tumour necrosis factor -308 and -238 promoter polymorphisms are predictors of a null virological response in the treatment of Brazilian hepatitis C patients

    Directory of Open Access Journals (Sweden)

    Tarciana Grandi

    2014-06-01

    Full Text Available Certain host single nucleotide polymorphisms (SNPs affect the likelihood of a sustained virological response (SVR to treatment in subjects infected with hepatitis C virus (HCV. SNPs in the promoters of interleukin (IL-10 (-1082 A/G, rs1800896, myxovirus resistance protein 1 (-123 C/A, rs17000900 and -88 G/T, rs2071430 and tumour necrosis factor (TNF (-308 G/A, rs1800629 and -238 G/A, rs361525 genes and the outcome of PEGylated α-interferon plus ribavirin therapy were investigated. This analysis was performed in 114 Brazilian, HCV genotype 1-infected patients who had a SVR and in 85 non-responders and 64 relapsers. A significantly increased risk of having a null virological response was observed in patients carrying at least one A allele at positions -308 [odds ratios (OR = 2.58, 95% confidence intervals (CI = 1.44-4.63, p = 0.001] or -238 (OR = 7.33, 95% CI = 3.59-14.93, p < 0.001 in the TNF promoter. The risk of relapsing was also elevated (-308: OR = 2.87, 95% CI = 1.51-5.44, p = 0.001; -238: OR = 4.20, 95% CI = 1.93-9.10, p < 0.001. Multiple logistic regression of TNF diplotypes showed that patients with at least two copies of the A allele had an even higher risk of having a null virological response (OR = 16.43, 95% CI = 5.70-47.34, p < 0.001 or relapsing (OR = 6.71, 95% CI = 2.18-20.66, p = 0.001. No statistically significant association was found between the other SNPs under study and anti-HCV therapy response.

  12. Precise determination of the absolute intensities of the gamma-ray lines of {sup 235}U and some {sup 238}U daughters

    Energy Technology Data Exchange (ETDEWEB)

    Al-Saleh, F.S. [Physics Department, Girls College of Education in Riyadh (Saudi Arabia)]. E-mail: ferdoasalsaleh@hotmail.com; Al-Mukren, Al-J.H. [Physics Department, Girls College of Education in Riyadh (Saudi Arabia); Farouk, M.A. [NCNSRC, AEA Cairo (Egypt)

    2006-12-01

    The intensities of some gamma-ray lines emitted from {sup 234}Th and {sup 234}Pa are usually used to estimate the concentrations of {sup 238}U in different environmental samples. However, the absolute intensity values currently available for some gamma-ray lines which are used for determination of these concentrations seem to be inaccurate and include some discrepancies. In the present work, the absolute intensity values for some gamma-ray lines of {sup 235}U, {sup 234}Th and {sup 234}Pa have been studied and precisely evaluated using a hyper pure germanium high-resolution gamma spectrometer.

  13. High-precision Measurement of the 238U(n,γ) Cross Section with the Total Absorption Calorimeter (TAC) at n_TOF, CERN

    CERN Document Server

    Wright, T; Billowes, J; Ware, T; Cano-Ott, D; Mendoza, E; Massimi, C; Mingrone, F; Gunsing, F; Berthoumieux, E; Lampoudis, C; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Bečvář, F; Belloni, F; Boccone, V; Bosnar, D; Brugger, M; Calviani, M; Calviño, F; Carrapiço, C; Cerutti, F; Chiaveri, E; Chin, M; Colonna, N; Cortés, G; Cortés-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Dzysiuk, N; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; García, A R; Gómez-Hornillos, M B; Gonçalves, I F; González-Romero, E; Griesmayer, E; Giubrone, G; Gurusamy, P; Jenkins, D G; Jericha, E; Kadi, Y; Käppeler, F; Karadimos, D; Kivel, N; Koehler, P; Kokkoris, M; Korschinek, G; Krtička, M; Kroll, J; Langer, C; Lederer, C; Leeb, H; Leong, L S; Losito, R; Manousos, A; Marganiec, J; Martínez, T; Mastinu, P F; Mastromarco, M; Meaze, M; Mengoni, A; Milazzo, P M; Mirea, M; Mondelaers, W; Paradela, C; Pavlik, A; Perkowski, J; Pignatari, M; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Roman, F; Rubbia, C; Sarmento, R; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Versaci, R; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Weigand, M; Weiß, C; Žugec, P

    2014-01-01

    The neutron capture cross section of U-238 is fundamental to the design and operation of current reactors and future fast nuclear reactors, and thus must be measured to a high level of accuracy. An experiment has been performed at the CERN n TOF facility using a 4 pi Total Absorption Calorimeter (TAC) to measure the capture cross section in the resolved resonance region between 1 eV and 25 keV. A preliminary analysis of the TAC data is presented with particular emphasis to the experimental background in this energy region of interest.

  14. Plants as bio-monitors for Cs-137, Pu-238, Pu-239,240 and K-40 at the Savannah River Site.

    Science.gov (United States)

    Caldwell, Eric Frank; Duff, Martine C; Ferguson, Caitlin E; Coughlin, Daniel P

    2011-05-01

    The Savannah River Site was constructed in South Carolina to produce plutonium (Pu) in the 1950s. Discharges associated with these now-ceased operations have contaminated large areas within the site, particularly streams associated with reactor cooling basins. Evaluating the exposure risk of contamination to an ecosystem requires methodologies that can assess the bioavailability of contaminants. Plants, as primary producers, represent an important mode of transfer of contaminants from soils and sediments into the food chain. The objective of this study was to identify local area plants for their ability to act as bio-monitors of radionuclides. The concentrations of cesium-137 ((137)Cs), potassium-40 ((40)K), (238)Pu and (239,240)Pu in plants and their associated soils were determined using γ and α spectrometry. The ratio of contamination concentration found in the plant relative to the soil was calculated to assess a concentration ratio (CR). The highest CR for (137)Cs was found in Pinus palustris needles (CR of 2.18). The correlation of soil and plant (137)Cs concentration was strong (0.76) and the R(2) (0.58) from the regression was significant (p = 0.006). This suggests the ability to predict the degree of (137)Cs contamination of a soil through analysis of the pine needles. The (238)Pu and (239,240)Pu concentrations were most elevated within the plant roots. Extremely high CR values were found in Sparganium americanum (bur-reed) roots with a value of 5.86 for (238)Pu and 5.66 for (239,240)Pu. The concentration of (40)K was measured as a known congener of (137)C. Comparing (40)K and (137)C concentrations in each plant revealed an inverse relationship for these radioisotopes. Correlating (40)K and (137)Cs was most effective in identifying plants that have a high affinity for (137)Cs uptake. The P. palustris and S. americanum proved to be particularly strong accumulators of all K congeners from the soil. Some species that were measured, warrant further

  15. Studies of the Vertical Distribution of Cs-134, Cs-137, Pu-238, Pu-239,240, Pu-241, Am-241 and Pb-210 in ombrogenous mires in Ireland

    Science.gov (United States)

    McGarry, A. T.; Mitchell, P. I.

    The technique of using Pb-210, a member of the naturally occurring U-238 chain, as a dating tool, has been widely used since the 1960's and has been shown to be reliable when applied to ombrotrophic peat bogs. Its application rests on two fundamental assumptions (a) that the flux of Pb-210 is constant when averaged over periods of at least a few years and (b) that Pb-210 is essentially immobile in peat over the range of natural conditions usually encountered…

  16. Accurate measurements of fission-fragment yields in 234,235,236,238U(γ,f with the SOFIA set-up

    Directory of Open Access Journals (Sweden)

    Chatillon A.

    2016-01-01

    Full Text Available SOFIA (Studies On Fission with Aladin is a new experimental set-up dedicated to accurate measurement of fission-fragments isotopic yields. It is located at GSI, the only place to use inverse kinematics at relativistic energies in order to study the (γ,f electromagnetic-induced fission. The SOFIA set-up is a large-acceptance magnetic spectrometer, which allows to fully identify both fission fragments in coincidence on the whole fission-fragment range. This paper will report on fission yields obtained in 234,235,236,238U(γ,f reactions.

  17. Accurate measurements of fission-fragment yields in 234,235,236,238U(γ,f) with the SOFIA set-up

    Science.gov (United States)

    Chatillon, A.; Taïeb, J.; Martin, J.-F.; Pellereau, E.; Boutoux, G.; Gorbinet, T.; Grente, L.; Bélier, G.; Laurent, B.; Alvarez-Pol, H.; Ayyad, Y.; Benlliure, J.; Caamaño, M.; Audouin, L.; Casarejos, E.; Cortina-Gil, D.; Farget, F.; Fernández-Domínguez, B.; Heinz, A.; Jurado, B.; Kelić-Heil, A.; Kurz, N.; Lindberg, S.; Löher, B.; Nociforo, C.; Paradela, C.; Pietri, S.; Ramos, D.; Rodriguez-Sanchez, J.-L.; Rodrìguez-Tajes, C.; Rossi, D.; Schmidt, K.-H.; Simon, H.; Tassan-Got, L.; Törnqvist, H.; Vargas, J.; Voss, B.; Weick, H.; Yan, Y.

    2016-03-01

    SOFIA (Studies On Fission with Aladin) is a new experimental set-up dedicated to accurate measurement of fission-fragments isotopic yields. It is located at GSI, the only place to use inverse kinematics at relativistic energies in order to study the (γ,f) electromagnetic-induced fission. The SOFIA set-up is a large-acceptance magnetic spectrometer, which allows to fully identify both fission fragments in coincidence on the whole fission-fragment range. This paper will report on fission yields obtained in 234,235,236,238U(γ,f) reactions.

  18. POLIMORFISTIE GEN TNF-q G-238A DAN IL-4 T-34C SERTA HUBUNGAN DENGAN KADAR IL-4 DAN TNF-q PASIEN PENYAKIT GRAVES

    Directory of Open Access Journals (Sweden)

    Raveinal Raveinal

    2014-12-01

    Full Text Available Pendahuluan: Penyakit Graves adalah hipertiraidisme ditandai pembesaran tiroid difus dengan penyebab imunologi. Kondisi autoimun dengan adanya antibodi lmunoglobulin G (lgG yang mengikat dan mengaktifkan reseptor tirotropin. Pemberian PTU dapat menurunkan hormon tiroid mencapai normal akan tetapi kadar lL-4 tidak pernah mencapai nilai normal. Penyakit Graves di Taiwan didapatkan polimorfisme gen promotor sitokin TNF-q G-238A, sedangkan gen IL-4 tidak berbeda dibanding kontrol sehat. Tujuan penelitian ini adalah mengetahui danmenganalis polimorfrsme TNF-o G-238A dan gen ll-i T-34C serta hubungannya dengan antibcCr tiroid, kadar lL-4 dan TNF-q pasien penyakit Graves. Metode: Penelitian ini merupakan penelitian deskriptif analitik, dengan jumlah sampel 35 orang pasien penyakit Graves di RSUP Dr. M. Djamil Padang. Darah vena diambil sebanyak 10 cc untuk isolasi DNA, kadar TNF-q dan lL-4. Pemeriksaan polimorfisme gen gen TNF-o G-238Adan IL-4 T-34C dengan teknik PCR-RFLP menggunakan enzym retriksi /'lzlsp/ dan Mnll serta dielektroporesis pada agarose 2%. Pemeriksaan TNF-q dan kadar IL-4 rnengunakan teknik ELISA. Analisis statistik untuk polimorfisme gen dengan uji Chi-Square dan untuk melihat hubungan antar variabel menggunakan uji ANOVA. Hasil: Didapatkan polimorfisme TNF-q G-238A dengan distribusi alel GG (91,4%, GA (8,6% dan AA (0%. Frekuensi alel G adalah 95,99% dan alel A 4,3%.Rerata kadar TNF-q adalah 62,8+16,6 pg/ml. Polimorfisme gen lL-4 T-34C dengan distribusi alel TT t28,6 % ,TC ( 28,6 oA , CC (42,9 %. Frekuensi alel T adalah 42,9 % dan alel C adalah 57,1 %. Rerata kadar lL-4 adalah sebesar 22,8 t9,4 pg/ml. Kesimpulan: penelitian ini dapat disimpulkan bahwa polimorfisme gen lL-4 T-34C lebih tinggi didapatkan pada penderita penyakit Graves dan terdapat kaiian antara polimorfisme gen inidengan peningkatan kadar IL-4. Kemungkinan adanya kaitan antara polimorfisme gen lL-4 T-34C dengan kejadian penyakit Graves.

  19. Comparison of the (p,xn) cross sections from /sup 238/U, /sup 235/U, and /sup 232/Th targets irradiated with 200-MeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Y.Y.; Zhou, M.L.

    1982-01-01

    We have measured absolute cross sections for (p,xn) reactions (x ranges from 0 to 8) from /sup 238/U, /sup 235/U, and /sup 232/Th targets irradiated with 200-MeV protons at the Brookhaven AGS Linac injector. Chemical yields were determined by using /sup 239/Np and /sup 233/Pa as tracers. Yield patterns obtained in this work can be compared to the experimental results and theoretical calculations from earlier work, and they are consistent within the framework of intranuclear cascade followed by neutron evaporation and fission competition.

  20. Multifragment emission observed for the reaction /sup 36/Ar + /sup 238/U at /ital E///ital A/=35 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. D.; Tsang, M. B.; Gelbke, C. K.; Lynch, W. G.; Carlin, N.; Chen, Z.; Fox, R.; Gong, W. G.; Murakami, T.; Nayak, T. K.; and others

    1989-07-31

    The dependence of multifragment-emission processes upon linear momentum transfer to the target residue is determined for /sup 36/Ar-induced reactions on /sup 238/U at /ital E///ital A/=35 MeV. Significantly more intermediate-mass fragments are emitted in central collisions. Multiplicity distributions for intermediate-mass fragments emitted behind the grazing angle resemble Poisson distributions and are consistent with a stochastic production process. Exit channels with up to five intermediate-mass fragments and two fission fragments were observed.

  1. High-precision Measurement of the 238U(n,γ) Cross Section with the Total Absorption Calorimeter (TAC) at n_TOF, CERN

    Science.gov (United States)

    Wright, T.; Guerrero, C.; Billowes, J.; Ware, T.; Cano-Ott, D.; Mendoza, E.; Massimi, C.; Mingrone, F.; Gunsing, F.; Berthoumieux, E.; Lampoudis, C.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Boccone, V.; Bosnar, D.; Brugger, M.; Calviani, M.; Calviño, F.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M. A.; Diakaki, M.; Domingo-Pardo, C.; Duran, I.; Dressler, R.; Dzysiuk, N.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A. R.; Gómez-Hornillos, M. B.; Gonçalves, I. F.; González-Romero, E.; Griesmayer, E.; Giubrone, G.; Gurusamy, P.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Kokkoris, M.; Korschinek, G.; Krtička, M.; Kroll, J.; Langer, C.; Lederer, C.; Leeb, H.; Leong, L. S.; Losito, R.; Manousos, A.; Marganiec, J.; Martínez, T.; Mastinu, P. F.; Mastromarco, M.; Meaze, M.; Mengoni, A.; Milazzo, P. M.; Mirea, M.; Mondelaers, W.; Paradela, C.; Pavlik, A.; Perkowski, J.; Pignatari, M.; Plompen, A.; Praena, J.; Quesada, J. M.; Rauscher, T.; Reifarth, R.; Riego, A.; Roman, F.; Rubbia, C.; Sarmento, R.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Tagliente, G.; Tain, J. L.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M. J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Weigand, M.; Weiß, C.; Žugec, P.

    2014-05-01

    The neutron capture cross section of 238U is fundamental to the design and operation of current reactors and future fast nuclear reactors, and thus must be measured to a high level of accuracy. An experiment has been performed at the CERN n_TOF facility using a 4π Total Absorption Calorimeter (TAC) to measure the capture cross section in the resolved resonance region between 1 eV and 25 keV. A preliminary analysis of the TAC data is presented with particular emphasis to the experimental background in this energy region of interest.

  2. Data Evaluation of Actinide Cross Sections: 238Pu, 237Pu, and 236Pu

    Energy Technology Data Exchange (ETDEWEB)

    Guaglioni, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jurgenson, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Descalle, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thompson, I. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ormand, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Escher, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Younes, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mattoon, C. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Beck, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Burke, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bailey, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-10-04

    This report documents the recent evaluation of the 236Pu, 237Pu, and 238Pu cross section sets. Nuclear data evaluation is the fundamental interface that takes measured nuclear cross section data and turns them into a continuous curve that 1) is consistent with other measurements and nuclear reaction theory/models, and 2) is required by down-stream users. All experiments that generate nuclear data need to include an evaluation step for their data to be broadly useful to the end users.

  3. Measurement of electro-sprayed 238 and 239+240 plutonium isotopes using 4{pi}-alpha spectrometry. Application to environmental samples; Spectrometrie alpha 4{pi} de sources d'actinides realisees par electronebulisation. Developpement et optimisation d'un protocole applique au mesurage des isotopes 238 et 239+240 du plutonium dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Charmoille-Roblot, M. [CEA/Fontenay-aux-Roses, Dept. de Protection de l' Environnement (DPRE), 92 (France)]|[Paris-11 Univ., 91 - Orsay (France)

    1999-07-01

    A new protocol for plutonium deposition using the electro-spray technique coupled with 4{pi}-{alpha} spectrometry is proposed to improve the detection limit, shorten the counting time. In order to increase the detection efficiency, it was proposed to measure 238 and 239+240 plutonium isotopes electro-sprayed deposit simultaneously on both sides of the source support, that must be as transparent as possible to alpha-emissions, in a two-alpha detectors chamber. A radiochemical protocol was adapted to electro-spray constraints and a very thin carbon foil was selected for 4{pi} -alpha spectrometry. The method was applied to a batch of sediment samples and gave the same results as an electrodeposited source measured using conventional alpha spectrometry with a 25 % gain on counting time and 10 % on plutonium 238 detection limit. Validation and application of the technique have been made on reference samples. (author)

  4. Origin of the {sup 238}U-{sup 230}Th disequilibrium in magmas from subduction zones: the Arenal example; Origine du desequilibre {sup 238}U-{sup 230}TH dans les magmas des zones de subduction: exemple de l`Arenal

    Energy Technology Data Exchange (ETDEWEB)

    Villemant, B. [Paris-6 Univ., 75 (France)

    1996-12-31

    The existence in some volcanic products of strong excess of {sup 238}U with respect to {sup 230}Th is one of the characteristics of volcanic arc magmas. These excesses are generally attributed to fluid additions inside mantellic sources before magma segregation, differentiation and eruption. These fluids should be linked to the dehydration of the subducted rocks. These hypotheses are essentially based on correlations between {sup 10}Be, {sup 87}Sr anomalies, Ba/La ratios and on the distribution of volcanic centers with respect to the subduction zone. Recent studies suggest an evolution of the composition of volcanic sources in Central America from a depleted mantle type (MORB) in the North (Nicaragua) to a less transformed enriched type (OIB) in the South (Costa Rica). The Arenal volcano belongs to a transition zone between these two types. The preliminary study of trace elements and {sup 238}U-{sup 230}Th disequilibria in recent volcanic products (1968-1993) indicates a more complex situation. At least two different mantle sources were successively involved characterized by different Th/La and La/Yb ratios and very different to the OIB type. Also most lavas are in equilibrium with {sup 238}U/{sup 232}Th ratios of about 1.2 to 1.3. However, in eruptive cycle, some lavas are characterized by a strong {sup 238}U excess with respect to {sup 230}Th with cannot be linked to the sources, even when modified by fluids in depth. These results are interpreted in terms of heterogeneities of mantle sources and low depths late interactions with hydrothermal fluids during eruptions. Abstract only. (J.S.). 2 refs.

  5. Automated absolute activation analysis with californium-252 sources

    Energy Technology Data Exchange (ETDEWEB)

    MacMurdo, K.W.; Bowman, W.W.

    1978-09-01

    A 100-mg /sup 252/Cf neutron activation analysis facility is used routinely at the Savannah River Laboratory for multielement analysis of many solid and liquid samples. An absolute analysis technique converts counting data directly to elemental concentration without the use of classical comparative standards and flux monitors. With the totally automated pneumatic sample transfer system, cyclic irradiation-decay-count regimes can be pre-selected for up to 40 samples, and samples can be analyzed with the facility unattended. An automatic data control system starts and stops a high-resolution gamma-ray spectrometer and/or a delayed-neutron detector; the system also stores data and controls output modes. Gamma ray data are reduced by three main programs in the IBM 360/195 computer: the 4096-channel spectrum and pertinent experimental timing, counting, and sample data are stored on magnetic tape; the spectrum is then reduced to a list of significant photopeak energies, integrated areas, and their associated statistical errors; and the third program assigns gamma ray photopeaks to the appropriate neutron activation product(s) by comparing photopeak energies to tabulated gamma ray energies. Photopeak areas are then converted to elemental concentration by using experimental timing and sample data, calculated elemental neutron capture rates, absolute detector efficiencies, and absolute spectroscopic decay data. Calculational procedures have been developed so that fissile material can be analyzed by cyclic neutron activation and delayed-neutron counting procedures. These calculations are based on a 6 half-life group model of delayed neutron emission; calculations include corrections for delayed neutron interference from /sup 17/O. Detection sensitivities of < or = 400 ppB for natural uranium and 8 ppB (< or = 0.5 (nCi/g)) for /sup 239/Pu were demonstrated with 15-g samples at a throughput of up to 140 per day. Over 40 elements can be detected at the sub-ppM level.

  6. Metastable charge-transfer state of californium(iii) compounds.

    Science.gov (United States)

    Liu, Guokui; Cary, Samantha K; Albrecht-Schmitt, Thomas E

    2015-06-28

    Among a series of anomalous physical and chemical properties of Cf(iii) compounds revealed by recent investigations, the present work addresses the characteristics of the optical spectra of An(HDPA)3·H2O (An = Am, Cm, and Cf), especially the broadband photoluminescence from Cf(HDPA)3·H2O induced by ligand-to-metal charge transfer (CT). As a result of strong ion-ligand interactions and the relative ease of reducing Cf(iii) to Cf(ii), a CT transition occurs at low energy (transfer state undergoes radiative and non-radiative relaxations. Broadening of the CT transition arises from strong vibronic coupling and hole-charge interactions in the valence band. The non-radiative relaxation of the metastable CT state results from a competition between phonon-relaxation and thermal tunneling that populates the excited states of Cf(iii).

  7. Initial Design Calculations for a Detection System that will Observe Resonant Excitation of the 680 keV state in 238U

    Energy Technology Data Exchange (ETDEWEB)

    Pruet, J; Hagmann, C

    2007-01-26

    We present calculations and design considerations for a detection system that could be used to observe nuclear resonance fluorescence in {sup 238}U. This is intended as part of an experiment in which a nearly monochromatic beam of light incident on a thin foil of natural uranium resonantly populates the state at 680 keV in {sup 238}U. The beam of light is generated via Compton upscattering of laser light incident on a beam of relativistic electrons. This light source has excellent energy and angular resolution. In the current design study we suppose photons emitted following de-excitation of excited nuclei to be observed by a segmented array of BGO crystals. Monte Carlo calculations are used to inform estimates for the design and performance of this detector system. We find that each detector in this array should be shielded by about 2 cm of lead. The signal to background ratio for each of the BGO crystals is larger than ten. The probability that a single detector observes a resonant photon during a single pulse of the light source is near unity.

  8. Calculation of dose rate conversion factors for (238)U, (232)TH and (40)K in concrete structures of various dimensions, with application to Nis, Serbia.

    Science.gov (United States)

    Manic, Vesna; Manic, Goran; Nikezic, Dragoslav; Krstic, Dragana

    2012-12-01

    The absorbed gamma dose rate in indoor air due to natural radionuclides in concrete as a building material was determined in this work. The dose rate conversion factors for (238)U, (232)Th and (40)K, for standard rooms as well as rooms with different sets of dimensions, were evaluated by the point kernel technique, using Harima (geometric progression) build-up factors. The values of the conversion factors, in units (nGy h(-1) (Bq kg(-1))(-1)) calculated for the standard room are: 0.76, 0.91 and 0.070, respectively for (238)U, (232)Th and (40)K. The fitting formula was obtained for dose rate conversion factors, enabling them to be conveniently calculated for a room with arbitrary dimensions. For concrete block samples collected in the area of Niš, Serbia, the measurement of the radionuclide activity concentrations was also carried out. The evaluated absorbed dose rate conversion factors were then applied in the assessment of corresponding indoor gamma dose rates, finding that all the concrete samples fulfilled the usage requirement.

  9. The Association of Inbreeding With Lung Fibrosis Incidence in Beagle Dogs That Inhaled 238PuO2 or 239PuO2.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Dulaney A.; Brigantic, Andrea M.; Morgan, William F.

    2011-09-12

    Studies of health effects in animals after exposure to internally deposited radionuclides were intended to supplement observational studies in humans. Both nuclear workers and Beagle dogs have exhibited plutonium associated lung fibrosis; however, the dogs smaller gene pool may limit the applicability of findings to humans. Data on Beagles that inhaled either plutonium-238 dioxide (238PuO2) or plutonium-239 dioxide (239PuO2) were analyzed. Wright's Coefficient of Inbreeding was used to measure genetic or familial susceptibility and was assessed as an explanatory variable when modeling the association between lung fibrosis incidence and plutonium exposure. Lung fibrosis was diagnosed in approximately 80% of the exposed dogs compared with 23.7% of the control dogs. The maximum degree of inbreeding was 9.4%. Regardless of isotope, the addition of inbreeding significantly improved the model in female dogs but not in males. In female dogs an increased inbreeding coefficient predicted decreased hazard of a lung fibrosis diagnosis. Lung fibrosis was common in these dogs with inbreeding affecting models of lung fibrosis incidence in females but not in males. The apparent protective effect in females predicted by these models of lung fibrosis incidence is likely to be minimal given the small degree of inbreeding in these groups.

  10. Distribution of 238U, 232Th, 40K, and 137Cs concentrations in soil samples nearby a nuclear laboratory, Capao Island, Brazil

    Directory of Open Access Journals (Sweden)

    Oliveira Luciano S.R.

    2015-01-01

    Full Text Available Absolute soil concentrations of 238U, 232Th, 40K, and 137Cs samples were measured using high-resolution gamma spectrometry. The area of interest encompasses an embankment in a mangrove swamp in Guaratiba, Rio de Janeiro, called Capao Island, where nuclear, chemical and biological defense laboratories of the Brazilian Army Technology Center are in operation for more than 30 years. In order to ensure that no significant environmental impact has resulted from neutron physics experiments performed in a graphite exponential pile in addition to the operation of two cesium-driven irradiating facilities, radiation monitoring of the isotopes was carried out. A total of eight 250 ml soil samples were extracted within an area of 300 m x 300 m. No trace of 137Cs was detected and the measured levels of 238U were found to be close to the global mean. However, some data that slightly exceeded the expected normal range for 232Th (60 % of samples and 40K (20 % of samples should be attributed to the construction debris (cement, rocks, and sand used in the embankment at the site. Since there is no handling of those isotopes at that site or adjacent facilities that could affect their presence, it was concluded that no detectable contamination has occurred.

  11. Potential human health risk by 234,238U and 210Po due to consumption of fish from the "Luis L. Leon" reservoir (Northern Mexico)

    Science.gov (United States)

    Luna-Porres, M. Y.; Rodríguez-Villa, M. A.; Herrera-Peraza, E.; Cabral-Lares, M.; Renteria-Villalobos, M.; Montero-Cabrera, M. E.

    2014-07-01

    The Conchos River is one of the most important in northern Mexico and the main surface waterway in the arid state of Chihuahua. The Luis L. Leon dam produces the Luis L. Leon Reservoir, which is the last major reservoir before the Conchos River enters the Rio Grande at the Texas-Chihuahua border. Activity concentrations (AC) of 234,238U and 210Po in fillet and liver of three stocked fish species (Lepomis cyanellus, Cyprinus carpio and Ictalurus furcatus), as well as in water from the Luis L. Leon reservoir were determined. 238U and 234U ACs in fillet samples showed values of 0.007-0.014 and 0.01-0.02 Bq kg-1 wet weight (ww), respectively. Liver samples for Lepomis cyanellus, Cyprinus carpio and Ictalurus furcatus species, present 210Po AC of 1.16-3.26 0.70-1.13 and 0.93-1.37 Bqṡkg-1 ww. The elemental Bioaccumulation Factor (BAF) for fish tissues respect to their concentrations in water was determined. Lepomis cyanellus species showed the highest BAF for total uranium in fillet, with value 1.5. The annual effective dose for uranium in adults by fish consumption in this work ranged from 4.46×10-3 to 3.68×10-2 μSvṡyear-1. The difference in concentrations of uranium in fillet among the studied species is likely primarily due to their differences in diet and habitat.

  12. Nuclear charge distribution of fission products originated from fission of 238U nuclei induced by45-69 MeV protons

    Directory of Open Access Journals (Sweden)

    Houshyar Noshad

    2007-12-01

    Full Text Available  Fission of 238U nuclei was performed by 45-69 MeV protons at the Cyclotron and Radioisotope Center of Tohoku University in Japan. The fission products originated in the reaction were identified by using gamma spectroscopy. The experimental data show that the charge distribution of isobar fission products follows a Gaussian distribution with a standard deviation independent of the selected mass number. The standard deviations were measured for the reaction 238U(p, f with 45, 55, 65 and 69 MeV protons. For Ep = 45 MeV, the standard deviation obtained from the experiment is in agreement with the existing data and satisfies the prediction of the Hauser-Feshbach statistical model. For other proton energies, measurement of this quantity has not been reported in the literature. The experimental results show that the value of standard deviation increases, when the excitation energy of the fissioning nucleus increases. Furthermore, the most probable charge was determined for the isobar fission products detected in the experiment. The results are consistent with the prediction of the minimum potential energy (MPE model. Moreover, the experimental data show that nuclear charge polarization occurs in the fission process.

  13. Seasonal variations of total {sup 234}Th and dissolved {sup 238}U concentration activities in surface water of Bransfield Strait, Antarctica, from March to October 2011

    Energy Technology Data Exchange (ETDEWEB)

    Lapa, Flavia V.; Oliveira, Joselene de; Costa, Alice M.R., E-mail: fvlapa@ipen.br, E-mail: jolivei@ipen.br, E-mail: lice_mrc@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil). Laboratorio de Radiometria Ambiental; Braga, Elisabete S., E-mail: edsbraga@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. Oceanografico. Lab. de Nutrientes, Micronutrientes e Tracos nos Oceanos

    2013-07-01

    In this study the naturally occurring radionuclides {sup 234}Th and {sup 238}U were used to investigate the magnitude of upper ocean particulate organic carbon export in Bransfield Strait, Southern Ocean. This region is the largest oceanic high-nitrate low-chlorophyll (HNLC) area in the world and is known to contribute to regulate of the atmospheric CO{sub 2} via the biological pump. Due to its different geochemical behavior in seawater, the resulting U/Th disequilibria can be easily used to constrain the transport rates of particles and reaction processes between solution and particulate phases. Sampling occurred during the summer (March and November) 2011. Total {sup 234}Th activities in surface seawater samples ranged from 1.3 to 3.7 dpm L{sup -1} (station EB 011) during March/11 campaign, while in October/11 total {sup 234}Th activity concentrations varied from 1.4 to 2.9 dpm L{sup -1}. Highest total {sup 234}Th activities were found late in the austral summer season. Activity concentrations of dissolved {sup 238}U in surface seawater varied from 2.1 to 2.4 dpm L{sup -1}. Taking into account all sampling stations established in March and October/11 the relative variability of total {sup 234}Th distribution was 22%. (author)

  14. Transfer of {sup 238}U, {sup 230}Th, {sup 226}Ra, and {sup 210}Pb from soils to tree and shrub species in a Mediterranean area

    Energy Technology Data Exchange (ETDEWEB)

    Blanco Rodriguez, P. [Natural Radioactivity Group, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz (Spain); Vera Tome, F. [Natural Radioactivity Group, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz (Spain)], E-mail: fvt@unex.es; Lozano, J.C. [Natural Radioactivity Group, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz (Spain); Laboratorio de Radiaciones Ionizantes, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca (Spain); Perez Fernandez, M.A. [Natural Radioactivity Group, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz (Spain); Area de Ecologia, Universidad Pablo Olavide, Carretera de Utrera km. 1, 41013 Sevilla (Spain)

    2010-06-15

    The soil-to-plant transfer factors of natural uranium isotopes ({sup 238}U and {sup 234}U), {sup 230}Th, {sup 226}Ra, and {sup 210}Pb were studied in a disused uranium mine located in the Extremadura region in the south-west of Spain. The plant samples included trees (Quercus ilex, Quercus suber, and Eucalyptus cameldulensis) and one shrub (Cytisus multiflorus). All of them are characteristic of Mediterranean environments. The activity concentrations in leaves and fruit were determined for the tree species at different stages of growth. For the shrub, the total above-ground fraction was considered in three seasons. For old leaves and fruit, the highest activity concentrations were found in Eucalyptus cameldulensis for all the radionuclides studied, except in the case of {sup 230}Th that presented similar activity concentrations in all of the tree species studied. In every case, the transfer to fruit was less than the transfer to leaves. In the shrub, the results depended on the season of sampling, with the highest value obtained in spring and the lowest in autumn. Important correlations were obtained for {sup 238}U and {sup 226}Ra between the activity ratio in soils with that in leaves or fruit.

  15. Accurate 238U(n , 2 n )237U reaction cross-section measurements from 6.5 to 14.8 MeV

    Science.gov (United States)

    Krishichayan, Bhike, M.; Tornow, W.; Tonchev, A. P.; Kawano, T.

    2017-10-01

    The cross section for the 238U(n ,2 n )237U reaction has been measured in the incident neutron energy range from 6.5 to 14.8 MeV in small energy steps using an activation technique. Monoenergetic neutron beams were produced via the 2H(d ,n )3He and 3H(d ,n )4He reactions. 238U targets were activated along with Au and Al monitor foils to determine the incident neutron flux. The activity of the reaction products was measured in TUNL's low-background counting facility using high-resolution γ -ray spectroscopy. The results are compared with previous measurements and latest data evaluations. Statistical-model calculations, based on the Hauser-Feshbach formalism, have been carried out using the CoH3 code and are compared with the experimental results. The present self-consistent and high-quality data are important for stockpile stewardship and nuclear forensic purposes as well as for the design and operation of fast reactors.

  16. Characterization of {sup 238}U, {sup 232}Th, {sup 40}K, and {sup 226}Ra in NORM and Air Particulate Occurring from Phosphate Processing Facility

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yoon Hee; Lim, Jong Myoung; Ji, Young Yong; Kim, Hyun Cheol; Kim, Chang Jong; Park, Ji Yong; Chung, Kun Ho; Kang, Mun Ja [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this study, radio-activities of {sup 238}U, {sup 232}Th, {sup 40}K, and {sup 226}Ra occurring in raw materials and by-products at phosphate processing facility were complementally determined using ED-XRF, γ-spectrometry and ICP-MS method. Although the degree of immersion in the human body varies depending on the particle size and density, the particle size is especially used as a key factor in assessing dose. Thus, size distribution characteristics of {sup 238}U concentrations in airborne particulates collected at the phosphate processing facility were also evaluated. The naturally occurring radioactive materials (NORM) are widely spread throughout the environment, it occupies the largest part of public radioactivity exposure. According to report of the US National Academy of Sciences, 82% of the human radiation dose received annually comes from the natural radionuclides. Radiation exposure doses from natural radionuclides is not significantly concerned level compared to those from artificial radionuclides which could be released into the environment by nuclear tests and power plant accident. It could make a serious risk problem to unspecific public when exposed to the natural radionuclides during long-term period at high activity concentration levels. Therefore, it is essential to make a professional and systematic approach for the proper handling and diminution.

  17. Uranium-238 and thorium-232 series concentrations in soil, radon-222 indoor and drinking water concentrations and dose assessment in the city of Alameda, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero Sujo, L.; Montero Cabrera, M.E. E-mail: elena.montero@cimav.edu.mx; Villalba, L.; Renteria Villalobos, M.; Torres Moye, E.; Garcia Leon, M.; Garcia-Tenorio, R.; Mireles Garcia, F.; Herrera Peraza, E.F.; Sanchez Aroche, D

    2004-07-01

    High-resolution gamma spectrometry was used to determine the concentration of {sup 40}K, {sup 238}U and {sup 232}Th series in soil samples taken from areas surrounding the city of Aldama, in Chihuahua. Results of indoor air short-time sampling, with diffusion barrier charcoal detectors, revealed relatively high indoor radon levels, ranging from 29 to 422 Bq/m{sup 3}; the radon concentrations detected exceeded 148 Bq/m{sup 3} in 76% of the homes tested. Additionally, liquid scintillation counting showed concentrations of radon in drinking water ranging from 4.3 to 42 kBq/m{sup 3}. The high activity of {sup 238}U in soil found in some places may be a result of the uranium milling process performed 20 years ago in the area. High radon concentrations indoor and in water may be explained by assuming the presence of uranium-bearing rocks underneath of the city, similar to a felsic dike located near Aldama. The estimated annual effective dose of gamma radiation from the soil and radon inhalation was 3.83 mSv.

  18. Transfer of 238U, 230Th, 226Ra, and 210Pb from soils to tree and shrub species in a Mediterranean area.

    Science.gov (United States)

    Blanco Rodríguez, P; Vera Tomé, F; Lozano, J C; Pérez Fernández, M A

    2010-06-01

    The soil-to-plant transfer factors of natural uranium isotopes ((238)U and (234)U), (230)Th, (226)Ra, and (210)Pb were studied in a disused uranium mine located in the Extremadura region in the south-west of Spain. The plant samples included trees (Quercus ilex, Quercus suber, and Eucalyptus cameldulensis) and one shrub (Cytisus multiflorus). All of them are characteristic of Mediterranean environments. The activity concentrations in leaves and fruit were determined for the tree species at different stages of growth. For the shrub, the total above-ground fraction was considered in three seasons. For old leaves and fruit, the highest activity concentrations were found in Eucalyptus cameldulensis for all the radionuclides studied, except in the case of (230)Th that presented similar activity concentrations in all of the tree species studied. In every case, the transfer to fruit was less than the transfer to leaves. In the shrub, the results depended on the season of sampling, with the highest value obtained in spring and the lowest in autumn. Important correlations were obtained for (238)U and (226)Ra between the activity ratio in soils with that in leaves or fruit. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. Distinguishing lower and upper crustal processes in magmas erupted during the buildup to the 7.7 ka climactic eruption of Mount Mazama, Crater Lake, Oregon, using 238U-230Th disequilibria

    Science.gov (United States)

    Ankney, Meagan E.; Johnson, Clark M.; Bacon, Charles R.; Beard, Brian L.; Jicha, Brian R.

    2013-08-01

    Uranium-series isotope ratios determined for 35 volcanic rocks and 4 glass separates erupted from ~36 to 4.8 ka at Mt. Mazama, Crater Lake, Oregon, identify both 230Th-excess and 238U-excess components. U-Th isotope compositions cover a wide range, exceeding those previously measured for the Cascade arc. Age-corrected (230Th/232Th) and (238U/232Th) activity ratios range from 1.113 to 1.464 and from 0.878 to 1.572 (44.4 % 230Th-excess to 8.8 % 238U-excess), respectively. The most distinctive aspect of the data set is the contrast in U-Th isotope ratios between low and high Sr (LSr, HSr) components that have been previously identified in products of the 7.7 ka caldera-forming climactic eruption and preclimactic rhyodacite lavas. The LSr component exclusively contains 238U-excess, but the HSr component, as well as more primitive lavas, are marked by 230Th-excess. 230Th-excesses such as those recorded at Mt. Mazama are commonly observed in the Cascades. Melting models suggest that high 230Th-excesses observed in the more primitive lavas evolved through mixing of a mantle melt with a partial melt of a mafic lower crustal composition that contained garnet in the residuum that was produced through dehydration melting of amphibolite that was initially garnet free. Dehydration melting in the lower crust offers a solution to the "hot-slab paradox" of the Cascades, where low volatile contents are predicted due to high slab temperatures, yet higher water contents than expected have been documented in erupted lavas. The 238U-excess observed at Mt. Mazama is rare in Cascade lavas, but occurs in more than half of the samples analyzed in this study. Traditionally, 238U-excess in arc magmas is interpreted to reflect slab fluid fluxing. Indeed, 238U-excess in arcs is common and likely masks 230Th-excess resulting from lower crustal interaction. Isotopic and trace element data, however, suggest a relatively minor role for slab fluid fluxing in the Cascades. We propose that 238U

  20. 234U/238U Disequilibrium along stylolitic discontinuities in deep Mesozoic limestone formations of the Eastern Paris basin: evidence for discrete uranium mobility over the last 1–2 million years

    Directory of Open Access Journals (Sweden)

    P. Deschamps

    2004-01-01

    Full Text Available The (234U/238 equilibrium state of borehole core samples from the deep, low-permeability limestone formations surrounding the target argilite layer of the Meuse/Haute-Marne experimental site of the French agency for nuclear waste management -ANDRA- (Agence nationale pour la gestion des déchets radioactifs was examined to improve understanding of naturally occurring radionuclide behaviour in such geological settings. Highly precise, accurate MC-ICP-MS measurements of the (234U/238U activity ratio show that limestone samples characterised by pressure dissolution structures (stylolites or dissolution seams display systematic (234U/238U disequilibria, while the pristine carbonate samples remain in the secular equilibrium state. The systematic feature is observed throughout the zones marked by pressure dissolution structures: (i the material within the seams shows a deficit of 234U over 238U ((234U/238U down to 0.80 and (ii the surrounding carbonate matrix is characterised by an activity ratio greater than unity (up to 1.05. These results highlight a centimetric-scale uranium remobilisation in the limestone formations along these sub-horizontal seams. Although their nature and modalities are not fully understood, the driving processes responsible for these disequilibria were active during the last 1–2 Ma. Keywords: uranium isotopes, multiple-collector ICP-MS, waste management, remobilisation, migration

  1. Tumor necrosis factor-alpha G-238A polymorphism and coronary artery disease risk: a meta-analysis of 4,222 patients and 4,832 controls

    Directory of Open Access Journals (Sweden)

    Hua XP

    2015-09-01

    Full Text Available Xian-Ping Hua,1,* Xiao-Dong Zhang,2,* Joey SW Kwong,3,* Xian-Tao Zeng,4 Zhen-Jian Zhang,1 Wan-Lin Wei21Department of Cardiology, Suizhou Hospital, Hubei University of Medicine, Suizhou, Hubei Province, 2Department of Cardiology and 4th Cadres Ward, General Hospital of Beijing Military Command, Beijing, 3Chinese Evidence-Based Medicine Center and Chinese Cochrane Center, West China Hospital, Sichuan University, Chengdu, 4Center for Evidence-Based and Translational Medicine, Zhongnan Hospital, Wuhan University, Wuhan, People’s Republic of China*These authors contributed equally to this workBackground: The aim of the present study was to investigate the association between tumor necrosis factor-alpha (TNF-α gene G-238A polymorphism and risk of coronary artery disease (CAD using a meta-analytical approach.Methods: The PubMed and Embase databases were searched for relevant publications up to January 13, 2015. Four authors (XPH, XDZ, XTZ, and ZJZ independently selected the studies, extracted, and analyzed the data using the Comprehensive Meta-Analysis software. The sensitivity and subgroups analyses were also performed. Either a fixed effects or a random effects model was used to estimate pooled odds ratios (ORs and their 95% confidence intervals (CIs.Results: Finally, ten articles including eleven case-control studies involving 4,222 patients and 4,832 controls were yielded. The results indicated no significant association between G-238A polymorphism and CAD risk (A vs G: OR =1.08, 95% CI =0.89–1.30; AA vs GG: OR =1.15, 95% CI =0.59–2.25; GA vs GG: OR =1.14, 95% CI =0.88–1.48; AA vs [GG + GA]: OR =1.09, 95% CI =0.56–2.14; (GA + AA vs GG: OR =1.11, 95% CI =0.90–1.38. In the subgroup analyses, similar results were obtained with overall populations. The sensitivity analyses showed that the overall results were robust. No publication bias was detected.Conclusion: Based on current evidence, we can conclude that TNF-α G-238A polymorphism

  2. {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am levels in the terrestrial and aquatic environment of the Loire and Garonne rivers basins (France)

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, G.; Mokili, M.B.; Le Roy, C.; Pagano, V. [SUBATECH/IN2P3 (France); Gontier, G.; Boyer, C. [EDF-DPI-DIN-CIDEN (France); Chardon, P. [CNRS/IN2P3 (France); Hemidy, P.Y. [EDF-DPN-UNIE-GPRE-IEV (France)

    2014-07-01

    Plutonium and americium long-lived alpha emitter isotopes can be found in the environment because of atmospheric global fallout due to thermonuclear tests performed between 1945 and 1980, to the American SNAP 9A satellite explosion in 1964, to the Chernobyl nuclear power plant accident,... In France, the nuclear safety authority does not allow the release of artificial alpha emitters from nuclear power plants. Thus, monitoring is performed to verify the absence of these alpha emitters in liquid discharges to respect the limits set by the regulations. These thresholds ensure a very low dosimetric impact to the population compared to other radionuclides. With the objective of environmental monitoring around nuclear facilities, activity measurements of long-lived alpha emitters are carried out to detect the traces of these radionuclides. Analysis of low activity by alpha spectrometry after chemical steps were performed and used to determine the {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am activities on a large set of environmental solid samples likely to be encountered in environmental monitoring as soils, sediments, terrestrial and aquatic bio-indicators. The samples collected in the terrestrial and aquatic environment of the Loire and Garonne rivers basins (France) was investigated for the 2009-2014 period. It was found that the mean activity concentration of the most frequently detected was for the radionuclide {sup 238}Pu: from <0.00031 to 0.0061 Bq/kg dry in terrestrial samples and from <0.00086 to 0.011 Bq/kg dry in aquatic samples; for the radionuclide {sup 239+240}Pu: from 0.00041 to 0.150 Bq/kg dry in terrestrial samples and from 0.0023 to 0.240 Bq/kg dry in aquatic samples and for the radionuclide {sup 241}Am: from <0.00086 to 0.087 Bq/kg dry in terrestrial samples and from 0.0022 to 0.120 Bq/kg dry in aquatic samples. {sup 238}Pu/{sup 239+240}Pu and {sup 241}Am/{sup 239+240}Pu ratios determined are in accordance with an environmental contamination due to

  3. TNF-alpha −308G/A and −238G/A polymorphisms and its protein network associated with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Kaiser Jamil

    2017-09-01

    Full Text Available Several reports document the role of tumor necrosis factor alpha (TNF-α and lipid metabolism in the context of acute inflammation as a causative factor in obesity-associated insulin resistance and as one of the causative parameter of type 2 diabetes mellitus (T2DM. Our aim was to investigate the association between −308G/A and −238G/A polymorphisms located in the promoter region of the TNF-α gene in T2DM in the Indian population with bioinformatics analysis of TNF-α protein networking with an aim to find new target sites for the treatment of T2DM. Demographics of 100 diabetes patients and 100 healthy volunteers were collected in a structured proforma and 3 ml blood samples were obtained from the study group, after approval of Institutional Ethics Committee of the hospital (IEC. The information on clinical parameters was obtained from medical records. Genomic DNA was extracted; PCR–RFLP was performed using TNF-α primers specific to detect the presence of SNPs. Various bioinformatics tools such as STRING software were used to determine its network with other associated genes. The PCR–RFLP studies showed that among the −238G/A types the GG genotype was 87%, GA genotype was 12% and AA genotype was 1%. Almost a similar pattern of results was obtained with TNF-α −308G/A polymorphism. The results obtained were evaluated statistically to determine the significance. By constructing TNF-α protein interaction network we could analyze ontology and hubness of the network to identify the networking of this gene which may influence the functioning of other genes in promoting T2DM. We could identify new targets in T2DM which may function in association with TNF-α. Through hub analysis of TNF-α protein network we have identified three novel proteins RIPK1, BIRC2 and BIRC3 which may contribute to TNF-mediated T2DM pathogenesis. In conclusion, our study indicated that some of the genotypes of TNF-α −308G/A, −238G/A were not significantly

  4. The Reactivations of Main-Belt Comets 238P/READ, 259P/Garradd, and 288P/(300163) 2006 VW139

    Science.gov (United States)

    Hsieh, Henry H.; Ishiguro, Masateru; Kim, Yoonyoung; Knight, Matthew M.; Lin, Zhong-Yi; Micheli, Marco; Moskovitz, Nicholas; Sheppard, Scott S.; Thirouin, Audrey; Trujillo, Chadwick

    2017-10-01

    We report on the confirmation and monitoring of recurrent activity for main-belt comets (MBCs) 238P/Read and 288P/(300163) 2006 VW139 in 2016 (cf. Agarwal et al. 2016, CBET 4306; Hsieh et al. 2016, CBET 4307), as well as the identification of activity for 288P in Sloan Digital Sky Survey images from November 2000. We will also report on the confirmation of recurrent activity in 2017 (Hsieh et al. 2017, CBET 4388) and the progress of the ongoing monitoring campaign (April 2017 through December 2017) that we are conducting for MBC 259P/Garradd. With these observations, 238P and 288P have now each been observed to be active on three separate orbit passages with intervening periods of inactivity and 259P has been observed to be active on two separate orbit passages, firmly establishing the cometary (i.e., sublimation-driven) nature of their activity. We are currently conducting a multi-facility observing campaign to monitor the photometric and morphological evolution of these objects, using the Canada-France-Hawaii Telescope, the Gemini North and South telescopes (under a Gemini Large and Long Program), the Magellan telescopes, the Discovery Channel Telescope, and the Lulin One-meter Telescope. During their most recent perihelion encounters, 238P was observed to be active as early as 2016 July 8 at a true anomaly of 329 degrees, 288P was observed to be active as early as 2016 June 8 at a true anomaly of 318 degrees, and 259P was observed to be active as early at 2017 April 26 at a true anomaly of 315 degrees. We also report on the results of numerical modeling analyses of the morphological evolution of all three objects aimed at assessing both the properties of their current active episodes and changes in activity strength from one epoch to the next to help constrain the active lifetimes of MBCs, a key parameter for inferring the total number of MBCs in the asteroid belt from survey results. This work was supported by the NASA Solar System Observations program under

  5. Standard practice for the determination of 237Np, 232Th, 235U and 238U in urine by inductively coupled plasma-Mass spectrometry (ICP-MS) and gamma ray spectrometry.

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This practice covers the separation and preconcentration of neptunium-237 (237Np), thorium-232 (232Th), uranium-235 (235U) and uranium-238 (238U) from urine followed by quantitation using ICP-MS. 1.2 This practice can be used to support routine bioassay programs. The minimum detectable concentrations (MDC) for this method, taking the preconcentration factor into account, are approximately 1E-2Bq for 237Np (0.38ng), 2E-6Bq for 232Th (0.50ng), 4E-5Bq for 235U (0.50ng) and 6E-6Bq for 238U (0.48ng). 1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  6. Biological effects of implanted nuclear energy sources for artificial heart devices. Progress report, September 1, 1975--August 31, 1976. [Heat dissipation from /sup 238/Pu power sources implanted in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Kallfelz, F.A.; Wentworth, R.A.; Cady, K.B.

    1976-01-01

    A total of sixty dogs were implanted with radioisotope-powered artificial heart systems producing radiation fluxes similar to that of plutonium-238, but having no associated heat, at levels of from one to seventy times the radiation flux expected from a 30-watt plutonium-238 source. Results from studies lasting up to 6 years after implantation indicate that these animals, and by inference human beings, may be able to tolerate the radiation flux from 30-watt /sup 238/Pu power sources. Results of heat dissipation studies in calves indicate that it may be possible to induce a vascularized connective tissue capsule sufficient to dissipate 30 watts of additional heat from a surface area of approximately 500 cm sq., allowing a heat flux of 0.06 watts per cm sq.

  7. Constraining the calculation of 234,236,238U (n ,γ ) cross sections with measurements of the γ -ray spectra at the DANCE facility

    Science.gov (United States)

    Ullmann, J. L.; Kawano, T.; Baramsai, B.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; O'Donnell, J. M.; Rundberg, R. S.; Vieira, D. J.; Wilhelmy, J. B.; Krtička, M.; Becker, J. A.; Chyzh, A.; Wu, C. Y.; Mitchell, G. E.

    2017-08-01

    The cross section for neutron capture in the continuum region has been difficult to calculate accurately. Previous results for 238U show that including an M 1 scissors-mode contribution to the photon strength function resulted in very good agreement between calculation and measurement. This paper extends that analysis to U,236234 by using γ -ray spectra measured with the Detector for Advanced Neutron Capture Experiments (DANCE) at the Los Alamos Neutron Science Center to constrain the photon strength function used to calculate the capture cross section. Calculations using a strong scissors-mode contribution reproduced the measured γ -ray spectra and were in excellent agreement with the reported cross sections for all three isotopes.

  8. Determination of plutonium isotopes (238Pu, 239Pu, 240Pu, 241Pu) in environmental samples using radiochemical separation combined with radiometric and mass spectrometric measurements

    DEFF Research Database (Denmark)

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin

    2014-01-01

    This paper reports an analytical method for the determination of plutonium isotopes (238Pu, 239Pu, 240Pu, 241Pu) in environmental samples using anion exchange chromatography in combination with extraction chromatography for chemical separation of Pu. Both radiometric methods (liquid scintillation...... counting and alpha spectrometry) and inductively coupled plasma mass spectrometry (ICP-MS) were applied for the measurement of plutonium isotopes. The decontamination factors for uranium were significantly improved up to 7.5×105 for 20 g soil compared to the level reported in the literature......, this is critical for the measurement of plutonium isotopes using mass spectrometric technique. Although the chemical yield of Pu in the entire procedure is about 55%, the analytical results of IAEA soil 6 and IAEA-367 in this work are in a good agreement with the values reported in the literature or reference...

  9. (238)U/(235)U isotope ratios of crustal material, rivers and products of hydrothermal alteration: new insights on the oceanic U isotope mass balance.

    Science.gov (United States)

    Noordmann, Janine; Weyer, Stefan; Georg, R Bastian; Jöns, Svenja; Sharma, Mukul

    2016-01-01

    In this study, the U isotope composition, n((238)U)/n((235)U), of major components of the upper continental crust, including granitic rocks of different age and post-Archaean shales, as well as that of rivers (the major U source to the oceans) was investigated. Furthermore, U isotope fractionation during the removal of U at mid-ocean ridges, an important sink for U from the oceans, was investigated by the analyses of hydrothermal water samples (including low- and high-temperature fluids), low-temperature altered basalts and calcium carbonate veins. All analysed rock samples from the continental crust fall into a limited range of δ(238)U between -0.45 and -0.21 ‰ (relative to NBL CRM 112-A), with an average of -0.30 ± 0.15 ‰ (2 SD, N = 11). Despite differences in catchment lithologies, all major rivers define a relatively narrow range between -0.31 and -0.13 ‰, with a weighted mean isotope composition of -0.27 ‰, which is indistinguishable from the estimate for the upper continental crust (-0.30 ‰). Only some tributary rivers from the Swiss Alps display a slightly larger range in δ(238)U (-0.29 to +0.01 ‰) and lower U concentrations (0.87-3.08 nmol/kg) compared to the investigated major rivers (5.19-11.69 nmol/kg). These findings indicate that only minor net U isotope fractionation occurs during weathering and transport of material from the continental crust to the oceans. Altered basalts display moderately enriched U concentrations (by a factor of 3-18) compared to those typically observed for normal mid-ocean ridge basalts. These, and carbonate veins within altered basalts, show large U isotope fractionation towards both heavy and light U isotope compositions (ranging from -0.63 to +0.27 ‰). Hydrothermal water samples display low U concentrations (0.3-1 nmol/kg) and only limited variations in their U isotope composition (-0.43 ± 0.25 ‰) around the seawater value. Nevertheless, two of the investigated fluids display

  10. Evaluation of cross sections for neutron interactions with {sup 238}U in the energy region between 5 keV and 150 keV

    Energy Technology Data Exchange (ETDEWEB)

    Sirakov, I. [Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria); Capote, R.; Trkov, A. [International Atomic Energy Agency, NAPC-Nuclear Data Section, Vienna (Austria); Gritzay, O. [Institute for Nuclear Research, Kyiv (Ukraine); Kim, H.I. [Korea Atomic Energy Research Institute, Nuclear Data Center, Daejeon (Korea, Republic of); Kopecky, S.; Paradela, C.; Schillebeeckx, P. [European Commission, Joint Research Centre, Geel (Belgium); Kos, B. [Jozef Stefan Institute, Ljubljana (Slovenia); Pronyaev, V.G. [Rosatom State Corporation, Atomsrandart, Moscow (Russian Federation)

    2017-10-15

    Cross sections for neutron interactions with {sup 238}U in the energy region from 5 keV to 150 keV have been evaluated. Average total and capture cross sections have been derived from a least squares analysis using experimental data reported in the literature. The resulting cross sections have been parameterised in terms of average resonance parameters maintaining full consistency with results of optical model calculations by using a dispersive coupled channel optical model potential. The average compound partial cross sections have been expressed in terms of transmission coefficients by applying the Hauser-Feshbach statistical reaction theory including width-fluctuations. A generalized single-level representation compatible with the energy-dependent options of the ENDF-6 format has been applied using standard boundary conditions. The results have been transferred into a full ENDF-6 compatible data file. (orig.)

  11. Quantification of Uncertainties due to 235,238U, 239,240,241Pu and Fission Products Nuclear Data Uncertainties for a PWR Fuel Assembly

    Science.gov (United States)

    da Cruz, D. F.; Rochman, D.; Koning, A. J.

    2014-04-01

    Uncertainty analysis on reactivity and discharged inventory for a typical PWR fuel element as a result of uncertainties in 235,238U, 239,240,241Pu, and fission products nuclear data was performed. The Total Monte-Carlo (TMC) method was applied using the deterministic transport code DRAGON. The nuclear data used in this study is from the JEFF-3.1 evaluations, with the exception of the nuclear data files for U, Pu and fission products isotopes, which are taken from the nuclear data library TENDL-2012. Results show that the calculated total uncertainty in keff (as result of uncertainties in nuclear data of the considered isotopes) is virtually independent on fuel burnp and amounts to 700 pcm. The uncertainties in inventory of the discharged fuel is dependent on the element considered and lies in the range 1-15% for most fission products, and is below 5% for the most important actinides.

  12. EFFECTIVE SPECIFIC ACTIVITY OF NATURAL RADIONUCLIDES FOR THE NORM BELONGED TO 238U AND 232TH SERIES BEING IN THE STATE OF DISTURBED RADIOACTIVE EQUILIBRIUM

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2008-01-01

    Full Text Available In the Sanitary Rules SR 2.6.1.1292-03 and SR 2.6.6.1169-02 classification of the industrial waste containing naturally occurring radioactive materials is adopted in accordance to the values of their effective specific activity Aeff. In a case of the disturbed equilibrium in 238U and 232Th series it is necessary to take into consideration actual contribution of the separate natural radionuclides of the mentioned series into the value of gamma dose rate of the waste. This will permit to avoid unjustified overestimating or understating of the waste category which prevents as unjustified expenditures on their treating so undertaking of the necessary measures providing radiation safety.

  13. Ground water contamination with (238)U, (234)U, (235)U, (226)Ra and (210)Pb from past uranium mining: cove wash, Arizona.

    Science.gov (United States)

    Dias da Cunha, Kenya Moore; Henderson, Helenes; Thomson, Bruce M; Hecht, Adam A

    2014-06-01

    The objectives of the study are to present a critical review of the (238)U, (234)U, (235)U, (226)Ra and (210)Pb levels in water samples from the EPA studies (U.S. EPA in Abandoned uranium mines and the Navajo Nation: Red Valley chapter screening assessment report. Region 9 Superfund Program, San Francisco, 2004, Abandoned uranium mines and the Navajo Nation: Northern aum region screening assessment report. Region 9 Superfund Program, San Francisco, 2006, Health and environmental impacts of uranium contamination, 5-year plan. Region 9 Superfund Program, San Franciso, 2008) and the dose assessment for the population due to ingestion of water containing (238)U and (234)U. The water quality data were taken from Sect. "Data analysis" of the published report, titled Abandoned Uranium Mines Project Arizona, New Mexico, Utah-Navajo Lands 1994-2000, Project Atlas. Total uranium concentration was above the maximum concentration level for drinking water (7.410-1 Bq/L) in 19 % of the water samples, while (238)U and (234)U concentrations were above in 14 and 17 % of the water samples, respectively. (226)Ra and (210)Pb concentrations in water samples were in the range of 3.7 × 10(-1) to 5.55 × 102 Bq/L and 1.11 to 4.33 × 102 Bq/L, respectively. For only two samples, the (226)Ra concentrations exceeded the MCL for total Ra for drinking water (0.185 Bq/L). However, the (210)Pb/(226)Ra ratios varied from 0.11 to 47.00, and ratios above 1.00 were observed in 71 % of the samples. Secular equilibrium of the natural uranium series was not observed in the data record for most of the water samples. Moreover, the (235)U/(total)U mass ratios ranged from 0.06 to 5.9 %, and the natural mass ratio of (235)U to (total)U (0.72 %) was observed in only 16 % of the water samples, ratios above or below the natural ratio could not be explained based on data reported by U.S. EPA. In addition, statistical evaluations showed no correlations among the distribution of the radionuclide concentrations

  14. High-accuracy determination of the 238U/235U fission cross section ratio up to ≈1 GeV at n_TOF at CERN

    Science.gov (United States)

    Paradela, C.; Calviani, M.; Tarrío, D.; Leal-Cidoncha, E.; Leong, L. S.; Tassan-Got, L.; Le Naour, C.; Duran, I.; Colonna, N.; Audouin, L.; Mastromarco, M.; Lo Meo, S.; Ventura, A.; Aerts, G.; Altstadt, S.; Álvarez, H.; Álvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Badurek, G.; Barbagallo, M.; Baumann, P.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthier, B.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calviño, F.; Cano-Ott, D.; Capote, R.; Carrapiço, C.; Cennini, P.; Cerutti, F.; Chiaveri, E.; Chin, M.; Cortés, G.; Cortés-Giraldo, M. A.; Cosentino, L.; Couture, A.; Cox, J.; David, S.; Diakaki, M.; Dillmann, I.; Domingo-Pardo, C.; Dressler, R.; Dridi, W.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Finocchiaro, P.; Fraval, K.; Fujii, K.; Furman, W.; Ganesan, S.; García, A. R.; Giubrone, G.; Gómez-Hornillos, M. B.; Gonçalves, I. F.; González-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Haight, R.; Heil, M.; Heinitz, S.; Igashira, M.; Isaev, S.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Ketlerov, V.; Kivel, N.; Kokkoris, M.; Konovalov, V.; Krtička, M.; Kroll, J.; Lampoudis, C.; Langer, C.; Lederer, C.; Leeb, H.; Losito, R.; Lozano, M.; Manousos, A.; Marganiec, J.; Martínez, T.; Marrone, S.; Massimi, C.; Mastinu, P.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Mondelaers, W.; Moreau, C.; Mosconi, M.; Musumarra, A.; O'Brien, S.; Pancin, J.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perkowski, J.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, L.; Poch, A.; Pretel, C.; Praena, J.; Quesada, J.; Rauscher, T.; Reifarth, R.; Riego, A.; Roman, F.; Rudolf, G.; Rubbia, C.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tavora, L.; Terlizzi, R.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Versaci, R.; Vermeulen, M. J.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Wallner, A.; Walter, S.; Ware, T.; Weigand, M.; Weiß, C.; Wiesher, M.; Wisshak, K.; Wright, T.; Žugec, P.; n TOF Collaboration

    2015-02-01

    The 238U to 235U fission cross section ratio has been determined at n_TOF up to ≈1 GeV, with two different detection systems, in different geometrical configurations. A total of four datasets has been collected and compared. They are all consistent to each other within the relative systematic uncertainty of 3-4%. The data collected at n_TOF have been suitably combined to yield a unique fission cross section ratio as a function of neutron energy. The result confirms current evaluations up to 200 MeV. Good agreement is also observed with theoretical calculations based on the INCL ++/ Gemini++ combination up to the highest measured energy. The n_TOF results may help solve a long-standing discrepancy between the two most important experimental datasets available so far above 20 MeV, while extending the neutron energy range for the first time up to ≈1 GeV.

  15. Identification of New Neutron-Rich Isotopes in the Rare-Earth Region Produced by 345 MeV/nucleon 238U

    Science.gov (United States)

    Fukuda, Naoki; Kubo, Toshiyuki; Kameda, Daisuke; Inabe, Naohito; Suzuki, Hiroshi; Shimizu, Yohei; Takeda, Hiroyuki; Kusaka, Kensuke; Yanagisawa, Yoshiyuki; Ohtake, Masao; Tanaka, Kanenobu; Yoshida, Koichi; Sato, Hiromi; Baba, Hidetada; Kurokawa, Meiko; Ohnishi, Tetsuya; Iwasa, Naohito; Chiba, Ayuko; Yamada, Taku; Ideguchi, Eiji; Go, Shintaro; Yokoyama, Rin; Fujii, Toshihiko; Nishibata, Hiroki; Ieki, Kazuo; Murai, Daichi; Momota, Sadao; Nishimura, Daiki; Sato, Yoshiteru; Hwang, Jongwon; Kim, Sunji; Tarasov, Oleg B.; Morrissey, David J.; Simpson, Gary

    2018-01-01

    A search for new isotopes in the neutron-rich rare-earth region has been carried out using a 345 MeV/nucleon 238U beam at the RIKEN Nishina Center RI Beam Factory. Fragments produced were analyzed and identified using the BigRIPS in-flight separator. We observed a total of 29 new neutron-rich isotopes: 153Ba, 154,155,156La, 156,157,158Ce, 156,157,158,159,160,161Pr, 162,163Nd, 164,165Pm, 166,167Sm, 169Eu, 171Gd, 173,174Tb, 175,176Dy, 177,178Ho, and 179,180Er.

  16. High accuracy determination of the $^{238}$U/$^{235}$U fission cross section ratio up to $\\sim$1 GeV at n_TOF (CERN)

    CERN Document Server

    Paradela, C.; D.Tarr i; Leal-Cidoncha, E.; Leong, L.S.; Tassan-Got, L.; Le Naour, C.; Duran, I.; Colonna, N.; Audouin, L.; Mastromarco, M.; Lo Meo, S.; Ventura, A.; Altstadt, S.; Andrzejewski, J.; Barbagallo, M.; Becares, V.; Becvar, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calvino, F.; Cano-Ott, D.; Carrapico, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Cortes, G.; Cortes-Giraldo, M.A.; Cosentino, L.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Eleftheriadis, C.; Ferrari, A.; Finocchiaro, P.; Fraval, K.; Ganesan, S.; A.R.Garc i; Giubrone, G.; Gomez-Hornillos, M.B.; Goncalves, I.F.; Gonzalez-Romero, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Heinitz, S.; Jenkins, D.G.; Jericha, E.; Kappeler, F.; Karadimos, D.; Kivel, N.; Kokkoris, M.; Krticka, M.; Kroll, J.; Langer, C.; Lederer, C.; Leeb, H.; Losito, R.; Manousos, A.; Marganiec, J.; Martinez, T.; Massimi, C.; Mastinu, P.; Mendoza, E.; Mengoni, A.; Milazzo, P.M.; Mingrone, F.; Mirea, M.; Mondalaers, W.; Musumarra, A.; Pavlik, A.; Perkowski, J.; Plompen, A.; Praena, J.; Quesada, J.; Rauscher, T.; Reifarth, R.; Riego, A.; Roman, F.; Rubbia, C.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Tagliente, G.; Tain, J.L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Versaci, R.; Vermeulen, M.J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiss, C.; Wright, T.; Zugec, P.

    2015-01-01

    The $^{238}$U to $^{235}$U fission cross section ratio has been determined at n_TOF up to $\\sim$1 GeV, with two different detection systems, in different geometrical configurations. A total of four datasets have been collected and compared. They are all consistent to each other within the relative systematic uncertainty of 3-4%. The data collected at n_TOF have been suitably combined to yield a unique fission cross section ratio as a function of the neutron energy. The result confirms current evaluations up to 200 MeV. A good agreement is also observed with theoretical calculations based on the INCL++/Gemini++ combination up to the highest measured energy. The n_TOF results may help solving a long-standing discrepancy between the two most important experimental dataset available so far above 20 MeV, while extending the neutron energy range for the first time up to $\\sim$1 GeV.

  17. Experimental Neutron-Induced Fission Fragment Mass Yields of 232Th and 238U at Energies from 10 to 33 MeV

    CERN Document Server

    Simutkin, V D; Blomgren, J; Österlund, M; Bevilacqua, R; Ryzhov, I V; Tutin, G A; Yavshits, S G; Vaishnene, L A; Onegin, M S; Meulders, J P; Prieels, R

    2013-01-01

    Development of nuclear energy applications requires data for neutron-induced reactions for actinides in a wide neutron energy range. Here we describe measurements of pre-neutron emission fission fragment mass yields of 232Th and 238U at incident neutron energies from 10 to 33 MeV. The measurements were done at the quasi-monoenergetic neutron beam of the Louvain-la-Neuve cyclotron facility CYCLONE; a multi-section twin Frisch-gridded ionization chamber was used to detect fission fragments. For the peak neutron energies at 33, 45 and 60 MeV, the details of the data analysis and the experimental results have been published before and in this work we present data analysis in the low-energy tail of the neutron energy spectra. The preliminary measurement results are compared with available experimental data and theoretical predictions.

  18. A study of nuclear structure for 244Cm, 241Am, 238Pu, 210Po, 147Pm, 137Cs, 90Sr and 63Ni nuclei used in nuclear battery

    Science.gov (United States)

    Artun, Ozan

    2017-07-01

    In this paper, we intend to extend the nuclear data of 244Cm, 241Am, 238Pu, 210Po, 147Pm, 137Cs, 90Sr and 63Ni nuclei used in nuclear battery technology, because, these nuclei are quite important for space investigations in radioisotope thermoelectric generator (RTG) and for microelectronic technologies in betavoltaic batteries. Therefore, the nuclear structure properties of nuclei such as separation energies, neutron skin thicknesses, proton, charge and neutron density distributions as a function of radius, the root mean square (rms) proton, charge and neutron radii, binding energies per particle, have been investigated by Hartree-Fock with eight different Skyrme forces. The obtained results have been compared with the experimental data in literature and relativistic mean field theory (RMFT) results.

  19. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, April 1-June 30, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Matlack, G.M.; Patterson, J.H.

    1981-09-01

    The containers for /sup 238/PuO/sub 2/ heat sources in radioisotope thermoelectric generators are designed with large safety factors to ensure they will withstand reentry from orbit and impact with the earth and safely contain the nuclear fuel until it is recovered. Existing designs have proved more than adequately safe, but the Space and Terrestrial Division of the Department of Energy Office of Advanced Nuclear Systems and Projects continually seeks more information about the heat sources to improve their safety. The work discussed here includes studies of the effects on the heat source of terrestrial and aquatic environments to obtain data for design of even safer systems. This report includes data from environmental chamber experiments that simulate terrestrial conditions, experiments to measure PuO/sub 2/ dissolution rates, soil column experiments to measure sorption of plutonium by soils, and several aquatic experiments.

  20. Extensión del estándar ISO 10303 AP-238 para la automatización del acceso a datos de procesos CNC

    Directory of Open Access Journals (Sweden)

    J. Garrido

    2009-01-01

    Full Text Available Resumen: El nuevo estándar ISO 10303-AP238 (STEP-NC abre nuevas posibilidades para la comunicación de datos entre sistemas CAD/CAM y sistemas de fabricación CNC. Este artículo propone una extensión del modelo de información STEP-NC con nuevas estructuras de datos y nuevas funciones NC para contemplar capacidades de acceso a información en tiempo real del proceso de mecanizado, y apoyar a otras actividades avanzadas como la trazabilidad o la realización de los llamados procesos de mecanizado closed loop. Palabras Clave: Automatización, CAD/CAM, CNC, estándares, ISO, monitorizar, adquisición de datos

  1. Multi-residue method for determination of 238 pesticides in Chinese cabbage and cucumber by liquid chromatography-tandem mass spectrometry: comparison of different purification procedures.

    Science.gov (United States)

    Zhao, Mei-Ai; Feng, Ya-Nan; Zhu, Yong-Zhe; Kim, Jeong-Han

    2014-11-26

    This paper describes the comparison of five sample cleanup procedures for the determination of 238 pesticides via triple quadrupole liquid chromatography-tandem mass spectrometry (LC-MS/MS, with only 10 min of chromatographic running time) in Chinese cabbage and cucumber. Samples were extracted with a quick, easy, cheap, effective, rugged, and safe (QuECHERS) preparation method and cleanup with different sorbents, including primary secondary amine (PSA), multi-walled carbon nanotubes (MWCNTs), and polystyrene (PLS), to find out the most suitable cleanup methods for Chinese cabbage and cucumber. The recovery and matrix effect were evaluated by monitoring the main parameters in one group of 238 pesticides at the spiked level of 8 and 40 μg/kg. In Chinese cabbage, when PSA dispersive solid-phase extraction (D-SPE) was applied, recoveries of 183 pesticides ranged between 70 and 120% with relative standard deviation (RSD) values lower than 20% at a spiked level of 40 μg/kg, indicating the effectiveness of the purification step. In cucumber, 203 pesticides were in the 70-120% recovery range with good reproducibility by PSA mini-cartridge column cleanup at a spiked level of 40 μg/kg and RSD values were generally below 20%. The limits of quantitation [LOQs; signal-to-noise (S/N) = 10] were in the range of 0.16-10.20 μg/kg for Chinese cabbage and 0.06-21.06 μg/kg for cucumber, while the limits of detection (LODs; S/N = 3) were between 0.05 and 3.06 μg/kg and between 0.02 and 6.32 μg/kg in Chinese cabbage and cucumber, respectively. The proposed methods that might be applied for the multi-residue analysis in Chinese cabbage and cucumber are contributed to their rapid speed and good recoveries.

  2. Assessment of radiological impact in mineral industrial plants caused by deposition of wastes with U{sup 238} and/or Th{sup 232} associated

    Energy Technology Data Exchange (ETDEWEB)

    Ladeira, Paula C.; Alves, Rex Nazare, E-mail: rexnazare@ime.eb.b [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Ruperti Junior, Nerbe J., E-mail: nruperti@cnen.gov.b [Comissao Nacional de Energia Nuclear (DIREJ/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Rejeitos Radioativos

    2011-07-01

    The industrial-mining facilities constantly produce, in Brazil and in abroad, wastes from its production, many times containing uranium and/or thorium associated. Due to the large quantities generated, these wastes are usually deposited at the site of the facility, close to the place where they were produced. Since the chains of radioactive U{sup 238} and Th{sup 232} with alpha-emitting radionuclides have long half-life, waste deposits associated with these elements may cause radiological impact on the man and on the environment, even in the long term. Mathematical models are often used to represent the biosphere and the transport of radionuclides near to the surface. Thus, it was decided, through the software {sup M}athematica{sup ,} to present a methodology based on the solution of Bateman equations for the calculation of radiological impact on individuals from the public exposed to contamination. The radiological impact appraisal was carried out considering a scenario of intrusion into landfills containing U{sup 238} and / or Th{sup 232} in post-operational phase of an industrial-mining installation. The critical group examined was represented by farmers who used water from an artesian well for daily consumption and which feed themselves on vegetables locally grown in clay soil. As a result, there was the exposure in pathways evaluated, a minor contribution of dose for ingestion of contaminated water. The conclusion of this work, show us that calculated doses were within the accepted international limits for the intrusion scenario. Parameters associated with mathematical models defining the choice of project to build a landfill for the purpose of deposition, whereas rates of doses can be estimated in each of the scenarios proposed. (author)

  3. Radionuclides (40K, 232Th and 238U) and Heavy Metals (Cr, Ni, Cu, Zn, As and Pb) Distribution Assessment at Renggam Landfill, Simpang Renggam, Johor, Malaysia

    Science.gov (United States)

    Zaidi, E.; FahrulRazi, MJ; Azhar, ATS; Hazreek, ZAM; Shakila, A.; Norshuhaila, MS; Omeje, M.

    2017-08-01

    The assessment of radioactivity levels and the distribution of heavy metals in soil samples at CEP Farm landfill, Renggam in Johor State was to determine the activity concentrations of naturally occurring radionuclides and heavy metal concentrations of this landfill. The background radiation was monitored to estimate the exposure level. The activity concentrations of radionuclides in soil samples were determined using HPGe gamma ray spectroscopy whereas the heavy metal concentration was measured using X-RF analysis. The mean exposure rate at the landfill site was 36.2±2.4 μR hr-1 and the annual effective dose rate at the landfill site was 3.19 ± 0.22 mSv yr-1. However, residential area has lower mean exposure dose rate of about 16.33±0.72 μR hr-1 and has an annual effective dose rate of 1.43±0.06 mSv yr-1 compared to landfill sites. The mean activity concentration of 40K, 238U and 232Th at landfill site were 239.95±15.89 Bq kg-1, 20.90±2.49 Bq kg-1 and 40.61±4.59 Bq kg-1, respectively. For heavy metal compositions, Cr, Ni and Cu have mean concentration of 232±10 ppm, 23±2 ppm, and 46±19 ppm, respectively. Whereas, Zn has concentration of 64±9 ppm and concentration of 12±1 ppm and 71±2 ppm was estimated for As and Pb respectively. The higher activity concentration of 40K down the slope through leaching process whereas the higher activity level of 238U content at the landfill site may be attributed to the soil disruption to local equilibrium.

  4. Distribuição de Polimorfismos de Base única (SNPs no gene de TNF-alfa (-238/-308 entre pacientes com TB e outras pneumopatias: marcadores genéticos de susceptibilidade a ocorrência de TB? Single Nucleotide Polymorphisms (SNPs of the TNF-alpha (-238/-308 gene among TB and nom TB patients: susceptibility markers of TB occurrence?

    Directory of Open Access Journals (Sweden)

    Martha Maria de Oliveira

    2004-08-01

    Full Text Available INTRODUÇÃO: Fatores genéticos podem desempenhar um importante papel na susceptibilidade à tuberculose (TB ativa, e polimorfismos de base única (SNPs em diferentes genes que codificam para citocinas têm sido descritos e associados com doenças. OBJETIVOS: Investigar o quanto polimorfismo na região promotora do gene que codifica para TNF-alfa (-238 e -308 estão associados a ocorrência de TB ativa. MÉTODOS: SNPs dentro do gene de TNF-alfa foram analisados por PCR- RFLP em dois grupos de indivíduos: pacientes com TB (n = 234 e pacientes com pneumopatias não TB (n = 113. RESULTADOS: Neste estudo, o alelo -238A esteve associado significantemente com susceptibilidade à ocorrência de TB e gravidade das formas clínicas (p = 0,00002; OR = 0,15; IC = 0,06-0,36. Por outro lado, o alelo -308A esteve associado significantemente com a proteção a outras formas de doença pulmonar (p = 0,02; OR = 1,95; IC = 1,07-3,58. CONCLUSÕES: Estes resultados preliminares sugerem a importância de estudos genéticos na ocorrência da TB. São necessários outros estudos para melhorar a compreensão sobre a patogênese do M. tb.BACKGROUND: Host genetic factors may play a role in the susceptibility to active tuberculosis (TB, and several polymorphisms in different cytokine coding genes have been described and associated with diseases to date. OBJECTIVES: To investigate whether polymorphisms within the promoter region of the TNF-alpha (-238/-308 coding genes are associated to the occurrence of active TB. METHODS: SNPs within the TNF-alpha gene were analyzed by PCR-RFLP among two groups of individuals: patients with TB (n = 234, and patients non TB (n = 113. RESULTS: In this study, the presence of the -238A allele was associated with susceptibility to TB disease occurrence and severity (p = 0,00002; OR = 0,15; IC = 0,06-0,36. On the contrary, the -308A allele was associated with protection to the occurrence of another pulmonary diseases. CONCLUSIONS: These

  5. The study of the (α, α’f) reaction at 120 MeV on 232Th and 238U (I) : Fission probabilities and angular distributions in the region of the giant quadrupole resonances

    NARCIS (Netherlands)

    Plicht, J. van der; Harakeh, M.N.; van der Woude, Adriaan; David, P.; Debrus, J.; Janszen, H.; Schulze, J.

    1980-01-01

    The fission decay channel of 232Th and 238U has been investigated, using the (α, α’f) reaction at 120 MeV bombarding energy. The angular distributions of the fission fragments and the fission probabilities up to around 15 MeV excitation have been measured. No evidence for the fission decay of the

  6. Associations of TNFα -308G>A, TNFα -238G>A, IL-1α -889C>T and IL-10 -1082G>A Genetic Polymorphisms with Atopic Diseases: Asthma, Rhinitis and Dermatitis

    NARCIS (Netherlands)

    Babić, Željka; Sabolić Pipinić, Ivana; Varnai, Veda Marija; Kežić, Sanja; Macan, Jelena

    2016-01-01

    Polymorphisms of cytokine genes are an interesting focus for association studies involving atopic diseases due to their role in immune cell communications during inflammation. The aim of this study was to investigate associations of TNFα -308G>A, TNFα -238G>A, IL-1α -889C>T and IL-10 -1082G>A

  7. Study of neutron spectra using sources of {sup 241}AmBE and {sup 238}PuBe moderated in water; Estudo de espectros neutrônicos com fontes de {sup 241}AmBE e {sup 238}PuBe moderados em água

    Energy Technology Data Exchange (ETDEWEB)

    Gonçalves, Angela S.; Silva, Fellipe S.; Patrão, Karla C.S.; Fonseca, Evaldo S. da; Pereira, Walsan W., E-mail: angela.souzagon@gmail.com [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Laboratorio de Metrologia de Neutrons; Fundação Técnico-Educacional Souza Marques (FTESM), Rio de Janeiro, RJ (Brazil)

    2017-11-01

    Recent works demonstrate the increasing importance of characterizing the spectrum of neutron sources for various energies. The main objective of this study is to make the understanding of the interaction of neutrons as close as possible to the reality in which the workers act, thus allowing to act directly in the area of radioprotection. In this way, neutron fluence determination of the {sup 241}AmBe source of 0.6 TBq (16 Ci) and {sup 238} PuBe 1.8 TBq (50 Ci) free in the air and inserted in aluminium spheres of 16 cm and 20.5 cm filled with distilled water. The measurements were carried out in the low scattering laboratory of the Laboratory of Neutron Metrology, in order to obtain a more realistic spectrum. Spectrum determination is based on measurement using the Bonner multisphere spectrometer containing readings with the ball-free detector and covered with polyethylene spheres having diameters of: 5,08 cm (2″), 7,62 cm (3″), 12,70 cm (5″), 20,32 cm (8″), 25,40 cm (10″) e 30,48 cm (12″). The aim is to characterize a new moderate spectrum in water using the sources of {sup 238}PuBe and {sup 241}AmBe that may represent realistic fields in the radioprotection area useful for testing, calibration and irradiation of individual and area monitors for neutrons.

  8. Use of LabSOCS for determination of specific concentrations of {sup 40}K, {sup 238}U and {sup 232}Th in fertilizer samples; Uso de LabSOCS no calculo da eficiencia de detecao para determinacao da concentracao especifica de {sup 40}K, {sup 238}U e {sup 232}Th em amostras de fertilizantes

    Energy Technology Data Exchange (ETDEWEB)

    Garcez, Ricardo Washington Dutra; Lopes, Jose Marques; Silva, Ademir Xavier da, E-mail: rgarcez@con.ufrj.br, E-mail: marqueslopez@yahoo.com.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Domingues, Alessandro Mariano; Lima, Marco Frota, E-mail: slessandrodomingues@fisica.if.uff.br, E-mail: marcofrotalima@yahoo.com.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Biologia

    2015-07-01

    Use of fertilizer is an established practice worldwide to promote agricultural productivity increased without increasing the planted area, resulting in native forests protection and increase of the food availability. Some kinds of fertilizer have in their chemical composition some radionuclides due the origin of its feedstock, such as {sup 238}U, the {sup 232}Th, and their descendants, beyond {sup 40}K. Knowledge of the radioactivity levels in the environment is great importance to know the gamma radiation dose that the human being is exposed. For identification and quantitation of radionuclides, it was used gamma spectrometry where HPGe detector was used to obtain the spectra, and LabSOCS software for calculating the detection efficiency for each energy. The values of {sup 232}Th specific concentrations ranged from 4.1 to 368.1 Bq.Kg{sup -1} , the values of {sup 238}U specific concentrations ranged from 16.0 to 647.7 Bq.Kg{sup -1} and {sup 40}K specific concentrations ranged from 19.1 to 12713 Bq.Kg{sup -1} . Concentrations of values are consistent with those found in literature. (author)

  9. Uranium isotopic ratio measurements ({sup 235}U/{sup 238}U) by laser ablation high resolution inductively coupled plasma mass spectrometry for environmental radioactivity monitoring - {sup 235}U/{sup 238}U isotope ratio analysis by LA-ICP-MS-HR for environmental radioactivity monitoring

    Energy Technology Data Exchange (ETDEWEB)

    David, K.; Mokili, M.B.; Rousseau, G.; Deniau, I.; Landesman, C. [SUBATECH, Ecole des Mines de Nantes, Universite de Nantes, CNRS/IN2P3, 4 rue Alfred Kastler, 44307 Nantes cedex 3 (France)

    2014-07-01

    The protection of the aquatic and terrestrial environments from a broad range of contaminants spread by nuclear activities (nuclear plants, weapon tests or mining) require continuous monitoring of long-lives radionuclides that were released into the environment. The precise determination of uranium isotope ratios in both natural and potential contaminated samples is of primary concern for the nuclear safeguards and the control of environmental contamination. As an example, analysis of environmental samples around nuclear plants are carried out to detect the traces in the environment originating from nuclear technology activities. This study deals with the direct analysis of {sup 235}U/{sup 238}U isotope ratios in real environmental solid samples performed with laser ablation (LA)-HR-ICP-MS. A similar technique has already been reported for the analysis of biological samples or uranium oxide particles [1,2] but to our knowledge, this was never applied on real environmental samples. The high sensitivity, rapid acquisition time and low detection limits are the main advantages of high resolution ICP-MS for accurate and precise isotope ratio measurements of uranium at trace and ultra-trace levels. In addition, the use of laser ablation allows the analysis of solid samples with minimal preparation. A a consequence, this technique is very attractive for conducting rapid direct {sup 235}U/{sup 238}U isotope ratio analysis on a large set of various matrix samples likely to be encountered in environmental monitoring such as corals, soils, sands, sediments, terrestrial and marine bio-indicators. For the present study, LA-ICP-MS-HR analyses are performed using a New Wave UP213 nano-second Nd:YAG laser coupled to a Thermo Element-XR high resolution mass spectrometer. Powdered samples are compacted with an hydraulic press (5 tons) in order to obtain disk-shaped pellet (10-13 mm in diameter and 2 mm in thickness). The NIST612 reference glass is used for LA-ICP-MS-HR tuning and as

  10. The 238U/235U isotope ratio of the Earth and the solar system: Constrains from a gravimetrically calibrated U double spike and implications for absolute Pb-Pb ages

    Science.gov (United States)

    Weyer, Stefan; Noordmann, Janine; Brennecka, Greg; Richter, Stephan

    2010-05-01

    The ratio of 238U and 235U, the two primordial U isotopes, has been assumed to be constant on Earth and in the solar system. The commonly accepted value for the 238U/235U ratio, which has been used in Pb-Pb dating for the last ~ 30 years, was 137.88. Within the last few years, it has been shown that 1) there are considerable U isotope variations (~1.3‰) within terrestrial material produced by isotope fractionation during chemical reactions [1-3] and 2) there are even larger isotope variations (at least 3.5‰) in calcium-aluminum-rich inclusions (CAIs) in meoteorites that define the currently accepted age of the solar system [4]. These findings are dramatic for geochronology, as a known 238U/235U is a requirement for Pb-Pb dating, the most precise dating technique for absolute ages. As 238U/235U variations can greatly affect the reported absolute Pb-Pb age, understanding and accurately measuring variation of the 238U/235U ratio in various materials is critical, With these new findings, the questions also arises of "How well do we know the average U isotope composition of the Earth and the solar system?" and "How accurate can absolute Pb-Pb ages be?" Our results using a gravimetrically calibrated 233U/236U double spike IRMM 3636 [5] indicate that the U standard NBL 950a, which was commonly used to define the excepted "natural" 238U/235U isotope ratio, has a slightly lower 238U/235U of 137.836 ± 0.024. This value is indistinguishable from the U isotope compositions for NBL 960 and NBL112A, which have been determined by several laboratories, also using the newly calibrated U double spike IRMM 3636 [6]. These findings provide new implications about the average U isotope composition of the Earth and the solar system. Basalts display a very tight range of U isotope variations (~0.25-0.32‰ relative to SRM 950a). Their U isotope composition is also very similar to that of chondrites [4], which however appear to show a slightly larger spread. Accepting terrestrial

  11. Potential sources affecting the activity concentrations of 238U, 235U, 232Th and some decay products in lettuce and wheat samples.

    Science.gov (United States)

    Jeambrun, M; Pourcelot, L; Mercat, C; Boulet, B; Pelt, E; Chabaux, F; Cagnat, X; Gauthier-Lafaye, F

    2012-11-01

    The activity concentrations of radionuclides within the uranium and thorium series were determined in wheat and lettuce at five sites in France, and in their respective potential sources: crop soils of wheat and crop soils and irrigation waters of lettuce. These data were used to calculate concentration ratios and to enrich the database supported by the technical report series N°472 of the IAEA (2010). For wheat and lettuce, the activity concentrations were in the same range for all radionuclides studied, except for (210)Pb, which had higher activity concentrations in wheat, ranging between 1.3 and 11 Bq kg(−1) (fresh weight) as compared to 0.4 and 0.7 Bq kg(−1) (fresh weight) for lettuce. For wheat, the range of activity concentrations (mBq kg(−1); fresh weight) decreased as (210)Pb > (226)Ra (56–1511) ≈ (228)Ra (86–769) > (228)Th (19–176) ≈ (238)U (11–169) ≈ (234)U (12–150) ≈ (230)Th (9.08–197.18) ≈ (232)Th (8.61–121.45) > (235)U (0.53–7.9). For lettuce, it decreased as (228)Ra ( (210)Pb (409–746) > (226)Ra (30–599) ≈ (228)Th ( (238)U (8–120) ≈ (234)U (8–121) ≈ (230)Th (5.21–134.63) ≈ (232)Th (5.25–156.99) > (235)U (0.35–5.63). The species differences may reflect different plant physiologies. Through the study of activity ratios of wheat and lettuce in relation with those of the various radionuclide sources it has been possible to highlight the contribution of the main sources of natural radionuclides. Indeed, irrigation water when the uranium concentration is enhanced (>30 mBq L(−1)) contributed significantly to the activity concentration of uranium in lettuces. Concerning the high activity concentrations of (210)Pb, it could be explained by atmospheric particle deposition. The effect of soil particles resuspension and their adhesion to the plant surface seemed to be important in some cases. The soil-to-plant transfer factors were calculated for lettuce and wheat. The values were lower in wheat than in

  12. 238U–230Th–226Ra–210Pb–210Po disequilibria constraints on magma generation, ascent, and degassing during the ongoing eruption of Kīlauea

    Science.gov (United States)

    Girard, Guillaume; Reagan, Mark K.; Sims, Kenneth W. W.; Thornber, Carl; Waters, Christopher L.; Phillips, Erin H.

    2017-01-01

    The timescales of magma genesis, ascent, storage and degassing at Kīlauea volcano, Hawai‘i are addressed by measuring 238U-series radionuclide abundances in lava and tephra erupted between 1982 and 2008. Most analyzed samples represent lavas erupted by steady effusion from Pu‘u ‘Ō‘ō and Kūpahianaha from 1983 to 2008. Also included are samples erupted at the summit in April 1982 and March 2008, along the East Rift Zone at the onset of the ongoing eruption in January 1983, and during vent shifting episodes 54 and 56, at Nāpau crater in January 1997, and Kane Nui O Hamo in June 2007. In general, samples have small (∼4%) excesses of (230Th) over (238U) and ∼3 to ∼17% excesses of (226Ra) over (230Th), consistent with melting of a garnet peridotite source at melting rates between 1 × 10–3 and 5 × 10–3 kg m–3 a–1, and melting region porosity between ∼2 and ∼10%, in agreement with previous studies of the ongoing eruption and historical eruptions. A small subset of samples has near-equilibrium (230Th/238U) values, and thus were generated at higher melting rates. Based on U–Th–Ra disequilibria and Th isotopic data from this and earlier studies, melting processes and sources have been relatively stable over at least the past two centuries or more, including during the ongoing unusually long (>30 years) and voluminous (4 km3) eruption. Lavas recently erupted from the East Rift Zone have average initial (210Pb/226Ra) values of 0·80 ± 0·11 (1σ), which we interpret to be the result of partitioning of 222Rn into a persistently generated CO2-rich gas phase over a minimum of 8 years. This (210Pb) deficit implies an average magma ascent rate of ≤3·7 km a–1 from ∼30 km depth to the surface. Spatter and lava associated with vent-opening episodes erupt with variable (210Pb) deficits ranging from 0·7 to near-equilibrium values in some samples. The samples with near-equilibrium (210Pb/226Ra) are typically more

  13. Distribution of Natural (U-238, Th-232, Ra-226) and Technogenic (Sr-90, Cs-137) Radionuclides in Soil-Plants Complex Near Issyk-Kul Lake, Kyrgyzstan

    Science.gov (United States)

    Jovanovic, L.; Kaldybaev, B.; Djenbaev, B.; Tilenbaev, A.

    2012-04-01

    Researches on radionuclides distribution in the soil-plants complex provide essential information in understanding human exposure to natural and technogenic sources of radiation. It is necessary in establishing regulation relating to radiation protection. The aim of this study was the radiochemical analysis of the content natural radionuclides 238U, 232Th,226Ra and technogenic radionuclides content (90Sr, 137Cs) in soils near Issyk-Kul lake (Kyrgyzstan). Results of radiochemical analyses have shown, that the concentrations of thorium-232 are fluctuating in the limits (11.7-84.1)-10-4% in the soils. The greatest concentration of thorium-232 has been found in the light chestnut soils. The content of uranium-238 in the soils near Issyk-Kul lake is fluctuating from 2.8 up to 12.7-10-4%. Radium-226 has more migration ability in comparison with other heavy natural radionuclides. According to our research the concentrations of radium-226 are fluctuating in the limits (9.4-43.0)-10-11%. The greatest concentration of radium-226 (43,0±2,8)-10-11% has been determined in the light chestnut soil. In connection with global migration of contaminating substances, including radioactive, the special attention is given long-lived radionuclides strontium-90 and caesium-137 in food-chains, and agroecosystems. Results of radiochemical analyses have shown, that specific activity of strontium-90 is fluctuating in the range of 2.9 up to 11.1 Bq/kg, and caesium-137 from 3.7 up to 14,3 Bq/kg in the soil of agroecosystems in the region of Issyk-Kul. In soil samples down to 1 meter we have observed vertical migration of these radionuclides, they were found to accumulate on the surface of soil horizon (0-5 cm) and their specific activity sharply decreases with depth. In addition in high-mountain pastures characterized by horizontal migration of cattle in profiles of soil, it was discovered that specific activity of radionuclides are lower on the slope than at the foot of the mountain. The

  14. Geochemical and multi-isotopic (87Sr/86Sr, 143Nd/144Nd, 238U/235U) perspectives of sediment sources, depositional conditions, and diagenesis of the Marcellus Shale, Appalachian Basin, USA

    Science.gov (United States)

    Phan, Thai T.; Gardiner, James B.; Capo, Rosemary C.; Stewart, Brian W.

    2018-02-01

    We investigate sediment sources, depositional conditions and diagenetic processes affecting the Middle Devonian Marcellus Shale in the Appalachian Basin, eastern USA, a major target of natural gas exploration. Multiple proxies, including trace metal contents, rare earth elements (REE), the Sm-Nd and Rb-Sr isotope systems, and U isotopes were applied to whole rock digestions and sequentially extracted fractions of the Marcellus shale and adjacent units from two locations in the Appalachian Basin. The narrow range of εNd values (from -7.8 to -6.4 at 390 Ma) is consistent with derivation of the clastic sedimentary component of the Marcellus Shale from a well-mixed source of fluvial and eolian material of the Grenville orogenic belt, and indicate minimal post-depositional alteration of the Sm-Nd system. While silicate minerals host >80% of the REE in the shale, data from sequentially extracted fractions reflect post-depositional modifications at the mineralogical scale, which is not observed in whole rock REE patterns. Limestone units thought to have formed under open ocean (oxic) conditions have δ238U values and REE patterns consistent with modern seawater. The δ238U values in whole rock shale and authigenic phases are greater than those of modern seawater and the upper crust. The δ238U values of reduced phases (the oxidizable fraction consisting of organics and sulfide minerals) are ∼0.6‰ greater than that of modern seawater. Bulk shale and carbonate cement extracted from the shale have similar δ238U values, and are greater than δ238U values of adjacent limestone units. We suggest these trends are due to the accumulation of chemically and, more likely, biologically reduced U from anoxic to euxinic bottom water as well as the influence of diagenetic reactions between pore fluids and surrounding sediment and organic matter during diagenesis and catagenesis.

  15. Distinct 238U/235U ratios and REE patterns in plutonic and volcanic angrites: Geochronologic implications and evidence for U isotope fractionation during magmatic processes

    Science.gov (United States)

    Tissot, François L. H.; Dauphas, Nicolas; Grove, Timothy L.

    2017-09-01

    Angrites are differentiated meteorites that formed between 4 and 11 Myr after Solar System formation, when several short-lived nuclides (e.g., 26Al-26Mg, 53Mn-53Cr, 182Hf-182W) were still alive. As such, angrites are prime anchors to tie the relative chronology inferred from these short-lived radionuclides to the absolute Pb-Pb clock. The discovery of variable U isotopic composition (at the sub-permil level) calls for a revision of Pb-Pb ages calculated using an ;assumed; constant 238U/235U ratio (i.e., Pb-Pb ages published before 2009-2010). In this paper, we report high-precision U isotope measurement for six angrite samples (NWA 4590, NWA 4801, NWA 6291, Angra dos Reis, D'Orbigny, and Sahara 99555) using multi-collector inductively coupled plasma mass-spectrometry and the IRMM-3636 U double-spike. The age corrections range from -0.17 to -1.20 Myr depending on the samples. After correction, concordance between the revised Pb-Pb and Hf-W and Mn-Cr ages of plutonic and quenched angrites is good, and the initial (53Mn/55Mn)0 ratio in the Early Solar System (ESS) is recalculated as being (7 ± 1) × 10-6 at the formation of the Solar System (the error bar incorporates uncertainty in the absolute age of Calcium, Aluminum-rich inclusions - CAIs). An uncertainty remains as to whether the Al-Mg and Pb-Pb systems agree in large part due to uncertainties in the Pb-Pb age of CAIs. A systematic difference is found in the U isotopic compositions of quenched and plutonic angrites of +0.17‰. A difference is also found between the rare earth element (REE) patterns of these two angrite subgroups. The δ238U values are consistent with fractionation during magmatic evolution of the angrite parent melt. Stable U isotope fractionation due to a change in the coordination environment of U during incorporation into pyroxene could be responsible for such a fractionation. In this context, Pb-Pb ages derived from pyroxenes fraction should be corrected using the U isotope composition

  16. Determination of {sup 238}Pu, {sup 239+240}Pu, {sup 241}Pu and {sup 241}Am in radioactive waste from IPEN reactor

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Bianca; Taddei, Maria Helena T.; Cheberle, Sandra M.; Ferreira, Marcelo T., E-mail: bgeraldo@cnen.gov.b, E-mail: mhtaddei@cnen.gov.b, E-mail: scsantos@cnen.gov.b, E-mail: ferreira@cnen.gov.b [Brazilian Nuclear Energy Commission (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Lab. of Pocos de Caldas; Marumo, Julio T., E-mail: jtmarumo@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Ion exchange resin is a common type of radioactive waste arising from treatment of coolant water of the main circuit of research and nuclear power reactors. This waste contains high concentrations of fission and activation products. The management of this waste includes its characterization in order to determine and quantify specific radionuclides including those known as difficult-to-measure radionuclides (RDM). The analysis of RDMs generally involves expensive and time-consuming complex radiochemical analysis for purification and separation of the radionuclides. The objective of this work is to show an easy methodology for quantifying plutonium and americium isotopes in spent ion exchange resin, used for purification of the cooling water of the IEA-R1 reactor located at the Nuclear and Energy Research Institute, IPEN-CNEN/SP. The resins were destroyed by acid digestion, followed by purification and separation of the Pu and Am isotopes with anionic and chromatographic resins. {sup 238}Pu, {sup 239}+{sup 24}'0Pu, and {sup 24}'1Am isotopes were analyzed in an alpha spectrometer equipped with surface barrier detectors. {sup 241}Pu isotope was analyzed by liquid scintillation counting. Chemical recovery yield ranged from 73 to 98% for Pu and 77 to 98% for Am, demonstrating that the methodology is suitable for identification and quantification of the isotopes studied in spent resins. (author)

  17. Search for long-lived superheavy elements in the reaction system /sup 238/U + 9. 6-MeV/nucleon /sup 63//sub,//sup 65/Cu

    Energy Technology Data Exchange (ETDEWEB)

    Esterlund, R.A.; Molzahn, D.; Brandt, R.; Patzelt, P.; Vater, P.; Boos, A.H.; Chandratillake, M.R.; Grant, I.S.; Hemingway, J.D.; Newton, G.W.A.

    1977-01-01

    A thick /sup 238/U target has been bombarded with /sup 63//sub,//sup 65/Cu ions at an incident beam energy of 9.6 MeV/nucleon. After radiochemical separations into CdS, HgS, and La-oxalate fractions, a search for evidence of the production of superheavy elements was undertaken using Si surface-barrier detectors and mica foils simultaneously for detection of spontaneous-fission events and high-energy ..cap alpha.. emission. No evidence for the presence of superheavy elements in the samples was found. Upper limits for production cross sections for superheavy elements in each of the three chemical samples, assuming an arbitrary half-life of 100 days and a target thickness equal to the entire reaction range of the incident ions from initial energy to the reaction barrier, are as follows: (a) CdS (Z = 108--115): 1 x 10/sup -34/ cm/sup 2/; (b) HgS (Z = 112): 6 x 10/sup -35/ cm/sup 2/; (c) La-oxalate (/sup 254/Cf): 8 x 10/sup -35/ cm/sup 2/. (AIP)

  18. Alpha and conversion electron spectroscopy of {sup 238,239}Pu and {sup 241}Am and alpha-conversion electron coincidence measurements

    Energy Technology Data Exchange (ETDEWEB)

    Dion, Michael P., E-mail: michael.dion@pnnl.gov; Miller, Brian W.; Warren, Glen A.

    2016-09-11

    A technique to determine the isotopic constituents of a mixed actinide sample has been proposed by a coincident alpha-conversion electron measurement. This presents a unique signature to allow the unfolding of isotopes that possess overlapping alpha particle energy and reduce backgrounds of an unseparated sample. The work presented here are results of conversion electron spectroscopy of {sup 241}Am, {sup 238}Pu and {sup 239}Pu using a dual-stage peltier-cooled 25 mm{sup 2} silicon drift detector and alpha spectroscopy with a passivated ion implanted planar silicon detector. The conversion electron spectra were evaluated from 20–55 keV based on fits to the dominant conversion electron emissions, which allowed the relative conversion electron emission intensities to be determined. These measurements provide crucial singles spectral information and calibration to aid in the coincident measurement approach. Furthermore, an alpha-conversion electron spectrometer was assembled using the silicon based detectors described and results of a coincident spectrum analysis is reported for {sup 241}Am.

  19. Capture and Fission rate of 232-Th, 238-U, 237-Np and 239-Pu from spallation neutrons in a huge block of lead.

    CERN Document Server

    Vlachoudis, Vasilis

    2000-01-01

    The study is centered on the research of the incineration possibility of nuclear waste, by the association of a particle accelerator with a multiplying medium of neutrons, in the project "Energy Amplifier" of C. Rubbia. It consists of the experimental determination of the rates of capture and fission of certain elements (232-Th, 238-U, 237-Np and 239-Pu) subjected to a fluence of fast spallation neutrons. These neutrons are produced by the interaction of high kinetic energy protons (several GeV) provided by the CERN-PS accelerator, on a large lead solid volume. The measurement techniques used in this work, are based on the activation of elements in the lead volume and the subsequent gamma spectroscopy of the activated elements, and also by the detection of fission fragment traces. The development, of a Monte Carlo code makes it possible, on one hand, to better understand the relevant processes, and on the other hand, to validate the code, by comparison with measurements, for the design and the construction of...

  20. Vertical distribution of {sup 238}Pu, {sup 239(40)}Pu, {sup 241}Am, {sup 90}Sr and {sup 137}Cs in Austrian soil profiles

    Energy Technology Data Exchange (ETDEWEB)

    Srncik, M.; Wallner, G. [Inst. fuer Anorganische Chemie, Univ. Wien (Austria); Hrnecek, E. [ARC Seibersdorf Research GmbH, Seibersdorf (Austria); European Commission, Joint Research Centre, Inst. for Transuranium Elements, Karlsruhe (Germany); Steier, P.; Wallner, A. [Fakultaet fuer Physik, Isotopenforschung, Univ. Wien (Austria); Bossew, P. [Inst. fuer Physik und Biophysik, Univ. Salzburg (Austria)

    2008-07-01

    The occurrence of {sup 238}Pu, {sup 239(40)}Pu, {sup 241}Am, {sup 90}Sr and {sup 137}Cs in the region of Nassfeld (Salzburg, Austria) is discussed at four different locations by evaluating a depth profile for each radionuclide. Furthermore, the plutonium separated from the soil samples was measured by Accelerator Mass Spectrometry (AMS) to get information on the isotope ratio {sup 240}Pu/{sup 239}Pu. The radiochemical procedure consisted of a Pu separation step from Am and Sr by anion exchange in 8 M HNO{sub 3} after oxidation state adjustment to Pu(IV). Am and Sr were coprecipitated with calcium oxalate. Am was separated from Sr by extraction chromatography using TRU-resin. The Sr separation was performed also by extraction chromatography using Sr-resin; after coprecipitation as oxalate, {sup 90}Sr was measured in a gas proportional counter. For the determination of {sup 239(40)}Pu and {sup 241}Am by {alpha}-spectrometry thin sources were prepared by microprecipitation with NdF{sub 3}. With the respective Pu isotope ratios, it was possible to identify the global fallout as source of the contamination. This was confirmed by the ratio {sup 241}Am/{sup 239(40)}Pu. From the activity ratio {sup 90}Sr/{sup 137}Cs, it could be shown that most of these radionuclides stem from the reactor accident in Chernobyl. (orig.)

  1. Systematic experimental survey on projectile fragmentation and fission induced in collisions of {sup 238}U at 1 A GeV with lead

    Energy Technology Data Exchange (ETDEWEB)

    Enquist, T.; Benlliure, J.; Farget, F.; Schmidt, K.H.; Armbruster, P. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Bernas, M.; Tassan-Got, L. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Boudard, A.; Legrain, R.; Volant, C. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de Physique des Particules, de Physique Nucleaire et de l`Instrumentation Associee (DAPNIA); Boeckstiegel, C.; Jong, M. de [Technische Univ. Darmstadt (Germany); Dufour, J.P. [CEA Centre d`Etudes Nucleaires de Bordeaux-Gradignan, 33 - Gradignan (France)

    1999-03-01

    Projectile fragmentation and fission, induced in collisions of {sup 238}U at 1 A GeV with lead, have systematically been studied. A complete survey on the isotopic production cross sections of all elements between vanadium (Z = 23) and rhenium (Z = 75) down to a cross section of 0.1 mb is given. About 600 isotopes produced in fragmentation and about 600 isotopes produced in fission were identified in the GSI fragment separator FRS from magnetic rigidities, time-of-flight values, and the energy loss in an ionisation chamber. In addition, the velocity distributions of all these reaction products have been mapped, and the products are unambiguously attributed to the different reaction mechanisms due to their kinematical properties. The results are compared with empirical systematics and previous data. The velocity of the fragments obtained in the fission process by the Coulomb repulsion allows to reconstruct the TKE-value of the break-up and to identify the atomic number of the fissioning nucleus in hot fission. The mean velocities of light projectile fragments were found to be higher than the beam velocity. (orig.) 41 refs.

  2. 234U/238U and δ87Sr in peat as tracers of paleosalinity in the Sacramento-San Joaquin Delta of California, USA

    Science.gov (United States)

    Drexler, Judith Z.; Paces, James B.; Alpers, Charles N.; Windham-Myers, Lisamarie; Neymark, Leonid; Bullen, Thomas D.; Taylor, Howard E.

    2013-01-01

    The purpose of this study was to determine the history of paleosalinity over the past 6000+ years in the Sacramento-San Joaquin Delta (the Delta), which is the innermost part of the San Francisco Estuary. We used a combination of Sr and U concentrations, d87Sr values, and 234U/238U activity ratios (AR) in peat as proxies for tracking paleosalinity. Peat cores were collected in marshes on Browns Island, Franks Wetland, and Bacon Channel Island in the Delta. Cores were dated using 137Cs, the onset of Pb and Hg contamination from hydraulic gold mining, and 14C. A proof of concept study showed that the dominant emergent macrophyte and major component of peat in the Delta, Schoenoplectus spp., incorporates Sr and U and that the isotopic composition of these elements tracks the ambient water salinity across the Estuary. Concentrations and isotopic compositions of Sr and U in the three main water sources contributing to the Delta (seawater, Sacramento River water, and San Joaquin River water) were used to construct a three-end-member mixing model. Delta paleosalinity was determined by examining variations in the distribution of peat samples through time within the area delineated by the mixing model. The Delta has long been considered a tidal freshwater marsh region, but only peat samples from Franks Wetland and Bacon Channel Island have shown a consistently fresh signal (Browns Island) has alternated between fresh and oligohaline (0.5-5 ppt).

  3. High-resolution tephrochronology of the Wilson Creek Formation (Mono Lake, California) and Laschamp event using 238U-230Th SIMS dating of accessory mineral rims

    Science.gov (United States)

    Vazquez, Jorge A.; Lidzbarski, Marsha I.

    2012-01-01

    Sediments of the Wilson Creek Formation surrounding Mono Lake preserve a high-resolution archive of glacial and pluvial responses along the eastern Sierra Nevada due to late Pleistocene climate change. An absolute chronology for the Wilson Creek stratigraphy is critical for correlating the paleoclimate record to other archives in the western U.S. and the North Atlantic region. However, multiple attempts to date the Wilson Creek stratigraphy using carbonates and tephras yield discordant results due to open-system effects and radiocarbon reservoir uncertainties as well as abundant xenocrysts. New ion microprobe 238U-230Th dating of the final increments of crystallization recorded by allanite and zircon autocrysts from juvenile pyroclasts yield ages that effectively date eruption of key tephra beds and delimit the timing of basal Wilson Creek sedimentation to the interval between 26.8±2.1 and 61.7±1.9 ka. Tephra (Ash 15) erupted during the geomagnetic excursion originally designated the Mono Lake excursion yields an age of 40.8±1.9 ka, indicating that the event is instead the Laschamp excursion. The new ages support a depositional chronology from magnetostratigraphy that indicates quasi-synchronous glacial and hydrologic responses in the Sierra Nevada and Mono Basin to regional climate change, with intervals of lake filling and glacial-snowpack melting that are in phase with peaks in spring insolation.

  4. Gamma-Ray Emission Spectra as a Constraint on Calculations of 234,236,238U Neutron-Capture Cross Sections

    Energy Technology Data Exchange (ETDEWEB)

    Ullmann, John Leonard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kawano, Toshihiko [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bredeweg, Todd Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baramsai, Bayarbadrakh [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Couture, Aaron Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Haight, Robert Cameron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jandel, Marian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mosby, Shea Morgan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); O' Donnell, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vieira, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilhelmy, Jerry B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Becker, John A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wu, Ching-Yen [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Krticka, Milan [Charles Univ., Prague (Czech Republic)

    2015-05-28

    Neutron capture cross sections in the “continuum” region (>≈1 keV) and gamma-emission spectra are of importance to basic science and many applied fields. Careful measurements have been made on most common stable nuclides, but physicists must rely on calculations (or “surrogate” reactions) for rare or unstable nuclides. Calculations must be benchmarked against measurements (cross sections, gamma-ray spectra, and <Γγ>). Gamma-ray spectrum measurements from resolved resonances were made with 1 - 2 mg/cm2 thick targets; cross sections at >1 keV were measured using thicker targets. The results show that the shape of capture cross section vs neutron energy is not sensitive to the form of the strength function (although the magnitude is); the generalized Lorentzian E1 strength function is not sufficient to describe the shape of observed gamma-ray spectra; MGLO + “Oslo M1” parameters produces quantitative agreement with the measured 238U(n,γ) cross section; additional strength at low energies (~ 3 MeV) -- likely M1-- is required; and careful study of complementary results on low-lying giant resonance strength is needed to consistently describe observations.

  5. New prompt fission neutron spectra measurements in the 238U(n,f reaction with a dedicated setup at LANSCE/WNR

    Directory of Open Access Journals (Sweden)

    Laurent Benoit

    2017-01-01

    Full Text Available A new prompt fission neutron spectra (PFNS measurement in the 238U(n,f reaction was performed at LANSCE/WNR facility. Evaluated data show discrepancies on the low (below 1 MeV and high (above 5 MeV energy parts in the PFNS for different major and minor actinides. The goal is to improve these measurements in a wide range of incident energy. The energy of the incoming neutron, inducing the fission, and the prompt neutron energies, are measured by time-of-flight method. A dedicated fission chamber was developed, in order to improve alpha-fission discrimination, timing resolution, actinide mass, and to reduce the amount of neutron scattering. To detect prompt neutrons, the 54 Chi-Nu scintillator cells array were surrounding the fission chamber. High statistics were recorded during this experiment, allowing a precise study of PFNS behavior as a function of incident neutron energy, from 1 MeV to 200 MeV. This experiment also showed that all the new tools developed to improve PFNS measurements are performing. Therefore, measurements of PFNS with others actinides such as 239Pu are planned.

  6. Fission Fragment Mass Distributions and Total Kinetic Energy Release of 235-Uranium and 238-Uranium in Neutron-Induced Fission at Intermediate and Fast Neutron Energies

    Energy Technology Data Exchange (ETDEWEB)

    Duke, Dana Lynn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-12

    This Ph.D. dissertation describes a measurement of the change in mass distributions and average total kinetic energy (TKE) release with increasing incident neutron energy for fission of 235U and 238U. Although fission was discovered over seventy-five years ago, open questions remain about the physics of the fission process. The energy of the incident neutron, En, changes the division of energy release in the resulting fission fragments, however, the details of energy partitioning remain ambiguous because the nucleus is a many-body quantum system. Creating a full theoretical model is difficult and experimental data to validate existing models are lacking. Additional fission measurements will lead to higher-quality models of the fission process, therefore improving applications such as the development of next-generation nuclear reactors and defense. This work also paves the way for precision experiments such as the Time Projection Chamber (TPC) for fission cross section measurements and the Spectrometer for Ion Determination in Fission (SPIDER) for precision mass yields.

  7. 238 - 246_Zubair et al.,

    African Journals Online (AJOL)

    pc

    “stone breaker”, “carry me seed” etc. In Nigeria, the plant is called “geron tsuntsaye” (Hausa), “eyin- ... flowers. It is commonly found in forest areas, arid land, savannah areas, leached and exhausted soil in many countries including China, India, Nigeria, Cuba and Philippines amongst others (Burkill, 1994;. Bharatiya, 1992).

  8. Measurement of 238U and 232Th in Petrol, Gas-oil and Lubricant Samples by Using Nuclear Track Detectors and Resulting Radiation Doses to the Skin of Mechanic Workers.

    Science.gov (United States)

    Misdaq, M A; Chaouqi, A; Ouguidi, J; Touti, R; Mortassim, A

    2015-10-01

    Workers in repair shops of vehicles (cars, buses, truck, etc.) clean carburetors, check fuel distribution, and perform oil changes and greasing. To explore the exposure pathway of (238)U and (232)Th and its decay products to the skin of mechanic workers, these radionuclides were measured inside petrol, gas-oil, and lubricant material samples by means of CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs), and corresponding annual committed equivalent doses to skin were determined. The maximum total equivalent effective dose to skin due to the (238)U and (232)Th series from the application of different petrol, gas-oil, and lubricant samples by mechanic workers was found equal to 1.2 mSv y(-1) cm(-2).

  9. POC export from ocean surface waters by means of 234Th/ 238U and 210Po/ 210Pb disequilibria: A review of the use of two radiotracer pairs

    Science.gov (United States)

    Verdeny, Elisabet; Masqué, Pere; Garcia-Orellana, Jordi; Hanfland, Claudia; Kirk Cochran, J.; Stewart, Gillian M.

    2009-08-01

    234Th ( T1/2=24.1 d) and 210Po ( T1/2=138.4 d) are particle reactive radioisotopes that are used as tracers for particle cycling in the upper ocean. Particulate organic carbon (POC) export has frequently been estimated using 234Th/ 238U disequilibrium. Recent evidence suggests that 210Po/ 210Pb disequilibrium may be used as an additional tool to examine particle export, given the direct biological uptake of 210Po into cellular material. Differences in these two radioisotope pairs with regard to their half-lives, particle reactivity and scavenging affinity in seawater should provide complementary information to be obtained on the processes occurring in the water column. Here, we review eight different studies that have simultaneously used both approaches to estimate POC export fluxes from the surface ocean. Our aim is to provide a complete "dataset" of all the existing POC flux data derived from the coupled use of both 234Th and 210Po and to evaluate the advantages and limitations of each tracer pair. Our analysis suggests that the simultaneous use of both radiotracers provides more useful comparative data than can be derived from the use of a single tracer alone. The difference in half-lives of 234Th and 210Po enables the study of export production rates over different time scales. In addition, their different biogeochemical behaviour and preferred affinity for specific types of particles leads to the conclusion that 234Th is a better tracer of total mass flux, whereas 210Po tracks POC export more specifically. The synthesis presented here is also intended to provide a basis for planning future sampling strategies and promoting further work in this field to help reveal the more specific application of each tracer under specific water column biogeochemistries.

  10. Extensive radioactive characterization of a phosphogypsum stack in SW Spain: 226Ra, 238U, 210Po concentrations and 222Rn exhalation rate.

    Science.gov (United States)

    Abril, José-María; García-Tenorio, Rafael; Manjón, Guillermo

    2009-05-30

    Phosphogypsum (PG) is a by-product of the phosphate fertilizer industries that contains relatively high concentrations of uranium series radionuclides. The US-EPA regulates the agriculture use of PG, attending to its (226)Ra content and to the (222)Rn exhalation rate from inactive stacks. Measurements of (222)Rn exhalation rates in PG stacks typically show a large and still poorly understood spatial and temporal variability, and the published data are scarce. This work studies an inactive PG stack in SW Spain of about 0.5 km(2) from where PG can be extracted for agriculture uses, and an agriculture soil 75 km apart, being representative of the farms to be amended with PG. Activity concentrations of (226)Ra, (238)U and (210)Po have been measured in 30 PG samples (0-90 cm horizon) allowing for the construction of maps with spatial distributions in the PG stack and for the characterization of the associated PG inputs to agriculture soils. Averaged (226)Ra concentrations for the stack were 730+/-60 Bq kg(-1) (d.w.), over the US-EPA limit of 370 Bq kg(-1). (222)Rn exhalation rate has been measured by the charcoal canister method in 49 sampling points with 3 canisters per sampling point. Values in PG stack were under the US-EPA limit of 2600 Bq m(-2)h(-1), but they were one order of magnitude higher than those found in the agriculture soil. Variability in radon emissions has been studied at different spatial scales. Radon exhalation rates were correlated with (226)Ra concentrations and daily potential evapotranspiration (ETo). They increased with ETo in agriculture soils, but showed an opposite behaviour in the PG stack.

  11. Energy dependence of fission product yields from 235U, 238U, and 239Pu with monoenergetic neutrons between thermal and 14.8 MeV

    Science.gov (United States)

    Gooden, Matthew; Arnold, Charles; Bhike, Megha; Bredeweg, Todd; Fowler, Malcolm; Krishichayan; Tonchev, Anton; Tornow, Werner; Stoyer, Mark; Vieira, David; Wilhelmy, Jerry

    2017-09-01

    Under a joint collaboration between TUNL-LANL-LLNL, a set of absolute fission product yield measurements has been performed. The energy dependence of a number of cumulative fission product yields (FPY) have been measured using quasi-monoenergetic neutron beams for three actinide targets, 235U, 238U and 239Pu, between 0.5 and 14.8 MeV. The FPYs were measured by a combination of fission counting using specially designed dual-fission chambers and γ-ray counting. Each dual-fission chamber is a back-to-back ionization chamber encasing an activation target in the center with thin deposits of the same target isotope in each chamber. This method allows for the direct measurement of the total number of fissions in the activation target with no reference to the fission cross-section, thus reducing uncertainties. γ-ray counting of the activation target was performed on well-shielded HPGe detectors over a period of two months post irradiation to properly identify fission products. Reported are absolute cumulative fission product yields for incident neutron energies of 0.5, 1.37, 2.4, 3.6, 4.6, 5.5, 7.5, 8.9 and 14.8 MeV. Preliminary results from thermal irradiations at the MIT research reactor will also be presented and compared to present data and evaluations. This work was performed under the auspices of the U.S. Department of Energy by Los Alamos National Security, LLC under contract DE-AC52-06NA25396, Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344 and by Duke University and Triangle Universities Nuclear Laboratory through NNSA Stewardship Science Academic Alliance grant No. DE-FG52-09NA29465, DE-FG52-09NA29448 and Office of Nuclear Physics Grant No. DE-FG02-97ER41033.

  12. Evolution of groundwater chemistry in coastal aquifers of the south-eastern White Sea area (NW Russia) using14C and234U-238U dating.

    Science.gov (United States)

    Malov, A I

    2018-03-01

    The specific objectives of the study are to clarify the sources and characteristics of groundwater in the aquifers along the coast of the White Sea in northwestern Russia, and on this basis to perform a broad 14 C and 234 U/ 238 U dating of all their types, taking into account the mixing processes. Investigation of an evolution of the groundwater chemistry revealed that the main evolutionary trends are the following: (1) Mixing Late Pleistocene brackish water end member (brackish1) and Mikulino seawater end member with strongly brackish and salty water in the Vpd aquifer (salty Vpd) formation. Groundwater dating showed the "brackish1" residence time in the aquifer of 32.96±2.3ka. Recharge of "brackish1" could have occurred in MIS 3. (2) Mixing Late Pleistocene freshwater end member (fresh LP) and "salty Vpd" end member with brackish water (brackish2) formation. Groundwater dating showed the "brackish2" residence time in the aquifer from 25.1±0.7 to 39.2±6.3ka. Recharge of "fresh LP" could have occurred ~ in MIS 3 also. (3) Mixing Middle Pleistocene-Holocene freshwater of melting glaciers (fresh MP-H) end member and brine end member with the strongly brackish and salty water in Vmz aquifer (salty Vmz) formation. Recharge of "fresh MP-H" could have occurred in Middle Pleistocene-Holocene during MIS 12-MIS 1. As a result of intensive and rapid recharge after the glacial melting, glacial fluids have penetrated at depth to >200m. The results of this study provide a better understanding of the interrelationship of various groundwater flows near the coasts and contribute to a more justified and efficient use of them for drinking water supply in large cities, balneological treatment and industrial extraction of iodine waters. They also allow assessment of the risks of dumping saline drainage water into the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Tumor necrosis factor-α -308G/A and -238G/A polymorphisms are associated with increased risks of sepsis: evidence from an updated meta-analysis.

    Science.gov (United States)

    Zhang, Mu; Zhao, Yu; Liu, Qiong

    2017-05-01

    Previous studies have reported the relationship between tumor necrosis factor-α (TNF-α) -308G/A and -238G/A polymorphisms and sepsis risk with inconsistent results. The aim of this study was to estimate the association of the two polymorphisms with risk of sepsis or sepsis-related mortality using a meta-analysis. PubMed, Embase, and Web of Science databases were searched up to June 20 2016. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed or random effect model. Twenty-six studies were included in this meta-analysis. Overall, an increased sepsis risk of TNF-α -308G/A was observed (GA vs GG: OR = 1.43, 95% CI: 1.07-1.92; GA/AA vs GG: OR = 1.42, 95% CI: 1.06-1.89). Subgroup analyses showed that the significant association was found in Asians (GA vs GG: OR = 1.63, 95% CI: 1.01-2.63) and adult patients. Similarly, an increased sepsis risk of TNF-α -238G/A was observed in overall and subgroup analyses. However, no significant association was found between TNF-α -308G/A and -238G/A polymorphisms and sepsis-related mortality. These findings indicate that both TNF-α -308G/A and -238G/A polymorphisms were associated with increased risks of sepsis but not sepsis-related mortality. Further studies with larger sample size are needed to confirm these results. © 2017 APMIS. Published by John Wiley & Sons Ltd.

  14. Photofission cross-section ratio measurement of {sup 235}U/{sup 238}U using monoenergetic photons in the energy range of 9.0–16.6 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Krishichayan, E-mail: krishi@tunl.duke.edu [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Bhike, Megha; Finch, S.W.; Howell, C.R. [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Tonchev, A.P. [Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Tornow, W. [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States)

    2017-05-11

    Photofission cross-section ratios of {sup 235}U and {sup 238}U have been measured using monoenergetic photon beams at the HIγS facility of TUNL. These measurements have been performed in small energy steps between 9.0 and 16.6 MeV using a dual-fission ionization chamber. Measured cross-section ratios are compared with the previous experimental data as well as with the recent evaluated nuclear data library ENDF.

  15. Experimental Cross Sections for Reactions of Heavy Ions and 208Pb, 209Bi, 238U, and 248Cm Targets

    Energy Technology Data Exchange (ETDEWEB)

    Patin, Joshua Barnes [Univ. of California, Berkeley, CA (United States)

    2002-01-01

    The study of the reactions between heavy ions and 208Pb, 209Bi, 238U, and 248Cm Cm targets was performed to look at the differences between the cross sections of hot and cold fusion reactions. Experimental cross sections were compared with predictions from statistical computer codes to evaluate the effectiveness of the computer code in predicting production cross sections. Hot fusion reactions were studied with the MG system, catcher foil techniques and the Berkeley Gas-filled Separator (BGS). 3n- and 4n-exit channel production cross sections were obtained for the 238U(18O,xn)256-xFm, 238U(22Ne,xn)260-xNo, and 248Cm(15N,xn)263-xLr reactions and are similar to previous experimental results. The experimental cross sections were accurately modeled by the predictions of the HIVAP code using the Reisdorf and Schaedel parameters and are consistent with the existing systematics of 4n exit channel reaction products. Cold fusion reactions were examined using the BGS. The 48Pb(238Ca,xn)256-xNo, 208Pb(50Ti,xn)258-xRf, 208Pb(51V,xn)259-xDb, 50Bi(238Ti,xn)259-xDb, and 209Bi(51V,xn)260-xSg reactions were studied. The experimental production cross sections are in agreement with the results observed in previous experiments. It was necessary to slightly alter the Reisdorf and Schaedel parameters for use in the HIVAP code in order to more accurately model the experimental data. The cold fusion experimental results are in agreement with current 1n- and 2n-exit channel systematics.

  16. INFRACŢIUNILE PREVĂZUTE LA ART.238 ŞI 239 CP RM ÎN LUMINA AMENDAMENTELOR OPERATE ÎN CODUL PENAL LA 25.07.2014

    Directory of Open Access Journals (Sweden)

    Vitalie STATI

    2015-11-01

    Full Text Available Prezentul articol este consacrat analizei de drept penal a infracţiunilor prevăzute la art.238 şi 239 CP RM. Analiza este efectuată prin prisma Legii pentru modificarea şi completarea unor acte legislative din 25.07.2014. În acord cu aceasta, aria de aplicare a art.238 CP RM a fost extinsă asupra ipotezelor presupunând prezentarea cu bună ştiinţă a unor infor-maţii false în scopul obţinerii unui împrumut sau a unei despăgubiri/indemnizaţii de asigurare, ori al majorării sumei acestora, ori al obţinerii unui împrumut în condiţii avantajoase, dacă prin aceasta instituţiei financiare, organizaţiei financiare nebancare, asociaţiei de economii şi împrumut sau asigurătorului i-au fost cauzate daune. De asemenea, art.238 CP RM a fost completat cu alineatul (2: „Aceleaşi acţiuni care au cauzat daune în proporţii deosebit de mari”. Nu în ultimul rând, aria de aplicare a art.239 CP RM a fost extinsă asupra ipotezelor presupunând acordarea unui împru-mut sau a unei despăgubiri/indemnizaţii de asigurare cu încălcarea intenţionată a legii, a politicilor de acordare a împru-muturilor sau normelor de prudenţă financiară, dacă prin aceasta instituţiei financiare, organizaţiei financiare nebancare, asociaţiei de economii şi împrumut sau asigurătorului i-au fost cauzate daune.THE OFFENCES REFFERED TO AT ART.238 AND 239 PC RM IN THE LIGHT OF THE AMENDMENTS OPERATED TO THE PENAL CODE AT 07.25.2014This article is dedicated to the penal law analysis of the offences referred to at art.238 and 239 PC RM. The analysis is carried through the Law on amending and supplementing certain legislative acts from 25.07.2014. In line with these procedures, the application scope of art.238 PC RM was extended over the hypothesis assuming knowingly presenting false information in order to obtain a loan or reparation/insurance claim, or to increase their amount, or to obtain a loan on favorable terms, if all these were caused

  17. Assessment of natural radionuclides concentration from {sup 238}U and {sup 232}Th series in Virginia and Burley varieties of Nicotiana tabacum L; Avaliacao da concentracao dos radionuclideos naturais das series do {sup 238}U e {sup 232}Th nas variedades Burley e Virginia da Nicotiana tabacum L.

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Carolina Fernanda da

    2015-07-01

    Brazil is the largest exporter and second largest producer of tobacco worldwide, according to the crop production of 2013/2014. The tobacco plant (Nicotiana tabacum L.) is used to manufacture all derivatives and the chemical composition of the resulting tobacco products varies with the type of tobacco leaves, how they are grown, the region where they are cultivated, the characteristics of preparation (compression, filter and paper) and the temperature variations resulting from the incomplete combustion of tobacco. Tobacco products are extensively used throughout the world, and the most consumed are cigarettes, cigars and narghile. The damaging effects that these products cause to human health are discussed globally, and many surveys are performed with the aim of relating the use of these products with various illnesses. There is a lack of information about the radiological characterization of the tobacco plant both in international and Brazilian literature. The objective of this study was to determine the concentration of radionuclides {sup 238}U, {sup 234}U, {sup 230}Th, {sup 22}'6Ra, {sup 210}Pb and {sup 210}Po, members from the {sup 238}U decay series, and the radionuclides {sup 232}Th and {sup 228}Ra members of the {sup 232}Th decay series in the varieties Burley and Virginia, which are the most cultivated in Brazil. Plants from these varieties were cultivated in pots with organic substrate and fertilizer and also acquired from the producers and analyzed by alpha spectrometry for U and Th isotopes and {sup 210}Po determination, and gross alpha and beta counting, {sup 228}Ra, {sup 226}Ra and {sup 210}Pb determination. The whole plant, from both places, was analyzed; root, stem, leaves, as well as the organic substrate, the fertilizers, and the soil. The results for U and Th isotopes presented values below the detection limits of the methods to the leaves and stems of all plants analyzed, with measurable results only in roots, soil, and substrate. The

  18. Crystallisation ages in coeval silicic magma bodies: 238U-230Th disequilibrium evidence from the Rotoiti and earthquake flat eruption deposits, Taupo volcanic zone, New Zealand

    Science.gov (United States)

    Charlier, B.L.A.; Peate, D.W.; Wilson, C.J.N.; Lowenstern, J. B.; Storey, M.; Brown, S.J.A.

    2003-01-01

    The timescales over which moderate to large bodies of silicic magma are generated and stored are addressed here by studies of two geographically adjacent, successive eruption deposits in the Taupo Volcanic Zone, New Zealand. The earlier, caldera-forming Rotoiti eruption (>100 km3 magma) at Okataina volcano was followed, within months at most, by the Earthquake Flat eruption (??? 10 km3 magma) from nearby Kapenga volcano; both generated nonwelded ignimbrite and coeval widespread fall deposits. The Rotoiti and Earthquake Flat deposits are both crystal-rich high-silica rhyolites, with sparse glass-bearing granitoid fragments also occurring in Rotoiti lag breccias generated during caldera collapse. Here we report 238U-230Th disequilibrium data on whole rocks and mineral separates from representative Rotoiti and Earthquake Flat pumices and the co-eruptive Rotoiti granitoid fragments using TIMS and in situ zircon analyses by SIMS. Multiple-grain zircon-controlled crystallisation ages measured by TIMS from the Rotoiti pumice range from 69??3 ka ( 350 ka, with a pronounced peak at 70-90 ka. The weighted mean of isochrons is 83??14 ka, in accord with the TIMS data. One glass-bearing Rotoiti granitoid clast yielded an age of 57??8 ka by TIMS (controlled by Th-rich phases that, however, are not apparently present in the juvenile pumices). Another glass-bearing Rotoiti granitoid yielded SIMS zircon model ages peaking at 60-90 ka, having a similar age distribution to the pumice. Age data from pumices are consistent with a published 64??4 ka eruptive age (now modified to 62??2 ka), but chemical and/or mineralogical data imply that the granitoid lithics are not largely crystalline Rotoiti rhyolite, but instead represent contemporaneous partly molten intrusions reflecting different sources in their chemistries and mineralogies. Similarly, although the Earthquake Flat eruption immediately followed (and probably was triggered by) the Rotoiti event, age data from juvenile material

  19. Eruption and magma crystallization ages of Las Tres Vírgenes (Baja California) constrained by combined 230Th/ 238U and (U-Th)/He dating of zircon

    Science.gov (United States)

    Schmitt, Axel K.; Stockli, Daniel F.; Hausback, Brian P.

    2006-11-01

    Las Tres Vírgenes volcano is a calc-alkaline composite cone located near the main Gulf of California escarpment on the E coast of the Baja California peninsula. High-sensitivity ion microprobe U-series ( 230Th/ 238U) ages for zircon from La Vírgen tephra average 121 - 10 + 12 ka (1σ; MSWD = 2.7), with discrete age peaks at ˜ 100 and 160 ka. The noble gas mass spectrometric (U-Th)/He zircon age, corrected for disequilibrium and pre-eruptive storage, is 36 ± 3 ka. This result for the eruption age of La Vírgen tephra is significantly older than previously postulated historic or Holocene ages that were based on an 18th century map reference and 14C dating of accidental charcoal, respectively. The new (U-Th)/He zircon age is consistent with a > 26 ± 4 ka age derived from cosmogenic He exposure dating of an overlying basaltic lava flow [Hausback, B.P. and Abrams, M.J., 1996. Plinian eruption of La Virgen Tephra, Volcán Las Tres Virgenes, Baja California Sur, Mexico. Eos, Transactions, American Geophysical Union, 77(46, Suppl.): 813-814.]. U-Pb zircon analysis of ignimbrites erupted from the adjacent Early Pleistocene La Reforma and El Aguajito calderas yielded ages of 1.38 ± 0.03 Ma ( n = 12; MSWD = 1.0) and 1.17 ± 0.07 Ma ( n = 23; MSWD = 1.3), respectively. No evidence for these ages is found among La Vírgen zircons, whereas pre-Quaternary zircon xenocrysts are common. The La Vírgen magma, therefore, evolved unrelated to Early Pleistocene magmatism in adjacent calderas, but assimilated local basement rocks. A gap between average Th-U and (U-Th)/He zircon ages suggests that zircon crystallization was discontinuous in the La Vírgen magma chamber. In addition, partial resorption of zircon suggests episodic thermal rejuvenation, most likely by basaltic recharge. Based on the zircon record, the > 100 ka lifetime of the thermal anomaly that sustained repeated intrusive pulses significantly exceeds the age of the last eruption. This strengthens the view that Tres

  20. CREATING THE KULTUK POLYGON FOR EARTHQUAKE PREDICTION: VARIATIONS OF (234U/238U AND 87SR/86SR IN GROUNDWATER FROM ACTIVE FAULTS AT THE WESTERN SHORE OF LAKE BAIKAL

    Directory of Open Access Journals (Sweden)

    S. V. Rasskazov

    2015-01-01

    Full Text Available Introduction. Determinations of (234U/238U in groundwater samples are used for monitoring current deformations in active faults (parentheses denote activity ratio units. The cyclic equilibrium of activity ratio 234U/238U≈≈(234U/238U≈γ≈1 corresponds to the atomic ratio ≈5.47×10–5. This parameter may vary due to higher contents of 234U nuclide in groundwater as a result of rock deformation. This effect discovered by P.I. Chalov and V.V. Cherdyntsev was described in [Cherdyntsev, 1969, 1973; Chalov, 1975; Chalov et al., 1990; Faure, 1989]. In 1970s and 1980s, only quite laborious methods were available for measuring uranium isotopic ratios. Today it is possible to determine concentrations and isotopic ration of uranium by express analytical techniques using inductively coupled plasma mass spectrometry (ICP‐MS [Halicz et al., 2000; Shen et al., 2002; Cizdziel et al., 2005; Chebykin et al., 2007]. Sets of samples canbe efficiently analysed by ICP‐MS, and regularly collected uranium isotope values can be systematized at a new quality level for the purposes of earthquake prediction. In this study of (234U/238U in groundwater at the Kultuk polygon, we selected stations of the highest sensitivity, which can ensure proper monitoring of the tectonic activity of the Obruchev and Main Sayan faults. These two faults that limit the Sharyzhalgai block of the crystalline basement of the Siberian craton in the south are conjugated in the territory of the Kultuk polygon (Fig 1. Forty sets of samples taken from 27 June 2012 to 28 January 2014 were analysed, and data on 170 samples are discussed in this paper.Methods. Isotope compositions of uranium and strontium were determined by methods described in [Chebykin et al., 2007; Pin et al., 1992] with modifications. Analyses of uranium by ISP‐MS technique were performed using an Agilent 7500ce quadrapole mass spectrometer of the Ultramicroanalysis Collective Use Centre; analyses of

  1. Correlation of the activity of the {sup 238} U in soil and {sup 222} Rn in domiciles, with the rocks of cities of the Estado de Chihuahua; Correlacion de la actividad del {sup 238} U en suelo y {sup 222} Rn en domicilios, con las rocas de ciudades del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero S, L.; Villalba, L.; Montero C, M.E. [Centro de Investigacion en Materiales Avanzados (CIMAV), Av. Miguel de Cervantes 120 C.P. 31109 Chihuahua (Mexico)]. e-mail: luis.colmenero@cimav.edu.mx

    2004-07-01

    The state of Chihuahua has numerous locations of uranium, being Pena Blanca the great and more important location of the country. Diverse rock types with important quantities of uranium are distributed by the whole state. The igneous extrusive acid rocks are those that have bigger quantity of uranium, like they are the rhyolites and dacites and these rocks are located in enough proportion by the whole state. Some of the main cities of the state are near to locations or uraniferous rocks, as Aldama, Nuevo Casas Grandes, Chihuahua, Jimenez and Bocoyna, other important cities are not near important locations. It was determined specific activity by gamma spectroscopy of the series of the {sup 238} U in soils and determination of the radon concentration in domiciles of the main cities of the state. They were found high specific activity values in soil in eight of the thirteen analyzed cities and important radon concentrations in three cities. It was found relationship among the specific activity in soil in near cities to uraniferous locations. (Author)

  2. Origin and geochemical behavior of uranium in marine sediments. Utilization of the {sup 234}U/{sup 238}U ratio in marine geochemistry; Origine et comportement geochimique de l`uranium dans les sediments marins. Utilisation du rapport ({sup 234}U/{sup 238}U) en geochimie marine

    Energy Technology Data Exchange (ETDEWEB)

    Organo, Catherine [Paris-11 Univ., 91 - Orsay (France)

    1997-01-20

    The first part of this thesis presents the current situation of knowledge of uranium in marine environment. The second part describes the methods of analysis as well as the material support of the study, i.e., the sediments and marine deposits investigated. The third part is dedicated to the study of uranium mobility in marine sediments characterized by detrital terrigenous composition (pelagic clays). This approach allowed quantifying the entering and leaving flux of uranium after the sediment settling and, to discuss, on this basis, the consequences on the uranium oceanic balance. In the third part the origin and behavior of uranium in zones of high surface productivity is studied. The uranium enrichments observed in the hemi-pelagic sediments of the EUMELI (J.G.O.F.S.-France) programme will constitute a material of study adequate for measuring the variations in the {sup 234}U/2{sup 38U} ratio in solid phase, in response to the oxido-reducing characteristics of the sediment. Thus establishing the origin of the trapped uranium has been possible. Also, the nature of the sedimentary phases related to uranium in bio-genetic sediments in the Austral Ocean was determined. Thus a relationship between the variations in the {sup 234}U/{sup 238} and the diagenetic transformations was possible to establish. Finally in the fifth part a study of the behavior of uranium in a polymetallic shell characteristic for deposits of hydrogenized origin 146 refs., 57 figs., 23 tabs.

  3. Improved 206Pb/238U microprobe geochronology by the monitoring of a trace-element-related matrix effect; SHRIMP, ID-TIMS, ELA-ICP-MS and oxygen isotope documentation for a series of zircon standards

    Science.gov (United States)

    Black, L.P.; Kamo, S.L.; Allen, C.M.; Davis, D.W.; Aleinikoff, J.N.; Valley, J.W.; Mundil, R.; Campbell, I.H.; Korsch, R.J.; Williams, I.S.; Foudoulis, C.

    2004-01-01

    Precise isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) documentation is given for two new Palaeozoic zircon standards (TEMORA 2 and R33). These data, in combination with results for previously documented standards (AS3, SL13, QGNG and TEMORA 1), provide the basis for a detailed investigation of inconsistencies in 206Pb/238U ages measured by microprobe. Although these ages are normally consistent between any two standards, their relative age offsets are often different from those established by ID-TIMS. This is true for both sensitive high-resolution ion-microprobe (SHRIMP) and excimer laser ablation-inductively coupled plasma-mass spectrometry (ELA-ICP-MS) dating, although the age offsets are in the opposite sense for the two techniques. Various factors have been investigated for possible correlations with age bias, in an attempt to resolve why the accuracy of the method is worse than the indicated precision. Crystallographic orientation, position on the grain-mount and oxygen isotopic composition are unrelated to the bias. There are, however, striking correlations between the 206Pb/238U age offsets and P, Sm and, most particularly, Nd abundances in the zircons. Although these are not believed to be the primary cause of this apparent matrix effect, they indicate that ionisation of 206Pb/238U is influenced, at least in part, by a combination of trace elements. Nd is sufficiently representative of the controlling trace elements that it provides a quantitative means of correcting for the microprobe age bias. This approach has the potential to reduce age biases associated with different techniques, different instrumentation and different standards within and between laboratories. Crown Copyright ?? 2004 Published by Elsevier B.V. All rights reserved.

  4. Angular distributions of target fragments from the reactions of 292 MeV - 25. 2 GeV /sup 12/C with /sup 197/Au and /sup 238/U

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Y.

    1983-05-20

    Angular distributions of target fragments from the reactions of /sup 12/C with /sup 197/Au and /sup 238/U were measured at projectile energies of 292 MeV, 1.0 GeV, 3.0 GeV, 12.0 GeV and 25.2 GeV. The angular distributions of the /sup 197/Au target fragments were all forwardly peaked. Extensively forward peaked angular distributions were observed at the non-relativistic projectile energies (292 MeV, 1.0 GeV). No obvious differences were observed in the angular distributions at the different relativistic projectile energies of 3.0 GeV, 12.0 GeV and 25.2 GeV. The characteristic angular distribution pattern from the relativistic projectile energy experiments was also observed in the non-relativistic energy experiments. Maximum degree of forward-peaking in the angular distributions at each projectile energy was observed at the product mass number (A) around 190 from the 292 MeV projectile energy, at A=180 from 1.0 GeV and at A=175 from 3.0 GeV and 12.0 GeV. In general, two different types of angular distributions were observed in the relativistic projectile energy experiments with the /sup 238/U target. Isotropic angular distributions were observed for the fission product nuclides. The angular distributions of the fission products at the intermediate (292 MeV) energy showed slightly forward- peaked angular distributions. Because of the long projectile-target interaction time in the primary nuclear reaction, larger momentum was transferred from the projectile to the target nucleus. Steep forward-peaked angular distributions were also observed with the /sup 238/U target.

  5. Neutron capture cross section measurement of 238U at the CERN n_TOF facility in the energy region from 1 eV to 700 keV

    Science.gov (United States)

    Mingrone, F.; Massimi, C.; Vannini, G.; Colonna, N.; Gunsing, F.; Žugec, P.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brugger, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Cortés, G.; Cortés-Giraldo, M. A.; Diakaki, M.; Domingo-Pardo, C.; Duran, I.; Dressler, R.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A. R.; Giubrone, G.; Gonçalves, I. F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Hernández-Prieto, A.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Kokkoris, M.; Krtička, M.; Kroll, J.; Lampoudis, C.; Langer, C.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Leong, L. S.; Lo Meo, S.; Losito, R.; Mallick, A.; Manousos, A.; Marganiec, J.; Martínez, T.; Mastinu, P. F.; Mastromarco, M.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mirea, M.; Mondalaers, W.; Paradela, C.; Pavlik, A.; Perkowski, J.; Plompen, A.; Praena, J.; Quesada, J. M.; Rauscher, T.; Reifarth, R.; Riego, A.; Robles, M. S.; Rubbia, C.; Sabaté-Gilarte, M.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Tagliente, G.; Tain, J. L.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Variale, V.; Vaz, P.; Ventura, A.; Vermeulen, M. J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T.; n TOF Collaboration

    2017-03-01

    The aim of this work is to provide a precise and accurate measurement of the 238U(n ,γ ) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behavior of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross section of 238U should be further reduced to 1-3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the n_TOF facility, were proposed and carried out within the 7th Framework Project ANDES of the European Commission. The results of one of these 238U(n ,γ ) measurements performed at the n_TOF CERN facility are presented in this work. The γ -ray cascade following the radiative neutron capture has been detected exploiting a setup of two C6D6 liquid scintillators. Resonance parameters obtained from this work are on average in excellent agreement with the ones reported in evaluated libraries. In the unresolved resonance region, this work yields a cross section in agreement with evaluated libraries up to 80 keV, while for higher energies our results are significantly higher.

  6. 187Re - 232Th - 238U nuclear geochronometry: constraining magmatism in East-Antarctica and the break-up of Gondwana

    Science.gov (United States)

    Roller, Goetz

    2017-04-01

    187Re - 232Th - 238U nuclear geochronometry is a new dating method for astronomy, earth and planetary sciences [1-4]. Nucleogeochronometric Rhenium-Osmium two-point-isochron (TPI) ages are calculated using a nuclear geochronometer as one data point in a two-point-isochron diagram [5-7]. The IVREA chronometer, for example, is one of five terrestrial nuclear geochronometers identified so far [8]. Here, it is used to constrain the magmatism of the Ferrar flood basalt province, which has been related to continental rifting and the break-up of Gondwana in the Jurassic.TPI ages for seven (basaltic) andesite whole rock samples from the Prince Albert Mountains (Victoria Land, Antarctica) are calculated. An isochron age of 172 ± 5 Ma (187Os/188Osi = 0.194 ± 0.023) has previously been published for these rocks [9]. Initial TPI 187Os/188Osi ratios show only minor scatter between 187Os/188Osi = 0.2149 ± 0.0064 and 187Os/188Osi = 0.22231 ± 0.00080, in agreement with the enigmatic, suprachondritic 187Os/188Osi = 0.194 ± 0.023 from the isochron [9]. TPI ages for the Mount Joyce samples range from 125.4 ± 9.9 Ma to 139 ± 17 Ma and thus constrain the youngest magmatic event(s) in the Transantarctic Mountains. For the Thumb Point basalt, a TPI age of 219 ± 81 Ma is calculated. Despite of its large uncertainty, the age itself is in agreement with the Triassic 224 Ma and 240 Ma events reported from North Patagonia [10]. The TPI age of 186.1 ± 8.1 Ma from the Ricker Hill basalt can be clearly distinguished from the Mount Murray TPI age of 158 ± 14 Ma, while at Brimstone Peak two TPI age groups of 155 ± 14 Ma and 175.3 ± 3.1 Ma are observed. From this it may be concluded that the seven TPI ages indicate episodic magmatic activity in East-Antarctica between 125 Ma and 219 Ma, leading to the break-up of Gondwana. This picture is consistent with the geochronology of the Antarctic Peninsula, Patagonia, the Karoo and the Ferrar mafic rocks [10]. Thus, besides constraining

  7. Mass measurements of {sup 238}U-projectile fragments for the first time with a multiple-reflection time-of-flight mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Jens

    2016-07-01

    Mass measurements of short-lived uranium projectile fragments were performed for the first time with a Multiple-Reflexion-Time-of-Flight Mass Spectrometer (MR-TOF-MS). A major part of this doctoral work was a novel development of a data analysis method for the MR-TOF-MS mass measurements of exotic nuclei at the fragment separator FRS at GSI. The developed method was successfully applied to the data obtained from two pilot experiments with the MR-TOF-MS at the FRS in 2012 and 2014. A substantial upgrade of the experimental setup of the MR-TOF-MS was also performed in the frame work of this doctoral thesis after the first run. In the experiments projectile fragments were created with 1000 MeV/u {sup 238}U ions in a Be/Nb target at the entrance of the in-flight separator FRS. The exotic nuclei were spatially separated, energy bunched and slowed down with the ion-optical system of the FRS combined with monoenergetic and homogeneous degraders. At the final focal plane of the FRS the fragments were completely slowed down and thermalized in a cryogenic stopping cell (CSC) filled with 3-5 mg/cm{sup 2} pure helium gas. The exotic nuclei were fast extracted from the CSC to enable mass measurements of very short-lived fragments with the MR-TOF-MS. The achievement of this goal was successfully demonstrated with the mass measurement of {sup 220}Ra ions with a half-life of 17.9 ms and 11 detected events. The mass measurements of the isobars {sup 211}Fr, {sup 211}Po and {sup 211}Rn have clearly demonstrated the scientific potential of the MR-TOF-MS for the investigation of exotic nuclei and the power of the data analysis system. Difficult measurements with overlapping mass distributions with only a few counts in the measured spectra were the challenge for the new data analysis method based on the maximum likelihood method. The drifts during the measurements were corrected with the developed time-resolved calibration method. After the improvements of the setup as a consequence of

  8. Evaluación de las dimensiones de valencia, activación, frecuencia subjetiva de uso y relevancia para la ansiedad, la depresión y la ira de 238 sustantivos en una muestra universitaria

    Directory of Open Access Journals (Sweden)

    Alberto Acosta

    2010-01-01

    Full Text Available Se presentan los resultados de las evaluaciones que realizaron un grupo de estudiantes universitarios sobre 238 sustantivos en las dimensiones de valencia, activación, frecuencia subjetiva de uso y relevancia para la ansiedad, la depresión y la ira. Los datos normativos que se muestran pueden ser de gran utilidad para aquellos investigadores que estudian las relaciones entre cognición y emoción, particularmente cuando utilizan tareas de atención o de memoria en que se incluyen estímulos verbales y los participantes son seleccionados por sus rasgos afectivos.

  9. Measurement of the 238U neutron-capture cross section and gamma-emission spectra from 10 eV to 100 keV using the DANCE detector at LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Ullmann, John L [Los Alamos National Laboratory; Couture, A J [Los Alamos National Laboratory; Keksis, A L [Los Alamos National Laboratory; Vieira, D J [Los Alamos National Laboratory; O' Donnell, J M [Los Alamos National Laboratory; Jandel, M [Los Alamos National Laboratory; Haight, R C [Los Alamos National Laboratory; Rundberg, R S [Los Alamos National Laboratory; Kawano, T [Los Alamos National Laboratory; Chyzh, A [NORTH CAROLINA STATE UNIV; Baramsai, B [NORTH CAROLINA STATE UNIV; Wu, C Y [LLNL; Mitchell, G E [NORTH CAROLINA STATE UNIV; Becker, J A [LLNL; Krticka, M [CHARLES UNIV

    2010-01-01

    A careful new measurement of the {sup 238}U(n,{gamma}) cross section from 10 eV to 100 keV has been made using the DANCE detector at LANSCE. DANCE is a 4{pi} calorimetric scintillator array consisting of 160 BaF{sub 2} crystals. Measurements were made on a 48 mg/cm{sup 2} depleted uranium target. The cross sections are in general good agreement with previous measurements. The gamma-ray emission spectra, as a function of gamma multiplicity, were also measured and compared to model calculations.

  10. Measurement of neutron-induced fission cross-sections of Th232, U238, U233 and Np237 relative to U235 from 1 MeV to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Shcherbakov, O.A.; Laptev, A.B.; Petrov, G.A. [Petersburg Nuclear Physics Inst., Gatchina, Leningrad district (Russian Federation); Fomichev, A.V.; Donets, A.Y.; Osetrov, O.I.

    1998-11-01

    The measurements of neutron-induced cross-section ratios for Th232, U238, U233 and Np237 relative to U235 have been carried out in the energy range from 1 MeV up to 200 MeV using the neutron time-of-flight spectrometer GNEIS based on 1 GeV proton synchrocyclotron. Below 20 MeV, the results of present measurements are roughly in agreement with evaluated data though there are some discrepances to be resolved. (author)

  11. Determination of uranium isotopes ({sup 235}U, {sup 238}U) and trace elements (Cd, Pb, Cu and As) in bottled drinking water by Icp-SFMS; Determinacion de isotopos de uranio ({sup 235}U, {sup 238}U) y elementos traza (Cd, Pb, Cu y As) en agua embotellada para beber por ICP-SFMS

    Energy Technology Data Exchange (ETDEWEB)

    Lara A, N.; Hernandez M, H.; Romero G, E. T.; Kuri de la C, A.; Perez B, M. A., E-mail: nancy.lara@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2016-09-15

    In the present work we propose an optimized method for the quantification of uranium isotopes ({sup 235}U, 2{sup 38}U) and the elements Cd, Pb, Cu and As in bottled water for drinking at trace levels of concentration. Based on the multi-element detection capability, the high sensitivity and resolution that the Mass Spectrometry with Magnetic Sector with Inductively Coupled Plasma Source (Icp-SFMS) technique offers; the high, medium and low resolution analysis conditions for the elements under study were established and optimized using and Element 2/Xr equipment and the 23 multi-elemental Certified Reference Material (CRM). The analysis method was validated using the standard reference material Nist 1643d and CRM mono-elemental s as external standards for the quantification of the analytes. Samples, targets and CRM were acidified with 2% of HNO{sub 3} and analyzed without pretreatment under the established analysis conditions. The results obtained show concentrations of {sup 235}U, {sup 238}U, {sup 111}Cd, {sup 208}Pb, {sup 63}Cu and {sup 75}As in the range of μg L{sup -1}, the linearity obtained from the calibration curves for each element has correlation coefficients < 0.99 in all cases, the accuracy of the method in terms of percent relative standard deviation (RSD %) was less than 5%, the mean recovery rate of Nist 1643d ranged from 96.46% to 101.12%. The optimization of the method guarantees the stability and calibration of the equipment throughout the analysis, as well as the ability to resolve interferences. In conclusion, the method proposed using Icp-SFMS offers the advantages of being fast and simple for the multi-elemental analysis in water at trace levels, with low limits of quantification and detection, with good linearity, accuracy, precision and reproducibility to a degree of reliability of 95%. (Author)

  12. Mass spectroscopy analysis of [sup 136]Ra and of the [sup 234]U / [sup 238]U disequilibria in natural waters: a new dating tool in hydrogeology. Analyses par spectrometrie de masse du [sup 136]Ra et des desequilibres [sup 234]U / [sup 238]U dans les eaux naturelles: un nouvel outil de datation en hydrogeologie

    Energy Technology Data Exchange (ETDEWEB)

    Joffroy, M.E.

    1997-10-27

    Physico-chemical characteristics of radium and its geochemical behaviour in underground waters remain badly known. The aim of this work is to try to determine its origins, behaviour with respect to other elements, and content in waters. After a recall of the classical techniques used for radium analysis, the thermal ionization mass spectrometry used in this study is described in details. A special method has been developed for radium extraction and separation from barium. Thanks to this technical improvement, the exchanges between the matrix and the pore water in aquifers and soils could have been studied using very small water samples. Two examples of application are presented: the small hydrologic system (soils, surface waters and springs) in the crystalline environment of the side basin of the Blackburn river in the Laurentides north of Ottawa (Canada), and the carbonated environment of the Cretaceous chalk aquifer of the Paris basin (France) with highly mineralized waters. In both examples, complementary analyses of soils and of the aquifers matrix were performed with the study of [sup 226]Ra/[sup 238]U, Ra/Ba, Ra/Ca, and Ra/Sr ratios. Different models of ground waters dating for aquifer recharge studies and using [sup 3]H, [sup 14]C and [sup 36]Cl are validated and compared with the [sup 226]Ra dating method developed in this study. The comparison between the different dating methods shows that the complexity of radium geochemistry in carbonated environment greatly limits the use of [sup 226]Ra in ground water dating and that the geochronological models are highly site-dependent. (J.S.) 226 refs.

  13. Neutron capture cross section measurement of $^{238}$U at the n_TOF CERN facility in the energy region from 1 eV to 700 keV

    CERN Document Server

    Mingrone, F; Vannini, G; Colonna, N; Gunsing, F; Zugec, P; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Becares, V; Becvavr, F; Belloni, F; Berthoumieux, E; Billowes, J; Bosnar, D; Brugger, M; Calviani, M; Calvino, F; Cano-Ott, D; Carrapico, C; Cerutti, F; Chiaveri, E; Chin, M; Cortes, G; Cortes-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; Garcia, A R; Giubrone, G; Goncalves, I F; Gonzalez-Romero, E; Griesmayer, E; Guerrero, C; Hernandez-Prieto, A; Jenkins, D G; Jericha, E; Kadi, Y; Kappeler, F; Karadimos, D; Kivel, N; Koehler, P; Kokkoris, M; Krticka, M; Kroll, J; Lampoudis, C; Langer, C; Leal-Cidoncha, E; Lederer, C; Leeb, H; Leong, L S; Lo Meo, S; Losito, R; Mallick, A; Manousos, A; Marganiec, J; Martinez, T; Mastinu, P F; Mastromarco, M; Mendoza, E; Mengoni, A; Milazzo, P M; Mirea Horia, M; Mondalaers, W; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Robles, M S; Rubbia, C; Sabate-Gilarte, M; Sarmento, R; Saxena, A; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; LTain, J; Tarrio, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Variale, V; Vaz, P; Ventura, A; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiss, C; Wright, T

    2016-01-01

    The aim of this work is to provide a precise and accurate measurement of the $^{238}$U(n,$\\gamma$) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behaviour of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross-section of $^{238}$U should be further reduced to 1-3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the n_TOF facility, were pr...

  14. Neutron capture cross section measurement of 238U at the n TOF CERN facility with C6D6 scintillation detectors in the energy region from 1 eV to 700 keV

    CERN Document Server

    Mingrone, F.

    2017-01-01

    The aim of this work is to provide a precise and accurate measurement of the 238U(n,g) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behaviour of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross-section of 238U should be further reduced to 1-3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the n_TOF facility, were proposed and carrie...

  15. A year-by-year record of 236-U/238-U in coral as a step towards establishing 236-U from nuclear weapons testing fall-out as oceanic tracer

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, Stephan; Steier, Peter [University of Vienna, Faculty of Physics, Vienna (Austria); Carilli, Jessica [Australian Nuclear Science and Technology Organisation, Lucas Heights (Australia)

    2012-07-01

    Since uranium is known to behave conservatively in ocean waters, 236-U has great potential in application as oceanic tracer. 236-U (t1/2=23.4 Ma) was introduced into the oceans by atmospheric nuclear weapon testing with amount estimates ranging from 700 kg to 1500 kg. Thus a resulting initial average 236-U/238-U ratio of at least 5e-9 is expected for an oceanic mixed layer depth of 100 m. This ratio is already higher than the natural pre-nuclear background, which is expected to be at 10e-14 levels. Even the elevated ratios of global stratospheric fall-out are beyond the capabilities of ICPMS and TIMS methods. However, the exceptional sensitivity and ultra-low background for 236-U of the Vienna Environmental Research Accelerator's Accelerator Mass Spectrometry system allows us to measure down to 10-13 detection limits. We present a year-by-year record of 236-U/238-U for a Caribbean coral core covering years 1944 to 2006, thus allowing to us put constraints on the oceanic input of 236-U by atmospheric testing. Moreover modeling of the results also demonstrates the capabilities of 236-U as oceanic tracer.

  16. Absolute photofission cross section of sup 197 Au, @Pb, sup 209 Bi, sup 232 Th, sup 238 U, and sup 235 U nuclei by 69-MeV monochromatic and polarized photons

    Energy Technology Data Exchange (ETDEWEB)

    Martins, J.B.; Moreira, E.L.; Tavares, O.A.P.; Vieira, J.L. (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq (BR) Centro Brasileiro de Pesquisas Fisicas-CBPF, Rua Dr. Xavier Sigaud 150, 22290 Rio de Janeiro-RJ, (Brazil)); Casano, L.; D' Angelo, A.; Schaerf, C. (Dipartimento di Fisica, II Universita' degli Studi di Roma Tor Vergata' ' , Via E. Carnevale, 00173 Roma, (Italy) Istituto Nazionale di Fisica Nucleare-INFN, Sezione di Roma 2, Roma, (Italy)); Terranova, M.L. (Dipartimento di Scienze e Tecnologie Chimiche, II Universita' degli Studi di Rom Torr Vergata' ' , Via E. Carnevale, 00173 Roma, (Italy) Istituto Nazionale di Fisica Nucleare-INFN, Sezione di Roma 2, Roma, Italy); Babusci, D. (Istituto Nazionale di Fisica Nucleare-INFN, Laboratori Nazionali di Frascati-LNF, Casella Postale 13, 00044 Frascati, (Italy)); Girolami, B. (Laboratorio di Fisica dell' Istituto Superiore di Sanita, Viale Regina Elena 299, 00161 Roma, (Italy) Istituto Nazionale di Fisica Nuclea

    1991-07-01

    Absolute cross-section measurements for the photofission reactions of {sup 197}Au, {sup nat}Pb, {sup 209}Bi, {sup 232}Th, {sup 238}U, and {sup 235}U nuclei have been performed at an incident photon energy of 69 MeV using monochromatic and polarized photon beams and dielectric fission-track detectors. Nuclear fissility values have been obtained and results are in agreement with those from other laboratories, although in some cases discrepancies are observed between one other. For nuclei in the region of the actinides the fissility result is {approx gt}0.4, while for Au, Pb, and Bi nuclei it only is {similar to}10{sup {minus}3}--10{sup {minus}2}. Results have been interpreted in terms of the primary Levinger's quasideuteron nuclear photoabsorption followed by a mechanism of evaporation-fission competition for the excited nuclei. Shell effects have been taken into account, and they are clearly manifested when fissility is evaluated. The influence of photon polarization on photofission of {sup 238}U also has been investigated, and results have shown isotropy in the fragment azimuthal distribution.

  17. Porosity of the melting zone and variations in the solid mantle upwelling rate beneath Hawaii: Inferences from {sup 238}U-{sup 230}Th-{sup 226}Ra and {sup 235}U-{sup 231}Pa disequilibria

    Energy Technology Data Exchange (ETDEWEB)

    Sims, K.W.W.; DePaolo, D.J.; Murrell, M.T.; Baldridge, W.S.; Goldstein, S.; Clague, D.; Jull, M.

    1999-12-01

    Measurements of {sup 238}U-{sup 230}Th-{sup 226}Ra and {sup 235}U-{sup 231}Pa disequilibria in a suite of tholeiitic-to-basanitic lavas provide estimates of porosity, solid mantle upwelling rate and melt transport times beneath Hawaii. The observation that ({sup 230}Th/{sup 238}U) {gt} 1 indicates that garnet is required as a residual phase in the magma sources for all of the lavas. Both chromatographic porous flow and dynamic melting of a garnet peridotite source can adequately explain the combined U-Th-Ra and U-Pa data for these Hawaiian basalts. For chromatographic porous flow, the calculated maximum porosity in the melting zone ranges from 0.3--3% for tholeiites and 0.1--1% for alkali basalts and basanites, and solid mantle upwelling rates range from 40 to 100 cm/yr for tholeiites and from 1 to 3 cm/yr for basanites. For dynamic melting, the escape or threshold porosity is 0.5--2% for tholeiites and 0.1--0.8% for alkali basalts and basanites, and solid mantle upwelling rates range from 10 to 30 cm/yr for tholeiites and from 0.1 to 1 cm/yr for basanites. Assuming a constant melt productivity, calculated total melt fractions range from 15% for the tholeiitic basalts to 3% for alkali basalts and basanites.

  18. Open Source: Potential in Latin America for Radiological Weapons

    Science.gov (United States)

    2010-03-01

    terrorist group would need to acquire a radioactive isotope with a relatively short half-life. 36,37 As an aside, the IAEA verified that depleted...cns.miis.edu/npr/pdfs/123salama.pdf (accessed March 3, 2010), Useful RDD isotopes include cobalt-60, strontium-90, yttrium-90, iridium-192, cesium-137...plutonium-238, radium -226, americium-241, and californium-252. 37 Hansell and Salama, “Does intent equal capability?,” 640-641. 38 Internation Atomic

  19. Study of the production of residual evaporation nuclei issued from the spallation reaction of uranium-238 by 1 GeV protons; Etude de la production de noyaux residuels d'evaporation issus de la reaction de spallation de l'uranium-238 par des protons a 1 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Taieb, J

    2000-10-01

    The spallation reaction by high energy protons is one of the envisaged nuclear reactions for production of exotic nuclei. We have measured the production of more than 300 different evaporation residues issued by the spallation reaction of Uranium-238 by 1 GeV protons. We used the reverse kinematics technique in order to produce the relativistic nuclei and therefore to be able to detect those nuclides within a very short time, shorter in most cases than the radioactive disintegration period. The achieved nuclear charge and mass resolution are excellent. They allow a good accuracy on the values of the measured cross-sections (10 to 15%). We have observed for the first time the nuclide Actinium-235 obtained consequently to the loss of 3 protons by the projectile. The measured isotopic distribution are strongly influenced by the mechanism of fission which leads to a strong reduction of the production of the heavy neutron deficient isotopes. We have compared our results to some other measurements achieved with radio-chemical methods at a similar energy. We observed a systematic disagreement of about 40%. Some comparison with the available systematics show that those are presently not able to reproduce the data with a reasonable precision. We could also measure the recoil momentum distribution for each studied isotopes. We show that Goldhaber's model agrees very well with the experiment in case. of 'cold' channels where the evaporation of particles never occurs. On the other hand, when the produced pre-fragment is excited the data show that Goldhaber's model does not reproduce.the data showing the limitation of such an approach. We finally tried to reproduce the measurement of evaporation residue cross-section thanks to the coupling of intra-nuclear cascade and statistical evaporation codes. The influence of the fission process is rather important is the system p+U; we therefore had to account for the dynamical aspect of the fission. We also showed

  20. Long-term variation (1986-1998) of post-Chernobyl 90Sr, 137Cs, 238Pu and (239,240)Pu concentrations in air, depositions to ground, resuspension factors and resuspension rates in south Germany.

    Science.gov (United States)

    Rosner, G; Winkler, R

    2001-06-12

    Annual mean concentrations in air and annual total (wet plus dry) depositions to ground of 90Sr, 137Cs, 238Pu and (239,240)Pu decreased at Neuherberg, south Germany, in the period from July 1986 (i.e. after the end of the initial deposition phase from Chernobyl) to 1998 as follows: 90Sr from 0.77 to 0.05 microBq m(-3), and from 0.82 (1988) to 0.28 Bq m(-2) year(-1); 137Cs from 133 to 2.8 microBq m(-3), and from 116 to 3.8 Bq m(-2) year(-1); 238Pu from 0.95 to 0.063 nBq m(-3), and from 1.0 to 0.23 mBq m(-2) year(-1); (239,240)Pu from 8.1 to 0.53 nBq m(-3), and from 6.4 to 2.1 mBq m(-2) year(-1). The values for the non-caesium radionuclides are compared to the few available data from other stations. After an initial phase which is characterised for a given radionuclide by the varying ratio of the Chernobyl-derived inventory to the earlier, weapons fallout-derived inventory, the time courses of concentrations of 137Cs, 90Sr, 238Pu and (239,240)Pu in air become more or less parallel (from about 1990), despite the considerable differences in the physico-chemical properties of these elements. By contrast, the time series of radionuclide deposition rates show until about 1994 less similarity among each other and with the respective concentration series in air. From 1994, concentrations in air and depositions to ground become nearly constant, or decrease very slowly. At the end of the observation period, resuspension factors between 1.4 x 10(-10) m(-1) and 1.0 x 10(-11) m(-1) are observed for the various nuclides. The time courses of specific activities (Bq g(-1)) as well as the time courses of radionuclide ratios show characteristic differences between air and deposition. The data will be useful in predicting the post-accident behaviour of radionuclides a long time after a large-scale contamination event.

  1. Biokinetics of a transuranic ({sup 238}PU) and a rare earth element ({sup 152}Eu) in the lobster (Homarus gammarus): transfer mechanisms (accumulation and detoxification) in organs and at the cellular level; Biocinetiques d'un element transuranien, le {sup 238}PU, et d'une terre rare, le {sup 152}EU, chez le homard homarus gammarus (organes et niveau cellulaire) modalites des transferts (accumulation et detoxication)

    Energy Technology Data Exchange (ETDEWEB)

    Tocquet, N

    1995-07-01

    The work presented here is an experimental investigation of the biokinetics of transfer of a transuranic and a rare earth element ({sup 238}Pu and {sup 152}Eu) in the lobster Homarus gammarus. The study of {sup 238}Pu biokinetics forms part of a wider framework of research concerning the transfer of transuranic elements in marine species, while the study of {sup 152}Eu is carried out with a view to supporting the analogy between the behaviour of transuranics and rare earths in living organisms. Exactly the same experimental protocol, based on techniques from various disciplines (biology, biochemistry and metrology), was used to Investigate the biokinetics of transfer of these two radionuclides. The Individual lobsters were radiolabelled by means of one-shot or chronic ingestion of spiked meals. As the first approach, the kinetics and transfer mechanisms were studied In whole animal samples and in different organs distinct series of pathways through the different organs were identified in the case of both radionuclides, being mainly linked to digestive processes induced by the meal as well as the transport function of hemo-lymph in this way, the Important role of the digestive gland was picked out, with two of four cellular types displaying a successive involvement In the fixation and then the retention of the studied radionuclides. As a corroborative approach, the digestive gland was subjected to a more detailed investigation with the aim of describing the mechanisms of Incorporation and elucidating transfer processes at the cellular and molecular levels. {sup 238}Pu is preferentially partitioned into the cytosol, where it is associated with various constituents such as ferritin (iron-storing protein). {sup 152}Eu is more diffusely distributed in the hepato-pancreatic cells, while the lysosomes appear to play a more important role during transfer. The results obtained in this study, both on the macroscopic scale (i.e. the whole animal and different organs) as well

  2. Observation of New Neutron-rich Isotopes among Fission Fragments from In-flight Fission of 345 MeV/nucleon 238U: Search for New Isotopes Conducted Concurrently with Decay Measurement Campaigns

    Science.gov (United States)

    Shimizu, Yohei; Kubo, Toshiyuki; Fukuda, Naoki; Inabe, Naohito; Kameda, Daisuke; Sato, Hiromi; Suzuki, Hiroshi; Takeda, Hiroyuki; Yoshida, Koichi; Lorusso, Giuseppe; Watanabe, Hiroshi; Simpson, Gary S.; Jungclaus, Andrea; Baba, Hidetada; Browne, Frank; Doornenbal, Pieter; Gey, Guillaunme; Isobe, Tadaaki; Li, Zhihuan; Nishimura, Shunji; Söderström, Pär-Anders; Sumikama, Toshiyuki; Taprogge, Jan; Vajta, Zsolt; Wu, Jin; Xu, Zhengyu; Odahara, Atsuko; Yagi, Ayumi; Nishibata, Hiroki; Lozeva, Radomira; Moon, Changbum; Jung, HyoSoon

    2018-01-01

    The search for new isotopes using the in-flight fission of a 238U beam has been conducted concurrently with decay measurements, during the so-called EURICA campaigns, at the RIKEN Nishina Center RI Beam Factory. Fission fragments were analyzed and identified in flight using the BigRIPS separator. We have identified the following 36 new neutron-rich isotopes: 104Rb, 113Zr, 116Nb, 118,119Mo, 121,122Tc, 125Ru, 127,128Rh, 129,130,131Pd, 132Ag, 134Cd, 136,137In, 139,140Sn, 141,142Sb, 144,145Te, 146,147I, 149,150Xe, 149,150,151Cs, 153,154Ba, and 154,155,156,157La.

  3. Fission-fragment total kinetic energy and mass yields for neutron-induced fission of 235U and 238U with En =200 keV - 30 MeV

    Science.gov (United States)

    Duke, D. L.; Tovesson, F.; Brys, T.; Geppert-Kleinrath, V.; Hambsch, F.-J.; Laptev, A.; Meharchand, R.; Manning, B.; Mayorov, D.; Meierbachtol, K.; Mosby, S.; Perdue, B.; Richman, D.; Shields, D.; Vidali, M.

    2017-09-01

    The average Total Kinetic Energy (TKE) release and fission-fragment yields in neutron-induced fission of 235U and 238U was measured using a Frisch-gridded ionization chamber. These observables are important nuclear data quantites that are relevant to applications and for informing the next generation of fission models. The measurements were performed a the Los Alamos Neutron Science Center and cover En = 200 keV - 30 MeV. The double-energy (2E) method was used to determine the fission-fragment yields and two methods of correcting for prompt-neutron emission were explored. The results of this study are correlated mass and TKE data.

  4. Fission-fragment total kinetic energy and mass yields for neutron-induced fission of 235U and 238U with En =200 keV – 30 MeV

    Directory of Open Access Journals (Sweden)

    Duke D.L.

    2017-01-01

    Full Text Available The average Total Kinetic Energy (TKE release and fission-fragment yields in neutron-induced fission of 235U and 238U was measured using a Frisch-gridded ionization chamber. These observables are important nuclear data quantites that are relevant to applications and for informing the next generation of fission models. The measurements were performed a the Los Alamos Neutron Science Center and cover En = 200 keV – 30 MeV. The double-energy (2E method was used to determine the fission-fragment yields and two methods of correcting for prompt-neutron emission were explored. The results of this study are correlated mass and TKE data.

  5. Measurement of the average energy and multiplicity of prompt-fission neutrons from {sup 238}U(n,f) and {sup 237}Np(n,f) from 1 to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Taieb, J.; Granier, T.; Ethvignot, T. [CEA Bruyeres-le-Chatel (DPTA/SPN), 91 (France). Dept. de Physique Theorique et Appliquee; Devlin, M.; Haight, R.C.; Nelson, R.O.; O' Donnell, J.M. [Los Alamos National Laboratory, LANSCE, MS H855, Los Alamos, New Mexico (United States); Rochman, D. [Brookhaven National Laboratory (NNDC), Upton, NY (United States)

    2008-07-01

    Taking advantage of the neutron source of the LANCSE, it has been possible to obtain a measure of the velocity distribution and the number of prompt-neutrons emitted in the neutron-induced fission of {sup 238}U and {sup 237}Np over a broad incident neutron energy range from 1 to 200 MeV. The mean kinetic energy was extracted and is shown as a function of the incident-neutron energy. We confirm here the observation, for both reactions, of a dip around the second-chance fission which is explained by the lower kinetic energy of the pre-fission neutrons. Such a observation is reproduced by Los Alamos model and by the Maslov model. As far as the neutron multiplicity is concerned, a similar dip is observed. (authors)

  6. Spin-alignment and g-factor measurement of the I{sup {pi}}=12{sup +} isomer in {sup 192}Pb produced in the relativistic-energy fragmentation of a {sup 238}U beam

    Energy Technology Data Exchange (ETDEWEB)

    Kmiecik, M.; Maj, A.; Ciemala, M.; Grebosz, J.; Lach, M.; Maier, K.H.; Mazurek, K.; Meczynski, W.; Myalski, S.; Styczen, J.; Zieblinski, M. [H. Niewodniczanski Inst. of Nuclear Physics PAN, Krakow (Poland); Gerl, J.; Becker, F.; Caceres, L.; Doornenbal, P.; Gorska, M.; Grawe, H.; Kojuharov, I.; Prokopowicz, W.; Saito, N.; Saito, T.R.; Wollersheim, H.J. [GSI, Darmstadt (Germany); Neyens, G.; Mallion, S.; Vermeulen, N. [Inst. voor Kern- en Stralingsfysica, K.U. Leuven (Belgium); Atanasova, L.; Detistov, P. [Univ. of Sofia ' St. Kl. Ohridski' (Bulgaria). Faculty of Physics; Balabanski, D.L. [Univ. degli Studi di Camerino (Italy); INFN sez. Perugia, Dipt. di Fisica, Camerino (Italy); Bulgarian Academy of Sciences, Inst. for Nuclear Research and Nuclear Energy, Sofia (Bulgaria); Bednarczyk, P. [H. Niewodniczanski Inst. of Nuclear Physics PAN, Krakow (Poland); GSI, Darmstadt (Germany); Benzoni, G.; Blasi, N.; Brambilla, S.; Million, B.; Wieland, O. [INFN Sez. di Milano (Italy); Bracco, A.; Camera, F.; Crespi, F.C.L.; Leoni, S.; Montanari, D. [INFN Sez. di Milano (Italy); Univ. degli Studi di Milano (Italy); Chamoli, S.K.; Hass, M.; Lakshmi, S. [Weizman Inst. of Science, Rehovot (Israel); Chmel, S. [Fraunhofer INT, Euskirchen (Germany); Daugas, J.M. [CEA, DAM, DIF, Arpajon Cedex (France); Georgiev, G. [Univ. Paris-Sud 11, CNRS/IN2P3, CSNSM, Orsay-Campus (France); Gladnishki, K. [Univ. of Sofia ' St. Kl. Ohridski' (Bulgaria). Faculty of Physics; Univ. degli Studi di Camerino (Italy); INFN sez. Perugia, Dipt. di Fisica, Camerino (Italy); Hoischen, R.; Rudolph, D. [Lund Univ., Dept. of Physics, Lund (Sweden); Ilie, G. [Univ. zu Koeln, Inst. fuer Kernphysik, Koeln (Germany); National Inst. for Physics and Nuclear Engineering, Bucharest (Romania); Ionescu-Bujor, M. [National Inst. for Physics and Nuclear Engineering, Bucharest (Romania); Jolie, J. [Univ. zu Koeln, Institut fuer Kernphysik, Koeln (Germany)] [and others

    2010-08-15

    The feasibility of measuring g -factors using the TDPAD method applied to high-energy, heavy fragmentation products is explored. The 2623keV I{sup {pi}}=12{sup +} isomer in {sup 192}Pb with {tau}=1.57{mu}s has been produced using the fragmentation of a 1A GeV {sup 238}U beam. The results presented demonstrate for the first time that such heavy nuclei produced in a fragmentation reaction with a relativistic beam are sufficiently well spin-aligned. Moreover, the rather large value of the alignment, 28(10)% of the maximum possible, is preserved during the separation process allowing the determination of magnetic moments. The measured values of the lifetime, {tau}=1.54(9) {mu}s, and the g-factor, g=-0.175(20), agree with the results of previous investigations using fusion-evaporation reactions. (orig.)

  7. Carbon export fluxes and export efficiency in the central Arctic during the record sea-ice minimum in 2012: a joint 234Th/238U and 210Po/210Pb study

    Science.gov (United States)

    Roca-Martí, Montserrat; Puigcorbé, Viena; Rutgers van der Loeff, Michiel M.; Katlein, Christian; Fernández-Méndez, Mar; Peeken, Ilka; Masqué, Pere

    2016-07-01

    The Arctic sea-ice extent reached a record minimum in September 2012. Sea-ice decline increases the absorption of solar energy in the Arctic Ocean, affecting primary production and the plankton community. How this will modulate the sinking of particulate organic carbon (POC) from the ocean surface remains a key question. We use the 234Th/238U and 210Po/210Pb radionuclide pairs to estimate the magnitude of the POC export fluxes in the upper ocean of the central Arctic in summer 2012, covering time scales from weeks to months. The 234Th/238U proxy reveals that POC fluxes at the base of the euphotic zone were very low (2 ± 2 mmol C m-2 d-1) in late summer. Relationships obtained between the 234Th export fluxes and the phytoplankton community suggest that prasinophytes contributed significantly to the downward fluxes, likely via incorporation into sea-ice algal aggregates and zooplankton-derived material. The magnitude of the depletion of 210Po in the upper water column over the entire study area indicates that particle export fluxes were higher before July/August than later in the season. 210Po fluxes and 210Po-derived POC fluxes correlated positively with sea-ice concentration, showing that particle sinking was greater under heavy sea-ice conditions than under partially ice-covered regions. Although the POC fluxes were low, a large fraction of primary production (>30%) was exported at the base of the euphotic zone in most of the study area during summer 2012, indicating a high export efficiency of the biological pump in the central Arctic.

  8. Tracing of natural radionuclides mobility in deep sedimentary environment using radioactive ({sup 234}U/{sup 238}U) disequilibria: application to the Mesozoic formations of the Eastern part of the Paris Basin; Tracage de la mobilite des radionucleides naturels en milieu sedimentaire profond a l'aide des desequilibres radioactifs ({sup 234}U/{sup 238}U): application aux formations mesozoiques de l'est du Bassin de Paris

    Energy Technology Data Exchange (ETDEWEB)

    Deschamps, P

    2003-11-01

    This thesis forms part of the geological investigations undertaken by the French agency for nuclear waste management, ANDRA, around the Meuse/Haute-Marne Underground Research Laboratory (URL) located in the Eastern part of the Paris Basin in order to evaluate the feasibility of high-level radioactive waste repository in deep argilite formations. The aim of the study is to examine the radionuclide migration in the deep Callovo-Oxfordian target argilite layer and its surrounding low- permeability Bathonian and Oxfordian limestone formations in order to assess the long term confining capacities of the sedimentary series. This study is based on measurement of radioactive disequilibria within U-series by Multiple- Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS). The high precision and accuracy achieved allowed to demonstrate the {sup 234}U/{sup 238}U radioactive equilibrium in the Callovo-Oxfordian argilites. This result shows the uranium immobility in the target formation and provides a strong evidence for the current chemical stability and closure of the system for uranium and most probably for the other actinides. This is a fundamental result with respect to the problematic of disposal of high level radioactive waste in deep geological formation since it provides a in situ indication of the confining capacities of the clayey target formation in the current settings. Conversely, ({sup 234}U/{sup 238}U) disequilibria are systematically observed within zones, located in the surrounding carbonate formations, that are characterized by pressure dissolution structures (stylolites or dissolution seams). These disequilibria provide evidence for a discrete uranium relocation during the last two million years in the vicinity of stylolitic structures. This is a surprising result since it is generally supposed that these deep, low permeability, compact formations behave as closed system at the time scale of the U-series. (author)

  9. Potential Human Health Risk by Metal(loid)s, 234,238U and 210Po due to Consumption of Fish from the “Luis L. Leon” Reservoir (Northern México)

    Science.gov (United States)

    Luna-Porres, Mayra Y.; Rodríguez-Villa, Marco A.; Herrera-Peraza, Eduardo F.; Renteria-Villalobos, Marusia; Montero-Cabrera, María E.

    2014-01-01

    Concentrations of As, Cu, Fe, Hg, Pb and Zn and activity concentrations from 234,238U and 210Po in water, fillet, liver and gills were determined in three stocked fish species from the Luis L. Leon reservoir, located in Northern Mexico. The considered species were Lepomis cyanellus, Cyprinus carpio and Ictalurus furcatus. 238U and 234U activity concentration (AC) in fillet samples showed values of 0.007–0.014 and 0.01–0.02 Bq∙kg−1 wet weight (ww), respectively. Liver samples for L. cyanellus, C. carpio and I. furcatus present 210Po AC of 1.16–3.26, 0.70–1.13 and 0.93–1.37 Bq∙kg−1 ww. Arsenic, mercury and lead concentration intervals in fillet samples were 0.13–0.39, 0.005–0.126 and 0.009–0.08 mg∙kg−1 ww, respectively, while in gill samples they were 0.11–0.43, 0.002–0.039 and 0.02–0.26 mg∙kg−1 ww. The elemental Bioaccumulation Factor (BAF) for fish tissues with respect to their concentrations in water was determined. L. cyanellus showed the highest BAF values for As and total U, being BAFAs = 37 and 40 L∙kg−1 in fillet and gills, respectively, and BAFU total = 1.5 L∙kg−1 in fillet. I. furcatus showed the highest BAF values for Hg and Pb, being BAFHg = 40 and 13 L∙kg−1 in fillet and gills, and BAFPb = 6.5 and 22 L∙kg−1 in fillet and gills, respectively. Some metal(loid) concentrations are slightly higher than European regulations for fish fillets. The difference in concentrations of metal(loid)s in fillet among the studied species is probably due to their differences in diet and habitat. PMID:24968208

  10. Potential Human Health Risk by Metal(loids, 234,238U and 210Po due to Consumption of Fish from the “Luis L. Leon” Reservoir (Northern México

    Directory of Open Access Journals (Sweden)

    Mayra Y. Luna-Porres

    2014-06-01

    Full Text Available Concentrations of As, Cu, Fe, Hg, Pb and Zn and activity concentrations from 234,238U and 210Po in water, fillet, liver and gills were determined in three stocked fish species from the Luis L. Leon reservoir, located in Northern Mexico. The considered species were Lepomis cyanellus, Cyprinus carpio and Ictalurus furcatus. 238U and 234U activity concentration (AC in fillet samples showed values of 0.007–0.014 and 0.01–0.02 Bq∙kg−1 wet weight (ww, respectively. Liver samples for L. cyanellus, C. carpio and I. furcatus present 210Po AC of 1.16–3.26, 0.70–1.13 and 0.93–1.37 Bq∙kg−1 ww. Arsenic, mercury and lead concentration intervals in fillet samples were 0.13–0.39, 0.005–0.126 and 0.009–0.08 mg∙kg−1 ww, respectively, while in gill samples they were 0.11–0.43, 0.002–0.039 and 0.02–0.26 mg∙kg−1 ww. The elemental Bioaccumulation Factor (BAF for fish tissues with respect to their concentrations in water was determined. L. cyanellus showed the highest BAF values for As and total U, being BAFAs = 37 and 40 L∙kg−1 in fillet and gills, respectively, and BAFU total = 1.5 L∙kg−1 in fillet. I. furcatus showed the highest BAF values for Hg and Pb, being BAFHg = 40 and 13 L∙kg−1 in fillet and gills, and BAFPb = 6.5 and 22 L∙kg−1 in fillet and gills, respectively. Some metal(loid concentrations are slightly higher than European regulations for fish fillets. The difference in concentrations of metal(loids in fillet among the studied species is probably due to their differences in diet and habitat.

  11. Sequential determination of natural ({sup 232}Th, {sup 238}U) and anthropogenic ({sup 137}Cs, {sup 90}Sr, {sup 241}Am, {sup 239+240}Pu) radionuclides in environmental matrix

    Energy Technology Data Exchange (ETDEWEB)

    Michel, H.; Levent, D.; Barci, V.; Barci-Funel, G.; Hurel, C. [Laboratoire de Radiochimie, Sciences Analytiques et Environnement (LRSAE), Universite de Nice Sophia-Antipolis 06108 Nice Cedex (France)

    2008-07-01

    A new sequential method for the determination of both natural (U, Th) and anthropogenic (Sr, Cs, Pu, Am) radionuclides has been developed for application to soil and sediment samples. The procedure was optimised using a reference sediment (IAEA-368) and reference soils (IAEA-375 and IAEA-326). Reference materials were first digested using acids (leaching), 'total' acids on hot plate, and acids in microwave in order to compare the different digestion technique. Then, the separation and purification were made by anion exchange resin and selective extraction chromatography: Transuranic (TRU) and Strontium (SR) resins. Natural and anthropogenic alpha radionuclides were separated by Uranium and Tetravalent Actinide (UTEVA) resin, considering different acid elution medium. Finally, alpha and gamma semiconductor spectrometer and liquid scintillation spectrometer were used to measure radionuclide activities. The results obtained for strontium-90, cesium-137, thorium-232, uranium- 238, plutonium-239+240 and americium-241 isotopes by the proposed method for the reference materials provided excellent agreement with the recommended values and good chemical recoveries. (authors)

  12. Estimation of multi-group cross section covariances for {sup 235,238}U, {sup 239}Pu, {sup 241}Am, {sup 56}Fe, {sup 23}Na and {sup 27}Al

    Energy Technology Data Exchange (ETDEWEB)

    De Saint Jean, C.; Archier, P.; Noguere, G.; Litaize, O.; Vaglio-Gaudard, C.; Bernard, D.; Leray, O. [CEA, DEN, DER, Cadarache, F-13108 Saint-Paul-lez-Durance (France)

    2012-07-01

    This paper presents the methodology used to estimate multi-group covariances for some major isotopes used in reactor physics. The starting point of this evaluation is the modelling of the neutron induced reactions based on nuclear reaction models with parameters. These latest are the vectors of uncertainties as they are absorbing uncertainties and correlation arising from the confrontation of nuclear reaction model to microscopic experiment. These uncertainties are then propagated towards multi-group cross sections. As major breakthroughs were then asked by nuclear reactor physicists to assess proper uncertainties to be used in applications, a solution is proposed by the use of integral experiment information at two different stages in the covariance estimation. In this paper, we will explain briefly the treatment of all type of uncertainties, including experimental ones (statistical and systematic) as well as those coming from validation of nuclear data on dedicated integral experiment (nuclear data oriented). We will illustrate the use of this methodology with various isotopes such as {sup 235,238}U, {sup 239}Pu, {sup 241}Am, {sup 56}Fe, {sup 23}Na and {sup 27}Al. (authors)

  13. Estimation of covariances of {sup 16}O, {sup 23}Na, Fe, {sup 235}U, {sup 238}U and {sup 239}Pu neutron nuclear data in JENDL-3.2

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Keiichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nakajima, Yutaka; Kawano, Toshihiko; Oh, Soo-Youl; Matsunobu, Hiroyuki; Murata, Toru

    1997-10-01

    Covariances of nuclear data have been estimated for 6 nuclides contained in JENDL-3.2. The nuclides considered are {sup 16}O, {sup 23}Na, Fe, {sup 235}U, {sup 238}U, and {sup 239}Pu, which are regarded as important for the nuclear design study of fast reactors. The physical quantities for which covariances are deduced are cross sections, resolved and unresolved resonance parameters, and the first order Legendre-polynomial coefficient for the angular distribution of elastically scattered neutrons. As for {sup 235}U, covariances were obtained also for the average number of neutrons emitted in fission. The covariances were estimated by using the same methodology that had been used in the JENDL-3.2 evaluation in order to keep a consistency between mean values and their covariances. The least-squares fitting code GMA was used in estimating covariances for reactions of which JENDL-3.2 cross sections had been evaluated by taking account of measurements. In nuclear model calculations, the covariances were calculated by the KALMAN system. The covariance data obtained were compiled in the ENDF-6 format, and will be put into the JENDL-3.2 Covariance File which is one of JENDL special purpose files. (author). 193 refs.

  14. Neutron Resonance Parameters of 238U and the Calculated Cross Sections from the Reich-Moore Analysis of Experimental Data in the Neutron Energy Range from 0 keV to 20 keV

    Energy Technology Data Exchange (ETDEWEB)

    Derrien, H

    2005-12-05

    The neutron resonance parameters of {sup 238}U were obtained from a SAMMY analysis of high-resolution neutron transmission measurements and high-resolution capture cross section measurements performed at the Oak Ridge Electron Linear Accelerator (ORELA) in the years 1970-1990, and from more recent transmission and capture cross section measurements performed at the Geel Linear Accelerator (GELINA). Compared with previous evaluations, the energy range for this resonance analysis was extended from 10 to 20 keV, taking advantage of the high resolution of the most recent ORELA transmission measurements. The experimental database and the method of analysis are described in this report. The neutron transmissions and the capture cross sections calculated with the resonance parameters are compared with the experimental data. A description is given of the statistical properties of the resonance parameters and of the recommended values of the average parameters. The new evaluation results in a slight decrease of the effective capture resonance integral and improves the prediction of integral thermal benchmarks by 70 pcm to 200 pcm.

  15. Neutron Protection Factor Determination and Validation for a Vehicle Surrogate Using a Californium Fission Source

    Science.gov (United States)

    2017-06-01

    a 4 mm x 4 mm (0.157" x 0.157") LiI(Eu) crystal with 96% enrichment of lithium -6. The crystal is connected to a photomultiplier tube (PMT) which...32 Figure 17. Lithium -6 Iodide, Europium Doped Scintillation Detector. Source: [27...Alamos National Laboratory LiI(Eu) Lithium Iodide Europium Doped LLD Low Level Discriminator LLNL Lawrence Livermore National Laboratory MASH Monte

  16. 49 CFR 238.103 - Fire safety.

    Science.gov (United States)

    2010-10-01

    ... considerations and features in the design of this equipment reduce the risk of personal injury caused by fire to... risk of initiating fire and which requires overheat protection. An overheat detector shall be installed... any part of the equipment structure that is not normally occupied during operation of the train...

  17. Publications | Page 238 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The research aimed to enhance the evidence base on links between migration and development at the national and regional scale within the South African Development Community (SADC) and internationally, and to examine implications for both national and regional immigration and development policy.

  18. 40 CFR 238.20 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING DEGRADABLE PLASTIC RING... means the percent increase in length of the plastic material caused by a tensile load. Percent... entities that produce ring carriers ready for use as beverage carriers. Ring carrier means any plastic ring...

  19. 49 CFR 238.5 - Definitions.

    Science.gov (United States)

    2010-10-01

    ... the locomotive engineer. Failure by the locomotive engineer to institute a change of state in a...-climbing resistance and to reduce the risk of train buckling during a collision. Crash refuge means a... department, or other organization involved with public safety charged with providing or coordinating...

  20. Plutonium 238/239 Decorporation Model

    Science.gov (United States)

    2014-10-01

    for acute effects and Pu is immobilized in bone RBM exposure to radionuclides may cause acute affects, such as the hematopoietic radiation syndrome ...the external dose contribution would be targeted toward acute radiation syndrome rather than decorporation. As stated previously, this particular...from the portion of the Pu absorbed, particularly from Pu immobilized in the bone compartment. Therefore, the biokinetic model is required for

  1. TMFunction data: 238 [TMFunction[Archive

    Lifescience Database Archive (English)

    Full Text Available HC. J Biol Chem. 2000 Jul 14;275(28):21017-24 mutagenesis ... affinity chromatography 1AJJ ... LDLR_HUMAN (P01130) Helix ... ligand binding site; surface exposed; acidic residue; conserved

  2. Publications | Page 238 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Annex 35] (open access). This project addresses knowledge, resource, capacity and networking gaps on the theme: ''Strengthening urban governments in planning adaptation.'' The main objective of this project is to develop an adaptation ...

  3. 9 CFR 2.38 - Miscellaneous.

    Science.gov (United States)

    2010-01-01

    ...) The use of a room, table or other facilities necessary for the proper examination of the records and... prevent the spread of disease, including the use of sterile clothing, footwear, and masks where required... otherwise handle animals. (ii) Deprivation of food or water shall not be used to train, work, or otherwise...

  4. Publications | Page 238 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    We share the results of our funded research, and offer free training materials to guide researchers and institutions. Want more? ... Taxation has proved to be the single most effective tool in reducing tobacco consumption and smoking prevalence. ... Focus Cities: Improving water, sanitation, and solid waste management.

  5. Magma mixing and the generation of isotopically juvenile silicic magma at Yellowstone caldera inferred from coupling 238U–230Th ages with trace elements and Hf and O isotopes in zircon and Pb isotopes in sanidine

    Science.gov (United States)

    Stelten, Mark E.; Cooper, Kari M.; Vazquez, Jorge A.; Reid, Mary R.; Barfod, Gry H.; Wimpenny, Josh; Yin, Qing-Zhu

    2013-01-01

    The nature of compositional heterogeneity within large silicic magma bodies has important implications for how silicic reservoirs are assembled and evolve through time. We examine compositional heterogeneity in the youngest (~170 to 70 ka) post-caldera volcanism at Yellowstone caldera, the Central Plateau Member (CPM) rhyolites, as a case study. We compare 238U–230Th age, trace-element, and Hf isotopic data from zircons, and major-element, Ba, and Pb isotopic data from sanidines hosted in two CPM rhyolites (Hayden Valley and Solfatara Plateau flows) and one extracaldera rhyolite (Gibbon River flow), all of which erupted near the caldera margin ca. 100 ka. The Hayden Valley flow hosts two zircon populations and one sanidine population that are consistent with residence in the CPM reservoir. The Gibbon River flow hosts one zircon population that is compositionally distinct from Hayden Valley flow zircons. The Solfatara Plateau flow contains multiple sanidine populations and all three zircon populations found in the Hayden Valley and Gibbon River flows, demonstrating that the Solfatara Plateau flow formed by mixing extracaldera magma with the margin of the CPM reservoir. This process highlights the dynamic nature of magmatic interactions at the margins of large silicic reservoirs. More generally, Hf isotopic data from the CPM zircons provide the first direct evidence for isotopically juvenile magmas contributing mass to the youngest post-caldera magmatic system and demonstrate that the sources contributing magma to the CPM reservoir were heterogeneous in 176Hf/177Hf at ca. 100 ka. Thus, the limited compositional variability of CPM glasses reflects homogenization occurring within the CPM reservoir, not a homogeneous source.

  6. Dynamics of {sup 40,48}Ca+{sup 238}U→{sup 278,286}112{sup ⁎} reactions across the Coulomb barrier using dynamical cluster decay model

    Energy Technology Data Exchange (ETDEWEB)

    Sandhu, Kirandeep; Kaur, Gurvinder; Sharma, Manoj K., E-mail: msharma@thapar.edu

    2014-01-15

    The role of deformations and related orientations (optimum or compact) is investigated in reference to dynamics of {sup 40,48}Ca+{sup 238}U→{sup 278,286}112{sup ⁎} reactions using dynamical cluster decay model (DCM). The use of quadrupole and hexadecapole deformations in the decay of compound system suggest that the degree of compactness changes with addition of higher order deformations. The decay cross-sections are calculated in reference to the available data, including β{sub 2}-static deformations within ‘optimum’ orientation approach. The comparative analysis of spherical, β{sub 2}-static and dynamic alongwith β{sub 4}-static deformations is investigated at comparable center of mass energy of 230 MeV for both nuclei. To address the specific role of optimized orientations in the decay of {sup 278}112{sup ⁎} and {sup 286}112{sup ⁎} nuclei, the calculations are done using equatorial compact and polar elongated orientations. Using hot equatorial collisions, symmetric fission is observed as the dominant decay mode across the barrier, which otherwise becomes asymmetric for cold elongated approach. The calculated cross-sections match nicely with experimental data using hot configuration but the same are overestimated for the use of cold (polar) orientation approach at deep sub-barrier region. This overestimation in the deep sub-barrier region may be associated with the quasi-fission decay channel. The contribution of QF in both {sup 278}112{sup ⁎} and {sup 286}112{sup ⁎} nuclei are predicted through the overestimated cross-sections being more for neutron-deficient {sup 278}112{sup ⁎} nucleus, in agreement with experimental results. Larger barrier modification ΔV{sub B} is observed at sub-barrier energies for both isotopes of Z=112 nucleus. Also the contribution of ΔV{sub B} at lower incident energies is relatively higher for cold elongated polar configuration as compared to hot compact equatorial configuration, causing overestimation of cross

  7. Circulatory kinetics of intravenously injected {sup 238}Pu(IV) citrate and {sup 14}C-CaNa{sub 3}-DTPA in mice: Comparison with rat, dog, and Reference Man

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, P.W.; Kullgren, B.; Schmidt, C.T. [Lawrence Berkeley National Lab., CA (United States)

    1997-02-01

    New ligands for in vivo chelation of Pu(IV) are being synthesized and evaluated in mice for efficacy and toxicity. Biokinetic studies of the new ligands, CaNa{sub 3}-DTPA, and Pu(IV) are major components of those investigations. Young adult female mice were injected intravenously (iv) with {sup 3}H-inulin, {sup 14}C-CaNa{sub 3}-DTPA, or {sup 238}Pu(IV) citrate to provide base- line data for plasma clearance, tissue uptake, and excretion rates and to determine the dilution volume (VOD) and renal clearance rate (RC) of filterable substances. Published plasma clearance data in Reference Man, dog, and rat were collected. Based on combined data for {sup 3}H-inulin and {sup 14}C-CaNa{sub 3}-DTPA, VOD = 17% of body weight and RC = 18 mL kg{sup -1} min{sup -1} for mice. Retention of {sup 14}C-CaNa{sub 3}-DTPA in the four species is proportional to body weight and inversely proportional to RC: Integrals of the retention of {sup 14}C-CaNa{sub 3}-DTPA from R(t) = 1.0 to R(t) = 0.05 are 108, 43, 28, and 10 DF min, respectively, for Reference Man, dog, rat, and mouse. Clearances of iv-injected Pu(IV) citrate from plasma are in the same order: The plasma curve integrals from injection to 1440 min are 840, 640, 280, and 67 DF min, respectively, for Reference Man, dog, rat, and mouse. In mice, a large fraction of newly injected Pu(IV) is rapidly transferred to the interstitial water of bulk soft tissue (excluding liver and kidneys), from which it is cleared at the same rate as from the plasma. Rapid plasma clearance, escape into interstitial water (22%ID at 20 min), significant early urinary excretion (8%ID in 12 h), and prompt deposition in liver and skeleton (complete in 12 h) are evidence of inefficient binding to plasma protein of newly injected Pu(IV) in mice. Slow plasma clearance, little early urinary excretion, and delayed deposition in liver and skeleton reflect more efficient binding of newly injected Pu(IV) in Reference Man and dog. 39 refs., 6 figs., 3 tabs.

  8. Quantification of {sup 232}Th, {sup 234}U, {sup 235}U and {sup 238}U in river mollusks by magnetic sector mass spectrometry with inductively coupled plasma source (Icp-SFMS); Cuantificacion de {sup 232}Th, {sup 234}U, {sup 235}U y {sup 238}U en moluscos de rios por espectrometria de masas de sector magnetico con fuente de plasma acoplado inductivamente (ICP-SFMS)

    Energy Technology Data Exchange (ETDEWEB)

    Arevalo R, D. L.; Hernandez M, H.; Romero G, E. T.; Lara A, N. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Alfaro de la T, M. C., E-mail: arevalo0591@hotmail.com [Universidad Autonoma de San Luis Potosi, Dr. Salvador Nava s/n, Zona Universitaria, 78290 San Luis Potosi, SLP (Mexico)

    2016-09-15

    The present work deals with the methodology established for the quantification of {sup 232}Th, {sup 234}U, {sup 238}U and {sup 235}U in the shell of gastropod mollusks collected in the rivers Valles, Coy and Axtla of San Luis Potosi, Mexico, which belong to the Panuco River basin; these rivers have as main source of pollution the discharge of municipal sewage, waste from small industries, agricultural and cattle residues and from natural sources. Conventional methods for measuring radio-nuclides are confronted with certain conditions related to the requirement in measurement, basically in the characterization that is related to the concepts of precision and accuracy. The analysis of the gastropod mollusk shell was performed by the Icp-SFMS technique; the main advantages of this technique lie in the isotope quantification capacity, the high precision and the low limits of detection, in this study are very important because these elements are in concentrations between ppb and ppt. This technique allowed the analysis of the samples having a complex matrix by the presence CaCO{sub 3} minimizing the interferences thanks to the ionization efficiency of the Ar plasma. For the species Pachychilus monachus were found concentrations of {sup 232}Th of 0.16-5.37 μg/g and of total U of 0.101-4.081 μg/g being this species where the highest values of total U were found. For Thiara (melanoids) tuberculata the lowest values were found among the different species ({sup 232}Th 0.61-3.61 μg/g and total U 0.006-0.042 μg/g), for Pachychilus suturalis, values of {sup 232}Th of 0.58-6.4 μg/g and for Pachychilus sp. were found between 0.26-7.62 μg/g and for total U values between 0.28-3.33 μg/g. The method offers several advantages: speed, good precision, low values of quantification limits and high sensitivity in the measurement of radio-nuclides and heavy metals. (Author)

  9. 49 CFR 238.317 - Class II brake test.

    Science.gov (United States)

    2010-10-01

    ....315(a)(1); (3) When previously tested units (i.e., cars that received a Class I brake test within the... hours) are added to the train; (4) When cars or equipment are removed from the train; and (5) When an... locomotives that utilize an electric signal to communicate a service brake application and only a pneumatic...

  10. 1935 15' Quad #238 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  11. 7 CFR 58.238 - Condensed storage tanks.

    Science.gov (United States)

    2010-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) GRADING AND INSPECTION...

  12. 49 CFR 238.229 - Safety appliances-general.

    Science.gov (United States)

    2010-10-01

    ... for Safety reserves the right to disapprove any exclusion recommended by the railroad in paragraphs (c... defect in a weld due to crash damage (i.e., impact of the safety appliance by an outside force during... nature of the repair to any welded safety appliance bracket or support identified in paragraph (e) of...

  13. Dicty_cDB: VFL238 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available dehydrogenase; EC=1.1.1.3... 203 8e-51 (Q1LKG0) RecName: Full=Malate dehydrogenase; EC=1.1.1.3... 199 1e-49...(Q0K8F5) RecName: Full=Malate dehydrogenase; EC=1.1.1.3... 197 3e-49 CU633749_2079( CU633749 |pid:none)...(Q46YU4) RecName: Full=Malate dehydrogenase; EC=1.1.1.3... 197 6e-49 CP000934_1926( CP000934 |pid:none)...dehydrogenase; EC=1.1.1.3... 194 4e-48 NRL( 1BDMB ) malate dehydrogenase (EC 1.1.1.37) mutant (T189I)

  14. 49 CFR 238.230 - Safety appliances-new equipment.

    Science.gov (United States)

    2010-10-01

    ... drawings, sketches, or other visual aids that provide detailed information relating to the design, location...; (v) The weld is designed for infinite fatigue life in the application that it will be placed; (vi... railroad provides a detailed basis as to why the design of the vehicle or placement of the safety appliance...

  15. 7 CFR 205.238 - Livestock health care practice standard.

    Science.gov (United States)

    2010-01-01

    ...) ORGANIC FOODS PRODUCTION ACT PROVISIONS NATIONAL ORGANIC PROGRAM Organic Production and Handling... as organic. (c) The producer of an organic livestock operation must not: (1) Sell, label, or represent as organic any animal or edible product derived from any animal treated with antibiotics, any...

  16. Phenotype-gene: 238 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available d in organ named vascular leaf during process named senescence in environment of continuous dark (no light) ... during process named senescence in environment of continuous dark (no light) regimen http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u738i AT5G05700

  17. Dicty_cDB: SSB238 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 031_1( K02031 |pid:none) Variola major virus thymidine kinase g... 139 3e-32 AF163843_1( AF163843 |pid:none) Ectromelia...139 4e-32 AF012825_78( AF012825 |pid:none) Ectromelia virus strain Moscow, c... 139 4e-32 protein update 200

  18. 49 CFR 238.311 - Single car test.

    Science.gov (United States)

    2010-10-01

    ... railroad shall perform a single car test of the brake system of a car or vehicle described in paragraph (a... defective brake system on the car. (e) Except as provided in paragraph (f) of this section, a railroad shall perform a single car test of the brake system of a car or vehicle described in paragraph (a) of this...

  19. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Science.gov (United States)

    2010-10-01

    ... with other than an AB, ABD, ABDX, 26-C, or equivalent brake system. (e) Cab cars. The brake equipment... schedule: (1) Every 1,476 days for that portion of the cab car brake system using brake valves that are identical to the passenger coach 26-C brake system; (2) Every 1,104 days for that portion of the cab car...

  20. 49 CFR 238.313 - Class I brake test.

    Science.gov (United States)

    2010-10-01

    ... side of each car's brake system responds properly to application and release signals; (2) The brake... applied on each car in the train until a release of the brakes has been initiated on each car in response... operating two-way radio system meets this requirement; (5) Each brake shoe or pad is securely fastened and...

  1. All projects related to | Page 238 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2015-03-31

    End Date: March 31, 2015. Topic: CONFLICTS, CAPITAL MOVEMENTS, STATE, Economic and social development, MILITARY ACTIVITY. Region: Burundi, Democratic Republic of the Congo, Ethiopia, Kenya, Rwanda, Somalia, South Sudan, Uganda, North of Sahara, South of Sahara. Program: Governance and Justice.

  2. Dicty_cDB: SSL238 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available AC109618 |AC109618.4 Mus musculus clone RP23-478L3, WORKING DRAFT SEQUENCE, 16 ordered pieces. 50 0.008 1 AC113294...AC113294 |AC113294.3 Mus musculus clone RP23-419I1, WORKING DRAFT SEQUENCE, 22 unordered pieces. 50 0.008 1...genomic DNA, chromosome 1p36.2-p36 clone:dJ266I16, WORKING DRAFT SEQUENCE, 6 unordered pieces. 50 0.008 1...|AC096104.6 Rattus norvegicus clone CH230-27J15, WORKING DRAFT SEQUENCE, 1 ordered piece. 50 0.008 1 AC131941...AC101715 |AC101715.4 Mus musculus clone RP23-283P17, WORKING DRAFT SEQUENCE, 5 unordered pieces. 50 0.008 1

  3. Dicty_cDB: CHQ238 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available CTTTGCATTACTCTCCTC AAGCTCA sequence update 2002.10.25 Translated Amino Acid sequence vnk*kkkkkikknfxrf*KGXVL...A Translated Amino Acid sequence (All Frames) Frame A: vnk*kkkkkikknfxrf*KGXVLIKKKKXPLFFFFKKKXKIKKK--- ---RK

  4. Odontogenic tumors: clinical and pathology study of 238 cases

    OpenAIRE

    Rafael Linard Avelar; Antonio Azoubel Antunes; Thiago de Santana Santos; Emanuel Sávio de Souza Andrade; Edwaldo Dourado

    2008-01-01

    Os tumores odontogênicos são neoplasias que se desenvolvem exclusivamente nos ossos gnáticos, originando-se dos tecidos odontogênicos por proliferação de tecido epitelial, mesenquimal ou ambos. OBJETIVO: Avaliar a incidência de tumores odontogênicos em determinada instituição e comparar com outros estudos da literatura mundial. FORMA DE ESTUDO: Estudo de coorte transversal. MATERIAL E MÉTODO: O material do estudo foi levantado a partir dos registros de pacientes com tumores odontogênicos, no ...

  5. Dicty_cDB: SHB238 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available SLTIVDTQT LTCSAPPGSGIKNAVSFMVKDAESKLSPPLFLDYSPPTIMSSTSVKQVEGGQVTIYGTNF ENTLITVNVGSKSCEDVSVIDSTKLTCSI...SLTIVDTQT LTCSAPPGSGIKNAVSFMVKDAESKLSPPLFLDYSPPTIMSSTSVKQVEGGQVTIYGTNF ENTLITVNVGSKSCEDVSVIDSTKLTCSI

  6. P2-38: What Gives a Face its Race?

    Directory of Open Access Journals (Sweden)

    Wonmo Jung

    2012-10-01

    Full Text Available By biological criteria, human “races” do not exist (e.g., Cosmides et al., 2003. Nevertheless, every-day life and research from various fields show that we robustly and reliably perceive humans as belonging to different race groups. Here, we investigate the bases for our quick and easy judgments, by measuring the influence of manipulated facial features on race classification. Asian and Caucasian faces of our 3-dimensional face database (http://faces.kyb.tuebingen.mpg.de were paired according to sex, age, and overall appearance. With these Asian-Caucasian face pairs we created a variety of mixed-race faces, by exchanging facial features between both faces of a pair: eyes, nose, mouth, “outer” features, shape, or texture. Original and modified faces were shown in a simple race classification task. We tested 24 Westerners (Germany and 24 Easterners (South Korea. In both groups, eyes and texture were major determinants for race classification, followed by face shape, and then outer features, mouth, nose, which only had a weak influence on perceived face. Eastern participants classified Caucasian original faces better than Asian original faces, while Western participants were similarly good at classifying both races. Western participants—but not their Eastern counterparts—were less susceptible to eye, shape, and texture manipulations in other-race faces than in their own-race faces. A closer look at the data suggests that this effect mainly originates from differences in processing male and female faces in Western participants only. Our results provide more evidence of differences between observers from different cultural and ethnic backgrounds in face perception and processing.

  7. P2-38: What Gives a Face its Race?

    National Research Council Canada - National Science Library

    Jung, Wonmo; Armann, Regine G M; Bülthoff, Isabelle

    2012-01-01

    By biological criteria, human “races” do not exist (e.g., Cosmides et al., 2003). Nevertheless, every-day life and research from various fields show that we robustly and reliably perceive humans as belonging to different race groups...

  8. 49 CFR 238.403 - Crash energy management.

    Science.gov (United States)

    2010-10-01

    ... operator's cab in each power car; (2) A minimum of an additional 3 MJ shall be absorbed by the power car structure between the operator's cab and the first trailer car; and (3) The end of the first trailer car... resulting from dynamic forces transmitted to occupied volumes. (b) The design of each unit shall consist of...

  9. 238-IJBCS-Article- Dr Tsirinirindravo H L

    African Journals Online (AJOL)

    RHUMSIKI

    Micrococacées (Micrococcus luteus, Staphylococcus aureus). La sensibilité de Rhodococcus sp., Listeria monocytogenes, Listeria utelshi, Listeria ivanivii a été également remarquée. Les CMI de cet extrait vis-à-vis de Hafnia alvei, Micrococcus luteus, Staphylococcus aureus, et Listeria utelshi sont respectivement de 15,92.

  10. Aluminum Target Dissolution in Support of the Pu-238 Program

    Energy Technology Data Exchange (ETDEWEB)

    McFarlane, Joanna [ORNL; Benker, Dennis [ORNL; DePaoli, David W [ORNL; Felker, Leslie Kevin [ORNL; Mattus, Catherine H [ORNL

    2014-09-01

    Selection of an aluminum alloy for target cladding affects post-irradiation target dissolution and separations. Recent tests with aluminum alloy 6061 yielded greater than expected precipitation in the caustic dissolution step, forming up to 10 wt.% solids of aluminum hydroxides and aluminosilicates. We present a study to maximize dissolution of aluminum metal alloy, along with silicon, magnesium, and copper impurities, through control of temperature, the rate of reagent addition, and incubation time. Aluminum phase transformations have been identified as a function of time and temperature, using X-ray diffraction. Solutions have been analyzed using wet chemical methods and X-ray fluorescence. These data have been compared with published calculations of aluminum phase diagrams. Temperature logging during the transients has been investigated as a means to generate kinetic and mass transport data on the dissolution process. Approaches are given to enhance the dissolution of aluminum and aluminosilicate phases in caustic solution.

  11. Dicty_cDB: SSG238 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 2e-21 2 BU044708 |BU044708.1 PP_LEa0020E04f Peach developing fruit mesocarp Prunus persica cDNA clone PP_LEa0020E04f...2e-10 2 BU040616 |BU040616.1 PP_LEa0006L02f Peach developing fruit mesocarp Prunus persica cDNA clone PP_LEa0006L02f

  12. Dicty_cDB: CFE238 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available NKVDLGESKSADKKLTTVHQNCITSIVPFKSVGGVV S*fqyxwfrw*hcrmacksx*s*k Translated Amino Ac...LFQNKVDLGESKSADKKLTTVHQNCITSIVPFKSVGGVV S*fqyxwfrw*hcrmacksx*s*k Homology vs CSM-cDNA Score E Sequences prod

  13. 238-IJBCS-Article- Dr Tsirinirindravo H L

    African Journals Online (AJOL)

    RHUMSIKI

    Dans l'optique de rechercher les antibiotiques d'origine naturelle, l'activité antibactérienne des extraits de feuilles de Dalechampia clematidifolia sur certaines bactéries a été étudiée. Dalechampia clematidifolia est une euphorbe endémique de Madagascar ayant de nombreuses vertus. Elle est utilisée en pharmacopée.

  14. A retrospective study of californium-252 neutron brachytherapy combined with EBRT versus 3D-CRT in the treatment of esophageal squamous cell cancer.

    Science.gov (United States)

    Wang, Qifeng; Li, Tao; Lang, Jinyi; Wang, Jie; Wang, Jian; Liu, Huiming; Jia, Xitang; Liu, Bo; Wang, C-K Chris

    2015-10-24

    We conducted a retrospective analysis on 884 patients who were diagnosed with esophageal squamous cell carcinoma (ESCC) and treated with either the neutron brachytherapy in combination with external beam radiotherapy (NBT + EBRT) or 3-dimensional conformal radiation therapy (3D-CRT) to determine the differences in efficacy and morbidity between the two treatment groups. The 884 ESCC patients treated with either NBT + EBRT or 3D-CRT between 2002 and 2012 were retrospectively reviewed and analyzed. Multivariable Cox regression was used to compare oncologic outcomes of the two groups of patients in the context of other clinically relevant variables. The acute and chronic toxicities associated with the two groups were compared using Fisher exact and log-rank tests, respectively. Among the 884 patients, 545 received NBT + EBRT and 339 received 3D-CRT (i.e. EBRT-only). The age range is 39-95 years (median 66). The follow-up time range is 3-145 months (median 32). The analysis shows that the NBT + EBRT group has higher overall survival rate and local control rate than that of the 3D-CRT group. The acute toxicity effects were acceptable for both groups of patients with the NBT + EBRT group showing higher rates of leukopenia and thrombocytopenia and the 3D-CRT group showing higher rates on fistula and massive bleeding. The patients treated with NBT + EBRT showed better oncologic outcomes than those treated with 3D-CRT. The toxicity effects were acceptable for both groups with the NBT + EBRT group showing higher rates on the acute effects and the 3D-CRT group showing higher rates on the late effects.

  15. Accurate determination of Curium and Californium isotopic ratios by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) in 248Cm samples for transmutation studies

    Energy Technology Data Exchange (ETDEWEB)

    Gourgiotis, A.; Isnard, H.; Aubert, M.; Dupont, E.; AlMahamid, I.; Cassette, P.; Panebianco, S.; Letourneau, A.; Chartier, F.; Tian, G.; Rao, L.; Lukens, W.

    2011-02-01

    The French Atomic Energy Commission has carried out several experiments including the mini-INCA (INcineration of Actinides) project for the study of minor-actinide transmutation processes in high intensity thermal neutron fluxes, in view of proposing solutions to reduce the radiotoxicity of long-lived nuclear wastes. In this context, a Cm sample enriched in {sup 248}Cm ({approx}97 %) was irradiated in thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). This work describes a quadrupole ICP-MS (ICP-QMS) analytical procedure for precise and accurate isotopic composition determination of Cm before sample irradiation and of Cm and Cf after sample irradiation. The factors that affect the accuracy and reproducibility of isotopic ratio measurements by ICP-QMS, such as peak centre correction, detector dead time, mass bias, abundance sensitivity and hydrides formation, instrumental background, and memory blank were carefully evaluated and corrected. Uncertainties of the isotopic ratios, taking into account internal precision of isotope ratio measurements, peak tailing, and hydrides formations ranged from 0.3% to 1.3%. This uncertainties range is quite acceptable for the nuclear data to be used in transmutation studies.

  16. Radiological Characterization Technical Report on Californium-252 Sealed Source Transuranic Debris Waste for the Off-Site Source Recovery Project at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-04-24

    This document describes the development and approach for the radiological characterization of Cf-252 sealed sources for shipment to the Waste Isolation Pilot Plant. The report combines information on the nuclear material content of each individual source (mass or activity and date of manufacture) with information and data on the radionuclide distributions within the originating nuclear material. This approach allows for complete and accurate characterization of the waste container without the need to take additional measurements. The radionuclide uncertainties, developed from acceptable knowledge (AK) information regarding the source material, are applied to the summed activities in the drum. The AK information used in the characterization of Cf-252 sealed sources has been qualified by the peer review process, which has been reviewed and accepted by the Environmental Protection Agency.

  17. Tumores odontogênicos: estudo clínico-patológico de 238 casos Odontogenic tumors: clinical and pathology study of 238 cases

    Directory of Open Access Journals (Sweden)

    Rafael Linard Avelar

    2008-10-01

    Full Text Available Os tumores odontogênicos são neoplasias que se desenvolvem exclusivamente nos ossos gnáticos, originando-se dos tecidos odontogênicos por proliferação de tecido epitelial, mesenquimal ou ambos. OBJETIVO: Avaliar a incidência de tumores odontogênicos em determinada instituição e comparar com outros estudos da literatura mundial. FORMA DE ESTUDO: Estudo de coorte transversal. MATERIAL E MÉTODO: O material do estudo foi levantado a partir dos registros de pacientes com tumores odontogênicos, no período de janeiro de 1992 a março de 2007 (15 anos. Foram incluídos os casos de pacientes que se enquadravam na Classificação Histológica da Organização Mundial de Saúde (OMS de 2005. Foram analisados os indicadores gênero, faixa etária, localização anatômica, tipo histológico e presença de sintomatologia. RESULTADOS: Os tumores odontogênicos constituíram 4,76% dentre todas as lesões biopsiadas dentro do período estudado. A idade média dos pacientes foi de 30,7 anos, 57% dos pacientes eram do gênero masculino. O tumor odontogênico ceratocístico foi o tipo histológico mais prevalente (30%, seguido do ameloblastoma (23,7%. Quanto à presença de sintomatologia, 75,7% dos casos apresentaram-se assintomáticos. CONCLUSÃO: Os tumores odontogênicos parecem ter discreta predileção pelo gênero feminino, segunda e terceira décadas de vida, sendo mais freqüentes na mandíbula e, na maioria dos casos apresentam-se assintomáticos.Odontogenic tumors are neoplasms that develops exclusively in the gnathic bones; they originate from odontogenic tissues, by epithelial or mesenchymal proliferation, or both. AIM: To evaluate the incidence of odontogenic tumors in a specific institution, and to compare these findings with other studies in the literature. STUDY FORMAT: A cross-sectional cohort retrospective study. MATERIAL AND METHOD: The sample was obtained from the files of patients with odontogenic tumors diagnosed between January 1992 and March 2007 (15 years. Cases in which the diagnosis could be adapted to the new World Health Organization (WHO of 2005 were included. Data such as gender, age, anatomical site, histological type and symptomatology were analyzed. RESULTS: Odontogenic tumors were 4.76% of all biopsied lesions within the studied period. The mean age was 30.7 years; 57% of the patients were male. The keratocystic odontogenic tumor was the most prevalent histological type (30%, followed by the ameloblastoma (23,7%. The rate of asymptomatic cases was 75.7%. CONCLUSION: Odontogenic tumors occurred more frequently in females, in the second and third decades of life, and more commonly in the mandible; most cases were asymptomatic.

  18. Formation of 238U16O and 238U18O observed by time-resolved emission spectroscopy subsequent to laser ablation

    Science.gov (United States)

    Weisz, David G.; Crowhurst, Jonathan C.; Siekhaus, Wigbert J.; Rose, Timothy P.; Koroglu, Batikan; Radousky, Harry B.; Zaug, Joseph M.; Armstrong, Michael R.; Isselhardt, Brett H.; Savina, Michael R.; Azer, Magdi; Finko, Mikhail S.; Curreli, Davide

    2017-07-01

    We have measured vibronic emission spectra of an oxide of uranium formed after laser ablation of the metal in gaseous oxygen. Specifically, we have measured the time-dependent relative intensity of a band located at approximately 593.6 nm in 16O2. This band grew in intensity relative to neighboring atomic features as a function time in an oxygen environment but was relatively invariant with time in argon. In addition, we have measured the spectral shift of this band in an 18O2 atmosphere. Based on this shift, and by comparison with earlier results obtained from free-jet expansion and laser excitation, we can confirm that the oxide in question is UO, consistent with recent reports based on laser ablation in 16O2 only.

  19. Effect of carbides on erosion resistance of 23-8-N steel

    Indian Academy of Sciences (India)

    ment in erosion resistance can be attributed to major changes in microstructure and the mechanical properties. The sig- nificant change in the microstructure is associated with the dissolution of carbides. In alloy system, the highest ero- sion resistance has been reported to be obtained either in the solution treated condition ...

  20. 49 CFR Appendix D to Part 238 - Requirements for External Fuel Tanks on Tier I Locomotives

    Science.gov (United States)

    2010-10-01

    ... plate of the fuel tank shall support a sudden loading of one-half the weight of the car body at a... (half the bumper area) at a height of thirty inches above the rail (standard DOT bumper height). (4...

  1. Transmutation of 129 I, 237 Np, 238 Pu, 239 Pu, and 241 Am using ...

    Indian Academy of Sciences (India)

    Target-blanket facility `Energy + Transmutation' was irradiated by proton beam extracted from the Nuclotron Accelerator in Laboratory of High Energies of Joint Institute for Nuclear Research in Dubna, Russia. Neutrons generated by the spallation reactions of 0.7, 1.0, 1.5 and 2 GeV protons and lead target interact with ...

  2. Page 1 238 S Kesavan 5. Conclusion It has been proved that non ...

    Indian Academy of Sciences (India)

    which has been used only to prove the existence of a solution via a priori estimates. Indeed this condition can be removed and replaced by any other which guarantees the existence of a non-singular solution of the homogenized problem alone. Then the method of this paper can be used to prove (without new hypotheses) ...

  3. Analysis of TPC Single Sextant U-238/U-235 Engineering In-Beam Data

    Energy Technology Data Exchange (ETDEWEB)

    Tony Hill

    2012-09-01

    The Time Projection Chamber is a collaborative effort to implement an innovative approach and deliver unprecedented fission measurements to DOE programs. This 4p- detector system will provide unrivaled 3-D data about the fission process. This TPC has been shipped and installed at LANSCE and is collecting further engineering data for the full system scale up next year.

  4. Determination of 238Pu, 239+240Pu and 241Am in air filters

    OpenAIRE

    Rzemek, Katarzyna; Czerwi?ski, Andrzej; O?ko, Jakub; Tymi?ska, Katarzyna; Dymecka, Ma?gorzata; Pliszczy?ski, Tomasz

    2016-01-01

    The aim of this work is to present the method for sequential plutonium and americium activity determination in air filters using chromatographic radionuclide separation and alpha spectrometry measurement. The developed method may be employed for the purposes of workplace monitoring and as an indicator of the need of introducing the individual monitoring as well as a useful complementation of individual monitoring. Basic parameters describing the developed method such as values of chemical rec...

  5. 48 CFR 552.238-72 - Identification of Products That Have Environmental Attributes.

    Science.gov (United States)

    2010-10-01

    ... that provide environmental benefits, excluding recovered materials and energy and water efficiency... (42 U.S.C. 6962(h)). Remanufactured means factory rebuilt to original specifications. Renewable energy means energy produced by solar, wind, geothermal, and biomass power. Renewable energy technology means...

  6. Distribution of U-235 and U-238 in food(II)

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Woo; Lee, Jeong Min; Oh, Hyun Kyun; Han, Man Joong [KORTIC, Taejon (Korea, Republic of)

    2004-02-15

    To accomplish the objective of this work, analyses of uranium concentration in 100 food samples (fruit and vegetables) were carried out. The surveillance results on uranium isotope concentrations in food of Korea will be used as a basis of estimating the annual effective dose to the public by uranium and a baseline data to establish a national recommend value for the protection from radiation of food.

  7. Transmutation of 129I, 237Np, 238Pu, 239Pu, and 241Am using ...

    Indian Academy of Sciences (India)

    1Joint Institute for Nuclear Research, Dubna near Moscow, 141 980 Russian Federation. 2Czech Academy of ... tween each two sections are slits into which experimental instruments and detectors are inserted. The side from where ... Simplified design of the 'Energy + Transmutation' assembly inside its shielding as used in ...

  8. 49 CFR 238.305 - Interior calendar day mechanical inspection of passenger cars.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Interior calendar day mechanical inspection of... Interior calendar day mechanical inspection of passenger cars. (a) Except as provided in paragraph (d) of this section, each passenger car shall receive an interior mechanical inspection at least once each...

  9. Effect of carbides on erosion resistance of 23-8-N steel

    Indian Academy of Sciences (India)

    Department of Metallurgical and Materials Engineering, Malaviya National Institute of Technology, Jaipur 302 017, India; Former Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Roorkee 247 667, India (Now at BRCM College of Engineering & Technology, Bahal 127 028, India) ...

  10. 49 CFR Appendix E to Part 238 - General Principles of Reliability-Based Maintenance Programs

    Science.gov (United States)

    2010-10-01

    ... altered only by basic changes in the design. Safety consequences can, in nearly all cases, be reduced to... that a failure has occurred); (3) The visibility of reduced resistance to failure (evidence that a..., the operating organization must be prepared to collect and respond to real data throughout the...

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

    Science.gov (United States)

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

    2012-08-01

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

  12. Effect of glucosamine supplementation on litter size in a commercial setting, NPB project #14-238

    Science.gov (United States)

    Litter size is influenced by ovulation rate, fertilization rate, embryo mortality and uterine capacity. Of these, the most limiting factor is uterine capacity, because increased ovulation rate results in increased number of embryos on day 30 of gestation, but this advantage is lost during later gest...

  13. 49 CFR 238.303 - Exterior calendar day mechanical inspection of passenger equipment.

    Science.gov (United States)

    2010-10-01

    ... pneumatic suspension system component inflates or deflates, as applicable, correctly and otherwise operates... to prevent the pin from falling out of place in case of breakage. (5) The suspension system... motor suspension lug, equalizer, hanger, gib, or pin is not cracked or broken; and (iii) The truck frame...

  14. 238 Effectiveness of Sinus Surgery for Lower Airway Disease

    OpenAIRE

    Kagoya, Ryoji; Shinogami, Masanobu; Mouri, Hirohisa; Suzuki, Sayaka; Nakanishi, Wakako; Yoshinami, Hiroyoshi

    2012-01-01

    Background Upper respiratory illness can adversely impact the lower airway. This study aimed to evaluate the relationship between clinical background and improvement in the lower airway after surgery for treatment of chronic rhinosinusitis. Methods A total of 22 patients with chronic rhinosinusitis surgically treated between January 2010 and February 2011 were included in the study. The presence or absence of asthma and peripheral blood eosinophils count were examined for all patients in addi...

  15. SU-E-T-238: Deriving Electron Contamination Spectra From Pure and Clinical Photon Beams

    Energy Technology Data Exchange (ETDEWEB)

    Smit, C; Plessis, F du [University of the Free State, Bloemfontein, Free State (South Africa)

    2015-06-15

    Purpose: To extract the electron contamination energy spectra for an Elekta Precise Linac, based on pure photon and measured clinical beam percentage depth dose data. And to include this as an additional source in isource 4 in DOSXYZnrc. Methods: A pure photon beam was simulated for the Linac using isource 4 in the DOSXYZnrc Monte Carlo (MC) code. Percentage depth dose (PDD) data were extracted afterwards for a range of field sizes (FS). These simulated dose data were compared to actual measured dose PDD data, with the data normalized at 10 cm depth. The resulting PDD data resembled the electron contamination depth dose. Since the dose fall-off is a strictly decreasing function, a method was adopted to derive the contamination electron spectrum. Afterwards this spectrum was used in a DOSXYZnrc MC simulation run to verify that the original electron depth dose could be replicated. Results: Various square aperture FS’s for 6, 8 and 15 megavolt (MV) photon beams were modeled, simulated and compared to their respective actual measured PDD data. As FS increased, simulated pure photon depth-dose profiles shifted deeper, thus requiring electron contamination to increase the surface dose. The percentage of electron weight increased with increase in FS. For a FS of 15×15 cm{sup 2}, the percentage electron weight is 0.1%, 0.2% and 0.4% for 6, 8 and 15 MV beams respectively. Conclusion: From the PDD results obtained, an additional electron contamination source was added to the photon source model so that simulation and measured PDD data could match within 2 % / 2 mm gamma-index criteria. The improved source model could assure more accurate simulations of surface doses. This research project was funded by the South African Medical Research Council (MRC) with funds from National Treasury under its Economic Competitiveness and Support package.

  16. SU-E-T-238: Monte Carlo Estimation of Cerenkov Dose for Photo-Dynamic Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chibani, O; Price, R; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States); Eldib, A [Fox Chase Cancer Center, Philadelphia, PA (United States); University Cairo (Egypt); Mora, G [de Lisboa, Codex, Lisboa (Portugal)

    2014-06-01

    Purpose: Estimation of Cerenkov dose from high-energy megavoltage photon and electron beams in tissue and its impact on the radiosensitization using Protoporphyrine IX (PpIX) for tumor targeting enhancement in radiotherapy. Methods: The GEPTS Monte Carlo code is used to generate dose distributions from 18MV Varian photon beam and generic high-energy (45-MV) photon and (45-MeV) electron beams in a voxel-based tissueequivalent phantom. In addition to calculating the ionization dose, the code scores Cerenkov energy released in the wavelength range 375–425 nm corresponding to the pick of the PpIX absorption spectrum (Fig. 1) using the Frank-Tamm formula. Results: The simulations shows that the produced Cerenkov dose suitable for activating PpIX is 4000 to 5500 times lower than the overall radiation dose for all considered beams (18MV, 45 MV and 45 MeV). These results were contradictory to the recent experimental studies by Axelsson et al. (Med. Phys. 38 (2011) p 4127), where Cerenkov dose was reported to be only two orders of magnitude lower than the radiation dose. Note that our simulation results can be corroborated by a simple model where the Frank and Tamm formula is applied for electrons with 2 MeV/cm stopping power generating Cerenkov photons in the 375–425 nm range and assuming these photons have less than 1mm penetration in tissue. Conclusion: The Cerenkov dose generated by high-energy photon and electron beams may produce minimal clinical effect in comparison with the photon fluence (or dose) commonly used for photo-dynamic therapy. At the present time, it is unclear whether Cerenkov radiation is a significant contributor to the recently observed tumor regression for patients receiving radiotherapy and PpIX versus patients receiving radiotherapy only. The ongoing study will include animal experimentation and investigation of dose rate effects on PpIX response.

  17. Scavenging Phenomenon Elucidated from 234Th/238U Disequilibrium in Surface Water of the Taiwan Strait

    Directory of Open Access Journals (Sweden)

    Ching-Ling Wei

    2010-01-01

    Full Text Available Concentrations of dissolved (234Thd and particulate (234Thp 234Th in surface water at 38 stations in the Taiwan Strait were determined for samples collected in May 2006. The spatial distribution of 234Th in the Taiwan Strait is controlled by advective input of Kuroshio Branch Water via the Peng-Hu Channel and fast removal due to the high input of riverine particulates from the Cho-Sui River. A scavenging model involving physical transport was applied to the 234Thd and 234Thp data to estimate scavenging and removal rates of 234Th. Estimated scavenging rate ranges from 32 to 703 dpm m-3 d-1 and the removal rate ranges from 24 to 560 dpm m-3 d-1. Using 234Th as a proxy of particulate organic carbon, we estimate that the removal rate of POC from surface water of the Taiwan Strait ranges from 0.3 ± 1.5 mmol-C m-3 d-1 off southwestern Taiwan to 10.2 ± 3.5 mmol-C m-3 d-1 in the central Taiwan Strait.

  18. 28 CFR 2.38 - Community supervision by U.S. Probation Officers.

    Science.gov (United States)

    2010-07-01

    ...) of title 18 of the U.S. Code, U.S. Probation Officers shall provide such parole services as the Commission may request. In conformity with the foregoing, probation officers function as parole officers and... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Community supervision by U.S. Probation...

  19. Toxicity Reduction of Reactive Red Dye-238 Using Advanced Oxidation Process by Solar Energy

    OpenAIRE

    Riyad Al-Anbari; Abdul Hamed Al-Obaidy; Eman Abd

    2017-01-01

    Decolorization of red azo dye (Cibacron Red FN-R) from synthetic wastewater has been investigated as a function of solar advanced oxidation process. The photocatalytic activity using ZnO as a photocatalysis has been estimated. Different parameters affected the removal efficiency, including pH of the solution, initial dye concentration and H2O2 concentration were evaluated to find out the optimum value of these parameters. The results proved that the optimal pH value was 8 and the most efficie...

  20. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Science.gov (United States)

    2010-10-01

    ... defect; (vi) The destination of the equipment where it will be repaired; and (vii) The signature, if... employee manning the handbrake; and (iii) Appropriate speed restrictions shall be placed on the train by a...

  1. Charge stripping of ^{238}U ion beam by helium gas stripper

    National Research Council Canada - National Science Library

    Imao, H; Okuno, H; Kuboki, H; Yokouchi, S; Fukunishi, N; Kamigaito, O; Hasebe, H; Watanabe, T; Watanabe, Y; Kase, M; Yano, Y

    2012-01-01

    Development of a nondestructive, efficient electric-charge-stripping method is a key requirement for next-generation high-intensity heavy-ion accelerators such as the RIKEN Radioactive-Isotope Beam Factory...

  2. 48 CFR 552.238-71 - Submission and Distribution of Authorized FSS Schedule Pricelists.

    Science.gov (United States)

    2010-10-01

    ... through the on-line Multiple Award Schedule electronic data base. (d) The Contractor shall make all of the... Authorized FSS Schedule Pricelists (SEP 1999) (a) Definition. For the purposes of this clause, the Mailing... instructions for the electronic submission with the award notification. Some structured data entry in a...

  3. Yeast Interacting Proteins Database: YDL238C, YBR284W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available roducing xanthine and ammonia from guanine; activity is low in exponentially-growing cultures but expression...uanine; activity is low in exponentially-growing cultures but expression is increased in post-diauxic and st

  4. Разработка Култукского сейсмопрогностического полигона: вариации ( 234U/ 238U) и 87Sr/ 86Sr в подземных водах из активных разломов западного побережья Байкала

    OpenAIRE

    РАССКАЗОВ СЕРГЕЙ ВАСИЛЬЕВИЧ; ЧЕБЫКИН ЕВГЕНИЙ ПАВЛОВИЧ; ИЛЬЯСОВА АЙГУЛЬ МАРАТОВНА; ВОДНЕВА ЕЛЕНА НИКОЛАЕВНА; ЧУВАШОВА ИРИНА СЕРГЕЕВНА; БОРНЯКОВ СЕРГЕЙ АЛЕКСАНДРОВИЧ; СЕМИНСКИЙ АЛЕКСАНДР КОНСТАНТИНОВИЧ; СНОПКОВ СЕРГЕЙ ВИКТОРОВИЧ; ЧЕЧЕЛЬНИЦКИЙ ВЛАДИМИР ВАСИЛЬЕВИЧ; ГИЛЁВА НАДЕЖДА АЛЕКСЕЕВНА

    2015-01-01

    Введение. Для отслеживания текущих деформаций в зонах активных разломов перспективны определения ( 234U/ 238U) в подземных водах (скобки обозначают единицы активности). Циклическое равновесие отношения активностей 234U/ 238U≈( 234U/ 238U)≈γ≈1 соответствует атомному отношению ≈5.47×10 -5. Вариации этого параметра могут быть обусловлены эффектом Чалова-Чердынцева обогащением подземных вод нуклидом 234U в результате деформаций пород [ Cherdyntsev, 1969, 1973; Chalov, 1975; Chalov et al., 1990; F...

  5. Pu236(n,f) , Pu237(n,f) , and Pu238(n,f) cross sections deduced from (p,t) , (p,d) , and (p,p') surrogate reactions

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, R. O. [Univ. of Richmond, VA (United States); Beausang, C. W. [Univ. of Richmond, VA (United States); Ross, T. J. [Univ. of Richmond, VA (United States); Burke, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Casperson, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cooper, N. [Yale Univ., New Haven, CT (United States); Escher, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gell, K. [Univ. of Richmond, VA (United States); Good, E. [Univ. of Richmond, VA (United States); Humby, P. [Yale Univ., New Haven, CT (United States); McCleskey, M. [Texas A & M Univ., College Station, TX (United States); Saastimoinen, A. [Texas A & M Univ., College Station, TX (United States); Tarlow, T. D. [Univ. of Richmond, VA (United States); Thompson, I. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-07-01

    The Pu236(n,f), Pu237(n,f) and Pu238(n,f) cross sections have been inferred by utilizing the surrogate ratio method. Targets of Pu239 and U235 were bombarded with 28.5-MeV protons, and the light ion recoils, as well as fission fragments, were detected using the STARS detector array at the K150 Cyclotron at the Texas A&M cyclotron facility. The (p, tf) reaction on Pu239 and U235 targets was used to deduce the σ (Pu236(n,f))/σ(U232(n,f)) ratio, and the Pu236(n,f) cross section was subsequently determined for En=0.5–7.5 MeV. Similarly, the (p,df) reaction on the same two targets was used to deduce the σ(Pu237(n,f))/σ(U233(n,f)) ratio, and the Pu237(n,f) cross section was extracted in the energy range En=0.5–7 MeV. The Pu238(n,f) cross section was also deduced by utilizing the (p,p') reaction channel on the same targets. There is good agreement with the recent ENDF/B-VII.1 evaluated cross section data for Pu238(n,f) in the range En=0.5–10.5 MeV and for Pu237(n,f) in the range En=0.5–7 MeV; however, the Pu236(n,f) cross section deduced in the present work is higher than the evaluation between 2 and 7 MeV.

  6. Report to the DOE nuclear data committee. [EV RANGE 10-100; CROSS SECTIONS; PHOTONEUTRONS; NEUTRONS; GAMMA RADIATION; COUPLED CHANNEL THEORY; DIFFERENTIAL CROSS SECTIONS; MEV RANGE 01-10; ; CAPTURE; GAMMA SPECTRA; THERMAL NEUTRONS; COMPUTER CALCULATIONS; DECAY; FISSION PRODUCTS; FISSION YIELD; SHELL MODELS; NUCLEAR DATA COLLECTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Struble, G.L.; Haight, R.C.

    1981-03-01

    Topics covered include: studies of (n, charged particle) reactions with 14 to 15 MeV neutrons; photoneutron cross sections for /sup 15/N; neutron radiative capture; Lane-model analysis of (p,p) and (n,n) scattering on the even tin isotopes; neutron scattering cross sections for /sup 181/Ta, /sup 197/Au, /sup 209/Bi, /sup 232/Th, and /sup 238/U inferred from proton scattering and charge exchange cross sections; neutron-induced fission cross sections of /sup 245/Cm and /sup 242/Am; fission neutron multiplicities for /sup 245/Cm and /sup 242/Am; the transport of 14 MeV neutrons through heavy materials 150 < A < 208; /sup 249/Cm energy levels from measurement of thermal neutron capture gamma rays; /sup 231/Th energy levels from neutron capture gamma ray and conversion electron spectroscopy; new measurements of conversion electron binding energies in berkelium and californium; nuclear level densities; relative importance of statistical vs. valence neutron capture in the mass-90 region; determination of properties of short-lived fission products; fission yield of /sup 87/Br and /sup 137/I from 15 nuclei ranging from /sup 232/Th to /sup 249/Cf; evaluation of charged particle data for the ECPL library; evaluation of secondary charged-particle energy and angular distributions for ENDL; and evaluated nuclear structure libraries derived from the table of isotopes. (GHT)

  7. Исследование фракционирования изотопов урана (234U, 238U) в процессе образования кристаллов льда

    OpenAIRE

    ЯКОВЛЕВ Е.Ю.; КИСЕЛЁВ Г.П.; ДРУЖИНИН С.В.; ЗЫКОВ С.Б.

    2016-01-01

    С момента открытия явления фракционирования четных изотопов урана (эффект Чердынцева-Чалова) среди ряда исследователей сложилось устойчивое убеждение, что разделения изотопной пары урана 234U и 238U в минеральных системах не происходит, и фракционирование возможно только при переходе из твердой фазы в жидкую по причине различной подвижности изотопов. Наблюдаемые избытки изотопа 234U в суммарном уране различных минералов и горных пород, возраст которых значительно превышает период установления...

  8. Comparison of measurements and calculations of fuel for different structures in the libraries of effective sections (44 groups/238 groups); Comparacion de medidas y calculos de combustibles para diversas estructuras en las librerias de secciones eficaces (44 grupos/238 grupos)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rivada, A.; Tore, C.

    2013-07-01

    The study was conducted for the use of the sections effective in 44 groups, based on the libraries of effective sections ENDF/b-v, for the calculation of the isotopy of the spent fuel. These effective sections have been developed to be used in the system codes SCALE for the analysis the fresh nuclear fuel as the spent and their radioactive waste.

  9. Domain interactions within the Ski2/3/8 complex and between the Ski complex and Ski7p

    OpenAIRE

    WANG, LINGNA; LEWIS, MARC S.; JOHNSON, ARLEN W.

    2005-01-01

    The Ski complex (composed of Ski3p, Ski8p, and the DEVH ATPase Ski2p) is a central component of the 3′–5′ cytoplasmic mRNA degradation pathway in yeast. Although the proteins of the complex interact with each other as well as with Ski7p to mediate degradation by exosome, a 3′-exonuclease complex, the nature of these interactions is not well understood. Here we explore interactions within the Ski complex and between the Ski complex and Ski7p using a directed two-hybrid approach combined with c...

  10. Book Review: Petrakis, Panagiotis E. Culture, Growth And Economic Policy. Berlin, Heidelberg: Springer-Verlag, 2014. 238 PP.

    Directory of Open Access Journals (Sweden)

    Andy Bangkit Setiawan

    2016-01-01

    Full Text Available Lately, Indonesian exposed by a service called Go-Jek. Go-Jek is a multimedia based ojek (motorcycle taxi which is launched in some cities in Indonesia, which the costumers can only use specific application provided by Go-Jek company to call the ojek riders who will take them to their destinations. Even amount of the cost charged can be shown by the costumers at the moment they order without any bargain with the riders like the conventional ojek. By all means, this facility cuts off all inefficiency, which felt by ojek costumers and riders. However, resistance arises from some particular people who work as conventional ojek riders. Even at some places violence done by conventional ojek riders to Go-Jek riders, does happen.

  11. Commissioning the NIFFTE Time Projection Chamber: Towards the 238U / 235U (n, f) Cross-section Ratio

    Science.gov (United States)

    Meharchand, R.; Asner, D. M.; Baker, R. G.; Bundgaard, J.; Burgett, E.; Cunningham, M.; Deaven, J.; Duke, D. L.; Greife, U.; Grimes, S.; Heffner, M.; Hill, T.; Isenhower, D.; Klay, J. L.; Kleinrath, V.; Kornilov, N.; Laptev, A. B.; Loveland, W.; Massey, T. N.; Qu, H.; Ruz, J.; Sangiorgio, S.; Seilhan, B.; Snyder, L.; Stave, S.; Tatishvili, G.; Thornton, R. T.; Tovesson, F.; Towell, D.; Towell, R. S.; Watson, S.; Wendt, B.; Wood, L.

    2014-05-01

    The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration is developing a Time Projection Chamber (TPC) to measure neutron-induced fission cross sections with unprecedented accuracy. Modifying TPC technology for nuclear physics applications is a challenging endeavor, and frequent testing and evaluation is required to ensure that all components are behaving as expected. In-beam tests of the NIFFTE TPC at the Los Alamos Neutron Science Center (LAN-SCE) commenced in 2010. An overview of the NIFFTE TPC experiments performed at LANSCE will be presented, along with preliminary performance results.

  12. Radiolytic oxidation of UO{sub 2} pellets doped with alpha-emitters ({sup 238/239}Pu)

    Energy Technology Data Exchange (ETDEWEB)

    Muzeau, B. [Commissariat a l' Energie Atomique, Rhone Valley Research Center DTCD/SECM/LMPA, BP 17 171, 30207 Bagnols-sur-Ceze Cedex (France); Jegou, C. [Commissariat a l' Energie Atomique, Rhone Valley Research Center DTCD/SECM/LMPA, BP 17 171, 30207 Bagnols-sur-Ceze Cedex (France)], E-mail: christophe.jegou@cea.fr; Delaunay, F. [Commissariat a l' Energie Atomique, Valduc Research Center, 21120 Is-sur-Tille (France); Broudic, V. [Commissariat a l' Energie Atomique, Rhone Valley Research Center DTCD/SECM/LMPA, BP 17 171, 30207 Bagnols-sur-Ceze Cedex (France); Brevet, A. [Commissariat a l' Energie Atomique, Valduc Research Center, 21120 Is-sur-Tille (France); Catalette, H. [Electricite de France, Les Renardieres Research Center, Route de Sens Ecuelles, 77250 Moret-sur-Loing (France); Simoni, E. [Institut de Physique Nucleaire, Bat. 100, 91406 Orsay Cedex (France); Corbel, C. [Laboratoire des Solides Irradies, UMR 7642-CNRS-CEA-Ecole Polytechnique, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2009-01-07

    To assess the impact of alpha radiolysis of water on the oxidative dissolution of UO{sub 2} under anoxic conditions, two series of plutonium-doped samples (specific alpha activity 385 and 18 MBqg{sub UO{sub 2}}{sup -1}) were fabricated, characterized and leached in water of varying complexity (pure water, carbonated water, dissolved hydrogen). Given the very high reactivity of these samples in the presence of air and in order to minimize any prior surface oxidation, a strict experimental protocol was developed based on high-temperature annealing in Ar + 4% H{sub 2} with preleaching cycles. Failure to follow this protocol prevents absolute quantification of oxidation of the UO{sub 2} surface by water radiolysis in solutions. Preoxidation of the pellet surface can lead to uranium release in solution that is dependent on the alpha particle flux, revealing initial oxidation by radiolysis in air including potential traces of water. This makes difficult the accurate quantification of the radiolytic oxidation in water solutions. Controlling the initial surface condition of the samples finally allowed us to demonstrate that radiolytic oxidation in water-saturated media is governed by several threshold effects for which the main parameters are the sample alpha activity and the hydrogen concentration.

  13. Fission Product Yields from 232Th, 238U, and 235U Using 14 MeV Neutrons

    Science.gov (United States)

    Pierson, B. D.; Greenwood, L. R.; Flaska, M.; Pozzi, S. A.

    2017-01-01

    Neutron-induced fission yield studies using deuterium-tritium fusion-produced 14 MeV neutrons have not yet directly measured fission yields from fission products with half-lives on the order of seconds (far from the line of nuclear stability). Fundamental data of this nature are important for improving and validating the current models of the nuclear fission process. Cyclic neutron activation analysis (CNAA) was performed on three actinide targets-thorium-oxide, depleted uranium metal, and highly enriched uranium metal-at the University of Michigan's Neutron Science Laboratory (UM-NSL) using a pneumatic system and Thermo-Scientific D711 accelerator-based fusion neutron generator. This was done to measure the fission yields of short-lived fission products and to examine the differences between the delayed fission product signatures of the three actinides. The measured data were compared against previously published results for 89Kr, -90, and -92 and 138Xe, -139, and -140. The average percent deviation of the measured values from the Evaluated Nuclear Data Files VII.1 (ENDF/B-VII.1) for thorium, depleted-uranium, and highly-enriched uranium were -10.2%, 4.5%, and -12.9%, respectively. In addition to the measurements of the six known fission products, 23 new fission yield measurements from 84As to 146La are presented.

  14. Fission Product Yields from {sup 232}Th, {sup 238}U, and {sup 235}U Using 14 MeV Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, B.D., E-mail: bpnuke@umich.edu [Department of Nuclear Engineering Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd., Ann Arbor, MI 48109 (United States); Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States); Greenwood, L.R. [Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States); Flaska, M. [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, 227 Reber Bldg., University Park, PA 16802 (United States); Pozzi, S.A. [Department of Nuclear Engineering Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd., Ann Arbor, MI 48109 (United States)

    2017-01-15

    Neutron-induced fission yield studies using deuterium-tritium fusion-produced 14 MeV neutrons have not yet directly measured fission yields from fission products with half-lives on the order of seconds (far from the line of nuclear stability). Fundamental data of this nature are important for improving and validating the current models of the nuclear fission process. Cyclic neutron activation analysis (CNAA) was performed on three actinide targets–thorium-oxide, depleted uranium metal, and highly enriched uranium metal–at the University of Michigan's Neutron Science Laboratory (UM-NSL) using a pneumatic system and Thermo-Scientific D711 accelerator-based fusion neutron generator. This was done to measure the fission yields of short-lived fission products and to examine the differences between the delayed fission product signatures of the three actinides. The measured data were compared against previously published results for {sup 89}Kr, −90, and −92 and {sup 138}Xe, −139, and −140. The average percent deviation of the measured values from the Evaluated Nuclear Data Files VII.1 (ENDF/B-VII.1) for thorium, depleted-uranium, and highly-enriched uranium were −10.2%, 4.5%, and −12.9%, respectively. In addition to the measurements of the six known fission products, 23 new fission yield measurements from {sup 84}As to {sup 146}La are presented.

  15. Simulated PUREX Solvent Extraction Experiments Using {sup 238}U, {sup 239}Np and {sup 85}Sr Solution

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju hyeong; Park, Kwangheon; Kim, Tae hoon; Park, Hyoung gyu; Kim, Jisu [Kyunghee University, Yongin (Korea, Republic of); Song, Hyuk jin [Dongguk University, Gyeongju (Korea, Republic of); Lee, Chan ki; Kang, Do kyu; Jeong, Hyeon jun [UNIST, Ulsan (Korea, Republic of)

    2016-10-15

    PUREX (plutonium uranium redox extraction) is an aqueous reprocessing method that separates U from spent nuclear fuel using a solvent extraction process. In solvent extraction process, predicting the behavior of U, MA (minor actinides) and TRU (transuranic elements) is important, because efficiency of U recovery is determined by their combined behavior. In this study, PUREX-simulated aqueous solution was prepared by varying [HNO{sub 3}] as 0.1 M, 1 M, and 5 M, to measure U extraction behavior. It is hard to determine the optimum nitric acid concentration for extraction of only uranium because the mechanism is very complicated. It can’t be calculated by mathematics, but, in this experiment, only 3 points of nitric acid concentration exist. Anyway, the optimum point is at 0.5 M of nitric acid. Therefore, estimation of the optimum point is not correct. If more accurate estimation should be needed, more experiments are needed. How to increase the separation efficiency of uranium and plutonium is very important for PUREX process. However, in real spent nuclear fuel, there are many nuclides, about 50 elements of FPs and MAs. The mechanism of solvent extraction is more complicated, as elements participated in reaction are increased. Therefore, understanding the behaviors of FPs and MAs during the solvent extraction is very important. The highest separation efficiency can be obtained and designed, when we make the appropriate modeling of the solvent extraction process in the view of engineering.

  16. 49 CFR Appendix B to Part 238 - Test Methods and Performance Criteria for the Flammability and Smoke Emission Characteristics of...

    Science.gov (United States)

    2010-10-01

    ... generation. These portions include equipment carrying portions of a vehicle's roof and the interior structure... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may inspect a... demonstrated to be permanent after dynamic testing according to ASTM D 3574-95, Test I 2 (Dynamic Fatigue Test...

  17. Ukraine Against Herself: To Be Euro-Atlantic, Eurasian, or Neutral? (Strategic Forum, Number 238, February 2009)

    National Research Council Canada - National Science Library

    Simon, Jeffrey

    2009-01-01

    ... (Russia and the Commonwealth of Independent States). During the 1990s, when the European Union and NATO were focused on Central Europe and Russia was politically down and economically weak, Ukraine was able to have it...

  18. Epidemiological profile of elderly women with burning mouth symptoms - doi:10.5020/18061230.2011.p238

    Directory of Open Access Journals (Sweden)

    Maria Vieira de Lima Saintrain

    2012-01-01

    Full Text Available Objective: To determine the epidemiological profile of elderly women with burning mouth symptoms. Methods: A cross sectional, quantitative, exploratory and descriptive study conducted in two phases: a determining the prevalence of burning mouth symptoms among 263 elderly women aged between 60 and 83 years who attended six public municipal community centers in Fortaleza-CE, Brazil, b defining the epidemiological profile of respondents with burning mouth symptoms, through the variables: self-reported diseases, salivary flow, use of medications, dental prosthesis and oral hygiene habits. Data were organized by the Statistical Package for Social Sciences - SPSS version 15. Results: The prevalence of burning mouth symptoms in the group was 19% (n=50. Of these, 41 (82.0% reported the manifestation of the symptoms as a scalding sensation. Regarding the occurrence, the most referred sites were: tongue (48%; n=24 and gums (22%; n=11. Among elderly women, 24 (48.0% had daily symptoms. Regarding self-reported diseases and habits: 80.0% cited cardiovascular diseases, 74.0% (n=37 musculoskeletal illness and 62.0% (n=31 neurological disorders, besides 56.0% (n=28 present reduction of salivary flow; 70.0% (n=35 took medication, 66.0% (n=33 were users of dental prosthesis and 18.0% (n=9 did not brush their teeth. Conclusions: The prevalence of burning mouth symptoms in this group was 19%; scalding sensation was the main manifestation of the symptom and the tongue was the site of major symptomatology. The epidemiological profile of symptomatic elderly was distinguished by self-reported diseases and habits such as cardiovascular, musculoskeletal and neurological disorders, in addition to reduced salivary flow, as well as the use of medications and dental prosthesis.

  19. Preface [Hyperfine Interactions, ISSN 0304-3843, Nov 2017, v. 238(1), p. 1-2

    Energy Technology Data Exchange (ETDEWEB)

    Kowalska, Magdalena, E-mail: magdalena.kowalska@cern.ch [CERN, EP Department (Switzerland); Błaszczak, Zdzislaw, E-mail: zetbe@amu.edu.pl [Adam Mickiewicz University, Faculty of Physics (Poland)

    2017-11-15

    It is with great pleasure that we are presenting the subsequent volume of the International Poznan Workshop proceedings. The conferences of this cycle have been since the beginning devoted to laser light interaction with atomic nuclei and since more recently also to the applications of ion-storage devices. The first edition entitled “Laser Spectroscopy of Atomic Nuclei” took place in Dubna in December 1990, and since then the subsequent conferences have been held every two to three years in Poznan, where they have been jointly organized by the Faculty of Physics at the Adam Mickiewicz University (Poznan) and the Flerov Laboratory of Nuclear Reactions at the Joint Institute of Nuclear Research (Dubna). The conferences have enjoyed increasing popularity and have attracted increasing numbers of specialists from a number of research institutions engaged in laser spectroscopy of radioactive and other exotic (e.g. anti-) atomic nuclei and related instruments. Over the years the workshops have gained a reputation of presenting research of a high scientific level and having impact on the directions of future studies. The 2016 workshop on the Application of Lasers and Storage Devices in Atomic Nuclei Research has been already the 10{sup th} edition and it was a pleasure to see that the event was thriving and the participants were enjoying it in all fronts. Around 100 scientists met on May 16 -19 in Poznan for the 4-day event. They were even more international than in the previous edition, representing institutes in Europe, North America, Japan, and even Australia. Many have returned to Poznan, but there were also new faces, especially among the younger participants. It was great to see the leaders in their topics discussing physics, but not only, with PhD students and starting post-docs. More than sixty talks were delivered, reflecting well the state-of-the art in the covered fields which were all related to the techniques, experimental results and theory connected to lasers and storage devices applied to exotic nuclei. The presentations were supplemented with many posters covering even more results. We hope that the participants also enjoyed the concert of renaissance music. In this warm atmosphere (much warmer than the temperatures outside the lecture hall), we are looking forward to the 11 {sup th} edition, which has been already announced to take place again in Poznan. In the next 3 years many new results will be certainly collected, so that without doubt we will participate in another interesting workshop.

  20. On the use of a molten salt fast reactor to apply an idealized transmutation scenario for the nuclear phase out.

    Science.gov (United States)

    Merk, Bruno; Rohde, Ulrich; Glivici-Cotruţă, Varvara; Litskevich, Dzianis; Scholl, Susanne

    2014-01-01

    In the view of transmutation of transuranium (TRU) elements, molten salt fast reactors (MSFRs) offer certain advantages compared to solid fuelled reactor types like sodium cooled fast reactors (SFRs). In the first part these advantages are discussed in comparison with the SFR technology, and the research challenges are analyzed. In the second part cycle studies for the MSFR are given for different configurations--a core with U-238 fertile, a fertile free core, and a core with Th-232 as fertile material. For all cases, the transmutation potential is determined and efficient transmutation performance for the case with thorium as a fertile material as well as for the fertile free case is demonstrated and the individual advantages are discussed. The time evolution of different important isotopes is analyzed. In the third part a strategy for the optimization of the transmutation efficiency is developed. The final aim is dictated by the phase out decision of the German government, which requests to put the focus on the determination of the maximal transmutation efficiency and on an as much as possible reduced leftover of transuranium elements at the end of the reactor life. This minimal leftover is achieved by a two step procedure of a first transmuter operation phase followed by a second deep burning phase. There the U-233, which is bred in the blanket of the core consisting of thorium containing salt, is used as feed. It is demonstrated, that transmutation rates up to more than 90% can be achieved for all transuranium isotopes, while the production of undesired high elements like californium is very limited. Additionally, the adaptations needed for the simulation of a MSFR, and the used tool HELIOS 1.10 is described.