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Sample records for 6th us-russian pu

  1. Dietary studies in the joint US-Russian space program

    NASA Technical Reports Server (NTRS)

    Rice, B. L.; Lane, H. W.

    1997-01-01

    Metabolic experiments in the joint US-Russian space program involve analysis of food records, which include weighed foods, stable-isotope turnover, and biochemical samples collected before, during, and after the flights. This article describes the methods of monitoring dietary intake for this program.

  2. Mars Together 2001: Joint US-Russian Team

    NASA Technical Reports Server (NTRS)

    Ulrich, P.; Kremnev, R.; Boyce, J.; Eremenko, A.; Bourke, R.; Linkin, V.; Campbell, J.; Martynov, B.; Haynes, N.; Mitrofanov, I.; Lowry, L.; Moroz, V.; Miller, S.; Papkov, O.; Pichkhadze, K.

    1996-01-01

    While the US and USSR have collaborated in human space flight and Earth application missions, this is the first time in the cultural relations between our two countries that American and Russian specialists have been authorized to work together on a joint space science mission. A study was commissioned to investigate the possibility of a combined US/Russian mission in the 2001 opportunity. A basic option for a proposed mission (abbreviated as MT 2001) was adopted. This option is described.

  3. 6th International Microbeam Workshop

    SciTech Connect

    Dr Kevin M. Prise

    2004-01-01

    The extended abstracts which are submitted here present a summary of the proceedings of the 6th International Workshop/12th LH Gray Workshop: Microbeam Probes of Cellular Radiation Response, held at St. Catherine's College, University of Oxford, UK on March, 29th-31st, 2003. In 1993 the 4th LH Gray Workshop entitled ''Microbeam Probes of Cellular Radiation Response'' was held at the Gray Cancer Institute in Northwood. This was organized by Prof BD Michael, Dr M. Folkard and Dr KM Prise and brought together 40 participants interested in developing and applying new microbeam technology to problems in radiation biology (1). The workshop was an undoubted success and has spawned a series of subsequent workshops every two years. In the past, these workshops have been highly successful in bringing together groups interested in developing and applying micro-irradiation techniques to the study of cell and tissue damage by ionizing radiations. Following the first microbeam workshop, there has been a rapid growth in the number of centres developing radiobiology microbeams, or planning to do so and there are currently 15-20 worldwide. Much of the recent research using microbeams has used them to study low-dose effects and ''non-targeted'' responses such bystander effects, genomic instability and adaptive responses. The goal of the 6th workshop was to build on our knowledge of the development of microbeam approaches and the application to radiation biology in the future with the meeting stretching over a 3 day period. Over 80 participants reviewed the current state of radiobiology microbeam research worldwide and reported on new technological developments both in the fields of physics and biology.

  4. Proceedings -- US Russian workshop on fuel cell technologies

    SciTech Connect

    Baker, B.; Sylwester, A.

    1996-04-01

    On September 26--28, 1995, Sandia National Laboratories sponsored the first Joint US/Russian Workshop on Fuel Cell Technology at the Marriott Hotel in Albuquerque, New Mexico. This workshop brought together the US and Russian fuel cell communities as represented by users, producers, R and D establishments and government agencies. Customer needs and potential markets in both countries were discussed to establish a customer focus for the workshop. Parallel technical sessions defined research needs and opportunities for collaboration to advance fuel cell technology. A desired outcome of the workshop was the formation of a Russian/American Fuel Cell Consortium to advance fuel cell technology for application in emerging markets in both countries. This consortium is envisioned to involve industry and national labs in both countries. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  5. 6th Amino Acid Assessment Workshop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The focus of the 6th workshop is on lysine, arginine, and related amino acids. Functions, metabolic pathways, clinical uses, and upper tolerance intakes are emphasized in the articles that follow. Lysine is arguably the most deficient amino acid in the food supply of countries where poverty exists, ...

  6. PREFACE: 6th Liquid Matter Conference

    NASA Astrophysics Data System (ADS)

    Dijkstra, Marjolein; van Roij, René; Vroege, Gert Jan; Lekkerkerker, Henk; Frenkel, Daan

    2005-11-01

    This special issue of Journal of Physics: Condensed Matter contains the Proceedings of the 6th Liquid Matter Conference held in Utrecht, The Netherlands, 2-6 July 2005. The three-yearly Liquid Matter Conference is organized by the Liquids Section of the Condensed Matter Division of the European Physical Society. This series of meetings began in Lyon in 1990. The most recent meeting was held in 2003 in Konstanz. The aim of the Liquid Matter Conferences is to bring together scientists working on the liquid state of matter. This rapidly growing field includes the physics, chemistry, biology and chemical engineering of liquid matter as well as various applied research areas. In fact, the Utrecht meeting had, for the first time, a special session devoted to Fundamental Challenges in Applied Liquid Physics and Microfluidics. The Utrecht meeting had 760 registered participants from four continents. An important event at this meeting was the award of the First Liquid Matter Prize of the European Physical Society to Professor Jean-Pierre Hansen FRS, of Cambridge University. In addition to a plenary speech by the recipient of the Liquid Matter Prize, the scientific programme consisted of 10 plenary lectures, 117 symposia talks, 25 of which were keynote lectures and some 650 poster contributions. The meeting also hosted a one-day symposium of the Division of Liquids and Interfaces of the Chemical Sciences division of NWO. This special issue of Journal of Physics: Condensed Matter contains 61 of the oral communications. Liquid state physics is at the interface of many fields of research. As a consequence, many of the attendants come from adjacent fields and find in the Liquid Matter Conference a forum to meet experts from other areas of research. This aspect of the Liquid Matter Conference makes it an exciting meeting as it not only offers the participants an up-to-date picture of the status of research into the liquid state of matter, but it also allows them to establish new

  7. 6th International Meshing Roundtable '97

    SciTech Connect

    White, D.

    1997-09-01

    The goal of the 6th International Meshing Roundtable is to bring together researchers and developers from industry, academia, and government labs in a stimulating, open environment for the exchange of technical information related to the meshing process. In the pas~ the Roundtable has enjoyed significant participation born each of these groups from a wide variety of countries. The Roundtable will consist of technical presentations from contributed papers and abstracts, two invited speakers, and two invited panels of experts discussing topics related to the development and use of automatic mesh generation tools. In addition, this year we will feature a "Bring Your Best Mesh" competition and poster session to encourage discussion and participation from a wide variety of mesh generation tool users. The schedule and evening social events are designed to provide numerous opportunities for informal dialog. A proceedings will be published by Sandia National Laboratories and distributed at the Roundtable. In addition, papers of exceptionally high quaIity will be submitted to a special issue of the International Journal of Computational Geometry and Applications. Papers and one page abstracts were sought that present original results on the meshing process. Potential topics include but are got limited to: Unstructured triangular and tetrahedral mesh generation Unstructured quadrilateral and hexahedral mesh generation Automated blocking and structured mesh generation Mixed element meshing Surface mesh generation Geometry decomposition and clean-up techniques Geometry modification techniques related to meshing Adaptive mesh refinement and mesh quality control Mesh visualization Special purpose meshing algorithms for particular applications Theoretical or novel ideas with practical potential Technical presentations from industrial researchers.

  8. The 6th International Earth Science Olympiad: A Student Perspective

    ERIC Educational Resources Information Center

    Barlett, Luke; Cathro, Darcy; Mellow, Maddi; Tate, Clara

    2014-01-01

    In October 2012, two students from the Australian Science and Mathematics School and two from Yankalilla Area School were selected to travel to Olavarria, Argentina in order to compete in the 6th International Earth Science Olympiad (IESO). It was an opportunity for individuals with a passion for Earth science to come together from 17 countries to…

  9. The NACVE 6th Report: An Interpretation of Its Meaning.

    ERIC Educational Resources Information Center

    Hoyt, Kenneth B.

    The author comments on the meaning of the 16 recommendations of NACVE's 6th Report (Counseling and Guidance: A Call for Change), and emphasizes their basic consistency with policies of both the APGA and the AVA. The remainder of the paper addresses the questions now facing counselors, such as why nothing more is being done to implement these…

  10. 6th Golden Helix Pharmacogenomics Day: pharmacogenomics and individualized therapy.

    PubMed

    Stojiljkovic, Maja; Fazlagic, Amira; Dokmanovic-Krivokapic, Lidija; Nikcevic, Gordana; Patrinos, George P; Pavlovic, Sonja; Zukic, Branka

    2012-09-25

    The Golden Helix Pharmacogenomics Days are international scientific meetings aiming to educate healthcare professionals and biomedical scientists about pharmacogenomics and personalized medicine. In this meeting report, we provide an overview of the scientific lectures and the topics discussed during the 6th Golden Helix Pharmacogenomics Day that was held in Belgrade, Serbia last June 5, 2012. The scientific program included lectures by the local and international speakers from Europe and the United States.

  11. Fundamentals of Physics, 6th Edition Enhanced Problems Version

    NASA Astrophysics Data System (ADS)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2002-04-01

    No other text on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics. This text continues to outperform the competition year after year, and the new edition will be no exception. Intended for Calculus-based Physics courses, the 6th edition of this extraordinary text is a major redesign of the best-selling 5th edition, which still maintains many of the elements that led to its enormous success. Jearl Walker adds his unique style to this edition with the addition of new problems designed to capture, and keep, students' attention. Nearly all changes are based on suggestions from instructors and students using the 5th edition, from reviewer comments, and from research done on the process of learning. The primary goal of this text is to provide students with a solid understanding of fundamental physics concepts, and to help them apply this conceptual understanding to quantitative problem solving. The principal goal of Halliday-Resnick-Walker is to provide instructors with a tool by which they can teach students how to effectively read scientific material and successfully reason through scientific questions. To sharpen this tool, the Enhanced Problems Version of the sixth edition of Fundamentals of Physics contains over 1000 new, high-quality problems that require thought and reasoning rather than simplistic plugging of data into formulas.

  12. PREFACE: 6th EEIGM International Conference on Advanced Materials Research

    NASA Astrophysics Data System (ADS)

    Horwat, David; Ayadi, Zoubir; Jamart, Brigitte

    2012-02-01

    The 6th EEIGM Conference on Advanced Materials Research (AMR 2011) was held at the European School of Materials Engineering (EEIGM) on the 7-8 November 2011 in Nancy, France. This biennial conference organized by the EEIGM is a wonderful opportunity for all scientists involved in the EEIGM programme, in the 'Erasmus Mundus' Advanced Materials Science and Engineering Master programme (AMASE) and the 'Erasmus Mundus' Doctoral Programme in Materials Science and Engineering (DocMASE), to present their research in the various fields of Materials Science and Engineering. This conference is also open to other universities who have strong links with the EEIGM and provides a forum for the exchange of ideas, co-operation and future orientations by means of regular presentations, posters and a round-table discussion. This edition of the conference included a round-table discussion on composite materials within the Interreg IVA project '+Composite'. Following the publication of the proceedings of AMR 2009 in Volume 5 of this journal, it is with great pleasure that we present this selection of articles to the readers of IOP Conference Series: Materials Science and Engineering. Once again it represents the interdisciplinary nature of Materials Science and Engineering, covering basic and applicative research on organic and composite materials, metallic materials and ceramics, and characterization methods. The editors are indebted to all the reviewers for reviewing the papers at very short notice. Special thanks are offered to the sponsors of the conference including EEIGM-Université de Lorraine, AMASE, DocMASE, Grand Nancy, Ville de Nancy, Region Lorraine, Fédération Jacques Villermaux, Conseil Général de Meurthe et Moselle, Casden and '+Composite'. Zoubir Ayadi, David Horwat and Brigitte Jamart

  13. The role and modulation of CCR6+ Th17 cell populations in rheumatoid arthritis.

    PubMed

    Paulissen, Sandra M J; van Hamburg, Jan Piet; Dankers, Wendy; Lubberts, Erik

    2015-07-01

    The IL-17A producing T-helper-17 (Th17) cell population plays a major role in rheumatoid arthritis (RA) pathogenesis and has gained wide interest as treatment target. IL-17A expressing Th cells are characterized by the expression of the chemokine receptor CCR6 and the transcription factor RORC. In RA, CCR6+ Th cells were identified in peripheral blood, synovial fluid and inflamed synovial tissue. CCR6+ Th cells might drive the progression of an early inflammation towards a persistent arthritis. The CCR6+ Th cell population is heterogeneous and several subpopulations can be distinguished, including Th17, Th22, Th17.1 (also called non-classic Th1 cells), and unclassified or intermediate populations. Interestingly, some of these populations produce low levels of IL-17A but are still very pathogenic. Furthermore, the CCR6+ Th cells phenotype is unstable and plasticity exists between CCR6+ Th cells and T-regulatory (Treg) cells and within the CCR6+ Th cell subpopulations. In this review, characteristics of the different CCR6+ Th cell populations, their plasticity, and their potential impact on rheumatoid arthritis are discussed. Moreover, current approaches to target CCR6+ Th cells and future directions of research to find specific CCR6+ Th cell targets in the treatment of patients with RA and other CCR6+ Th cell mediated autoimmune diseases are highlighted.

  14. Proceedings of the 6th European VLBI Network Symposium

    NASA Astrophysics Data System (ADS)

    Ros, Eduardo; Porcas, Richard W.; Lobanov, Andrei P.; Zensus, J. Anton

    This volume contains the papers presented at the 6th Symposium of the European VLBI Network, held in Bonn on 25-28 June 2002. The initial aim of these biennial gatherings of European VLBI practitioners was to review in a timely manner new results and technical developments related to Very Long Baseline Interferometry. Now, however, interest and participation in the EVN Symposia reaches far beyond Europe, reflecting the fact that scientific research and development programs are carried out to a high degree in international and often truly global collaborations. More than 120 scientists from around the world registered for participation in the Symposium. The Symposium was hosted by the Max-Planck-Institut für Radioastronomie and was held at the Gustav Stresemann Institut. In addition to the scientific sessions and poster presentations, the program included an EVN Users Meeting, an MPIfR versus Rest-of-the-World football match (highly appropriate given the competing World Cup event!), a visit to the MPIfR's 100m radio telescope in Effelsberg, and a Conference Dinner held in the nearby old walled town of Bad Müunstereifel. To maximize the usefulness of these proceedings (and possibly as a daring precedent) the Editors decided to demand the written versions of talks and posters and to complete the editorial work before the meeting, and to deliver the book to the participants at the beginning of the Symposium. We thank the authors for their cooperation in delivering publication-ready electronic manuscripts and for meeting the strict deadlines. It is highly gratifying that only a handful of the 100 presentations are not represented in this volume. The editors have made minor changes to some of the contributions in order to improve readability, and take responsibility for any errors arising from these changes. Besides the authors, many individuals have contributed to the preparation of the meeting and its proceedings. In addition to many members of the MPIfR staff, we

  15. PREFACE: The 6th Nordic Meeting on Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Løvhøiden, G.; Thorsteinsen, T. F.; Vaagen, J. S.

    1990-01-01

    After an unintended time gap of five years, the series of regular Nordic meetings on nuclear physics was continued with the 6th Nordic Meeting, August 10-15, 1989. The site was Utgarden in the outskirts of Kopervik, the administration center for the Saga island of Karmøy on the west-coast of Norway. Utgarden, a "peoples high-school'' with a kitchen, housing facility and a neighboring modern gymnasium with fine lecture halls, proved to be an inexpensive and adequate site for the meeting. From the time of the Vikings, the sound between Karmøyy and the mainland has been a vital part of the way to the north. Mobility and international orientation is still a signature of an area where today essential parts of Norway's oil- and metal industry are located. The conference program included a session on nuclear physics in industry and society, with contributed talks from a number of companies and technology/research institutions, which also sponsored the meeting. Lunch visits to Hydro's aluminium plant on Karmøy or alternatively to Statoil's gas terminal on the mainland, were included in the program. The scientific program gives a cross section of nuclear physics activities in which researchers from the Nordic countries are involved nowadays. The spectrum is rich, and the emphasis has shifted to higher energies than was the case five years ago. We appreciate the possibility to present this overview in a separate volume of Physica Scripta. The present issue covers nearly all the talks given at the meeting. The order deviates, however, somewhat from that of the conference program. The organizing committee tried to encourage in various ways the participation of young physicists; this effort was truely rewarded. The young participants put their imprint on the activities in the lecture halls and even more on the soccer arena. The meeting was sponsored by The University of Bergen, The Nordic Accelerator Committee, NORDITA, The Norwegian Research Council for Science and the

  16. US/Russian laboratory-to-laboratory MPC&A Program at the VNIITF Institute, Chelyabinsk-70 May 1996

    SciTech Connect

    Tsygankov, G.; Churikov, Y.; Teryokhin, V.

    1996-05-01

    The AR Russian Institute of Technical Physics (VNIITF), also called Chelyabinsk-70, is one of two Russian federal nuclear centers established to design, test and support nuclear weapons throughout their life cycle. The site contains research facilities which use nuclear materials, two experimental plants which manufacture prototype samples for nuclear weapons, and a site for various ground tests. Chelyabinsk-70 also has cooperative relationships with the major nuclear materials production facilities in the Urals region of Russia. Chelyabinsk-70 has been participating in the US/Russian Laboratory-to-laboratory cooperative program for approximately one year. Six US Department of Energy Laboratories are carrying out a program of cooperation with VNIITF to improve the capabilities and facilities for nuclear materials protection, control, and accounting (MPC&A) at VNIITF. A Safeguards Effectiveness Evaluation Workshop was conducted at VNIITF in July, 1995. Enhanced safeguards systems are being implemented, initially at a reactor test area that contains three pulse reactors. Significant improvements to physical security and access control systems are under way. C-70 is developing an extensive computerized system that integrates the physical security alarm station with elements of the nuclear material control system. The existing systems will be augmented with Russian and US technologies. This paper will describe the on-going activities and describe the cooperative effort between the Lawrence Livermore, Los Alamos, Sandia, Oak Ridge, Pacific Northwest, and Brookhaven US Department of Energy National Laboratories and VNIITF.

  17. 169. GENERAL VIEW DOWN 6TH AVE. VIEW TO SOUTHWEST DOWN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    169. GENERAL VIEW DOWN 6TH AVE. VIEW TO SOUTHWEST DOWN 6TH AVE. SHOWING FROM LEFT TO RIGHT, BUILDING 8 (HOSPITAL) WITH PART OF ONE OF ITS 1-STORY WARD WINGS, AND THE 3 ORIGINAL DORMITORY WINGS OF BUILDING 9 (BOQ). - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  18. 3. BUILDING 522, EAST SIDE, FROM ACROSS 6TH STREET AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. BUILDING 522, EAST SIDE, FROM ACROSS 6TH STREET AT ITS INTERSECTION WITH G STREET, LOOKING NORTHWEST. - Oakland Naval Supply Center, Aeronautical Materials Storehouses, Between E & G Streets, between Fourth & Sixth Streets, Oakland, Alameda County, CA

  19. Conference summary: 6th International conference on hyperons, charm, and beauty hadrons (BEACH04)

    SciTech Connect

    Butler, Joel N.; /Fermilab

    2004-12-01

    The 6th International Conference on Hyperons, Charm, and Beauty Hadrons (BEACH04) treated us to a wonderful array of new results. Here the author attempts to summarize the talks and discuss the conference highlights.

  20. 11. Interior view, working house, elevator head floor (6th of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Interior view, working house, elevator head floor (6th of top level); view facing east, toward head of no. 2 leg and ropedrive sheave. - Saint Anthony Elevator No. 3, 620 Malcom Avenue, Southeast, Minneapolis, Hennepin County, MN

  1. Purification of 238Pu Oxide using the Pu Oxalate Process

    SciTech Connect

    Mew, D A; Krikorian, O H; Dodson, K E; Schmitz, J A

    2001-11-28

    The Pu oxalate process is used to remove {sup 234}U from aged {sup 238}Pu-enriched PuO{sub 2} ({sup 234}U grows into the PuO{sub 2} material with time from a-decay of {sup 238}Pu). The Pu oxalate process was first used on a mixture of weapons grade PuO{sub 2} with UO{sub 2} to work out the processing parameters. It was then applied to aged {sup 238}Pu-enriched PuO{sub 2} ({sup 238}PuO{sub 2}). The {sup 234}U content of the {sup 238}PuO{sub 2} was reduced from 13.2 wt% to 0.0254 wt%, and the Pu recovery yield was 78.5%. The process is complex and is complicated by radiolysis problems when working with {sup 238}Pu. Details of the experiments are described.

  2. Curriculum Reform Movements and Science Textbooks: A Retrospective Examination of 6th Grade Science Textbooks

    ERIC Educational Resources Information Center

    Alpaslan, Muhammet Mustafa; Yalvac, Bugrahan; Loving, Cathleen C.

    2015-01-01

    Over 50 years, two major reform efforts in science education took place. The purpose of the present study is to explore how the educational reforms were reflected in nine 6th grade science textbooks published in 1975, in 1985 and in 1997 in terms of (a) the materials used, (b) the contexts to which the electricity concept was related, (c) the type…

  3. Oral Persuasion: A Saleable Work Skill. Occupation Simulation Packet. Grades 5th-6th.

    ERIC Educational Resources Information Center

    Lee, Dennis W.

    This teacher's guide contains simulated work experiences for 5th and 6th grade students using the isolated skill concept - oral persuasion. Teacher instructions include objectives, evaluation, and sequence of activities. The guide contains pre-tests and post-tests with instructions and answer keys. Two pre-skill activities are suggested, such as…

  4. Summary of the National Technicians' Conference ASE/NSLC York--5/6th July 2012

    ERIC Educational Resources Information Center

    Bostock, Julia, Comp.

    2012-01-01

    This article presents a summary of the National Technicians' Conference ASE/NSLC York from July 5th to July 6th 2012. Approximately 160 technicians attended the Conference on both days. The programme included workshops and lectures and was repeated on the Friday, so that technicians who stayed for both days were able to take part in a variety of…

  5. Proceedings of the 6th national conference on hazardous wastes and hazardous materials

    SciTech Connect

    Not Available

    1989-01-01

    This book contained the proceedings of the 6th national Conference on Hazardous wastes and Hazardous materials. Topics covered include: federal and state policy papers, risk assessment, health and endangerment, contaminated groundwater control, treatment, spill control management and tank leakage control.

  6. Sneak Preview of Berkeley Lab's Science at the Theatre on June 6th, 2011

    SciTech Connect

    Sanii, Babak

    2011-01-01

    Babak Sanii provides a sneak preview of Berkeley Lab's next Science at the Theater Event: Big Thinking: The Power of Nanoscience. Berkeley Lab scientists reveal how nanoscience will bring us cleaner energy, faster computers, and improved medicine. Berkeley Repertory Theatre on June 6th, 2011

  7. Sneak Preview of Berkeley Lab's Science at the Theatre on June 6th, 2011

    ScienceCinema

    Sanii, Babak

    2016-07-12

    Babak Sanii provides a sneak preview of Berkeley Lab's next Science at the Theater Event: Big Thinking: The Power of Nanoscience. Berkeley Lab scientists reveal how nanoscience will bring us cleaner energy, faster computers, and improved medicine. Berkeley Repertory Theatre on June 6th, 2011

  8. 10. 'Southern Pacific Company, 6th Crossing of Sacramento River, One ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. 'Southern Pacific Company, 6th Crossing of Sacramento River, One 208'-10-1/2' C. to C. End Pins S. Tr. Thro. Skew Span, Scale 1' = 10', The Phoenix Bridge Co., Phoenixville, Pa., April 12, 1901, Drg. 45' - Southern Pacific Railroad Shasta Route, Bridge No. 301.85, Milepost 301.85, Pollard Flat, Shasta County, CA

  9. Anaerobic Biotransformation and Mobility of Pu and Pu-EDTA

    SciTech Connect

    Bolton, H., Jr.; Bailey, V.L.; Plymale, A.E.; Rai, D.; Xun, L.

    2006-04-05

    The complexation of radionuclides (e.g., plutonium (Pu) and {sup 60}Co) by co-disposed ethylenediaminetetraacetate (EDTA) has enhanced their transport in sediments at DOE sites. Pu(IV)-EDTA is not stable in the presence of relatively soluble Fe(III) compounds. Since most DOE sites have Fe(III) containing sediments, Pu(IV) is likely not the mobile form of Pu-EDTA. The only other Pu-EDTA complex stable in groundwater relevant to DOE sites would be Pu(III)-EDTA, which only forms under anaerobic conditions. Research is therefore needed to investigate the biotransformation of Pu and Pu-EDTA under anaerobic conditions and the anaerobic biodegradation of Pu-EDTA. The biotransformation of Pu and Pu-EDTA under various anaerobic regimes is poorly understood including the reduction kinetics of Pu(IV) to Pu(III) from soluble (Pu(IV)-EDTA) and insoluble Pu(IV), the redox conditions required for this reduction, the strength of the Pu(III)-EDTA, how the Pu(III)-EDTA competes with other dominant anoxic soluble metals (e.g., Fe(II)), and the oxidation kinetics of Pu(III)-EDTA. Finally, soluble Pu(III)-EDTA under anaerobic conditions would require anaerobic degradation of the EDTA to limit Pu(III) transport. Anaerobic EDTA degrading microorganisms have never been isolated. Recent results have shown that Shewanella oneidensis MR-1, a dissimilatory metal reducing bacterium, can reduce Pu(IV) to Pu(III). The Pu(IV) was provided as insoluble PuO2. The highest rate of Pu(IV) reduction was with the addition of AQDS, an electron shuttle. Of the total amount of Pu solubilized (i.e., soluble through a 0.36 nm filter), approximately 70% was Pu(III). The amount of soluble Pu was between 4.8 and 3.2 micromolar at day 1 and 6, respectively, indicating rapid reduction. The micromolar Pu is significant since the drinking water limit for Pu is 10{sup -12} M. On-going experiments are investigating the influence of EDTA on the rate of Pu reduction and the stability of the formed Pu(III). We have also

  10. Prevalence of Elevated Blood Pressure in Hispanic versus Non-Hispanic 6th Graders

    ERIC Educational Resources Information Center

    Tarlton, Patricia A.

    2007-01-01

    Blood pressure screening was conducted on 4,311 (Hispanic n = 763 [17.7%], White n = 2,566 [59.5%], African American n = 610 [14.1%], Asian n = 136 [3.2%], Multiracial n = 231 [5.4%], and Native American n = 5 [0.1%]) 6th-grade students enrolled in Seminole County, Florida, Public Schools from August to December 2005. Prevalence of obesity was 21%…

  11. Anaerobic Biotransformation and Mobility of Pu and Pu-EDTA

    SciTech Connect

    Bolton, H., Jr.; Rai, D.; Xun, L.

    2005-04-18

    The complexation of radionuclides (e.g., plutonium (Pu) and {sup 60}Co) by codisposed ethylenediaminetetraacetate (EDTA) has enhanced their transport in sediments at DOE sites. Our previous NABIR research investigated the aerobic biodegradation and biogeochemistry of Pu(IV)-EDTA. Plutonium(IV) forms stable complexes with EDTA under aerobic conditions and an aerobic EDTA degrading bacterium can degrade EDTA in the presence of Pu and decrease Pu mobility. However, our recent studies indicate that while Pu(IV)-EDTA is stable in simple aqueous systems, it is not stable in the presence of relatively soluble Fe(III) compounds (i.e., Fe(OH){sub 3}(s)--2-line ferrihydrite). Since most DOE sites have Fe(III) containing sediments, Pu(IV) in likely not the mobile form of Pu-EDTA in groundwater. The only other Pu-EDTA complex stable in groundwater relevant to DOE sites would be Pu(III)-EDTA, which only forms under anaerobic conditions. Research is therefore needed in this brand new project to investigate the biotransformation of Pu and Pu-EDTA under anaerobic conditions. The biotransformation of Pu and Pu-EDTA under various anaerobic regimes is poorly understood including the reduction kinetics of Pu(IV) to Pu(III) from soluble (Pu(IV)-EDTA) and insoluble Pu(IV) as PuO2(am) by metal reducing bacteria, the redox conditions required for this reduction, the strength of the Pu(III)-EDTA complex, how the Pu(III)-EDTA complex competes with other dominant anoxic soluble metals (e.g., Fe(II)), and the oxidation kinetics of Pu(III)-EDTA. Finally, the formation of a stable soluble Pu(III)-EDTA complex under anaerobic conditions would require degradation of the EDTA complex to limit Pu(III) transport in geologic environments. Anaerobic EDTA degrading microorganisms have not been isolated. These knowledge gaps preclude the development of a mechanistic understanding of how anaerobic conditions will influence Pu and Pu-EDTA fate and transport to assess, model, and design approaches to stop

  12. Pu(V) and Pu(IV) sorption to montmorillonite.

    PubMed

    Begg, James D; Zavarin, Mavrik; Zhao, Pihong; Tumey, Scott J; Powell, Brian; Kersting, Annie B

    2013-05-21

    Plutonium (Pu) adsorption to and desorption from mineral phases plays a key role in controlling the environmental mobility of Pu. Here we assess whether the adsorption behavior of Pu at concentrations used in typical laboratory studies (≥10(-10) [Pu] ≤ 10(-6) M) are representative of adsorption behavior at concentrations measured in natural subsurface waters (generally <10(-12) M). Pu(V) sorption to Na-montmorillonite was examined over a wide range of initial Pu concentrations (10(-6)-10(-16) M). Pu(V) adsorption after 30 days was linear over the wide range of concentrations studied, indicating that Pu sorption behavior from laboratory studies at higher concentrations can be extrapolated to sorption behavior at low, environmentally relevant concentrations. Pu(IV) sorption to montmorillonite was studied at initial concentrations of 10(-6)-10(-11) M and was much faster than Pu(V) sorption over the 30 day equilibration period. However, after one year of equilibration, the extent of Pu(V) adsorption was similar to that observed for Pu(IV) after 30 days. The continued uptake of Pu(V) is attributed to a slow, surface-mediated reduction of Pu(V) to Pu(IV). Comparison between rates of adsorption of Pu(V) to montmorillonite and a range of other minerals (hematite, goethite, magnetite, groutite, corundum, diaspore, and quartz) found that minerals containing significant Fe and Mn (hematite, goethite, magnetite, and groutite) adsorbed Pu(V) faster than those which did not, highlighting the potential importance of minerals with redox couples in increasing the rate of Pu(V) removal from solution. PMID:23614502

  13. Biotransformation of PuEDTA: Implications to Pu Immobilization

    SciTech Connect

    Bolton, Harvey, Jr.

    2006-06-01

    This project integrates three distinct goals to develop a fundamental understanding of the potential fate and disposition of plutonium in sediments that are co-contaminated with EDTA. The three objectives are: (1) Develop thermodynamic data for Pu-EDTA species and determine the dominant mobile form of Pu under anaerobic conditions. (2) Elucidate the mechanism and rates of Pu(IV) and Pu(IV)-EDTA reduction by metal-reducing bacteria and determine where the Pu is located (in solution, biosorbed, bioaccumulated). (3) Enrich and isolate anaerobic EDTA-degrading microorganisms to investigate the anaerobic biodegradation of Pu-EDTA.

  14. Pu-239 and Pu-240 inventories and Pu-240/ Pu-239 atom ratios in the water column off Sanriku, Japan.

    NASA Astrophysics Data System (ADS)

    Yamada, Masatoshi; Zheng, Jian; Aono, Tatsuo

    2013-04-01

    A magnitude 9.0 earthquake and subsequent tsunami occurred in the Pacific Ocean off northern Honshu, Japan, on 11 March 2011 which caused severe damage to the Fukushima Dai-ichi Nuclear Power Plant. This accident has resulted in a substantial release of radioactive materials to the atmosphere and ocean, and has caused extensive contamination of the environment. However, no information is available on the amounts of radionuclides such as Pu isotopes released into the ocean at this time. Investigating the background baseline concentration and atom ratio of Pu isotopes in seawater is important for assessment of the possible contamination in the marine environment. Pu-239 (half-life: 24,100 years), Pu-240 (half-life: 6,560 years) and Pu-241 (half-life: 14.325 years) mainly have been released into the environment as the result of atmospheric nuclear weapons testing. The atom ratio of Pu-240/Pu-239 is a powerful fingerprint to identify the sources of Pu in the ocean. The Pu-239 and Pu-240 inventories and Pu-240/Pu-239 atom ratios in seawater samples collected in the western North Pacific off Sanriku before the accident at Fukushima Dai-ichi Nuclear Power Plant will provide useful background baseline data for understanding the process controlling Pu transport and for distinguishing additional Pu sources. Seawater samples were collected with acoustically triggered quadruple PVC sampling bottles during the KH-98-3 cruise of the R/V Hakuho-Maru. The Pu-240/Pu-239 atom ratios were measured with a double-focusing SF-ICP-MS, which was equipped with a guard electrode to eliminate secondary discharge in the plasma and to enhance overall sensitivity. The Pu-239 and Pu-240 concentrations were 2.07 and 1.67 mBq/m3 in the surface water, respectively, and increased with depth; a subsurface maximum was identified at 750 m depth, and the concentrations decreased with depth, then increased at the bottom layer. The total Pu-239+240 inventory in the entire water column (depth interval 0

  15. Improving 6th Grade Climate Literacy using New Media (CLINM) and Teacher Professional Development

    NASA Astrophysics Data System (ADS)

    Smith, G.; Schmidt, C.; Metzger, E. P.; Cordero, E. C.

    2012-12-01

    The NASA-funded project, Improving 6th Grade Climate Literacy using New Media (CLINM), is designed to improve the climate literacy of California's 450,000 6th-grade students through teacher professional development that presents climate change as an engaging context for teaching earth science standards. The project fosters experience-based interaction among learners and encourages expressive creativity and idea-exchange via the web and social media. The heart of the CLINM project is the development of an online educator-friendly experience that provides content expert-reviewed, teacher-tested, standards-based educational resources, classroom activities and lessons that make meaningful connections to NASA data and images as well as new media tools (videos, web, and phone applications) based on the Green Ninja, a climate-action superhero who fights global warming by inspiring personal action (www.greenninja.info). In this session, we will discuss this approach to professional development and share a collection of teacher-tested CLINM resources. CLINM resources are grounded in earth system science; classroom activities and lessons engage students in exploration of connections between natural systems and human systems with a particular focus on how climate change relates to everyone's need for food, water, and energy. CLINM uses a team-based approach to resource development, and partners faculty in San José State University's (SJSU) colleges of Science, Education, and Humanities and the Arts with 6th-grade teachers from local school districts, a scientist from NASA Ames Research Center and climate change education projects at Stanford University, the University of Nebraska at Lincoln, and the University of Idaho. Climate scientists and other content experts identify relevant concepts and work with science educators to develop and/or refine classroom activities to elucidate those concepts; activities are piloted in pre-service science methods courses at SJSU and in

  16. Bone Lose of the Ancient Mediterranean lumbar vertebrae : Iasos, 6th century ad.

    NASA Astrophysics Data System (ADS)

    Kaya, Serdar; Solmaz, Ilker; Ilıca, A. Turan; Karaçalıoğlu, Özgür; Damla Yılmaz, Nalan; Başoğlu, Okşan; Kılıc, Selim; Izci, Yusuf

    Evaluation of bone mineral density (BMD) of the ancient peoples has received great interest by anthropologists. The aims of this study are to investigate the lumbar vertebrae of the Iasos people during the Byzantine period, in order to determine the prevalence of bone loss and to interpret dietary conditions of ancient Mediterranean populations. Lumbar vertebrae belonging to twenty eight skeletons of the 6th c AD were analyzed by radiographs and dual energy X-ray absorptiometry. The BMD values for each biologic sex and age group were compared. The correlation between the BMD and radiological features was also analyzed. The mean BMD was 0.940 g/cm2. BMD was decreased by aging in both sexes, but it was not significant. Osteopenia was found in 11 (39%) and osteoporosis in 4 (14.3%) out 28 vertebrae. The BMD was normal in 13 (46%) out of 28 vertebrae. Osteopenia was present in 7 (38%) of 18 male vertebrae and 4 (40%) of 10 female vertebrae. The spine score was high in the male group and there was a strong positive correlation between the BMD and spine score for both sexes. This study revealed that the BMD decreased by aging and that osteopenia was a problem in both sexes of the Iasos people during the 6th c AD. There was no correlation between the BMD and radiological features for age groups and biological sexes.

  17. An integrated exploration model for Council Run field analogs: Regional geology and seismic stratigraphy of Devonian 6th Elk sandstones

    SciTech Connect

    Kelleher, G.; Johnson, R. )

    1991-08-01

    A geologic study of the Devonian Lock Haven 6th Elk formation along the structural front of Pennsylvania and Maryland suggest that present-day structures were active at the time of deposition. These structures barred deposition to the west and helped to localize sands in a northeast-southwest fairway. The 6th Elk sandstones occur in two major depositional lobes (located in Centre and Somerset counties in Pennsylvania, and Garret County, Maryland) and were deposited on a shallow-marine shelf by turbidity currents and later modified by storm-generated currents. Deposition of 6th Elk sands may also have been influenced by cross-strike discontinuities. A seismic study of the Council Run field aids in subsurface identification of the 6th Elk. A high-amplitude seismic anomaly across the Council Run field is correlated with increasing san thickness. Two dimensional modeling suggests that the seismic response is extremely sensitive to specific acquisition and processing techniques including filter and phase variability. Additional attribute analysis integrates the seismic data with the forward models. This results in a predictive method for potentially identifying 6th Elk sandstone development from seismic data. Applying the results of the seismic modeling at Council Run field to a seismic grid across the previously defined 6th Elk depositional fairway has identified many exploratory prospects in Lycoming and Bradford counties, Pennsylvania. This area coincides with the site of a third, previously documented, Upper Devonian depositional lobe.

  18. Epidemic waves during Justinian's plague in the Byzantine Empire (6th-8th c. AD).

    PubMed

    Tsiamis, C; Poulakou-Rebelakou, E; Tsakris, A; Petridou, E

    2011-06-01

    The aim of the present study is to collect the epidemic outbreaks and the epidemic waves of the bubonic plague of the Byzantine Empire during the first pandemic (541-751 AD). Human activities, such as trade and military movements have been speculated as underlying factors for the causation of the pandemic. Historical data combined with geographical spreading of the plague, allows an alternative speculation of suspicious enzootic areas in the Middle East. We conclude that the possible existence of enzootic areas in that region might have been responsible for the causation of the numerous outbreaks of the bubonic plague in the Eastern provinces of the Byzantine Empire during the 6th-8th century period.

  19. Rapid landscape change in 6th century northern Jordan: interdisciplinary geoarchaeological perspectives

    NASA Astrophysics Data System (ADS)

    Lucke, Bernhard

    2016-04-01

    Landscapes of the ancient fertile crescent are considered affected by soil degradation as result of long-term farming since the Neolithic, and impressive ruins of antiquity led to assumptions that their abandonment must have been conntected with reduced agricultural productivity. In this context, a valley fill near the site of Abila of the Decapolis in northern Jordan was apparently deposited largely during the 6th century AD, and provides evidence for a rapid and intense landscape change during the Late Byzantine period. However, an interdisciplinary case study of land use, soil development, and sediments found that the valley fill cannot be connected with large-scale soil erosion in the vicinity of the site. On the one hand, this is indicated by the distribution of soil development and archaeological material as marker of past land use activity in the past, which suggests that the best soils were and still are used intensively. On the other hand, the sediments seem to point to the occurrence of climatic extremes such as heavy floods, the occurrence of soil creep after water saturation, but also a significant shift to aridity which may have triggered socio-economic changes of subsistence strategies from agriculture to pastoralism. The dates of sediments which are available so far indicate that the climatic change seemingly occurred rapidly within approximately 100 years during the late 6th and early 7th century AD, possibly connected with the "year without sun" or 'Mystery Veil' which the Byzantine historian Procopius described in the year 536 AD. Modern analogies of the Pinatubo eruption in 1991 let it seem possible that a volcanic event, perhaps the outbreak of the Ilopango volcano, was connected with these environmental turbulences. Such events cannot be understood by isolated studies: without a broad interdisciplinary framework, single archives are prone to misinterpretation, and our understanding of the environmental history of Abila is still very limited.

  20. FOREWORD: 6th International Conference on Pumps and Fans with Compressors and Wind Turbines (ICPF2013)

    NASA Astrophysics Data System (ADS)

    Wu, Yulin; Wang, Zhengwei; Yuan, Shouqi; Shi, Weidong; Liu, Shuhong; Luo, Xingqi; Wang, Fujun

    2013-12-01

    The 6th International Conference on Pumps and Fans with Compressors and Wind Turbines (ICPF 2013) was held in Beijing, China, 19-22 September 2013, which was jointly organized by Tsinghua University and Jiangsu University. The co-organizers were Zhejiang University, Zhejiang Sci-Tech University, The State Key Laboratory of Hydroscience and Engineering, The State Key Laboratory of Automotive Safety and Energy and Beijing International Science and Technology Cooperation Base for CO2 Utilization and Reduction. The sponsor of the conference was Concepts NREC. The First International Conference on Pumps and Systems (May 1992), the Second International Conference on Pumps and Fans (October 1995), the Third International Conference on Pumps and Fans (October 1998), and the Fourth International Conference on Pumps and Fans (26-29 August 2002) were all held in Beijing and were organized by the late famous Chinese professor on fluid machinery and engineering, Professor Zuyan Mei of Tsinghua University. The conference was interrupted by the death of Professor Mei in 2003. In order to commemorate Professor Mei, the organizing committee of ICPF decided to continue organizing the conference series. The Fifth Conference on Pumps and Systems (2010 ICPF) took place in Hangzhou, Zhejiang Province, China, 18-21 October 2010, and it was jointly organized by Zhejiang University and Tsinghua University. With the development of renewable energy and new energy in China and in the world, some small types of compressor and some types of pump, as well as wind turbines are developing very fast; therefore the ICPF2013 conference included compressors and wind turbines. The theme of the conference was the application of renewable energy of pumps, compressors, fans and blowers. The content of the conference was the basic study, design and experimental study of compressors, fans, blowers and pumps; the CFD application on pumps and fans, their transient behavior, unsteady flows and multi-phase flow

  1. PREFACE: The 6th International Symposium on Measurement Techniques for Multiphase Flows

    NASA Astrophysics Data System (ADS)

    Okamoto, Koji; Murai, Yuichi

    2009-02-01

    Research on multi-phase flows is very important for industrial applications, including power stations, vehicles, engines, food processing, and so on. Also, from the environmental viewpoint, multi-phase flows need to be investigated to overcome global warming. Multi-phase flows originally have non-linear features because they are multi-phased. The interaction between the phases plays a very interesting role in the flows. The non-linear interaction causes the multi-phase flows to be very difficult to understand phenomena. The International Symposium on Measurement Techniques for Multi-phase Flows (ISMTMF) is a unique symposium. The target of the symposium is to exchange the state-of-the-art knowledge on the measurement techniques for non-linear multi-phase flows. Measurement technique is the key technology to understanding non-linear phenomena. The ISMTMF began in 1995 in Nanjing, China. The symposium has continuously been held every two or three years. The ISMTMF-2008 was held in Okinawa, Japan as the 6th symposium of ISMTMF on 15-17 December 2008. Okinawa has a long history as the Ryukyus Kingdom. China and Japan have had cultural and economic exchanges through Okinawa for more than 1000 years. Please enjoy Okinawa and experience its history to enhance our international communication. The present symposium was attended by 124 participants, the program included 107 contributions with 5 plenary lectures, 2 keynote lectures, and 100 oral regular paper presentations. The topics include, besides the ordinary measurement techniques for multiphase flows, acoustic and electric sensors, bubbles and microbubbles, computed tomography, gas-liquid interface, laser-imaging and PIV, oil/coal/drop and spray, solid and powder, spectral and multi-physics. This volume includes the presented papers at ISMTMF-2008. In addition to this volume, ten selected papers will be published in a special issue of Measurement Science and Technology. We would like to express special thanks to all

  2. PREFACE: 6th International Workshop on Multi-Rate Processes and Hysteresis (MURPHYS2012)

    NASA Astrophysics Data System (ADS)

    Dimian, Mihai; Rachinskii, Dmitrii

    2015-02-01

    The International Workshop on Multi-Rate Processes and Hysteresis (MURPHYS) conference series focuses on multiple scale systems, singular perturbation problems, phase transitions and hysteresis phenomena occurring in physical, biological, chemical, economical, engineering and information systems. The 6th edition was hosted by Stefan cel Mare University in the city of Suceava located in the beautiful multicultural land of Bukovina, Romania, from May 21 to 24, 2012. This continued the series of biennial multidisciplinary conferences organized in Cork, Ireland from 2002 to 2008 and in Pécs, Hungary in 2010. The MURPHYS 2012 Workshop brought together more than 50 researchers in hysteresis and multi-scale phenomena from the United State of America, the United Kingdom, France, Germany, Italy, Ireland, Czech Republic, Hungary, Greece, Ukraine, and Romania. Participants shared and discussed new developments of analytical techniques and numerical methods along with a variety of their applications in various areas, including material sciences, electrical and electronics engineering, mechanical engineering and civil structures, biological and eco-systems, economics and finance. The Workshop was sponsored by the European Social Fund through Sectoral Operational Program Human Resources 2007-2013 (PRO-DOCT) and Stefan cel Mare University, Suceava. The Organizing Committee was co-chaired by Mihai Dimian from Stefan cel Mare University, Suceava (Romania), Amalia Ivanyi from the University of Pecs (Hungary), and Dmitrii Rachinskii from the University College Cork (Ireland). All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing. The Guest Editors wish to place on record their sincere gratitude to Miss Sarah Toms for the assistance she provided

  3. 1/6TH SCALE STRIP EFFLUENT FEED TANK-MIXING RESULTS USING MCU SOLVENT

    SciTech Connect

    Hansen, E

    2006-02-01

    The purpose of this task was to determine if mixing was an issue for the entrainment and dispersion of the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) solvent in the Defense Waste Processing Facility (DWPF) Strip Effluent Feed Tank (SEFT). The MCU strip effluent stream containing the Cs removed during salt processing will be transferred to the DWPF for immobilization in HLW glass. In lab-scale DWPF chemical process cell testing, mixing of the solvent in the dilute nitric acid solution proved problematic, and the Savannah River National Laboratory (SRNL) was requested to perform scaled SEFT mixing tests to evaluate whether the problem was symptomatic of the lab-scale set-up or of the solvent. The solvent levels tested were 228 and 235 ppm, which represented levels near the estimated DWPF solvent limit of 239 ppm in 0.001M HNO{sub 3} solution. The 239 ppm limit was calculated by Norato in X-CLC-S-00141. The general approach for the mixing investigation was to: (1) Investigate the use of fluorescent dyes to aid in observing the mixing behavior. Evaluate and compare the physical properties of the fluorescent dyed MCU solvents to the baseline Oak Ridge CSSX solvent. Based on the data, use the dyed MCU solvent that best approximates the physical properties. (2) Use approximately a 1/6th linear scale of the SEFT to replicate the internal configuration for DWPF mixing. (3) Determine agitator speed(s) for scaled testing based on the DWPF SEFT mixing speed. (4) Perform mixing tests using the 1/6th SEFT and determine any mixing issues (entrainment/dispersion, accumulation, adhesion) through visual observations and by pulling samples to assess uniformity. The mixing tests used MCU solvent fabricated at SRNL blended with Risk Reactor DFSB-K43 fluorescent dye. This dyed SRNL MCU solvent had equivalent physical properties important to mixing as compared to the Oak Ridge baseline solvent, blended easily with the MCU solvent, and provided an excellent visual aid.

  4. Latina girls' identities-in-practice in 6th grade science

    NASA Astrophysics Data System (ADS)

    Tan, Edna

    Inequalities and achievement gaps in science education among students from different racial and socioeconomic backgrounds as well as between genders in the United States are due to not just access to resources, but also to the incongruence between identities of school science with identities salient to minority students. Minority girls are especially portrayed to be estranged from prototypical school science Discourse, often characterized as white, middle class, and masculine. This dissertation, based on a two-year ethnographic study in an urban middle school in New York City, describes the authoring of novel identities-in-practice of minority girls in a 6th grade science classroom. The findings indicate that minority girls draw from out-of-school identities salient to them to author novel identities-in-practice in the various figured worlds of the 6th grade science classroom. Through taking such authorial stances, minority girls exhibit agency in negotiating for wider boundaries in their school science participation and broker for hybrid spaces of school science where the school science Discourse was destabilized and challenged to be more inclusive of everyday funds of knowledge and Discourses important to the students. The findings also highlight the dialectic relationship between an individual students' learning and participation and the school science community-of-practice and the implications such a relationship has on the learning of both individual students and the collective community-of-practice. From year one findings, curricular adaptations were enacted, with teacher and student input, on lessons centering on food and nutrition. The adapted curriculum specifically solicited for nontraditional funds of knowledge and Discourse from students and were grounded strongly in relevance to students' out of school lives. The hybrid spaces collectively brokered for by the community-of-practice were transformed in three ways: physically, politically, and

  5. Formation of Pu amorphous alloys or metastable structures in Pu-Fe, Pu-Ta, and Pu-Si alloys

    SciTech Connect

    Rizzo, H.F.; Echeverria, A.W.

    1985-08-20

    Sputter deposition technique was used to study the possible formation of amorphous structures in Pu-Fe, Pu-Ta, and Pu-Si systems. A triode sputtering system was used to prepare sputtered coatings: 13 to 59 at. % (a/o) Fe, 10 to 50 a/o Si, and 15 to 65 a/o Ta. Structure of the coatings was determined by x-ray diffraction techniques. The temperature stability of the obtained structures was determined by Differential Scanning Calorimetry (DSC) measurements. The Pu-Fe and Pu-Si binary systems showed strong evidence for the formation of amorphous phases in the sputtered coatings. X-ray analyses indicated the presence of Pu6Fe in the 13 to 20 a/o Fe range of Pu-Fe alloys and no apparent crystalline phases over the entire 10 to 50 a/o Si range of Pu-Si alloys. In the Pu-Ta system, the DSC data obtained for compositions below 50 a/o Ta did not show typical crystallization exotherms. At compositions above 50 a/o Ta, a metastable bcc alpha Ta structure was observed with an expanded lattice parameter. The calculated volume expansion (2.9%) corresponds to 29 a/o of Pu in solid solution if the lattice parameter is assumed to follow Vegards Law. After storage in a nitrogen glovebox atmosphere for over two years, the Pu-Si and Pu-Ta coatings have maintained a metallic luster and have shown no visible evidence of surface oxidation.

  6. Leather material found on a 6th B.C. Chinese bronze sword: A technical study

    NASA Astrophysics Data System (ADS)

    Luo, Wugan; Si, Yi; Wang, Hongmin; Qin, Ying; Huang, Fengchun; Wang, Changsui

    2011-09-01

    During July to November, 2006, an important archaeological excavation was conducted in Yun country, Hubei province, southern China. Chinese archaeologists found some remnant of leather materials, covered with red pigments, on a 6th century B.C. Chinese bronze sword. To understand the technology/ies that may have been utilized for manufacturing the leathers, a combined of Raman spectroscopy, FT-IR and XRF was thus applied to the remnant of leather materials. Raman analyses showed that red pigment on the leather was cinnabar (HgS). FT-IR and XRF analyses indicated that the content of some elements, such as Ca (existing as CaCO 3) and Fe (existing as Fe 2O 3), were much higher than those in the surrounding grave soil. The results inferred an application of lime depilation and retting, and the Fe-Al compound salt as tanning agent. And it was furthermore implicated that the Fe-Al salt tanning technique had been developed in the middle and late Spring and Autumn Period of China.

  7. 6th Circuit: insurance policies are not covered by the ADA.

    PubMed

    1997-08-22

    The 6th U.S. Circuit Court of Appeals ruled that Title III of the Americans with Disabilities Act (ADA) does not cover the products that an insurer offers. The ADA only covers the physical premises of an insurance company. The court also ruled that the ADA does not mandate equality in employer-provider insurance coverage between people with varying types of disabilities. According to the court, the ADA only requires that all eligible employees be able to enroll in the plan. The case was brought by [name removed], a former employee of Schering-Plough Corporation, who complained that the long-term disability plan sponsored by the company and operated by Metropolitan Life Insurance Company, violated the ADA. The plan limited mental illness disability benefits to two years but did not place a similar cap on physical conditions. The ruling, binding in Tennessee, Kentucky, Ohio, and Michigan, contradicts earlier opinions which held that insurance products are subject to Title III of the ADA. The ruling states that Title III does not control the content of a long-term disability policy offered by an employer. Previous precedents set by the 1st Circuit Court in 1994 that had been viewed as protecting persons living with AIDS (PWAs) from discrimination in insurance programs and products were rejected by this ruling.

  8. Prevention and Treatment of Cancer: Hypes and Hopes 6th International Translational Cancer Research Conference.

    PubMed

    Patel, Prabhudas; Vora, Hemangini; Aggarwal, Bharat B; Gandhi, Varsha; Mehta, Kapil; Pathak, Sen

    2016-09-01

    Cancer is primarily an "old-age" disease that has an "age-old" history. The overall incidence of cancer is much higher in Western countries, but is rapidly growing in Eastern countries perhaps due to change in life-style. Almost three million studies published to date indicate that cancer is a hyperproliferative disorder that arises from dysregulation of multiple cell signaling pathways. The cancer genome landscape indicates that approximately 140 genes and 12 cell signaling pathways drive almost all cancers. "Targeted therapy," a buzz word in cancer treatment for the past two decades, has provided antibodies, as well as small-molecule inhibitors. These therapies have been successful only in few instances. However, in most cases, minor increase in overall survival has been reported at the cost of huge expense. An alternative strategy is to prevent cancer or to diagnose and treat the disease at an early stage to gain survival benefits. Such interventions are also cost-effective. To address some of these issues, the 6th International Translational Cancer Research Conference was held during February 4-7th, 2016, in Ahmedabad, Gujarat, India; the homeland of Mahatma Gandhi. This conference was focused on utilizing multidisciplinary approaches for prevention and early treatment that would likely simultaneously or sequentially target many key pathways. Several distinguished speakers were invited from around the world. This article highlights primary features of this conference. PMID:27630358

  9. [Psychometric performance of the 6th version of the Addiction Severity Index in Spanish (ASI-6)].

    PubMed

    Díaz Mesa, Eva M; García-Portilla, Paz; Sáiz, Pilar A; Bobes Bascarán, Teresa; Casares, María José; Fonseca, Eduardo; Carreño, Eduardo; Flórez, Gerardo; Guardia, Josep; Ochoa, Enriqueta; Pereiro, César; Rubio, Gabriel; Terán, Antonio; Fernández Hermida, José Ramón; Bobes, Julio

    2010-08-01

    This work analysed the psychometric properties of the 6th version of the Addiction Severity Index (ASI-6) translated and adapted to the Spanish language. A multicentre, observational and prospective design was used. A total of 258 participants were included, 217 were patients (35 stable patients and 182 unstable patients), and 41 were controls. The results show satisfactory psychometric performance of the ASI-6. The degree of the internal consistency of the standardized objective scores ranged between .47 and .95. As for test-retest reliability, the values were acceptable, varying from .36 to 1. The study of the internal structure revealed a good fit to a unidimensional solution for all scales taken independently. Regarding convergent-discriminant validity, the correlations between the primary and secondary scales of the ASI-6 and the Clinic Global Impression score were low, with values from .01 to .26. Likewise, 8 of the 15 scales differentiated between controls and unstable patients. The psychometric properties of the ASI-6 Spanish version seem to be acceptable, though it is necessary to carry out new studies to test metric quality with independent samples of patients.

  10. FOREWORD: 6th International Symposium on Electronic Beam Ion Sources and their Applications

    NASA Astrophysics Data System (ADS)

    Liljeby, L.

    1997-01-01

    The 6th International Symposium on Electron Beam Ion sources and their Applications was held at the Manne Siegbahn Laboratory at Stockholm University, June 20-23, 1994. A symposium in this series is held every three years. The next one will be organised by Professor Reinhard Becker at the J. W. Goethe University in Frankfurt am Main, Germany. The Stockholm symposium had a total of 65 participants from 9 countries. 43 oral presentations were given and 7 posters were exhibited. For the first time in this series the proceedings have been refereed. The symposium was given generous support by the Marcus Wallbenberg Foundation for International Co-operation in Science, a support mainly used for inviting delegates from Russia and students. The organisation of the symposium was led by Dr. Carl Johan Herrlander. His efficiency, organising skill and never ending attention to all the aspects of the symposium were of the utmost importance for carrying it through. We deeply regret that the proceedings have been very much delayed. Physica Scripta has no part in causing the delay which is solely a result of my inability to enforce deadlines. We think though that the contents still is of interest in particular as a full documentation of the conference.

  11. Comparing independent observations at the time of Abruzzo April 6th 2009 earthquake

    NASA Astrophysics Data System (ADS)

    Tramutoli, Valerio; Corrado, Rosita; Pia Faruolo, Maria; Filizzola, Carolina; Genzano, Nicola; Grimaldi, Caterina Livia Sara; Lacava, Teodosio; Lisi, Mariano; Mazzeo, Giuseppe; Pergola, Nicola

    2010-05-01

    The idea that EQs have no precursors at all (that seems to justify purely statistical EQ forecast approaches based only on the analysis of seismic data) has discouraged for long time the investments in multi-parametric observation networks and related research activities. Even if never demonstrated such assumptions have been not without consequences. For instance, even in presence of several months long seismic crisis, most of the observations available for the Abruzzo April 6th 2009 earthquake are concentrated in the co-post seismic phases and relatively poor (mainly due to occasional/individual researchers initiatives) are the observational data collected in the pre-event phase. In this very particular scientific context satellite sensors offering continuity of Earth Observation at the global scale can play a particularly important role. In this work results achieved by applying the general RST (Robust Satellite Technique) approach to 30 years of different satellite thermal infrared data (NOAA-AVHRR, EOS-MODIS, MSG-SEVIRI) during the Abruzzo March-April 2009 seismic sequence will be discussed also for comparison with other ground based observation performed before and after the main shock in order to understand if a careful analysis of independent observations, also in this field, can produce (at least) some small improvements of our knowledge on EQ preparatory phases.

  12. Prevention and Treatment of Cancer: Hypes and Hopes 6th International Translational Cancer Research Conference.

    PubMed

    Patel, Prabhudas; Vora, Hemangini; Aggarwal, Bharat B; Gandhi, Varsha; Mehta, Kapil; Pathak, Sen

    2016-09-01

    Cancer is primarily an "old-age" disease that has an "age-old" history. The overall incidence of cancer is much higher in Western countries, but is rapidly growing in Eastern countries perhaps due to change in life-style. Almost three million studies published to date indicate that cancer is a hyperproliferative disorder that arises from dysregulation of multiple cell signaling pathways. The cancer genome landscape indicates that approximately 140 genes and 12 cell signaling pathways drive almost all cancers. "Targeted therapy," a buzz word in cancer treatment for the past two decades, has provided antibodies, as well as small-molecule inhibitors. These therapies have been successful only in few instances. However, in most cases, minor increase in overall survival has been reported at the cost of huge expense. An alternative strategy is to prevent cancer or to diagnose and treat the disease at an early stage to gain survival benefits. Such interventions are also cost-effective. To address some of these issues, the 6th International Translational Cancer Research Conference was held during February 4-7th, 2016, in Ahmedabad, Gujarat, India; the homeland of Mahatma Gandhi. This conference was focused on utilizing multidisciplinary approaches for prevention and early treatment that would likely simultaneously or sequentially target many key pathways. Several distinguished speakers were invited from around the world. This article highlights primary features of this conference.

  13. A school-based, peer leadership physical activity intervention for 6th graders

    PubMed Central

    Barr-Anderson, Daheia J.; Laska, Melissa N.; Veblen-Mortenson, Sara; Dudovitz, Bonnie; Farbarksh, Kian; Story, Mary

    2012-01-01

    Background The aim of this study was to promote physical activity in 6th graders by developing and testing the feasibility of an enhanced Presidential Active Lifestyle Award (PALA) program comprised of a peer leadership component and innovative exercise resource toolkit including DVDs. Method A racially/ethnically diverse sample of students received the standard PALA program (2 control schools, n=61) or enhanced PALA+Peers program (2 intervention schools, n=87) during 2006–2007 academic year. Results Compared to the control condition, the intervention was successful in increasing moderate physical activity in all students (p=0.02) and moderate and hard physical activity among girls (p=0.03 and p=0.04, respectively). Teachers and students reported a high level of satisfaction and receptivity with the intervention. All teachers thought the DVDs were well-received, and 87% of students reported that they would recommend the enhanced program to peers. Conclusion Coupling peer leadership and DVDs that promote physical activity may be an effective way to increase youth physical activity. PMID:21945980

  14. Biodegradation of PuEDTA and Impacts on Pu Mobility

    SciTech Connect

    Bolton, H., Jr.; Rai, D.; Xun, L.

    2004-03-17

    The contamination of many DOE sites by Pu presents a long-term problem because of its long half-life (240,000 yrs) and the low drinking water standard (<10{sup -12} M). EDTA was co-disposed with radionuclides (e.g., Pu, {sup 60}Co), formed strong complexes, and enhanced radionuclide transport at several DOE sites. Biodegradation of EDTA should decrease Pu mobility. One objective of this project was to determine the biodegradation of EDTA in the presence of PuEDTA complexes. The aqueous system investigated at pH 7 (10{sup -4} M EDTA and 10{sup -6} M Pu) contained predominantly Pu(OH){sub 2}EDTA{sup 2-}. The EDTA was degraded at a faster rate in the presence of Pu. As the total concentration of both EDTA and PuEDTA decreased (i.e., 10{sup -5} M EDTA and 10{sup -7} M PuEDTA), the presence of Pu decreased the biodegradation rate of the EDTA. It is currently unclear why the concentration of Pu directly affects the increase/decrease in rate of EDTA biodegradation. The soluble Pu concentration decreased, in agreement with thermodynamic predictions, as the EDTA was biodegraded, indicating that biodegradation of EDTA will decrease Pu mobility when the Pu is initially present as Pu(IV)EDTA. A second objective was to investigate how the presence of competing metals, commonly encountered in geologic media, will influence the speciation and biodegradation of Pu(IV)-EDTA. Studies on the solubilities of Fe(OH){sub 3}(s) and of Fe(OH){sub 3}(s) plus PuO{sub 2}(am) in the presence of EDTA and as a function of pH showed that Fe(III) out competes the Pu(IV) for the EDTA complex, thereby showing that Pu(IV) will not form stable complexes with EDTA for enhanced transport of Pu in Fe(III) dominated subsurface systems. A third objective is to investigate the genes and enzymes involved in EDTA biodegradation. BNC1 can use EDTA and another synthetic chelating agent nitrilotriacetate (NTA) as sole carbon and nitrogen sources. The same catabolic enzymes are responsible for both EDTA and NTA

  15. Elastic properties of Pu metal and Pu-Ga alloys

    SciTech Connect

    Soderlind, P; Landa, A; Klepeis, J E; Suzuki, Y; Migliori, A

    2010-01-05

    We present elastic properties, theoretical and experimental, of Pu metal and Pu-Ga ({delta}) alloys together with ab initio equilibrium equation-of-state for these systems. For the theoretical treatment we employ density-functional theory in conjunction with spin-orbit coupling and orbital polarization for the metal and coherent-potential approximation for the alloys. Pu and Pu-Ga alloys are also investigated experimentally using resonant ultrasound spectroscopy. We show that orbital correlations become more important proceeding from {alpha} {yields} {beta} {yields} {gamma} plutonium, thus suggesting increasing f-electron correlation (localization). For the {delta}-Pu-Ga alloys we find a softening with larger Ga content, i.e., atomic volume, bulk modulus, and elastic constants, suggest a weakened chemical bonding with addition of Ga. Our measurements confirm qualitatively the theory but uncertainties remain when comparing the model with experiments.

  16. Elastic properties of Pu metal and Pu-Ga alloys

    NASA Astrophysics Data System (ADS)

    Söderlind, Per; Landa, Alex; Klepeis, J. E.; Suzuki, Y.; Migliori, A.

    2010-06-01

    We present elastic properties, theoretical and experimental, of Pu metal and Pu-Ga (δ) alloys together with ab initio equilibrium equation of state for these systems. For the theoretical treatment we employ density-functional theory in conjunction with spin-orbit coupling and orbital polarization for the metal and coherent-potential approximation for the alloys. Pu and Pu-Ga alloys are also investigated experimentally using resonant ultrasound spectroscopy. We show that orbital correlations become more important proceeding from α→β→γ plutonium, thus suggesting increasing f -electron correlation and a corresponding softening of the elastic moduli. For the δ-Pu-Ga alloys we find a softening with larger Ga content, i.e., atomic volume, bulk modulus, and elastic constants imply a weakened chemical bonding with addition of Ga. Our measurements confirm qualitatively the theory but uncertainties remain when comparing the model with experiments.

  17. PREFACE: 6th International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics

    NASA Astrophysics Data System (ADS)

    Fring, Andreas; Jones, Hugh; Znojil, Miloslav

    2008-06-01

    Attempts to understand the quantum mechanics of non-Hermitian Hamiltonian systems can be traced back to the early days, one example being Heisenberg's endeavour to formulate a consistent model involving an indefinite metric. Over the years non-Hermitian Hamiltonians whose spectra were believed to be real have appeared from time to time in the literature, for instance in the study of strong interactions at high energies via Regge models, in condensed matter physics in the context of the XXZ-spin chain, in interacting boson models in nuclear physics, in integrable quantum field theories as Toda field theories with complex coupling constants, and also very recently in a field theoretical scenario in the quantization procedure of strings on an AdS5 x S5 background. Concrete experimental realizations of these types of systems in the form of optical lattices have been proposed in 2007. In the area of mathematical physics similar non-systematic results appeared sporadically over the years. However, intensive and more systematic investigation of these types of non- Hermitian Hamiltonians with real eigenvalue spectra only began about ten years ago, when the surprising discovery was made that a large class of one-particle systems perturbed by a simple non-Hermitian potential term possesses a real energy spectrum. Since then regular international workshops devoted to this theme have taken place. This special issue is centred around the 6th International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics held in July 2007 at City University London. All the contributions contain significant new results or alternatively provide a survey of the state of the art of the subject or a critical assessment of the present understanding of the topic and a discussion of open problems. Original contributions from non-participants were also invited. Meanwhile many interesting results have been obtained and consensus has been reached on various central conceptual issues in the

  18. PREFACE: 6th Workshop on Infrared Spectroscopy and Microscopy with Accelerator-Based Sources (WIRMS11)

    NASA Astrophysics Data System (ADS)

    Lupi, Stefano; Perucchi, Andrea

    2012-05-01

    This volume of Journal of Physics: Conference Series is dedicated to a subset of papers related to the work presented at the 6th edition of the international Workshop on Infrared Spectroscopy and Microscopy with Accelerator-Based Sources (WIRMS), held in Trieste, Italy, September 4-8 2011. Previous editions of the conference were held in Porquerolles (France), Lake Tahoe (USA), Rathen (Germany), Awaji (Japan), and Banff (Canada). This edition was organized and chaired by Stefano Lupi (Roma La Sapienza) and co-chaired by Andrea Perucchi (Elettra), with the support of the Italian Synchrotron Light Laboratory ELETTRA, which was honored to host the WIRMS workshop in its tenth anniversary. The 6th WIRMS edition addressed several different topics, ranging from biochemistry to strongly correlated materials, from geology to conservation science, and from forensics to the study of cometary dusts. Representatives from the infrared scientific programs at synchrotron light sources and free-electron-laser facilities. This edition was attended by 88 participants, including representatives from the infrared scientific programs at synchrotron light sources and free-electron-laser facilities, who enjoyed the stimulating scientific presentations, several detailed discussions, and the beautiful weather and scenery of the Trieste gulf. Participants came from 16 different nations and four continents, including many young scientists, six of which were supported by the organizers. There were 45 scientific talks divided in 11 sessions: Facilities, Microspectroscopy (I, II, III), Time-Resolved Spectroscopies, Extreme Conditions, Condensed Matter, Near-Field, Imaging, THz Techniques and High-Resolution Spectroscopy. 37 posters were also presented at two very lively evening poster sessions. We would like to use the opportunity of writing this preface to thank all the participants of the workshop for the very high level of their scientific contribution and for the very friendly atmosphere

  19. Probiotic amelioration of azotemia in 5/6th nephrectomized Sprague-Dawley rats.

    PubMed

    Ranganathan, Natarajan; Patel, Beena; Ranganathan, Pari; Marczely, Joseph; Dheer, Rahul; Chordia, Tushar; Dunn, Stephen R; Friedman, Eli A

    2005-08-24

    The present study was to test the hypothesis that, selected bacteria instilled into the gastrointestinal tract could help in converting nitrogenous wastes accumulated due to renal insufficiency into non-toxic compounds; thereby, ameliorating the biochemical imbalance. Herein we describe a prospective, blinded, placebo controlled pilot-study, using 5/6th nephrectomized Sprague Dawley rat, as a chronic renal failure model. The study group consisted of 36 nephrectomized and 7 non-nephrectomized (control) rats. After two-week nephrectomy stabilization, cohorts of six nephrectomized rats were fed casein-based diet plus one of the following regimens: (A) Control, (B) Placebo (casein-based diet without probiotics), (C) Bacillus pasteurii, (D) Sporolac(R), (E) Kibow cocktail, (F) CHR Hansen Cocktail, and (G) ECONORM. Subsequently, blood (retro-orbital) and urine (collected for measurements of blood urea-nitrogen and creatinine respectively), body weight and bacterial counts (feces) were obtained at regular intervals. The study end-points were to determine if any of the probiotic dietary supplements facilitated, (1) decreased blood concentrations of uremic toxins, (2) altered renal function, and (3) prolonged survival. After 16 weeks of treatment, regimens C and D significantly prolonged the life span of uremic rats, in addition to showing a reduction in blood urea-nitrogen levels, concluding that supplementation of probiotic formulation to uremic rats slows the progression of azotemia, which may correlate with prolonged life span of uremic rats. Derivative trials of probiotic treatment of larger animals and humans will further assess the potential role of probiotic formulations in delaying the onset and clinical severity of clinical illness at different stages of renal failure. PMID:16127597

  20. Designing Pu600 for Authentication

    SciTech Connect

    White, G

    2008-07-10

    Many recent Non-proliferation and Arms Control software projects include an authentication component. Demonstrating assurance that software and hardware performs as expected without hidden 'back-doors' is crucial to a project's success. In this context, 'authentication' is defined as determining that the system performs only its intended purpose and performs that purpose correctly and reliably over many years. Pu600 is a mature software solution for determining the presence of Pu and the ratio of Pu240 to Pu239 by analyzing the gamma ray spectra in the 600 KeV region. The project's goals are to explore hardware and software technologies which can by applied to Pu600 which ease the authentication of a complete, end-to-end solution. We will discuss alternatives and give the current status of our work.

  1. Story Telling: Research and Action to Improve 6th Grade Students' Views about Certain Aspects of Nature of Science

    ERIC Educational Resources Information Center

    Kahraman, Feray; Karatas, Faik Özgür

    2015-01-01

    This study is a four-week section of ongoing attempts that aim to improve 6th grade students' understandings of the nature of science. The study was carried out in a sixth grade science and technology class at a rural middle school with 15 students on the basis of action research methodology. During the study, four different stories based on the…

  2. Assessment of 6th Grade Elementary School Students, Their Parents' and Branch Teachers' Perspective on Physical Education Classes

    ERIC Educational Resources Information Center

    Boyraz, Sirin; Ozbar, Nurper; Yetgin, Meral Kucuk; Koksalan, Burke

    2015-01-01

    A total of 437 volunteers including 54 teachers, 218 6th grade students and 102 parents from Beykoz Elementary Schools participated in this study to understand the perspectives of students, families and teachers on Physical Education classes. The perspectives of students, families and teachers of other branches are identified by survey method.…

  3. Primary School English Teachers' Perceptions of the English Language Curriculum of 6th, 7th and 8th Grades

    ERIC Educational Resources Information Center

    Ersen Yanik, Asli

    2008-01-01

    This study aims to investigate how the teachers who have different background characteristics perceive the goals and content of the English language curriculum implemented at the 6th, 7th and 8th grades of public primary schools. The study was conducted during the 2004-2005 school year with 368 English teachers selected from the seven regions of…

  4. Comparing Science Learning among 4th-, 5th-, and 6th-Grade Students: STS versus Textbook-Based Instruction

    ERIC Educational Resources Information Center

    Yager, Robert E.; Choi, AeRan; Yager, Stuart O.; Akcay, Hakan

    2009-01-01

    Fifteen 4th-, 5th-, and 6th-grade teachers from five school districts each taught two sections of science--one with a Science-Technology-Society (STS) approach and the other with a more traditional textbook approach in which basic science concepts were the major organizers. Local, current, and personally relevant issues provided the context and…

  5. Process Evaluation of "Learn Young, Learn Fair": A Stress Management Programme for 5th and 6th Graders

    ERIC Educational Resources Information Center

    Kraag, Gerda; Van Breukelen, Gerard; Lamberts, Petra; Vugts, Odette; Kok, Gerjo; Fekkes, Minne; Abu-Saad, Huda Huijer

    2007-01-01

    This article describes the process evaluation of a stress management program called "Learn Young, Learn Fair" for 5th and 6th graders. Studies, reviews and meta-analyses of prevention programs report that a common limitation in studies is the restricted documentation of process factors that contribute to the success of interventions. Program…

  6. Proceedings from the 6th Annual University of Calgary Leaders in Medicine Research Symposium.

    PubMed

    Roberts, Jodie I; Beatty, Jennifer K; Peplowski, Michael A; Keough, Michael B; Yipp, Bryan G; Hollenberg, Morley D; Beck, Paul L

    2015-01-01

    On November 14, 2014, the Leaders in Medicine (LIM) program at the Cumming School of Medicine, University of Calgary hosted its 6th Annual Research Symposium. Dr. Danuta Skowronski, Epidemiology Lead for Influenza and Emerging Respiratory Pathogens at the British Columbia Centre for Disease Control (BCCDC), was the keynote speaker and presented a lecture entitled "Rapid response research during emerging public health crises: influenza and reflections from the five year anniversary of the 2009 pandemic". The LIM symposium provides a forum for both LIM and non-LIM medical students to present their research work, either as an oral or poster presentation. There were a total of six oral presentations and 77 posters presented. 
The oral presentations included: Swathi Damaraju, "The role of cell communication and 3D Cell-Matrix environment in a stem cell-based tissue engineering strategy for bone repair"; Menglin Yang, "The proteolytic activity of Nepenthes pitcher fluid as a therapeutic for the treatment of celiac disease"; Amelia Kellar, "Monitoring pediatric inflammatory bowel disease - a retrospective analysis of transabdominal ultrasound"; Monica M. Faria-Crowder, "The design and application of a molecular profiling strategy to identify polymicrobial acute sepsis infections"; Waleed Rahmani, "Hair follicle dermal stem cells regenerate the dermal sheath, repopulate the dermal papilla and modulate hair type"; and, Laura Palmer, "A novel role for amyloid beta protein during hypoxia/ischemia". 
The article on the University of Calgary Leaders in Medicine Program, "A Prescription that Addresses the Decline of Basic Science Education in Medical School," in a previous issue of CIM (2014 37(5):E292) provides more details on the program. Briefly, the LIM Research Symposium has the following objectives: (1) to showcase the impressive variety of projects undertaken by students in the LIM Program as well as University of Calgary medical students; (2) to encourage medical

  7. Storm Peak Laboratory 5th-6th Grade Climate and Weather Program

    NASA Astrophysics Data System (ADS)

    McCubbin, I. B.; Hallar, A. G.

    2008-12-01

    science. At the end of the day each student has a data sheet with measurements recorded from 5 locations of different elevations to take back to the classroom. Following the field trip, SPL scientists and educators visit the school for a follow-up to help children grasp concepts, represent their data set collected in graphical formats, answer questions, and evaluate students" learning. Currently, approximately 250 students annually participate in the SPL 5th and 6th grade climate education program.

  8. Proceedings from the 6th Annual University of Calgary Leaders in Medicine Research Symposium.

    PubMed

    Roberts, Jodie I; Beatty, Jennifer K; Peplowski, Michael A; Keough, Michael B; Yipp, Bryan G; Hollenberg, Morley D; Beck, Paul L

    2015-01-01

    On November 14, 2014, the Leaders in Medicine (LIM) program at the Cumming School of Medicine, University of Calgary hosted its 6th Annual Research Symposium. Dr. Danuta Skowronski, Epidemiology Lead for Influenza and Emerging Respiratory Pathogens at the British Columbia Centre for Disease Control (BCCDC), was the keynote speaker and presented a lecture entitled "Rapid response research during emerging public health crises: influenza and reflections from the five year anniversary of the 2009 pandemic". The LIM symposium provides a forum for both LIM and non-LIM medical students to present their research work, either as an oral or poster presentation. There were a total of six oral presentations and 77 posters presented. 
The oral presentations included: Swathi Damaraju, "The role of cell communication and 3D Cell-Matrix environment in a stem cell-based tissue engineering strategy for bone repair"; Menglin Yang, "The proteolytic activity of Nepenthes pitcher fluid as a therapeutic for the treatment of celiac disease"; Amelia Kellar, "Monitoring pediatric inflammatory bowel disease - a retrospective analysis of transabdominal ultrasound"; Monica M. Faria-Crowder, "The design and application of a molecular profiling strategy to identify polymicrobial acute sepsis infections"; Waleed Rahmani, "Hair follicle dermal stem cells regenerate the dermal sheath, repopulate the dermal papilla and modulate hair type"; and, Laura Palmer, "A novel role for amyloid beta protein during hypoxia/ischemia". 
The article on the University of Calgary Leaders in Medicine Program, "A Prescription that Addresses the Decline of Basic Science Education in Medical School," in a previous issue of CIM (2014 37(5):E292) provides more details on the program. Briefly, the LIM Research Symposium has the following objectives: (1) to showcase the impressive variety of projects undertaken by students in the LIM Program as well as University of Calgary medical students; (2) to encourage medical

  9. Pu in coastal marine environments

    NASA Astrophysics Data System (ADS)

    Santschi, Peter H.; Li, Yuan-Hui; Bell, Joy J.; Trier, Robert M.; Kawtaluk, Kathy

    1980-12-01

    Analysis of water samples from the New York Bight area and Narragansett Bay reveals that a small fraction of the total Pu (probably Pu (III + IV) species) is continuously removed to the sediments at a rate similar to that of the particle-reactive isotope 228Th. A more "soluble" Pu species appears to be released at times from the sediments to the water column in these nearshore regions. Sediments in shallow areas of the New York Bight south of Rhode Island and Narragansett Bay have high Pu inventories and relatively deep penetration of this element, although the net sediment accumulation rate is generally low (<0.03 g/cm 2 yr). The high Pu inventories can be explained if both sediment resuspension and sediment mixing are assumed to be the major controlling factors for the effective transfer of Pu from the water column to the sediments. By simultaneous modelling of the depth distribution of three tracers which operate on vastly different time scales: 234Th (half-life 24 days), 210Pb (half-life 22 years) and 239,240Pu (introduced into the environment during the past 30 years), bioturbation rates ranging from 4 to 32 cm 2/yr in the surface mixed layer (5-10 cm thick) and from 0.3 to 2.5 cm 2/yr in the layer below (up to 40 cm thick) and net sediment accumulation rates of approximately zero to 0.14 g/cm 2 yr were calculated for these areas.

  10. PREFACE: 6th Vacuum and Surface Sciences Conference of Asia and Australia (VASSCAA-6)

    NASA Astrophysics Data System (ADS)

    Ahsan Bhatti, Javaid; Hussain, Talib; Khan, Wakil

    2013-06-01

    The Vacuum and Surface Sciences Conference of Asia and Australia (VASSCAA) conference series has been organized to create a new forum in Asia and Australia to discuss vacuum, surface and related sciences, techniques and applications. The conference series is officially endorsed by the International Union for Vacuum Science, Technique and Application (IUVSTA). The International Steering Committee of VASSCAA is comprised of Vacuum Societies in seven countries: Australia, China, India, Iran, Japan, South Korea and Pakistan. VASSCAA-1 was organized by the Vacuum Society of Japan in 1999 in Tokyo, Japan. VASSCAA-2 was held in 2002 in Hong Kong, VASSCAA-3 in Singapore in 2005. VASSCAA-4 was held in Matsue, Japan in 2008 and VASSCAA-5 in 2010 in Beijing, China. The 6th Vacuum and Surface Sciences Conference of Asia and Australia (VASSCAA-6) was held from 9-13 October 2012 in the beautiful city of Islamabad, Pakistan. The venue of the conference was the Pak-China Friendship Centre, Islamabad. More than six hundred local delgates and around seventy delegates from different countries participated in this mega event. These delegates included scientists, researchers, engineers, professors, plant operators, designers, vendors, industrialists, businessmen and students from various research organizations, technical institutions, universities, industries and companies from Pakistan and abroad. The focal point of the event was to enhance cooperation between Pakistan and the international community in the fields of vacuum, surface science and other applied technologies. At VASSCAA-6 85 oral presentations were delivered by local and foreign speakers. These were divided into different sessions according to their fields. A poster session was organized at which over 70 researchers and students displayed their posters. The best three posters won prizes. In parallel to the main conference sessions four technical short courses were held. The participants showed keen interest in all these

  11. Pu Anion Exchange Process Intensification

    SciTech Connect

    Taylor-Pashow, K.

    2015-10-08

    This project seeks to improve the efficiency of the plutonium anion-exchange process for purifying Pu through the development of alternate ion-exchange media. The objective of the project in FY15 was to develop and test a porous foam monolith material that could serve as a replacement for the current anion-exchange resin, Reillex® HPQ, used at the Savannah River Site (SRS) for purifying Pu. The new material provides advantages in efficiency over the current resin by the elimination of diffusive mass transport through large granular resin beads. By replacing the large resin beads with a porous foam there is much more efficient contact between the Pu solution and the anion-exchange sites present on the material. Several samples of a polystyrene based foam grafted with poly(4-vinylpyridine) were prepared and the Pu sorption was tested in batch contact tests.

  12. The Efficiency of Cluster Method in Improving the Creative Writing Skill of 6th Grade Students of Primary School

    ERIC Educational Resources Information Center

    Sahbaz, Namik Kemal; Duran, Gozde

    2011-01-01

    The aim of this research is to search the effect of the cluster method on the creative writing skill of 6th grade students. In this paper, the students of 6-A, studying at Ulas Primary School in 2010-2011 academic year, were divided into two groups as experiment and control. Taking into consideration the various variants, pre-test and last-test…

  13. Program Pu Futures 2006

    SciTech Connect

    Fluss, M

    2006-06-12

    The coordination chemistry of plutonium remains relatively unexplored. Thus, the fundamental coordination chemistry of plutonium is being studied using simple multi-dentate ligands with the intention that the information gleaned from these studies may be used in the future to develop plutonium-specific sequestering agents. Towards this goal, hard Lewis-base donors are used as model ligands. Maltol, an inexpensive natural product used in the commercial food industry, is an ideal ligand because it is an all-oxygen bidentate donor, has a rigid structure, and is of small enough size to impose little steric strain, allowing the coordination preferences of plutonium to be the deciding geometric factor. Additionally, maltol is the synthetic precursor of 3,4-HOPO, a siderophore-inspired bidentate moiety tested by us previously as a possible sequestering agent for plutonium under acidic conditions. As comparisons to the plutonium structure, Ce(IV) complexes of the same and related ligands were examined as well. Cerium(IV) complexes serve as good models for plutonium(IV) structures because Ce(IV) has the same ionic radius as Pu(IV) (0.94 {angstrom}). Plutonium(IV) maltol crystals were grown out of a methanol/water solution by slow evaporation to afford red crystals that were evaluated at the Advanced Light Source at Lawrence Berkeley National Laboratory using single crystal X-ray diffraction. Cerium(IV) complexes with maltol and bromomaltol were crystallized via slow evaporation of the mother liquor to afford tetragonal, black crystals. All three complexes crystallize in space group I4{sub 1}/a. The Ce(IV) complex is isostructural with the Pu(IV) complex, in which donating oxygens adopt a trigonal dodecahedral geometry around the metal with the maltol rings parallel to the crystallographic S{sub 4} axis and lying in a non-crystallographic mirror plane of D{sub 2d} molecular symmetry (Fig 1). The metal-oxygen bonds in both maltol complexes are equal to within 0.04 {angstrom

  14. PREFACE: 6th International Conference on Inverse Problems in Engineering: Theory and Practice

    NASA Astrophysics Data System (ADS)

    Bonnet, Marc

    2008-07-01

    The 6th International Conference on Inverse Problems in Engineering: Theory and Practice (ICIPE 2008) belongs to a successful series of conferences held up to now following a three-year cycle. Previous conferences took place in Palm Coast, Florida, USA (1993), Le Croisic, France (1996), Port Ludlow, Washington, USA (1999), Angra dos Reis, Brazil (2002), and Cambridge, UK (2005). The conference has its roots on the informal seminars organized by Professor J V Beck at Michigan State University, which were initiated in 1987. The organization of this Conference, which took place in Dourdan (Paris) France, 15-19 June 2008, was made possible through a joint effort by four research departments from four different universities: LEMTA (Laboratoire de Mécanique Théorique et Appliquée, Nancy-Université) LMS (Laboratoire de Mécanique des Solides, Ecole Polytechnique, Paris) LMAC (Laboratoire de Mathématiques Appliquées, UTC Compiègne) LTN (Laboratoire de Thermocinétique, Université de Nantes) It received support from three organizations: SFT (Société Française de Thermique: French Heat Transfer Association) ACSM (Association Calcul de Structures et Simulation : Computational Structural Mechanics Association) GdR Ondes - CNRS (`Waves' Network, French National Center for Scientific Research) The objective of the conference was to provide the opportunity for interaction and cross-fertilization between designers of inverse methods and practitioners. The delegates came from very different fields, such as applied mathematics, heat transfer, solid mechanics, tomography.... Consequently the sessions were organised along mostly methodological topics in order to facilitate interaction among participants who might not meet otherwise. The present proceedings, published in the Journal of Physics: Conference Series, gathers the four plenary invited lectures and the full-length versions of 103 presentations. The latter have been reviewed by the scientific committee (see

  15. PREFACE: 6th International Conference on Inverse Problems in Engineering: Theory and Practice

    NASA Astrophysics Data System (ADS)

    Bonnet, Marc

    2008-07-01

    The 6th International Conference on Inverse Problems in Engineering: Theory and Practice (ICIPE 2008) belongs to a successful series of conferences held up to now following a three-year cycle. Previous conferences took place in Palm Coast, Florida, USA (1993), Le Croisic, France (1996), Port Ludlow, Washington, USA (1999), Angra dos Reis, Brazil (2002), and Cambridge, UK (2005). The conference has its roots on the informal seminars organized by Professor J V Beck at Michigan State University, which were initiated in 1987. The organization of this Conference, which took place in Dourdan (Paris) France, 15-19 June 2008, was made possible through a joint effort by four research departments from four different universities: LEMTA (Laboratoire de Mécanique Théorique et Appliquée, Nancy-Université) LMS (Laboratoire de Mécanique des Solides, Ecole Polytechnique, Paris) LMAC (Laboratoire de Mathématiques Appliquées, UTC Compiègne) LTN (Laboratoire de Thermocinétique, Université de Nantes) It received support from three organizations: SFT (Société Française de Thermique: French Heat Transfer Association) ACSM (Association Calcul de Structures et Simulation : Computational Structural Mechanics Association) GdR Ondes - CNRS (`Waves' Network, French National Center for Scientific Research) The objective of the conference was to provide the opportunity for interaction and cross-fertilization between designers of inverse methods and practitioners. The delegates came from very different fields, such as applied mathematics, heat transfer, solid mechanics, tomography.... Consequently the sessions were organised along mostly methodological topics in order to facilitate interaction among participants who might not meet otherwise. The present proceedings, published in the Journal of Physics: Conference Series, gathers the four plenary invited lectures and the full-length versions of 103 presentations. The latter have been reviewed by the scientific committee (see

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

    PubMed

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin; Pan, Shaoming; Roos, Per

    2014-02-01

    This paper reports an analytical method for the determination of plutonium isotopes ((238)Pu, (239)Pu, (240)Pu, (241)Pu) 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 × 10(5) 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 values, revealing that the developed method for plutonium determination in environmental samples is reliable. The measurement results of (239+240)Pu by alpha spectrometry agreed very well with the sum of (239)Pu and (240)Pu measured by ICP-MS. ICP-MS can not only measure (239)Pu and (240)Pu separately but also (241)Pu. However, it is impossible to measure (238)Pu using ICP-MS in environmental samples even a decontamination factor as high as 10(6) for uranium was obtained by chemical separation. PMID:24401459

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

    PubMed

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin; Pan, Shaoming; Roos, Per

    2014-02-01

    This paper reports an analytical method for the determination of plutonium isotopes ((238)Pu, (239)Pu, (240)Pu, (241)Pu) 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 × 10(5) 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 values, revealing that the developed method for plutonium determination in environmental samples is reliable. The measurement results of (239+240)Pu by alpha spectrometry agreed very well with the sum of (239)Pu and (240)Pu measured by ICP-MS. ICP-MS can not only measure (239)Pu and (240)Pu separately but also (241)Pu. However, it is impossible to measure (238)Pu using ICP-MS in environmental samples even a decontamination factor as high as 10(6) for uranium was obtained by chemical separation.

  18. Wood - An Innovative Component of High-tech Products? 6th Wädenswil Day of Chemistry 2014.

    PubMed

    Heinzelmann, Elsbeth

    2014-10-01

    Wood is a multifunctional renewable material that could replace oil-based and other non-renewable resources in many applications. In the Swiss National Science Foundation project NFP 66, entitled 'Wood as a resource', researchers are attempting to find ways to use wood more efficiently in the future. The 6th Wädenswil Day of Chemistry, which was organised by the Institute of Chemistry and Biological Chemistry at Zurich University of Applied Sciences in Wädenswil, gave an overview of the innovative activities currently being undertaken in this field.

  19. Is the onset of the 6th century 'dark age' in Maya history related to explosive volcanism?

    NASA Astrophysics Data System (ADS)

    Nooren, Kees; Hoek, Wim Z.; Van der Plicht, Hans; Sigl, Michael; Galop, Didier; Torrescano-Valle, Nuria; Islebe, Gerald; Huizinga, Annika; Winkels, Tim; Middelkoop, Hans; Van Bergen, Manfred

    2016-04-01

    Maya societies in Southern Mexico, Guatemala and Belize experienced a 'dark age' during the second half of the 6th century. This period, also known as the 'Maya Hiatus', is characterized by cultural downturn, political instability and abandonment of many sites in the Central Maya Lowlands. Many theories have been postulated to explain the occurrence of this 'dark age' in Maya history. A possible key role of a large volcanic eruption in the onset of this 'dark age' will be discussed. Volcanic deposits recovered from the sedimentary archive of lake Tuspán and the Usumacinta-Grijalva delta were studied in detail and the combination of multiple dating techniques allowed the reconstruction of the timing of a large 6th century eruption. Volcanic glass shards were fingerprinted to indicate the source volcano and high resolution pollen records were constructed to indicate the environmental impact of the eruption. Results are compared with available archaeological data and causality with the disruption of Maya civilization will be evaluated.

  20. Economical Production of Pu-238

    SciTech Connect

    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.

  1. Distinguishing Pu Metal From Pu Oxide Using Fast Neutron Counting

    SciTech Connect

    Verbeke, J M; Chapline, G F; Nakae, L; Wurtz, R; Sheets, S

    2012-05-29

    We describe a method for simultaneously determining the {alpha}-ratio and k{sub eff} for fissile materials using fast neutrons. Our method is a generalization of the Hage-Cifarrelli method for determining k{sub eff} for fissile assemblies which utilizes the shape of the fast neutron spectrum. In this talk we illustrate the method using Monte Carlo simulations of the fast neutrons generated in PuO{sub 2} to calculate the fast neutron spectrum and Feynman correlations.

  2. IR and py/GC/MS examination of amber relics excavated from 6th century royal tomb in Korean Peninsula.

    PubMed

    Park, Jongseo; Yun, Eunyoung; Kang, Hyungtae; Ahn, Jooyoung; Kim, Gyuho

    2016-08-01

    Relics of amber were excavated from King Muryeong's tomb constructed in the 6th century on the Korean peninsula. To estimate the provenance, FTIR (Fourier transform infrared spectroscopy) and py/GC/MS (pyrolysis/gas chromatography/mass spectrometry) analysis were utilized. The reference Baltic amber sample was also analyzed with the same method for comparison. The relics were confirmed to be amber from the FTIR analysis where an absorption band near 1150cm(-1), characteristic one in Baltic amber, was also observed. In py/GC/MS analysis, pyrolyzed products like butanedioic acid and dehydroabietic acid, known constituents of amber, were observed. In addition, d-fenchyl alcohol, camphor, borneol and butanedioic acid, typical constituents of Baltic amber, were observed in some samples. From this, it appears that some of relics were made from Baltic amber and that Baltic amber was transported to the Korean peninsula in the time of tomb construction. PMID:27116473

  3. IR and py/GC/MS examination of amber relics excavated from 6th century royal tomb in Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Park, Jongseo; Yun, Eunyoung; Kang, Hyungtae; Ahn, Jooyoung; Kim, Gyuho

    2016-08-01

    Relics of amber were excavated from King Muryeong's tomb constructed in the 6th century on the Korean peninsula. To estimate the provenance, FTIR (Fourier transform infrared spectroscopy) and py/GC/MS (pyrolysis/gas chromatography/mass spectrometry) analysis were utilized. The reference Baltic amber sample was also analyzed with the same method for comparison. The relics were confirmed to be amber from the FTIR analysis where an absorption band near 1150 cm- 1, characteristic one in Baltic amber, was also observed. In py/GC/MS analysis, pyrolyzed products like butanedioic acid and dehydroabietic acid, known constituents of amber, were observed. In addition, D-fenchyl alcohol, camphor, borneol and butanedioic acid, typical constituents of Baltic amber, were observed in some samples. From this, it appears that some of relics were made from Baltic amber and that Baltic amber was transported to the Korean peninsula in the time of tomb construction.

  4. Robust Satellite Techniques (RST) for monitoring Earthquake active regions: the case of Abruzzo April 6th 2009 event. (Invited)

    NASA Astrophysics Data System (ADS)

    Pergola, N.; Aliano, C.; Corrado, R.; Genzano, N.; Lisi, M.; Mazzeo, G.; Tramutoli, V.; Coviello, I.; Filizzola, C.; Lacava, T.; Paciello, R.

    2009-12-01

    Space-time fluctuations of Earth’s emitted Thermal Infrared (TIR) radiation have been observed from satellite months to weeks before earthquakes occurrence. The general RST approach has been proposed in order to discriminate normal (i.e. related to the change of natural factor and/or observation conditions) TIR signal fluctuations from anomalous signal transients possibly associated to earthquake occurrence. In this work, the same approach is applied to the case of Abruzzo April 6th 2009 event (M=6.3) by using, for the first time: - the geostationary satellite MSG having improved spatial and temporal resolution - contemporary observations recorded by 3 independent satellite systems (NOAA-AVHRR, EOS-MODIS, MSG-SEVIRI) - a very long historical data set made of 30 years of satellite records. Preliminary results will be discussed also considering physical models that could explain the apparent correlation between anomalous space-time TIR transients and earthquake occurrence.

  5. 240Pu/239Pu mass ratio in environmental samples in Finland.

    PubMed

    Salminen-Paatero, S; Nygren, U; Paatero, J

    2012-11-01

    The (240)Pu/(239)Pu mass ratio was determined with SF-ICP-MS in lichen, peat, grass, air filter, and hot particle samples obtained in Finland. The main part of the air filters were sampled in northern Finland in 1963, whereas all the other samples were collected in southern and central Finland immediately after the Chernobyl accident in 1986. The (240)Pu/(239)Pu mass ratio varied between 0.13 ± 0.01 and 0.53 ± 0.03 in the environmental samples analyzed. The values for the (240)Pu/(239)Pu ratio confirm previous estimations, based on the (238)Pu/(239+240)Pu alpha activity ratio in the same samples, that global fallout from nuclear weapons testing and deposition from the Chernobyl accident have been the main Pu contamination sources in the environment in Finland. PMID:22776691

  6. Oxidation of Pu-bearing solids: A process for Pu recovery from Rocky Flats incinerator ash

    SciTech Connect

    Karraker, D.G.

    1997-07-18

    High-fired PuO{sub 2}, RFP ash heels, and synthetic RFP incinerator ash were easily soluble after oxidation of Pu(IV) to Pu(VI) by heating with Na{sub 2}O{sub 2} or KO{sub 2} to 450{degrees} for two hours. This offers a route to the recovery of Pu from these and similar PuO{sub 2}-bearing solids that can be carried out in present equipment. Evidence for new compounds K{sub 2}PuO{sub 4}, K{sub 4}PuO{sub 5} and K{sub 6}PuO{sub 6} is presented. A process for recovery of Pu from RFP incinerator ash is presented.

  7. Controls on Soluble Pu Concentrations in PuO2/Magnetite Suspensions

    SciTech Connect

    Felmy, Andrew R.; Moore, Dean A.; Pearce, Carolyn I.; Conradson, Steven D.; Qafoku, Odeta; Buck, Edgar C.; Rosso, Kevin M.; Ilton, Eugene S.

    2012-11-06

    Time-dependent reduction of PuO2(am) was studied over a range of pH values in the presence of aqueous Fe(II) and magnetite (Fe3O4) nanoparticles. At early time frames (up to 56 days) very little aqueous Pu was mobilized from PuO2(am), even though measured pH and redox potentials, coupled to equilibrium thermodynamic modeling indicated the potential for significant reduction of PuO2(am) to relatively soluble Pu(III). Introduction of Eu(III) or Nd(III) to the suspensions as competitive cations to displace possible sorbed Pu(III) resulted in the release of significant concentrations of aqueous Pu. However, the similarity of aqueous Pu concentrations that resulted from the introduction of Eu(III)/Nd(III) to suspensions with and without magnetite indicated that the Pu was displaced from the PuO2(am), not from magnetite. The fact that soluble forms of Pu can be displaced from the surface of PuO2(am) represents a potential, but previously unidentified, source of Pu to aqueous solution or subsurface groundwaters.

  8. Pu electronic structure and photoelectron spectroscopy

    SciTech Connect

    Joyce, John J; Durakiewicz, Tomasz; Graham, Kevin S; Bauer, Eric D; Moore, David P; Mitchell, Jeremy N; Kennison, John A; Martin, Richard L; Roy, Lindsay E; Scuseria, G. E.

    2010-01-01

    The electronic structure of PuCoGa{sub 5}, Pu metal, and PuO{sub 2} is explored using photoelectron spectroscopy. Ground state electronic properties are inferred from temperature dependent photoemission near the Fermi energy for Pu metal. Angle-resolved photoemission details the energy vs. crystaJ momentum landscape near the Fermi energy for PuCoGa{sub 5} which shows significant dispersion in the quasiparticle peak near the Fermi energy. For the Mott insulators AnO{sub 2}(An = U, Pu) the photoemission results are compared against hybrid functional calculations and the model prediction of a cross over from ionic to covalent bonding is found to be reasonable.

  9. Adsorption of Atmospheric Gases on Pu Surfaces

    SciTech Connect

    Nelson, A J; Holliday, K S; Stanford, J A; Grant, W K; Erler, R G; Allen, P G; McLean, W; Roussel, P

    2012-03-29

    Surface adsorption represents a competition between collision and scattering processes that depend on surface energy, surface structure and temperature. The surface reactivity of the actinides can add additional complexity due to radiological dissociation of the gas and electronic structure. Here we elucidate the chemical bonding of gas molecules adsorbed on Pu metal and oxide surfaces. Atmospheric gas reactions were studied at 190 and 300 K using x-ray photoelectron spectroscopy. Evolution of the Pu 4f and O 1s core-level states were studied as a function of gas dose rates to generate a set of Langmuir isotherms. Results show that the initial gas dose forms Pu{sub 2}O{sub 3} on the Pu metal surface followed by the formation of PuO{sub 2} resulting in a layered oxide structure. This work represents the first steps in determining the activation energy for adsorption of various atmospheric gases on Pu.

  10. Social and moral norm differences among Portuguese 1st and 6th year medical students towards their intention to comply with hand hygiene.

    PubMed

    Roberto, Magda S; Mearns, Kathryn; Silva, Silvia A

    2012-01-01

    This study examines social and moral norms towards the intention to comply with hand hygiene among Portuguese medical students from 1st and 6th years (N = 175; 121 from the 1st year, 54 from the 6th year). The study extended the theory of planned behaviour theoretical principles and hypothesised that both subjective and moral norms will be the best predictors of 1st and 6th year medical students' intention to comply with hand hygiene; however, these predictors ability to explain intention variance will change according to medical students' school year. Results indicated that the subjective norm, whose referent focuses on professors, is a relevant predictor of 1st year medical students' intention, while the subjective norm that emphasises the relevance of colleagues predicts the intentions of medical students from the 6th year. In terms of the moral norm, 6th year students' intention is better predicted by a norm that interferes with compliance; whereas intentions from 1st year students are better predicted by a norm that favours compliance. Implications of the findings highlight the importance of role models and mentors as key factors in teaching hand hygiene in medical undergraduate curricula. PMID:22111788

  11. Extinct 244Pu in Ancient Zircons

    NASA Astrophysics Data System (ADS)

    Turner, Grenville; Harrison, T. Mark; Holland, Greg; Mojzsis, Stephen J.; Gilmour, Jamie

    2004-10-01

    We have found evidence, in the form of fissiogenic xenon isotopes, for in situ decay of 244Pu in individual 4.1- to 4.2-billion-year-old zircons from the Jack Hills region of Western Australia. Because of its short half-life, 82 million years, 244Pu was extinct within 600 million years of Earth's formation. Detrital zircons are the only known relics to have survived from this period, and a study of their Pu geochemistry will allow us to date ancient metamorphic events and determine the terrestrial Pu/U ratio for comparison with the solar ratio.

  12. Leukemogenesis in heterozygous PU.1 knockout mice.

    PubMed

    Genik, Paula C; Vyazunova, Irina; Steffen, Leta S; Bacher, Jeffery W; Bielefeldt-Ohmann, Helle; McKercher, Scott; Ullrich, Robert L; Fallgren, Christina M; Weil, Michael M; Ray, F Andrew

    2014-09-01

    Most murine radiation-induced acute myeloid leukemias involve biallelic inactivation of the PU.1 gene, with one allele being lost through a radiation-induced chromosomal deletion and the other allele affected by a recurrent point mutation in codon 235 that is likely to be spontaneous. The short latencies of acute myeloid leukemias occurring in nonirradiated mice engineered with PU.1 conditional knockout or knockdown alleles suggest that once both copies of PU.1 have been lost any other steps involved in leukemogenesis occur rapidly. Yet, spontaneous acute myeloid leukemias have not been reported in mice heterozygous for a PU.1 knockout allele, an observation that conflicts with the understanding that the PU.1 codon 235 mutation is spontaneous. Here we describe experiments that show that the lack of spontaneous leukemia in PU.1 heterozygous knockout mice is not due to insufficient monitoring times or mouse numbers or the genetic background of the knockout mice. The results reveal that spontaneous leukemias that develop in mice of the mixed 129S2/SvPas and C57BL/6 background of knockout mice arise by a pathway that does not involve biallelic PU.1 mutation. In addition, the latency of radiation-induced leukemia in PU.1 heterozygous mice on a genetic background susceptible to radiation-induced leukemia indicates that the codon 235 mutation is not a rate-limiting step in radiation leukemogenesis driven by PU.1 loss.

  13. Ethical, legal, and social aspects of farm animal cloning in the 6th Framework Programme for Research.

    PubMed

    Claxton, John; Sachez, Elena; Matthiessen-Guyader, Line

    2004-01-01

    Cloned livestock have potential importance in the provision of improved medicine as well as in the development of livestock production. The public is, however, increasingly concerned about the social and ethical consequences of these advances in knowledge and techniques. There is unevenness throughout Europe in different Member States' attitudes to research into livestock cloning. Although there is EU legislation controlling the use of animals for research purposes, there is no legislation specifically governing cloning in livestock production. The main EU reference is the 9th Opinion of the European Group on Ethics, which states "Cloning of farm animals may prove to be of medical and agricultural as well as economic benefit. It is acceptable only when the aims and methods are ethically justified and when carried out under ethical conditions." The ethical justification includes the avoidance of suffering, the use of the 3Rs principle and a lack of better alternatives. The Commission addresses these issues in the 6th Framework Programme by promoting the integration of ethical, legal and social aspects in all proposals where they are relevant, by fostering ethical awareness and foresight in the proposals, by encouraging public dialogue, and by supporting specific actions to promote the debate. Research must respect fundamental ethical principles, including animal welfare requirements.

  14. Associations Between Home Environment and After-School Physical Activity and Sedentary Time Among 6th Grade Children.

    PubMed

    Lau, Erica Y; Barr-Anderson, Daheia J; Dowda, Marsha; Forthofer, Melinda; Saunders, Ruth P; Pate, Russell R

    2015-05-01

    This study examined associations of various elements of the home environment with after-school physical activity and sedentary time in 671 6th-grade children (Mage = 11.49 ± 0.5 years). Children's after-school total physical activity, moderate-to-vigorous physical activity, and sedentary time were measured by accelerometry. Parents completed surveys assessing elements of the home social and physical environment. Mixed-model regression analyses were used to examine the associations between each element of the home environment and children's after-school physical activity and sedentary time. Availability of home physical activity resources was associated positively with after-school total physical activity and negatively with after-school sedentary time in boys. Parental support was associated positively with after-school total physical activity and MVPA and negatively with after-school sedentary time in girls. The home physical environment was associated with boys' after-school physical activity and sedentary time, whereas the home social environment was associated with girls' after-school physical activity and sedentary time.

  15. Photometric and Spectroscopic Footprint Corrections in the Sloan Digital Sky Survey’s 6th Data Release

    NASA Astrophysics Data System (ADS)

    Specian, Mike A.; Szalay, Alex S.

    2016-04-01

    We identify and correct numerous errors within the photometric and spectroscopic footprints (SFs) of the Sloan Digital Sky Survey’s (SDSS) 6th data release (DR6). Within the SDSS’s boundaries hundreds of millions of objects have been detected. Yet we present evidence that the boundaries themselves contain a significant number of mistakes that are being revealed for the first time within this paper. Left unaddressed, these can introduce systematic biases into galaxy clustering statistics. Using the DR6 Main Galaxy Sample (MGS) targets as tracers, we reveal inconsistencies between the photometric and SF definitions provided in the Catalog Archive Server (CAS), and the measurements of targets therein. First, we find that 19.7 deg2 of the DR6 photometric footprint are devoid of MGS targets. In volumes of radii 7 {h}-1 {Mpc}, this can cause errors in the expected number of galaxies to exceed 60%. Second, we identify seven areas that were erroneously included or excluded from the SF. Moreover, the tiling algorithm that positioned spectroscopic fibers during and between DRs caused many areas along the edge of the SF to be significantly undersampled relative to the footprint’s interior. Through our corrections, we increase the completeness 2.2% by trimming 3.6% of the area from the existing SF. The sum total of these efforts has generated the most accurate description of the SDSS DR6 footprints ever created.

  16. Yersinia pestis DNA from skeletal remains from the 6(th) century AD reveals insights into Justinianic Plague.

    PubMed

    Harbeck, Michaela; Seifert, Lisa; Hänsch, Stephanie; Wagner, David M; Birdsell, Dawn; Parise, Katy L; Wiechmann, Ingrid; Grupe, Gisela; Thomas, Astrid; Keim, Paul; Zöller, Lothar; Bramanti, Barbara; Riehm, Julia M; Scholz, Holger C

    2013-01-01

    Yersinia pestis, the etiologic agent of the disease plague, has been implicated in three historical pandemics. These include the third pandemic of the 19(th) and 20(th) centuries, during which plague was spread around the world, and the second pandemic of the 14(th)-17(th) centuries, which included the infamous epidemic known as the Black Death. Previous studies have confirmed that Y. pestis caused these two more recent pandemics. However, a highly spirited debate still continues as to whether Y. pestis caused the so-called Justinianic Plague of the 6(th)-8(th) centuries AD. By analyzing ancient DNA in two independent ancient DNA laboratories, we confirmed unambiguously the presence of Y. pestis DNA in human skeletal remains from an Early Medieval cemetery. In addition, we narrowed the phylogenetic position of the responsible strain down to major branch 0 on the Y. pestis phylogeny, specifically between nodes N03 and N05. Our findings confirm that Y. pestis was responsible for the Justinianic Plague, which should end the controversy regarding the etiology of this pandemic. The first genotype of a Y. pestis strain that caused the Late Antique plague provides important information about the history of the plague bacillus and suggests that the first pandemic also originated in Asia, similar to the other two plague pandemics.

  17. New safe medicines faster: A proposal for a key action within the European union's 6th framework programme.

    PubMed

    Bjerrum, O J

    2000-01-01

    The global competitiveness of the European pharmaceutical industry is under threat. Technology currently available for the development of new medicines is unable to match the pace of drug discovery and design; and the ever-growing demand for safety, efficacy and quality documentation has increased the cost and time involved in getting new medicines on the market. Although the pharmaceutical industry is one of the strongest in Europe in terms of research, innovation, exports and employment, there are severe restrictions on its ability to create wealth and launch safe drugs for the treatment of common and rare afflictions. The present situation should not be allowed to continue. For this reason, the European Federation for Pharmaceutical Sciences (EUFEPS) has proposed a key action under the title "New safe medicines faster" for the forthcoming EU 6th RTD framework programme. The key action has three main objectives: to seek new technologies capable of more effective selection of potential drug candidates for innovative medicines while accommodating safety demands; to use such technologies to speed up the pharmaceutical development process and eliminate bottlenecks created by initial exploratory drug research; and to cultivate a pan-European interdisciplinary network that bridges the gap between industry, academia and regulatory authorities. By involving regulatory authorities early on and fuelling research and innovation with EU money it should be possible to create a new set of recognised European standards whereby new safe medicines can be brought onto the market faster and cheaper. PMID:10905750

  18. Effects of using relaxation breathing training to reduce music performance anxiety in 3rd to 6th graders.

    PubMed

    Su, Yu-Huei; Luh, Jer-Junn; Chen, Hsin-I; Lin, Chao-Chen; Liao, Miin-Jiun; Chen, Heng-Shuen

    2010-06-01

    The current study examined the effects of applying relaxation breathing training (RBT) as a means to reduce music performance anxiety (MPA) in young, talented musicians. A group of 59 young musicians from 3rd to 6th grade participated in this study, and all of them started RBT twice a week for 2 months prior to the examination. Four tests--2 mos, 1 mos, half an hour and 5 min before the examination--were conducted to examine the level of MPA after the application of RBT. Results show that the degree of MPA 5 min before the trial was lower than the degree of performance anxiety half an hour before the jury (t = -3.683, p < 0.01), which indicated that the RBT was associated with a decrease in MPA. Although a series of RBT exercises was applied, results indicated that when approaching the date of examination, the degree of performance anxiety still increased and reached its maximum half an hour before the jury. The recommendation for future studies is to combine the application of RBT with other methods to expand its effect in reducing MPA.

  19. Negative thermal ionization mass spectrometry of main group elements Part 2. 6th group: sulfur, selenium and tellurium

    NASA Astrophysics Data System (ADS)

    Wachsmann, M.; Heumann, K. G.

    1992-05-01

    A systematic investigation of the formation of negative ions for the 6th main group elements using negative thermal ionization mass spectrometry (NTI-MS) is presented. A double-filament ion source with BaO on the ionization filament has been applied to reduce the work function of the rhenium filament material. S[radical sign]-, Se[radical sign]- and Te[radical sign]- were produced as most abundant ions. Low intensities of SeO[radical sign]-, SeO[radical sign]-2, TeO[radical sign]- and TeO[radical sign]-2 have also been detected. Although the electron affinity of SO2 is low, high ion currents of SO[radical sign]-2 have been observed from BaSo4 samples. This may be due to an electron capture process of this molecule rather than to a thermal ionization process. A silica gel suspension mixed with the sample enhanced the Se[radical sign]- ion current by a factor of about 40 and the Te[radical sign]- intensity by a factor of about 10. However, the silica gel showed no enhancing effect on the S[radical sign]- ion current. An improvement in the precision of the selenium and tellurium isotope ratio measurements by a factor of up to 10 was obtained when using the silica gel technique as compared with previous NTI investigations. The data of the selenium isotope abundance measurements were accepted as "best measurements" by the IUPAC.

  20. Use of plutonium isotope activity ratios in dating recent sediments. [/sup 238/Pu//sup 239/Pu + /sup 240/Pu

    SciTech Connect

    Beasley, T. M.

    1982-01-01

    The majority of plutonium presently in the biosphere has come from the testing of nuclear devices. In the early 1950s, the Pu-238/239+240 activity ratio of fallout debris was > 0.04; in the more extensive test series of 1961 to 1962, the Pu-238/239+240 activity ratios were quite consistent at 0.02 to 0.03 and maximum fallout delivery occurred in mid-1963. A significant perturbation in Pu isotope activity ratios occurred in mid-1966 with the deposition of Pu-238 from the SNAP-9A reentry and burn-up. Recently deposited sediments have recorded these events and where accumulation rates are rapid (> 1 cm/y), changes in Pu isotope activity ratios can be used as a geochronological tool.

  1. Biodegradation of PuEDTA and Impacts on Pu Mobility

    SciTech Connect

    Xun, Luying; Bolton, Jr., Harvey

    2001-06-01

    Ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA) are synthetic chelating agents, which can form strong water-soluble complexes with radionuclides and metals and has been used to decontaminate and process nuclear materials. Synthetic chelating agents were co-disposed with radionuclides (e.g., 60Co, Pu) and heavy metals enhancing their transport in the subsurface. An understanding of EDTA biodegradation is essential to help mitigate enhanced radionuclide transport by EDTA. The objective of this research is to develop fundamental data on factors that govern the biodegradation of radionuclide-EDTA. These factors include the dominant EDTA aqueous species, the biodegradation of various metal-EDTA complexes, the uptake of various metal-EDTA complexes into the cell, the distribution and mobility of the radionuclide during and after EDTA biodegradation, and the enzymology and genetics of EDTA biodegradation.

  2. Probing the Pu4 + magnetic moment in PuF4 with 19F NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Capan, Cigdem; Dempsey, Richard J.; Sinkov, Sergey; McNamara, Bruce K.; Cho, Herman

    2016-06-01

    The magnetic fields produced by Pu4 + centers have been measured by 19F NMR spectroscopy to elucidate the Pu-F electronic interactions in polycrystalline PuF4. Spectra acquired at applied fields of 2.35 and 7.05 T reveal a linear scaling of the 19F line shape. A model is presented that treats the line broadening and shifts as due to dipolar fields produced by Pu valence electrons in localized noninteracting orbitals. Alternative explanations for the observed line shape involving covalent Pu-F bonding, superexchange interactions, and electronic configurations with enhanced magnetic moments are considered.

  3. Sonochemical redox reactions of Pu(III) and Pu(IV) in aqueous nitric solutions.

    PubMed

    Virot, Matthieu; Venault, Laurent; Moisy, Philippe; Nikitenko, Sergey I

    2015-02-14

    The behavior of Pu(iv) and Pu(iii) was investigated in aqueous nitric solutions under ultrasound irradiation (Ar, 20 kHz). In the absence of anti-nitrous reagents, ultrasound has no effect on Pu(iv), while Pu(iii) can be rapidly oxidized to Pu(iv) due to the autocatalytic formation of HNO(2) induced by HNO(3) sonolysis. In the presence of anti-nitrous reagents (sulfamic acid or hydrazinium nitrate), Pu(iv) can be sonochemically reduced to Pu(iii). The reduction follows a first order reaction law and leads to a steady state where Pu(iv) and Pu(iii) coexist in solution. The reduction process is attributed to the sonochemical generation of H(2)O(2) in solution. The kinetics attributed to the reduction of Pu(iv) are however higher than those related to the formation of H(2)O(2) which, after several hypotheses, is explained by the sonochemical erosion of the titanium-based sonotrode. Titanium particles thereby generated can be solubilized under ultrasound and generate Ti(iii) as an intermediate species, a strong reducing agent able to react with Pu(iv).

  4. Breakfast patterns among low-income, ethnically-diverse 4th-6th grade children in an urban area

    PubMed Central

    2014-01-01

    Background Increasing school breakfast participation has been advocated as a method to prevent childhood obesity. However, little is known about children’s breakfast patterns outside of school (e.g., home, corner store). Policies that increase school breakfast participation without an understanding of children’s breakfast habits outside of school may result in children consuming multiple breakfasts and may undermine efforts to prevent obesity. The aim of the current study was to describe morning food and drink consumption patterns among low-income, urban children and their associations with relative weight. Methods A cross-sectional analysis was conducted of data obtained from 651 4th-6th graders (51.7% female, 61.2% African American, 10.7 years) in 2012. Students completed surveys at school that included all foods eaten and their locations that morning. Height and weight were measured by trained research staff. Results On the day surveyed, 12.4% of youth reported not eating breakfast, 49.8% reported eating one breakfast, 25.5% reported eating two breakfasts, and 12.3% reported eating three or more breakfasts. The number of breakfasts consumed and BMI percentile showed a significant curvilinear relationship, with higher mean BMI percentiles observed among children who did not consume any breakfast and those who consumed ≥ 3 breakfasts. Sixth graders were significantly less likely to have consumed breakfast compared to younger children. A greater proportion of obese youth had no breakfast (18.0%) compared to healthy weight (10.1%) and overweight youth (10.7%, p = .01). Conclusions When promoting school breakfast, policies will need to be mindful of both over- and under-consumption to effectively address childhood obesity and food insecurity. Clinical trial registration NCT01924130 from http://clinicaltrials.gov/. PMID:24928474

  5. CfDS 2006: the 6th European Dark-Skies Symposium, Portsmouth, 2006 September 15-16

    NASA Astrophysics Data System (ADS)

    Mizon, R.

    2006-12-01

    The BAA's Campaign for Dark Skies took its turn in 2006 to stage the 6th European Dark-Skies Symposium, similar events having been held in previous years in Switzerland, Germany, France and Belgium. The event was the best attended to date, with more than 150 delegates from eleven European countries, the USA and even South Africa. Between sessions, delegates were given a tour of the night skies of the world in the South Downs Planetarium, where Dr John Mason simulated the effects of light pollution. This was followed by a visit to the Clanfield Observatory, courtesy of the Hampshire Astronomical Group, later in the evening, where the real night sky and a little real light pollution (!) were observed. The whole event was kindly sponsored by the BAA and Abacus Lighting Ltd. A principal aim of the two-day symposium was to advise planners and other decision-makers, and those who make, choose and install lighting, about the legal and moral issues surrounding light pollution. It is not, of course, the Campaign's intention to ban lighting, but to ensure that where outdoor lighting is required, it is designed and installed correctly, thereby causing little or no nuisance and reducing energy costs. These non-astronomical aspects were very much to the fore on the first day of the conference, which was opened by one of CfDS' best allies in Parliament, Lembit Opik MP. Mr Opik expressed his delight at seeing so many delegates, and confirmed his continuing support for the initiatives CfDS pursues within Parliament: for example its discussions with DEFRA on the subject of the proposed planning directive (PPS 23) on light pollution

  6. Comparing independent observations at the time of Abruzzo April 6th 2009 earthquake: new vs false ideas

    NASA Astrophysics Data System (ADS)

    Genzano, N.; Aliano, C.; Corrado, R.; Coviello, I.; Filizzola, C.; Lisi, M.; Lacava, T.; Martinelli, G.; Mazzeo, G.; Paciello, R.; Pergola, N.; Tramutoli, V.

    2009-12-01

    The discussion about earthquake precursors has been, since long time, biased by a number of assumptions not always scientifically funded and often not demonstrated at all. For instance an argument often used against the (claimed) existence of a precursor has been the lack of correlation between the relative intensity of the precursor signal and the magnitude of corresponding earthquake. The reason why such correlation “has to” exist in whatever condition, time and place, is still waiting for a scientific demonstration. But such assumptions are not without consequences. The idea that EQs have no precursors at all (that seems to justify approaches purely statistical based only on the analysis of seismic data) has discouraged for long time the European investments on multi-parametric observation networks and related research activities: so that even in presence of several months long seismic crisis (like the one culminated with the Abruzzo April 6th 2009 earthquake) most of the observational efforts remain concentrated in co-post seismic phases and relatively poor (mainly due to occasional/individual researchers initiatives) are the observational data-set available for the pre-event phase. In this context satellite sensors offering continuity of the Earth Observation at the global scale can play a particularly important role. In this work results achieved by applying the general RST approach to different satellite data (NOAA-AVHRR, EOS-MODIS, MSG-SEVIRI) during the Abruzzo March-April 2009 seismic sequence will be discussed also for comparison with other ground based observations performed before and after the main shock in order to understand if some new idea can substitute false assumptions helping to improve our knowledge on EQ preparatory phases.

  7. Distribution of nuclear bomb Pu in Nishiyama area, Nagasaki, estimated by accurate and precise determination of 240Pu/239Pu ratio in soils.

    PubMed

    Yoshida, S; Muramatsu, Y; Yamazaki, S; Ban-Nai, T

    2007-01-01

    Plutonium isotopes in forest soils collected in Nishiyama area, Nagasaki, were successfully determined by high resolution inductively coupled plasma mass spectrometry after the treatment with a microwave decomposition system. The (240)Pu/(239)Pu atom ratios observed in the samples in the Nishiyama area were obviously lower than the range of the global fallout. The low ratios (minimum 0.032) observed in Nishiyama area indicated the influence of detonation of the Pu nuclear weapon in 1945. Since the area is contaminated also by global fallout, the (240)Pu/(239)Pu atom ratio can be more sensitive indicator of bomb-derived Pu than Pu activity concentration.

  8. Comparing Traditional and Computer Assisted Education in the Teaching of Colour to 6th Grade Students and Determination of Its Retention

    ERIC Educational Resources Information Center

    Akengin, Gultekin

    2011-01-01

    In this study, informing 6th grade students on the subject of colour was taught using traditional and computer assisted education methods. Colour information was taught by the researcher for 5 weeks in order to specify the influence of both methods on students. The test, which was prepared at the beginning of the study and at the end of five-week…

  9. Trends in Substance Use among 6th-to 10th-Grade Students from 1998 to 2010: Findings from a National Probability Study

    ERIC Educational Resources Information Center

    Brooks-Russell, Ashley; Farhat, Tilda; Haynie, Denise; Simons-Morton, Bruce

    2014-01-01

    Of the handful of national studies tracking trends in adolescent substance use in the United States, only the Health Behavior in School-Aged Children (HBSC) study collects data from 6th through 10th graders. The purpose of this study was to examine trends from 1998 to 2010 (four time points) in the prevalence of tobacco, alcohol, and marijuana use…

  10. The Hetu'u Global Network: Measuring the Distance to the Sun Using the June 5th/6th Transit of Venus

    ERIC Educational Resources Information Center

    Faherty, Jacqueline K.; Rodriguez, David R.; Miller, Scott T.

    2012-01-01

    In the spirit of historic astronomical endeavors, we invited school groups across the globe to collaborate in a solar distance measurement using the rare June 5/6th transit of Venus. In total, we recruited 19 school groups spread over 6 continents and 10 countries to participate in our Hetu'u Global Network. Applying the methods of French…

  11. Proceedings of the Office of Special Education Programs' Annual Technical Assistance and Dissemination Meeting (6th, Washington, DC, January 16-18, 1996).

    ERIC Educational Resources Information Center

    Special Education Programs (ED/OSERS), Washington, DC.

    This document presents the proceedings for the Office of Special Education Programs' 6th Annual Technical Assistance and Dissemination Meeting held on January 16-18, 1996, in Washington, DC. Conference discussions centered around changing expectations for local and state education agencies and technical assistance and dissemination (TA&D)…

  12. Research into Higher Education 1970; Papers Presented at the Annual Conference of the Society for Research into Higher Education (6th).

    ERIC Educational Resources Information Center

    Society for Research into Higher Education, Ltd., London (England).

    This report presents three papers that were prepared for the 6th annual conference of the Society for Research into Higher Education, a London based organization. The 1st paper is "Factors Influencing Choice of Higher Education," by Margaret D. McCreath. She discusses part of an intensive study of the transition between school and higher education…

  13. US/Russian Joint Film Test

    NASA Technical Reports Server (NTRS)

    Slater, Richard

    1996-01-01

    A joint U.S./Russian film test was conducted during MIR Mission 18 to evaluate the effects of radiation on photographic film during long-duration space flights. Two duplicate sets of film were flown on this MIR mission: one set was processed and evaluated by the NASA/JSC Photographic Laboratory, and the other by the RKK Energia's Photographic Laboratory in Moscow. This preliminary report includes only the results of the JSC evaluation (excluding the SN-10 film which was not available for evaluation at the time this report was written). The final report will include an evaluation by JSC of the SN-10 film and an evaluation of the test data by the RKK Energia. ISC's evaluation of the test data showed the positive film flown was damaged very little when exposed to approximately 8 rads of radiation. Two of the three negative films were significantly damaged and the third film was damaged only moderately.

  14. US, Russian intelligence agencies offer proliferation assessments

    SciTech Connect

    Wolfsthal, J.B.

    1993-03-01

    The CIA outlined for the Senate Governmental Affairs Committee (February 24, 1993) the prospects for the spread of nuclear, chemical, and biological weapons and ballistic missiles in the aftermath of the Cold War. The testimony came less than one month after the Russian Foreign Intelligence Service released an 118-page report that also stressed the importance of preventing proliferation of weapons of mass destruction. CIA testimony and the FIS report both provided details on several states of proliferation concern, including North Korea, Iran, India, and Pakistan.

  15. Room-temperature electron spectroscopy of 239Pu and 240Pu

    NASA Astrophysics Data System (ADS)

    Ahmad, I.; Kondev, F. G.; Greene, J. P.; Zhu, S.

    2015-06-01

    Passivated, implanted, planar silicon (PIPS) detectors have been used for the measurement of electron spectra. The commercially available PIPS detectors, available in thicknesses of 100 μm, 300 μm, and 500 μm, have an energy resolution (FWHM) of ~ 2.2 keV, which is essentially the same as that of PIN diodes. Alpha and electron spectra of mass-separated 239Pu and 240Pu sources have been measured with a 300-μm thick PIPS detector and the electron to alpha ratios for the conversion lines of the 51.62- and 45.24-keV transitions have been determined. A procedure has been developed to determine the amount of 239Pu and 240Pu in a mixed source. The α-particle emission rate of the mixed source is measured, which is the sum of individual rates. From the electron spectrum of the mixed source, measured with the same setup as the alpha spectrum, the rates of 239Pu electron lines are determined. Using the electron rate of the 239Pu line and the electron to alpha ratio measured for the pure source, the α-particle emission rate of 239Pu is determined. The difference from the total α-particle emission rate gives the α-particle emission rate of 240Pu. In addition, electron intensities and conversion coefficients of the 239Pu and 240Pu transitions have been measured.

  16. Integration of physical activity and technology motion devices within a combined 5th and 6th grade science curriculum

    NASA Astrophysics Data System (ADS)

    Finn, Kevin Eugene

    Background: National recommendations to increase school-based physical activity and promote academic success advise incorporating movement into traditional classroom lessons. Classroom-based physical activities have favorable associations with indicators of cognitive functioning, academic behaviors, and academic achievement. Purpose: This study analyzed the Active Science framework, which incorporated school-based physical activity within interactive science classroom lessons. Specifically, the study measured the effects of the Active Science framework on student physical activity levels in the classroom, student learning of science inquiry skills and content knowledge, and student perceptions of physical activity and science. A secondary purpose was to evaluate the teachers' perceptions on the implementation of the framework. Subjects: Participants were 37 Hispanic girls (age=11.1 +/-0.8 yr) in mixed 5th/6th grade science classes in a private, urban middle school. Methods: Physical activity levels of the students during the Active Science framework were measured using pedometers and heart rate monitors. Pre- and post-tests were used to assess the levels of learning achieved by the students in science inquiry skills and content during the Active Science framework. Student perceptions and attitudes toward science and physical activity were measured during student focus groups and pre-post perception surveys. Lesson plan evaluations completed by the teachers and structured interviews provided data on implementation of the framework. Results: Physical activity results showed heart rate (146 +/-9 bpm); maximal heart rate (196 +/-10.6 bpm); time (35 +/-2.5 mins); steps (3050 +/-402.7); calories (99 +/-8.4 kcal); and distance (1.1 +/-0.2 miles) while performing the activity portion of the science lessons were consistent with national recommendations for accumulating school-based physical activity. Significant increases in science content and skills test scores with a 22

  17. Bone loss during partial weight bearing (1/6th gravity) is mitigated by resistance and aerobic exercise in mice

    NASA Astrophysics Data System (ADS)

    Boudreaux, R. D.; Metzger, C. E.; Macias, B. R.; Shirazi-Fard, Y.; Hogan, H. A.; Bloomfield, S. A.

    2014-06-01

    Astronauts on long duration missions continue to experience bone loss, as much as 1-2% each month, for up to 4.5 years after a mission. Mechanical loading of bone with exercise has been shown to increase bone formation, mass, and geometry. The aim of this study was to compare the efficacy of two exercise protocols during a period of reduced gravitational loading (1/6th body weight) in mice. Since muscle contractions via resistance exercise impart the largest physiological loads on the skeleton, we hypothesized that resistance training (via vertical tower climbing) would better protect against the deleterious musculoskeletal effects of reduced gravitational weight bearing when compared to endurance exercise (treadmill running). Young adult female BALB/cBYJ mice were randomly assigned to three groups: 1/6 g (G/6; n=6), 1/6 g with treadmill running (G/6+RUN; n=8), or 1/6 g with vertical tower climbing (G/6+CLB; n=9). Exercise was performed five times per week. Reduced weight bearing for 21 days was achieved through a novel harness suspension system. Treadmill velocity (12-20 m/min) and daily run time duration (32-51 min) increased incrementally throughout the study. Bone geometry and volumetric bone mineral density (vBMD) at proximal metaphysis and mid-diaphysis tibia were assessed by in vivo peripheral quantitative computed tomography (pQCT) on days 0 and 21 and standard dynamic histomorphometry was performed on undemineralized sections of the mid-diaphysis after tissue harvest. G/6 caused a significant decrease (P<0.001) in proximal tibia metaphysis total vBMD (-9.6%). These reductions of tibia metaphyseal vBMD in G/6 mice were mitigated in both G/6+RUN and G/6+CLB groups (P<0.05). After 21 days of G/6, we saw an absolute increase in tibia mid-diaphysis vBMD and in distal metaphysis femur vBMD in both G/6+RUN and G/6+CLB mice (P<0.05). Substantial increases in endocortical and periosteal mineralizing surface (MS/BS) at mid-diaphysis tibia in G/6+CLB demonstrate that

  18. Conference scene: Summary of the 6th Conference of the Romanian Association of Medical Laboratories with international participation.

    PubMed

    Carasevici, Eugen

    2011-10-01

    The Romanian Association of Medical Laboratories (RAML) conferences have acquired a reputation for standing out as the most prominent and efficient meetings in the national community of laboratory medicine, being a landmark of the development in this field in Romania and an active affiliation to international forums. This year, the conference setting was Piatra Neamt, in the northeast part of Romania, which produced a friendly and stimulating professional environment. As in previous years, leading experts in the fields of laboratory medicine attended the event. This year, we enjoyed the opportunity to have such distinguished guests as the members of the executive board of International Federation of Clinical Chemistry and Laboratory Medicine (IFCC); Graham Beastall, IFCC President; Päivi Hannele Laitinen, IFCC secretary; and Grazyna Sypniewska, IFCC Communication and Publication Division, and editor of the electronic journal of the IFCC. As usual, the conference program included all aspects of clinical laboratory activity, with a special focus on technology development, instrumentation and laboratory management. Fully aware of the fact that the complexity and depth of laboratory practice have undergone an impressive and rapid evolution, the specific goals of the event were to increase knowledge in the fundamentals of new molecular investigation, areas which show the tendency to become routine in our daily activity. In addition, laboratory management and the place of medical laboratories in the process of translational medicine were subjects of focus. The 6th Conference of the Romanian Association of Medical Laboratories was held from Wednesday 1st to Saturday 4th of June 2011. A total of 273 participants from all local branches of the Association attended. The scientific program included seven plenary sessions where 22 lectures and 18 short communications were delivered, and three poster sessions with 44 poster presentations. Session topics covered issues of

  19. Conference scene: Summary of the 6th Conference of the Romanian Association of Medical Laboratories with international participation.

    PubMed

    Carasevici, Eugen

    2011-10-01

    The Romanian Association of Medical Laboratories (RAML) conferences have acquired a reputation for standing out as the most prominent and efficient meetings in the national community of laboratory medicine, being a landmark of the development in this field in Romania and an active affiliation to international forums. This year, the conference setting was Piatra Neamt, in the northeast part of Romania, which produced a friendly and stimulating professional environment. As in previous years, leading experts in the fields of laboratory medicine attended the event. This year, we enjoyed the opportunity to have such distinguished guests as the members of the executive board of International Federation of Clinical Chemistry and Laboratory Medicine (IFCC); Graham Beastall, IFCC President; Päivi Hannele Laitinen, IFCC secretary; and Grazyna Sypniewska, IFCC Communication and Publication Division, and editor of the electronic journal of the IFCC. As usual, the conference program included all aspects of clinical laboratory activity, with a special focus on technology development, instrumentation and laboratory management. Fully aware of the fact that the complexity and depth of laboratory practice have undergone an impressive and rapid evolution, the specific goals of the event were to increase knowledge in the fundamentals of new molecular investigation, areas which show the tendency to become routine in our daily activity. In addition, laboratory management and the place of medical laboratories in the process of translational medicine were subjects of focus. The 6th Conference of the Romanian Association of Medical Laboratories was held from Wednesday 1st to Saturday 4th of June 2011. A total of 273 participants from all local branches of the Association attended. The scientific program included seven plenary sessions where 22 lectures and 18 short communications were delivered, and three poster sessions with 44 poster presentations. Session topics covered issues of

  20. Determination of 240Pu/239Pu atom ratio in seawaters from the East China Sea.

    PubMed

    Yamada, Masatoshi; Zheng, Jian

    2011-07-01

    The (240)Pu/(239)Pu atom ratios in seawater samples on the East China Sea continental shelf were measured. These ratios for surface and bottom waters had no significant difference. They were significantly higher than the average global fallout ratio of 0.18. It was proposed that the oceanic currents are accounted for delivery of close-in Pu from the Pacific Proving Grounds (PPG) to the studied areas. The contribution of the PPG close-in fallout was calculated to be 40 % on average. The (240)Pu/(239)Pu atom ratios should provide useful background data before the expected expansion of nuclear power capacity in East and South Asian countries and for distinguishing future sources of Pu.

  1. Resonant Photoemission in f Electron Systems: Pu& Gd

    SciTech Connect

    Tobin, J G; Chung, B W; Schulze, R K; Terry, J; Farr, J D; Shuh, D K; Heinzelman, K; Rotenberg, E; Waddill, G D; van der Laan, G

    2003-03-07

    Resonant photoemission in the Pu5f and Pu6p states is compared to that in the Gd4f and Gd5p states. Spectral simulations, based upon and atomic model with angular momentum coupling, are compared to the Gd and Pu results. Additional spectroscopic measurements of Pu, including core level photoemission and x-ray absorption are also presented.

  2. SB6.0: The 6th International meeting on Synthetic Biology, July 9-11, 2013

    SciTech Connect

    Kahl, Linda J.

    2015-04-23

    The Synthetic Biology conference series (SBx.0) is the preeminent academic meeting in synthetic biology. Organized by the BioBricks Foundation, the SBx.0 conference series brings together leading researchers, students, industry executives, and policy makers from around the world to share, consider, debate, and plan efforts to make biology easier to engineer. Historically held every two years, the SBx.0 conferences are held in alternating locations in the United States, Europe, and Asia to encourage global participation and collaboration so that the ramifications of synthetic biology research and development are most likely to be safe ethical, and beneficial. On 9-11 July 2013, the 6th installment of the synthetic biology conference series (SB6.0) was held on the campus of Imperial College London (http://sb6.biobricks.org). The SB6.0 conference was attended by over 700 people, and many more were able to participate via video digital conference (http://sb6.biobricks.org/digital-conference/). Over the course of three days, the SB6.0 conference agenda included plenary sessions, workshops, and poster presentations covering topics ranging from the infrastructure needs arising when “Systematic Engineering Meets Biological Complexity” and design-led considerations for “Connecting People and Technologies” to discussions on “Engineering Biology for New Materials,” “Assessing Risk and Managing Biocontainment,” and “New Directions for Energy and Sustainability.” The $10,150 grant awarded by the U.S. Department of Energy (DE-SC0010233) to the BioBricks Foundation was used to provide partial reimbursement for the travel expenses of leading researchers from the United States to speak at the SB6.0 conference. A total of $9,450 was used to reimburse U.S. speakers for actual expenses related to the SB6.0 conference, including airfare (economy or coach only), ground transportation, hotel, and registration fees. In addition, $700 of the grant was used to offset

  3. Future perspectives in melanoma research: meeting report from the "Melanoma Bridge": Napoli, December 3rd-6th 2014.

    PubMed

    Ascierto, Paolo A; Atkins, Michael; Bifulco, Carlo; Botti, Gerardo; Cochran, Alistair; Davies, Michael; Demaria, Sandra; Dummer, Reinhard; Ferrone, Soldano; Formenti, Silvia; Gajewski, Thomas F; Garbe, Claus; Khleif, Samir; Kiessling, Rolf; Lo, Roger; Lorigan, Paul; Arthur, Grant Mc; Masucci, Giuseppe; Melero, Ignacio; Mihm, Martin; Palmieri, Giuseppe; Parmiani, Giorgio; Puzanov, Igor; Romero, Pedro; Schilling, Bastian; Seliger, Barbara; Stroncek, David; Taube, Janis; Tomei, Sara; Zarour, Hassane M; Testori, Alessandro; Wang, Ena; Galon, Jérôme; Ciliberto, Gennaro; Mozzillo, Nicola; Marincola, Francesco M; Thurin, Magdalena

    2015-11-30

    The fourth "Melanoma Bridge Meeting" took place in Naples, December 3-6th, 2014. The four topics discussed at this meeting were: Molecular and Immunological Advances, Combination Therapies, News in Immunotherapy, and Tumor Microenvironment and Biomarkers. Until recently systemic therapy for metastatic melanoma patients was ineffective, but recent advances in tumor biology and immunology have led to the development of new targeted and immunotherapeutic agents that prolong progression-free survival (PFS) and overall survival (OS). New therapies, such as mitogen-activated protein kinase (MAPK) pathway inhibitors as well as other signaling pathway inhibitors, are being tested in patients with metastatic melanoma either as monotherapy or in combination, and all have yielded promising results. These include inhibitors of receptor tyrosine kinases (BRAF, MEK, and VEGFR), the phosphatidylinositol 3 kinase (PI3K) pathway [PI3K, AKT, mammalian target of rapamycin (mTOR)], activators of apoptotic pathway, and the cell cycle inhibitors (CDK4/6). Various locoregional interventions including radiotherapy and surgery are still valid approaches in treatment of advanced melanoma that can be integrated with novel therapies. Intrinsic, adaptive and acquired resistance occur with targeted therapy such as BRAF inhibitors, where most responses are short-lived. Given that the reactivation of the MAPK pathway through several distinct mechanisms is responsible for the majority of acquired resistance, it is logical to combine BRAF inhibitors with inhibitors of targets downstream in the MAPK pathway. For example, combination of BRAF/MEK inhibitors (e.g., dabrafenib/trametinib) have been demonstrated to improve survival compared to monotherapy. Application of novel technologies such sequencing have proven useful as a tool for identification of MAPK pathway-alternative resistance mechanism and designing other combinatorial therapies such as those between BRAF and AKT inhibitors. Improved

  4. Future perspectives in melanoma research: meeting report from the "Melanoma Bridge": Napoli, December 3rd-6th 2014.

    PubMed

    Ascierto, Paolo A; Atkins, Michael; Bifulco, Carlo; Botti, Gerardo; Cochran, Alistair; Davies, Michael; Demaria, Sandra; Dummer, Reinhard; Ferrone, Soldano; Formenti, Silvia; Gajewski, Thomas F; Garbe, Claus; Khleif, Samir; Kiessling, Rolf; Lo, Roger; Lorigan, Paul; Arthur, Grant Mc; Masucci, Giuseppe; Melero, Ignacio; Mihm, Martin; Palmieri, Giuseppe; Parmiani, Giorgio; Puzanov, Igor; Romero, Pedro; Schilling, Bastian; Seliger, Barbara; Stroncek, David; Taube, Janis; Tomei, Sara; Zarour, Hassane M; Testori, Alessandro; Wang, Ena; Galon, Jérôme; Ciliberto, Gennaro; Mozzillo, Nicola; Marincola, Francesco M; Thurin, Magdalena

    2015-01-01

    The fourth "Melanoma Bridge Meeting" took place in Naples, December 3-6th, 2014. The four topics discussed at this meeting were: Molecular and Immunological Advances, Combination Therapies, News in Immunotherapy, and Tumor Microenvironment and Biomarkers. Until recently systemic therapy for metastatic melanoma patients was ineffective, but recent advances in tumor biology and immunology have led to the development of new targeted and immunotherapeutic agents that prolong progression-free survival (PFS) and overall survival (OS). New therapies, such as mitogen-activated protein kinase (MAPK) pathway inhibitors as well as other signaling pathway inhibitors, are being tested in patients with metastatic melanoma either as monotherapy or in combination, and all have yielded promising results. These include inhibitors of receptor tyrosine kinases (BRAF, MEK, and VEGFR), the phosphatidylinositol 3 kinase (PI3K) pathway [PI3K, AKT, mammalian target of rapamycin (mTOR)], activators of apoptotic pathway, and the cell cycle inhibitors (CDK4/6). Various locoregional interventions including radiotherapy and surgery are still valid approaches in treatment of advanced melanoma that can be integrated with novel therapies. Intrinsic, adaptive and acquired resistance occur with targeted therapy such as BRAF inhibitors, where most responses are short-lived. Given that the reactivation of the MAPK pathway through several distinct mechanisms is responsible for the majority of acquired resistance, it is logical to combine BRAF inhibitors with inhibitors of targets downstream in the MAPK pathway. For example, combination of BRAF/MEK inhibitors (e.g., dabrafenib/trametinib) have been demonstrated to improve survival compared to monotherapy. Application of novel technologies such sequencing have proven useful as a tool for identification of MAPK pathway-alternative resistance mechanism and designing other combinatorial therapies such as those between BRAF and AKT inhibitors. Improved

  5. [Pu(IV) behavior in the serum].

    PubMed

    Surova, Z I

    1984-01-01

    This paper presents the results of studies of the hydrolysis and polymerization of Pu(IV) in blood serum. With nitrite Pu(IV) solutions incubated with blood serum 20-34% of the nuclide were precipitated as hydroxide and 11-36% converted into polymeric forms bound by high molecular weight proteins. For citrate solutions, these values were 3.8 and 3.0%, respectively. PMID:6505160

  6. The Spectroscopic Signature of Aging in (delta)-Pu(Ga)

    SciTech Connect

    Tobin, J G; Yu, S; Chung, B W

    2009-04-29

    The electronic structure of Pu is briefly discussed, with emphasis upon Aging effects. Photoelectron Spectroscopy and X-ray Absorption Spectroscopy have contributed greatly to our improved understanding of Pu electronic structure. (See Figure 1.) From these and related measurements, the following has been determined: (1) The Pu 5f spin-orbit splitting is large; (2) The number of Pu5f electrons is 5; and (3) The Pu 5f spin-orbit splitting effect dominates 5f itineracy.

  7. Archeomagnetic Intensity Variations During the 6th Millennium BC in the Middle East: New Data from Yarim Tepe II (Northern Iraq)

    NASA Astrophysics Data System (ADS)

    Akimova, S.; Gallet, Y.; Amirov, S.

    2015-12-01

    During the seventies, Soviet archeologists conducted in Northern Iraq excavations of several ancient settlements dated from the Pottery Late Neolithic period (7th and 6th millennia BC). A very large collection of artifacts unearthed from these sites, in particular several thousands of well-documented pottery fragments, is now stored at the Archeological Institute in Moscow. We collected a time-sequential series of groups of potsherds from the multilayered settlement called Yarim Tepe II dated to the Halaf period (6th millennium BC). Each group comprises a minimum of 3 potsherds (up to 10) found within a same archeological layer, typically a thickness of about 20 cm. Altogether, the fragment groups encompass the entire 7-m thick stratigraphic sequence of Yarim Tepe II. We will present our first archeointensity results obtained using the experimental protocol developed for the Triaxe magnetometer, taking into account the effects of both the thermoremanent magnetization (TRM) anisotropy and the cooling rate dependence on TRM acquisition. The new data help to better constrain the geomagnetic field intensity variations in the Middle East during the 6th millennium BC. Thanks to the comparison with other datasets from Bulgaria and Syria, the new archeointensity results provide evidence for the occurrence of very rapid geomagnetic field intensity variations around 5500 BC.

  8. Chemical potential of oxygen in (U, Pu) mixed oxide with Pu/(U+Pu) = 0.46

    NASA Astrophysics Data System (ADS)

    Dawar, Rimpi; Chandramouli, V.; Anthonysamy, S.

    2016-05-01

    Chemical potential of oxygen in (U,Pu) mixed oxide with Pu/(U + Pu) = 0.46 was measured for the first time using H2/H2O gas equilibration combined with solid electrolyte EMF technique at 1073, 1273 and 1473 K covering an oxygen potential range of -525 to -325 kJ mol-1. The effect of oxygen potential on the oxygen to metal ratio was determined. Increase in oxygen potential increases the O/M. In this study the minimum O/M obtained was 1.985 below which reduction was not possible. Partial molar enthalpy ΔHbar O2 and entropy ΔSbar O2 of oxygen were calculated from the oxygen potential data. The values of -752.36 kJ mol-1 and 0.25 kJ mol-1 were obtained for ΔHbar O2 and ΔSbar O2 respectively.

  9. Prompt fission γ -ray spectrum characteristics from 240Pu(sf ) and 242Pu(sf )

    NASA Astrophysics Data System (ADS)

    Oberstedt, S.; Oberstedt, A.; Gatera, A.; Göök, A.; Hambsch, F.-J.; Moens, A.; Sibbens, G.; Vanleeuw, D.; Vidali, M.

    2016-05-01

    In this paper we present first results for prompt fission γ -ray spectra (PFGS) characteristics from the spontaneous fission (sf) of 240Pu and 242Pu. For 242Pu(sf ) we obtained, after proper unfolding of the detector response, an average energy per photon ɛ¯γ=(0.843 ±0.012 ) MeV, an average multiplicity M¯γ=(6.72 ±0.07 ) , and an average total γ -ray energy release per fission E¯γ ,tot = (5.66 ± 0.06) MeV. The 240Pu(sf ) emission spectrum was obtained by applying a so-called detector-response transformation function determined from the 242Pu spectrum measured in exactly the same geometry. The results are an average energy per photon ɛ¯γ=(0.80 ±0.07 ) MeV, the average multiplicity M¯γ = (8.2 ± 0.4), and an average total γ -ray energy release per fission E¯γ ,tot = (6.6 ± 0.5) MeV. The PFGS characteristics for 242Pu(sf ) are in very good agreement with those from thermal-neutron-induced fission on 241Pu and scales well with the corresponding prompt neutron multiplicity. Our results in the case of 240Pu(sf ), although drawn from a limited number of events, show a significantly enhanced average multiplicity and average total energy, but may be understood from a different fragment yield distribution in 240Pu(sf ) compared to that of 242Pu(sf ).

  10. Redefining design criteria for Pu-238 gloveboxes

    SciTech Connect

    Acosta, S.V.

    1998-12-31

    Enclosures for confinement of special nuclear materials (SNM) have evolved into the design of gloveboxes. During the early stages of glovebox technology, established practices and process operation requirements defined design criteria. Proven boxes that performed and met or exceeded process requirements in one group or area, often could not be duplicated in other areas or processes, and till achieve the same success. Changes in materials, fabrication and installation methods often only met immediate design criteria. Standardization of design criteria took a big step during creation of ``Special-Nuclear Materials R and D Laboratory Project, Glovebox standards``. The standards defined design criteria for every type of process equipment in its most general form. Los Alamos National Laboratory (LANL) then and now has had great success with Pu-238 processing. However with ever changing Environment Safety and Health (ES and H) requirements and Ta-55 Facility Configuration Management, current design criteria are forced to explore alternative methods of glovebox design fabrication and installation. Pu-238 fuel processing operations in the Power Source Technologies Group have pushed the limitations of current design criteria. More than half of Pu-238 gloveboxes are being retrofitted or replaced to perform the specific fuel process operations. Pu-238 glovebox design criteria are headed toward process designed single use glovebox and supporting line gloveboxes. Gloveboxes that will house equipment and processes will support TA-55 Pu-238 fuel processing needs into the next century and extend glovebox expected design life.

  11. 239+240Pu concentration and isotope ratio (240Pu/239Pu) in aerosols during high dust (Yellow Sand) period, Korea.

    PubMed

    Choi, Man Sik; Lee, Dong-Soo; Choi, Jae-Cheon; Cha, Hyun-Ju; Yi, Hee-Il

    2006-10-15

    Concentration and isotope ratio of Pu were analyzed for aerosols collected at Anmyeondo located in the western coast of Korea using multiple collector inductively coupled plasma mass spectrometer equipped with desolvated micro-concentric nebulizer. Aerosols were collected from June 2001 to April 2002 using high volume air sampler. The samples consist of high dust samples (Yellow Sand), and also low dust samples; maximum Al concentration was 74.2 microg/m(3) and minimum was 0.17 microg/m(3). Pu was concentrated using 0.1 ml TEVA resin columns after conc. HNO(3) extraction. Isotope dilution using (242)Pu spike and mass bias correction using (233)U and (236)U mixed solution enabled the quantification of Pu and measurement of isotope ratio simultaneously. The contribution of (238)U from both spikes and samples was minimized by careful chemical separation and optimization of spike concentration. The (238)U(1)H and tail contribution on (239)Pu peak were about 0.75 x 10(-5) and 1 x 10(-5) of (238)U intensity, respectively, and they were corrected from (239)Pu using externally determined ((238)U(1)H + tailing)/(238)U ratio and (238)U measurement during acquisition. The detection limits of this analytical procedure were 0.61 fg/ml and 0.56 fg/ml for (239)Pu and (240)Pu, respectively (4 nBq/m(3) and 12 nBq/m(3) for (239)Pu and (240)Pu, respectively). The precision of isotope ratio measurement was better than 2% for larger quantity than 20 fg of (239)Pu. In spring, maximum concentration of 0.580 microBq/m(3) for (239)Pu and 0.404 microBq/m(3) for (240)Pu was observed when Al concentration was maximum, so called as Yellow Sand event. Pu concentrations in aerosols are well correlated with Al, a tracer of soil dust. The ratios of Pu/Al were 0.0082 (microBq/microg) and 0.0055 (microBq/microg) for (239)Pu/Al and (240)Pu/Al, respectively. Isotope ratios of Pu ((240)Pu/(239)Pu) in Yellow Sand samples show 0.191+/-0.014 close to those of global fallout. These facts indicate that

  12. Knockdown of PU.1 AS lncRNA inhibits adipogenesis through enhancing PU.1 mRNA translation.

    PubMed

    Pang, Wei-Jun; Lin, Li-Gen; Xiong, Yan; Wei, Ning; Wang, Yu; Shen, Qing-Wu; Yang, Gong-She

    2013-11-01

    PU.1 is an Ets family transcription factor involved in the myelo-lymphoid differentiation. We have previously demonstrated that PU.1 is also expressed in the adipocyte lineage. However, the expression levels of PU.1 mRNA and protein in preadipocytes do not match the levels in mature adipocytes. PU.1 mRNA level is higher in preadipocytes, whereas its protein is expressed in the adipocytes but not in the preadipocytes. The underlying mechanism remains elusive. Here, we find that miR-155 knockdown or overexpression has no effect on the levels of PU.1 mRNA and protein in preadipocytes or adipocytes. MiR-155 regulates adipogenesis not through PU.1, but via C/EBPβ which is another target of miR-155. We also checked the expression levels of PU.1 mRNA and antisense long non-coding RNA (AS lncRNA). Interestingly, compared with the level of PU.1 mRNA, the level of PU.1 AS lncRNA is much higher in preadipocytes, whereas it is opposite in the adipocytes. We further discover that PU.1 AS lncRNA binds to its mRNA forming an mRNA/AS lncRNA compound. The knockdown of PU.1 AS by siRNA inhibits adipogenesis and promotes PU.1 protein expression in both preadipocytes and adipocytes. Furthermore, the repression of PU.1 AS decreases the expression and secretion of adiponectin. We also find that the effect of retroviral-mediated PU.1 AS knockdown on adipogenesis is consistent with that of PU.1 AS knockdown by siRNA. Taken together, our results suggest that PU.1 AS lncRNA promotes adipogenesis through preventing PU.1 mRNA translation via binding to PU.1 mRNA to form mRNA/AS lncRNA duplex in preadipocytes.

  13. Oxidation behaviour of plutonium rich (U, Pu)C and (U, Pu)O2

    NASA Astrophysics Data System (ADS)

    Sali, S. K.; Kulkarni, N. K.; Phatak, Rohan; Agarwal, Renu

    2016-10-01

    Oxidation behaviour of (U0.3Pu0.7)C1.06 was investigated in air by heating samples up to 1073 K and 1273 K. Thermogravimetry (TG) of the samples and X-ray powder diffraction (XRD) of the intermediate products were used to understand the phenomenon taking place during this process. Theoretical calculations were carried out to understand the multiple phase changes taking place during oxidation of carbide. Theoretical results were validated by XRD analysis of the products obtained at different stages of oxidation. The final oxidized products were found to be a single FCC phase with O/M = 2.15 (M = U + Pu). Oxidation kinetic studies of (U0.3Pu0.7)O2 and (U0.47Pu0.53)O2 were carried out in dry air, using thermogravimetry, under non-isothermal conditions. The activation energy of oxidation was found to be 49 and 70 kJ/mol, respectively. Lattice parameter dependence on Pu/M and O/M of plutonium rich mixed oxide (MOX) was established using combined results of XRD and TG analysis of (U0.3Pu0.7)O2+x and (U0.47Pu0.53)O2+x.

  14. Isochronal Annealing Studies in Pu and Pu Alloys Using Magnetic Susceptibility

    SciTech Connect

    McCall, S. K.; Fluss, M. J.; Chung, B. W.; McElfresh, M. W.; Chapline, G.F.; Jackson, D. D.; Haire, Richard {Dick} G

    2007-01-01

    The isochronal annealing of the low temperature accumulated damage from the radioactive decay of plutonium in {alpha}-Pu, {delta}-Pu{sub 1-x}Ga{sub x} (x = 0.043) and {delta}-Pu{sub 1-x}Am{sub x} (x = 0.224) was characterized using magnetic susceptibility. In each specimen, thermal annealing, as tracked by magnetic susceptibility, only commenced when T > 33 K and the magnetic susceptibility changes due to defects were fully annealed at T not, vert, similar 300 K. The {alpha}-Pu magnetic susceptibility isochronal annealing data is similar to earlier measurements of resistivity characterized isochronal annealing. However, the {delta}-Pu{sub 1-x}Ga{sub x} (x = 0.043) magnetic susceptibility isochronal annealing data, when compared with similar resistivity data, indicates that for this alloy magnetic susceptibility studies are more sensitive to vacancies than to the interstitials accumulated at low temperatures. The Pu{sub 1-x}Am{sub x} (x = 0.224) alloy shows a remarkable change in properties, over a limited temperature range beginning where interstitial defects are first mobile, and characterized by an induced effective moment of order 1.1 {mu}{sub B}/Pu. This transient behavior may be evidence for a disorder driven low temperature phase transition, perhaps indicative of a compositional and structural proximity to a state possessing significant magnetic moments.

  15. $sup 238$Pu fuel form activities

    SciTech Connect

    Not Available

    1987-06-01

    This report for STYPu Fuel Form Activities has one main section: SRP-PuFF Facility. The SRL portion of this program has been completed. The program status, budget information, and milestone schedules are discussed. The SRP portion of this report summarizes production of STYPuO2 fuel forms for use in radioisotopic thermoelectric generators (RTG's) in the Plutonium Fuel Form (Puff) Facility at the Savannah River Plant. The PuFF Facility has been placed in a production readiness mode of operation pending funding of additional heat source programs.

  16. Plutonium diffusion in advanced fuels (U,Pu)(C,O) and (U,Pu)(C,N)

    SciTech Connect

    Bradbury, M.H.; Matzke, H.

    1983-07-01

    The self-diffusion of /sup 238/Pu was measured in an oxicarbide (U,Pu)(C,O) and a carbonitride (U,Pu) (C,N). The activation enthalpies were 447 and 347 kJ mol/sup -1/, respectively. The carbonitrides were confirmed to fall into three classes: carbide-like compositions with less than 30% nitrogen in the metalloid lattice, nitride-like composition with more than 70% nitrogen and with reduced atomic mobilities, and carbonitrides with about 50% nitrogen showing an intermediate behavior. The oxicarbide showed diffusion coefficients slightly larger than those of pure carbides.

  17. 6th Annual Symposium on Self-Monitoring of Blood Glucose (SMBG) Applications and Beyond, April 25–27, 2013, Riga, Latvia

    PubMed Central

    Schlaeger, Christof; Hinzmann, Rolf

    2013-01-01

    Abstract International experts in the fields of diabetes, diabetes technology, endocrinology, and pediatrics gathered for the 6th Annual Symposium on Self-Monitoring of Blood Glucose (SMBG) Applications and beyond. The aim of this meeting was to continue setting up a global network of experts in this field and provide an international platform for exchange of ideas to improve life for people with diabetes. The 2013 meeting comprised a comprehensive scientific program, parallel interactive workshops, and two keynote lectures. All these discussions were intended to help identify gaps and areas where further scientific work and clinical studies are warranted. PMID:24074038

  18. Pu-238 fuel form activities, January 1-31, 1985

    SciTech Connect

    Not Available

    1985-07-01

    This monthly report summarizes production of /sup 238/PuO/sub 2/ fuel forms for use in radioisotopic thermoelectric generators (RTG's) in the Plutonium Fuel Form (PuFF) Facility at the Savannah River Plant.

  19. Experimental Benchmarking of Pu Electronic Structure

    SciTech Connect

    Tobin, J G; Moore, K T; Chung, B W; Wall, M A; Schwartz, A J; Ebbinghaus, B B; Butterfield, M T; Teslich, Jr., N E; Bliss, R A; Morton, S A; Yu, S W; Komesu, T; Waddill, G D; der Laan, G v; Kutepov, A L

    2005-10-13

    The standard method to determine the band structure of a condensed phase material is to (1) obtain a single crystal with a well defined surface and (2) map the bands with angle resolved photoelectron spectroscopy (occupied or valence bands) and inverse photoelectron spectroscopy (unoccupied or conduction bands). Unfortunately, in the case of Pu, the single crystals of Pu are either nonexistent, very small and/or having poorly defined surfaces. Furthermore, effects such as electron correlation and a large spin-orbit splitting in the 5f states have further complicated the situation. Thus, we have embarked upon the utilization of unorthodox electron spectroscopies, to circumvent the problems caused by the absence of large single crystals of Pu with well-defined surfaces. Our approach includes the techniques of resonant photoelectron spectroscopy [1], x-ray absorption spectroscopy [1,2,3,4], electron energy loss spectroscopy [2,3,4], Fano Effect measurements [5], and Bremstrahlung Isochromat Spectroscopy [6], including the utilization of micro-focused beams to probe single-crystallite regions of polycrystalline Pu samples. [2,3,6

  20. Experimental Benchmarking of Pu Electronic Structure

    SciTech Connect

    Tobin, J.G.; Moore, K.T.; Chung, B.W.; Wall, M.A.; Schwartz, A.J.; Ebbinghaus, B.B.; Butterfield, M.T.; Teslich, Jr., N.E.; Bliss, R.A.; Morton, S.A.; Yu, S.W.; Komesu, T.; Waddill, G.D.; van der Laan, G.; Kutepov, A.L.

    2008-10-30

    The standard method to determine the band structure of a condensed phase material is to (1) obtain a single crystal with a well defined surface and (2) map the bands with angle resolved photoelectron spectroscopy (occupied or valence bands) and inverse photoelectron spectroscopy (unoccupied or conduction bands). Unfortunately, in the case of Pu, the single crystals of Pu are either nonexistent, very small and/or having poorly defined surfaces. Furthermore, effects such as electron correlation and a large spin-orbit splitting in the 5f states have further complicated the situation. Thus, we have embarked upon the utilization of unorthodox electron spectroscopies, to circumvent the problems caused by the absence of large single crystals of Pu with well-defined surfaces. Our approach includes the techniques of resonant photoelectron spectroscopy, x-ray absorption spectroscopy, electron energy loss spectroscopy, Fano Effect measurements, and Bremstrahlung Isochromat Spectroscopy, including the utilization of micro-focused beams to probe single-crystallite regions of polycrystalline Pu samples.

  1. Pu-238 fuel form activities, June 1-30, 1980

    SciTech Connect

    Not Available

    1980-07-18

    This monthly report for Pu-238 Fuel Form Activities has two main sections: SRP-PuFF Pu-238 Fuel Form Production Processes and SRL Pu-238 Fuel Form Research and Development. The program status, budget information, and milestone information are discussed in each main section. The Work Breakdown Structures (WBS) for this program is outlined. Only one monthly report per year is processed for EDB.

  2. The 239 Pu(n,2n)238Pu cross section: preliminary calculations

    SciTech Connect

    Chen, H; Reffo, G; Ross, M A; White, R M

    1999-03-12

    The primary motivation for the present work is to provide theoretical values for the ratio of the partial 239Pu(n,2nx{gamma})238Pu to total 239 Pu(n,2n)238Pu cross section for several discrete gamma transitions. Results and conclusions of preliminary calculations from threshold to 20 MeV are presented. Calculations are based on theoretical models with parameters obtained from the literature or from our ad hoc systematics. Optical model cross sections and transmission coefficients were determined using the coupled-channels method. The calculations included a preequilibrium component followed by multiple particle and gamma-ray emissions. Fission competition was included at all stages of de-excitation. Suggestions for further verifications and possible improvements are provided.

  3. Investigation of single crystal zircon, (Zr,Pu)SiO4 doped with Pu

    NASA Astrophysics Data System (ADS)

    Hanchar, J. M.; Burakov, B. E.; Anderson, E. B.; Zamoryanskaya, M. V.

    2003-04-01

    Zircon-based ceramics are under consideration as durable waste forms for immobilization of weapons grade plutonium and other actinide elements. Samples of polycrystalline zircon doped with 238Pu and 239Pu have been obtained in previous studies. These materials, however, are difficult to use for precise measurement of the leach-rate of Pu, and to accurately determine the level of Pu doping that can be attained in zircon, (Zr,Pu)SiO_4. Single crystals of 238Pu doped zircon (ranging from 0.3 to 3.5 mm in size) were successfully grown for the first time ever using a Li-Mo flux synthesis method. The incorporation of Pu ranged from 1.9 to 4.7 wt. % el. (with approximately 81 wt.% of 238Pu isotope) based on electron microprobe analysis. The zircon crystals were pinkish-brown when they were crystallized, and then over a period of five months changed to a brown color. After fourteen months the crystals turned to a brown-gray color. The zircon crystals glow in the dark probably from alpha particle induced luminescence. The intensity of the cathodoluminescence (CL) emission in the Pu doped crystals is correlated with the Pu content, and the CL emission showed no change 141 days after the initial CL measurements were made. Single crystal X-ray diffraction results obtained 141 days after synthesis indicate unit cell parameters (in angstroms): a = 6.6267(15), c = 5.9992(10) and a cell volume of 263.41(10). When the zircon crystals were grown, they were free of cracks. Over the course of five months cracks appeared throughout the crystals, and after fourteen months the cracks became much more abundant. The zircon crystals were transparent upon crystallization, and even with numerous cracks throughout the crystals remain transparent. Radiation damage calculations indicate that after only a short period of time, six months, these zircon crystals had already accumulated significant alpha-induced radiation damage (˜2.5 x1014 alpha-decay events per milligram). After five years they

  4. Spectroscopic Signature of Aging in (delta)-Pu(Ga)

    SciTech Connect

    Chung, B W; Schwartz, A J; Ebbinghaus, B B; Fluss, M J; Haslam, J J; Blobaum, K M; Tobin, J G

    2005-04-15

    Resonant Photoemission, a variant of Photoelectron Spectroscopy, has been demonstrated to have sensitivity to aging of Pu samples. The spectroscopic results are correlated with resistivity measurements and are shown to be the fingerprint of mesoscopic or nanoscale internal damage in the Pu physical structure. This means that a spectroscopic signature of internal damage due to aging in Pu has been established.

  5. Smoking practices, risk perception of smoking, and environmental tobacco smoke exposure among 6th-grade students in Ciudad Juárez, Mexico.

    PubMed

    Bird, Yelena; Moraros, John; Olsen, Larry K; Forster-Cox, Sue; Staines-Orozco, Hugo; Buckingham, Robert W

    2007-02-01

    This study assessed the smoking practices, risk perception of smoking, and environmental tobacco smoke (ETS) exposure among adolescents in Ciudad Juárez, Mexico. We used a cross-sectional method to examine the smoking practices, risk perception of smoking, and ETS exposure of 6th-grade students (N=506), aged 11-13 years, attending six randomly selected middle schools. Schools were classified by school setting (i.e., public vs. private) and socioeconomic status (SES; i.e., low, middle, or high). The results indicated that 6th-grade students attending a public, low-SES school setting in Ciudad Juárez not only exhibited significantly higher rates of ETS exposure at home and in public places (p<.01) but also were more likely to have tried smoking (p<.01) and to be current smokers (p<.01), and were less likely to support a ban on smoking in public places (p<.01), compared with students who attended a private school or a public, middle- or high-SES school setting. These results provide further evidence that public health interventions to prevent initiation of smoking and to assist in smoking cessation among adolescents and to reduce their ETS exposure at home and in public need to target all school-aged students, especially those attending school in a low-SES settings.

  6. Metastatic lymph node ratio, 6th or 7th AJCC edition: witch is the best lymph node classification for esophageal cancer? Prognosis factor analysis in 487 patients

    PubMed Central

    CORAL, Roberto V.; BIGOLIN, André V.; CORAL, Roberto P.; HARTMANN, Antonio; DRANKA, Carolina; ROEHE, Adriana V.

    2015-01-01

    Background The esophageal cancer is one of the most common and aggressive worldwide. Recently, the AJCC changed the staging system, considering, among others, the important role of the lymph node metastasis on the prognosis. Aim To discuss the applicability of different forms of lymph node staging in a western surgical center. Methods Four hundred eighty seven patients with esophageal cancer were enrolled. Three staging systems were evaluated, the 6th and the 7th AJCC editions and the Lymph Node Metastatic Ratio. Results The majority of the cases were squamous cell carcinoma. The mean lymph node sample was eight. Considering the survival, there was no significant difference between the patients when they were classified by the 7th AJCC edition. Analysis of the Lymph Node Metastatic Ratio, just on the group of patients with 0 to 25%, has shown significant difference (p=0,01). The 6th AJCC edition shows the major significant difference between among the classifications evaluated. Conclusion In this specific population, the 7th AJCC edition for esophageal cancer was not able to find differences in survival when just the lymph node analysis was considered. PMID:26176242

  7. Downregulated Expression of Ly-6-ThB on Developing T Cells Marks CD4+CD8+ Subset Undergoing Selection in the Thymus

    PubMed Central

    Reese, Justin T.; Mehta, Hitesh; Chappell, Clay H.

    2001-01-01

    Interaction of TCRs on CD4+CD8+ immature T cell with MHC-peptide complexes on stromal cells is required for positive and negative selection in the thymus. Identification and characterization of a subpopulation of CD4+CD8+ thymocytes undergoing selection in the thymus will aid in understanding the mechanisms underlying lineage commitment and thymic selection. Herein, we describe the expression of Ly-6 ThB on developing thymocytes. The majority of CD4+CD8+ thymocytes express Ly-6 ThB at high levels. Its expression is downregulated in a subset of CD4+CD8+ thymocytes as well as in mature CD4+CD8- and CD4-CD8+ T cells. More importantly, interaction of TCR/coreceptor with the self-MHC-peptide contributes to the downregulation of ThB expression on developing thymocytes. These findings indicate that downregulation of ThB on CD4+CD8+ thymocytes identifies a unique subset (CD4+CD8+ThBneg–low) of thymocytes that has received the initial signals for thymic selection but have not yet downregulated the CD4 and CD8 cell surface expression. In addition, these results also indicate that a high frequency (Ÿ20–40%) of CD4+CD8+ immature thymocytes receive these initial signals during thymic selection. PMID:11589307

  8. Rabies vaccine standards: comparison of the 5th and 6th WHO international reference standards to the USDA veterinary reference standard.

    PubMed

    Hermann, J; Fry, A; Reising, M; Patterson, P; Siev, D; Gatewood, D

    2012-11-01

    Ensuring rabies vaccines are potent and effective is paramount in preventing transmission of this deadly disease and safeguarding public health. Efficacy of human and veterinary vaccines is ensured by evaluating relative potency estimates of the vaccine compared to a rabies reference standard using the National Institutes of Health (NIH) test. Reference vaccines are based on the International Standard for Rabies Vaccine provided by the World Health Organization (WHO). A comparison study was conducted to determine the relative potency of the 5th WHO, 6th WHO, and United States Department of Agriculture's (USDA) 08-14 reference standards using the NIH test. Results from the study demonstrate that the 6th WHO reference standard is approximately twice as potent as the 5th WHO reference when reconstituted to contain 1 IU per ml. Based on these results, the Center for Veterinary Biologics (CVB) doubled the reconstitution volume of USDA veterinary reference 08-14 from 13 ml to 26 ml, for an initial use dilution of 0.7 IU per ml for use by veterinary biologics manufacturers in the NIH test. This study emphasizes the importance of reference standard calibration for use in the National Institutes of Health test.

  9. Electronic structure of delta-Pu and PuCoGa[sub 3] from photoemission and the mixed level model

    SciTech Connect

    Joyce, J. J.; Wills, J. M.; Durakiewicz, T.; Butterfield, M. T.; Guziewicz, E.; Sarrao, John L.,; Arko, A. J.; Moore, D. P.; Morales, L. A.; Eriksson, O.

    2004-01-01

    The electronic structure of {delta}-phase Pu metal and the Pu-based superconductor PuCoGa{sub 5} is explored using photoelectron spectroscopy and a novel theoretical scheme. Excellent agreement between calculation and experiment defines a path forward for understanding electronic structure aspects of Pu-based materials. The photoemission results show two separate regions of 5f electron spectral intensity, one at the Fermi energy and another centered 1.2 eV below the Fermi level. A comparison is made between the photoemission data and five computational schemes for {delta}-Pu. The results for {delta}-Pu and PuCoGa{sub 5} indicate 5f electron behavior on the threshold between localized and itinerant and a broader framework for understanding the fundamental electronic properties of the Pu 5f levels in general within two configurations, one localized and one itinerant.

  10. Vertical distributions of radionuclides ((239+240)Pu, (240)Pu/(239)Pu, and (137)Cs) in sediment cores of Lake Bosten in Northwestern China.

    PubMed

    Liao, Haiqing; Bu, Wenting; Zheng, Jian; Wu, Fengchang; Yamada, Masatoshi

    2014-04-01

    Artificial radionuclides ((137)Cs, (239+240)Pu, (241)Pu, (241)Am) deposited in lacustrine sediments have been used for dating as well as radionuclide source identification. In the present work, we investigated the vertical distributions of (239+240)Pu and (137)Cs activities, (240)Pu/(239)Pu atom ratios, and (239+240)Pu/(137)Cs activity ratios in sediment cores collected from Lake Bosten, which is the lake closest to the Lop Nor Chinese Nuclear Weapon Test site in northwestern China. Uniformly high concentrations of (239+240)Pu and (137)Cs were found in the upper layers deposited since 1964 in the sediment cores, and these were controlled by the resuspension of soil containing radionuclides from the nearby land surface. As the Chinese nuclear tests varied remarkably in yield, the mixing of the tropospheric deposition from these tests and the stratospheric deposition of global fallout has led to a (240)Pu/(239)Pu atom ratio that is similar to that of global fallout and to a (239+240)Pu/(137)Cs activity ratio that is slightly higher than that of global fallout. However, a low (240)Pu/(239)Pu atom ratio of 0.080 and high (239+240)Pu/(137)Cs activity ratio of 0.087, significantly different from the global fallout values, were observed in one sediment core (07BS10-2), indicating the inhomogenous tropospheric deposition from the Chinese nuclear tests in Lake Bosten during 1967-1973. These results are important to understand the influence of the CNTs on the radionuclide contamination in Lake Bosten.

  11. Determination of (239)Pu, (240)Pu, (241)Pu and (242)Pu at femtogram and attogram levels - evidence for the migration of fallout plutonium in an ombrotrophic peat bog profile.

    PubMed

    Quinto, Francesca; Hrnecek, Erich; Krachler, Michael; Shotyk, William; Steier, Peter; Winkler, Stephan R

    2013-04-01

    The isotopic composition of plutonium ((239)Pu, (240)Pu, (241)Pu and (242)Pu) was investigated in a ∼0.5 m long peat core from an ombrotrophic bog (Black Forest, Germany) using clean room procedures and accelerator mass spectrometry (AMS). This sophisticated analytical approach was ultimately needed to detect reliably the Pu concentrations present in the peat samples at femtogram (fg) and attogram (ag) levels. The mean (240)Pu/(239)Pu isotopic ratio of 0.19 ± 0.02 (N = 32) in the peat layers, representing approximately the last 80 years, was in good agreement with the accepted value of 0.18 for the global fallout in the Northern Hemisphere. This finding is largely supported by the corresponding and rather constant (241)Pu/(239)Pu (0.0012 ± 0.0005) and (242)Pu/(239)Pu (0.004 ± 0.001) ratios. Since the Pu isotopic composition characteristic of the global fallout was also identified in peat samples pre-dating the period of atmospheric atom bomb testing (AD 1956-AD 1980), migration of Pu within the peat profile is clearly indicated. These results highlight, for the first time, the mobility of Pu in a peat bog with implications for the migration of Pu in other acidic, organic rich environments such as forest soils and other wetland types. These findings constitute a direct observation of the behaviour of Pu at fg and ag levels in the environment. The AMS measurements of Pu concentrations (referring to a corresponding activity of (240+239)Pu from 0.07 mBq g(-1) to 5 mBq g(-1)) essentially confirm our a priori estimates based on existing (241)Am and (137)Cs data in the investigated peat core and agree well with the global fallout levels from the literature. Exclusively employing the Pu isotope ratios established for the peat samples, the date of the Pu irradiation (AD 1956, correctable to AD 1964) was calculated and subsequently compared to the (210)Pb age of the peat layers; this comparison provided an additional hint that global fallout derived Pu is not fixed in

  12. Prediction of thermodynamic property of Pu-zircon and Pu-pyrochlore

    NASA Astrophysics Data System (ADS)

    Xu, Hulfang; Wang, Yifeng

    2000-07-01

    Due to its high durability, zircon is often present as a heavy mineral in natural environments and is the oldest mineral that has been dated on the earth. There are four zircon structure phases of M4+SiO4 occurring in nature: zircon (ZrSiO4), hafnon (HfSiO4), thorite (ThSiO4), and coffinite (USiO4). These phases may form solid solution. Recent interest in zircon minerals stems from the study of highly durable radioactive waste forms. Crystalline phases of M4+SiO4 with zircon structure have been proposed as a durable ceramic waste form for immobilizing actinides such as Pu, Np, and U. To predict the behavior of zircon-based waste forms in a geologic repository environment as well as to optimize the fabrication of those waste forms, the thermodynamic and kinetic properties for zircon mineral phases have to be determined. In this paper, we use a linear free energy relationship to predict the Gibbs free energies of formation of Pu-bearing phases (Xu et al., 1999). The calculated results show that the PuSiO4 phase with zircon structure is unstable with respect to oxides of PuO2 and quartz. However, the PuSiO4 phase will be stable with respect to oxides of PuO2 and silica glass at low temperature.

  13. Pu speciation in actual and simulated aged wastes

    SciTech Connect

    Lezama-pacheco, Juan S; Conradson, Steven D

    2008-01-01

    X-ray Absorption Fine Structure Spectroscopy (XAFS) at the Pu L{sub II/III} edge was used to determine the speciation of this element in (1) Hanford Z-9 Pu crib samples, (2) deteriorated waste resins from a chloride process ion-exchange purification line, and (3) the sediments from two Waste Isolation Pilot Plant Liter Scale simulant brine systems. The Pu speciation in all of these samples except one is within the range previously displayed by PuO{sub 2+x-2y}(OH){sub y}{center_dot}zH{sub 2}O compounds, which is expected based on the putative thermodynamic stability of this system for Pu equilibrated with excess H{sub 2}O and O{sub 2} under environmental conditions. The primary exception was a near neutral brine experiment that displayed evidence for partial substitution of the normal O-based ligands with Cl{sup -} and a concomitant expansion of the Pu-Pu distance relative to the much more highly ordered Pu near neighbor shell in PuO{sub 2}. However, although the Pu speciation was not necessarily unusual, the Pu chemistry identified via the history of these samples did exhibit unexpected patterns, the most significant of which may be that the presence of the Pu(V)-oxo species may decrease rather than increase the overall solubility of these compounds. Several additional aspects of the Pu speciation have also not been previously observed in laboratory-based samples. The molecular environmental chemistry of Pu is therefore likely to be more complicated than would be predicted based solely on the behavior of PuO{sub 2} under laboratory conditions.

  14. Biokinetics of sup 237 Pu citrate and nitrate in the rat: Implications for Pu studies in man

    SciTech Connect

    Talbot, R.J.; Knight, D.A.; Morgan, A. )

    1990-08-01

    Plutonium-237 decays mainly by electron capture with a half-life of 45 d. Alpha particles are emitted in only 5 x 10(-3)% of its disintegrations. This nuclide can now be produced with relatively small amounts of alpha-emitting contaminants so that, in principle, {sup 237}Pu can be used for studies of Pu biokinetics in man. However, because of its high specific activity, there was some doubt that its metabolism would be the same as that of the alpha- and beta-emitting isotopes of Pu normally encountered in the nuclear industry. In this study, the biokinetics of nearly pure, high specific activity {sup 237}Pu are compared with those of lower specific activity, impure {sup 237}Pu containing significant amounts of alpha-emitting Pu, following administration to rats by intravenous injection as the citrate. Both the distribution and excretion of the pure and impure {sup 237}Pu used in the two studies were similar and also in good agreement with the results of previously reported studies using {sup 239}Pu and {sup 241}Pu citrate, thus validating the use of {sup 237}Pu for studies of Pu metabolism in man. Data on the biokinetics of {sup 237}Pu nitrate are also included.

  15. Redox reactions of Pu(IV) and Pu(III) in the presence of acetohydroxamic acid in HNO(3) solutions.

    PubMed

    Tkac, Peter; Precek, Martin; Paulenova, Alena

    2009-12-21

    The reduction of Pu(IV) in the presence of acetohydroxamic acid (HAHA) was monitored by vis-NIR spectroscopy. All experiments were performed under low HAHA/Pu(IV) ratios, where only the Pu(IV)-monoacetohydroxamate complex and Pu uncomplexed with HAHA were present in relevant concentrations. Time dependent concentrations of all absorbing species were resolved using molar extinction coefficients for Pu(IV), Pu(III), and the Pu(AHA)(3+) complex by deconvolution of spectra. From fitting of the experimental data by rate equations integrated by a numeric method three reactions were proposed to describe a mechanism responsible for the reduction and oxidation of plutonium in the presence of HAHA and HNO(3). Decomposition of Pu(AHA)(3+) follows a second order reaction mechanism with respect to its own concentration and leads to the formation of Pu(III). At low HAHA concentrations, a two-electron reduction of uncomplexed Pu(IV) with HAHA also occurs. Formed Pu(III) is unstable and slowly reoxidizes back to Pu(IV), which, at the point when all HAHA is decomposed, can be catalyzed by the presence of nitrous acid.

  16. Complementary Pu Resuspension Study at Palomares, Spain

    SciTech Connect

    Shinn, J

    2002-10-01

    Soil in an area near Palomares, Spain, was contaminated with plutonium as a result of a mid-air collision of U.S. military aircraft in January 1966. The assessment for potential inhalation dose can be found in Iranzo et al., (1987). Long-term monitoring has been used to evaluate remedial actions (Iranzo et al., 1988) and there are many supporting studies of the Pu contamination at Palomares that have been carried out by the Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT) in Madrid. The purpose of this study is to evaluate the resuspension of Pu from the soil in terms of Pu-concentrations in air and resuspension rates in a complementary investigation to those of CIEMAT but in an intensive short-term field effort. This study complements the resuspension studies of CIEMAT at Palomares with additional information, and with confirmation of their previous studies. Observed mass loadings (M) were an average of 70 mg/m{sup 3} with peaks in the daytime of 130 mg/m{sup 3} and low values at night below 30 {micro}g/m{sup 3}. The Pu-activity of aerosols (A) downwind of plot 2-1 was 0.12 Bq/g and the enhancement factor (E{sub f}) had a value of 0.3, which is low but similar to a typical value of 0.7 for other undisturbed sites. This E{sub f} value may increase further away from ground zero. The particle size distribution of the Pu in air measured by cascade impactors was approximately lognormal with a median aerodynamic diameter of 3.7 {micro}m and a geometric standard deviation of 3.5 in the respirable range. This peak midway between 1 ? m and 10 {micro}m in the respirable range is commonly observed. Daily fluctuations in the Pu concentration in air (C) detected by the UHV were lognormally distributed with a geometric standard deviation of 4.9 indicating that the 98th percentile would be 24 times as high as the median. Downwind of plot 2-1 the mean Pu concentration in air, C, was 8.5 {micro}Bq/m{sup 3}. The resuspension factor (Sf) was 2.4 x 10

  17. Self-irradiation of Pu, its alloys and compounds

    NASA Astrophysics Data System (ADS)

    Timofeeva, L. F.

    2000-07-01

    Self-irradiation of Pu, its alloys and compounds by products of known α-decomposition is a continuous complicated process, which includes numerous different phenomena. The accumulation of Pu decomposition products causes material structure and properties change. This problem is the subject of many works, most of them concerned with the behavior of Pu and its alloys at low (liquid He and N) temperatures. The survey is given of the results of our experiments connected with radiogenic helium behavior, crystal structure and properties of Pu metallic compounds and Pu oxide ceramics in a self-irradiation process at room temperature under isochronal heat treatments.

  18. New archeointensity data from French Early Medieval pottery production (6th-10th century AD). Tracing 1500 years of geomagnetic field intensity variations in Western Europe

    NASA Astrophysics Data System (ADS)

    Genevey, Agnès; Gallet, Yves; Jesset, Sébastien; Thébault, Erwan; Bouillon, Jérôme; Lefèvre, Annie; Le Goff, Maxime

    2016-08-01

    Nineteen new archeointensity results were obtained from the analysis of groups of French pottery fragments dated to the Early Middle Ages (6th to 10th centuries AD). They are from several medieval ceramic production sites, excavated mainly in Saran (Central France), and their precise dating was established based on typo-chronological characteristics. Intensity measurements were performed using the Triaxe protocol, which takes into account the effects on the intensity determinations of both thermoremanent magnetization anisotropy and cooling rate. Intensity analyses were also carried out on modern pottery produced at Saran during an experimental firing. The results show very good agreement with the geomagnetic field intensity directly measured inside and around the kiln, thus reasserting the reliability of the Triaxe protocol and the relevance of the quality criteria used. They further demonstrate the potential of the Saran pottery production for archeomagnetism. The new archeointensity results allow a precise and coherent description of the geomagnetic field intensity variations in Western Europe during the Early Medieval period, which was until now poorly documented. They show a significant increase in intensity during the 6th century AD, high intensity values from the 7th to the 9th century, with a minimum of small amplitude at the transition between the 7th and the 8th centuries and finally an important decrease until the beginning of the 11th century. Together with published intensity results available within a radius of 700 km around Paris, the new data were used to compute a master curve of the Western European geomagnetic intensity variations over the past 1500 years. This curve clearly exhibits five intensity maxima: at the transition between the 6th and 7th century AD, at the middle of the 9th century, during the 12th century, in the second part of the 14th century and at the very beginning of the 17th century AD. Some of these peaks are smoothed, or

  19. Comparative study of the fragments' mass and energy characteristics in the spontaneous fussion of 238Pu, 240Pu and 242Pu and in the thermal-neutron-induced fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Schillebeeckx, P.; Wagemans, C.; Deruytter, A. J.; Barthélémy, R.

    1992-08-01

    The energy and mass distribution and their correlations have been studied for the spontaneous fission of 238, 240, 242Pu and for the thermal-neutron-induced fission of 239Pu. A comparison of 240Pu(s.f.) and 239Pu(nth,f) shows that the increase in excitation energy mainly results in an increase of the intrinsic excitation energy. A comparison of the results for 238Pu, 240Pu and 242Pu(s.f.) demonstrates the occurence of different fission modes with varying relative probability. These results are discussed in terms of the scission point model as well as in terms of the fission channel model with random neck-rupture.

  20. PuPO4(cr, hyd.) Solubility Product and Pu3+ Complexes With Phosphate and Ethylenediaminetetraacetic Acid

    SciTech Connect

    Rai, Dhanpat; Moore, Dean A.; Felmy, Andrew R.; Rosso, Kevin M.; Bolton, Harvey

    2010-06-15

    To determine the solubility product of PuPO4(cr, hyd.) and the complexation constants of Pu(III) with phosphate and EDTA, the solubility of PuPO4(cr, hyd.) was investigated as a function of: 1) time and pH varying from 1.0 to 12.0 and at a fixed 0.00032 M phosphate concentration; 2) NaH2PO4 concentrations varying from 0.0001 M to 1.0 M and at a fixed pH value of 2.5; 3) time and pH varying from 1.3 to 13.0 at fixed concentrations of 0.00032 M phosphate and 0.0004 M or 0.002 M Na2H2EDTA; and 4) Na2H2EDTA concentrations varying from 0.00005 M to 0.0256 M at a fixed 0.00032 M phosphate concentration and at pH values of approximately 3.5, 10.6, and 12.6. A combination of solvent extraction and spectrophotometric techniques confirmed that the use of hydroquinone and Na2S2O4 helped maintain Pu as Pu(III). The solubility data were interpreted using Pitzer and SIT models, and both provided similar values for the solubility product of PuPO4(cr, hyd.) and for the formation constant of PuEDTA-. The log10 of the solubility product of PuPO4(cr, hyd.) (PuPO4(cr, hyd.) = Pu3+ + PO4 ) was determined to be –(24.42 ± 0.38). Pitzer modeling showed that phosphate interactions with Pu3+ were extremely weak and did not require any phosphate complexes (e.g., PuPO4(aq), PuH2PO42+, Pu(H2PO4)2+, Pu(H2PO4)3(aq), and Pu(H2PO4)4-), as proposed in existing literature, to explain the experimental data. SIT modeling, however, required the inclusion of PuH2PO42+ to explain the data in high NaH2PO4 concentrations; this illustrates the differences one can expect when using these two chemical models to interpret the data. As the Pu(III)-EDTA species, only PuEDTA- was needed to interpret the experimental data in a large range in pH values (1.3–12.9) and EDTA concentrations (0.00005–0.256 M). Calculations based on density functional theory support the existence of PuEDTA- (with prospective stoichiometry as Pu(OH2)3EDTA-) as the chemically and structurally stable species. The log10 of the

  1. Comparison of Values in 5th, 6th, 7th and 8th Grade Primary Education Music Class Students'? Workbooks According to Rokeach?s and Akbas's Value Classifications

    ERIC Educational Resources Information Center

    Çakirer, H. Serdar

    2014-01-01

    The aim of the present study is to compare the values in the songs of 5th, 6th, 7th and 8th grade primary education music classes students? workbooks according to the value categorizations proposed by Rockeach and Akbas and which values among the categories mentioned are taught to the students in the 5th, 6th, 7th and 8th grade primary education…

  2. The geochemical coherence of Pu and Nd and the Pu-244/U-238 ratio of the early solar system

    NASA Technical Reports Server (NTRS)

    Jones, J. H.

    1982-01-01

    Two very different sets of Pu-244/U-238 ratios have been reported for early solar system materials, one high and the other low, and this paper examines how one of these groups may yield an incorrect ratio. Recently measured partition coefficients for Pu and Sm (Jones, 1981) are used to evaluate Pu-Nd fractionation during achondrite genesis, and Pu-244/U-238 ratios of chondrites, achondrites, and Ca-Al-rich inclusions are compared and discussed. A low Pu-244/U-238 ratio is favored, and some implications of this low ratio for galactic nucleosynthesis and meteorite age dating are briefly discussed.

  3. ²³⁹Pu and ²⁴⁰Pu inventories and ²⁴⁰Pu/²³⁹Pu atom ratios in the equatorial Pacific Ocean water column.

    PubMed

    Yamada, Masatoshi; Zheng, Jian

    2012-07-15

    The (239+240)Pu concentrations and (240)Pu/(239)Pu atom ratios were determined by alpha spectrometry and inductively coupled plasma mass spectrometry for seawater samples from two stations, one at the equator and the other in the equatorial South Pacific. To better understand the fate of Pu isotopes, this study dealt with the contribution of the close-in fallout Pu from the Pacific Proving Grounds (PPG) in water columns of the Pacific Ocean. The (239)Pu, (240)Pu and (239+240)Pu inventories over the depth interval 0-3000 m at the equator station were 10.4, 8.9 and 19.3 Bq m(-2), respectively. Further, no noticeable difference was observed in (239)Pu, (240)Pu and (239+240)Pu inventories over the depth interval 0-3000 m between the two stations. The total (239+240)Pu inventories were significantly higher than the expected cumulative deposition density of global fallout. Water column (239+240)Pu inventories measured in this study were lower than those reported for comparable stations in the Geochemical Ocean Sections Study, indicating that these inventories have been decreasing at average rates of 0.89 ± 0.07 and 0.16 ± 0.07 Bq m(-2)yr(-1) at the equator and equatorial South Pacific stations, respectively, from 1973 to 1990. The obtained (240)Pu/(239)Pu atom ratios were higher than the mean global fallout ratio of 0.18. These high atom ratios proved the existence of close-in tropospheric fallout Pu from the PPG in the Marshall Islands. The (239+240)Pu inventories originating from the close-in fallout in the entire water column were estimated to be 11.1 Bq m(-2) at the equator station and 7.1 Bq m(-2) at the equatorial South Pacific Ocean station, and the relative percentages of close-in fallout Pu were 40% at the former and 34% at the latter. A significant amount of close-in fallout Pu originating from the PPG has been transported to deep layers below the 1000 m depth in the equatorial Pacific Ocean.

  4. Fabrication of a 238Pu target

    SciTech Connect

    Wu, C Y; Chyzh, A; Kwan, E; Henderson, R; Gostic, J; Carter, D

    2010-11-16

    Precision neutron-induced reaction data are important for modeling the network of isotope production and destruction within a given diagnostic chain. This network modeling has many applications such as the design of advanced fuel cycle for reactors and the interpretation of radiochemical data related to the stockpile stewardship and nuclear forensics projects. Our current funded effort is to improve the neutron-induced reaction data on the short-lived actinides and the specific goal is to improve the neutron capture data on {sup 238}Pu with a half-life of 87.7 years. In this report, the fabrication of a {sup 238}Pu target for the proposed measurement using the DANCE array at LANL is described. The {sup 238}Pu target was fabricated from a sample enriched to 99.35%, acquired from ORNL. A total of 395 {micro}g was electroplated onto both sides of a 3 {micro}m thick Ti foil using a custom-made plating cell, shown in Fig 1. The target-material loaded Ti foil is sandwiched between two double-side aluminized mylar foils with a thickness of 1.4 {micro}m. The mylar foil is glued to a polyimide ring. This arrangement is shown partially in Fig. 2. The assembled target is then inserted into an aluminum container with a wall thickness of 0.76 mm, shown in Fig. 3. A derlin ring is used to keep the target assembly in place. The ends of this cylindrical container are vacuum-sealed by two covers with thin Kapton foils as windows for the beam entrance and exit. Shown in Fig. 4 is details of the arrangement. This target is used for phase I of the proposed measurement on {sup 238}Pu scheduled for Nov 2010 together with the DANCE array to address the safety issues raised by LANL. Shown in Fig. 5 is the preliminary results on the yield spectrum as a function of neutron incident energy with a gate on the total {gamma}-ray energy of equivalent Q value. Since no fission PPAC is employed, the distinction between the capture and fission events cannot be made, which is important for the

  5. Islet cell research brings hope for a diabetes cure: meeting report from the 6(th) annual islet society meeting in Stellenbosch, South Africa.

    PubMed

    Tchokonte-Nana, V; Cockburn, I L; Manda, J K; Kotze, P C; Johnson, J D

    2014-01-01

    The International Diabetes Federation predicts that, over the next twenty years, the largest increase in the prevalence of diabetes will be in the Africa region. Recognizing an unmet need for more focus on Africa and engagement with African scholars, the Islet Society held its 6th annual meeting July 20-21, 2014 in Stellenbosch, South Africa. Here, we present a report that covers the presentations and discussion points from that meeting. Work was presented on a variety of topics and included presentations by a significant proportion of Africa diabetes researchers. Overall, it was an excellent conference, with many new international collaborations initiated. We hope that other groups will also respond to the need for more conferences in Africa and focused on Africa.

  6. Nevada test site fallout atom ratios: /sup 240/Pu//sup 239/Pu and /sup 241/Pu//sup 239/Pu

    SciTech Connect

    Hicks, H.G.; Barr, D.W.

    1984-02-01

    The exposure of the population in Utah to external gamma radiation from the fallout from nuclear weapons tests carried out between 1951 and 1958 at the Nevada Test Site (NTS) has been reconstructed from recent measurements of /sup 137/Cs and plutonium in soil. The fraction of /sup 137/Cs in the fallout from NTS events was calculated from the total plutonium and the /sup 240/Pu//sup 239/Pu ratios measured in the soil, using the values of 0.180 +- 0.006 and 0.032 +- 0.003 for that ratio in global fallout and NTS fallout, respectively. The total population exposure from NTS events was then calculated on the basis of exposure rates resulting from short-lived radionuclides associated with the /sup 137/Cs at the time of deposition. While the /sup 240/Pu//sup 239/Pu ratio is constant in global fallout, this ratio varies greatly in the fallout from individual events. While the composition of fallout on Utah from NTS events is rather uniform, the Off-Site Radiation Exposure Review Project is currently reconstructing radiation exposures for locations close to NTS where the fallout may be predominantly from one event. Therefore, the authors compiled the pertinent ratios in order to provide information concerning the exposure resulting from any individual event. The plutonium ratios measured at 30 days postshot were compiled from unpublished values in the archives of the Nuclear Chemistry Division of LLNL and INC-11 of LANL. These ratios are pertinent to fallout data. Dates for each event were taken from a publication by the Nevada Operations Office of the Department of Energy. 3 references.

  7. Climate Change and the Water Cycle: A New Southwest Regional Climate Hub Curriculum Unit for 6th-12th Grade Students

    NASA Astrophysics Data System (ADS)

    Elias, E.; Steele, C. M.; Bestelmeyer, S.; Haan-Amato, S.; Deswood, H.; Rango, A.; Havstad, K.

    2015-12-01

    As climate change intensifies, increased temperatures and altered precipitation will make water, a limited resource in the arid southwestern United States, even scarcer in many locations. The USDA Southwest Regional Climate Hub (SWRCH) developed Climate Change and the Water Cycle, an engaging and scientifically rigorous education unit for 6th -12th grade students. The unit is aligned with Common Core State Standards and Next Generation Science Standards. Nine activities can be conducted over 10 instruction hours. Each activity can also stand alone. In partnership with SWRCH, the Asombro Institute for Science Education developed the unit. Each activity was reviewed by an educator for educational practices and by a scientist for scientific accuracy. The unit was pilot tested with 524 students in 2014, and pre- and post-tests were administered. Ninety-one percent of students were able to name a greenhouse gas on the post-test, compared to only 48% on the pre-test. On the post-test, 86% of students identified the relationship between average global temperature and carbon dioxide levels in the atmosphere, compared to only 52% on the pre-test. A student commented: "I loved all of the activities! They are fun and help us understand about what goes on in the world." Educators who participated in pilot testing said: "the entire curriculum is great, but I was particularly impressed with the progression of ideas and the variety of lessons," and "students could see the relevance and importance of these real life issues." Anyone interested in using the unit to host workshops for teachers in southwestern states should contact Asombro for more information (information@asombro.org). The Climate Change and the Water Cycle 6th-12th grade curriculum unit is available online: www.swclimatehub.info/education/climate-change-and-water-cycle

  8. Prognostic Impact of the 6th and 7th American Joint Committee on Cancer TNM Staging Systems on Esophageal Cancer Patients Treated With Chemoradiotherapy

    SciTech Connect

    Nomura, Motoo; Shitara, Kohei; Kodaira, Takeshi; Hatooka, Shunzo; Mizota, Ayako; Kondoh, Chihiro; Yokota, Tomoya; Takahari, Daisuke; Ura, Takashi; Muro, Kei

    2012-02-01

    Purpose: The new 7th edition of the American Joint Committee on Cancer TNM staging system is based on pathologic data from esophageal cancers treated by surgery alone. There is no information available on evaluation of the new staging system with regard to prognosis of patients treated with chemoradiotherapy (CRT). The objective of this study was to evaluate the prognostic impact of the new staging system on esophageal cancer patients treated with CRT. Methods and Materials: A retrospective review was performed on 301 consecutive esophageal squamous cell carcinoma patients treated with CRT. Comparisons were made of the prognostic impacts of the 6th and 7th staging systems and the prognostic impacts of stage and prognostic groups, which were newly defined in the 7th edition. Results: There were significant differences between Stages I and III (p < 0.01) according to both editions. However, the 7th edition poorly distinguishes the prognoses of Stages III and IV (p = 0.36 by multivariate analysis) in comparison to the 6th edition (p = 0.08 by multivariate analysis), although these differences were not significant. For all patients, T, M, and gender were independent prognostic factors by multivariate analysis (p < 0.05). For the Stage I and II prognostic groups, survival curves showed a stepwise decrease with increase in stage, except for Stage IIA. However, there were no significant differences seen between each prognostic stage. Conclusions: Our study indicates there are several problems with the 7th TNM staging system regarding prognostic factors in patients undergoing CRT.

  9. 240Pu/239Pu isotopic ratios and 239 + 240Pu total measurements in surface and deep waters around Mururoa and Fangataufa atolls compared with Rangiroa atoll (French Polynesia).

    PubMed

    Chiappini, R; Pointurier, F; Millies-Lacroix, J C; Lepetit, G; Hemet, P

    1999-09-30

    The average values of 240Pu/239Pu mass isotopic ratios of plutonium deposited in Mururoa and Fangataufa atoll sediments by French atmospheric nuclear tests range from 3.5 to 5%. In order to assess the near field and far field influence of those deposits in the open ocean, two water profiles were measured for 239 + 240Pu and 240Pu/239Pu using, for the first time, an Inductively Coupled Plasma Mass Spectrometer which was developed to achieve femtogram detection limits. One site was located at the limit of the French territorial waters, which is 22 km distant from Mururoa. The second site was located close to Rangiroa atoll, at a distance of approximately 1200-km from French nuclear test sites. The sample volumes were approximately 500 litres and plutonium was purified prior to mass spectrometry and alpha spectrometry measurements. In Rangiroa, the 239 + 240Pu profile is comparable with those already determined in world open oceans but the maximum detected activity, 9 mBq/m3 at 500-600 m is a lot lower than those measured in the northern hemisphere. 240Pu/239Pu ratios were measured between 500 and 1000 m and were not statistically different from the typical 0.18 +/- 0.01 ratio which characterises the global fallout. Consequently, any influence of plutonium from the tests in Mururoa and Fangataufa is not apparent at Rangiroa. The vertical distribution of 239 + 240Pu near Mururoa shows similar changes with depth but with a slight increase in concentration. 240Pu/239Pu mass ratios vary with depth, from 7 to 10% in the upper 500 m and in the deep waters (below 1000 m) to 15-16% between 600 and 1000 m. A contribution from plutonium deposited in the sediments at Mururoa and Fangataufa is observed at the limit of territorial waters, especially in surface and deep waters.

  10. The 6th FDR prize

    NASA Astrophysics Data System (ADS)

    Funakoshi, Mitsuaki

    2013-06-01

    From the 58 papers published in 2012 in Fluid Dynamics Research, the following paper has been selected for the sixth FDR prize: The finite-difference lattice Boltzmann method and its application in computational aero-acoustics by Michihisa Tsutahara (Professor Emeritus, Kobe University, Japan), published in volume 44 (August 2012) 045507. This is a review paper of the author's recent work on the finite-difference lattice Boltzmann method (FDLBM). In this paper, the author introduces a modified FDLBM and its application to aero-acoustics. To solve the discrete Bhatnager, Gross and Krook equation for simulating fluid flow, the FDLBM applies a stable finite-difference scheme on a curvilinear coordinate system, whereas the ordinary lattice Boltzmann method uses regular lattices. It is known that for the lattice Boltzmann methods, there is difficulty in simulating high Mach number compressible flows in principle. To alleviate this, the author proposed the modified FDLBM, expanding the flexibility of setting time increments. With this FDLBM, the author has shown that it is possible to simulate compressible flows efficiently around complex bluff bodies and with complex aero-acoustic behaviour. The author summarizes all those works, including studies only available in Japanese up to now, in this review paper. After discussing the details of the FDLBM proposed by the author, example results of simulating the Aeolian tone generated from a circular cylinder at the Mach number M = 0.7 are shown. Then, the scheme is expanded for moving bodies by combining with the Arbitrary Lagrangian Eulerian formulation. Using this moving mesh scheme, the author shows the simulation results of the very strong sound pressure generated by a high-speed train in a tunnel. For issues of sound propagation in compressible two-phase flows whose density ratio is high, the two-particle model is introduced. Also, techniques to reduce noise generation from the flow velocity and pressure at gas-liquid interfaces are shown. Finally, the scattering of sound waves by water droplets is discussed. In thick fog, the sound coming from a distance becomes faint due to the sound-scattering effects of micro water droplets. The author gives an example of successfully solving such an issue by the FDLBM. It is highly admirable that the author developed the new FDLBM for aero-acoustic issues and has summarized it with sub-schemes to overcome several difficulties of engineering aeroacoustics in this review. It will certainly contribute to further development of fluid dynamics through computational aero-acoustics. Consequently, this paper was selected as the winner of the sixth FDR prize.

  11. Electronic Structure Calculations of delta-Pu Based Alloys

    SciTech Connect

    Landa, A; Soderlind, P; Ruban, A

    2003-11-13

    First-principles methods are employed to study the ground-state properties of {delta}-Pu-based alloys. The calculations show that an alloy component larger than {delta}-Pu has a stabilizing effect. Detailed calculations have been performed for the {delta}-Pu{sub 1-c}Am{sub c} system. Calculated density of Pu-Am alloys agrees well with the experimental data. The paramagnetic {yields} antiferromagnetic transition temperature (T{sub c}) of {delta}-Pu{sub 1-c}Am{sub c} alloys is calculated by a Monte-Carlo technique. By introducing Am into the system, one could lower T{sub c} from 548 K (pure Pu) to 372 K (Pu{sub 70}Am{sub 30}). We also found that, contrary to pure Pu where this transition destabilizes {delta}-phase, Pu{sub 3}Am compound remains stable in the antiferromagnetic phase that correlates with the recent discovery of a Curie-Weiss behavior of {delta}-Pu{sub 1-c}Am{sub c} at c {approx} 24 at. %.

  12. X-ray excited Auger transitions of Pu compounds

    SciTech Connect

    Nelson, Art J. Grant, William K.; Stanford, Jeff A.; Siekhaus, Wigbert J.; Allen, Patrick G.; McLean, William

    2015-05-15

    X-ray excited Pu core–valence–valence and core–core–valence Auger line-shapes were used in combination with the Pu 4f photoelectron peaks to characterize differences in the oxidation state and local electronic structure for Pu compounds. The evolution of the Pu 4f core-level chemical shift as a function of sputtering depth profiling and hydrogen exposure at ambient temperature was quantified. The combination of the core–valence–valence Auger peak energies with the associated chemical shift of the Pu 4f photoelectron line defines the Auger parameter and results in a reliable method for definitively determining oxidation states independent of binding energy calibration. Results show that PuO{sub 2}, Pu{sub 2}O{sub 3}, PuH{sub 2.7}, and Pu have definitive Auger line-shapes. These data were used to produce a chemical state (Wagner) plot for select plutonium oxides. This Wagner plot allowed us to distinguish between the trivalent hydride and the trivalent oxide, which cannot be differentiated by the Pu 4f binding energy alone.

  13. Sintering of compacts of UN, (U,Pu)N, and PuN

    DOEpatents

    Tennery, V.J.; Godfrey, T.G.; Bomar, E.S.

    1973-10-16

    >A method is provided for preparing a densified compact of a metal nitride selected from the group consisting of UN, (U,Pu)N, and PuN which comprises heating a green compact of at least one selected nitride in the mononitride single-phase region, as displayed by a phase diagram of the mononitride of said compact, in a nitrogen atmosphere at a pressure of nitrogen less than 760 torr. At a given temperature, this process produces a singlephase structure and a maximal sintered density as measured by mercury displacement. (Official Gazette)

  14. Materials compatibility for 238Pu-HNO3/HF solution containment: 238Pu aqueous processing

    NASA Astrophysics Data System (ADS)

    Reimus, M. A.; Pansoy-Hjelvik, M. E.; Silver, G.; Brock, J.; Nixon, J.; Ramsey, K. B.; Moniz, P.

    2000-07-01

    The Power Source Technologies Group at Los Alamos National Laboratory is building a 238Pu Aqueous Scrap Recovery Line at the Plutonium Facility. The process line incorporates several unit operations including dissolution, filtration, ion exchange, and precipitation. During 1997-1999, studies were carried out to determine the chemistry used in the full-scale process. Other studies focussed on the engineering design of the operation. Part of the engineering design was to determine, in compatibility studies, the materials for reaction and storage vessels which will contain corrosive 238Pu-HNO3/HF solutions. The full-scale line is to be operational by the end of year 2000.

  15. Adsorption behaviour of PuF6 on UO2F2 by the use of 236Pu

    NASA Astrophysics Data System (ADS)

    Sato, Nobuaki; Matsuda, Minoru; Mitsugashira, Toshiaki; Kirishima, Akira

    2010-03-01

    To know the behavior of plutonium in the fluoride volatility process (FLUOREX PROCESS) for the spent nuclear fuel, both UO2 and PuO2 are fluorinated by fluorine forming volatile UF6 and PuF6, respectively. Then PuF6 is separated and recovered from UF6 by using adsorption materials such as uranyl fluoride UO2F2. In this paper, adsorption behavior of PuF6on UO2F2 was examined by the use of 236Pu tracer. First, the stability of UO2F2 in F2atmosphere was analyzed by TG-DTA method showing that uranium volatilized completely over 350 °C by the formation of UF6 and the adsorption of plutonium by UO2F2 should be done at temperatures lower than 250 °C. The behavior of PtF6 as a chemical analogue of PuF6 was also conducted for comparison and it showed that the deposition of PtF4 on UO2F2 at 200 °C. When the 236Pu doped U3O8 was reacted with 10%F2-He gas, the PuF6 vaporized at ca. 600 °C. Then adsorption of 236Pu on UO2F2 was observed by α ray measurement. The adsorption mechanism of Pu on UO2F2 was discussed with experimental data and thermodynamic consideration.

  16. Characterization of a Pu-bearing zirconolite-rich synroc

    SciTech Connect

    Buck, E.C.; Ebbinghaus, B.; Bakel, A.J.; Bates, J.K.

    1996-12-31

    A titanate-based ceramic waste form, rich in phases structurally related to zirconolite (CaZrTi{sub 2}O{sub 7}), is being developed as a possible method for immobilizing excess plutonium from dismantled nuclear weapons. As part of this program, Lawrence Livermore National Laboratory (LLNL) produced several ceramics that were then characterized at Argonne National Laboratory (ANL). The plutonium- loaded ceramic was found to contain a Pu-Gd zirconolite phase but also contained plutonium titanates, Gd-polymignyte, and a series of other phases. In addition, much of the Pu was remained as PuO{sub 2- x}. The Pu oxidation state in the zirconolite was determined to be mainly Pu{sup 4+}, although some Pu{sub 3+} was believed to be present.

  17. Iron Corrosion Observations: Pu(VI)-Fe Reduction Studies

    SciTech Connect

    Reed, Donald T.; Swanson, Juliet S.; Richmann, Michael K.; Lucchini, Jean-Francois; Borkowski, Marian

    2012-09-11

    Iron and Pu Reduction: (1) Very different appearances in iron reaction products were noted depending on pH, brine and initial iron phase; (2) Plutonium was associated with the Fe phases; (3) Green rust was often noted at the higher pH; (4) XANES established the green rust to be an Fe2/3 phase with a bromide center; and (5) This green rust phase was linked to Pu as Pu(IV).

  18. Evidence of strong Quaternary earthquakes in the epicentral areaof the April 6th 2009 L'Aquila seismic event from sediment paleofluidization and overconsolidation

    NASA Astrophysics Data System (ADS)

    Storti, F.; Balsamo, F.; Aldega, L.; Corrado, S.; Di Paolo, L.; Mastalertz, M.; Tallini, M.

    2012-04-01

    The strong seismological potential of the Central Apennines, including the L'Aquila basin, is documented in the historical heritage of the past two millenia and by paleoseismological data. Despite the main active fault system network of Central Italy is well described and mapped, the April 6th 2009 L'Aquila event showed that Mw> 6.0 earthquakes can occur on fault zones characterized by subtlemorphotectonic evidence, like the Paganica Fault, whose seismic hazard potential may thus be overlooked. An additional source of uncertainty is provided by the evidence that in the L'Aquila region many active extensional fault systems developed by negative inversion of pre-existing contractional deformation structures. The resulting complex along-strike segmentation and overlap patterns are thus governed by the interplay between the modern extensional stress field and the structural inheritance and reduce the effectiveness of predictive scaling laws, which do not typically account for fault attributes produced by polyphased tectonics. This is particularly true in the L'Aquila region, where seismic activation of the northwestern half of the basin-boundary fault system has been proposed for the 1703 Mw ~ 7.0 earthquake, whereas only the central segment was activated in 1461 and 2009, producing earthquakes with Mw ~ 6.0 - 6.3. The reasons for this dual behaviour are still unclear despite many structural and paleoseismological studies. Indirect evidence for paleoearthquake magnitude from ground shaking effects, like paleo-fluidization structures, can provide very useful complementary information on maximum expected earthquake intensities along active fault systems.In this work wedescribe in detail large paleo-fluidization-induced features associated with a previously unmapped extensional fault zone cutting through Quaternary strata. These sediments, including lacustrine lignites and mudstones, show a somehow enigmatic overconsolidation that we quantitatively describe, as well as

  19. 5/6th nephrectomy in combination with high salt diet and nitric oxide synthase inhibition to induce chronic kidney disease in the Lewis rat.

    PubMed

    van Koppen, Arianne; Verhaar, Marianne C; Bongartz, Lennart G; Joles, Jaap A

    2013-07-03

    Chronic kidney disease (CKD) is a global problem. Slowing CKD progression is a major health priority. Since CKD is characterized by complex derangements of homeostasis, integrative animal models are necessary to study development and progression of CKD. To study development of CKD and novel therapeutic interventions in CKD, we use the 5/6th nephrectomy ablation model, a well known experimental model of progressive renal disease, resembling several aspects of human CKD. The gross reduction in renal mass causes progressive glomerular and tubulo-interstitial injury, loss of remnant nephrons and development of systemic and glomerular hypertension. It is also associated with progressive intrarenal capillary loss, inflammation and glomerulosclerosis. Risk factors for CKD invariably impact on endothelial function. To mimic this, we combine removal of 5/6th of renal mass with nitric oxide (NO) depletion and a high salt diet. After arrival and acclimatization, animals receive a NO synthase inhibitor (NG-nitro-L-Arginine) (L-NNA) supplemented to drinking water (20 mg/L) for a period of 4 weeks, followed by right sided uninephrectomy. One week later, a subtotal nephrectomy (SNX) is performed on the left side. After SNX, animals are allowed to recover for two days followed by LNNA in drinking water (20 mg/L) for a further period of 4 weeks. A high salt diet (6%), supplemented in ground chow (see time line Figure 1), is continued throughout the experiment. Progression of renal failure is followed over time by measuring plasma urea, systolic blood pressure and proteinuria. By six weeks after SNX, renal failure has developed. Renal function is measured using 'gold standard' inulin and para-amino hippuric acid (PAH) clearance technology. This model of CKD is characterized by a reduction in glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), hypertension (systolic blood pressure>150 mmHg), proteinuria (> 50 mg/24 hr) and mild uremia (>10 mM). Histological

  20. Effect of equilibration time on Pu desorption from goethite

    DOE PAGES

    Wong, Jennifer C.; Zavarin, Mavrik; Begg, James D.; Kersting, Annie B.; Powell, Brian A.

    2015-01-28

    Strongly sorbing ions such as plutonium may become irreversibly bound to mineral surfaces over time implicates near- and far-field transport of Pu. Batch adsorption–desorption data were collected as a function of time and pH to study the surface stability of Pu on goethite. Pu(IV) was adsorbed to goethite over the pH range 4.2 to 6.6 for different periods of time (1, 6, 15, 34 and 116 d). Moreover, following adsorption, Pu was leached from the mineral surface with desferrioxamine B (DFOB), a complexant capable of effectively competing with the goethite surface for Pu. The amount of Pu desorbed from the goethitemore » was found to vary as a function of the adsorption equilibration time, with less Pu removed from the goethite following longer adsorption periods. This effect was most pronounced at low pH. Logarithmic desorption distribution ratios for each adsorption equilibration time were fit to a pH-dependent model. Model slopes decreased between 1 and 116 d adsorption time, indicating that overall Pu(IV) surface stability on goethite surfaces becomes less dependent on pH with greater adsorption equilibration time. The combination of adsorption and desorption kinetic data suggest that non-redox aging processes affect Pu sorption behavior on goethite.« less

  1. Effect of equilibration time on Pu desorption from goethite

    SciTech Connect

    Wong, Jennifer C.; Zavarin, Mavrik; Begg, James D.; Kersting, Annie B.; Powell, Brian A.

    2015-01-28

    Strongly sorbing ions such as plutonium may become irreversibly bound to mineral surfaces over time implicates near- and far-field transport of Pu. Batch adsorption–desorption data were collected as a function of time and pH to study the surface stability of Pu on goethite. Pu(IV) was adsorbed to goethite over the pH range 4.2 to 6.6 for different periods of time (1, 6, 15, 34 and 116 d). Moreover, following adsorption, Pu was leached from the mineral surface with desferrioxamine B (DFOB), a complexant capable of effectively competing with the goethite surface for Pu. The amount of Pu desorbed from the goethite was found to vary as a function of the adsorption equilibration time, with less Pu removed from the goethite following longer adsorption periods. This effect was most pronounced at low pH. Logarithmic desorption distribution ratios for each adsorption equilibration time were fit to a pH-dependent model. Model slopes decreased between 1 and 116 d adsorption time, indicating that overall Pu(IV) surface stability on goethite surfaces becomes less dependent on pH with greater adsorption equilibration time. The combination of adsorption and desorption kinetic data suggest that non-redox aging processes affect Pu sorption behavior on goethite.

  2. Ferro- and antiferro-magnetism in (Np, Pu)BC

    NASA Astrophysics Data System (ADS)

    Klimczuk, T.; Shick, A. B.; Kozub, A. L.; Griveau, J.-C.; Colineau, E.; Falmbigl, M.; Wastin, F.; Rogl, P.

    2015-04-01

    Two new transuranium metal boron carbides, NpBC and PuBC, have been synthesized. Rietveld refinements of powder XRD patterns of {Np,Pu}BC confirmed in both cases isotypism with the structure type of UBC. Temperature dependent magnetic susceptibility data reveal antiferromagnetic ordering for PuBC below TN = 44 K, whereas ferromagnetic ordering was found for NpBC below TC = 61 K. Heat capacity measurements prove the bulk character of the observed magnetic transition for both compounds. The total energy electronic band structure calculations support formation of the ferromagnetic ground state for NpBC and the antiferromagnetic ground state for PuBC.

  3. Partnering to change the world for people with haemophilia: 6(th) Haemophilia Global Summit, Prague, Czech Republic, 24-26(th) September 2015.

    PubMed

    Astermark, Jan; Hart, Dan; Lobet, Sébastien; Blatný, Jan; d'Oiron, Roseline; Kenet, Gili; Dolan, Gerry; Libotte, Valérie; Hermans, Cedric

    2016-07-01

    The 6(th) Haemophilia Global Summit was held in Prague, Czech Republic, in September 2015. The programme was designed by an independent Scientific Steering Committee of haemophilia experts and aimed to share optimal management strategies for haemophilia at all life stages, explore recent potential advances in the management of haemophilia A and B and discuss challenges in haemophilia care. In this supplement from the meeting, Dan Hart reviews the lessons that can be learnt from cost-constrained environments with regard to improving care for people with haemophilia globally. Sébastien Lobet discusses the importance of physical activity for optimising care and Roseline d'Oiron and Jan Blatný consider the role of real-world data in understanding the effect of treatment in a clinical setting over the long term and the true impact of treatment on the day-to-day life of the patient. Gili Kenet addresses the current challenges relating to the optimal management of prophylaxis, and Gerry Dolan and Cedric Hermans discuss the value of pharmacokinetic (PK) parameters in informing treatment decisions. Cedric Hermans and Valérie Libotte explore the importance of considering social and occupational development factors as an integral part of haemophilia care, and Jan Astermark reviews key strategies to predict and prevent inhibitor development.

  4. The Hetu'u Global Network: Using the rare June 5th/6th Transit of Venus to Bring Astronomy to the Remote Easter Island

    NASA Astrophysics Data System (ADS)

    Faherty, Jacqueline; Rodriguez, D.

    2013-01-01

    There are rare times in astronomy when a celestial event, visible in broad daylight, can be used to measure a fundamental parameter and inspire a globe full of school age students. The June 5th/6th transit of Venus was one such event. In celebration, nine astronomy postdocs from the Chilean mainland traveled to Easter Island to lead a series of astronomy outreach activities over three days, culminating in a transit-viewing event. Our team dubbed "Equipo Hetu'u" or "Team Star" in the Rapa Nui (Easter Island native) language spent two days giving astronomy talks and doing hands-on demonstrations at the Museo Antropologico P. Sebastian Englert. In the final day-and-a-half leading up to the transit, we visited the science classes in the majority of the schools on the island, in order to spread the message about the once-in-a-lifetime transit event, highlighting how we planned on using it to measure the distance to the Sun. We estimate over 25% 1500 people) of this remote island participated in one or more of our organized activities. Our experience with this project is an excellent lesson on how to organize, lead, and fully execute a major outreach endeavor that inspires hundreds with minimal resources (save the spectacular event provided by the cosmos).

  5. The Beginning of Metallurgy in the Southern Levant: A Late 6th Millennium CalBC Copper Awl from Tel Tsaf, Israel

    PubMed Central

    Garfinkel, Yosef; Klimscha, Florian; Shalev, Sariel; Rosenberg, Danny

    2014-01-01

    The beginning of metallurgy in the ancient Near East attracts much attention. The southern Levant, with the rich assemblage of copper artifacts from the Nahal Mishmar cave and the unique gold rings of the Nahal Qanah cave, is regarded as a main center of early metallurgy during the second half of the 5th millennium CalBC. However, a recently discovered copper awl from a Middle Chalcolithic burial at Tel Tsaf, Jordan Valley, Israel, suggests that cast metal technology was introduced to the region as early as the late 6th millennium CalBC. This paper examines the chemical composition of this item and reviews its context. The results indicate that it was exported from a distant source, probably in the Caucasus, and that the location where it was found is indicative of the social status of the buried individual. This rare finding indicates that metallurgy was first defused to the southern Levant through exchange networks and only centuries later involved local production. This copper awl, the earliest metal artifact found in the southern Levant, indicates that the elaborate Late Chalcolithic metallurgy developed from a more ancient tradition. PMID:24671185

  6. The beginning of metallurgy in the southern Levant: a late 6th millennium CalBC copper awl from Tel Tsaf, Israel.

    PubMed

    Garfinkel, Yosef; Klimscha, Florian; Shalev, Sariel; Rosenberg, Danny

    2014-01-01

    The beginning of metallurgy in the ancient Near East attracts much attention. The southern Levant, with the rich assemblage of copper artifacts from the Nahal Mishmar cave and the unique gold rings of the Nahal Qanah cave, is regarded as a main center of early metallurgy during the second half of the 5th millennium CalBC. However, a recently discovered copper awl from a Middle Chalcolithic burial at Tel Tsaf, Jordan Valley, Israel, suggests that cast metal technology was introduced to the region as early as the late 6th millennium CalBC. This paper examines the chemical composition of this item and reviews its context. The results indicate that it was exported from a distant source, probably in the Caucasus, and that the location where it was found is indicative of the social status of the buried individual. This rare finding indicates that metallurgy was first diffused [corrected] to the southern Levant through exchange networks and only centuries later involved local productionThis copper awl, the earliest metal artifact found in the southern Levant, indicates that the elaborate Late Chalcolithic metallurgy developed from a more ancient tradition.

  7. Meeting Report: "Proteomics from Discovery to Function:" 6th Annual Meeting of Proteomics Society, India and International Conference-A Milestone for the Indian Proteomics Community.

    PubMed

    Gupta, Shabarni; Reddy, Panga Jaipal; Ray, Sandipan; Atak, Apurva; Gollapalli, Kishore; Jain, Rekha; Shah, Veenita Grover; Ghantasala, Saicharan; Kumar, Saurabh; Pandala, Narendra Goud; Phapale, Prasad; Pandey, Vishnu Kumar; Zingde, Surekha; Srivastava, Sanjeeva

    2015-06-01

    Proteomics is at the epicenter of post-genomics biotechnologies that are currently driving the next generation system science. Moreover, proteomics is a truly global science. The 6(th) Annual Meeting of Proteomics Society, India (PSI) and International Conference on "Proteomics from Discovery to Function" held from December 7-9, 2014, was a transformative endeavor for global proteomics, bringing together the luminaries in the field of proteomics for the very first time in India. This meeting report presents the lessons learned and the highlights of this international scientific conference that was comprised of nine thematic sessions, pre- and post-conference workshops, and an opportunity to cultivate enduring collaborations for proteomics science to benefit both India and global society. The conference had an unforgettable impression on the participants: for the first time, India hosted past and present President and Council members from the Human Proteome Organization (HUPO), along with eminent scientists and young scholars from India and abroad in the field of proteomics at such a large scale, a major highlight of this international event. In all, the PSI 2014 was a milestone conference that has firmly poised the Indian life sciences community as a leading contributor to post-genomics life sciences, thus cultivating crucial trans-generational capacity and inspiration by recognizing the emerging scholars and omics systems scientists who can think and conduct science from cell to society.

  8. Vegetation dieback as a proxy for temperature within a wet pyroclastic density current: A novel experiment and observations from the 6th of August 2012 Tongariro eruption

    NASA Astrophysics Data System (ADS)

    Efford, Jackson T.; Bylsma, Rebecca J.; Clarkson, Bruce D.; Pittari, Adrian; Mauriohooho, Kate; Moon, Vicki G.

    2014-10-01

    The 6th of August 2012 eruption of Te Maari (Mt Tongariro, New Zealand) generated wet pyroclastic density currents (PDCs) which caused widespread dieback of vegetation (singed, brown foliage) in their path. An absence of significant charcoal formation suggests that PDC temperatures were mostly below 250 °C. Textural evidence for liquid water being present in the matrices during emplacement (vesicles) suggests that temperatures were < 100 °C. We determined a probable minimum PDC temperature using an experiment replicating the critical temperatures required to induce foliar browning in seven species affected by the eruption. In locations where all species exhibited browned foliage (or were defoliated), temperatures were probably ≥ 64 °C assuming a PDC duration of 60 s. In the more distal areas, where only the most susceptible species were browned while others remained healthy and unaffected, temperatures were probably around 51-58 °C. These results have relevance to volcanic hazard mitigation and risk assessment, especially on the popular Tongariro Alpine Crossing.

  9. Measurement of plutonium isotopes, 239Pu and 240Pu, in air-filter samples from Seville (2001-2002)

    NASA Astrophysics Data System (ADS)

    Chamizo, E.; García-León, M.; Enamorado, S. M.; Jiménez-Ramos, M. C.; Wacker, L.

    2010-05-01

    Since the last nuclear atmospheric test carried out by the People Republic of China in 1980 and since the Chernobyl accident in 1986, the plutonium hasn't been directly released into the atmosphere. However, nowadays, it is still present in the troposphere. This is due to plutonium-bearing soil particles physical resuspension processes. In this work, we study for the first time the temporal variation of plutonium isotopes, 239Pu and 240Pu, baseline concentrations on a monthly basis in surface air from Seville (Spain), and their correlation with some tracers of mineral dust, during 2001 and 2002. The Pu analyses were performed by low-energy Accelerator Mass Spectrometry (AMS). The 239Pu plus 240Pu ( 239+240Pu) activity levels achieved maximums during the summer period, characterized by the absence of rains, and minimums during the rainy seasons, laying in the range 1-20 nBq m -3. The 240Pu/ 239Pu two-year average atomic ratio was 0.18 ± 0.03, in agreement with the fallout plutonium. A good correlation with Pu and Al and Ti levels is observed. They are crustal components usually used as tracers of African dust over European countries. The hypothesis of the influence of the Saharan dust intrusions is supported as well through the study of Total Ozone Mass Spectrometer (TOMS) daily images.

  10. Free energy of formation of Cs 3PuCl 6 and CsPu 2Cl 7

    NASA Astrophysics Data System (ADS)

    Williamson, M. A.; Kleinschmidt, P. D.

    The free energy, enthalpy and entropy of formation of the compounds Cs 3PuCl 6 and CsPu 2Cl 7 have been determined by measuring the sublimation pressures for the reactions CsCl( s) / aiCsCl( g), {2}/{5}Cs 3PuCl 6(s) /ai {1}/{5}CsPu 2Cl 7(s) + CsCl(g) , and CsPu2Cl7( s) / ai 2 PuCl3( s) + CsCl( g). The pressures are measured using Knudsen effusion mass spectrometry over the temperature range 600 to 850 K. For the formation of Cs 3PuCl 6 from CsCl and PuCl 3, ΔG0298 = -77.3 ± 8.5 kJ/ mol, ΔH0298 = -82.1 ± 7.8 kJ/ mol, and ΔS0298 = -16.2 ± 10.9 J/ Kmol. For CsPu 2Cl 7, ΔG0298 = -39.4 ± 3.5 kJ/ mol, ΔH0298 = -40.8 ± 3.2 kJ/ mol, and ΔS0298 = -4.6 ± 4.2 J/ Kmol.

  11. Is Octavalent Pu(VIII) Possible? Mapping the Plutonium Oxyfluoride Series PuO(n)F(8-2n) (n = 0-4).

    PubMed

    Huang, Wei; Pyykkö, Pekka; Li, Jun

    2015-09-01

    While the oxidation state Pu(VIII) is shown to be less stable than Pu(V) in the PuO4 molecule, it is not clear if the more electronegative fluorine can help to stabilize Pu(VIII). Our calculations on PuO(n)F(8-2n) (n = 0-4) molecules notably confirm that PuO2F4 has both (1)D(4h) and (5)C(2v) minima with the oxidation states Pu(VIII) and Pu(V), respectively, with the latter having lower energy. The hybrid-DFT, CCSD(T), and CASSCF methods all give the same result. The results conform to a superoxide ligand when n ≥ 2. PuF8 in a (1)O(h) state can decompose to PuF6 and F2, and PuOF6 in a (1)C(2v) state also can break down to PuF6 and 1/2 O2. The Pu(VIII) anion PuO2F5(-) does have a D(5h) minimum, which also lies above a (5)C(2v) Pu(V) peroxide structure. However, the energy differences between the different minima are not large, indicating that metastable species with oxidation states higher than Pu(V) cannot be completely excluded.

  12. PU.1 silencing leads to terminal differentiation of erythroleukemia cells

    SciTech Connect

    Atar, Orna; Levi, Ben-Zion . E-mail: blevi@technion.ac.il

    2005-04-22

    The transcription factor PU.1 plays a central role in development and differentiation of hematopoietic cells. Evidence from PU.1 knockout mice indicates a pivotal role for PU.1 in myeloid lineage and B-lymphocyte development. In addition, PU.1 is a key player in the development of Friend erythroleukemia disease, which is characterized by proliferation and differentiation arrest of proerythrocytes. To study the role of PU.1 in erythroleukemia, we have used murine erythroleukemia cells, isolated from Friend virus-infected mice. Expression of PU.1 small interfering RNA in these cells led to significant inhibition of PU.1 levels. This was accompanied by inhibition of proliferation and restoration in the ability of the proerythroblastic cells to produce hemoglobin, i.e., reversion of the leukemic phenotype. The data suggest that overexpression of PU.1 gene is the immediate cause for maintaining the leukemic phenotype of the disease by retaining the self-renewal capacity of transformed erythroblastic cells and by blocking the terminal differentiation program towards erythrocytes.

  13. Pu-238 fuel form activities, January 1-31, 1982

    SciTech Connect

    Not Available

    1982-03-01

    This monthly report for /sup 238/Pu fuel form activities has two main sections: SRP-PuFF facility and SRL fuel form activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.

  14. Pu-238 fuel form activities, January 1-31, 1981

    SciTech Connect

    Not Available

    1981-02-01

    This monthly report for /sup 238/Pu Fuel Form Activities has two main sections: SRP-PuFF facility and SRL Fuel Form Activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.

  15. Pu-238 fuel form activities, January 1-31, 1983

    SciTech Connect

    Not Available

    1983-03-01

    This monthly report for /sup 238/Pu Fuel Form Activities has two main sections: SRP-PuFF facility and SRL Fuel Form Activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.

  16. Fission xenon from extinct Pu-244 in 14,301.

    NASA Technical Reports Server (NTRS)

    Drozd, R.; Hohenberg, C. M.; Ragan, D.

    1972-01-01

    Xenon extracted in step-wise heating of lunar breccia 14,301 contains a fission-like component in excess of that attributable to uranium decay during the age of the solar system. There seems to be no adequate source for this component other than Pu-244. Verification that this component is in fact due to the spontaneous fission of extinct Pu-244 comes from the derived spectrum which is similar to that observed from artificially produced Pu-244. It thus appears that Pu-244 was extant at the time lunar crustal material cooled sufficiently to arrest the thermal diffusion of xenon. Subsequent history has apparently maintained the isotopic integrity of plutonium fission xenon. Of major importance are details of the storage itself. Either the fission component is the result of in situ fission of Pu-244 and subsequent storage in 14,301 material, or the fission xenon was stored in an intermediate reservoir before incorporation into 14,301.

  17. Sputtering yield of Pu bombarded by fission Fragments from Cf

    SciTech Connect

    Danagoulian, Areg; Klein, Andreas; Mcneil, Wendy V; Yuan, Vincent W

    2008-01-01

    We present results on the yield of sputtering of Pu atoms from a Pu foil, bombarded by fission fragments from a {sup 252}Cf source in transmission geometry. We have found the number of Pu atoms/incoming fission fragments ejected to be 63 {+-} 1. In addition, we show measurements of the sputtering yield as a function of distance from the central axis, which can be understood as an angular distribution of the yield. The results are quite surprising in light of the fact that the Pu foil is several times the thickness of the range of fission fragment particles in Pu. This indicates that models like the binary collision model are not sufficient to explain this behavior.

  18. Spatial distribution of (241)Am, (137)Cs, (238)Pu, (239,240)Pu and (241)Pu over 17 year periods in the Ravenglass saltmarsh, Cumbria, UK.

    PubMed

    Oh, J-S; Warwick, P E; Croudace, I W

    2009-01-01

    Ninety five surface scrape samples were collected at the Ravenglass saltmarsh and analysed for radionuclides by alpha spectrometry ((238)Pu and (239,240)Pu), gamma spectrometry ((241)Am and (137)Cs) and liquid scintillation counting ((241)Pu). Both (241)Am and (137)Cs activities are compared with those reported by Horrill [1983. Concentrations and spatial distribution of radioactivity in an ungrazed saltmarsh. In: Coughtrey, P.J. (Ed.), Ecological Aspects of Radionuclide Release. British Ecological Society Special Publication No. 3. Blackwell, Oxford, pp. 119-215.] Significant decreases in activities for both radionuclides were observed which is caused by the declining levels of discharges from the Sellafield nuclear reprocessing plant since the 1980s. It has been concluded that the spatial distribution of these radionuclides are controlled by the tidal currents and the clay contents in the sediments. There is evidence of surface erosion of the saltmarsh and redistribution of radionuclides in the saltmarsh using isotopic ratios of measured Pu.

  19. Spatial distribution of (241)Am, (137)Cs, (238)Pu, (239,240)Pu and (241)Pu over 17 year periods in the Ravenglass saltmarsh, Cumbria, UK.

    PubMed

    Oh, J-S; Warwick, P E; Croudace, I W

    2009-01-01

    Ninety five surface scrape samples were collected at the Ravenglass saltmarsh and analysed for radionuclides by alpha spectrometry ((238)Pu and (239,240)Pu), gamma spectrometry ((241)Am and (137)Cs) and liquid scintillation counting ((241)Pu). Both (241)Am and (137)Cs activities are compared with those reported by Horrill [1983. Concentrations and spatial distribution of radioactivity in an ungrazed saltmarsh. In: Coughtrey, P.J. (Ed.), Ecological Aspects of Radionuclide Release. British Ecological Society Special Publication No. 3. Blackwell, Oxford, pp. 119-215.] Significant decreases in activities for both radionuclides were observed which is caused by the declining levels of discharges from the Sellafield nuclear reprocessing plant since the 1980s. It has been concluded that the spatial distribution of these radionuclides are controlled by the tidal currents and the clay contents in the sediments. There is evidence of surface erosion of the saltmarsh and redistribution of radionuclides in the saltmarsh using isotopic ratios of measured Pu. PMID:19285416

  20. Resolving global versus local/regional Pu sources in the environment using sector ICP-MS

    USGS Publications Warehouse

    Ketterer, M.E.; Hafer, K.M.; Link, C.L.; Kolwaite, D.; Wilson, Jim; Mietelski, J.W.

    2004-01-01

    Sector inductively coupled plasma mass spectrometry is a versatile method for the determination of plutonium activities and isotopic compositions in samples containing this element at fallout levels. Typical detection limits for 239+240Pu are 0.1, 0.02 and 0.002 Bq kg -1Pu for samples sizes of 0.5 g, 3 g, and 50 g of soil, respectively. The application of sector ICP-MS-based Pu determinations is demonstrated in studies in sediment chronology, soil Pu inventory and depth distribution, and the provenance of global fallout versus local or regional Pu sources. A sediment core collected from Sloans Lake (Denver, Colorado, USA) exhibits very similar 137Cs and 239+240Pu activity profiles; 240Pu/239Pu atom ratios indicate possible small influences from the Nevada Test Site and/or the Rocky Flats Environmental Technology Site. An undisturbed soil profile from Lockett Meadow (Flagstaff, Arizona, USA) exhibits an exponential decrease in 239+240Pu activity versus depth; 240Pu/239Pu in the top 3 cm is slightly lower than the global fallout range of 0.180 ?? 0.014 due to possible regional influence of Nevada Test Site fallout. The 239??240Pu inventory at Lockett Meadow is 56 ?? 4 Bq m-2, consistent with Northern Hemisphere mid-latitude fallout. Archived NdF3 sources, prepared from Polish soils, demonstrate that substantial 239+240Pu from the 1986 Chernobyl disaster has been deposited in north eastern regions of Poland; compared to global fallout, Chernobyl Pu exhibits higher abundances of 240Pu and 241Pu. The ratios 240Pu/239pu and 241Pu/239Pu co-vary and range from 0.186-0.348 and 0.0029-0.0412, respectively, in forest soils (241Pu/239Pu = 0.2407??[240Pu/239Pu] - 0.0413; r2 = 0.9924). ?? The Royal Society of Chemistry 2004.

  1. Critical issues with the in vivo comet assay: A report of the comet assay working group in the 6th International Workshop on Genotoxicity Testing (IWGT).

    PubMed

    Speit, Günter; Kojima, Hajime; Burlinson, Brian; Collins, Andrew R; Kasper, Peter; Plappert-Helbig, Ulla; Uno, Yoshifumi; Vasquez, Marie; Beevers, Carol; De Boeck, Marlies; Escobar, Patricia A; Kitamoto, Sachiko; Pant, Kamala; Pfuhler, Stefan; Tanaka, Jin; Levy, Dan D

    2015-05-01

    As a part of the 6th IWGT, an expert working group on the comet assay evaluated critical topics related to the use of the in vivo comet assay in regulatory genotoxicity testing. The areas covered were: identification of the domain of applicability and regulatory acceptance, identification of critical parameters of the protocol and attempts to standardize the assay, experience with combination and integration with other in vivo studies, demonstration of laboratory proficiency, sensitivity and power of the protocol used, use of different tissues, freezing of samples, and choice of appropriate measures of cytotoxicity. The standard protocol detects various types of DNA lesions but it does not detect all types of DNA damage. Modifications of the standard protocol may be used to detect additional types of specific DNA damage (e.g., cross-links, bulky adducts, oxidized bases). In addition, the working group identified critical parameters that should be carefully controlled and described in detail in every published study protocol. In vivo comet assay results are more reliable if they were obtained in laboratories that have demonstrated proficiency. This includes demonstration of adequate response to vehicle controls and an adequate response to a positive control for each tissue being examined. There was a general agreement that freezing of samples is an option but more data are needed in order to establish generally accepted protocols. With regard to tissue toxicity, the working group concluded that cytotoxicity could be a confounder of comet results. It is recommended to look at multiple parameters such as histopathological observations, organ-specific clinical chemistry as well as indicators of tissue inflammation to decide whether compound-specific toxicity might influence the result. The expert working group concluded that the alkaline in vivo comet assay is a mature test for the evaluation of genotoxicity and can be recommended to regulatory agencies for use. PMID

  2. Fetal Sex Determination using Non-Invasive Method of Cell-free Fetal DNA in Maternal Plasma of Pregnant Women During 6(th)- 10(th) Weeks of Gestation.

    PubMed

    Zargari, Maryam; Sadeghi, Mohammad Reza; Shahhosseiny, Mohammad Hassan; Kamali, Koroush; Saliminejad, Kyomars; Esmaeilzadeh, Ali; Khorshid, Hamid Reza Khorram

    2011-10-01

    In previous years, identification of fetal cells in maternal blood circulation has caused a new revolution in non-invasive method of prenatal diagnosis. Low number of fetal cells in maternal blood and long-term survival after pregnancy limited the use of fetal cells in diagnostic and clinical applications. With the discovery of cell-free fetal DNA (cffDNA) in plasma of pregnant women, access to genetic material of the fetus had become possible to determine early gender of a fetus in pregnancies at the risk of X-linked genetic conditions instead of applying invasive methods. Therefore in this study, the probability of detecting sequences on the Y chromosome in pregnant women has been evaluated to identify the gender of fetuses. Peripheral blood samples were obtained from 80 pregnant women at 6(th) to 10(th) weeks of gestation and then the fetal DNA was extracted from the plasma. Nested PCR was applied to detect the sequences of single copy SRY gene and multi copy DYS14 & DAZ genes on the Y chromosome of the male fetuses. At the end, all the obtained results were compared with the actual gender of the newborns. In 40 out of 42 born baby boys, the relevant gene sequences were identified and 95.2% sensitivity was obtained. Non-invasive early determination of fetal gender using cffDNA could be employed as a pre-test in the shortest possible time and with a high reliability to avoid applying invasive methods in cases where a fetus is at the risk of genetic diseases.

  3. Critical issues with the in vivo comet assay: A report of the comet assay working group in the 6th International Workshop on Genotoxicity Testing (IWGT).

    PubMed

    Speit, Günter; Kojima, Hajime; Burlinson, Brian; Collins, Andrew R; Kasper, Peter; Plappert-Helbig, Ulla; Uno, Yoshifumi; Vasquez, Marie; Beevers, Carol; De Boeck, Marlies; Escobar, Patricia A; Kitamoto, Sachiko; Pant, Kamala; Pfuhler, Stefan; Tanaka, Jin; Levy, Dan D

    2015-05-01

    As a part of the 6th IWGT, an expert working group on the comet assay evaluated critical topics related to the use of the in vivo comet assay in regulatory genotoxicity testing. The areas covered were: identification of the domain of applicability and regulatory acceptance, identification of critical parameters of the protocol and attempts to standardize the assay, experience with combination and integration with other in vivo studies, demonstration of laboratory proficiency, sensitivity and power of the protocol used, use of different tissues, freezing of samples, and choice of appropriate measures of cytotoxicity. The standard protocol detects various types of DNA lesions but it does not detect all types of DNA damage. Modifications of the standard protocol may be used to detect additional types of specific DNA damage (e.g., cross-links, bulky adducts, oxidized bases). In addition, the working group identified critical parameters that should be carefully controlled and described in detail in every published study protocol. In vivo comet assay results are more reliable if they were obtained in laboratories that have demonstrated proficiency. This includes demonstration of adequate response to vehicle controls and an adequate response to a positive control for each tissue being examined. There was a general agreement that freezing of samples is an option but more data are needed in order to establish generally accepted protocols. With regard to tissue toxicity, the working group concluded that cytotoxicity could be a confounder of comet results. It is recommended to look at multiple parameters such as histopathological observations, organ-specific clinical chemistry as well as indicators of tissue inflammation to decide whether compound-specific toxicity might influence the result. The expert working group concluded that the alkaline in vivo comet assay is a mature test for the evaluation of genotoxicity and can be recommended to regulatory agencies for use.

  4. Performance of Cladding on MOX Fuel with Low 240Pu/239Pu Ratio

    SciTech Connect

    McCoy, Kevin; Blanpain, Patrick; Morris, Robert Noel

    2014-01-01

    The U.S. Department of Energy has decided to dispose of a portion of its surplus plutonium by reconstituting it into mixed oxide (MOX) fuel and irradiating it in commercial power reactors. As part of fuel qualification, four lead assemblies were manufactured and irradiated to a maximum fuel rod average burnup of 47.3 MWd/kg heavy metal. This was the world s first commercial irradiation of MOX fuel with a 240Pu/239Pu ratio less than 0.10. Five fuel rods with varying burnups and plutonium contents were selected from one of the assemblies and shipped to Oak Ridge National Laboratory for hot cell examination. This paper discusses the results of those examinations with emphasis on cladding performance. Exams relevant to the cladding included visual and eddy current exams, profilometry, microscopy, hydrogen analysis, gallium analysis, and mechanical testing. There was no discernible effect of the type of MOX fuel on the performance of the cladding.

  5. Distinguishing Pu Metal from Pu Oxide and Determining alpha-ratio using Fast Neutron Counting

    SciTech Connect

    Verbeke, J. M.; Chapline, G. F.; Nakae, L. F.; Prasad, M. K.; Sheets, S. A.; Snyderman, N. J.

    2015-01-07

    We describe a new method for determining the ratio of the rate of (α, n) source neutrons to the rate of spontaneous fission neutrons, the so called α-ratio. This method is made possible by fast neutron counting with liquid scintillator detectors, which can determine the shape of the fast neutron spectrum. The method utilizes the spectral difference between fission spectrum neutrons from Pu metal and the spectrum of (α, n) neutrons from PuO2. Our method is a generalization of the Cifarelli-Hage method for determining keff for fissile assemblies, and also simultaneously determines keff along with the α-ratio.

  6. Internal Corrosion Analysis of Model 9975 Packaging Containing Pu or PuO{sub 2} During Shipping and Storage

    SciTech Connect

    Vormelker, P.

    1999-03-23

    The Materials Consultation Group of SRTC has completed an internal corrosion analysis of the Model 9975 packaging assembly containing either Pu or PuO2 for storage in K Reactor under ambient conditions for a period of 12 years. The 12-year storage period includes two years for shipping and up to ten years for storage.

  7. Oxidation states, geometries, and electronic structures of plutonium tetroxide PuO4 isomers: is octavalent Pu viable?

    PubMed

    Huang, Wei; Xu, Wen-Hua; Su, Jing; Schwarz, W H E; Li, Jun

    2013-12-16

    In neutral chemical compounds, the highest known oxidation state of all elements in the Periodic Table is +VIII. While PuO4 is viewed as an exotic Pu(+VIII) complex, we have shown here that no stable electronic homologue of octavalent RuO4 and OsO4 exists for PuO4, even though Pu has the same number of eight valence electrons as Ru and Os. Using quantum chemical approaches at the levels of quasi-relativistic DFT, MP2, CCSD(T), and CASPT2, we find the ground state of PuO4 as a quintet (5)C2v-(PuO2)(+)(O2)(-) complex with the leading valence configuration of an (f(3))plutonyl(V) unit, loosely coupled to a superoxido (π*(3))O2(-) ligand. This stable isomer is likely detectable as a transient species, while the previously suggested planar (1)D4h-Pu(VIII)O4 isomer is only metastable. Through electronic structure analyses, the bonding and the oxidation states are explained and rationalized. We have predicted the characteristics of the electronic and vibrational spectra to assist future experimental identification of (PuO2)(+)(O2)(-) by IR, UV-vis, and ionization spectroscopy.

  8. Oxidation states, geometries, and electronic structures of plutonium tetroxide PuO4 isomers: is octavalent Pu viable?

    PubMed

    Huang, Wei; Xu, Wen-Hua; Su, Jing; Schwarz, W H E; Li, Jun

    2013-12-16

    In neutral chemical compounds, the highest known oxidation state of all elements in the Periodic Table is +VIII. While PuO4 is viewed as an exotic Pu(+VIII) complex, we have shown here that no stable electronic homologue of octavalent RuO4 and OsO4 exists for PuO4, even though Pu has the same number of eight valence electrons as Ru and Os. Using quantum chemical approaches at the levels of quasi-relativistic DFT, MP2, CCSD(T), and CASPT2, we find the ground state of PuO4 as a quintet (5)C2v-(PuO2)(+)(O2)(-) complex with the leading valence configuration of an (f(3))plutonyl(V) unit, loosely coupled to a superoxido (π*(3))O2(-) ligand. This stable isomer is likely detectable as a transient species, while the previously suggested planar (1)D4h-Pu(VIII)O4 isomer is only metastable. Through electronic structure analyses, the bonding and the oxidation states are explained and rationalized. We have predicted the characteristics of the electronic and vibrational spectra to assist future experimental identification of (PuO2)(+)(O2)(-) by IR, UV-vis, and ionization spectroscopy. PMID:24274785

  9. Preparation of Pu{sup 239} sources

    SciTech Connect

    Holcomb, H.P.

    1988-08-05

    The Separations Technology Laboratory has prepared four sources to be used for calibrating a waste assay system (Passive/Active Neutron Assay) in Building 724-8G (Burial Ground). The four sources contain 0.5, 0.1, 0.05, and 0.01 grams Pu{sup 239}, respectively. The sources were prepared using aliquots from a single solution provided by the Quality Control (QC) group of Laboratories Department. The solution contained weapons-grade plutonium dissolved in nitric acid. Final solution acidity was 3M. Coulometry had been used to obtain a total plutonium content per unit volume. The weight percent of the plutonium isotopes present was obtained via mass spectrometry.

  10. LLNL Workshop on TEM of Pu

    SciTech Connect

    King, W.E.

    1996-09-10

    On Sept. 10, 1996, LLNL hosted a workshop aimed at answering the question: Is it possible to carry out transmission electron microscopy (TEM) on plutonium metal in an electron microscope located outside the LLNL plutonium facility. The workshop focused on evaluation of a proposed plan for Pu microscopy both from a technical and environment, health, and safety point of view. After review and modification of the plan, workshop participants unanimously concluded that: (1) the technical plan is sound, (2) this technical plan, including a proposal for a new TEM, provides significant improvements and unique capabilities compared with the effort at LANL and is therefore complementary, (3) there is no significant environment, health, and safety obstacle to this plan.

  11. Microscopic Calculations of 240Pu Fission

    SciTech Connect

    Younes, W; Gogny, D

    2007-09-11

    Hartree-Fock-Bogoliubov calculations have been performed with the Gogny finite-range effective interaction for {sup 240}Pu out to scission, using a new code developed at LLNL. A first set of calculations was performed with constrained quadrupole moment along the path of most probable fission, assuming axial symmetry but allowing for the spontaneous breaking of reflection symmetry of the nucleus. At a quadrupole moment of 345 b, the nucleus was found to spontaneously scission into two fragments. A second set of calculations, with all nuclear moments up to hexadecapole constrained, was performed to approach the scission configuration in a controlled manner. Calculated energies, moments, and representative plots of the total nuclear density are shown. The present calculations serve as a proof-of-principle, a blueprint, and starting-point solutions for a planned series of more comprehensive calculations to map out a large set of scission configurations, and the associated fission-fragment properties.

  12. Air concentrations of 239Pu and 240Pu and potential radiation doses to persons living near Pu-contaminated areas in Palomares, Spain.

    PubMed

    Iranzo, E; Salvador, S; Iranzo, C E

    1987-04-01

    On 17 January 1966, an accident during a refueling operation resulted in the destruction of an air force KC-135 tanker and a B-52 bomber carrying four thermonuclear weapons. Two weapons, whose parachutes opened, were found intact. The others experienced non-nuclear explosion with some burning and release of the fissile fuel at impact. Joint efforts by the United States and Spain resulted in remedial action and a long-term program to monitor the effectiveness of the cleanup. Air concentrations of 239Pu and 240Pu have been continuously monitored since the accident. The average annual air concentration for each location was used to estimate committed dose equivalents for individuals living and working around the air sampling stations. The average annual 239Pu and 240Pu air concentrations during the 15-y period corresponding to 1966-1980 and the potential committed dose equivalents for various tissues due to the inhalation of the 239Pu and 240Pu average annual air concentration during this period are shown and discussed in the report.

  13. Air concentrations of /sup 239/Pu and /sup 240/Pu and potential radiation doses to persons living near Pu-contaminated areas in Palomares, Spain

    SciTech Connect

    Iranzo, E.; Salvador, S.; Iranzo, C.E.

    1987-04-01

    On 17 January 1966, an accident during a refueling operation resulted in the destruction of an air force KC-135 tanker and a B-52 bomber carrying four thermonuclear weapons. Two weapons, whose parachutes opened, were found intact. The others experienced non-nuclear explosion with some burning and release of the fissile fuel at impact. Joint efforts by the United States and Spain resulted in remedial action and a long-term program to monitor the effectiveness of the cleanup. Air concentrations of /sup 239/Pu and /sup 240/Pu have been continuously monitored since the accident. The average annual air concentration for each location was used to estimate committed dose equivalents for individuals living and working around the air sampling stations. The average annual /sup 239/Pu and /sup 240/Pu air concentrations during the 15-y period corresponding to 1966-1980 and the potential committed dose equivalents for various tissues due to the inhalation of the /sup 239/Pu and /sup 240/Pu average annual air concentration during this period are shown and discussed in the report.

  14. Air concentrations of 239Pu and 240Pu and potential radiation doses to persons living near Pu-contaminated areas in Palomares, Spain.

    PubMed

    Iranzo, E; Salvador, S; Iranzo, C E

    1987-04-01

    On 17 January 1966, an accident during a refueling operation resulted in the destruction of an air force KC-135 tanker and a B-52 bomber carrying four thermonuclear weapons. Two weapons, whose parachutes opened, were found intact. The others experienced non-nuclear explosion with some burning and release of the fissile fuel at impact. Joint efforts by the United States and Spain resulted in remedial action and a long-term program to monitor the effectiveness of the cleanup. Air concentrations of 239Pu and 240Pu have been continuously monitored since the accident. The average annual air concentration for each location was used to estimate committed dose equivalents for individuals living and working around the air sampling stations. The average annual 239Pu and 240Pu air concentrations during the 15-y period corresponding to 1966-1980 and the potential committed dose equivalents for various tissues due to the inhalation of the 239Pu and 240Pu average annual air concentration during this period are shown and discussed in the report. PMID:3570788

  15. Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint U.S./ Russian Progress Report for Fiscal Year 1997, Volume 4, Part 8 - Neutron Poison Plates in Assemblies Containing Homogeneous Mixtures of Polystyrene-Moderated Plutonium and Uranium Oxides

    SciTech Connect

    Yavuz, M.

    1999-05-01

    In the 1970s at the Battelle Pacific Northwest Laboratory (PNL), a series of critical experiments using a remotely operated Split-Table Machine was performed with homogeneous mixtures of (Pu-U)O{sub 2}-polystyrene fuels in the form of square compacts having different heights. The experiments determined the critical geometric configurations of MOX fuel assemblies with and without neutron poison plates. With respect to PuO{sub 2} content and moderation [H/(Pu+U)atomic] ratio (MR), two different homogeneous (Pu-U) O{sub 2}-polystyrene mixtures were considered: Mixture (1) 14.62 wt% PuO{sub 2} with 30.6 MR, and Mixture (2) 30.3 wt% PuO{sub 2} with 2.8 MR. In all mixtures, the uranium was depleted to about O.151 wt% U{sup 235}. Assemblies contained copper, copper-cadmium or aluminum neutron poison plates having thicknesses up to {approximately}2.5 cm. This evaluation contains 22 experiments for Mixture 1, and 10 for Mixture 2 compacts. For Mixture 1, there are 10 configurations with copper plates, 6 with aluminum, and 5 with copper-cadmium. One experiment contained no poison plate. For Mixture 2 compacts, there are 3 configurations with copper, 3 with aluminum, and 3 with copper-cadmium poison plates. One experiment contained no poison plate.

  16. How Do 4th, 5th, and 6th Grade Students' Categories of Cognitive Reflections in Interviews on Derivational Morphology Compare to Their Upper Level Spelling Inventory Orthographic Knowledge?

    ERIC Educational Resources Information Center

    Smith, Darcie D.

    2012-01-01

    Eighty-seven 4th, 5th and 6th grade students were administered the "Derivational Relatedness Interview" (DRI) (Templeton, Smith, Moloney, Van Pelt, & Ives, 2009). The purpose of this instrument is to explore students' understanding of derivational morphology. During the same week, the subjects were also administered an Upper…

  17. Study of the Effects on Student Knowledge and Perceptions of Activities Related to Submetering the 6th Grade Wing of a Middle School, to Displaying the Carbon Footprint, and to Efforts to Reduce Energy Consumption and Greenhouse Gases

    ERIC Educational Resources Information Center

    Peck, Rick

    2009-01-01

    The purpose of the study was to determine the effects upon student knowledge and perceptions regarding greenhouse gas emissions as a result of an intervention relying upon the submetering the 6th grade wing of a Middle School, displaying the information regarding electrical consumption and carbon footprint, and reducing the electrical consumption…

  18. EVI1 Impairs myelopoiesis by deregulation of PU.1 function.

    PubMed

    Laricchia-Robbio, Leopoldo; Premanand, Kavitha; Rinaldi, Ciro R; Nucifora, Giuseppina

    2009-02-15

    EVI1 is an oncogene inappropriately expressed in the bone marrow (BM) of approximately 10% of myelodysplastic syndrome (MDS) patients. This disease is characterized by severe anemia and multilineage myeloid dysplasia that are thought to be a major cause of mortality in MDS patients. We earlier reported on a mouse model that constitutive expression of EVI1 in the BM led to fatal anemia and myeloid dysplasia, as observed in MDS patients, and we subsequently showed that EVI1 interaction with GATA1 blocks proper erythropoiesis. Whereas this interaction could provide the basis for the erythroid defects in EVI1-positive MDS, it does not explain the alteration of myeloid differentiation. Here, we have examined the expression of several genes activated during terminal myelopoiesis in BM cells and identified a group of them that are altered by EVI1. A common feature of these genes is their regulation by the transcription factor PU.1. We report here that EVI1 interacts with PU.1 and represses the PU.1-dependent activation of a myeloid promoter. EVI1 does not seem to inhibit PU.1 binding to DNA, but rather to block its association with the coactivator c-Jun. After mapping the PU.1-EVI1 interaction sites, we show that an EVI1 point mutant, unable to bind PU.1, restores the activation of PU.1-regulated genes and allows a normal differentiation of BM progenitors in vitro.

  19. Electronic Structure, Localization and 5f Occupancy in Pu Materials

    SciTech Connect

    Joyce, John J.; Beaux, Miles F.; Durakiewicz, Tomasz; Graham, Kevin S.; Bauer, Eric D.; Mitchell, Jeremy N.; Tobash, Paul H.; Richmond, Scott

    2012-05-03

    The electronic structure of delta plutonium ({delta}-Pu) and plutonium compounds is investigated using photoelectron spectroscopy (PES). Results for {delta}-Pu show a small component of the valence electronic structure which might reasonably be associated with a 5f{sup 6} configuration. PES results for PuTe are used as an indication for the 5f{sup 6} configuration due to the presence of atomic multiplet structure. Temperature dependent PES data on {delta}-Pu indicate a narrow peak centered 20 meV below the Fermi energy and 100 meV wide. The first PES data for PuCoIn5 indicate a 5f electronic structure more localized than the 5fs in the closely related PuCoGa{sub 5}. There is support from the PES data for a description of Pu materials with an electronic configuration of 5f{sup 5} with some admixture of 5f{sup 6} as well as a localized/delocalized 5f{sup 5} description.

  20. Measurement of the 242Pu neutron capture cross section

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Chyzh, A.; Dance Collaboration

    2015-10-01

    Precision (n,f) and (n, γ) cross sections are important for the network calculations of the radiochemical diagnostic chain for the U.S. DOE's Stockpile Stewardship Program. 242Pu(n, γ) cross section is relevant to the network calculations of Pu and Am. Additionally, new reactor concepts have catalyzed considerable interest in the measurement of improved cross sections for neutron-induced reactions on key actinides. To date, little or no experimental data has been reported on 242Pu(n, γ) for incident neutron energy below 50 keV. A new measurement of the 242Pu(n, γ) reaction was performed with the DANCE together with an improved PPAC for fission-fragment detection at LANSCE during FY14. The relative scale of the 242Pu(n, γ) cross section spans four orders of magnitude for incident neutron energies from thermal to ~ 30 keV. The absolute scale of the 242Pu(n, γ) cross section is set according to the measured 239Pu(n,f) resonance at 7.8 eV; the target was spiked with 239Pu for this measurement. The absolute 242Pu(n, γ) neutron capture cross section is ~ 30% higher than the cross section reported in ENDF for the 2.7 eV resonance. Latest results to be reported. Funded by U.S. DOE Contract No. DE-AC52-07NA27344 (LLNL) and DE-AC52-06NA25396 (LANL). U.S. DOE/NNSA Office of Defense Nuclear Nonproliferation Research and Development. Isotopes (ORNL).

  1. EDITORIAL: The 6th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications (PowerMEMS 2006)

    NASA Astrophysics Data System (ADS)

    Fréchette, Luc G.

    2007-09-01

    Energy is a sector of paramount importance over the coming decades if we are to ensure sustainable development that respects our environment. The research and development of novel approaches to convert available energy into usable forms using micro and nanotechnologies can contribute towards this goal and meet the growing need for power in small scale portable applications. The dominant power sources for handheld and other portable electronics are currently primary and rechargeable batteries. Their limited energy density and adverse effects on the environment upon disposal suggest that alternative approaches need to be explored. This special issue will showcase some of the leading work in this area, initially presented at PowerMEMS 2006, the 6th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications. Power MEMS are defined as microsystems for electrical power generation and other energy conversion applications, including propulsion and cooling. The range of power MEMS technologies includes micro thermodynamic machines, such as microturbines, miniature internal combustion engines and micro-coolers; solid-state direct energy conversion, such as thermoelectric and photovoltaic microstructures; micro electrochemical devices, such as micro fuel cells and nanostructure batteries; vibration energy harvesting devices, such as piezoelectric, magnetic or electrostatic micro generators, as well as micro thrusters and rocket engines for propulsion. These can either be driven by scavenging thermal, mechanical or solar energy from the environment, or from a stored energy source, such as chemical fuel or radioactive material. The unique scope leads to unique challenges in the development of power MEMS, ranging from the integration of novel materials to the efficient small scale implementation of energy conversion principles. In this special issue, Mitcheson et al provide a comparative assessment of three inertial vibration

  2. Elastic properties of gamma-Pu by resonant ultrasound spectroscopy

    SciTech Connect

    Migliori, Albert; Betts, J; Trugman, A; Mielke, C H; Mitchell, J N; Ramos, M; Stroe, I

    2009-01-01

    Despite intense experimental and theoretical work on Pu, there is still little understanding of the strange properties of this metal. We used resonant ultrasound spectroscopy method to investigate the elastic properties of pure polycrystalline Pu at high temperatures. Shear and longitudinal elastic moduli of the {gamma}-phase of Pu were determined simultaneously and the bulk modulus was computed from them. A smooth linear and large decrease of all elastic moduli with increasing temperature was observed. We calculated the Poisson ratio and found that it increases from 0.242 at 519K to 0.252 at 571K.

  3. 239Pu Resonance Evaluation for Thermal Benchmark System Calculations

    NASA Astrophysics Data System (ADS)

    Leal, L. C.; Noguere, G.; de Saint Jean, C.; Kahler, A. C.

    2014-04-01

    Analyses of thermal plutonium solution critical benchmark systems have indicated a deficiency in the 239Pu resonance evaluation. To investigate possible solutions to this issue, the Organisation for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) Working Party for Evaluation Cooperation (WPEC) established Subgroup 34 to focus on the reevaluation of the 239Pu resolved resonance parameters. In addition, the impacts of the prompt neutron multiplicity (νbar) and the prompt neutron fission spectrum (PFNS) have been investigated. The objective of this paper is to present the results of the 239Pu resolved resonance evaluation effort.

  4. PU IMMOBILIZATION - INDUCTION MELTING ND OFFGAS TESTING

    SciTech Connect

    Marra, J

    2006-11-28

    The Cylindrical Induction Melter (CIM) at the Aiken County Technology Laboratory (ACTL) has been operated by the Savannah River National Laboratory (SRNL) to support the Pu Disposition Conceptual Design (CD-0) development effort. The primary purpose of this report is to summarize the offgas sampling tests conducted in the CIM to capture and analyze the particulate and vapors emitted from lanthanide borosilicate (LaBS) Frit X with HfO{sub 2} as a surrogate for PuO{sub 2} and added impurities. In addition, this report describes several initial tests of the CIM for the vitrification of LaBS Frit X with HfO{sub 2}. The activities required to produce Frit X from batch chemical oxides for subsequent milling to yield glass frit of nominally 20 micron particle size are also discussed. The tests with impurities added showed that alkali salts such as NaCl and KCl were substantially emitted into the offgas system as the salt particulate, HCl, or Cl{sub 2}. Retention of Na and K in the glass were about 80 and 55%, respectively. Chloride retention was about 35%; chloride remaining in the glass was 0.29-0.37 wt%. Based on a material balance, approximately 83% of F fed was retained in the glass at about 0.09 wt % (F could not be measured directly at this concentration). Transition metals (Ni, Cu, Fe, Mo, Cr) were also volatilized to varying extents. A very small amount (<0.1 g) of nickel compounds and KCl were found in crystals deposited on the melter offgas line. Overall, about 58-72% of the impurities added were volatilized. Virtually all of the particulate species were collected on the nominal 0.3 {micro}m filter. The particulate evolution rate ranged from 2-8 g/kg glass/h. The particulate was found to be as small as 0.2 {micro}m and have an approximate median size of 0.5 {micro}m. The particulate salt was also found to stick together by forming bridges between particles. Further runs without washable salts are recommended. Measurements of particle size distribution for use in

  5. On the electronic configuration in Pu: spectroscopy and theory

    SciTech Connect

    Tobin, J G; Soderlind, P; Landa, A; Moore, K T; Schwartz, A J; Chung, B W; Wall, M; Wills, J M; Eriksson, O; Haire, R; Kutepov, A L

    2006-10-11

    Photoelectron spectroscopy, synchrotron-radiation-based x-ray absorption, electron energy-loss spectroscopy, and density-functional calculations within the mixed-level and magnetic models, together with canonical band theory have been used to study the electron configuration in Pu. These methods suggest a 5f{sup n} configuration for Pu of 5 {le} n < 6, with n {ne} 6, contrary to what has recently been suggested in several publications. We show that the n = 6 picture is inconsistent with the usual interpretation of photoemission and x-ray absorption spectra. Instead, these spectra support the traditional conjecture of a 5f{sup 5} configuration in Pu as is obtained by density-functional theory. We further argue, based on 5f-band filling, that an n = 6 hypothesis is incompatible with the position of Pu in the actinide series and its monoclinic ground-state phase.

  6. Neutron Capture and Fission Measurement on ^238Pu at DANCE

    NASA Astrophysics Data System (ADS)

    Chyzh, Andrii; Wu, Ching-Yen; Kwan, Elaine; Henderson, Roger; Gostic, Jolie; Couture, Aaron; Young, Hye; Ullmann, John; O'Donnell, John; Jandel, Marian; Haight, Robert; Bredeweg, Todd

    2012-10-01

    Neutron capture and fission reactions on actinides are important in nuclear engineering and physics. DANCE (Detector for Advanced Neutron Capture Measurement, LANL) combined with PPAC (avalanche technique based fission tagging detector, LLNL) were used to study the neutron capture reactions in ^238Pu. Because of extreme spontaneous α-radioactivity in ^238Pu and associated safety issues, 3 separate experiments were performed in 2010-2012. The 1st measurement was done without fission tagging on a 396-μg thick target. The 2nd one was with PPAC on the same target. The 3rd final measurement was done on a thin target with a mass of 40 μg in order to reduce α-background load on PPAC. This was the first such measurement in a laboratory environment. The absolute ^238Pu(n,γ) cross section is presented together with the prompt γ-ray multiplicity in the ^238Pu(n,f) reaction.

  7. [239Pu and chromosomal aberrations in human peripheral blood lymphocytes].

    PubMed

    Okladnikova, N D; Osovets, S V; Kudriavtseva, T I

    2009-01-01

    The genome status in somatic cells was assessed using the chromosomal aberration (CA) test in peripheral blood lymphocytes from 194 plutonium workers exposed to occupational radiation mainly from low-transportable compounds of airborne 230Pu. Pu body burden at the time of cytogenetic study varied from values close to the method sensitivity to values multiply exceeding the permissible level. Standard (routine) methods of peripheral blood lymphocytes cultivation were applied. Chromatid- and chromosomal-type structural changes were estimated. Aberrations were estimated per 100 examined metaphase cells. The quantitative relationship between the CA frequency and Pu body burden and the absorbed dose to the lung was found. Mathematical processing of results was carried out based on the phenomenological model. The results were shown as theoretical and experimental curves. The threshold of the CA yield was 0.43 +/- 0.03 kBq (Pu body burden) and 6.12 +/- 1.20 cGy (absorbed dose to the lung).

  8. [ECG indices in dogs after inhalation of 239Pu].

    PubMed

    Karpova, V N

    1985-11-01

    Dogs of both sexes aged 2 to 4 were subjected to inhalation inoculation with polymer 239Pu or submicron 239PuO2 aerosols in amounts close to acute, subacute and chronically effective ones. ECG was recorded in standard, amplified and single leads (V3). All calculations were done by lead II. Signs of the right heart overburdening were noted in the presence of the P-pulmonale complex, deep S1 wave or cardiac electrical axis of SI-SII-SIII type. Signs of the right heart overburdening were revealed after inhalation of polimer 239Pu (70%). The absence of similar changes in damage caused by 239Pu could be attributed to its fast resorption from the lungs resulting in more moderate lesion of the respiratory organs.

  9. Radiation damage effects in candidate titanates for Pu disposition: Pyrochlore

    NASA Astrophysics Data System (ADS)

    Strachan, D. M.; Scheele, R. D.; Buck, E. C.; Icenhower, J. P.; Kozelisky, A. E.; Sell, R. L.; Elovich, R. J.; Buchmiller, W. C.

    2005-10-01

    Laboratory experiments on titanate ceramics were performed to verify whether certain assumptions are valid regarding the swelling, chemical durability, and microcracking that might occur as 239Pu decays. Titanate ceramics are the material of choice for the immobilization of surplus weapons-grade Pu. The short-lived isotope 238Pu, was incorporated into the ceramic formulation to accelerate the effects of radiation-induced damage. We report on the effects of this damage on the density (volumetric swelling <6%), crystal structure of pyrochlore-bearing specimens (amorphous after about 2 × 1018 α/g), and dissolution (no change from the fully crystalline specimen). Even though the specimens became amorphous during the tests, there was no evidence for microcracking in the photomicrographs from the scanning electron microscope. Thus, although pyrochlore is susceptible to radiation-induced damage, the material remains chemically and physically viable as a material for immobilizing surplus weapons-grade Pu.

  10. Ferro- and antiferro-magnetism in (Np, Pu)BC

    SciTech Connect

    Klimczuk, T.; Kozub, A. L.; Griveau, J.-C.; Colineau, E.; Wastin, F.; Falmbigl, M.; Rogl, P.

    2015-04-01

    Two new transuranium metal boron carbides, NpBC and PuBC, have been synthesized. Rietveld refinements of powder XRD patterns of (Np,Pu)BC confirmed in both cases isotypism with the structure type of UBC. Temperature dependent magnetic susceptibility data reveal antiferromagnetic ordering for PuBC below T{sub N} = 44 K, whereas ferromagnetic ordering was found for NpBC below T{sub C} = 61 K. Heat capacity measurements prove the bulk character of the observed magnetic transition for both compounds. The total energy electronic band structure calculations support formation of the ferromagnetic ground state for NpBC and the antiferromagnetic ground state for PuBC.

  11. Spatial and temporal distribution of Pu in the Northwest Pacific Ocean using modern coral archives.

    PubMed

    Lindahl, Patric; Andersen, Morten B; Keith-Roach, Miranda; Worsfold, Paul; Hyeong, Kiseong; Choi, Min-Seok; Lee, Sang-Hoon

    2012-04-01

    Historical (239)Pu activity concentrations and (240)Pu/(239)Pu atom ratios were determined in skeletons of dated modern corals collected from three locations (Chuuk Lagoon, Ishigaki Island and Iki Island) to identify spatial and temporal variations in Pu inputs to the Northwest Pacific Ocean. The main Pu source in the Northwest Pacific is fallout from atmospheric nuclear weapons testing which consists of global fallout and close-in fallout from the former US Pacific Proving Grounds (PPG) in the Marshall Islands. PPG close-in fallout dominated the Pu input in the 1950s, as was observed with higher (240)Pu/(239)Pu atom ratios (>0.30) at the Ishigaki site. Specific fallout Pu contamination from the Nagasaki atomic bomb and the Ivy Mike thermonuclear detonation at the PPG were identified at Ishigaki Island from the (240)Pu/(239)Pu atom ratios of 0.07 and 0.46, respectively. During the 1960s and 1970s, global fallout was the major Pu source to the Northwest Pacific with over 60% contribution to the total Pu. After the cessation of the atmospheric nuclear tests, the PPG again dominated the Pu input due to the continuous transport of remobilised Pu from the Marshall Islands along the North Equatorial Current and the subsequent Kuroshio Current. The Pu contributions from the PPG in recent coral bands (1984 onwards) varied over time with average estimated PPG contributions between 54% and 72% depending on location.

  12. Method of removing Pu(IV) polymer from nuclear fuel reclaiming liquid

    DOEpatents

    Tallent, Othar K.; Mailen, James C.; Bell, Jimmy T.; Arwood, Phillip C.

    1982-01-01

    A Pu(IV) polymer not extractable from a nuclear fuel reclaiming solution by conventional processes is electrolytically converted to Pu.sup.3+ and PuO.sub.2.sup.2+ ions which are subsequently converted to Pu.sup.4+ ions extractable by the conventional processes.

  13. Spatial and temporal distribution of Pu in the Northwest Pacific Ocean using modern coral archives.

    PubMed

    Lindahl, Patric; Andersen, Morten B; Keith-Roach, Miranda; Worsfold, Paul; Hyeong, Kiseong; Choi, Min-Seok; Lee, Sang-Hoon

    2012-04-01

    Historical (239)Pu activity concentrations and (240)Pu/(239)Pu atom ratios were determined in skeletons of dated modern corals collected from three locations (Chuuk Lagoon, Ishigaki Island and Iki Island) to identify spatial and temporal variations in Pu inputs to the Northwest Pacific Ocean. The main Pu source in the Northwest Pacific is fallout from atmospheric nuclear weapons testing which consists of global fallout and close-in fallout from the former US Pacific Proving Grounds (PPG) in the Marshall Islands. PPG close-in fallout dominated the Pu input in the 1950s, as was observed with higher (240)Pu/(239)Pu atom ratios (>0.30) at the Ishigaki site. Specific fallout Pu contamination from the Nagasaki atomic bomb and the Ivy Mike thermonuclear detonation at the PPG were identified at Ishigaki Island from the (240)Pu/(239)Pu atom ratios of 0.07 and 0.46, respectively. During the 1960s and 1970s, global fallout was the major Pu source to the Northwest Pacific with over 60% contribution to the total Pu. After the cessation of the atmospheric nuclear tests, the PPG again dominated the Pu input due to the continuous transport of remobilised Pu from the Marshall Islands along the North Equatorial Current and the subsequent Kuroshio Current. The Pu contributions from the PPG in recent coral bands (1984 onwards) varied over time with average estimated PPG contributions between 54% and 72% depending on location. PMID:21890207

  14. Probing Actinide Electronic Structure through Pu Cluster Calculations

    DOE PAGES

    Ryzhkov, Mickhail V.; Mirmelstein, Alexei; Yu, Sung-Woo; Chung, Brandon W.; Tobin, James G.

    2013-02-26

    The calculations for the electronic structure of clusters of plutonium have been performed, within the framework of the relativistic discrete-variational method. Moreover, these theoretical results and those calculated earlier for related systems have been compared to spectroscopic data produced in the experimental investigations of bulk systems, including photoelectron spectroscopy. Observation of the changes in the Pu electronic structure as a function of size provides powerful insight for aspects of bulk Pu electronic structure.

  15. First principles calculations on Ga stabilized δ-Pu alloys

    NASA Astrophysics Data System (ADS)

    Hernandez, Sarah C.; Schwartz, Daniel S.; Taylor, Christopher D.; Ray, Asok K.

    2014-03-01

    The high temperature face-centered-cubic phase (δ) of plutonium (Pu) may be stabilized at room temperature with the inclusion of impurities, such as gallium (Ga) or aluminum. The addition of Ga within the δ-phase influences the structural and electronic properties of Pu. Using the full-potential linearized augmented plane-wave density functional theory based method we present a systematic study of bulk Pu-Ga alloys. The goals of these calculations are to understand the evolution of the structural and electronic properties of Ga in a δ-Pu lattice. A 32-atom δ-Pu supercell was used to study Pu-Ga alloys at 3.125, 6.25, and 9.375 at. % Ga concentrations. We observe that regardless of the Ga concentration, the magnetic ground state predicted was anti-ferromagnetic, which is contrary to experimental results. However, the equilibrium lattice constants decrease with increasing Ga concentration, which is in agreement with experimental observations. Furthermore, when more than one Ga impurity is present within the supercell, the Ga atoms prefer to be at third nearest neighbor distance. The local effects of the bond lengths around the Ga atom, formation energies and partial density of states (PDOS) in the lowest energy structures will be discussed in detail. PDOS illustrates a Pu 6d and Ga 4p hybridization. Finally, we will also discuss the effects of a hydrogen-vacancy complex within a bulk Pu-Ga alloy. This work has been supported by the US Department of Energy through the Los Alamos National Laboratory LDRD Program.

  16. Unusual behaviour of (Np,Pu)B2C

    NASA Astrophysics Data System (ADS)

    Klimczuk, Tomasz; Boulet, Pascal; Griveau, Jean-Christophe; Colineau, Eric; Bauer, Ernst; Falmbigl, Matthias; Rogl, Peter; Wastin, Franck

    2015-02-01

    Two transuranium metal boron carbides, NpB2C and PuB2C have been synthesized by argon arc melting. The crystal structures of the {Np,Pu}B2C compounds were determined from single-crystal X-ray data to be isotypic with the ThB2C-type (space group ?, a = 0.6532(2) nm; c = 1.0769(3) nm for NpB2C and a = 0.6509(2) nm; c = 1.0818(3) nm for PuB2C; Z = 9). Physical properties have been derived from polycrystalline bulk material in the temperature range from 2 to 300 K and in magnetic fields up to 9 T. Magnetic susceptibility and heat capacity data indicate the occurrence of antiferromagnetic ordering for NpB2C with a Neel temperature TN = 68 K. PuB2C is a Pauli paramagnet most likely due to a strong hybridization of s(p,d) electrons with the Pu-5f states. A pseudo-gap, as concluded from the Sommerfeld value and the electronic transport, is thought to be a consequence of the hybridization. The magnetic behaviour of {Np,Pu}B2C is consistent with the criterion of Hill.

  17. /sup 238/Pu processing at the Savannah River Plant

    SciTech Connect

    Burney, G.A.

    1983-01-01

    /sup 238/Pu is produced by irradiating /sup 237/Np. The /sup 237/Np is produced as a byproduct when natural or enriched uranium is irradiated with neutrons. The /sup 237/Np is separated by solvent extraction and ion exchange. It is converted to NpO/sub 2/ and fabricated into targets for irradiation. The irradiated targets are cooled and dissolved in strong nitric acid. The /sup 238/Pu and /sup 237/Np are separated from fission products and other cationic impurities and from each other by three cycles of anion exchange. The /sup 237/Np is recycled to produce more targets for irradiation. The pure /sup 238/Pu solution is precipitated as Pu oxalate and calcined to PuO/sub 2/. After several powder-conditioning steps, the PuO/sub 2/ is hot pressed into fuel forms. Each form is encased in iridium for loading into a specially designed power unit for space application. 8 references, 9 figures, 1 table.

  18. Study of neutron-deficient isotopes of Fl in the 239Pu, 240Pu + 48Ca reactions

    NASA Astrophysics Data System (ADS)

    Voinov, A. A.; Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu Ts; Rykaczewski, K. P.; Abdullin, F. Sh; Dmitriev, S. N.; Grzywacz, R. K.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Tsyganov, Yu S.; Subbotin, V. G.; Sukhov, A. M.; Sabelnikov, A. V.; Vostokin, G. K.; Hamilton, J. H.; Stoyer, M. A.; Strauss, S. Y.

    2016-07-01

    The results of the experiments aimed at the synthesis of Fl isotopes in the 239Pu + 48Ca and 240Pu + 48Ca reactions are presented. The experiment was performed using the Dubna gas-filled recoil separator at the U400 cyclotron. In the 239Pu+48Ca experiment one decay of spontaneously fissioning 284Fl was detected at 245-MeV beam energy. In the 240Pu+48Ca experiment three decay chains of 285Fl were detected at 245 MeV and four decays were assigned to 284Fl at the higher 48Ca beam energy of 250 MeV. The α-decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined more precisely. The cross section of the 239Pu(48Ca,3n)284Fl reaction was observed to be about 20 times lower than those predicted by theoretical models and 50 times less than the value measured in the 244Pu+48Ca reaction. The cross sections of the 240Pu(48Ca,4-3n)284,285Fl at both 48Ca energies are similar and exceed that observed in the reaction with lighter isotope 239Pu by a factor of 10. The decay properties of the synthesized nuclei and their production cross sections indicate rapid decrease of stability of superheavy nuclei with departing from the neutron number N=184 predicted to be the next magic number.

  19. Ab initio equation-of-state and elastic properties of Pu metal and Pu-Ga alloys

    NASA Astrophysics Data System (ADS)

    Per, Soderlind; Landa, Alex

    2010-03-01

    We present results of ab initio calculations of equation-of-state and elastic properties for Pu metal and Pu-Ga alloys. For this we have employed density-functional theory (DFT) in conjunction with spin-orbit coupling and orbital polarization for the metal and coherent-potential approximation (CPA) for the alloys. All Pu systems benefit from spin polarization which is consistent with previous DFT studies of plutonium. We show that orbital correlations become more important proceeding from α->β->γ plutonium, thus suggesting increasing f-electron correlation (localization). For δ-Pu- Ga alloys we find that the system softens with larger Ga content, i.e., bulk modulus, elastic constants, and chemical bonding weakens with increasing Ga concentration. This inverse relationship is nearly linear and supported by measurements on polycrystal δ-Pu-Ga alloys. For Pu metal, our single-crystal results also relates reasonably with ultrasound data on polycrystal samples where available. The comparison is indirect but made possible by approximating the polycrystal with an isotropic (uniform strain) single crystal. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  20. On the electrochemical formation of Pu-Al alloys in molten LiCl-KCl

    NASA Astrophysics Data System (ADS)

    Mendes, E.; Malmbeck, R.; Nourry, C.; Souček, P.; Glatz, J.-P.

    2012-01-01

    Properties of Pu-Al alloys were investigated in connection with development of pyrochemical methods for reprocessing of spent nuclear fuel. Electroseparation techniques in molten LiCl-KCl are being developed in ITU to group-selectively recover actinides from the mixture with fission products. In the process, actinides are electrochemically reduced on solid aluminium cathodes, forming solid actinide-aluminium alloys. This article is focused on electro-chemical characterisation of Pu-Al alloys in molten LiCl-KCl, on electrodeposition of Pu on solid Al electrodes and on determination of chemical composition and structure of the formed alloys. Cyclic voltammetry and chronopotentiometry were used to study Pu-Al alloys in the temperature range 400-550 °C. Pu is reduced to metal in one reduction step Pu 3+/Pu 0 on an inert W electrode. On a reactive Al electrode, the reduction of Pu 3+ to Pu 0 occurs at a more positive potential due to formation of Pu-Al alloys. The open circuit potential technique was used to identify the alloys formed. Stable deposits were obtained by potentiostatic electrolyses of LiCl-KCl-PuCl 3 melts on Al plates. XRD and SEM-EDX analyses were used to characterise the alloys, which were composed mainly of PuAl 4 with some PuAl 3. In addition, the preparation of PuCl 3 containing salt by carbochlorination of PuO 2 is described.

  1. A study of accelerated radiation damage effects in PuO2 and gadolinia-stabilized cubic zirconia, Zr0.79Gd0.14Pu0.07O1.93, doped with 238Pu

    NASA Astrophysics Data System (ADS)

    Burakov, B. E.; Yagovkina, M. A.

    2015-12-01

    Polycrystalline samples of cubic zirconia, Zr0.79Gd0.14Pu0.07O1.93, doped with approximately 9.9 wt.% 238Pu, and PuO2 containing 11.0 wt. % 238Pu (and main isotope is 239Pu) have been repeatedly studied during many years by X-ray diffraction analysis. At a temperature of 25 °C the unit-cell parameter of PuO2 increases depending on accumulated dose, and is accompanied by decrease of coherent scattering region (CSR). Self-irradiation of Zr0.79Gd0.14Pu0.07O1.93 is accompanied with repeated change of unit-cell parameter and CSR.

  2. Pu and 137Cs in the Yangtze River estuary sediments: distribution and source identification.

    PubMed

    Liu, Zhiyong; Zheng, Jian; Pan, Shaoming; Dong, Wei; Yamada, Masatoshi; Aono, Tatsuo; Guo, Qiuju

    2011-03-01

    Pu isotopes and (137)Cs were analyzed using sector field ICP-MS and γ spectrometry, respectively, in surface sediment and core sediment samples from the Yangtze River estuary. (239+240)Pu activity and (240)Pu/(239)Pu atom ratios (>0.18) shows a generally increasing trend from land to sea and from north to south in the estuary. This spatial distribution pattern indicates that the Pacific Proving Grounds (PPG) source Pu transported by ocean currents was intensively scavenged into the suspended sediment under favorable conditions, and mixed with riverine sediment as the water circulated in the estuary. This process is the main control for the distribution of Pu in the estuary. Moreover, Pu is also an important indicator for monitoring the changes of environmental radioactivity in the estuary as the river basin is currently the site of extensive human activities and the sea level is rising because of global climate changes. For core sediment samples the maximum peak of (239+240)Pu activity was observed at a depth of 172 cm. The sedimentation rate was estimated on the basis of the Pu maximum deposition peak in 1963-1964 to be 4.1 cm/a. The contributions of the PPG close-in fallout Pu (44%) and the riverine Pu (45%) in Yangtze River estuary sediments are equally important for the total Pu deposition in the estuary, which challenges the current hypothesis that the riverine Pu input was the major source of Pu budget in this area.

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

    SciTech Connect

    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.

  4. Measurements Conducted on an Unknown Object Labeled Pu-239

    SciTech Connect

    Hoteling, Nathan

    2013-11-18

    Measurements were carried out on 12 November 2013 to determine whether Pu-239 was present on an object discovered in a plastic bag with label “Pu-­239 6 uCi.” Following initial survey measurements to verify that the object was not leaking or contaminated, spectra were collected with a High Purity Germanium (HPGe) detector with object positioned in two different configurations. Analysis of the spectra did not yield any direct evidence of Pu-­239. From the measured spectra, minimum detectable activity (MDA) was determined to be approximately 2 uCi for the gamma-­ray measurements. Although there was no direct evidence of Pu-239, a peak at 60 keV characteristic of Am-­241 decay was observed. Since it is very likely that Am-­241 would be present in aged plutonium samples, this was interpreted as indirect evidence for the presence of plutonium on the object. Analysis of this peak led to an estimated Pu-­239 activity of 0.02–0.04 uCi, or <1x10-6 grams.

  5. The I-Pu-Xe age of the Moon

    NASA Technical Reports Server (NTRS)

    Swindle, T. D.; Caffee, M. W.; Hohenberg, C. M.

    1984-01-01

    The Rb-Sr analyses of some lunar samples which indicate that the Moon is close to the age of primitive meteorites are only reliable to within about 100 m.y. A potentially more precise chronometer is the I-Pu-Xe system. I129 has a 17 m.y. halflife and decays to Xe129; Pu244, with an 82 m.y. halflife, produces Xe131 to Xe136 in fission. The I129/Pu244 ratio has a halflife of 21 m.y. Xenon retention for the Earth could have begun as late as the event that gave birth to the Moon. For the Moon, it is hard to imagine that xenon retention could have begun before re-accretion of the fissioned (and initially dispersed?) material, particularly if that material got hot enough to account for the depletion of the volatile elements. Thus, if fission model are correct, xenon retention in the Earth certainly began no later than in the Moon, and possibly began earlier. Therefore, the I-Pu-Xe system is only marginally consistent with a fission origin. If further study confirms that the I/U ratio of the Moon is .01 or less, or if gas-rich lunar highland breccias with higher ratios of I129 to Pu244 are found, it would be difficult to explain the results in an earth-fission model of lunar origin.

  6. Pu(V) transport through Savannah River Site soils - an evaluation of a conceptual model of surface- mediated reduction to Pu (IV).

    PubMed

    Powell, Brian A; Kaplan, Daniel I; Serkiz, Steven M; Coates, John T; Fjeld, Robert A

    2014-05-01

    Over the last fifteen years the Savannah River Site (SRS) in South Carolina, USA, was selected as the site of three new plutonium facilities: the Mixed Oxide Fuel Fabrication Facility, Pit Disassembly and Conversion Facility, and the Pu Immobilization Plant. In order to assess the potential human and environmental risk associated with these recent initiatives, improved understanding of the fate and transport of Pu in the SRS subsurface environment is necessary. The hypothesis of this study was that the more mobile forms of Pu, Pu(V) and Pu(VI), would be reduced to the less mobile Pu(III/IV) oxidation states under ambient SRS subsurface conditions. Laboratory-scale dynamic flow experiments (i.e., column studies) indicated that Pu(V) was very mobile in SRS sediments. At higher pH values the mobility of Pu decreased and the fraction of Pu that became irreversibly sorbed to the sediment increased, albeit, only slightly. Conversely, these column experiments showed that Pu(IV) was essentially immobile and was largely irreversibly sorbed to the sediment. More than 100 batch sorption experiments were also conducted with four end-member sediments, i.e., sediments that include the chemical, textural, and mineralogical properties likely to exist in the SRS. These tests were conducted as a function of initial Pu oxidation state, pH, and contact time and consistently demonstrated that although Pu(V) sorbed initially quite weakly to sediments, it slowly, over the course of <33 days, sorbed very strongly to sediments, to approximately the same degree as Pu(IV). This is consistent with our hypothesis that Pu(V) is reduced to the more strongly sorbing form of Pu, Pu(IV). These studies provide important experimental support for a conceptual geochemical model for dissolved Pu in a highly weathered subsurface environment. That is that, irrespective of the initial oxidation state of the dissolved Pu introduced into a SRS sediment system, Pu(IV) controls the environmental transport

  7. US/Russian Magnetized Target Fusion Plasma Formation Experiments

    NASA Astrophysics Data System (ADS)

    Benage, John F., Jr.; Mtf Team; Broste, W.; Westley, D.; Mago Team

    1998-11-01

    Magnetized target fusion (MTF) is a potentially very low cost route to producing a fusion energy source. Many of MTF's plasma properties are intermediate between magnetically confined fusion (MFE) and inertially confined fusion (ICF). MTF consists of first producing a magnetically thermally insulated target plasma with a temperature of 100 eV or more with a lifetime of 5-10 microseconds. The target plasma is then compressed to fusion conditions by a magnetically driven imploding liner. One target plasma candidate is VNIIEF's MAGO, in which a cylindrical chamber with two cavities is filled with DT gas at a pressure of 10 Torr and driven by a current of 2-8 MA. A series of experiments under different plasma conditions have been performed to evaluate MAGO as an MTF target plasma. Diagnostics used to characterize the MAGO plasma include B dot probes to measure the current distribution, filtered silicon diodes to measure the spectrum and duration of the plasma radiation and a UV spectrometer to measure impurity line radiation.

  8. LA-ICP-MS for Pu source identification at Mayak PA, the Urals, Russia.

    PubMed

    Cagno, S; Hellemans, K; Lind, O C; Skipperud, L; Janssens, K; Salbu, B

    2014-02-01

    Information on Pu in environmental samples is traditionally based on the determination of the (240+239)Pu activity via Alpha Spectrometry (AS). A large number of alpha spectrometry sources (planchettes) containing radiochemically separated Pu are therefore stored worldwide and are available for further analyses. These archive samples represent a resource from which valuable information on isotopic composition of alpha emitters including Pu can be obtained. The relative abundances of Pu isotopes can be used to trace specific Pu sources and characterize the relative contributions of different Pu sources in a sample. Thus, in addition to the total (239+240)Pu activity, determination of the (240)Pu/(239)Pu ratio can provide valuable information on the nature of the Pu emitting sources. The Pu isotopic ratios can be determined by mass spectrometry techniques such as Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICPMS) or Accelerator Mass Spectrometry (AMS) that require dissolution and complete destruction of the material deposited on the planchettes. In this study Laser Ablation (LA)-quadrupole-ICP-MS has been employed for the analysis of (239)Pu/(240)Pu ratios from alpha-planchettes prepared from samples originating from the Mayak PA nuclear facility, Russia. The results are compared with data from AMS and show that the (240)Pu/(239)Pu ratios obtained by LA-ICP-MS can be utilized to distinguish weapons-grade Pu from civil reprocessing sources. Moreover, isotope ratio mapping can also be performed across the planchettes, allowing e.g. the visualization of possible inhomogeneities in the Pu-isotope distribution on their surface. Thus, this solid sample technique can be applied to extract additional information from existing archives of samples. PMID:24424783

  9. Characterization of Pu concentration and its isotopic composition in a reference fallout material.

    PubMed

    Zhang, Yongsan; Zheng, Jian; Yamada, Masatoshi; Wu, Fengchang; Igarashi, Yasuhito; Hirose, Katsumi

    2010-02-01

    Because there is no reference material for fallout plutonium isotope monitoring, preparation of such a material is necessary for quality control of fallout radionuclides analysis for atmospheric environmental studies. In this work, we report the characterization of Pu activity and its isotopic composition in a reference fallout material prepared by the Meteorological Research Institute (MRI), Japan. This material was prepared from samples collected at 14 stations throughout Japan in 1963-1979, with reference values of (137)Cs, (90)Sr and (239)(+)(240)Pu activities. We analyzed the activities of (239)(+)(240)Pu and (241)Pu, and the atom ratios of (240)Pu/(239)Pu and (241)Pu/(239)Pu using an isotope dilution sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS). The (239)(+)(240)Pu activities in this fallout material using acid leaching and total digestion were 6.56+/-0.20 mBq/g and 6.79+/-0.16 mBq/g, respectively. Atom ratios of (240)Pu/(239)Pu were 0.1915+/-0.0030 and 0.1922+/-0.0044, respectively. Both (240)Pu/(239)Pu and (241)Pu/(239)Pu atom ratios were slightly higher than those of global fallout, which could be attributed to the deposition of fallout radionuclides resulting from the Chinese nuclear weapons tests conducted in the 1970s. The dominant host phases of (239)(+)(240)Pu were found to be organic matter-sulfides (70%) with a relative high (240)Pu/(239)Pu atom ratio, and Fe-Mn oxides (19%) using a sequential extraction method.

  10. LA-ICP-MS for Pu source identification at Mayak PA, the Urals, Russia.

    PubMed

    Cagno, S; Hellemans, K; Lind, O C; Skipperud, L; Janssens, K; Salbu, B

    2014-02-01

    Information on Pu in environmental samples is traditionally based on the determination of the (240+239)Pu activity via Alpha Spectrometry (AS). A large number of alpha spectrometry sources (planchettes) containing radiochemically separated Pu are therefore stored worldwide and are available for further analyses. These archive samples represent a resource from which valuable information on isotopic composition of alpha emitters including Pu can be obtained. The relative abundances of Pu isotopes can be used to trace specific Pu sources and characterize the relative contributions of different Pu sources in a sample. Thus, in addition to the total (239+240)Pu activity, determination of the (240)Pu/(239)Pu ratio can provide valuable information on the nature of the Pu emitting sources. The Pu isotopic ratios can be determined by mass spectrometry techniques such as Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICPMS) or Accelerator Mass Spectrometry (AMS) that require dissolution and complete destruction of the material deposited on the planchettes. In this study Laser Ablation (LA)-quadrupole-ICP-MS has been employed for the analysis of (239)Pu/(240)Pu ratios from alpha-planchettes prepared from samples originating from the Mayak PA nuclear facility, Russia. The results are compared with data from AMS and show that the (240)Pu/(239)Pu ratios obtained by LA-ICP-MS can be utilized to distinguish weapons-grade Pu from civil reprocessing sources. Moreover, isotope ratio mapping can also be performed across the planchettes, allowing e.g. the visualization of possible inhomogeneities in the Pu-isotope distribution on their surface. Thus, this solid sample technique can be applied to extract additional information from existing archives of samples.

  11. ICE1 of Pyrus ussuriensis functions in cold tolerance by enhancing PuDREBa transcriptional levels through interacting with PuHHP1

    NASA Astrophysics Data System (ADS)

    Huang, Xiaosan; Li, Kongqing; Jin, Cong; Zhang, Shaoling

    2015-12-01

    ICE1 transcription factor plays an important role in plant cold stress via regulating the expression of stress-responsive genes. In this study, a PuICE1 gene isolated from Pyrus ussuriensis was characterized for its function in cold tolerance. The expression levels of the PuICE1 were induced by cold, dehydration and salt, with the greatest induction under cold conditions. PuICE1 was localized in the nucleus and could bind specifically to the MYC element in the PuDREBa promoter. The PuICE1 fused to the GAL4 DNA-binding domain to have transcriptional activation activity. Ectopic expression of the PuICE1 in tomato conferred enhanced tolerance to cold stress at cold temperatures, less electrolyte leakage, less MDA content, higher chlorophyll content, higher survival rate, higher proline content, higher activities of enzymes. In additon, steady-state mRNA levels of six stress-responsive genes coding for either functional or regulatory genes were induced to higher levels in the transgenic lines by cold stress. Yeast two-hybrid, transient assay, split luciferase complementation and BiFC assays all revealed that PuHHP1 protein can physically interact with PuICE1. Taken together, these results demonstrated that PuICE1 plays a positive role in cold tolerance, which may be due to enhancement of PuDREBa transcriptional levels through interacting with the PuHHP1.

  12. ICE1 of Pyrus ussuriensis functions in cold tolerance by enhancing PuDREBa transcriptional levels through interacting with PuHHP1

    PubMed Central

    Huang, Xiaosan; Li, Kongqing; Jin, Cong; Zhang, Shaoling

    2015-01-01

    ICE1 transcription factor plays an important role in plant cold stress via regulating the expression of stress-responsive genes. In this study, a PuICE1 gene isolated from Pyrus ussuriensis was characterized for its function in cold tolerance. The expression levels of the PuICE1 were induced by cold, dehydration and salt, with the greatest induction under cold conditions. PuICE1 was localized in the nucleus and could bind specifically to the MYC element in the PuDREBa promoter. The PuICE1 fused to the GAL4 DNA-binding domain to have transcriptional activation activity. Ectopic expression of the PuICE1 in tomato conferred enhanced tolerance to cold stress at cold temperatures, less electrolyte leakage, less MDA content, higher chlorophyll content, higher survival rate, higher proline content, higher activities of enzymes. In additon, steady-state mRNA levels of six stress-responsive genes coding for either functional or regulatory genes were induced to higher levels in the transgenic lines by cold stress. Yeast two-hybrid, transient assay, split luciferase complementation and BiFC assays all revealed that PuHHP1 protein can physically interact with PuICE1. Taken together, these results demonstrated that PuICE1 plays a positive role in cold tolerance, which may be due to enhancement of PuDREBa transcriptional levels through interacting with the PuHHP1. PMID:26626798

  13. Sources and distributions of 137Cs, 238Pu, 239,240Pu radionuclides in the north-western Barents Sea.

    PubMed

    Zaborska, Agata; Mietelski, Jerzy Wojciech; Carroll, JoLynn; Papucci, Carlo; Pempkowiak, Janusz

    2010-04-01

    Sediment deposits are the ultimate sink for anthropogenic radionuclides entering the marine environment. The major sources of anthropogenic radionuclides to the Barents Sea are fallout from nuclear weapons tests, long range transport from other seas, and river and non-point freshwater supplies. In this study we investigated activity concentrations, ratios, and inventories of the anthropogenic radionuclides, 137Cs, 238Pu, 239,240Pu in dated sediment cores collected along a north-south transect in the northwestern Barents Sea. The data were used to evaluate the influence of different sources on the derived spatial and temporal patterns of anthropogenic radionuclides in seafloor sediment deposits. Activity concentrations of 137Cs ranged from <0.1 Bq/kg to 10.5 Bq/kg while 239,240Pu ranged from <0.01 Bq/kg to 2.74 Bq/kg and 238Pu activity concentrations ranged from <0.01 Bq/kg to 0.22 Bq/kg. Total inventories of 137Cs ranged from 29.5+/-1.5 Bq/m2 to 152.7+/-5.6 Bq/m2 and for 239,240Pu inventories (6 sediment layers only) ranged from 9.5+/-0.3 Bq/m2 to 29.7+/-0.4 Bq/m2. Source contributions varied among stations and between the investigated radionuclides. The 238Pu/239,240Pu ratios up to 0.18 indicate discharges from nuclear fuel reprocessing plants as a main contributor of plutonium. Based on 238Pu/239,240Pu ratio, it was calculated that up to 19-27% of plutonium is supplied from sources other than atmospheric global fallout. Taking into account Atlantic current flow trajectories and that both activity concentrations and inventories of plutonium negatively correlate with latitude, Sellafield is a major source for the Barents Sea. Concentrations and inventories of 137Cs correlate positively with latitude and negatively with distance from the Svalbard archipelago. The 137Cs concentrations are highest in an area of intensive melting of sea ice formed along the Siberian coast. Thus, sea ice and supplies from Svalbard may be important source of 137Cs to the Barents Sea

  14. U, Pu, and Am nuclear signatures of the Thule hydrogen bomb debris.

    PubMed

    Eriksson, Mats; Lindahl, Patric; Roos, Per; Dahlgaard, Henning; Holm, Elis

    2008-07-01

    This study concerns an arctic marine environment that was contaminated by actinide elements after a nuclear accident in 1968, the so-called Thule accident In this study we have analyzed five isolated hot particles as well as sediment samples containing particles from the weapon material for the determination of the nuclear fingerprint of the accident. We report that the fissile material in the hydrogen weapons involved in the Thule accident was a mixture of highly enriched uranium and weapon-grade plutonium and that the main fissile material was 235U (about 4 times more than the mass of 239Pu). In the five hot particles examined, the measured uranium atomic ratio was 235U/238U = 1.02 +/- 0.16 and the Pu-isotopic ratios were as follows: 24Pu/239Pu = 0.0551 +/- 0.0008 (atom ratio), 238Pu/239+240Pu = 0.0161 +/- 0.0005 (activity ratio), 241Pu/239+240Pu = 0.87 +/- 0.12 (activity ratio), and 241Am/ 239+240Pu = 0.169 +/- 0.005 (activity ratio) (reference date 2001-10-01). From the activity ratios of 241Pu/241Am, we estimated the time of production of this weapon material to be from the late 1950s to the early 1960s. The results from reanalyzed bulk sediment samples showed the presence of more than one Pu source involved in the accident, confirming earlier studies. The 238Pu/239+240PU activity ratio and the 240Pu/ 239Pu atomic ratio were divided into at least two Pu-isotopic ratio groups. For both Pu-isotopic ratios, one ratio group had identical ratios as the five hot particles described above and for the other groups the Pu isotopic ratios were lower (238Pu/ 239+240PU activity ratio approximately 0.01 and the 240Pu/P239Pu atomic ratio 0.03). On the studied particles we observed that the U/Pu ratio decreased as a function of the time these particles were present in the sediment. We hypothesis that the decrease in the ratio is due to a preferential leaching of U relative to Pu from the particle matrix. PMID:18677996

  15. U, Pu, and Am nuclear signatures of the Thule hydrogen bomb debris.

    PubMed

    Eriksson, Mats; Lindahl, Patric; Roos, Per; Dahlgaard, Henning; Holm, Elis

    2008-07-01

    This study concerns an arctic marine environment that was contaminated by actinide elements after a nuclear accident in 1968, the so-called Thule accident In this study we have analyzed five isolated hot particles as well as sediment samples containing particles from the weapon material for the determination of the nuclear fingerprint of the accident. We report that the fissile material in the hydrogen weapons involved in the Thule accident was a mixture of highly enriched uranium and weapon-grade plutonium and that the main fissile material was 235U (about 4 times more than the mass of 239Pu). In the five hot particles examined, the measured uranium atomic ratio was 235U/238U = 1.02 +/- 0.16 and the Pu-isotopic ratios were as follows: 24Pu/239Pu = 0.0551 +/- 0.0008 (atom ratio), 238Pu/239+240Pu = 0.0161 +/- 0.0005 (activity ratio), 241Pu/239+240Pu = 0.87 +/- 0.12 (activity ratio), and 241Am/ 239+240Pu = 0.169 +/- 0.005 (activity ratio) (reference date 2001-10-01). From the activity ratios of 241Pu/241Am, we estimated the time of production of this weapon material to be from the late 1950s to the early 1960s. The results from reanalyzed bulk sediment samples showed the presence of more than one Pu source involved in the accident, confirming earlier studies. The 238Pu/239+240PU activity ratio and the 240Pu/ 239Pu atomic ratio were divided into at least two Pu-isotopic ratio groups. For both Pu-isotopic ratios, one ratio group had identical ratios as the five hot particles described above and for the other groups the Pu isotopic ratios were lower (238Pu/ 239+240PU activity ratio approximately 0.01 and the 240Pu/P239Pu atomic ratio 0.03). On the studied particles we observed that the U/Pu ratio decreased as a function of the time these particles were present in the sediment. We hypothesis that the decrease in the ratio is due to a preferential leaching of U relative to Pu from the particle matrix.

  16. Transuranic concentrations in reef and pelagic fish from the Marshall Islands. [/sup 239/Pu, /sup 240/Pu

    SciTech Connect

    Noshkin, V.E.; Eagle, R.J.; Wong, K.M.; Jokela, T.A.

    1980-09-01

    Concentrations of /sup 239 + 240/Pu are reported in tissues of several species of reef and pelagic fish caught at 14 different atolls in the northern Marshall Islands. Several regularities that are species dependent are evident in the distribution of /sup 239 + 240/Pu among different body tissues. Concentrations in liver always exceeded those in bone and concentrations were lowest in the muscle of all fish analyzed. A progressive discrimination against /sup 239 + 240/Pu was observed at successive trophic levels at all atolls except Bikini and Enewetak, where it was difficult to conclude if any real difference exists between the average concentration factor for /sup 239 + 240/Pu among all fish, which include bottom feeding and grazing herbivores, bottom feeding carnivores, and pelagic carnivores from different atoll locations. The average concentration of /sup 239 + 240/Pu in the muscle of surgeonfish from Bikini and Enewetak was not significantly different from the average concentrations determined in these fish at the other, lesser contaminated atolls. Concentrations among all 3rd, 4th, and 5th trophic level species are highest at Bikini where higher environmental concentrations are found. The reasons for the anomalously low concentrations in herbivores from Bikini and Enewetak are not known.

  17. Nuclear Magnetic Resonance Measurements and Electronic Structure of Pu(IV) in [(Me)4N]2PuCl6.

    PubMed

    Mounce, Andrew M; Yasuoka, Hiroshi; Koutroulakis, Georgios; Lee, Jeongseop A; Cho, Herman; Gendron, Frédéric; Zurek, Eva; Scott, Brian L; Trujillo, Julie A; Slemmons, Alice K; Cross, Justin N; Thompson, Joe D; Kozimor, Stosh A; Bauer, Eric D; Autschbach, Jochen; Clark, David L

    2016-09-01

    The synthesis, electronic structure, and characterization via single-crystal X-ray diffraction, nuclear magnetic resonance (NMR) spectroscopy, and magnetic susceptibility of (Me4N)2PuCl6 are reported. NMR measurements were performed to both search for the direct (239)Pu resonance and to obtain local magnetic and electronic information at the Cl site through (35)Cl and (37)Cl spectra. No signature of (239)Pu NMR was observed. The temperature dependence of the Cl spectra was simulated by diagonalizing the Zeeman and quadrupolar Hamiltonians for (35)Cl, (37)Cl, and (14)N isotopes. Electronic structure calculations predict a magnetic Γ5 triplet ground state of Pu(IV) in the crystalline electric field of the undistorted PuCl6 octahedron. A tetragonal distortion would result in a very small splitting (∼20 cm(-1)) of the triplet ground state into a nonmagnetic singlet and a doublet state. The Cl shifts have an inflection point at T ≈ 15 K, differing from the bulk susceptibility, indicating a nonmagnetic crystal field ground state. The Cl spin-lattice relaxation time is constant to T = 15 K, below which it rapidly increases, also supporting the nonmagnetic crystal field ground state.

  18. Deducing the 236Pu(n,f) and 237Pu(n,f) cross sections via the surrogate ratio method

    NASA Astrophysics Data System (ADS)

    Hughes, R. O.; Beausang, C. W.; Ross, T. J.; Burke, J. T.; Casperson, R. J.; McCleskey, M.; Cooper, N.; Escher, J. E.; Gell, K. B.; Good, E.; Humby, P.; Saastimoinen, A.; Tarlow, T. D.

    2013-10-01

    The short half-lives associated with certain minor actinide nuclei that are relevant to stockpile stewardship pursuits and the development of next-generation nuclear reactors make direct neutron measurements very challenging. In certain cases, a stable beam and target ``surrogate reaction'' can be used in lieu of the neutron-induced reaction, and the (n,f) cross section can then be deduced indirectly. Agreement between surrogate and direct measurements for (n,f) cross sections in actinide nuclei is usually within 10%. The present work reports on the measurement of the 236Pu(n,f) and 237Pu(n,f) cross sections via 239Pu(p,tf) and 239Pu(p,df) surrogate reactions, respectively. The experiment was performed at the Texas A&M University Cyclotron Facility using a 28.5 MeV proton beam to bombard 239Pu and 235U targets. Outgoing light ions were detected in coincidence with fission fragments using the STAR-LiTe detector array. Results of the analysis will be presented. This work was supported by DoE Grant Numbers: DE-FG52-09NA29454 and DE-FG02-05ER41379 (Richmond), DE-AC52-07NA27344 (LLNL) and DE-FG52-09NA29467 (TAMU).

  19. Pu236(n,f), Pu237(n,f), and Pu238(n,f) cross sections deduced from (p,t), (p,d), and (p,p') surrogate reactions

    NASA Astrophysics Data System (ADS)

    Hughes, R. O.; Beausang, C. W.; Ross, T. J.; Burke, J. T.; Casperson, R. J.; Cooper, N.; Escher, J. E.; Gell, K.; Good, E.; Humby, P.; McCleskey, M.; Saastimoinen, A.; Tarlow, T. D.; Thompson, I. J.

    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.

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

    NASA Technical Reports Server (NTRS)

    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. Determination of Plutonium Activity Concentrations and 240Pu/239Pu Atom Ratios in Brown Algae (Fucus distichus) Collected from Amchitka Island, Alaska.

    SciTech Connect

    Hamilton, T F; Brown, T A; Marchetti, A A; Martinelli, R E; Kehl, S R

    2005-05-02

    Plutonium-239 ({sup 239}Pu) and plutonium-240 ({sup 240}Pu) activity concentrations and {sup 240}Pu/{sup 239}Pu atom ratios are reported for Brown Algae (Fucus distichus) collected from the littoral zone of Amchitka Island (Alaska) and at a control site on the Alaskan peninsula. Plutonium isotope measurements were performed in replicate using Accelerator Mass Spectrometry (AMS). The average {sup 240}Pu/{sup 239}Pu atom ratio observed in dried Fucus d. collected from Amchitka Island was 0.227 {+-} 0.007 (n=5) and compares with the expected {sup 240}Pu/{sup 239}Pu atom ratio in integrated worldwide fallout deposition in the Northern Hemisphere of 0.1805 {+-} 0.0057 (Cooper et al., 2000). In general, the characteristically high {sup 240}Pu/{sup 239}Pu content of Fucus d. analyzed in this study appear to indicate the presence of a discernible basin-wide secondary source of plutonium entering the marine environment. Of interest to the study of plutonium source terms within the Pacific basin are reports of elevated {sup 240}Pu/{sup 239}Pu atom ratios in fallout debris from high-yield atmospheric nuclear tests conducted in the Marshall Islands during the 1950s (Diamond et al., 1960), the wide range of {sup 240}Pu/{sup 239}Pu atom ratio values (0.19 to 0.34) observed in sea water, sediments, coral and other environmental media from the North Pacific Ocean (Hirose et al., 1992; Buesseler, 1997) and updated estimates of the relative contributions of close-in and intermediate fallout deposition on oceanic inventories of radionuclidies, especially in the Northern Pacific Ocean (Hamilton, 2004).

  2. Reductive dissolution of Pu(IV) by Clostridium sp. under anaerobic conditions.

    PubMed

    Francis, Arokiasamy J; Dodge, Cleveland J; Gillow, Jeffrey B

    2008-04-01

    An anaerobic, gram positive, spore-forming bacterium Clostridium sp., common in soils and wastes, capable of reduction of Fe(III) to Fe(II), Mn(IV) to Mn(II), Tc(VII) to Tc(IV), and U(VI) to U(IV), reduced Pu(IV) to Pu(III). Addition of 242Pu (IV)-nitrate to the bacterial growth medium at pH 6.4 resulted in the precipitation of Pu as amorphous Pu(OH)4 due to hydrolysis and polymerization reactions. The Pu (1 x 10(-5) M) had no effect upon growth of the bacterium as evidenced by glucose consumption; carbon dioxide and hydrogen production; a decrease in pH of the medium from 6.4 to 3.0 due to production of acetic and butyric acids from glucose fermentation; and a change in the Eh of the culture medium from +50 to -180 mV. Commensurate with bacterial growth, Pu was rapidly solubilized as evidenced by an increase in Pu concentration in solution which passed through a 0.03 microm filtration. Selective solvent extraction of the culture by thenoyltrifluoroacetone (TTA) indicated the presence of a reduced Pu species in the soluble fraction. X-ray absorption near edge spectroscopic (XANES) analysis of Pu in the culture sample at the Pu LIII absorption edge (18.054 keV) showed a shift of -3 eV compared to a Pu(IV) standard indicating reduction of Pu(IV) to Pu(III). These results suggestthat, although Pu generally exists as insoluble Pu(IV) in the environment, under appropriate conditions, anaerobic microbial activity could affect the long-term stability and mobility of Pu by its reductive dissolution.

  3. PREFACE: MEM11: The 6th International Workshop on Mechanical-Electromagnetic Properties of Composite Superconductors (Okinawa, Japan, 5-7 December 2011) MEM11: The 6th International Workshop on Mechanical-Electromagnetic Properties of Composite Superconductors (Okinawa, Japan, 5-7 December 2011)

    NASA Astrophysics Data System (ADS)

    Awaji, Satoshi; Osamura, Kozo; Hampshire, Damian

    2012-05-01

    The effect of stress and strain on the electromagnetic properties of superconducting composite conductors is one of the key issues for the practical application of superconductivity. To discuss these subjects thoroughly, the International Workshop on Mechanical-Electromagnetic Properties of Composite Superconductors (MEM) has been held regularly since 2001. The 6th workshop (MEM11) was held in Okinawa, Japan in 2011, which was the centennial of the discovery of superconductivity by Professor Kamerlingh Onnes, as well as the 25th anniversary of the discovery of high temperature superconductors (HTS). Although it was originally planned that MEM11 be held in Mito, the workshop venue was changed because of the serious disaster in the north of Japan on 11 March 2011. Sixty five scientists participated in this specialized workshop. Fifty six papers were presented in the following six sessions: (1) Intrinsic strain effects on low temperature superconductors (LTS) and HTS, (2) The International Thermonuclear Experimental Reactor (ITER), (3) Strain evaluation by quantum beams, (4) Flux pinning properties of HTS, (5) Standardization and the Versailles Project on Advanced Materials and Standards (VAMAS) and (6) High field magnets. Several large topics were presented and discussed at the workshop: the important progress in methods for non-invasive measurements of the local strain exerted on the superconducting components in superconducting wires and cables using quantum beam techniques. This approach provides powerful tools for investigating the effect of strain in composite superconductors; the intrinsic strain effects in LTS and HTS in the reversible strain region. Recently, it has become easier to determine quantitatively the strain dependence of critical current when the local strain is measured directly, and the mechanical and electromagnetic properties of the superconductors used in the ITER tokamak. This was a major topic at the workshop since the superconducting

  4. Biogeochemical Cycling and Environmental Stability of Pu Relevant to Long-Term Stewardship of DOE Sites

    SciTech Connect

    Santschi, Peter H.

    2006-06-01

    The overall objective of this proposed research is to understand the biogeochemical cycling of Pu in environments of interest to long-term DOE stewardship issues. Central to Pu cycling (transport initiation to immobilization) is the role of microorganisms. The hypothesis underlying this proposal is that microbial activity is the causative agent in initiating the mobilization of Pu in near-surface environments: through the transformation of Pu associated with solid phases, production of extracellular polymeric substances (EPS) carrier phases, and the creation of microenvironments. Also, microbial processes are central to the immobilization of Pu species, through the metabolism of organically complexed Pu species and Pu associated with extracellular carrier phases and the creation of environments favorable for Pu transport retardation.

  5. Microautoradiography in studies of Pu(V) sorption by trace and fracture minerals in tuff

    SciTech Connect

    Vaniman, D.; Furlano, A.; Chipera, S.; Thompson, J.; Triay, I.

    1996-12-31

    Microautoradiography was used to evaluate the mineralogic basis of Pu(V) retention by tuffs from Yucca Mountain, Nevada. Altered orthopyroxenes and oxide minerals are associated with high Pu retention but are limited to specific stratigraphic horizons. A weaker but more general association of Pu with smectite occurs in most samples. Thin-sections that cross fractures allow comparative studies of Pu retention by fracture-lining versus matrix minerals. Using Ag metal in emulsions as a measure of underlying Pu concentration, electron-microprobe analysis can quantify Pu retention along fracture walls and provide mineral/mineral Pu retention factors. For smectite-lined microfractures in zeolitized tuff, the smectite/clinoptilolite Pu retention factor is >80.

  6. Biogeochemical Cycling and Environmental Stability of Pu Relevant to Long-Term Stewardship of DOE Sites

    SciTech Connect

    Honeyman, Bruce D.; Francis, A.J.; Gillow, Jeffrey B.; Dodge, Cleveland J.; Santschi, Peter H.; Chin-Chang Hung; Diaz, Angelique; Tinnacher, Ruth; Roberts, Kimberly; Schwehr, Kathy

    2006-04-05

    The overall objective of this research is to understand the biogeochemical cycling of Pu in environments of interest to long-term DOE stewardship issues. Central to Pu cycling (transport initiation and immobilization) is the role of microorganisms. The hypothesis underlying this work is that microbial activity is the causative agent in initiating the mobilization of Pu in near-surface environments: through the transformation of Pu associated with solid phases, production of extracellular polymeric substances (EPS) carrier phases and the creation of microenvironments. Also, microbial processes are central to the immobilization of Pu species, through the metabolism of organically complexed Pu species and Pu associated with extracellular carrier phases and the creation of environments favorable for Pu transport retardation.

  7. Biogeochemical Cycling and Environmental Stability of Pu Relevant to Long-Term Stewardship of DOE Sites

    SciTech Connect

    Francis, Arokiasamy J.; Santschi, Peter H.; Honeyman, Bruce D.

    2005-06-01

    The overall objective of this proposed research is to understand the biogeochemical cycling of Pu in environments of interest to long-term DOE stewardship issues. Central to Pu cycling (transport initiation to immobilization) is the role of microorganisms. The hypothesis underlying this proposal is that microbial activity is the causative agent in initiating the mobilization of Pu in near-surface environments: through the transformation of Pu associated with solid phases, production of extracellular polymeric substances (EPS) carrier phases, and the creation of microenvironments. Also, microbial processes are central to the immobilization of Pu species, through the metabolism of organically complexed Pu species and Pu associated with extracellular carrier phases and the creation of environments favorable for Pu transport retardation.

  8. Global fallout Pu recorded in lacustrine sediments in Lake Hongfeng, SW China.

    PubMed

    Zheng, Jian; Wu, Fengchang; Yamada, Masatoshi; Liao, Haiqing; Liu, Congqiang; Wan, Guojiang

    2008-03-01

    Studies on the distribution and isotope compositions of fallout Pu are important for source characterization of possible future non-fallout Pu contamination in aquatic environments, and useful for dating of recent sediments to understand the pollution history of environmental contaminants. We present the historical record of atmospheric Pu fallout reconstructed from a sediment core from Lake Hongfeng, China. The Pu activity profile was in agreement with the 137Cs profile. Inventories were 50.7 Bq m(-2) for 239+240Pu and 1586 Bq m(-2) for 137Cs. The average 240Pu/239Pu atom ratio was 0.185+/-0.009, indicating that Pu originated from global stratospheric fallout rather than from direct tropospheric or close-in fallout from the Chinese nuclear testing conducted in the 1970s. Our data suggested that Lake Hongfeng would be an ideal setting for monitoring atmospheric fallout and environmental changes in this region.

  9. Induction of liver tumors by /sup 239/Pu citrate of /sup 239/PuO/sub 2/ particles in the Chinese hamster

    SciTech Connect

    Brooks, A.L.; Benjamin, S.A.; Hahn, F.F.; Brownstein, D.G.; Griffith, W.C.; McClellan, R.O.

    1983-10-01

    The influence of radiation dose distribution on the frequency of /sup 239/Pu-induced liver tumors was evaluated in the Chinese hamster. Different concentrations of /sup 239/Pu citrate or /sup 239/PuO/sub 2/ particles of known sizes were injected intravenously via the jugular vein. About 60% of the injected /sup 23/Pu citrate was deposited in the liver and 40% in the bone. The /sup 239/Pu citrate was rather uniformly distributed throughout the liver parenchyma. Injected plutonium oxide particles were taken up by the reticuloendothelial system with 90% of the body burden deposited in the liver. The /sup 239/PuO/sub 2/ particles were localized in the Kupffer cells and produced nonuniform dose distributions that were dependent on particle size. There was an activity- and dose-dependent increase in the incidence of total liver parenchymal cell tumors following injection with either plutonium particles or citrate. Plutonium citrate also produced hemangiosarcomas of the liver and tumors in bone and bone marrow. The latent period for liver tumor appearance in animals exposed to /sup 239/Pu citrate or /sup 239/PuO/sub 2/ particles increased as the injected activity decreased. These data indicate that, in Chinese hamster liver, local radiation dose distribution is less important in altering tumor incidence than injected activity or average dose. However, the more uniform irradiation from /sup 239/Pu citrate administration was more effective in cancer production than the nonuniform irradiation from /sup 239/PuO/sub 2/ particle.

  10. Atomic Structure and Phase Transformations in Pu Alloys

    SciTech Connect

    Schwartz, A J; Cynn, H; Blobaum, K M; Wall, M A; Moore, K T; Evans, W J; Farber, D L; Jeffries, J R; Massalski, T B

    2008-04-28

    Plutonium and plutonium-based alloys containing Al or Ga exhibit numerous phases with crystal structures ranging from simple monoclinic to face-centered cubic. Only recently, however, has there been increased convergence in the actinides community on the details of the equilibrium form of the phase diagrams. Practically speaking, while the phase diagrams that represent the stability of the fcc {delta}-phase field at room temperature are generally applicable, it is also recognized that Pu and its alloys are never truly in thermodynamic equilibrium because of self-irradiation effects, primarily from the alpha decay of Pu isotopes. This article covers past and current research on several properties of Pu and Pu-(Al or Ga) alloys and their connections to the crystal structure and the microstructure. We review the consequences of radioactive decay, the recent advances in understanding the electronic structure, the current research on phase transformations and their relations to phase diagrams and phase stability, the nature of the isothermal martensitic {delta} {yields} {alpha}{prime} transformation, and the pressure-induced transformations in the {delta}-phase alloys. New data are also presented on the structures and phase transformations observed in these materials following the application of pressure, including the formation of transition phases.

  11. Characterization of Pu-238 Heat Source Granule Containment

    SciTech Connect

    Richardson, Paul Dean II; Sanchez, Joey Leo; Wall, Angelique Dinorah; Chavarria, Rene

    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).

  12. Selection and Evaluation of a new Pu Density Measurement Fluid

    SciTech Connect

    Dziewinska, Krystyna; Peters, Michael A; Martinez, Patrick P; Dziewinski, Jacek J; Pugmire, David L; Trujillo, Stephen M; La Verne, Jake A; Rajesh, P

    2009-01-01

    This paper summarizes efforts leading to selection of a new fluid for the determination of the density of large Pu parts. Based on an extended literature search, perfluorotributylamine (FC-43) was chosen for an experimental study. Plutonium coupon corrosion studies were performed by exposing Pu to deaerated and aerated solutions and measuring corrosion gravimetrically. Corrosion rates were determined. Samples of deaerated and aerated perfuluorotributylamine (FC-43) were also irradiated with {sup 60}Co gamma rays (96 Gy/min) to various doses. The samples were extracted with NaOH and analyzed by IC and showed the presence of F and Cl{sup -}. The G-values were established. In surface study experiments Pu coupons were exposed to deaerated and aerated solutions of FC-43 and analyzed by X-ray photoelectron spectroscopy (XPS). The XPS data indicate that there is no detectable surface effect caused by the new fluid. In conclusion the FC-43 was determined to be a very effective and practical fluid for Pu density measurements.

  13. XAFS and LIBD Investigation of the Formation and Structure of Pu(IV) Hydrolysis Products

    SciTech Connect

    Rothe, J.; Walther, C.; Denecke, M.A.; Fanghänel, Th.

    2010-11-16

    Pu(IV) oxyhydroxide colloid growth is investigated with XAFS and LIBD. From combined results a model of colloid formation is proposed, which leads to a face-centered cubic Pu sublattice having cation defects, as observed with EXAFS, and a linear dependency of log [Pu(IV)] on -log [H{sup +}] with slope -2, in accord with LIBD. The solubility for Pu(IV) measured with LIBD is close to the lower limit of the solubility curve from previously reported data.

  14. Bulk characterization of (U, Pu) mixed carbide fuel for distribution of plutonium

    SciTech Connect

    Devi, K. V. Vrinda Khan, K. B.; Biju, K.; Kumar, Arun

    2015-06-24

    Homogeneous distribution of plutonium in (U, Pu) mixed fuels is important from fuel performance as well as reprocessing point of view. Radiation imaging and assay techniques are employed for the detection of Pu rich agglomerates in the fuel. A simulation study of radiation transport was carried out to analyse the technique of autoradiography so as to estimate the minimum detectability of Pu agglomerates in MC fuel with nominal PuC content of 70% using Monte Carlo simulations.

  15. DENSITY-FUNCTIONAL STUDY OF Zr-BASED ACTINIDE ALLOYS: 2. U-Pu-Zr SYSTEM

    SciTech Connect

    Landa, A; Soderlind, P; Turchi, P; Vitos, L; Ruban, A

    2009-02-09

    Density-functional theory, previously used to describe phase equilibria in the U-Zr alloys [1], is applied to study ground state properties of the bcc U-Pu-Zr solid solutions. Calculated heats of formation of the Pu-U and Pu-Zr alloys are in a good agreement with CALPHAD assessments. We found that account for spin-orbit coupling is important for successful description of Pu-containing alloys.

  16. Ultra-trace determination of (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu by triple quadruple collision/reaction cell-ICP-MS/MS: Establishing a baseline for global fallout in Qatar soil and sediments.

    PubMed

    Amr, Mohamed A; Helal, Abdul-Fattah I; Al-Kinani, Athab T; Balakrishnan, Perumal

    2016-03-01

    The development of practical, fast, and reliable methods for the ultra-trace determination of anthropogenic radionuclides (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu by triple quadruple collision/reaction cell inductively coupled plasma mass spectrometry (CRC-ICP-MS/MS) were investigated in term of its accuracy and precision for producing reliable results. The radionuclides were extracted from 1 kg of the environmental soil samples by concentrated nitric and hydrochloric acids. The leachate solutions were measured directly by triple quadrupole CRC-ICP-MS/MS. For quality assurance, a chemical separation of the concerned radionuclides was conducted and then measured by single quadrupole-ICP-MS. The developed methods were next applied to measure the anthropogenic radionuclides (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu in soil samples collected throughout the State of Qatar. The average concentrations of (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu were 0.606 fg/g (3.364 Bq/kg), 0.619 fg/g (2.038 Bq/kg), 0.034 fg/g (0.0195 Bq/kg), 65.59 fg/g (0.150 Bq/kg), and 12.06 fg/g (0.103 Bq/kg), respectively. PMID:26736181

  17. Ultra-trace determination of (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu by triple quadruple collision/reaction cell-ICP-MS/MS: Establishing a baseline for global fallout in Qatar soil and sediments.

    PubMed

    Amr, Mohamed A; Helal, Abdul-Fattah I; Al-Kinani, Athab T; Balakrishnan, Perumal

    2016-03-01

    The development of practical, fast, and reliable methods for the ultra-trace determination of anthropogenic radionuclides (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu by triple quadruple collision/reaction cell inductively coupled plasma mass spectrometry (CRC-ICP-MS/MS) were investigated in term of its accuracy and precision for producing reliable results. The radionuclides were extracted from 1 kg of the environmental soil samples by concentrated nitric and hydrochloric acids. The leachate solutions were measured directly by triple quadrupole CRC-ICP-MS/MS. For quality assurance, a chemical separation of the concerned radionuclides was conducted and then measured by single quadrupole-ICP-MS. The developed methods were next applied to measure the anthropogenic radionuclides (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu in soil samples collected throughout the State of Qatar. The average concentrations of (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu were 0.606 fg/g (3.364 Bq/kg), 0.619 fg/g (2.038 Bq/kg), 0.034 fg/g (0.0195 Bq/kg), 65.59 fg/g (0.150 Bq/kg), and 12.06 fg/g (0.103 Bq/kg), respectively.

  18. An Internal LLNL Report: Spectroscopic Signature of Aging in (Delta)-Pu(Ga)

    SciTech Connect

    Chung, B W; Fluss, M J; Haslam, J J; Schwartz, A J; Tobin, J G

    2004-12-29

    Resonant Photoemission, a variant of Photoelectron Spectroscopy, has been demonstrated to have sensitivity to aging of Pu samples. The spectroscopic results are correlated with resistivity measurements and are shown to be the fingerprint of mesoscopic or nanoscale internal damage in the Pu physical structure. This means that a spectroscopic signature of internal damage due to aging in Pu has been established.

  19. Transcription factor PU.1 is expressed in white adipose and inhibits adipocyte differentiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PU.1 transcription factor is a critical regulator of hematopoiesis and leukemogenesis. Because PU.1 interacts with transcription factors GATA-2 and C/EBPa, both of which are involved in the regulation of adipogenesis, we investigated whether PU.1 also plays a role in the regulation of adipocyte diff...

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

    SciTech Connect

    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)

  1. EDITORIAL: Proceedings of the 6th Edoardo Amaldi Conference on Gravitational Waves, Bankoku Shinryoukan, Okinawa, Japan, 20-24 June 2005 Proceedings of the 6th Edoardo Amaldi Conference on Gravitational Waves, Bankoku Shinryoukan, Okinawa, Japan, 20-24 June 2005

    NASA Astrophysics Data System (ADS)

    Mio, N.

    2006-04-01

    This issue is published as the Proceedings of the 6th Edoardo Amaldi Conference on Gravitational Waves, held on 20-24 June 2005 at Bankoku Shinryoukan in Okinawa, Japan. Since the first Amaldi conference was held in Frascati in 1994, eleven years have passed and the scale of the conference has grown with the increasing activity in the field of gravitational waves. As the centenary celebration of Einstein's 'miracle year', 2005 was called 'World Year of Physics'. Among his breakthroughs published in 1905, the special theory of relativity is recognized as the most significant revolution in physics, completely changing our views concerning time and space. Ten years later, Einstein proposed the general theory of relativity, by which he predicted the existence of gravitational waves (GWs). At that time, it was only a dream to observe a GW because its effect was so small. Efforts to detect GWs, pioneered by Weber, have continued for almost 40 years, yet their detection remained a dream. However, the presentations at this conference have convinced us that it is no longer a dream. The GW detector projects have made extraordinary advances; in particular, the significant sensitivity improvement of LIGO and the completion of the VIRGO detector mark the beginning of the new era of GW physics. Firm developments in theories and source estimations were also reported. In particular, the data analysis session was very active and various discussions were held. Elaborate experimental techniques were presented, some of them already achieving the requirements for the next generation of detectors, such as Advanced LIGO and LCGT. In addition to the earth-based detectors, many presentations concerning space detectors were contributed; they indicated that space would become the new stage for GW physics and astronomy. This issue brings together the papers which were presented at this exciting conference. The proceedings comprise two volumes; the largest part is published as a volume of

  2. A theoretical study of the ground state and lowest excited states of PuO0/+/+2 and PuO20/+/+2

    SciTech Connect

    Gibson, John K.; La Macchia, Giovanni; Infante, Ivan; Gagliardi, Laura; Raab, Juraj

    2008-12-08

    The ground and excited states of neutral and cationic PuO and PuO2 have been studied with multiconfigurational quantum chemical methods followed by second order perturbation theory, the CASSCF/CASPT2 method. Scalar relativistic effects and spin-orbit coupling have been included in the treatment. As literature values for the ionization energy of PuO2 are in the wide range of ~;;6.6 eV to ~;;10.1 eV, a central goal of the computations was to resolve these discrepancies; the theoretical results indicate that the ionization energy is near the lower end of this range. The calculated ionization energies for PuO, PuO+ and PuO2+ are in good agreement with the experimental values.

  3. Determination of (235)U, (239)Pu, (240)Pu, and (241)Am in a nuclear bomb particle using a position-sensitive α-γ coincidence technique.

    PubMed

    Peräjärvi, Kari A; Ihantola, Sakari; Pöllänen, Roy C; Toivonen, Harri I; Turunen, Jani A

    2011-02-15

    A nuclear bomb particle containing 1.6 ng of Pu was investigated nondestructively with a position-sensitive α detector and a broad-energy HPGe γ-ray detector. An event-mode data acquisition system was used to record the data. α-γ coincidence counting was shown to be well suited to nondestructive isotope ratio determination. Because of the very small background, the 51.6 keV γ rays of (239)Pu and the 45.2 keV γ rays of (240)Pu were identified, which enabled isotopic ratio calculations. In the present work, the (239)Pu/((239)Pu+(240)Pu) atom ratio was determined to be 0.950 ± 0.010. The uncertainties were much smaller than in the previous more conventional nondestructive studies on this particle. Obtained results are also in good agreement with the data from the destructive mass spectrometric studies obtained previously by other investigators.

  4. Temporal record of Pu isotopes in inter-tidal sediments from the northeastern Irish Sea.

    PubMed

    Lindahl, Patric; Worsfold, Paul; Keith-Roach, Miranda; Andersen, Morten B; Kershaw, Peter; Leonard, Kins; Choi, Min-Seok; Boust, Dominique; Lesueur, Patrick

    2011-11-01

    A depth profile of (239)Pu and (240)Pu specific activities and isotope ratios was determined in an inter-tidal sediment core from the Esk Estuary in the northeastern Irish Sea. The study site has been impacted with plutonium through routine radionuclide discharges from the Sellafield nuclear reprocessing plant in Cumbria, NW England. A pronounced sub-surface maximum of ~10 k Bq kg(-1) was observed for (239+240)Pu, corresponding to the peak in Pu discharge from Sellafield in 1973, with a decreasing trend with depth down to ~0.04 k Bq kg(-1) in the deeper layers. The depth profile of (239+240)Pu specific activities together with results from gamma-ray spectrometry for (137)Cs and (241)Am was compared with reported releases from the Sellafield plant in order to estimate a reliable sediment chronology. The upper layers (1992 onwards) showed higher (239+240)Pu specific activities than would be expected from the direct input of annual Sellafield discharges, indicating that the main input of Pu is from the time-integrated contaminated mud patch of the northeastern Irish Sea. The (240)Pu/(239)Pu atom ratios ranged from ~0.03 in the deepest layers to >0.20 in the sub-surface layers with an activity-weighted average of 0.181. The decreasing (240)Pu/(239)Pu atom ratio with depth reflects the changing nature of operations at the Sellafield plant from weapons-grade Pu production to reprocessing spent nuclear fuel with higher burn-up times in the late 1950s. In addition, recent annual (240)Pu/(239)Pu atom ratios in winkles collected during 2003-2008 from three stations along the Cumbrian coastline showed no significant spatial or temporal differences with an overall average of 0.204, which supports the hypothesis of diluted Pu input from the contaminated mud patch.

  5. Temporal record of Pu isotopes in inter-tidal sediments from the northeastern Irish Sea.

    PubMed

    Lindahl, Patric; Worsfold, Paul; Keith-Roach, Miranda; Andersen, Morten B; Kershaw, Peter; Leonard, Kins; Choi, Min-Seok; Boust, Dominique; Lesueur, Patrick

    2011-11-01

    A depth profile of (239)Pu and (240)Pu specific activities and isotope ratios was determined in an inter-tidal sediment core from the Esk Estuary in the northeastern Irish Sea. The study site has been impacted with plutonium through routine radionuclide discharges from the Sellafield nuclear reprocessing plant in Cumbria, NW England. A pronounced sub-surface maximum of ~10 k Bq kg(-1) was observed for (239+240)Pu, corresponding to the peak in Pu discharge from Sellafield in 1973, with a decreasing trend with depth down to ~0.04 k Bq kg(-1) in the deeper layers. The depth profile of (239+240)Pu specific activities together with results from gamma-ray spectrometry for (137)Cs and (241)Am was compared with reported releases from the Sellafield plant in order to estimate a reliable sediment chronology. The upper layers (1992 onwards) showed higher (239+240)Pu specific activities than would be expected from the direct input of annual Sellafield discharges, indicating that the main input of Pu is from the time-integrated contaminated mud patch of the northeastern Irish Sea. The (240)Pu/(239)Pu atom ratios ranged from ~0.03 in the deepest layers to >0.20 in the sub-surface layers with an activity-weighted average of 0.181. The decreasing (240)Pu/(239)Pu atom ratio with depth reflects the changing nature of operations at the Sellafield plant from weapons-grade Pu production to reprocessing spent nuclear fuel with higher burn-up times in the late 1950s. In addition, recent annual (240)Pu/(239)Pu atom ratios in winkles collected during 2003-2008 from three stations along the Cumbrian coastline showed no significant spatial or temporal differences with an overall average of 0.204, which supports the hypothesis of diluted Pu input from the contaminated mud patch. PMID:21911246

  6. Release of Pu isotopes from the Fukushima Daiichi Nuclear Power Plant accident to the marine environment was negligible.

    PubMed

    Bu, Wenting; Fukuda, Miho; Zheng, Jian; Aono, Tatsuo; Ishimaru, Takashi; Kanda, Jota; Yang, Guosheng; Tagami, Keiko; Uchida, Shigeo; Guo, Qiuju; Yamada, Masatoshi

    2014-08-19

    Atmospheric deposition of Pu isotopes from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident has been observed in the terrestrial environment around the FDNPP site; however, their deposition in the marine environment has not been studied. The possible contamination of Pu in the marine environment has attracted great scientific and public concern. To fully understand this possible contamination of Pu isotopes from the FDNPP accident to the marine environment, we collected marine sediment core samples within the 30 km zone around the FDNPP site in the western North Pacific about two years after the accident. Pu isotopes ((239)Pu, (240)Pu, and (241)Pu) and radiocesium isotopes ((134)Cs and (137)Cs) in the samples were determined. The high activities of radiocesium and the (134)Cs/(137)Cs activity ratios with values around 1 (decay corrected to 15 March 2011) suggested that these samples were contaminated by the FDNPP accident-released radionuclides. However, the activities of (239+240)Pu and (241)Pu were low compared with the background level before the FDNPP accident. The Pu atom ratios ((240)Pu/(239)Pu and (241)Pu/(239)Pu) suggested that global fallout and the pacific proving ground (PPG) close-in fallout are the main sources for Pu contamination in the marine sediments. As Pu isotopes are particle-reactive and they can be easily incorporated with the marine sediments, we concluded that the release of Pu isotopes from the FDNPP accident to the marine environment was negligible.

  7. Structural, magnetic, electronic and optical properties of PuC and PuC0.75: A hybrid density functional study

    NASA Astrophysics Data System (ADS)

    Yang, Rong; Tang, Bin; Gao, Tao; Ao, BingYun

    2016-05-01

    We perform first principles calculations to investigate the structural, magnetic, electronic and optical properties of PuC and PuC0.75. Furthermore, we examine the influence of carbon non-stoichiometry on plutonium monocarbide. For the treatment of strongly correlated electrons, the hybrid density functionals like PBE0, Fock-0.25 are used and we compare the results with the generalized gradient approximation (GGA), local density approximation (LDA), LDA + U and experimental ones. The optimized lattice constant a0 = 4.961 Å for PuC in the Fock-0.25 scheme is the most close to the experimental data. The ground states of PuC and PuC0.75 are found to be anti-ferromagnetic. Our results indicate that additional removal of a C atom make lattice contract and new DOS peak appear in the near-Fermi region. We also compute and compare the optical properties of PuC and PuC0.75. The difference in optical properties between PuC and PuC0.75 should also be the influence of carbon vacancies.

  8. Synthesis, structural and thermal studies of Pu(VO3)4: A new vanadate in PuO2-V2O5 system

    NASA Astrophysics Data System (ADS)

    Dahale, N. D.; Achary, S. N.; Sali, S. K.; Keskar, Meera; Phatak, R.; Kannan, S.

    2012-08-01

    A new phase Pu(VO3)4 in PuO2-V2O5 system was prepared by heating an appropriate amount of pre-dried PuO2 and V2O5 at 640 °C. The structural and thermal properties of Pu(VO3)4 were investigated by powder X-ray diffraction and thermogravimetry (TG). Structural analyses revealed that Pu(VO3)4 crystallizes in tetragonal (space group: I41/a) lattice with unit cell parameters, a = 8.4528(2) Å and c = 28.6644(9) Å and is isostructural to metavanadates of thorium and neptunium. Structure shows crystallographically two distinct vanadium atoms V(1) and V(2), one plutonium atom (Pu1) and seven oxygen atoms in the unit cell of Pu(VO3)4. Vanadium atoms form VO4 tetrahedra while plutonium forms PuO8 polyhedra with oxygen atoms. The VO4 units are linked together by sharing apex oxygen atoms and form infinite spiral chains of (VO3)n. Along c-axis, the plutonium atoms are sandwiched between the two layers of (VO3)n chains. TG of Pu(VO3)4 showed thermal stability of the compound up to 700 °C.

  9. Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

    SciTech Connect

    Xun, Luying

    2009-11-20

    The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10^(-10) nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.

  10. Vertical distribution of (241)Pu in the southern Baltic Sea sediments.

    PubMed

    Strumińska-Parulska, Dagmara I

    2014-12-15

    The vertical distribution of plutonium (241)Pu in marine sediments can assist in determining the deposition history and sedimentation process of analyzed regions. In addition, (241)Pu/(239+240)Pu activity ratio could be used as a sensitive fingerprint for radioactive source identification. The present preliminary studies on vertical distribution of (241)Pu in sediments from four regions of the southern Baltic Sea are presented. The distribution of (241)Pu was not uniform and depended on sediment geomorphology and depth as well as location. The highest concentrations of plutonium were found in the surface layers of all analyzed sediments and originated from the Chernobyl accident. PMID:25455816

  11. Vertical distribution of (241)Pu in the southern Baltic Sea sediments.

    PubMed

    Strumińska-Parulska, Dagmara I

    2014-12-15

    The vertical distribution of plutonium (241)Pu in marine sediments can assist in determining the deposition history and sedimentation process of analyzed regions. In addition, (241)Pu/(239+240)Pu activity ratio could be used as a sensitive fingerprint for radioactive source identification. The present preliminary studies on vertical distribution of (241)Pu in sediments from four regions of the southern Baltic Sea are presented. The distribution of (241)Pu was not uniform and depended on sediment geomorphology and depth as well as location. The highest concentrations of plutonium were found in the surface layers of all analyzed sediments and originated from the Chernobyl accident.

  12. AFS-2 FLOWSHEET MODIFICATIONS TO ADDRESS THE INGROWTH OF PU(VI) DURING METAL DISSOLUTION

    SciTech Connect

    Crapse, K.; Rudisill, T.; O'Rourke, P.; Kyser, E.

    2014-07-02

    In support of the Alternate Feed Stock Two (AFS-2) PuO{sub 2} production campaign, Savannah River National Laboratory (SRNL) conducted a series of experiments concluding that dissolving Pu metal at 95°C using a 6–10 M HNO{sub 3} solution containing 0.05–0.2 M KF and 0–2 g/L B could reduce the oxidation of Pu(IV) to Pu(VI) as compared to dissolving Pu metal under the same conditions but at or near the boiling temperature. This flowsheet was demonstrated by conducting Pu metal dissolutions at 95°C to ensure that PuO{sub 2} solids were not formed during the dissolution. These dissolution parameters can be used for dissolving both Aqueous Polishing (AP) and MOX Process (MP) specification materials. Preceding the studies reported herein, two batches of Pu metal were dissolved in the H-Canyon 6.1D dissolver to prepare feed solution for the AFS-2 PuO{sub 2} production campaign. While in storage, UV-visible spectra obtained from an at-line spectrophotometer indicated the presence of Pu(VI). Analysis of the solutions also showed the presence of Fe, Ni, and Cr. Oxidation of Pu(IV) produced during metal dissolution to Pu(VI) is a concern for anion exchange purification. Anion exchange requires Pu in the +4 oxidation state for formation of the anionic plutonium(IV) hexanitrato complex which absorbs onto the resin. The presence of Pu(VI) in the anion feed solution would require a valence adjustment step to prevent losses. In addition, the presence of Cr(VI) would result in absorption of chromate ion onto the resin and could limit the purification of Pu from Cr which may challenge the purity specification of the final PuO{sub 2} product. Initial experiments were performed to quantify the rate of oxidation of Pu(IV) to Pu(VI) (presumed to be facilitated by Cr(VI)) as functions of the HNO{sub 3} concentration and temperature in simulated dissolution solutions containing Cr, Fe, and Ni. In these simulated Pu dissolutions studies, lowering the temperature from near boiling

  13. Electronic structure and phase stability of Pu-Ga alloys

    SciTech Connect

    Gonis, A., LLNL

    1997-03-01

    Plutonium metal has six different crystallographic allotropes from room temperature until it melts just above 600 C. The room-temperature {alpha} phase is monoclinic with 32 atoms per unit cell, (an {alpha} phase with 16 atoms per cell also exists), which is the lowest-symmetry crystal structure known of any pure element. In fact, only the high-temperature {delta} (fcc) phase of Pu possesses one of the traditional close-packed structures. The low-symmetry and small lattice constants of the lowest-temperature phase of the light actinides can be used as an argument for f-bonding in these materials. The large volume increase in Pu in going from the {alpha} to the {delta} phase has been argued on phenomenological grounds to be the result of decreased f-bonding. In addition, XPS data have been obtained for both the {alpha} and the {delta} phases. Both sets of data show the presence of a peak below the Fermi level (EF). This peak is 2.0 eV wide in the {alpha} phase and 3.0 eV wide in the {delta} phase. The XPS intensity calculations (for the two phases) which treat the f-electrons as bonding states agree with the measurements of the {alpha} phase spectra, but not with those of the {delta} phase. The calculated spectrum shows a narrow f-peak pinned at EF instead of the wide f-peak below E{sub F} seen in the XPS spectra. It can be argued that the wide spectra seen experimentally are due to the multiplet structure of localized f-states that do not participate very actively in the bonding. In spite of the difference in the properties of the {alpha} and {delta} phases of Pu (for example {alpha}-Pu is brittle while {delta}-Pu is ductile), it is not difficult to retain either phase by alloying. Indeed, it is often desirable to retain the ductile {delta} phase for engineering purposes, by alloying for example, Pu with Al, Ga, or Si.

  14. Surface-mediated formation of Pu(IV) nanoparticles at the muscovite-electrolyte interface.

    PubMed

    Schmidt, Moritz; Lee, Sang Soo; Wilson, Richard E; Knope, Karah E; Bellucci, Francesco; Eng, Peter J; Stubbs, Joanne E; Soderholm, L; Fenter, P

    2013-12-17

    The formation of Pu(IV)-oxo-nanoparticles from Pu(III) solutions by a surface-enhanced redox/polymerization reaction at the muscovite (001) basal plane is reported, with a continuous increase in plutonium coverage observed in situ over several hours. The sorbed Pu extends >70 Å from the surface with a maximum concentration at 10.5 Å and a total coverage of >9 Pu atoms per unit cell area of muscovite (0.77 μg Pu/cm(2)) (determined independently by in situ resonant anomalous X-ray reflectivity and by ex-situ alpha-spectrometry). The presence of discrete nanoparticles is confirmed by high resolution atomic force microscopy. We propose that the formation of these Pu(IV) nanoparticles from an otherwise stable Pu(III) solution can be explained by the combination of a highly concentrated interfacial Pu-ion species, the Pu(III)-Pu(IV) redox equilibrium, and the strong proclivity of tetravalent Pu to hydrolyze and form polymeric species. These results are the first direct observation of such behavior of plutonium on a naturally occurring mineral, providing insights into understanding the environmental transport of plutonium and other contaminants capable of similar redox/polymerization reactions.

  15. 238Pu: accumulation, tissue distribution, and excretion in Mayak workers after exposure to plutonium aerosols.

    PubMed

    Suslova, Klara G; Sokolova, Alexandra B; Khokhryakov, Viktor V; Miller, Scott C

    2012-03-01

    The alpha spectrometry measurements of specific activity of 238Pu and 239Pu in urine from bioassay examinations of 1,013 workers employed at the radiochemical and plutonium production facilities of the Mayak Production Association and in autopsy specimens of lung, liver, and skeleton from 85 former nuclear workers who died between 1974-2009, are summarized.The accumulation fraction of 238Pu in the body and excreta has not changed with time in workers involved in production of weapons-grade plutonium production (e.g., the plutonium production facility and the former radiochemical facility). The accumulation fraction of 238Pu in individuals exposed to plutonium isotopes at the newer Spent Nuclear Fuel Reprocessing Plant ranged from 0.13% up to 27.5% based on the autopsy data. No statistically significant differences between 238Pu and 239Pu in distribution by the main organs of plutonium deposition were found in the Mayak workers. Based on the bioassay data,the fraction of 238Pu activity in urine is on average 38-69% of the total activity of 238Pu and 239Pu, which correlates with the isotopic composition in workplace air sampled at the Spent Nuclear Fuel Reprocessing Plant. In view of the higher specific activity of 238Pu, the contribution of 238Pu to the total internal dose, particularly in the skeleton and liver, might be expected to continue to increase, and continued surveillance is recommended.

  16. Distinctive and indispensable roles of PU.1 in maintenance of hematopoietic stem cells and their differentiation

    PubMed Central

    Iwasaki, Hiromi; Somoza, Chamorro; Shigematsu, Hirokazu; Duprez, Estelle A.; Iwasaki-Arai, Junko; Mizuno, Shin-ichi; Arinobu, Yojiro; Geary, Kristin; Zhang, Pu; Dayaram, Tajhal; Fenyus, Maris L.; Elf, Shannon; Chan, Susan; Kastner, Philippe; Huettner, Claudia S.; Murray, Richard; Tenen, Daniel G.; Akashi, Koichi

    2005-01-01

    The PU.1 transcription factor is a key regulator of hematopoietic development, but its role at each hematopoietic stage remains unclear. In particular, the expression of PU.1 in hematopoietic stem cells (HSCs) could simply represent “priming” of genes related to downstream myelolymphoid lineages. By using a conditional PU.1 knock-out model, we here show that HSCs express PU.1, and its constitutive expression is necessary for maintenance of the HSC pool in the bone marrow. Bone marrow HSCs disrupted with PU.1 in situ could not maintain hematopoiesis and were outcompeted by normal HSCs. PU.1-deficient HSCs also failed to generate the earliest myeloid and lymphoid progenitors. PU.1 disruption in granulocyte/monocyte-committed progenitors blocked their maturation but not proliferation, resulting in myeloblast colony formation. PU.1 disruption in common lymphoid progenitors, however, did not prevent their B-cell maturation. In vivo disruption of PU.1 in mature B cells by the CD19-Cre locus did not affect B-cell maturation, and PU.1-deficient mature B cells displayed normal proliferation in response to mitogenic signals including the cross-linking of surface immunoglobulin M (IgM). Thus, PU.1 plays indispensable and distinct roles in hematopoietic development through supporting HSC self-renewal as well as commitment and maturation of myeloid and lymphoid lineages. PMID:15914556

  17. Aggressive acute myeloid leukemia in PU.1/p53 double-mutant mice.

    PubMed

    Basova, P; Pospisil, V; Savvulidi, F; Burda, P; Vargova, K; Stanek, L; Dluhosova, M; Kuzmova, E; Jonasova, A; Steidl, U; Laslo, P; Stopka, T

    2014-09-25

    PU.1 downregulation within hematopoietic stem and progenitor cells (HSPCs) is the primary mechanism for the development of acute myeloid leukemia (AML) in mice with homozygous deletion of the upstream regulatory element (URE) of PU.1 gene. p53 is a well-known tumor suppressor that is often mutated in human hematologic malignancies including AML and adds to their aggressiveness; however, its genetic deletion does not cause AML in mouse. Deletion of p53 in the PU.1(ure/ure) mice (PU.1(ure/ure)p53(-/-)) results in more aggressive AML with shortened overall survival. PU.1(ure/ure)p53(-/-) progenitors express significantly lower PU.1 levels. In addition to URE deletion we searched for other mechanisms that in the absence of p53 contribute to decreased PU.1 levels in PU.1(ure/ure)p53(-/-) mice. We found involvement of Myb and miR-155 in downregulation of PU.1 in aggressive murine AML. Upon inhibition of either Myb or miR-155 in vitro the AML progenitors restore PU.1 levels and lose leukemic cell growth similarly to PU.1 rescue. The MYB/miR-155/PU.1 axis is a target of p53 and is activated early after p53 loss as indicated by transient p53 knockdown. Furthermore, deregulation of both MYB and miR-155 coupled with PU.1 downregulation was observed in human AML, suggesting that MYB/miR-155/PU.1 mechanism may be involved in the pathogenesis of AML and its aggressiveness characterized by p53 mutation.

  18. Characterization of Pu concentration and its isotopic composition in soils of Gansu in northwestern China.

    PubMed

    Zheng, Jian; Yamada, Masatoshi; Wu, Fengchang; Liao, Haiqing

    2009-01-01

    The total 239+240Pu activities and 240Pu/239Pu atom ratios in surface soil samples (0-5cm) in the Kumtag Desert in western Gansu Province, and in a soil core sample in Lanzhou were investigated using a sector-field ICP-MS. In the surface soil samples, 239+240Pu activities in fine particles (<150microm) were 1.3-2.1 times of those in coarse particles (150microm-1mm) which ranged from 0.005 to 0.157mBq/g. Atom ratios of 240Pu/239Pu in the surface soils ranged from 0.168 to 0.192 with a mean of 0.182+/-0.008. The mean ratio was similar to the typical global fallout value although the Kumtag Desert was believed to have received close-in fallout derived from Chinese nuclear weapons tests mainly conducted in the 1970s. Furthermore, the mean 240Pu/239Pu atom ratio observed in the soil core sample in Lanzhou was similar to the typical global fallout value. In the soil core sample, 239+240Pu activities in the various layers ranged from 0.012 to 0.23mBq/g, and the inventory of 239+240Pu (32.4Bq/m2, 0-23cm) was slightly lower than that expected from global fallout (42Bq/m2) at the same latitude. Rapid downward migration of Pu isotopes was observed in Lanzhou soil core sample layers. The contribution of the 10-cm deep top layers of surface soils to total inventory was only 17%, while the contribution of deeper layers (10-23cm) was as high as 83%. The 239+240Pu activity levels and 240Pu/239Pu atom ratios in soils in Gansu Province, China are similar to those in atmospheric deposition samples collected in the spring in recent years in Japan.

  19. Design of a Pu-238 Waste Incineration Process

    SciTech Connect

    Charlesworth, D.L.

    2001-05-29

    Combustible Pu-238 waste is generated as a result of normal operation and decommissioning activity at the Savannah River Plant and is being retrievably stored there. As part of the long-term plan to process the stored waste and current waste in preparation for future disposition, a Pu-238 incineration process is being cold-tested at Savannah River Laboratory (SRL). The incineration process consists of a continuous-feed preparation system, a two-stage, electrically fired incinerator, and a filtration off-gas system. Process equipment has been designed, fabricated, and installed for nonradioactive testing and cold run-in. Design features to maximize the ability to remotely maintain the equipment were incorporated into the process. Interlock, alarm, and control functions are provided by a programmable controller. Cold testing is scheduled to be completed in 1986.

  20. Np and Pu Sorption to Manganese Oxide Minerals

    SciTech Connect

    Zhao, P; Johnson, M R; Roberts, S K; Zavarin, M

    2005-08-30

    Manganese oxide minerals are a significant component of the fracture lining mineralogy at Yucca Mountain (Carlos et al., 1993) and within the tuff-confining unit at Yucca Flat (Prothro, 1998), Pahute Mesa (Drellack et al., 1997), and other locations at the Nevada Test Site (NTS). Radionuclide sorption to manganese oxide minerals was not included in recent Lawrence Livermore National Laboratory (LLNL) hydrologic source term (HST) models which attempt to predict the migration behavior of radionuclides away from underground nuclear tests. However, experiments performed for the Yucca Mountain Program suggest that these minerals may control much of the retardation of certain radionuclides, particularly Np and Pu (Triay et al., 1991; Duff et al., 1999). As a result, recent HST model results may significantly overpredict radionuclide transport away from underground nuclear tests. The sorption model used in HST calculations performed at LLNL includes sorption to iron oxide, calcite, zeolite, smectite, and mica minerals (Zavarin and Bruton 2004a; 2004b). For the majority of radiologic source term (RST) radionuclides, we believe that this accounts for the dominant sorption processes controlling transport. However, for the case of Np, sorption is rather weak to all but the iron and manganese oxides (Figure 1). Thus, we can expect to significantly reduce predicted Np transport by accounting for Np sorption to manganese oxides. Similarly, Pu has been shown to be predominantly associated with manganese oxides in Yucca Mountain fractured tuffs (Duff et al., 1999). Recent results on colloid-facilitated Pu transport (Kersting and Reimus, 2003) also suggest that manganese oxide coatings on fracture surfaces may compete with colloids for Pu, thus reducing the effects of colloid-facilitated Pu transport (Figure 1b). The available data suggest that it is important to incorporate Np and Pu sorption to manganese oxides in reactive transport models. However, few data are available for

  1. Effects of aqueous extracts of raw pu-erh tea and ripened pu-erh tea on proliferation and differentiation of 3T3-L1 preadipocytes.

    PubMed

    Cao, Zhen-Hui; Yang, Hui; He, Zhan-Long; Luo, Cheng; Xu, Zhi-Qiang; Gu, Da-Hai; Jia, Jun-Jing; Ge, Chang-Rong; Lin, Qiu-Ye

    2013-08-01

    Pu-erh tea has shown anti-obesity effects but little is known about its effect on proliferation and differentiation of preadipocytes. This study investigated the effects of the aqueous extracts of raw pu-erh tea and ripened pu-erh tea on proliferation and differentiation of murine 3T3-L1 preadiopocytes. We examined dose and time effects of both aqueous extracts on proliferation of 3T3-L1 preadipocytes. The contents of triglycerides in cytoplasm and the mRNA expression of critical transcriptional factors involved in differentiation were determined. Cytotoxicity and apoptosis rate of preadipocytes by pu-erh tea extracts treatment were test for toxic and pro-apoptotic effects. Both aqueous extracts of pu-erh tea inhibited the proliferation of 3T3-L1 preadipocytes at the selected time points. At lower concentration of raw pu-erh tea extracts (less than 300 µg/ml) and ripened pu-erh tea extracts (less than 350 µg/ml), no significant cytotoxic and pro-apoptotic were observed. Ripened pu-erh tea was more effective with lower IC50 than raw pu-erh tea. Both extracts suppressed the differentiation and down-regulated the gene expression of peroxisome proliferator-activated receptor-γ and CCAAT/enhancer binding proteins-α. Therefore, these results indicate that both aqueous extracts of pu-erh tea can inhibit proliferation and differentiation with ripened pu-erh tea more potent. Polyphenol rich in both extracts may play a role in the inhibition of proliferation and differentiation of 3T3-L1 preadipocytes.

  2. Slow Neutron Velocity Spectrometer Transmission Studies Of Pu

    DOE R&D Accomplishments Database

    Havens, W. W. Jr.; Melkonian, E.; Rainwater, L. J.; Levin, M.

    1951-05-28

    The slow neutron transmission of several samples of Pu has been investigated with the Columbia Neutron Velocity Spectrometer. Data are presented in two groups, those covering the energy region from 0 to 6 ev, and those covering the region above 6 ev. Below 6 ev the resolution was relatively good, and a detailed study of the cross section variation was made. Work above 6 ev consisted of merely locating levels and obtaining a rough idea of their strengths.

  3. Characterization of Pu-238 heat source granule containment

    SciTech Connect

    Richardson Ii, P D; Thronas, D L; Romero, J P; Sandoval, F E; Neuman, A D; Duncan, W S

    2008-01-01

    The Milliwatt Radioisotopic Thermoelectric Generator (RTG) provides power for permissive-action links. These nuclear batteries convert thermal energy to electrical energy using a doped silicon-germanium thermopile. The thermal energy is provided by a heat source made of {sup 238}Pu, in the form of {sup 238}PuO{sub 2} granules. The granules are contained in 3 layers of encapsulation. A thin T-111 liner surrounds the {sup 238}PuO{sub 2} granules and protects the second layer (strength member) from exposure to the fuel granules. The T-111 strength member contains the fuel under impact condition. An outer clad of Hastelloy-C protects the T-111 from oxygen embrittlement. The T-111 strength member is considered the critical component in this {sup 238}PuO{sub 2} containment system. Any compromise in the strength member is something that needs to be characterized. Consequently, the T-111 strength member is characterized upon it's decommissioning through Scanning Electron Microscopy (SEM), and Metallography. SEM is used in 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 photomicrographs. SEM may further be used to examine polished Metallography mounts to characterize elements using the SEM mode of Energy Dispersive X-ray Spectroscopy (EDS). This paper describes the characterization of the metallurgical condition of decommissioned RTG heat sources.

  4. Application of PSA to storage of Pu at SRS

    SciTech Connect

    Lux, C.R.

    1995-12-01

    Pu is stored in a wide variety of physical forms and containers at the Savannah River Site (SRS). Probabilistic Safety Analysis (PSA) techniques are used to determine the risk associated with each of these storage modes and assist in identification of the controls necessary to minimize the risk. One storage method involves solids in exposed drum storage where the drums are vulnerable to external events, natural phenomena, and release of material due to weathering of the containers. Another storage method may involve liquids being processed inside the canyon facilities where the greatest risks are not from external events but from process upsets. PSA techniques have been particularly useful in the evaluation of criticality situations concerning Pu processing and storage. The applications include ``normal`` operating situations, problems following a seismic event, and the identification of potential problems during the decontamination and decommissioning of a facility. In this paper I would like to discuss two specific examples of the use of PSA techniques. The first involves the analysis of potential accidents in a Pu receipt and storage facility. The second example involves processing solutions that have the potential for experiencing an uncontrolled ``red oil`` reaction.

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

    SciTech Connect

    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. Mass spectrometric study on the vaporization of ternary compounds PuMC 2(M = Fe, Co, Ni)

    NASA Astrophysics Data System (ADS)

    Suzuki, Yasufumi; Arai, Yasuo; Ohmichi, Toshihiko; Sasayama, Tatsuo

    1983-04-01

    The thermochemical properties of ternary compounds PuFeC 2, PuCoC 2 and PuNiC 2 were investigated in the temperature range 1420-1853 K by means of the Knudsen effusion mass spectrometric technique. The peritectic reactions at 1650, 1610 and 1670 K were suggested for these three compounds, respectively. Below the peritectic temperature, their vaporization process was incongruent, as the vapor pressures of Fe, Co and Ni were much higher than that of Pu. The free energies of formation of PuFeC 2, PuCoC 2 and PuNiC 2 have been determined from the vapor pressure data.

  7. Determination of Pu isotopes and 241Am in a reference fallout material using SF-ICP-MS.

    PubMed

    Zheng, Jian; Zhang, Yongsan; Yamada, Masatoshi; Wu, Fengchang; Igarashi, Yasuhito; Hirose, Katsumi

    2011-07-01

    This paper reports on the characterisation of activities of Pu and (241)Am, and Pu isotopic composition in a reference fallout material prepared by the Meteorological Research Institute (MRI), Japan, from samples collected at 14 stations throughout Japan in 1963-1979. The acid leaching and total digestion were used to compare whether there is difference in Pu and (241)Am activities and Pu isotopic composition between these two methods. The results of activities of (239+240)Pu and (241)Pu, and Pu isotopic composition have been reported in the previous work (Sci. Total Environ. 2010, 408, 1139-1144). In this study, the (241)Am activity and (241)Am/(239+240)Pu activity ratio in the reference fallout material are reported, and the usefulness of Pu atom ratios and (241)Am/(239+240)Pu activity ratio for source identification is discussed.

  8. Distribution characteristics of ¹³⁷Cs, Pu isotopes and ²⁴¹Am in soil in Korea.

    PubMed

    Lee, S H; Oh, J S; Lee, J M; Lee, K B; Park, T S; Lujaniene, G; Valiulis, D; Sakalys, J

    2013-11-01

    Cesium-137, Plutonium isotopes and (241)Am were studied in soil samples collected from Korea between 2006 and 2008 to provide information on the distribution and origin of Pu isotopes and (241)Am. The vertical profiles of radionuclides showed higher activity concentrations at the surface layer and then gradually decreased with depth. A good correlation between (137)Cs and (239,240)Pu was observed, whereas a poor relationship between (137)Cs and (241)Am was found. The (238)Pu/(239,240)Pu, (241)Am/(239,240)Pu and (239,240)Pu/(137)Cs activity ratios were concordant to those of the global fallout ratios. Furthermore, the atomic ratios of (240)Pu/(239)Pu in the samples provided the information of Pu depositional history and the origin of Pu isotopes in Korea.

  9. Measurement of 240Pu/239Pu isotopic ratios in soils from the Marshall Islands using ICP-MS.

    PubMed

    Muramatsu, Y; Hamilton, T; Uchida, S; Tagami, K; Yoshida, S; Robison, W

    2001-10-20

    Nuclear weapons tests conducted by the United States in the Marshall Islands produced significant quantities of regional or tropospheric fallout contamination. Here we report on some preliminary inductively coupled plasma-mass spectrometry (ICP-MS) measurements of plutonium isolated from seven composite soil samples collected from Bikini, Enewetak and Rongelap Atolls in the northern Marshall Islands. These data show that 240Pu/239Pu isotopic signatures in surface soils from the Marshall Island vary significantly and could potentially be used to help quantify the range and extent of fallout deposition (and associated impacts) from specific weapons tests. 137Cs and 60Co were also determined on the same set of soil samples for comparative purposes. PMID:11669263

  10. Carcinogenesis From Inhaled (PuO2)-Pu-239 in Beagles: Evidence for Radiation Homeostasis at Low Doses?

    SciTech Connect

    Fisher, Darrell R.; Weller, Richard E.

    2010-09-01

    From the early 1970s to the late 1980s, Pacific Northwest National Laboratory conducted life-span studies in beagle dogs on the biological effects of inhaled plutonium (239PuO2, 238PuO2, and 239Pu[NO3]4) to help predict risks associated with accidental intakes in workers. Years later, the purpose of the present follow-up study is to reassess the dose-response relationship for lung cancer induction in the 239PuO2 dogs compared to controls, with particular focus on the dose-response at low lung doses. A 239PuO2 aerosol (2.3 μm AMAD, 1.9 μm GSD) was administered to six groups of 20 young (18-month old) beagle dogs (10 males and 10 females) by inhalation at six different activity levels, as previously described in Laboratory reports. Control dogs were sham-exposed. In dose level 1, initial pulmonary lung depositions were 130 ± 48 Bq (3.5 ± 1.3 nCi), corresponding to 1 Bq g-1 lung tissue (0.029 ± 0.001 nCi g-1. Groups 2 through 6 received initial lung depositions (mean values) of 760, 2724, 10345, 37900, and 200000 Bq (22, 79, 300, 1100, and 5800 nCi) 239PuO2, respectively. For each dog, the absorbed dose to lungs was calculated from the initial lung burden and the final lung burden at time of death and lung mass, assuming a single, long-term retention function. Insoluble plutonium oxide exhibited long retention times in the lungs. Increased dose-dependent mortality due to lung cancer (bronchiolar-alveolar carcinoma, adenocarcinoma, epidermoid carcinoma) and radiation pneumonitis (highest exposures group) was observed in dogs exposed to 239PuO2. Calculated lung doses ranged from a few cGy in early-sacrificed dogs to 7764 cGy in dogs that experienced early deaths from radiation pneumonitis. Data were regrouped by lifetime lung dose and plotted as a function of lung tumor incidence. Lung tumor incidence in controls and zero-dose exposed dogs was 18% (5/28). However, no lung tumors were observed in 16 dogs with the lowest lung doses (8 to 22 cGy, mean 14.4 ± 7.6 c

  11. Vertical distribution and migration of global fallout Pu in forest soils in southwestern China.

    PubMed

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Uchida, Shigeo

    2014-10-01

    Soil samples collected in southwestern China were analyzed for Pu isotopes. The (240)Pu/(239)Pu atom ratios were around 0.18, which indicated the dominant source of global fallout. Consistent sub-surface maximums followed by exponential decline of (239+240)Pu activities in the soil cores were observed. Most of the Pu has still remained in the 0-10 cm layers since its deposition. Convection velocities and dispersion coefficients for Pu migration in the soils were estimated by the convection-dispersion equation (CDE) model. The effective convection velocities and effective dispersion coefficients ranged from 0.05 to 0.11 cm/y and from 0.06 to 0.29 cm(2)/y, respectively. Other factors that control the vertical migration of Pu in soil besides precipitation, soil particle size distribution and organic matter were suggested. Long-term migration behaviors of Pu in the soils were simulated. The results provide the Pu background baseline for further environmental monitoring and source identification of non-global fallout Pu inputs in the future.

  12. Dissolution characteristics of Pu-contaminated soils and sediments in lung serum simulant solution.

    PubMed

    Lee, S Y; Bondietti, E A; Tamura, T

    1982-11-01

    Dissolution characteristics of Pu from contaminated Nevada Test Site (NTS) and Rocky Flats (RF) soils, and Mound Laboratory (ML) and Oak Ridge National Laboratory (ORNL) sediments in lung serum simulant solution at 37 degrees C were investigated. The dissolved Pu concentration had reached a maximum within a day of equilibration and the percent dissolved Pu at the maximum was 0.70 (RF), 0.43 (ML), 0.02 (ORNL), and 0.02 (NTS). The Pu concentrations of the RF, ML and ORNL samples in the successively extracted solutions decreased drastically but the concentration in the NTS soil extracts did not change significantly. The differences in Pu dissolution among the samples were caused by the differences in the total Pu concentration, particle size distribution, and chemical nature of Pu in contaminated soils and sediments. The higher solubility of the particulate Pu form in the RF soil relative to the ORNL sediment contaminated by dissolved Pu suggests that contamination source alone can not explain the observed differences. Variation of Pu solubility among the samples indicates that a single solubility class for dose assessment use may not be appropriate, particularly if one attempts to make comparative assessments among different sites. PMID:7152928

  13. Mechanisms of in vivo binding site selection of the hematopoietic master transcription factor PU.1.

    PubMed

    Pham, Thu-Hang; Minderjahn, Julia; Schmidl, Christian; Hoffmeister, Helen; Schmidhofer, Sandra; Chen, Wei; Längst, Gernot; Benner, Christopher; Rehli, Michael

    2013-07-01

    The transcription factor PU.1 is crucial for the development of many hematopoietic lineages and its binding patterns significantly change during differentiation processes. However, the 'rules' for binding or not-binding of potential binding sites are only partially understood. To unveil basic characteristics of PU.1 binding site selection in different cell types, we studied the binding properties of PU.1 during human macrophage differentiation. Using in vivo and in vitro binding assays, as well as computational prediction, we show that PU.1 selects its binding sites primarily based on sequence affinity, which results in the frequent autonomous binding of high affinity sites in DNase I inaccessible regions (25-45% of all occupied sites). Increasing PU.1 concentrations and the availability of cooperative transcription factor interactions during lineage differentiation both decrease affinity thresholds for in vivo binding and fine-tune cell type-specific PU.1 binding, which seems to be largely independent of DNA methylation. Occupied sites were predominantly detected in active chromatin domains, which are characterized by higher densities of PU.1 recognition sites and neighboring motifs for cooperative transcription factors. Our study supports a model of PU.1 binding control that involves motif-binding affinity, PU.1 concentration, cooperativeness with neighboring transcription factor sites and chromatin domain accessibility, which likely applies to all PU.1 expressing cells.

  14. Technology for Teachers. 6th Edition.

    ERIC Educational Resources Information Center

    Volker, Roger; Simonson, Michael

    This book helps teachers learn how to use and make educational media, covering traditional and new media such as computer laboratories, authentic assessment, theory bases, and hypermedia. Chapter topics progress from simple to complex. Each chapter includes clearly stated behavioral objectives that provide a study guide for students and can serve…

  15. Elementary Science Guide -- 6th Grade.

    ERIC Educational Resources Information Center

    Wieland, Anne; And Others

    Presented is a resource book to be used with instructional kits for elementary school science students, grade 6. The individual units at this grade level are based on curriculum which has been developed by the National Science Foundation in the 1960s and revised to meet student and teacher identified needs in Anchorage, Alaska. Six units are…

  16. Safety Report - Experiments 999 and 891 Muon Spin Relaxation in Pu and Pu-based Heavy Fermion Materials

    SciTech Connect

    Fluss, M; Heffner, R; Morris, G

    2004-04-23

    Experiment E999 proposes to carry out conventional muon spin relaxation ({mu}SR) measurements on solid samples of plutonium and plutonium alloys. Experiment 891 will be involved with {mu}SR experiments on PuCoGa{sub 5} and related Pu-based superconductors. Other than a dedicated cryostat to be provided by Los Alamos and a pumping station provided by Livermore, the experiments will use existing {mu}SR User Facility spectrometers and associated equipment such as detectors and electronics. The main topics of this report are therefore (1) the passivation of the samples with a polymer coating, (2) the design, fabrication and testing of a sealed titanium sample secondary encapsulation cell, (3) the transport of samples to and from TRIUMF and (4) the related on-site procedures for the safe handling of the encapsulated samples. Because both E999 and E891 share the same equipment and Pu-safety related issues, we are submitting a single safety report for both experiments.

  17. A method of measurement of (239)Pu, (240)Pu, (241)Pu in high U content marine sediments by sector field ICP-MS and its application to Fukushima sediment samples.

    PubMed

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Aono, Tatsuo; Tazoe, Hirofumi; Tagami, Keiko; Uchida, Shigeo; Yamada, Masatoshi

    2014-01-01

    An accurate and precise analytical method is highly needed for the determination of Pu isotopes in marine sediments for the long-term marine environment monitoring that is being done since the Fukushima Dai-ichi Nuclear Power Plant accident. The elimination of uranium from the sediment samples needs to be carefully checked. We established an analytical method based on anion-exchange chromatography and SF-ICP-MS in this work. A uranium decontamination factor of 2 × 10(6) was achieved, and the U concentrations in the final sample solutions were typically below 4 pg mL(-1), thus no extra correction of (238)U interferences from the Pu spectra was needed. The method was suitable for the analysis of (241)Pu in marine sediments using large sample amounts (>10 g). We validated the method by measuring marine sediment reference materials and our results agreed well with the certified and the literature values. Surface sediments and one sediment core sample collected after the nuclear accident were analyzed. The characterization of (241)Pu/(239)Pu atom ratios in the surface sediments and the vertical distribution of Pu isotopes showed that there was no detectable Pu contamination from the nuclear accident in the marine sediments collected 30 km off the plant site. PMID:24328266

  18. A method of measurement of (239)Pu, (240)Pu, (241)Pu in high U content marine sediments by sector field ICP-MS and its application to Fukushima sediment samples.

    PubMed

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Aono, Tatsuo; Tazoe, Hirofumi; Tagami, Keiko; Uchida, Shigeo; Yamada, Masatoshi

    2014-01-01

    An accurate and precise analytical method is highly needed for the determination of Pu isotopes in marine sediments for the long-term marine environment monitoring that is being done since the Fukushima Dai-ichi Nuclear Power Plant accident. The elimination of uranium from the sediment samples needs to be carefully checked. We established an analytical method based on anion-exchange chromatography and SF-ICP-MS in this work. A uranium decontamination factor of 2 × 10(6) was achieved, and the U concentrations in the final sample solutions were typically below 4 pg mL(-1), thus no extra correction of (238)U interferences from the Pu spectra was needed. The method was suitable for the analysis of (241)Pu in marine sediments using large sample amounts (>10 g). We validated the method by measuring marine sediment reference materials and our results agreed well with the certified and the literature values. Surface sediments and one sediment core sample collected after the nuclear accident were analyzed. The characterization of (241)Pu/(239)Pu atom ratios in the surface sediments and the vertical distribution of Pu isotopes showed that there was no detectable Pu contamination from the nuclear accident in the marine sediments collected 30 km off the plant site.

  19. 238Pu, 239,240Pu, 241Am, 90Sr and 137Cs in soils around nuclear research centre Rez, near Prague.

    PubMed

    Hölgye, Z; Schlesingerová, E; Tecl, J; Filgas, R

    2004-01-01

    Forty-four soil samples were taken around the nuclear research centre Rez, near Prague. The mean activity concentrations of 238Pu, 239,240Pu, 241Am, 90Sr and 137Cs in uncultivated soil were 0.010, 0.26, 0.12, 2.7 and 23 Bq.kg(-1), respectively. Contents of radionuclides in cultivated soil were lower and in forest soil higher than in uncultivated soil. The mean activity ratios of 238Pu/239,240Pu, 241Am/239,240Pu, 90Sr/239,240Pu and 239,240Pu/137Cs in uncultivated soil were 0.041, 0.47, 10.9 and 0.013, respectively. The mean activity ratios in cultivated and forest soils were close to the values given above. It follows from the results that the source of 239,240Pu, 90Sr and 137Cs in the studied area is deposition from atmospheric nuclear tests, in the case of 137Cs also deposition from Chernobyl accident. The contribution of the research centre effluents was not proved for these radionuclides. Increased activity ratio of 241Am/239,240Pu indicates the presence of 241Am in the soils studied emanating from sources other than nuclear tests. Uniform distribution of the 241Am/239,240Pu activity ratio around the nuclear research centre and the absence of an area with evidently higher activity ratio, including at sites lying in the main wind direction, suggest that the additional activity of 241Am does not originate from the nuclear research centre. The additional source might be the deposition following the Chernobyl accident.

  20. Characterization of ^{239,240}Pu Radionuclide Adsorption to Soil Particles and Mineral Dust Aerosols

    NASA Astrophysics Data System (ADS)

    Tatro, D. P.; Arimoto, R.; McMillan, N. J.; Barnes, M.

    2006-12-01

    The release of ^{239,240}Pu into the environment by nuclear weapons testing 50 years ago initiated the cyclic mobilization of Pu-contaminated soil particles via the resuspension of dust resulting in a widespread distribution of Pu and other radionuclides. It is unclear what enables the aeolian transport of Pu in the environment; plausible hypotheses of Pu binding to dust and soil particles include Pu adsorption to iron oxides/hydroxides, organic acids, or silicate minerals such as clays. To investigate the connections between surface soils, dust and radionuclides, samples of soil and/or dust were collected from the Project Gnome Site in Eddy County, NM, the Jemez Mountains near Los Alamos, NM, and two 50-year old attics and wind-blown dust in Big Spring, TX. This study tests the hypothesis that Pu is adsorbed onto Fe oxides and hydroxides that coat dust/soil particles. The samples are generally low in organic carbon (0.2 - 4.8%, except for the unburned Los Alamos sample at 9.4%), as measured by LOI (Loss On Ignition) at 360 °C. The citrate-bicarbonate-dithionite method (CDB) of Fe oxide removal, first proposed by Mehra and Jackson in 1960, was used to selectively extract Fe oxides from the samples while leaving silicate Fe intact. Chemical digestion of each sample creates two fractions, the extracted supernatant and a solid pellet residue. If the Pu were associated with Fe oxides, then Fe and Pu should both be selectively removed from the bulk sample during the CBD process, leaving the pellet depleted in Fe and Pu and the supernatant enriched. For Fe, this was confirmed by scanning electron microscope and petrographic analyses. Preliminary radiochemical analyses of Pu activity also verify this hypothesis. Pu activity is significantly lower in pellets than bulk samples (Pu activitypellet/Pu activitybulk average = 0.07, range 0.02-0.12); Pu activity in supernatants is significantly higher than in bulk samples (Pu activitysupernatant/Pu activitybulk average = 4

  1. Bacterial Pu(V) reduction in the absence and presence of Fe(III)-NTA: modeling and experimental approach.

    PubMed

    Deo, Randhir P; Rittmann, Bruce E; Reed, Donald T

    2011-09-01

    Plutonium (Pu), a key contaminant at sites associated with the manufacture of nuclear weapons and with nuclear-energy wastes, can be precipitated to "immobilized" plutonium phases in systems that promote bioreduction. Ferric iron (Fe(3+)) is often present in contaminated sites, and its bioreduction to ferrous iron (Fe(2+)) may be involved in the reduction of Pu to forms that precipitate. Alternately, Pu can be reduced directly by the bacteria. Besides Fe, contaminated sites often contain strong complexing ligands, such as nitrilotriacetic acid (NTA). We used biogeochemical modeling to interpret the experimental fate of Pu in the absence and presence of ferric iron (Fe(3+)) and NTA under anaerobic conditions. In all cases, Shewanella alga BrY (S. alga) reduced Pu(V)(PuO(2) (+)) to Pu(III), and experimental evidence indicates that Pu(III) precipitated as PuPO(4(am).) In the absence of Fe(3+) and NTA, reduction of PuO(2) (+) was directly biotic, but modeling simulations support that PuO(2) (+) reduction in the presence of Fe(3+) and NTA was due to an abiotic stepwise reduction of PuO(2) (+) to Pu(4+), followed by reduction of Pu(4+) to Pu(3+), both through biogenically produced Fe(2+). This means that PuO(2) (+) reduction was slowed by first having Fe(3+) reduced to Fe(2+). Modeling results also show that the degree of PuPO(4(am)) precipitation depends on the NTA concentration. While precipitation out-competes complexation when NTA is present at the same or lower concentration than Pu, excess NTA can prevent precipitation of PuPO(4(am)). PMID:21234648

  2. Activation of transcription by PU.1 requires both acidic and glutamine domains.

    PubMed Central

    Klemsz, M J; Maki, R A

    1996-01-01

    The B-lymphocyte- and macrophage-specific transcription factor PU.1 is a member of the ets family of proteins. To understand how PU.1 functions as a transcription factor, we initiated a series of experiments to define its activation domain. Using deletion analysis, we showed that the activation domain of PU.1 is located in the amino-terminal half of the protein. Within this region, we identified three acidic subdomains and one glutamine-rich subdomain. The deletion of any of these subdomains resulted in a significant loss in the ability of PU.1 to transactivate in cotransfection studies. Amino acid substitution analysis showed that the activation of transcription by PU.1 requires acidic residues between amino acids 7 and 74 and a group of glutamine residues between amino acids 75 and 84. These data show that PU.1 contains two types of known activation domains and that both are required for maximal transactivation. PMID:8524320

  3. Soft X-ray Studies of Pu Electronic Structure: Past Lessons and Future Directions

    SciTech Connect

    Tobin, J G; Yu, S W

    2008-02-07

    Photoelectron Spectroscopy (PES) and X-ray Absorption Spectroscopy (XAS, Figure 1) have contributed greatly to our improved understanding of Pu electronic structure. From these and related measurements, the following has been determined: (1) The Pu 5f spin-orbit splitting is large; (2) The number of Pu5f electrons is near 5; and (3) The Pu 5f spin-orbit splitting effect dominates 5f itineracy. Significant questions remain concerning the nature of Pu electronic structure. Perhaps the missing piece of the puzzle is the direct experimental determination of the unoccupied electronic structure using high energy inverse photoelectron spectroscopy or Bremstrahlung Isochromat Spectroscopy (BIS). Past BIS studies of Th and U indicate the feasibility and utility of Pu studies.

  4. The transcription factor PU.1 promotes alternative macrophage polarization and asthmatic airway inflammation.

    PubMed

    Qian, Feng; Deng, Jing; Lee, Yong Gyu; Zhu, Jimmy; Karpurapu, Manjula; Chung, Sangwoon; Zheng, Jun-Nian; Xiao, Lei; Park, Gye Young; Christman, John W

    2015-12-01

    The transcription factor PU.1 is involved in regulation of macrophage differentiation and maturation. However, the role of PU.1 in alternatively activated macrophage (AAM) and asthmatic inflammation has yet been investigated. Here we report that PU.1 serves as a critical regulator of AAM polarization and promotes the pathological progress of asthmatic airway inflammation. In response to the challenge of DRA (dust mite, ragweed, and Aspergillus) allergens, conditional PU.1-deficient (PU/ER(T)(+/-)) mice displayed attenuated allergic airway inflammation, including decreased alveolar eosinophil infiltration and reduced production of IgE, which were associated with decreased mucous glands and goblet cell hyperplasia. The reduced asthmatic inflammation in PU/ER(T)(+/-) mice was restored by adoptive transfer of IL-4-induced wild-type (WT) macrophages. Moreover, after treating PU/ER(T)(+/-) mice with tamoxifen to rescue PU.1 function, the allergic asthmatic inflammation was significantly restored. In vitro studies demonstrate that treatment of PU.1-deficient macrophages with IL-4 attenuated the expression of chitinase 3-like 3 (Ym-1) and resistin-like molecule alpha 1 (Fizz-1), two specific markers of AAM polarization. In addition, PU.1 expression in macrophages was inducible in response to IL-4 challenge, which was associated with phosphorylation of signal transducer and activator of transcription 6 (STAT6). Furthermore, DRA challenge in sensitized mice almost abrogated gene expression of Ym-1 and Fizz-1 in lung tissues of PU/ER(T)(+/-) mice compared with WT mice. These data, all together, indicate that PU.1 plays a critical role in AAM polarization and asthmatic inflammation.

  5. Removal of Pu238 from Neptunium Solution by Anion Exchange

    SciTech Connect

    KYSER, EDWARD

    2003-12-01

    A new anion flowsheet for use in HB-Line was tested in the lab with Reillex{trademark} HPQ for removal of Pu{sup 238} contamination from Np. Significant rejection of Pu{sup 238} was observed by washing with 6 to 12 bed volumes (BV) of reductive wash containing reduced nitric acid concentration along with both ferrous sulfamate (FS) and hydrazine. A shortened-height column was utilized in these tests to match changes in the plant equipment. Lab experiments scaled to plant batch sizes of 1500 to 2200 g Np were observed with modest losses for up-flow washing. Down-flow washing was observed to have high losses. The following are recommended conditions for removing Pu{sup 238} from Np solutions by anion exchange in HB-Line: (1) Feed conditions: Up-flow 6.4-8 M HNO{sub 3}, 0.02 M hydrazine, 0.05 M excess FS, less than 5 days storage of solution after FS addition. (2) Reductive Wash conditions: Up-flow 6-12 BV of 6.4 M HNO{sub 3}, 0.05 M FS, 0.05 M hydrazine. 1.8 mL/min/cm{sup 2} flowrate. (3) Decontamination Wash conditions: Up-flow 1-2 BV of 6.4-8 M HNO{sub 3}, no FS, no hydrazine. (4) Elution conditions: Down-flow 0.17 M HNO{sub 3}, 0.05 M hydrazine, no FS.

  6. First-principles elastic properties of (alpha)-Pu

    SciTech Connect

    Soderlind, P; Klepeis, J

    2009-02-18

    Density-functional electronic-structure calculations have been used to investigate the ambient pressure and low temperature elastic properties of the ground-state {alpha} phase of plutonium metal. The electronic structure and correlation effects are modeled within a fully relativistic antiferromagnetic treatment with a generalized gradient approximation for the electron exchange and correlation functional. The 13 independent elastic constants, for the monoclinic {alpha}-Pu system, are calculated for the observed geometry. A comparison of the results with measured data from recent resonant ultrasound spectroscopy for a cast sample is made.

  7. Automated homogeneous oxalate precipitation of Pu(III)

    SciTech Connect

    Yarbro, S.L.; Schreiber, S.B.; Dunn, S.L.; Mills, C.W.

    1990-01-01

    Homogeneous oxalate precipitation using diethyl oxalate was compared to precipitating Pu(III) oxalate with solid oxalic acid. The diethyl oxalate technique at 75{degree}C is better because it gives 50% less plutonium in the filtrate with a reasonable filtering time. Also, the procedure for the homogeneous precipitation is easier to automate because the liquid diethyl oxalate is simpler to introduce into the precipitator than solid oxalic acid. It also provides flexibility because the hydrolysis rate and therefore the precipitation rate can be controlled by varying the temperature. 5 refs., 3 figs., 3 tabs.

  8. First-principles elastic properties of (alpha)-Pu

    SciTech Connect

    Soderlind, P; Klepeis, J E

    2008-11-04

    Density-functional electronic structure calculations have been used to investigate the ambient pressure and low temperature elastic properties of the ground-state {alpha} phase of plutonium metal. The electronic structure and correlation effects are modeled within a fully relativistic anti-ferromagnetic treatment with a generalized gradient approximation for the electron exchange and correlation functionals. The 13 independent elastic constants, for the monoclinic {alpha}-Pu system, are calculated for the observed geometry. A comparison of the results with measured data from resonant ultrasound spectroscopy for a cast sample is made.

  9. Neutron producing reactions in PuBe neutron sources

    NASA Astrophysics Data System (ADS)

    Bagi, János; Lakosi, László; Nguyen, Cong Tam

    2016-01-01

    There are a plenty of out-of-use plutonium-beryllium neutron sources in Eastern Europe presenting both nuclear safeguards and security issues. Typically, their actual Pu content is not known. In the last couple of years different non-destructive methods were developed for their characterization. For such methods detailed knowledge of the nuclear reactions taking place within the source is necessary. In this paper we investigate the role of the neutron producing reactions, their contribution to the neutron yield and their dependence on the properties of the source.

  10. Design Studies of ``100% Pu'' Mox Lead Test Assembly

    SciTech Connect

    Pavlovichev, A.M.

    2001-01-11

    In this document the results of neutronics studies of <<100%Pu>> MOX LTA design are presented. The parametric studies of infinite MOX-UOX grids, MOX-UOX core fragments and of VVER-1000 core with 3 MOX LTAs are performed. The neutronics parameters of MOX fueled core have been performed for the chosen design MOX LTA using the Russian 3D code BIPR-7A and 2D code PERMAK-A with the constants prepared by the cell spectrum code TVS-M.

  11. Modeling of constituent redistribution in U Pu Zr metallic fuel

    NASA Astrophysics Data System (ADS)

    Kim, Yeon Soo; Hayes, S. L.; Hofman, G. L.; Yacout, A. M.

    2006-12-01

    A computer model was developed to analyze constituent redistribution in U-Pu-Zr metallic nuclear fuels. Diffusion and thermochemical properties were parametrically determined to fit the postirradiation data from a fuel test performed in the Experimental Breeder Reactor II (EBR-II). The computer model was used to estimate redistribution profiles of fuels proposed for the conceptual designs of small modular fast reactors. The model results showed that the level of redistribution of the fuel constituents of the designs was similar to the measured data from EBR-II.

  12. In vivo determination of nitrogen using Pu-Be sources.

    PubMed

    Mernagh, J R; Harrison, J E; McNeill, K G

    1977-09-01

    A mehtod of measuring body nitrogen by neutron capture gamma analysis is described. The neutron flux is provided by four collimated 5 Ci Pu-Be sources, placed to give a bilateral irradiation of the subject. The 10-83 MeV thermal neutron capture gamma rays from 14N are detected by two heavily shielded 5 in X 4 in NaI(Tl) detectors. Results indicate a reproducibility +/-3% (1 SD) for a 10 min irradiation of the chest area, while giving a radiation dose equivalent of 50 mREM.

  13. Neutron Resonance Parameters and Covariance Matrix of 239Pu

    SciTech Connect

    Derrien, Herve; Leal, Luiz C; Larson, Nancy M

    2008-08-01

    In order to obtain the resonance parameters in a single energy range and the corresponding covariance matrix, a reevaluation of 239Pu was performed with the code SAMMY. The most recent experimental data were analyzed or reanalyzed in the energy range thermal to 2.5 keV. The normalization of the fission cross section data was reconsidered by taking into account the most recent measurements of Weston et al. and Wagemans et al. A full resonance parameter covariance matrix was generated. The method used to obtain realistic uncertainties on the average cross section calculated by SAMMY or other processing codes was examined.

  14. Overview of advanced technologies for stabilization of {sup 238}Pu-contaminated waste

    SciTech Connect

    Ramsey, K.B.; Foltyn, E.M.; Heslop, J.M.

    1998-02-01

    This paper presents an overview of potential technologies for stabilization of {sup 238}Pu-contaminated waste. Los Alamos National Laboratory (LANL) has processed {sup 238}PuO{sub 2} fuel into heat sources for space and terrestrial uses for the past several decades. The 88-year half-life of {sup 238}Pu and thermal power of approximately 0.6 watts/gram make this isotope ideal for missions requiring many years of dependable service in inaccessible locations. However, the same characteristic which makes {sup 238}Pu attractive for heat source applications, the high Curie content (17 Ci/gram versus 0.06 Ci/gram for 239{sup Pu}), makes disposal of {sup 238}Pu-contaminated waste difficult. Specifically, the thermal load limit on drums destined for transport to the Waste Isolation Pilot Plant (WIPP), 0.23 gram per drum for combustible waste, is impossible to meet for nearly all {sup 238}Pu-contaminated glovebox waste. Use of advanced waste treatment technologies including Molten Salt Oxidation (MSO) and aqueous chemical separation will eliminate the combustible matrix from {sup 238}Pu-contaminated waste and recover kilogram quantities of {sup 238}PuO{sub 2} from the waste stream. A conceptual design of these advanced waste treatment technologies will be presented.

  15. Activity ratios of 137Cs, 90Sr and 239+240Pu in environmental samples.

    PubMed

    Bossew, P; Lettner, H; Hubmer, A; Erlinger, C; Gastberger, M

    2007-01-01

    Both global and Chernobyl fallout have resulted in environmental contamination with radionuclides such as 137Cs, 90Sr and 239+240Pu. In environmental samples, 137Cs and 239+240Pu can be divided into the contributions of either source, if also the isotopes 134Cs and 238Pu are measurable, based on the known isotopic ratios in global and Chernobyl fallout. No analogous method is available for 90Sr. The activity ratios of Sr to Cs and Pu, respectively, are known for the actual fallout mainly from air filter measurements; but due to the high mobility of Sr in the environment, compared to Cs and Pu, these ratios generally do not hold for the inventory many years after deposition. In this paper we suggest a method to identify the mean contributions of global and Chernobyl fallout to total Sr in soil, sediment and cryoconite samples from Alpine and pre-Alpine regions of Austria, based on a statistical evaluation of Sr/Cs/Pu radionuclide activity ratios. Results are given for Sr:Cs, Sr:Pu and Cs:Pu ratios. Comparison with fallout data shows a strong depletion of Sr against Cs and Pu. PMID:17407799

  16. Overview of advanced technologies for stabilization of 238Pu-contaminated waste

    NASA Astrophysics Data System (ADS)

    Ramsey, Kevin B.; Foltyn, Elizabeth M.; Heslop, J. Mark

    1998-01-01

    This paper presents an overview of potential technologies for stabilization of 238Pu-contaminated waste. Los Alamos National Laboratory (LANL) has processed 238PuO2 fuel into heat sources for space and terrestrial uses for the past several decades. The 88-year half-life of 238Pu and thermal power of approximately 0.6 watts/gram make this isotope ideal for missions requiring many years of dependable service in inaccessible locations. However, the same characteristic which makes 238Pu attractive for heat source applications, the high Curie content (17 Ci/gram versus 0.06 Ci/gram for 239Pu), makes disposal of 238Pu-contaminated waste difficult. Specifically, the thermal load limit on drums destined for transport to the Waste Isolation Pilot Plant (WIPP), 0.23 gram per drum for combustible waste, is impossible to meet for nearly all 238Pu-contaminated glovebox waste. Use of advanced waste treatment technologies including Molten Salt Oxidation (MSO) and aqueous chemical separation will eliminate the combustible matrix from 238Pu-contaminated waste and recover kilogram quantities of 238PuO2 from the waste stream. A conceptual design of these advanced waste treatment technologies will be presented.

  17. Experimental geochemistry of Pu and Sm and the thermodynamics of trace element partitioning

    NASA Technical Reports Server (NTRS)

    Jones, John H.; Burnett, Donald S.

    1987-01-01

    An experimental study of the partitioning of Pu and Sm between diopside/liquid and whitlockite/liquid supports the hypothesis that Pu behaves as a light rare earth element during igneous processes in reducing environments. D-Pu/D-Sm is found to be about 2 for both diopsidic pyroxene and whitlockite, and the amount of fractionation would be decreased further if Pu were compared to Ce or Nd. Data indicate that temperature, rather than melt composition, is the most important control on elemental partitioning, and that P2O5 in aluminosilicate melts serves as a complexing agent for the actinides and lanthanides.

  18. A Method for Continuous (239)Pu Determinations in Arctic and Antarctic Ice Cores.

    PubMed

    Arienzo, M M; McConnell, J R; Chellman, N; Criscitiello, A S; Curran, M; Fritzsche, D; Kipfstuhl, S; Mulvaney, R; Nolan, M; Opel, T; Sigl, M; Steffensen, J P

    2016-07-01

    Atmospheric nuclear weapons testing (NWT) resulted in the injection of plutonium (Pu) into the atmosphere and subsequent global deposition. We present a new method for continuous semiquantitative measurement of (239)Pu in ice cores, which was used to develop annual records of fallout from NWT in ten ice cores from Greenland and Antarctica. The (239)Pu was measured directly using an inductively coupled plasma-sector field mass spectrometer, thereby reducing analysis time and increasing depth-resolution with respect to previous methods. To validate this method, we compared our one year averaged results to published (239)Pu records and other records of NWT. The (239)Pu profiles from the Arctic ice cores reflected global trends in NWT and were in agreement with discrete Pu profiles from lower latitude ice cores. The (239)Pu measurements in the Antarctic ice cores tracked low latitude NWT, consistent with previously published discrete records from Antarctica. Advantages of the continuous (239)Pu measurement method are (1) reduced sample preparation and analysis time; (2) no requirement for additional ice samples for NWT fallout determinations; (3) measurements are exactly coregistered with all other chemical, elemental, isotopic, and gas measurements from the continuous analytical system; and (4) the long half-life means the (239)Pu record is stable through time. PMID:27244483

  19. Fuel-Cladding Interaction Between U-Pu-Zr Fuel and Fe

    NASA Astrophysics Data System (ADS)

    Aitkaliyeva, Assel; Madden, James W.; Miller, Brandon D.; Papesch, Cynthia A.; Cole, James I.

    2015-12-01

    This work investigates fuel-cladding chemical interaction (FCCI) between U-25Pu-14Zr (in wt pct) fuel and pure Fe at elevated temperatures, understanding of which is critical for evaluation of the fuel performance. Phases and microstructure formed in the quaternary uranium-plutonium-zirconium-iron (U-Pu-Zr-Fe) system were characterized using the transmission electron microscopy technique. Phases formed within the FCCI layer were identified using selective area electron diffraction (SAED) analysis as Fe2U (Fd- m), Fe2Zr (Fd-3m), α-U (Cmcm), Fe2Pu (Fd-3m), β-Pu (C12/m1), and β-Zr (Im-3m).

  20. Pharmacologic efficacy of PU.1 inhibition by heterocyclic dications: a mechanistic analysis

    PubMed Central

    Stephens, Dominique C.; Kim, Hye Mi; Kumar, Arvind; Farahat, Abdelbasset A.; Boykin, David W.; K. Poon, Gregory M.

    2016-01-01

    Heterocyclic dications are receiving increasing attention as targeted inhibitors of transcription factors. While many dications act as purely competitive inhibitors, some fail to displace protein efficiently at drug concentrations expected to saturate their DNA target. To achieve a mechanistic understanding of these non-competitive effects, we used a combination of dications, which are intrinsically fluorescent and spectrally-separated fluorescently labeled DNA to dissect complex interactions in multi-component drug/DNA/protein systems. Specifically, we interrogated site-specific binding by the transcription factor PU.1 and its perturbation by DB270, a furan-bisbenzimidazole-diamidine that strongly targets PU.1 binding sites yet poorly inhibits PU.1/DNA complexes. By titrating DB270 and/or cyanine-labeled DNA with protein or unlabeled DNA, and following the changes in their fluorescence polarization, we found direct evidence that DB270 bound protein independently of their mutual affinities for sequence-specific DNA. Each of the three species competed for the other two, and this interplay of mutually dependent equilibria abrogated DB270's inhibitory activity, which was substantively restored under conditions that attenuated DB270/PU.1 binding. PU.1 binding was consistent with DB270's poor inhibitory efficacy of PU.1 in vivo, while its isosteric selenophene analog (DB1976), which did not bind PU.1 and strongly inhibited the PU.1/DNA complex in vitro, fully antagonized PU.1-dependent transactivation in vivo. PMID:27079976

  1. Pharmacologic efficacy of PU.1 inhibition by heterocyclic dications: a mechanistic analysis.

    PubMed

    Stephens, Dominique C; Kim, Hye Mi; Kumar, Arvind; Farahat, Abdelbasset A; Boykin, David W; K Poon, Gregory M

    2016-05-19

    Heterocyclic dications are receiving increasing attention as targeted inhibitors of transcription factors. While many dications act as purely competitive inhibitors, some fail to displace protein efficiently at drug concentrations expected to saturate their DNA target. To achieve a mechanistic understanding of these non-competitive effects, we used a combination of dications, which are intrinsically fluorescent and spectrally-separated fluorescently labeled DNA to dissect complex interactions in multi-component drug/DNA/protein systems. Specifically, we interrogated site-specific binding by the transcription factor PU.1 and its perturbation by DB270, a furan-bisbenzimidazole-diamidine that strongly targets PU.1 binding sites yet poorly inhibits PU.1/DNA complexes. By titrating DB270 and/or cyanine-labeled DNA with protein or unlabeled DNA, and following the changes in their fluorescence polarization, we found direct evidence that DB270 bound protein independently of their mutual affinities for sequence-specific DNA. Each of the three species competed for the other two, and this interplay of mutually dependent equilibria abrogated DB270's inhibitory activity, which was substantively restored under conditions that attenuated DB270/PU.1 binding. PU.1 binding was consistent with DB270's poor inhibitory efficacy of PU.1 in vivo, while its isosteric selenophene analog (DB1976), which did not bind PU.1 and strongly inhibited the PU.1/DNA complex in vitro, fully antagonized PU.1-dependent transactivation in vivo.

  2. A Method for Continuous (239)Pu Determinations in Arctic and Antarctic Ice Cores.

    PubMed

    Arienzo, M M; McConnell, J R; Chellman, N; Criscitiello, A S; Curran, M; Fritzsche, D; Kipfstuhl, S; Mulvaney, R; Nolan, M; Opel, T; Sigl, M; Steffensen, J P

    2016-07-01

    Atmospheric nuclear weapons testing (NWT) resulted in the injection of plutonium (Pu) into the atmosphere and subsequent global deposition. We present a new method for continuous semiquantitative measurement of (239)Pu in ice cores, which was used to develop annual records of fallout from NWT in ten ice cores from Greenland and Antarctica. The (239)Pu was measured directly using an inductively coupled plasma-sector field mass spectrometer, thereby reducing analysis time and increasing depth-resolution with respect to previous methods. To validate this method, we compared our one year averaged results to published (239)Pu records and other records of NWT. The (239)Pu profiles from the Arctic ice cores reflected global trends in NWT and were in agreement with discrete Pu profiles from lower latitude ice cores. The (239)Pu measurements in the Antarctic ice cores tracked low latitude NWT, consistent with previously published discrete records from Antarctica. Advantages of the continuous (239)Pu measurement method are (1) reduced sample preparation and analysis time; (2) no requirement for additional ice samples for NWT fallout determinations; (3) measurements are exactly coregistered with all other chemical, elemental, isotopic, and gas measurements from the continuous analytical system; and (4) the long half-life means the (239)Pu record is stable through time.

  3. E2A Antagonizes PU.1 Activity through Inhibition of DNA Binding.

    PubMed

    Rogers, Jason H; Owens, Kristin S; Kurkewich, Jeffrey; Klopfenstein, Nathan; Iyer, Sangeeta R; Simon, M Celeste; Dahl, Richard

    2016-01-01

    Antagonistic interactions between transcription factors contribute to cell fate decisions made by multipotent hematopoietic progenitor cells. Concentration of the transcription factor PU.1 affects myeloid/lymphoid development with high levels of PU.1 directing myeloid cell fate acquisition at the expense of B cell differentiation. High levels of PU.1 may be required for myelopoiesis in order to overcome inhibition of its activity by transcription factors that promote B cell development. The B cell transcription factors, E2A and EBF, are necessary for commitment of multipotential progenitors and lymphoid primed multipotential progenitors to lymphocytes. In this report we hypothesized that factors required for early B cell commitment would bind to PU.1 and antagonize its ability to induce myeloid differentiation. We investigated whether E2A and/or EBF associate with PU.1. We observed that the E2A component, E47, but not EBF, directly binds to PU.1. Additionally E47 represses PU.1-dependent transactivation of the MCSFR promoter through antagonizing PU.1's ability to bind to DNA. Exogenous E47 expression in hematopoietic cells inhibits myeloid differentiation. Our data suggest that E2A antagonism of PU.1 activity contributes to its ability to commit multipotential hematopoietic progenitors to the lymphoid lineages.

  4. Reaction of plutonium with water kinetic and equilibrium behavior of binary and ternary phases in the Pu + O + H system

    SciTech Connect

    Haschke, J.M.; Hodges, A.E. III; Bixby, G.E.; Lucas, R.L.

    1983-02-03

    The kinetic and equilibrium behavior of the Pu + O + H system has been studied by measuring the production of hydrogen gas formed by a sequence of hydrolysis reactions. The kinetic dependence of the Pu + H/sub 2/O reaction on salt concentration and temperature has been defined. The metal is quantitatively converted to a fine black powder which has been identified as plutonium monoxide monohydride, PuOH. Other hydrolysis products formed in aqueous media include a second oxide hydride, Pu/sub 7/O/sub 9/H/sub 3/, and the oxides Pu/sub 2/O/sub 3/, Pu/sub 7/O/sub 12/, Pu/sub 9/O/sub 16/, Pu/sub 10/O/sub 18/, Pu/sub 12/O/sub 22/, and PuO/sub 2/. Thermal decomposition products of PuOH include Pu/sub 2/O/sub 2/H and PuO. A tentative phase diagram for Pu + O + H is presented and structural relationships of the oxide hydrides and oxides are discussed. 10 figures, 5 tables.

  5. Genome-scale definition of the transcriptional programme associated with compromised PU.1 activity in acute myeloid leukaemia.

    PubMed

    Sive, J I; Basilico, S; Hannah, R; Kinston, S J; Calero-Nieto, F J; Göttgens, B

    2016-01-01

    Transcriptional dysregulation is associated with haematological malignancy. Although mutations of the key haematopoietic transcription factor PU.1 are rare in human acute myeloid leukaemia (AML), they are common in murine models of radiation-induced AML, and PU.1 downregulation and/or dysfunction has been described in human AML patients carrying the fusion oncogenes RUNX1-ETO and PML-RARA. To study the transcriptional programmes associated with compromised PU.1 activity, we adapted a Pu.1-mutated murine AML cell line with an inducible wild-type PU.1. PU.1 induction caused transition from leukaemia phenotype to monocytic differentiation. Global binding maps for PU.1, CEBPA and the histone mark H3K27Ac with and without PU.1 induction showed that mutant PU.1 retains DNA-binding ability, but the induction of wild-type protein dramatically increases both the number and the height of PU.1-binding peaks. Correlating chromatin immunoprecipitation (ChIP) Seq with gene expression data, we found that PU.1 recruitment coupled with increased histone acetylation induces gene expression and activates a monocyte/macrophage transcriptional programme. PU.1 induction also caused the reorganisation of a subgroup of CEBPA binding peaks. Finally, we show that the PU.1 target gene set defined in our model allows the stratification of primary human AML samples, shedding light on both known and novel AML subtypes that may be driven by PU.1 dysfunction.

  6. Transport of (137)Cs, (241)Am and Pu isotopes in the Curonian Lagoon and the Baltic Sea.

    PubMed

    Lujanienė, G; Remeikaitė-Nikienė, N; Garnaga, G; Jokšas, K; Šilobritienė, B; Stankevičius, A; Šemčuk, S; Kulakauskaitė, I

    2014-01-01

    Activities of (137)Cs, (241)Am and (239,240)Pu were analyzed with special emphasis on better understanding of radionuclide transport from land via the Neman River estuaries to the Baltic Sea and behavior in the marine environment. Although activity concentrations of (137)Cs in water samples collected the Baltic Sea were almost 100 times higher as compared to the Curonian Lagoon, its activities in the bottom sediments were found to be comparable. Activity (238)Pu/(239,240)Pu and atom (240)Pu/(239)Pu ratios indicated a different contribution of the Chernobyl-originated Pu to the suspended particulate matter (SPM) and bottom sediments. The largest amount of the Chernobyl-derived Pu was found in the smallest suspended matter particles of 0.2-1 μm in size collected in the Klaipeda Strait in 2011-2012. The decrease of characteristic activity (238)Pu/(239,240)Pu and atom (240)Pu/(239)Pu ratios towards the global fallout ones in surface soil and the corresponding increase of plutonium (Pu) ratios in the suspended particulate matter and bottom sediments have indicated that the Chernobyl-derived Pu, primarily deposited on the soil surface, was washed out and transported to the Baltic Sea. Behavior of (241)Am was found to be similar to that of Pu isotopes.

  7. Free energy of formation of Cs{sub 3}PuCl{sub 6} and CsPu{sub 2}Cl{sub 7}

    SciTech Connect

    Willamson, M.A.; Kleinschmidt, P.D.

    1992-09-01

    The free energy, enthalpy and entropy of formation of the compounds Cs{sub 3}PuCl{sub 6} and CsPu{sub 2}Cl{sub 7} have been determined by measuring the sublimation pressures for the reactions: CsCl(s) = CsCl(g), 2/5 Cs{sub 3}PuCl{sub 6}(s) = 1/5 CsPu{sub 2}Cl{sub 7}(s) + CsCl(g), and CsPu{sub 2}Cl{sub 7}(s) = 2 PuCl{sub 3}(s) + CsCl(g). The pressures are measured using Knudsen effusion mass spectrometry over the temperature range 600 to 850 K. For the formation of Cs{sub 3}PuCl{sub 6} from CsCl and PuCl{sub 3}, {Delta}G{sub 298}{sup 0} = {minus}77.3 +/{minus} 8.5 kJ/mole, {Delta}H{sub 298}{sup 0} = {minus}82.1 +/{minus} 7.8 kJ mole, and {Delta}S{sup 298}{sup 0} = {minus}16.2 +/{minus} 10.9 J/K mole. For CsPu{sub 2}Cl{sub 7}, {Delta}G{sub 298}{sup 0} = {minus}39.4 +/{minus} 3.5 kJ/mole, {Delta}H{sub 298}{sup 0} = {minus}40.8 +/{minus} 3.2 kJ/mole, and {Delta}S{sub 298}{sup 0} = {minus}4.6 +/{minus} 4.2 J/K mole.

  8. Free energy of formation of Cs sub 3 PuCl sub 6 and CsPu sub 2 Cl sub 7

    SciTech Connect

    Willamson, M.A.; Kleinschmidt, P.D.

    1992-01-01

    The free energy, enthalpy and entropy of formation of the compounds Cs{sub 3}PuCl{sub 6} and CsPu{sub 2}Cl{sub 7} have been determined by measuring the sublimation pressures for the reactions: CsCl(s) = CsCl(g), 2/5 Cs{sub 3}PuCl{sub 6}(s) = 1/5 CsPu{sub 2}Cl{sub 7}(s) + CsCl(g), and CsPu{sub 2}Cl{sub 7}(s) = 2 PuCl{sub 3}(s) + CsCl(g). The pressures are measured using Knudsen effusion mass spectrometry over the temperature range 600 to 850 K. For the formation of Cs{sub 3}PuCl{sub 6} from CsCl and PuCl{sub 3}, {Delta}G{sub 298}{sup 0} = {minus}77.3 +/{minus} 8.5 kJ/mole, {Delta}H{sub 298}{sup 0} = {minus}82.1 +/{minus} 7.8 kJ mole, and {Delta}S{sup 298}{sup 0} = {minus}16.2 +/{minus} 10.9 J/K mole. For CsPu{sub 2}Cl{sub 7}, {Delta}G{sub 298}{sup 0} = {minus}39.4 +/{minus} 3.5 kJ/mole, {Delta}H{sub 298}{sup 0} = {minus}40.8 +/{minus} 3.2 kJ/mole, and {Delta}S{sub 298}{sup 0} = {minus}4.6 +/{minus} 4.2 J/K mole.

  9. Decreased solubilization of Pu(IV) polymers by humic acids under anoxic conditions

    NASA Astrophysics Data System (ADS)

    Xie, Jinchuan; Lin, Jianfeng; Liang, Wei; Li, Mei; Zhou, Xiaohua

    2016-11-01

    Pu(IV) polymer has a very low solubility (log[Pu(IV)aq]total = -10.4 at pH 7.2 and I = 0). However, some aspects of their environmental fate remain unclear. Humic acids are able to complex with Pu4+ ions and their dissolved species (<10 kD) in the groundwater (neutral to alkaline pH) may cause solubilization of the polymers. Also, humic acids have the native reducing capacity and potentially reduce the polymeric Pu(IV) to Pu(III)aq (log[Pu(III)aq]total = -5.3 at pH 7.2 and I = 0). Solubilization and reduction of the polymers can enhance their mobility in subsurface environments. Nevertheless, humic acids readily coat the surfaces of metal oxides via electrostatic interaction and ligand exchange mechanisms. The humic coatings are expected to prevent both solubilization and reduction of the polymers. Experiments were conducted under anoxic and slightly alkaline (pH 7.2) conditions in order to study whether humic acids have effects on stability of the polymers. The results show that the polymeric Pu(IV) was almost completely transformed into aqueous Pu(IV) in the presence of EDTA ligands. In contrast, the dissolved humic acids did not solubilize the polymers but in fact decreased their solubility by one order of magnitude. The humic coatings were responsible for the decreased solubilization. Such coatings limited the contact between the polymers and EDTA ligands, especially at the relatively high concentrations of humic acids (>0.57 mg/L). Solubilization of the humic-coated polymers was thus inhibited to a significant extent although EDTA, having the great complexation ability, was present in the humic solutions. Reduction of Pu(IV) polymers by the humic acids was also not observed in the absence of EDTA. In the presence of EDTA, the polymers were partially reduced to Pu(III)aq by the humic acids of 0.57 mg/L and the percentage of Pu(III)aq accounted for 51.7% of the total aqueous Pu. This demonstrates that the humic acids were able to reduce the aqueous Pu

  10. Calibration of the ERL cavity FPC and PU couplers

    SciTech Connect

    Hahn, H.; Johnson, E.; Kayran, D.

    2010-04-05

    The performance parameters of a superconducting cavity, notably accelerating field and quality factor, are first obtained in a cryogenic vertical test Dewar, and again after the final assembly in its cryostat. The tests involve Network Analyzer (NA) measurements in which the cavity is excited through an input coupler and the properties are obtained from the reflected signal at the input and the transmitted signal from the output coupler. The interpretation of the scattering coefficients in terms of field strength requires the knowledge of the Fundamental Power Coupler (FPC) and Pick-Up (PU) coupler strength, as expressed by their 'external' and Q{sub FPC} Q{sub PU}. The coupler strength is independent of the field level or cavity losses and thus can be determined at low levels with the scattering coefficients S{sub 11} and S{sub 21}, assuming standard 50 {Omega} terminations in the network analyzer. Also needed is the intrinsic cavity parameter, R{sub a} /Q{sub 0} {triple_bond} {l_brace}R/Q{r_brace}, a quantity independent of field or losses which must be obtained from simulation programs, such as the Microwave Studio.

  11. Thermal Analysis of ZPPR High Pu Content Stored Fuel

    DOE PAGES

    Solbrig, Charles W.; Pope, Chad L.; Andrus, Jason P.

    2014-01-01

    The Zero Power Physics Reactor (ZPPR) operated from April 18, 1969, until 1990. ZPPR operated at low power for testing nuclear reactor designs. This paper examines the temperature of Pu content ZPPR fuel while it is in storage. Heat is generated in the fuel due to Pu and Am decay and is a concern for possible cladding damage. Damage to the cladding could lead to fuel hydriding and oxidizing. A series of computer simulations were made to determine the range of temperatures potentially occuring in the ZPPR fuel. The maximum calculated fuel temperature is 292°C (558°F). Conservative assumptions in themore » model intentionally overestimate temperatures. The stored fuel temperatures are dependent on the distribution of fuel in the surrounding storage compartments, the heat generation rate of the fuel, and the orientation of fuel. Direct fuel temperatures could not be measured but storage bin doors, storage sleeve doors, and storage canister temperatures were measured. Comparison of these three temperatures to the calculations indicates that the temperatures calculated with conservative assumptions are, as expected, higher than the actual temperatures. The maximum calculated fuel temperature with the most conservative assumptions is significantly below the fuel failure criterion of 600°C (1,112°F).« less

  12. Radiation damage effects in candidate titanates for Pu disposition: Zirconolite

    NASA Astrophysics Data System (ADS)

    Strachan, D. M.; Scheele, R. D.; Buck, E. C.; Kozelisky, A. E.; Sell, R. L.; Elovich, R. J.; Buchmiller, W. C.

    2008-01-01

    Results from studies of radiation-induced damage from the alpha decay of 238Pu on the density and crystal structure of a nominally phase-pure zirconolite and two other zirconolite-bearing ceramics are discussed. Macro and micro swelling were found to be temperature independent, whereas the density determined with He gas pycnometry was temperature dependent. Approximately 2.6 × 10 18 α/g were needed to render the specimens X-ray amorphous- more to saturate the swelling. Unlike pyrochlore-based ceramics, we did not observe any phase changes associated with storage temperature and damage ingrowth. The forward dissolution rate at a pH value of 2 for material containing essentially all zirconolite is 1.7(4) × 10 -3 g/(m 2 d) with very little pH dependence and no dependence on the amount of radiation-induced damage. Even after the radiation-induced swelling saturated, the specimens remained physically intact with no evidence for microcracking. Thus, the material remains physically a viable material for the disposition of surplus weapons-grade Pu.

  13. U, Np, Pu and Am Prompt Fission Neutron Spectra

    SciTech Connect

    Maslov, Vladimir M.

    2008-05-12

    Prompt fission neutron spectra (PFNS) components due to soft and hard pre-fission neutrons are revealed in PFNS data of {sup 232}Th(n,F), {sup 238}U(n,F), {sup 235}U(n,F) and {sup 239}Pu(n,F) reactions for E{sub n}{<=}20 MeV. Average energies of these PFNS are systematically shifted to higher values, so that Th fission fragments look least heated, while those of Pu--most heated. The average energy is correlated with the emissive fission chances contributions to the observed fission cross sections. The predicted contribution of (n,xnf) neutrons is most pronounced in case of {sup 232}Th(n,F) reaction. The approach, based on the consistent description of {sup 237}Np(n,F), {sup 237}Np(n,2n){sup 236s}Np and {sup 241}Am(n,F), {sup 241}Am(n,2n) is used to predict the PFNS of the {sup 237}Np(n,F) and {sup 241}Am(n,F) reactions.

  14. Report on the 3'rd scientific meeting of the "Verein zur Förderung des Wissenschaftlichen Nachwuchses in der Neurologie" (NEUROWIND e.V.) held in Motzen, Germany, Nov. 4'th - Nov. 6'th, 2011

    PubMed Central

    2012-01-01

    From November 4th- 6th 2011, the 3rd NEUROWIND e.V. meeting was held in Motzen, Brandenburg, Germany. Like in the previous years, the meeting provided an excellent platform for scientific exchange and the presentation of innovative projects for young colleagues in the fields of neurovascular research, neuroinflammation and neurodegeneration. As kick-off to the scientific sessions, Reinhard Hohlfeld, Head of the Institute for Clinical Neuroimmunology in Munich, gave an illustrious overview on the many fascinations of neuroimmunologic research. A particular highlight on the second day of the meeting was the award of the 1'st NEUROWIND e.V. prize for young academics in the field of experimental neurology. This award is posted for young colleagues under the age of 35 with a significant achievement in the field of neurovascular research, neuroinflammation or neurodegeneration and comprises an amount of 20.000 Euro, founded by Merck Serono GmbH, Darmstadt. Germany. The first prize was awarded to Ivana Nikic from Martin Kerschensteiner's group in Munich for her brilliant work on a reversible form of axon damage in experimental autoimmune encephalomyelitis and multiple sclerosis, published in Nature Medicine in 2011. This first prize award ceremony was a great incentive for the next call for proposals now upcoming in 2012. PMID:22360825

  15. Chronology of Pu isotopes and 236U in an Arctic ice core.

    PubMed

    Wendel, C C; Oughton, D H; Lind, O C; Skipperud, L; Fifield, L K; Isaksson, E; Tims, S G; Salbu, B

    2013-09-01

    In the present work, state of the art isotopic fingerprinting techniques are applied to an Arctic ice core in order to quantify deposition of U and Pu, and to identify possible tropospheric transport of debris from former Soviet Union test sites Semipalatinsk (Central Asia) and Novaya Zemlya (Arctic Ocean). An ice core chronology of (236)U, (239)Pu, and (240)Pu concentrations, and atom ratios, measured by accelerator mass spectrometry in a 28.6m deep ice core from the Austfonna glacier at Nordaustlandet, Svalbard is presented. The ice core chronology corresponds to the period 1949 to 1999. The main sources of Pu and (236)U contamination in the Arctic were the atmospheric nuclear detonations in the period 1945 to 1980, as global fallout, and tropospheric fallout from the former Soviet Union test sites Novaya Zemlya and Semipalatinsk. Activity concentrations of (239+240)Pu ranged from 0.008 to 0.254 mBq cm(-2) and (236)U from 0.0039 to 0.053 μBq cm(-2). Concentrations varied in concordance with (137)Cs concentrations in the same ice core. In contrast to previous published results, the concentrations of Pu and (236)U were found to be higher at depths corresponding to the pre-moratorium period (1949 to 1959) than to the post-moratorium period (1961 and 1962). The (240)Pu/(239)Pu ratio ranged from 0.15 to 0.19, and (236)U/(239)Pu ranged from 0.18 to 1.4. The Pu atom ratios ranged within the limits of global fallout in the most intensive period of nuclear atmospheric testing (1952 to 1962). To the best knowledge of the authors the present work is the first publication on biogeochemical cycles with respect to (236)U concentrations and (236)U/(239)Pu atom ratios in the Arctic and in ice cores.

  16. Plutonium concentration and (240)Pu/(239)Pu atom ratio in biota collected from Amchitka Island, Alaska: recent measurements using ICP-SFMS.

    PubMed

    Bu, Kaixuan; Cizdziel, James V; Dasher, Douglas

    2013-10-01

    Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for (239)Pu and (240)Pu concentration and (240)Pu/(239)Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and (240)Pu/(239)Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The ((239)+)(240)Pu levels (mBq kg(-1), dry weight) ranged from 3.79 to 57.1 for lichen, 167-700 for kelp, 27.9-148 for horse mussel, and 560-573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The (240)Pu/(239)Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p < 0.001); lichen and moss averaged 0.184 ± 0.007, similar to the integrated global fallout ratio, whereas kelp and mussel (soft tissue) averaged 0.226 ± 0.003. These observations provide supporting evidence that a large input of isotopically heavier Pu occurred into the North Pacific Ocean, likely from the Marshall Island high yield nuclear tests, but other potential sources, such as the Kamchatka Peninsula Rybachiy Naval Base and

  17. Plutonium concentration and (240)Pu/(239)Pu atom ratio in biota collected from Amchitka Island, Alaska: recent measurements using ICP-SFMS.

    PubMed

    Bu, Kaixuan; Cizdziel, James V; Dasher, Douglas

    2013-10-01

    Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for (239)Pu and (240)Pu concentration and (240)Pu/(239)Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and (240)Pu/(239)Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The ((239)+)(240)Pu levels (mBq kg(-1), dry weight) ranged from 3.79 to 57.1 for lichen, 167-700 for kelp, 27.9-148 for horse mussel, and 560-573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The (240)Pu/(239)Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p < 0.001); lichen and moss averaged 0.184 ± 0.007, similar to the integrated global fallout ratio, whereas kelp and mussel (soft tissue) averaged 0.226 ± 0.003. These observations provide supporting evidence that a large input of isotopically heavier Pu occurred into the North Pacific Ocean, likely from the Marshall Island high yield nuclear tests, but other potential sources, such as the Kamchatka Peninsula Rybachiy Naval Base and

  18. ZPR-6 assembly 7 high {sup 240}Pu core experiments : a fast reactor core with mixed (Pu,U)-oxide fuel and a centeral high{sup 240}Pu zone.

    SciTech Connect

    Lell, R. M.; Morman, J. A.; Schaefer, R.W.; McKnight, R.D.; Nuclear Engineering Division

    2009-02-23

    ZPR-6 Assembly 7 (ZPR-6/7) encompasses a series of experiments performed at the ZPR-6 facility at Argonne National Laboratory in 1970 and 1971 as part of the Demonstration Reactor Benchmark Program (Reference 1). Assembly 7 simulated a large sodium-cooled LMFBR with mixed oxide fuel, depleted uranium radial and axial blankets, and a core H/D near unity. ZPR-6/7 was designed to test fast reactor physics data and methods, so configurations in the Assembly 7 program were as simple as possible in terms of geometry and composition. ZPR-6/7 had a very uniform core assembled from small plates of depleted uranium, sodium, iron oxide, U{sub 3}O{sub 8} and Pu-U-Mo alloy loaded into stainless steel drawers. The steel drawers were placed in square stainless steel tubes in the two halves of a split table machine. ZPR-6/7 had a simple, symmetric core unit cell whose neutronic characteristics were dominated by plutonium and {sup 238}U. The core was surrounded by thick radial and axial regions of depleted uranium to simulate radial and axial blankets and to isolate the core from the surrounding room. The ZPR-6/7 program encompassed 139 separate core loadings which include the initial approach to critical and all subsequent core loading changes required to perform specific experiments and measurements. In this context a loading refers to a particular configuration of fueled drawers, radial blanket drawers and experimental equipment (if present) in the matrix of steel tubes. Two principal core configurations were established. The uniform core (Loadings 1-84) had a relatively uniform core composition. The high {sup 240}Pu core (Loadings 85-139) was a variant on the uniform core. The plutonium in the Pu-U-Mo fuel plates in the uniform core contains 11% {sup 240}Pu. In the high {sup 240}Pu core, all Pu-U-Mo plates in the inner core region (central 61 matrix locations per half of the split table machine) were replaced by Pu-U-Mo plates containing 27% {sup 240}Pu in the plutonium

  19. Determination of /sup 239,240/Pu in bottom sediments of the Baltic Sea

    SciTech Connect

    Kuznetsov, Yu.V.; Legin, V.K.; Pospelov, Yu.N.; Simonyak, Z.N.

    1988-11-01

    We present a technique for determining the /sup 239,240/Pu content, using /sup 236/Pu as the monitor of chemical yield, in samples of soils and bottom sediments - objects of the external environment. Plutonium is extracted from the matrix material by leaching with a mixture of concentrated acids HCl-HNO/sub 3/, after which it is separated by ion-exchange methods. After electrodeposition onto stainless steel discs the activity of the nuclides of plutonium is measured by the method of alpha-spectrometry. The average chemical yields during the analysis of the samples was 40-60%, the relative standard deviation was 10%, and the lower limit of detectability was 0.3 Bq. We present results of the determination of the /sup 239,240/Pu content in surface samples of bottom sediments from the Gulf of Finland and that past of the Baltic Sea which adjoins the territory of the USSR. It is found that the unit activity of /sup 239,240/Pu in the bottom sediments varies within the limits of 0.4-1.2 Bq/kg and lies at the global level. Global genesis of /sup 239,240/Pu in the bottom sediments of the Gulf of Finland and the open parts of the Baltic Sea is also confirmed by the values which are found for the ratios /sup 238/Pu//sup 239,240/Pu and /sup 239,240/Pu//sup 137/Cs.

  20. Pu isotopes in soils collected downwind from Lop Nor: regional fallout vs. global fallout

    NASA Astrophysics Data System (ADS)

    Bu, Wenting; Ni, Youyi; Guo, Qiuju; Zheng, Jian; Uchida, Shigeo

    2015-07-01

    For the first time, soil core samples from the Jiuquan region have been analyzed for Pu isotopes for radioactive source identification and radiological assessment. The Jiuquan region is in downwind from the Lop Nor Chinese nuclear test (CNT) site. The high Pu inventories (13 to 546 Bq/m2) in most of the sampling locations revealed that this region was heterogeneously contaminated by the regional fallout Pu from the CNTs. The contributions of the CNTs to the total Pu in soils were estimated to be more than 40% in most cases. The 240Pu/239Pu atom ratios in the soils ranged from 0.059 to 0.186 with an inventory-weighted average of 0.158, slightly lower than that of global fallout. This atom ratio could be considered as a mixed fingerprint of Pu from the CNTs. In addition, Pu in soils of Jiuquan region had a faster downward migration rate compared with other investigated places in China.

  1. Pu isotopes in soils collected downwind from Lop Nor: regional fallout vs. global fallout

    PubMed Central

    Bu, Wenting; Ni, Youyi; Guo, Qiuju; Zheng, Jian; Uchida, Shigeo

    2015-01-01

    For the first time, soil core samples from the Jiuquan region have been analyzed for Pu isotopes for radioactive source identification and radiological assessment. The Jiuquan region is in downwind from the Lop Nor Chinese nuclear test (CNT) site. The high Pu inventories (13 to 546 Bq/m2) in most of the sampling locations revealed that this region was heterogeneously contaminated by the regional fallout Pu from the CNTs. The contributions of the CNTs to the total Pu in soils were estimated to be more than 40% in most cases. The 240Pu/239Pu atom ratios in the soils ranged from 0.059 to 0.186 with an inventory-weighted average of 0.158, slightly lower than that of global fallout. This atom ratio could be considered as a mixed fingerprint of Pu from the CNTs. In addition, Pu in soils of Jiuquan region had a faster downward migration rate compared with other investigated places in China. PMID:26184740

  2. PU.1 cooperates with IRF4 and IRF8 to suppress pre-B-cell leukemia.

    PubMed

    Pang, S H M; Minnich, M; Gangatirkar, P; Zheng, Z; Ebert, A; Song, G; Dickins, R A; Corcoran, L M; Mullighan, C G; Busslinger, M; Huntington, N D; Nutt, S L; Carotta, S

    2016-06-01

    The Ets family transcription factor PU.1 and the interferon regulatory factor (IRF)4 and IRF8 regulate gene expression by binding to composite DNA sequences known as Ets/interferon consensus elements. Although all three factors are expressed from the onset of B-cell development, single deficiency of these factors in B-cell progenitors only mildly impacts on bone marrow B lymphopoiesis. Here we tested whether PU.1 cooperates with IRF factors in regulating early B-cell development. Lack of PU.1 and IRF4 resulted in a partial block in development the pre-B-cell stage. The combined deletion of PU.1 and IRF8 reduced recirculating B-cell numbers. Strikingly, all PU.1/IRF4 and ~50% of PU.1/IRF8 double deficient mice developed pre-B-cell acute lymphoblastic leukemia (B-ALL) associated with reduced expression of the established B-lineage tumor suppressor genes, Ikaros and Spi-B. These genes are directly regulated by PU.1/IRF4/IRF8, and restoration of Ikaros or Spi-B expression inhibited leukemic cell growth. In summary, we demonstrate that PU.1, IRF4 and IRF8 cooperate to regulate early B-cell development and to prevent pre-B-ALL formation.

  3. Pu isotopes in soils collected downwind from Lop Nor: regional fallout vs. global fallout.

    PubMed

    Bu, Wenting; Ni, Youyi; Guo, Qiuju; Zheng, Jian; Uchida, Shigeo

    2015-07-17

    For the first time, soil core samples from the Jiuquan region have been analyzed for Pu isotopes for radioactive source identification and radiological assessment. The Jiuquan region is in downwind from the Lop Nor Chinese nuclear test (CNT) site. The high Pu inventories (13 to 546 Bq/m(2)) in most of the sampling locations revealed that this region was heterogeneously contaminated by the regional fallout Pu from the CNTs. The contributions of the CNTs to the total Pu in soils were estimated to be more than 40% in most cases. The (240)Pu/(239)Pu atom ratios in the soils ranged from 0.059 to 0.186 with an inventory-weighted average of 0.158, slightly lower than that of global fallout. This atom ratio could be considered as a mixed fingerprint of Pu from the CNTs. In addition, Pu in soils of Jiuquan region had a faster downward migration rate compared with other investigated places in China.

  4. Characterization of pu-erh tea using chemical and metabolic profiling approaches.

    PubMed

    Xie, Guoxiang; Ye, Mao; Wang, Yungang; Ni, Yan; Su, Mingming; Huang, Hua; Qiu, Mingfeng; Zhao, Aihua; Zheng, Xiaojiao; Chen, Tianlu; Jia, Wei

    2009-04-22

    In this study, the chemical constituents of pu-erh tea, black tea, and green tea, as well as those of pu-erh tea products of different ages, were analyzed and compared using a chemical profiling approach. Differences in tea processing resulted in differences in the chemical constituents and the color of tea infusions. Human biological responses to pu-erh tea ingestion were also studied by using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS) in conjunction with multivariate statistical techniques. Metabolic alterations during and after pu-erh tea ingestion were characterized by increased urinary excretion of 5-hydroxytryptophan, inositol, and 4-methoxyphenylacetic acid, along with reduced excretion of 3-chlorotyrosine and creatinine. This study highlights the potential for metabonomic technology to assess nutritional interventions and is an important step toward a full understanding of pu-erh tea and its influence on human metabolism. PMID:19320437

  5. [The mechanisms of weight-cutting effect and bioactive components in Pu-erh tea].

    PubMed

    Zou, Xiao-Jv; Ding, Yi-Hong; Liang, Bin

    2012-08-01

    Originally grown and produced in southern of Yunnan, China, Pu-erh tea has a long history and carries rich cultural connotations. Consumption of Pu-erh has been thought to possess numerous health benefits including weight-loss, lowering of blood glucose levels, and preventing cardiovascular diseases. Research on humans, rodents, and cell lines have each confirmed that Pu-erh tea indeed displays weight-loss and blood lipid lowering effects. The main bioactive components, such as theabrownin (TB), polysaccharides, polyphenols, and statins, may down-regulate the biosynthesis of fat and up-regulate the oxidation of fat to cut weight and reduce the content of lipids in blood. Here, we summarize current progress on understanding the mechanisms and bioactive components of Pu-erh's weight-cutting effects as well as highlighting current weaknesses in the field in order to suggest possible solutions for future research on Pu-erh tea.

  6. TEM identification of subsurface phases in ternary U-Pu-Zr fuel

    NASA Astrophysics Data System (ADS)

    Aitkaliyeva, Assel; Madden, James W.; Papesch, Cynthia A.; Cole, James I.

    2016-05-01

    Phases and microstructure in as-cast, annealed at 850 °C, and subsequently cooled U-23Pu-9Zr fuel were characterized using scanning and transmission electron microscopy techniques. SEM examination shows formation of three phases in the alloy that were identified in TEM using selective area diffraction pattern analysis: α-Zr globular and elongated δ-UZr2 inclusions and a thick oxide layer formed on top of β-Pu phase, which has been initially assumed to be ζ-(U, Pu). However, further examination of the cross-sectional TEM specimens identified the matrix phases as δ-UZr2, β-Pu, and (U, Zr)ht. Two types of inclusions were observed in the immediate vicinity of the specimen surface and they were consistent with α-Zr and ζ-(U, Pu).

  7. Comparative skeletal distribution of Am and Pu in man, monkey, and baboon

    SciTech Connect

    Lynch, T.P.; Kathren, R.L.; Dagle, G.E.; McInroy, J.F. )

    1989-01-01

    The skeletal distribution of Am and Pu in four human cases was compared with the skeletal distributions of these radioelements in baboons and monkeys. Excellent agreement was noted among the four human cases; data were available for Am in all four and Pu in three. A statistically significant correlation was found between the {sup 241}Am and {sup 239}Pu + {sup 240}Pu skeletal distributions in the humans and those in nonhuman primates. Trabecular bone had the highest concentrations of {sup 241}Am and {sup 239+240}Pu in humans, baboons, and monkeys. Scaling factors are proposed to convert the percentages of skeletal activity in animal bones to the corresponding percentages in the bones of the human skeleton.

  8. Sorption of Pu(IV) from nitric acid by bifunctional anion-exchange resins

    SciTech Connect

    Bartsch, R.A.; Zhang, Z.Y.; Elshani, S.; Zhao, W.; Jarvinen, G.D.; Barr, M.E.; Marsh, S.F.; Chamberlin, R.M.

    1999-06-01

    Anion exchange is attractive for separating plutonium because the Pu(IV) nitrate complex is very strongly sorbed and few other metal ions form competing anionic nitrate complexes. The major disadvantage of this process has been the unusually slow rate at which the Pu(IV) nitrate complex is sorbed by the resin. The paper summarizes the concept of bifunctional anion-exchange resins, proposed mechanism for Pu(IV) sorption, synthesis of the alkylating agent, calculation of K{sub d} values from Pu(IV) sorption results, and conclusions from the study of Pu(IV) sorption from 7M nitric acid by macroporous anion-exchange resins including level of crosslinking, level of alkylation, length of spacer, and bifunctional vs. monofunctional anion-exchange resins.

  9. PU. 1 is not essential for early myeloid gene expression but is required for terminal myeloid differentiation.

    PubMed

    Olson, M C; Scott, E W; Hack, A A; Su, G H; Tenen, D G; Singh, H; Simon, M C

    1995-12-01

    We have previously shown using gene targeting that PU.1 is essential for the development of lymphoid and myeloid lineages during fetal liver hematopoiesis. We now show that PU.1 is required for the maturation of yolk sac-derived myeloid progenitors and for the differentiation of ES cells into macrophages. The role of PU.1 in regulating target genes, thought to be critical in the development of monocytes and granulocytes, has been analyzed. Early genes such as GM-CSFR, G-CSFR, and myeloperoxidase are expressed in PU.1-/- embryos and differentiated PU.1-/- ES cells. However, the expression of genes associated with terminal myeloid differentiation (CD11b, CD64, and M-CSFR) is eliminated in differentiated PU.1-/- ES cells. Development of macrophages is restored with the introduction of a PU.1 cDNA regulated by its own promoter. The PU.1-/- ES cells represent an important model for analyzing myeloid cell development.

  10. U.S.-Russian experts NATO collaborative research grant exchange visit meeting on excess Pu ceramics formulations and characterizations

    SciTech Connect

    Jardine, L.J., LLNL

    1998-11-24

    This document contains the agenda and meeting notes. Topics of discussion included US Pu disposition ceramics activities, Russian experience and proposals in Pu ceramics, and development of possible Russian ceramic proposals or collaborations.

  11. Preparation and characterization of {sup 238}Pu-ceramics for radiation damage experiments

    SciTech Connect

    DM Strachan; RD Scheele; WC Buchmiller; JD Vienna; RL Sell; RJ Elovich

    2000-06-15

    As a result of treaty agreements between Russia and the US, portions of their respective plutonium and nuclear weapons stockpiles have been declared excess. In support of the US Department of Energy's 1998 decision to pursue immobilization of a portion of the remaining Pu in a titanate-based ceramic, the authors prepared nearly 200 radiation-damage test specimens of five Pu- and {sup 238}Pu-ceramics containing 10 mass% Pu to determine the effects of irradiation from the contained Pu and U on the ceramic. The five Pu-ceramics were (1) phase-pure pyrochlore [ideally, Ca(U, Pu)Ti{sub 2}O{sub 7}], (2) pyrochlore-rich baseline, (3) pyrochlore-rich baseline with impurities, (4) phase-pure zirconolite [ideally Ca(U, Pu)Ti{sub 2}O{sub 7}], and (5) a zirconolite-rich baseline. These ceramics were prepared with either normal weapons-grade Pu, which is predominantly {sup 239}Pu, or {sup 238}Pu. The {sup 238}Pu accelerates the radiation damage relative to the {sup 239}Pu because of its much higher specific activity. The authors were unsuccessful in preparing phase-pure (Pu, U) brannerite, which is the third crystalline phase present in the baseline immobilization form. Since these materials will contain {approximately}10 mass% Pu and about 20 mass% U, radiation damage to the crystalline structure of these materials will occur overtime. As the material becomes damaged from the decay of the Pu and U, it is possible for the material to swell as both the alpha particles and recoiling atoms rupture chemical bonds within the solid. As the material changes density, cracking, perhaps in the form of microcracks, may occur. If cracking occurs in ceramic that has been placed in a repository, the calculated rate of radionuclide release if the can has corroded would increase proportionately to the increase in surface area. To investigate the effects of radiation damage on the five ceramics prepared, the authors are storing the specimens at 20, 125, and 250 C until the {sup 238}Pu specimens

  12. Nrf2 regulates PU.1 expression and activity in the alveolar macrophage.

    PubMed

    Staitieh, Bashar S; Fan, Xian; Neveu, Wendy; Guidot, David M

    2015-05-15

    Alveolar macrophage (AM) immune function depends on the activation of the transcription factor PU.1 by granulocyte macrophage colony-stimulating factor. We have determined that chronic alcohol ingestion dampens PU.1 signaling via an unknown zinc-dependent mechanism; specifically, although PU.1 is not known to be a zinc-dependent transcription factor, zinc treatment reversed alcohol-mediated dampening of PU.1 signaling. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a zinc-dependent basic leucine zipper protein essential for antioxidant defenses, is also impaired by chronic alcohol ingestion and enhanced by zinc treatment. We hypothesized that the response of PU.1 to zinc treatment may result from the action of Nrf2 on PU.1. We first performed Nrf2/PU.1 protein coimmunoprecipitation on a rat AM cell line (NR8383) and found no evidence of protein-protein interactions. We then found evidence of increased Nrf2 binding to the PU.1 promoter region by chromatin immunoprecipitation. We next activated Nrf2 using either sulforaphane or an overexpression vector and inhibited Nrf2 with silencing RNA to determine whether Nrf2 could actively regulate PU.1. Nrf2 activation increased protein expression of both factors as well as gene expression of their respective downstream effectors, NAD(P)H dehydrogenase[quinone] 1 (NQO1) and cluster of differentiation antigen-14 (CD14). In contrast, Nrf2 silencing decreased the expression of both proteins, as well as gene expression of their effectors. Activating and inhibiting Nrf2 in primary rat AMs resulted in similar effects. Taken together, these findings suggest that Nrf2 regulates the expression and activity of PU.1 and that antioxidant response and immune activation are coordinately regulated within the AM.

  13. Developing the Pulsed Fission-Fusion (PuFF) Engine

    NASA Technical Reports Server (NTRS)

    Adams, Robert B.; Cassibry, Jason; Bradley, David; Fabisinski, Leo; Statham, Geoffrey

    2014-01-01

    In September 2013 the NASA Innovative Advanced Concept (NIAC) organization awarded a phase I contract to the PuFF team. Our phase 1 proposal researched a pulsed fission-fusion propulsion system that compressed a target of deuterium (D) and tritium (T) as a mixture in a column, surrounded concentrically by Uranium. The target is surrounded by liquid lithium. A high power current would flow down the liquid lithium and the resulting Lorentz force would compress the column by roughly a factor of 10. The compressed column would reach criticality and a combination of fission and fusion reactions would occur. Our Phase I results, summarized herein, review our estimates of engine and vehicle performance, our work to date to model the fission-fusion reaction, and our initial efforts in experimental analysis.

  14. Gamma-ray Output Spectra from 239 Pu Fission

    DOE PAGES

    Ullmann, John

    2015-05-25

    Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-raymore » multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.« less

  15. Gamma-ray Output Spectra from 239Pu Fission

    NASA Astrophysics Data System (ADS)

    Ullmann, John

    2015-05-01

    Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-ray multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.

  16. 137Cs, 239+240Pu and 240Pu/239Pu atom ratios in the surface waters of the western North Pacific Ocean, eastern Indian Ocean and their adjacent seas.

    PubMed

    Yamada, Masatoshi; Zheng, Jian; Wang, Zhong-Liang

    2006-07-31

    Surface seawater samples were collected along the track of the R/V Hakuho-Maru cruise (KH-96-5) from Tokyo to the Southern Ocean. The (137)Cs activities were determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas, the eastern Indian Ocean, the Bay of Bengal, the Andaman Sea, and the South China Sea. The (137)Cs activities showed a wide variation with values ranging from 1.1 Bq m(-3) in the Antarctic Circumpolar Region of the Southern Ocean to 3 Bq m(-3) in the western North Pacific Ocean and the South China Sea. The latitudinal distributions of (137)Cs activity were not reflective of that of the integrated deposition density of atmospheric global fallout. The removal rates of (137)Cs from the surface waters were roughly estimated from the two data sets of Miyake et al. [Miyake Y, Saruhashi K, Sugimura Y, Kanazawa T, Hirose K. Contents of (137)Cs, plutonium and americium isotopes in the Southern Ocean waters. Pap Meteorol Geophys 1988;39:95-113] and this study to be 0.016 yr(-1) in the Sulu and Indonesian Seas, 0.033 yr(-1) in the Bay of Bengal and Andaman Sea, and 0.029 yr(-1) in the South China Sea. These values were much lower than that in the coastal surface water of the western Northwest Pacific Ocean. This was likely due to less horizontal and vertical mixing of water masses and less scavenging. (239+240)Pu activities and (240)Pu/(239)Pu atom ratios were also determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas and the South China Sea. The (240)Pu/(239)Pu atom ratios ranged from 0.199+/-0.026 to 0.248+/-0.027 on average, and were significantly higher than the global stratospheric fallout ratio of 0.18. The contributions of the North Pacific Proving Grounds close-in fallout Pu were estimated to be 20% for the western North Pacific Ocean, 39% for the Sulu and Indonesian Seas and 42% for the South China Sea by using the two end-member mixing model. The higher (240)Pu/(239)Pu

  17. 137Cs, 239+240Pu and 240Pu/239Pu atom ratios in the surface waters of the western North Pacific Ocean, eastern Indian Ocean and their adjacent seas.

    PubMed

    Yamada, Masatoshi; Zheng, Jian; Wang, Zhong-Liang

    2006-07-31

    Surface seawater samples were collected along the track of the R/V Hakuho-Maru cruise (KH-96-5) from Tokyo to the Southern Ocean. The (137)Cs activities were determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas, the eastern Indian Ocean, the Bay of Bengal, the Andaman Sea, and the South China Sea. The (137)Cs activities showed a wide variation with values ranging from 1.1 Bq m(-3) in the Antarctic Circumpolar Region of the Southern Ocean to 3 Bq m(-3) in the western North Pacific Ocean and the South China Sea. The latitudinal distributions of (137)Cs activity were not reflective of that of the integrated deposition density of atmospheric global fallout. The removal rates of (137)Cs from the surface waters were roughly estimated from the two data sets of Miyake et al. [Miyake Y, Saruhashi K, Sugimura Y, Kanazawa T, Hirose K. Contents of (137)Cs, plutonium and americium isotopes in the Southern Ocean waters. Pap Meteorol Geophys 1988;39:95-113] and this study to be 0.016 yr(-1) in the Sulu and Indonesian Seas, 0.033 yr(-1) in the Bay of Bengal and Andaman Sea, and 0.029 yr(-1) in the South China Sea. These values were much lower than that in the coastal surface water of the western Northwest Pacific Ocean. This was likely due to less horizontal and vertical mixing of water masses and less scavenging. (239+240)Pu activities and (240)Pu/(239)Pu atom ratios were also determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas and the South China Sea. The (240)Pu/(239)Pu atom ratios ranged from 0.199+/-0.026 to 0.248+/-0.027 on average, and were significantly higher than the global stratospheric fallout ratio of 0.18. The contributions of the North Pacific Proving Grounds close-in fallout Pu were estimated to be 20% for the western North Pacific Ocean, 39% for the Sulu and Indonesian Seas and 42% for the South China Sea by using the two end-member mixing model. The higher (240)Pu/(239)Pu

  18. Helium release from 238PuO2 fuel particles

    NASA Astrophysics Data System (ADS)

    El-Genk, Mohamed S.; Tournier, Jean-Michel

    2000-01-01

    Coated plutonia fuel particles have recently been proposed for potential use in future space exploration missions that employ radioisotope power systems and/or radioisotope heater units (RHUs). The design of this fuel form calls for full retention of the helium generated by the natural radioactive decay of 238Pu, with the aid of a strong zirconium carbide coating. This paper reviews the potential release mechanisms of helium in small-grain (7-40 μm) plutonia pellets currently being used in the General Purpose Heat Source (GPHS) modules and RHUs, during both steady-state and transient heating conditions. The applicability of these mechanisms to large-grain and polycrystalline 238PuO2 fuel kernels is examined and estimates of helium release during a re-entry heating pulse up to 1723 K are presented. These estimates are based on the reported data for fission gas release from granular and monocrystal UO2 fuel particles irradiated at isothermal conditions up to 6.4 at.% burnup and 2030 K. It is concluded that the helium release fraction from large-grain (>=300 μm) plutonia fuel kernels heated up to 1723 K could be less than 7%, compared to ~80% from small-grain (7-40 μm) fuel. The helium release fraction from polycrystalline plutonia kernels fabricated using Sol-Gel techniques could be even lower. Sol-Gel fabrication processes are favored over powder metallurgy, because of their high precision and excellent reproducibility and the absence of a radioactive dust waste stream, significantly reducing the fabrication and post-fabrication clean-up costs. .

  19. Mechanical resuspension of /sup 239/Pu from unpaved roads

    SciTech Connect

    Hodgin, C.R.

    1982-01-01

    The impacts of resuspended plutonium from two unpaved roads at the Rocky Flats Plant on nearby air samplers were investigated. Because the sources were complex fugitive dust emitters and because of the small source-receptor distances, traditional dispersion modeling techniques could not be employed. Thus two specialized techniques, one for fugitive dust emissions and one for near distance dispersion, were developed and used to calculate atmospheric dust concentrations at the subject air samplers. Atmospheric /sup 239/Pu impacts were then determined from measurements of plutonium concentrations in the resuspendible dust on the road surfaces. As a final step in the process the calculated plutonium impacts were compared to the 1980 annual average /sup 239/Pu concentration at four samplers. The impact calculated for the Gunnery Range Road represented 2.1 percent of the observed annual concentration, with a 95 percent confidence interval of 1.1 to 7.9 percent. The Southeast Perimeter Road produced a more substantial effect with a point estimate of 3.8 percent. The 95 percent confidence interval for this source was 2.0 to 9.1 percent. The combined impact of the two roads on the subject samplers was 5.9 percent of the observed plutonium concentration, with a 95 percent confidence interval of 3.2 to 17.0 percent. Thus it was shown that fugitive plutonium emissions from the Gunnery Range Road and Southeast Perimeter Road are not substantial contributors to the plutonium concentrations observed at the subject samplers. Even an increase in dust control efficiency to 90 percent (as with paving) would result in only a four percent decrease in the overall atmosperic plutonium concentration at the site.

  20. Consistent Data Assimilation of Isotopes: 242Pu and 105Pd

    SciTech Connect

    G. Palmiotti; H. Hiruta; M. Salvatores

    2012-09-01

    In this annual report we illustrate the methodology of the consistent data assimilation that allows to use the information coming from integral experiments for improving the basic nuclear parameters used in cross section evaluation. A series of integral experiments are analyzed using the EMPIRE evaluated files for 242Pu and 105Pd. In particular irradiation experiments (PROFIL-1 and -2, TRAPU-1, -2 and -3) provide information about capture cross sections, and a critical configuration, COSMO, where fission spectral indexes were measured, provides information about fission cross section. The observed discrepancies between calculated and experimental results are used in conjunction with the computed sensitivity coefficients and covariance matrix for nuclear parameters in a consistent data assimilation. The results obtained by the consistent data assimilation indicate that not so large modifications on some key identified nuclear parameters allow to obtain reasonable C/E. However, for some parameters such variations are outside the range of 1 s of their initial standard deviation. This can indicate a possible conflict between differential measurements (used to calculate the initial standard deviations) and the integral measurements used in the statistical data adjustment. Moreover, an inconsistency between the C/E of two sets of irradiation experiments (PROFIL and TRAPU) is observed for 242Pu. This is the end of this project funded by the Nuclear Physics Program of the DOE Office of Science. We can indicate that a proof of principle has been demonstrated for a few isotopes for this innovative methodology. However, we are still far from having explored all the possibilities and made this methodology to be considered proved and robust. In particular many issues are worth further investigation: • Non-linear effects • Flexibility of nuclear parameters in describing cross sections • Multi-isotope consistent assimilation • Consistency between differential and integral

  1. Chronic cigarette smoke exposure increases the pulmonary retention and radiation dose of {sup 239}Pu inhaled as {sup 239}PuO{sub 2} by F344 rats

    SciTech Connect

    Finch, G.L.; Lundgren, D.L.; Barr, E.B.; Chen, B.T.; Griffith, W.C.; Hobbs, C.H.; Hoover, M.D.; Nikula, K.J.; Mauderly, J.L.

    1998-12-01

    As a portion of a study to examine how chronic cigarette smoke exposure might alter the risk of lung tumors from inhaled {sup 239}PuO{sub 2} in rats, the effects of smoke exposure on alpha-particle lung dosimetry over the life-span of exposed rats were determined. Male and female rats were exposed to inhaled {sup 239}PuO{sub 2} alone or in combination with cigarette smoke. Animals exposed to filtered air along served as controls for the smoke exposure. Whole-body exposure to mainstream smoke diluted to concentrations of either 100 or 250 mg total particulate matter m{sup {minus}3} began at 6 wk of age and continued for 6 h d{sup {minus}1}, 5 d wk{sup {minus}1}, for 30 mo. A single, pernasal, acute exposure to {sup 239}PuO{sub 2} was given to all rats at 12 wk of age. Exposure to cigarette smoke caused decreased body weight gains in a concentration dependent manner. Lung-to-body weight ratios were increased in smoke-exposed rats. Rats exposed to cigarette smoke before the {sup 239}PuO{sub 2} exposure deposited less {sup 239}Pu in the lung than did controls. Except for male rats exposed to LCS, exposure to smoke retarded the clearance of {sup 239}Pu from the lung compared to control rats through study termination at 870 d after {sup 239}PuO{sub 2} exposure. Radiation doses to lungs were calculated by sex and by exposure group for rats on study for at least 360 d using modeled body weight changes, lung-to-body weight ratios, and standard dosimetric calculations. For both sexes, estimated lifetime radiation doses from the time of {sup 239}PuO{sub 2} exposure to death were 3.8 Gy, 4.4 Gy, or 6.7 Gy for the control, LCS, or HCS exposure groups, respectively. Assuming an approximately linear dose-response relationship between radiation dose and lung neoplasm incidence, approximate increases of 20% or 80% in tumor incidence over controls would be expected in rats exposed to {sup 239}PuO{sub 2} and LCS or {sup 239}PuO{sub 2} and HCS, respectively.

  2. Adipocyte expression of PU.1 transcription factor causes insulin resistance through upregulation of inflammatory cytokine gene expression and ROS production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have reported previously that ETS family transcription factor PU.1 is expressed in mature adipocytes of white adipose tissue. PU.1 expression is increased greatly in mouse models of genetic or diet-induced obesity. Here, we show that PU.1 expression is increased only in visceral but not subcutane...

  3. Research of water-base nano-PU paint for heat insulation

    NASA Astrophysics Data System (ADS)

    Jwo, Ching-Song; Jeng, Lung-Yue; Cheng, Ho; Chen, Sih-Li

    2008-12-01

    The purpose of this study is to research and produce water-base nano-PU paint with energy conservation, environmental consciousness and high efficiency of heat insulation, which can be enhance the traditional PU paint for performance improvement of heat insulation and range of application. In this study, research will be held on the two-stage synthesis method. The SiO2 nanoparticles are added into the water-base PU paint to improve the properties of traditional PU paint. Next, the fundamental properties of this paint, including water resistance, weather rsistance, weak acid solvent resistance, and heat insulation rate, will be measured and analyzed, and the performance of heat insulation will be evaluated in order to confirm the performance and practicability of the heat insulation of water-base nano-PU paint in this study. The experimental results show that for the SiO2/W-PU composite nanopaint prepared by two-stage synthesis method, the dispersion of SiO2 powder in the water-base PU (W-PU) paint is even. For the SiO2/W-PU nanocomposite paint prepared by adding SiO2 powder at 8% wt. to the marketed water-base PU, the water absorption of its experimental sample is enhanced by around 10.1 times, whereas its weak acid dissolve erosion rate is increased by 3.3 times. However, the average heat insulation rate in the thermal properties is also increased, increasing around 24.22% for the W-PU paint without SiO2 powder. Through the multilayered coating construction, the water-base nano-PU paint added with SiO2 powder can be used on any facility of heat insulation, including vehicle, safety helmet, umbrella, drapes, and outer wall of building. The newly developed water-base nano-PU paint with high thermal resistance is especially suitable for application to the shell coating of air conditioner and cooling tower,. Due to the better thermal resistance of this nanopaint, the problems of poor heat transfer and temperature rise of cooling water caused by direct sunlight can be

  4. Concentrations of 137Cs, 90Sr, 108m Ag, 239+240 Pu and atom ratio of 240Pu/239Pu in tanner crabs, Chionoecetes japonicus and Chionoecetes opilio collected around Japan.

    PubMed

    Morita, Takami; Ohtsuka, Yoshihito; Fujimoto, Ken; Minamisako, Yoko; Iida, Rika; Nakamura, Masae; Kayama, Toshiharu

    2010-12-01

    The anthropogenic radionuclides, (137)Cs, (90)Sr, (108m)Ag, (239+240)Pu, were measured in two Chionoecetes species, red queen crab (Chionoecetes japonicus) and snow crab (Chionoecetes opilio) collected around Japan during 1996-2007. There was no increase in the concentrations of these radionuclides and no large variation of the atom ratio of (240)Pu/(239)Pu during this research period. These results indicated that the source of the radionuclides was not the radioactive wastes dumped by the former USSR and Russia and originated from past nuclear weapon tests. The higher atom ratio in the crab species than that from global fallout would be contributed by the Pacific Proving Grounds close-in fallout. The variability of the concentration of radionuclides in the crab species would result from the variability of the composition and quantity in the diet. However, the decrease in the concentration of radionuclides with sampling depth would depend on the concentration in the seawater and diet.

  5. Measurement of 239Pu in soil and plants in the Nishiyama District of Nagasaki.

    PubMed

    Okajima, S; Shimasaki, T; Kubo, T

    1990-05-01

    Nishiyama district in Nagasaki is located approximately 3000 m east of the hypocenter of the atomic bomb that was dropped on 9 August 1945. This district is also known as an area where there was a concentrated radioactive fallout with the black rain that was carried by a westerly wind. The Nagasaki atomic bomb was a Pu bomb, and the fallout must have included 239Pu without fission in addition to fission products. The presence of 239Pu in Nishiyama district has been confirmed previously. In this study, the distribution of 239 + 240Pu concentration in the uncultivated soil and the transfer factor of 239 + 240Pu to agricultural products in Nishiyama district were examined. The concentration of 239 + 240Pu in the uncultivated soil was 20 Bq kg-1, which was approximately eight times as high as that in the control districts. The transfer factor of 239 + 240Pu to agricultural products was 10(-4) - 10(-3), which was 1/100-1/200 of that of 137Cs.

  6. The coprecipitation of Pu and other radionuclides with CaCO[sub 3

    SciTech Connect

    Meece, D.E.; Benninger, L.K. )

    1993-04-01

    The record of fallout plutonium concentrations in annual bands of corals is strikingly similar to the record of atmospheric deposition of [sup 90]Sr. This similarity implies that corals may incorporate Pu from seawater with a constant partition coefficient (constant discrimination). To investigate physicochemical aspects of Pu incorporation, the following have been coprecipitated with CaCO[sub 3] (calcite and aragonite): oxidized and reduced Pu; americium, thorium, and uranium as analogs to Pu oxidation states (III, IV, VI), respectively; and [sup 210]Pb as a particle-reactive nuclide which may be incorporated by corals with constant discrimination. Americium, thorium, and lead adsorb onto both calcite and aragonite, with more than 99% of the recovered activity found associated with the solids. Uranium exhibits a behavior consistent with lattice substitution. Partition coefficients for U in aragonite range from 1.8 to 9.8 and vary inversely with pH and/or rate of precipitation. The partition coefficient for U in calcite is less than 0.2 and may be as low as 0.046. Reduced Pu sorbs with 3 to 4% remaining in solution. Oxidized Pu may both sorb and coprecipitate. The coral record for Pb and U results primarily from biological, rather than physicochemical, effects; it is likely that the PU coral record also reflects biological discrimination. 50 refs., 4 figs., 5 tabs.

  7. Criticality Safety Controls for 55-Gallon Drums with a Mass Limit of 200 grams Pu-239

    SciTech Connect

    Chou, P

    2011-12-14

    The following 200-gram Pu drum criticality safety controls are applicable to RHWM drum storage operations: (1) Mass (Fissile/Pu) - each 55-gallon drum or its equivalent shall be limited to 200 gram Pu or Pu equivalent; (2) Moderation - Hydrogen materials with a hydrogen density greater than that (0.133 g H/cc) of polyethylene and paraffin are not allowed and hydrogen materials with a hydrogen density no greater than that of polyethylene and paraffin are allowed with unlimited amounts; (3) Interaction - a spacing of 30-inches (76 cm) is required between arrays and 200-gram Pu drums shall be placed in arrays for 200-gram Pu drums only (no mingling of 200-gram Pu drums with other drums not meeting the drum controls associated with the 200-gram limit); (4) Reflection - no beryllium and carbon/graphite (other than the 50-gram waiver amount) is allowed, (note that Nat-U exceeding the waiver amount is allowed when its U-235 content is included in the fissile mass limit of 200 grams); and (5) Geometry - drum geometry, only 55-gallon drum or its equivalent shall be used and array geometry, 55-gallon drums are allowed for 2-high stacking. Steel waste boxes may be stacked 3-high if constraint.

  8. Change Spectroscopic, thermal and mechanical studies of PU/PVC blends

    NASA Astrophysics Data System (ADS)

    Hezma, A. M.; Elashmawi, I. S.; Rajeh, A.; Kamal, Mustafa

    2016-08-01

    Blends of polyurethane (PU) and polyvinyl chloride (PVC) with different concentrations were prepared by casting method. The effects of PU on PVC blends was examined by Fourier transform-infrared (FTIR), Ultra-violet visible studies (UV/VIS.), X-ray diffraction (XRD), Thermogravimetric (TGA), Differential scanning calorimetry (DSC), and mechanical properties (stress-strain curve). The interaction between PU and PVC was examined by FT-IR through the absorbance of the N-H groups and was correlated to mechanical/thermal properties. Ultra-violet visible said that optical energy gap decrease with increasing concentration of PU. Differential scanning calorimetry results was observed a single glass transition temperature (Tg) for blends this confirming existence miscibility within the blends. The causes for best thermal stability of some blends may be described by measurements of interactions between C=O groups of PU and the α-hydrogen of PVC or a dipole-dipole -C=O..Cl-C- interactions. Significant alterations in FTIR, X-ray and DSC examination shows an interactions between blends had good miscibility. X-ray shows some alterations in the intensity with additional PU. PU change the mechanical behavior of PVC through of the blends. When polyurethane content increase causes polyvinyl chloride tensile strength decreases and elongation at break increase.

  9. Melting behavior of (Th,U)O2 and (Th,Pu)O2 mixed oxides

    NASA Astrophysics Data System (ADS)

    Ghosh, P. S.; Kuganathan, N.; Galvin, C. O. T.; Arya, A.; Dey, G. K.; Dutta, B. K.; Grimes, R. W.

    2016-10-01

    The melting behaviors of pure ThO2, UO2 and PuO2 as well as (Th,U)O2 and (Th,Pu)O2 mixed oxides (MOX) have been studied using molecular dynamics (MD) simulations. The MD calculated melting temperatures (MT) of ThO2, UO2 and PuO2 using two-phase simulations, lie between 3650-3675 K, 3050-3075 K and 2800-2825 K, respectively, which match well with experiments. Variation of enthalpy increments and density with temperature, for solid and liquid phases of ThO2, PuO2 as well as the ThO2 rich part of (Th,U)O2 and (Th,Pu)O2 MOX are also reported. The MD calculated MT of (Th,U)O2 and (Th,Pu)O2 MOX show good agreement with the ideal solidus line in the high thoria section of the phase diagram, and evidence for a minima is identified around 5 atom% of ThO2 in the phase diagram of (Th,Pu)O2 MOX.

  10. Langerhans cells are generated by two distinct PU.1-dependent transcriptional networks.

    PubMed

    Chopin, Michaël; Seillet, Cyril; Chevrier, Stéphane; Wu, Li; Wang, Hongsheng; Morse, Herbert C; Belz, Gabrielle T; Nutt, Stephen L

    2013-12-16

    Langerhans cells (LCs) are the unique dendritic cells found in the epidermis. While a great deal of attention has focused on defining the developmental origins of LCs, reports addressing the transcriptional network ruling their differentiation remain sparse. We addressed the function of a group of key DC transcription factors-PU.1, ID2, IRF4, and IRF8-in the establishment of the LC network. We show that although steady-state LC homeostasis depends on PU.1 and ID2, the latter is dispensable for bone marrow-derived LCs. PU.1 controls LC differentiation by regulating the expression of the critical TGF-β responsive transcription factor RUNX3. PU.1 directly binds to the Runx3 regulatory elements in a TGF-β-dependent manner, whereas ectopic expression of RUNX3 rescued LC differentiation in the absence of PU.1 and promoted LC differentiation from PU.1-sufficient progenitors. These findings highlight the dual molecular network underlying LC differentiation, and show the central role of PU.1 in these processes.

  11. The interception and retention of 238Pu deposition by orange trees.

    PubMed

    Pinder, J E; Adriano, D C; Ciravolo, T G; Doswell, A C; Yehling, D M

    1987-06-01

    Radioisotope thermoelectric generators (RTG) transform the heat produced during the alpha decay of 238Pu into electrical energy for use by deep-space probes, such as the Voyager spacecraft, which have returned images and other data from Jupiter, Saturn and Uranus. Future missions involving RTGs may be launched aboard the space shuttle, and there is a remote possibility that an explosion of liquid-hydrogen and liquid-oxygen fuel could rupture the RTGs and disperse 238Pu into the atmosphere over central Florida. Research was performed to determine the potential transport to man of atmospherically dispersed Pu via contaminated orange fruits. The results indicate that the major contamination of oranges would result from the interception and retention of 238Pu deposition by fruits. The resulting surface contamination could enter human food chains through transfer to internal tissues during peeling or in the reconstituted juices and flavorings made from orange skins. The interception of 238Pu deposition by fruits is especially important because the results indicate no measurable loss of Pu from fruit surfaces through time or with washing. Approximately 1% of the 238Pu deposited onto an orange grove would be harvested in the year following deposition.

  12. Interception and retention of /sup 238/Pu deposition by orange trees

    SciTech Connect

    Pinder, J.E. III; Adriano, D.C.; Ciravolo, T.G.; Doswell, A.C.; Yehling, D.M.

    1987-06-01

    Radioisotope thermoelectric generators (RTG) transform the heat produced during the alpha decay of /sup 238/Pu into electrical energy for use by deep-space probes, such as the Voyager spacecraft, which have returned images and other data from Jupiter, Saturn and Uranus. Future missions involving RTGs may be launched aboard the space shuttle, and there is a remote possibility that an explosion of liquid-hydrogen and liquid-oxygen fuel could rupture the RTGs and disperse /sup 238/Pu into the atmosphere over central Florida. Research was performed to determine the potential transport to man of atmospherically dispersed Pu via contaminated orange fruits. The results indicate that the major contamination of oranges would result from the interception and retention of /sup 238/Pu deposition by fruits. The resulting surface contamination could enter human food chains through transfer to internal tissues during peeling or in the reconstituted juices and flavorings made from orange skins. The interception of /sup 238/Pu deposition by fruits is especially important because the results indicate no measurable loss of Pu from fruit surfaces through time or with washing. Approximately 1% of the /sup 238/Pu deposited onto an orange grove would be harvested in the year following deposition.

  13. Minimal PU.1 reduction induces a preleukemic state and promotes development of acute myeloid leukemia.

    PubMed

    Will, Britta; Vogler, Thomas O; Narayanagari, Swathi; Bartholdy, Boris; Todorova, Tihomira I; da Silva Ferreira, Mariana; Chen, Jiahao; Yu, Yiting; Mayer, Jillian; Barreyro, Laura; Carvajal, Luis; Neriah, Daniela Ben; Roth, Michael; van Oers, Johanna; Schaetzlein, Sonja; McMahon, Christine; Edelmann, Winfried; Verma, Amit; Steidl, Ulrich

    2015-10-01

    Modest transcriptional changes caused by genetic or epigenetic mechanisms are frequent in human cancer. Although loss or near-complete loss of the hematopoietic transcription factor PU.1 induces acute myeloid leukemia (AML) in mice, a similar degree of PU.1 impairment is exceedingly rare in human AML; yet, moderate PU.1 inhibition is common in AML patients. We assessed functional consequences of modest reductions in PU.1 expression on leukemia development in mice harboring DNA lesions resembling those acquired during human stem cell aging. Heterozygous deletion of an enhancer of PU.1, which resulted in a 35% reduction of PU.1 expression, was sufficient to induce myeloid-biased preleukemic stem cells and their subsequent transformation to AML in a DNA mismatch repair-deficient background. AML progression was mediated by inhibition of expression of a PU.1-cooperating transcription factor, Irf8. Notably, we found marked molecular similarities between the disease in these mice and human myelodysplastic syndrome and AML. This study demonstrates that minimal reduction of a key lineage-specific transcription factor, which commonly occurs in human disease, is sufficient to initiate cancer development, and it provides mechanistic insight into the formation and progression of preleukemic stem cells in AML.

  14. EnEnvironmental Mobility of Pu(IV) in the Presence of Ethylenediaminetetraacetic Acid: Myth or Reality

    SciTech Connect

    Rai, Dhanpat; Moore, Dean A.; Rosso, Kevin M.; Felmy, Andrew R.; Bolton, Harvey

    2008-07-01

    Ethylenediaminetetracetic acid (EDTA), which was co-disposed with Pu at several U. S. Department of Energy sites, has been reported to enhance the solubility and transport of Pu. It is generally assumed that this enhanced transport of Pu in geologic environments is a result of complexation of Pu(IV) with EDTA. However, the fundamental bases for this assumption have never been fully explored. Whether EDTA can mobilize Pu(IV) in geologic environments is dependent on many factors, chief among them are not only the complexation constants of Pu with EDTA and dominant oxidation state and the nature of Pu solids, but also 1) the complexation constants of environmentally important metal ions (e.g. Fe, Al, Ca, Mg) that compete with Pu for EDTA and 2) EDTA interactions with geomedia (e.g., adsorption, biodegradation) that reduce effective EDTA concentrations available for complexation. Extensive studies over a large range of pH values (1 to 14) and EDTA concentrations (0.0001 to 0.01 M) as a function of time were conducted on the solubility of 2-line ferrihydrite (Fe(OH)3(s)), PuO2(am) in the presence of different concentrations of Ca ions, and mixtures of PuO2(am) and Fe(OH)3(s). The solubility data were interpreted using Pitzer’s ion-interaction approach to determine/validate the solubility product of Fe(OH)3(s), the complexation constants of Pu(IV)-EDTA and Fe(III)-EDTA, and to determine the affect of EDTA in solubilizing Pu(IV) from PuO2(am) in the presence of Fe(III) compounds and aqueous Ca concentrations. Predictions based on these extensive fundamental data show that environmental mobility of Pu as a result of Pu(IV)-EDTA complexation as reported/implied in the literature is a myth rather than the reality.

  15. Determining site-specific drum loading criteria for storing combustible {sup 238}Pu waste

    SciTech Connect

    Marshall, R.S.; Callis, E.L.; Cappis, J.H.; Espinoza, J.M.; Foltyn, E.M.; Reich, B.T.; Smith, M.C.

    1994-02-01

    Waste containing hydrogenous-combustible material contaminated with {sup 238}Pu can generate hydrogen gas at appreciable rates through alpha radiolysis. To ensure safe transportation of WIPP drums, the limit for {sup 238}Pu-combustible waste published in the WIPP TRUPACT-11 CONTENT (TRUCON) CODES is 21 milliwafts per 55 gallon drum. This corresponds to about 45 milligrams of {sup 238}PuO{sub 2} used for satellite heat source-electrical generators. The Los Alamos waste storage site adopted a {sup 238}Pu waste storage criteria based on these TRCUCON codes. However, reviews of the content in drums of combustible waste generated during heat source assembly at Los Alamos showed the amount of {sup 238}Pu is typically much greater than 45 milligrams. It is not feasible to appreciably reduce Los Alamos {sup 238}Pu waste drum loadings without significantly increasing waste volumes or introducing unsafe practices. To address this concern, a series of studies were implemented to evaluate the applicability of the TRUCON limits for storage of this specific waste. Addressed in these evaluations were determination of the hydrogen generation rate, hydrogen diffusion rates through confinement layers and vent filters, and packaging requirements specific to Los Alamos generated {sup 238}Pu contaminated combustible waste. These studies also showed that the multiple-layer packaging practices in use at Los Alamos could be relaxed without significantly increasing the risk of contamination. Based on a model developed to predict H{sub 2} concentrations in packages and drum headspace, the site specific effective hydrogen generation rate, and hydrogen-diffusion values, and revising the waste packaging practices, we were able to raise the safe loading limit for {sup 238}Pu waste drums for on site storage to the gram levels typical of currently generated {sup 238}Pu waste.

  16. Plutonium Residue Recovery (PuRR) project quarterly progress report, April--June 1989

    SciTech Connect

    Gregg, D.W.; Hickman, R.G.; Landrum, J.H. ); Johnson, G.K.; Johnson, I.; Mulcahey, T.P.; Pierce, R.D.; Poa, D.S. )

    1989-10-20

    A material-balance flowsheet for ash-heel processing has been prepared. The major process features are (1) reduction of Pu into a calcium-zinc alloy and selective electrolytic recovery of the Pu from the alloy, (2) removal of americium as a waste, (3) concentration of nontransuranic tramp elements in a zinc waste, (4) removal of oxygen and recovery of calcium by electrolysis of CaO, and (5) zinc recycle by evaporation. Based on this idealized flowsheet, the mass of solid waste is only 62% of that of the original residue. This is accomplished by recycling virtually all the reagents and discarding the oxygen as CO and CO{sub 2}. The pyrochemical recovery of Pu from incinerator ash heel from the Rocky Flats Plant was investigated. During this period, zinc-calcium alloys were used to reduce the PuC{sub 2} in the ash. Reduction of ash heel has been attempted with zinc-calcium alloys containing 2, 6, and 10 wt% calcium after the reduction. These resulted in extractions of 95%, 97%, and 99.5%, respectively, of the Pu from the salt. Following exposure of the reduction alloy to a ZnCl{sub 2}-bearing salt, the Pu was removed effectively from the alloy; however, the Pu recovered in the salt did not complete the material balance. Experiments were made to test a calcium-zinc reference electrode against a Zn-Ca-Mg-Al liquid alloy. The results agreed well with calculated potentials, and such electrodes are promising for application to process monitoring. Calculations were made that verify that most of the americium in the molten salt is present in the divalent state when distributed between liquid Pu and NaCl-KCl. The AmCl{sub 2} activity coefficient is about 10 times that of PuCl{sub 3} in the salt mixture.

  17. Application of a canine {sup 238}Pu dosimetry model to human bioassay data

    SciTech Connect

    Hickman, A.W. Jr.

    1991-08-01

    Associated with the use of 2{sup 238}Pu in thermoelectric power sources for space probes and power supplies for cardiac devices is the potential for human exposure to {sup 238}Pu, 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 {sup 239}Pu. However, results from studies with laboratory animals have indicated that the biokinetics, and therefore the descriptive models, of {sup 238}Pu are significantly different from those for {sup 239}Pu. 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 {sup 238}Pu 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 {sup 238}Pu 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 {sup 238}Pu 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 {sup 239}Pu 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.

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

    PubMed

    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

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

    PubMed

    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

  20. Isochronal annealing of radiation damage in (alpha)- and (delta)-Pu alloys

    SciTech Connect

    McCall, S K; Fluss, M J; Chung, B W; Haire, R G

    2009-06-22

    Magnetic isochronal annealing curves were measured on specimens of self damaged {alpha}-Pu and several {delta}-Pu alloys stabilized by Ga and Am. These results are compared to one another and to isochronal resistivity annealing curves, where distinct differences are observed between the magnetic and resistive annealing for the case of {delta}-Pu. The first stage of annealing observed in the resistivity measurements is largely missing from the magnetic measurements, indicating that interstitials contribute little if any signal to the magnetization, while the onset of vacancy migration is strongly reflected in the magnetization signal.

  1. Irradiation performance of (Th,Pu)O2 fuel under Pressurized Water Reactor conditions

    NASA Astrophysics Data System (ADS)

    Boer, B.; Lemehov, S.; Wéber, M.; Parthoens, Y.; Gysemans, M.; McGinley, J.; Somers, J.; Verwerft, M.

    2016-04-01

    This paper examines the in-pile safety performance of (Th,Pu)O2 fuel pins under simulated Pressurized Water Reactor (PWR) conditions. Both sol-gel and SOLMAS produced (Th,Pu)O2 fuels at enrichments of 7.9% and 12.8% in Pu/HM have been irradiated at SCK·CEN. The irradiation has been performed under PWR conditions (155 bar, 300 °C) in a dedicated loop of the BR-2 reactor. The loop is instrumented with flow and temperature monitors at inlet and outlet, which allow for an accurate measurement of the deposited enthalpy.

  2. Characterization of (241)Pu occurrence, distribution, and bioaccumulation in seabirds from northern Eurasia.

    PubMed

    Strumińska-Parulska, Dagmara I; Skwarzec, Bogdan

    2015-05-01

    The paper presents unique data of plutonium (241)Pu study in seabirds from northern Eurasia, permanently or temporally living at the southern Baltic Sea coast. Together, ten marine birds species were examined, as follows: three species that permanently reside at the southern Baltic, four species of wintering birds, and three species of migrating birds; 366 samples were analyzed. The obtained results indicated plutonium was non-uniformly distributed in organs and tissues of analyzed seabirds. The highest (241)Pu content was found in the digestion organs and feathers, the lowest in muscles. Also, the internal radiation doses from (241)Pu were evaluated.

  3. Characterization of insoluble residues from the dissolution of irradiated (U,Pu)O{sub 2}

    SciTech Connect

    Goode, J.H.; Arwood, P.C.

    1983-05-01

    Hot-cell tests were conducted using (U,Pu)O{sub 2} fuels that had been irradiated to about 5.2 TJ/kg (U + Pu) [60 MWd/kg (U + Pu)] in an effort to characterize the insoluble residues that remained after the fuel pellets had been dissolved in HNO{sub 3} and in HNO{sub 3}-KF. The composition, particle size range, and density of the material were determined by newer analytical techniques, including spark-source mass spectrometry, neutron activation, scanning electron microscopy, and x-ray fluorescence, combined with older methods such as sedimentation and powder density by water displacement.

  4. Operation of the Oxide Washer for Water-Washing Solubles out of Impure Pu Oxide

    SciTech Connect

    Dodson, K E; Close, W L; Krikorian, O H; Summers III, H V

    2006-01-30

    An evaluation has been made for using the Oxide Washer to wash water-soluble materials out of impure Pu oxide. It is found that multiple washes are needed to reduce the water-soluble materials to very low levels in the impure Pu oxides. The removal of the wash water from the Oxide Washer is accompanied by particulates of the impure Pu oxide, which subsequently need to be filtered out. In spite of the additional filtration needed, the overall level of manpower required for processing is still only about one third of that for an all-manual operation.

  5. I-Pu-Xe dating and the relative ages of the earth and moon

    NASA Technical Reports Server (NTRS)

    Swindle, T. D.; Caffee, M. W.; Hohenberg, C. M.; Taylor, S. R.

    1986-01-01

    The ages of the earth and moon as determined by various chronometric systems are discussed with primary emphasis placed on the development of an I-Pu-Xe chronometer. Data on excess fission xenon are reviewed with attention given to the strengths and weaknesses of the assumptions required for lunar I-Pu-Xe chronometry. Using I-Pu-Xe dating, it is estimated that the retention of excess fission xenon in lunar samples began no more than 63 + or - 42 m.y. after the time of primitive meteorite formation.

  6. PU.1 Suppresses Th2 Cytokine Expression via Silencing of GATA3 Transcription in Dendritic Cells.

    PubMed

    Yashiro, Takuya; Kubo, Masato; Ogawa, Hideoki; Okumura, Ko; Nishiyama, Chiharu

    2015-01-01

    The transcription factor PU.1 is predominantly expressed in dendritic cells (DCs) and is essential for DC differentiation. Although there are several reports that PU.1 positively regulates the expression of DC-specific genes, whether PU.1 also has a suppressive effect on DCs is largely unknown. Here we demonstrate that PU.1 suppresses the expression of Th2 cytokines including IL-13 and IL-5 in bone marrow-derived DCs (BMDCs), through repression of the expression of GATA3, which is a master regulator of Th2 differentiations. When PU.1 siRNA was introduced into BMDCs, LPS-induced expression of IL-13 and IL-5 was increased along with upregulation of the constitutive expression of GATA2 and GATA3. The additional introduction of GATA3 siRNA but not of GATA2 siRNA abrogated PU.1 siRNA-mediated upregulation of IL-13 and IL-5. A chromatin immunoprecipitation assay showed that PU.1 bound to Gata3 proximal promoter region, which is more dominant than the distal promoter in driving GATA3 transcription in DCs. The degree of histone acetylation at the Gata3 promoter was decreased in PU.1 siRNA-introduced DCs, suggesting the involvement of PU.1 in chromatin modification of the Gata3 promoter. Treatment with a histone deacetylase (HDAC) inhibitor, trichostatin A, increased the degree of histone H3 acetylation at the Gata3 promoter and induced the subsequent expression of GATA3. Experiments using HDAC inhibitors and siRNAs showed that HDAC3 suppressed GATA3 expression. The recruitment of HDAC3 to the Gata3 promoter was decreased by PU.1 knockdown. LPS-induced IL-13 expression was dramatically reduced in BMDCs generated from mice lacking the conserved GATA3 response element, termed CGRE, which is an essential site for the binding of GATA3 on the Il-13 promoter. The degree of H3K4me3 at CGRE was significantly increased in PU.1 siRNA-transfected stimulated DCs. Our results indicate that PU.1 plays pivotal roles in DC development and function, serving not only as a transcriptional

  7. The 6th Meeting of the Global Alliance to Eliminate Lymphatic Filariasis: A half-time review of lymphatic filariasis elimination and its integration with the control of other neglected tropical diseases

    PubMed Central

    2010-01-01

    The 6th Meeting of the Global Alliance to Eliminate Lymphatic Filariasis (GAELF6) was held 1-3 June, 2010 in Seoul, Korea, with 150 participants from 38 countries. The year 2010 marks the midpoint between the first GAELF meeting, in 2000, and the World Health Organization (WHO) 2020 goal of global elimination of lymphatic filariasis (LF) as a public health problem. The theme of the meeting, "Half-time in LF Elimination: Teaming Up with Neglected Tropical Diseases (NTDs)," reflected significant integration of LF elimination programmes into a comprehensive initiative to control NTDs. Presentations on LF epidemiology, treatment, research, and programmes highlighted both accomplishments and remaining challenges. The WHO strategy to interrupt LF transmission is based on annual mass drug administration (MDA) using two-drug combinations. After mapping the geographic distribution of LF, MDA is implemented for ≥ 5 years, followed by a period of post-MDA surveillance, and, ultimately, verification of LF elimination. Morbidity management further reduces disease burden. Of 81 countries considered LF-endemic in 2000, 52 (64.2%) have begun MDA; 10 (12.3%) others with low-level transmission are unlikely to require MDA. In 2008, ~695 million people were offered treatment (51.7% of the at-risk population); ~496 million participated. Approximately 22 million people have been protected from LF infection and disease, with savings of ~US $24.2 billion. Morbidity management programmes have been implemented in 27 (33.3%) countries. Significant challenges to LF elimination remain. These include: initiating MDA in the remaining 19 countries that require it; achieving full geographic coverage in countries where MDA has started; finding alternative strategies to address the problem of Loa loa co-endemicity in Central Africa; developing strategies to treat urban populations; initiating and sustaining MDA in settings of armed conflict; developing refined guidelines and procedures for

  8. Patenting biotechnologies: the European Union Directive 98/44/EC of the European parliament and of the council of 6th July 1998 on the legal protection of biotechnological inventions.

    PubMed

    Morelli Gradi, G

    1999-01-01

    Before the Directive 98/44/EC of the European Parliament and the Council of 6th July 1998, notwithstanding some decisions of the European Patent Office (still presently under opposition) and some patents already granted by the Italian Patent Office, the existing legal framework did not allow the patentability of living organisms in the European Community countries. The Directive has dramatically changed the perspectives. It ensures free circulation of patented biotechnological products harmonising the national legal system of each Member State, guaranteeing compliance with the European Patent Convention signed in Munich on 5th October 1973, the Trade-Related Aspects of Intellectual Property Rights agreement of 15th April 1994 and the Rio de Janeiro Convention on Biological Diversity of 5th June 1992. The legal basis of the Directive and the fundamental principles of protection are that discoveries as such are not considered patentable. Plant and animal varieties as such, as well as essentially biological procedures for the production of plants and animals are excluded from protection by patent. On the contrary, the new field of patentability covers plants and parts of animals with new introduced genetic characters. Methods of surgical and therapeutic treatment and diagnostic methods applied to animal bodies are not considered inventions suitable for industrial applications and excluded from protection by patents. Biological materials and material isolated from its natural environment and isolated elements of the human body with technical processes may be patented. Excluded from patentability are inventions that are contrary to law and order or public morality as well as processes for human cloning for reproductive purposes and for modifying the germ-line genetic identity of human beings, as well as the use of human embryos. The processes for modifying the genetic identity of animals without any substantial medical benefit for man (with the exception of studying new

  9. Analytical method for the determination of Np and Pu in sea water by AMS with respect to the Fukushima accident

    NASA Astrophysics Data System (ADS)

    Hain, K.; Faestermann, T.; Famulok, N.; Fimiani, L.; Gómez-Guzmán, J. M.; Korschinek, G.; Kortmann, F.; Lierse v. Gostomski, Ch.; Ludwig, P.; Shinonaga, T.

    2015-10-01

    A chemical separation procedure for plutonium (Pu) and neptunium (Np) was developed using extraction chromatography, mass spectrometry and radiometric analysis to determine their concentrations and isotopic ratios in sea water. 241Am, which causes isobaric background to 241Pu in mass spectrometric measurements, was successfully separated from the Pu fraction by this method. Water samples which were spiked with 242Pu and 237Np or 239Np, respectively, were used for chemical yield determination. The chemical yields of Pu and Np, which were determined by alpha and gamma spectrometry at the Radiochemie München (RCM), of more than 85% were obtained. The developed method was applied to analyze the concentration of Pu and Np in the certified reference material, IAEA-443, by Accelerator Mass Spectrometry (AMS) at the Maier-Leibnitz-Laboratory (MLL) to check the applicability of the method to sea water samples. The concentrations of 240Pu, 241Pu and 237Np obtained in this study are in agreement with the certified and literature values within the uncertainties. Due to strong isotopic interference of 239Pu with 238U, it was not possible to analyze the concentration of 239Pu. Some modifications of the chemical separation method to suppress the uranium (U) fraction are under consideration. This method can be used for the analysis of Pu and Np in Pacific Ocean water samples collected after the Fukushima accident.

  10. Regulation of early T-lineage gene expression and developmental progression by the progenitor cell transcription factor PU.1.

    PubMed

    Champhekar, Ameya; Damle, Sagar S; Freedman, George; Carotta, Sebastian; Nutt, Stephen L; Rothenberg, Ellen V

    2015-04-15

    The ETS family transcription factor PU.1 is essential for the development of several blood lineages, including T cells, but its function in intrathymic T-cell precursors has been poorly defined. In the thymus, high PU.1 expression persists through multiple cell divisions in early stages but then falls sharply during T-cell lineage commitment. PU.1 silencing is critical for T-cell commitment, but it has remained unknown how PU.1 activities could contribute positively to T-cell development. Here we employed conditional knockout and modified antagonist PU.1 constructs to perturb PU.1 function stage-specifically in early T cells. We show that PU.1 is needed for full proliferation, restricting access to some non-T fates, and controlling the timing of T-cell developmental progression such that removal or antagonism of endogenous PU.1 allows precocious access to T-cell differentiation. Dominant-negative effects reveal that this repression by PU.1 is mediated indirectly. Genome-wide transcriptome analysis identifies novel targets of PU.1 positive and negative regulation affecting progenitor cell signaling and cell biology and indicating distinct regulatory effects on different subsets of progenitor cell transcription factors. Thus, in addition to supporting early T-cell proliferation, PU.1 regulates the timing of activation of the core T-lineage developmental program.

  11. Regulation of early T-lineage gene expression and developmental progression by the progenitor cell transcription factor PU.1

    PubMed Central

    Champhekar, Ameya; Damle, Sagar S.; Freedman, George; Carotta, Sebastian; Nutt, Stephen L.

    2015-01-01

    The ETS family transcription factor PU.1 is essential for the development of several blood lineages, including T cells, but its function in intrathymic T-cell precursors has been poorly defined. In the thymus, high PU.1 expression persists through multiple cell divisions in early stages but then falls sharply during T-cell lineage commitment. PU.1 silencing is critical for T-cell commitment, but it has remained unknown how PU.1 activities could contribute positively to T-cell development. Here we employed conditional knockout and modified antagonist PU.1 constructs to perturb PU.1 function stage-specifically in early T cells. We show that PU.1 is needed for full proliferation, restricting access to some non-T fates, and controlling the timing of T-cell developmental progression such that removal or antagonism of endogenous PU.1 allows precocious access to T-cell differentiation. Dominant-negative effects reveal that this repression by PU.1 is mediated indirectly. Genome-wide transcriptome analysis identifies novel targets of PU.1 positive and negative regulation affecting progenitor cell signaling and cell biology and indicating distinct regulatory effects on different subsets of progenitor cell transcription factors. Thus, in addition to supporting early T-cell proliferation, PU.1 regulates the timing of activation of the core T-lineage developmental program. PMID:25846797

  12. RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY

    SciTech Connect

    Maxwell, S.; Jones, V.; Culligan, B.; Nichols, S.; Noyes, G.

    2010-06-23

    A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4 to 6 hours, and can also be used for emergency response. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu, {sup 238}Pu, and {sup 239}Pu were measured by alpha spectrometry.

  13. ZPR-6 assembly 7 high {sup 240} PU core : a cylindrical assemby with mixed (PU, U)-oxide fuel and a central high {sup 240} PU zone.

    SciTech Connect

    Lell, R. M.; Schaefer, R. W.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; Nuclear Engineering Division; Inst. of Physics and Power Engineering

    2007-10-01

    Over a period of 30 years more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited to form the basis for criticality safety benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. The term 'benchmark' in a ZPR program connotes a particularly simple loading aimed at gaining basic reactor physics insight, as opposed to studying a reactor design. In fact, the ZPR-6/7 Benchmark Assembly (Reference 1) had a very simple core unit cell assembled from plates of depleted uranium, sodium, iron oxide, U3O8, and plutonium. The ZPR-6/7 core cell-average composition is typical of the interior region of liquid-metal fast breeder reactors (LMFBRs) of the era. It was one part of the Demonstration Reactor Benchmark Program,a which provided integral experiments characterizing the important features of demonstration

  14. Synthesis and structures of plutonyl nitrate complexes: is plutonium heptavalent in PuO3(NO3)2(-) ?

    PubMed

    Maurice, Rémi; Renault, Eric; Gong, Yu; Rutkowski, Philip X; Gibson, John K

    2015-03-01

    Gas-phase plutonium nitrate anion complexes were produced by electrospray ionization (ESI) of a plutonium nitrate solution. The ESI mass spectrum included species with all four of the common oxidation states of plutonium: Pu(III), Pu(IV), Pu(V), and Pu(VI). Plutonium nitrate complexes were isolated in a quadrupole ion trap and subjected to collision-induced dissociation (CID). CID of complexes of the general formula PuOx(NO3)y(-) resulted in the elimination of NO2 to produce PuOx+1(NO3)y-1(-), which in most cases corresponds to an increase in the oxidation state of plutonium. Plutonyl species, Pu(V)O2(NO3)2(-) and Pu(VI)O2(NO3)3(-), were produced from Pu(III)(NO3)4(-) and Pu(IV)(NO3)5(-), respectively, by the elimination of two NO2 molecules. CID of Pu(VI)O2(NO3)3(-) resulted in NO2 elimination to yield PuO3(NO3)2(-), in which the oxidation state of plutonium could be VII, a known oxidation state in condensed phase but not yet in the gas phase. Density functional theory confirmed the nature of Pu(V)O2(NO3)2(-) and Pu(VI)O2(NO3)3(-) as plutonyl(V/VI) cores coordinated by bidentate equatorial nitrate ligands. The computed structure of PuO3(NO3)2(-) is essentially a plutonyl(VI) core, Pu(VI)O2(2+), coordinated in the equatorial plane by two nitrate ligands and one radical oxygen atom. The computations indicate that in the ground spin-orbit free state of PuO3(NO3)2(-), the unpaired electron of the oxygen atom is antiferromagnetically coupled to the spin-triplet state of the plutonyl core. The results indicate that Pu(VII) is not a readily accessible oxidation state in the gas phase, despite that it is stable in solution and solids, but rather that a Pu(VI)-O· bonding configuration is favored, in which an oxygen radical is involved.

  15. Bacterial Pu(V) reduction in the absence and presence of Fe(III)-NTA: modeling and experimental approach

    SciTech Connect

    Deo, Randhir P; Rittmann, Bruce E; Reed, Donald T

    2013-01-10

    Plutonium (Pu), a key contaminant at sites associated with the manufacture of nuclear weapons and with nuclear-energy wastes, can be precipitated to 'immobilized' plutonium phases in systems that promote bioreduction. Ferric iron (Fe3+) is often present in contaminated sites, and its bioreduction to ferrous iron (Fe2+) may be involved in the reduction of Pu to forms that precipitate. Alternately, Pu can be reduced directly by the bacteria. Besides Fe, contaminated sites often contain strong complexing ligands, such as nitrilotriacetic acid (NTA). We used biogeochemical modeling to interpret the experimental fate of Pu in the absence and presence of ferric iron (Fe3+) and NTA under anaerobic conditions. In all cases, Shewanella alga BrY (S. alga) reduced Pu(V)(PuO2+) to Pu(III), and experimental evidence indicates that Pu(III) precipitated as PuPO4(am). In the absence of Fe3+ and NTA, reduction of PuO2+ was directly biotic, but modeling simulations support that PuO2+ reduction in the presence of Fe3+ and NTA was due to an abiotic stepwise reduction of PuO2+ to Pu4+, followed by reduction of Pu4+ to Pu3+, both through biogenically produced Fe2+. This means that PuO2+ reduction was slowed by first having Fe3+ reduced to Fe2+. Modeling results also show that the degree of PuPO4(am) precipitation depends on the NTA concentration. While precipitation out-competes complexation when NTA is present at the same or lower concentration than Pu, excess NTA can prevent precipitation of PuPO4(am).

  16. Spi-1/PU.1 transgenic mice develop multistep erythroleukemias.

    PubMed Central

    Moreau-Gachelin, F; Wendling, F; Molina, T; Denis, N; Titeux, M; Grimber, G; Briand, P; Vainchenker, W; Tavitian, A

    1996-01-01

    Insertional mutagenesis of the spi-1 gene is associated with the emergence of malignant proerythroblasts during Friend virus-induced acute erythroleukemia. To determine the role of spi-1/PU.1 in the genesis of leukemia, we generated spi-1 transgenic mice. In one founder line the transgene was overexpressed as an unexpected-size transcript in various mouse tissues. Homozygous transgenic animals gave rise to live-born offspring, but 50% of the animals developed a multistep erythroleukemia within 1.5 to 6 months of birth whereas the remainder survived without evidence of disease. At the onset of the disease, mice became severely anemic. Their hematopoietic tissues were massively invaded with nontumorigenic proerythroblasts that express a high level of Spi-1 protein. These transgenic proerythroblasts are partially blocked in differentiation and strictly dependent on erythropoietin for their proliferation both in vivo and in vitro. A complete but transient regression of the disease was observed after erythrocyte transfusion, suggesting that the constitutive expression of spi-1 is related to the block of the differentiation of erythroid precursors. At relapse, erythropoietin-independent malignant proerythroblasts arose. Growth factor autonomy could be partially explained by the autocrine secretion of erythropoietin; however, other genetic events appear to be necessary to confer the full malignant phenotype. These results reveal that overexpression of spi-1 is essential for malignant erythropoiesis and does not alter other hematopoietic lineages. PMID:8628313

  17. Prompt Fission Neutron Emission in Resonance Fission of 239Pu

    SciTech Connect

    Hambsch, Franz-Josef; Oberstedt, Stephan; Varapai, Natallia; Serot, Olivier

    2005-05-24

    The prompt neutron emission probability from neutron-induced fission in the resonance region is being investigated at the time-of-flight facility GELINA of the IRMM. A double Frisch-gridded ionization chamber is used as a fission-fragment detector. For the data acquisition of both the fission-fragment signals as well as the neutron detector signals the fast digitization technique has been applied. For the neutron detection, large-volume liquid scintillation detectors from the DEMON collaboration are used. A specialized data analysis program taking advantage of the digital filtering technique has been developed to treat the acquired data.Neutron multiplicity investigations for actinides, especially in resonance neutron-induced fission, are rather scarce. They are, however, important for reactor control and safety issues as well as for understanding the basic physics of the fission process. Fission yield measurements on both 235U and 239Pu without prompt neutron emission coincidence have shown that fluctuation of the fission-fragment mass distribution exists from resonance to resonance, larger in the case of 235U. To possibly explain these observations, the question now is whether the prompt neutron multiplicity shows similar fluctuations with resonance energy.

  18. Osteosarcomas among beagles exposed to /sup 239/Pu

    SciTech Connect

    Whittemore, A.S.; McMillan, A.

    1982-04-01

    A Weibull distribution was fit to the osteosarcoma death times of beagles given single intravenous injections of /sup 239/Pu. For injected doses in the range 0-1..mu..Ci/kg the osteosarcoma incidence rate h(t) at t days after injection can be fit by a quadratic function of injected dose d: h(t) = 2.61 X 10/sup -18/ d/sup 2/t/sup 4.91/. The best-fitting linear function was rejected by the data (P < 0.001). A different formula for h(t), derived from a multistage theory for osteosarcoma induction, was also fit to these data. For this purpose microdosimetry calculations were used to estimate the dose to the cells at risk in the endosteal layer (endosteal dose). According to the best fit, h(t) is a quadratic function of endosteal dose at low doses. A linear dose-response relationship was again rejected. The absence of a linear component at low doses might be explained by the fact that 108 of the 185 animals injected at the lowest doses (<0.02 ..mu..Ci/kg) were still alive at the time these data were collected.

  19. The influence of defects on magnetic properties of fcc-Pu

    SciTech Connect

    Shorikov, A. O.; Anisimov, V. I.; Korotin, M. A.; Dremov, V. V. Sapozhnikov, Ph. A.

    2013-10-15

    The influence of vacancies and interstitial atoms on magnetism in Pu is considered in the framework of the density functional theory. The crystal structure relaxation arising due to various types of defects is calculated using the molecular dynamics method with a modified embedded atom model. The local density approximation with explicit inclusion of Coulomb and spin-orbit interactions is applied in matrix invariant form to describe correlation effects in Pu with these types of defects. The calculations show that both vacancies and interstitials give rise to local moments in the f-shell of Pu in good agreement with experimental data for aged Pu. Magnetism appears due to the destruction of a delicate balance between spin-orbit and exchange interactions.

  20. Characterization and property evaluation of U-15 wt%Pu alloy for fast reactor

    NASA Astrophysics Data System (ADS)

    Kaity, Santu; Banerjee, Joydipta; Ravi, K.; Keswani, R.; Kutty, T. R. G.; Kumar, Arun; Prasad, G. J.

    2013-02-01

    The characterization and high temperature behaviour of U-15 wt%Pu alloy has been investigated in this study for the first time. U-15 wt%Pu alloy sample for this study was prepared by following melting and casting route. Microstructural characterization of the alloy was carried out by XRD and optical microscopy. The thermophysical properties like phase transition temperatures, coefficient of thermal expansion and hot hardness of the above alloy were determined. Eutectic temperature between T91 and U-15 wt%Pu was established. Apart from that, the fuel-cladding chemical compatibility of U-15 wt%Pu alloy with T91 grade steel was studied by diffusion couple experiment.

  1. Surprising Coordination Geometry Differences in Ce(IV)- and Pu(IV)-Maltol Complexes

    SciTech Connect

    Lawrence Berkeley National Laboratory; Raymond, Kenneth; Szigethy, Geza; Xu, Jide; Gorden, Anne E.V.; Teat, Simon J.; Shuh, David K.; Raymond, Kenneth N.

    2008-02-12

    As part of a study to characterize the detailed coordination behavior of Pu(IV), single crystal X-ray diffraction structures have been determined for Pu(IV) and Ce(IV) complexes with the naturally-occurring ligand maltol (3-hydroxy-2-methyl-pyran-4-one) and its derivative bromomaltol (5-bromo-3-hydroxy-2-methyl-pyran-4-one). Although Ce(IV) is generally accepted as a structural analog for Pu(IV), and the maltol complexes of these two metals are isostructural, the corresponding bromomaltol complexes are strikingly different with respect to ligand orientation about the metal ion: All complexes exhibit trigonal dodecahedral coordination geometry but the Ce(IV)-bromomaltol complex displays an uncommon ligand arrangement not mirrored in the Pu(IV) complex, although the two metal species are generally accepted to be structural analogs.

  2. [Analysis of rare earth elements in pu'er tea of Yunnan by ICP-AES].

    PubMed

    Ning, Peng-bo; Gong, Chun-mei; Zhang, Yan-ming; Guo, Kang-kang

    2010-10-01

    The 150 samples of pu'er tea collected from the main producing area of Yunnan were detected by ICP-AES method, to investigate the current safety status of pu'er tea rare earth elements. The rare earth elements contents were found to be in the range 0.26-4.07 mg x kg(-1) in all detected samples, with the 43.0% samples exceeding the maximum levels of contaminants of 2 mg x kg(-1) set by GB 2762-2005 "Maximum levels of contaminants in foods". There was a significant difference between ripened tea rare earth elements and raw tea's from the same sources, which affected some ripened tea quality at last. There was a significant difference among the rare earth elements contents of the pu'er tea main producing areas, and the condition of pu'er tea quality and safety controlling was not optimistic at individual producing areas.

  3. Characterization of high-fired PuO/sub 2/ as a certified reference material

    SciTech Connect

    Legeled, M.A.; Cacic, C.G.; Crawford, D.W.; Spaletto, M.I.

    1984-07-01

    The New Brunswick Laboratory (NBL), U.S. Department of Energy, has certified a plutonium dioxide reference material, CRM 122, for plutonium assay and isotopic composition. The PuO/sub 2/ standard, one of several certified Pu reference materials currently being developed at NBL for use in instrumentation calibration and measurement control for safeguards, establishes traceability to the national measurement base. This plutonium reference material in the oxide form provides more directly demonstrable traceability than metal because it undergoes the same chemical treatment for dissolution as PuO/sub 2/ fuel materials. Various tests for achieving a constant weight and for dissolving CRM 122 high-fired PuO/sub 2/ were conducted. Results of these tests as well as the certification data generated by controlled-potential coulometry for plutonium assay and by thermal ionization mass spectrometry for isotopic composition will also be presented and discussed.

  4. Improved electrospinning processing of PU/PEDOT:PSS for electronic textile applications

    NASA Astrophysics Data System (ADS)

    Evke, Erin; Clippinger, Aaron; Spackman, Clayson; Samuel, Johnson; Ozisik, Rahmi

    Poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate), PEDOT:PSS, is an electrically conductive polymer used in electronic textile (e-textile) applications, such as eletrochromic textiles, strain sensors, and resistive heaters. In the current study, PEDOT:PSS is blended with varying concentrations of polyurethane (PU) to investigate the flexibility of PU/PEDOT:PSS fibers that are produced via a modified electrospinning process where the jet is collected close to the tip of the needle, thereby, enabling the collection of straight fibers by a rotating spool. The electrical conductivity and mechanical properties of PU/PEDOT:PSS fibers are characterized to understand the effect of PU concentration and the processing parameters. This material is based upon work supported by the National Science Foundation under Grant No. CMMI-1538730.

  5. New phenylpropanoid-substituted flavan-3-ols from Pu-er ripe tea.

    PubMed

    Tao, Mu-Ke; Xu, Min; Zhu, Hong-Tao; Cheng, Rong-Rong; Wang, Dong; Yang, Chong-Ren; Zhang, Ying-Jun

    2014-08-01

    Pu-er ripe tea is a special microbial post-fermented tea made from Pu-er raw tea, a kind of green tea produced from the leaves of Camellia sinensis var. assamica. It is one of the most consumed teas in the past two decades in China, due to its special flavor, taste, and beneficial effects. This work aimed to obtain diverse catechin structures from Pu-er ripe tea, which led to the isolation of four new phenylpropanoid-substituted flavan-3-ols, puerins C-F (1-4), together with four known flavan-3-ols, (+)-catechin (5), (-)-epicatechin (6), (+/-)-gallocatechin (7), and (-)-epigallocatechin (8). Their structures were elucidated on the basis of detailed spectroscopic analysis, including 1D and 2D NMR, mass and CD spectra. Compounds 1-4, which could be formed in the post-fermentative process of Pu-er tea, were isolated for the first time from tea and Theaceae plant.

  6. /sup 238/Pu fuel form processes. Quarterly report, October-December 1980

    SciTech Connect

    Not Available

    1981-08-01

    Goals of the Savannah River Laboratory (SRL) program include providing technical support for the production of /sup 238/PuO/sub 2/ fuel forms in the Savannah River Plant's (SRP) Plutonium Fuel Form (PuFF) Facility. Progress is reported including studies on the impact response of SRP MHW /sup 238/PuO/sub 2/ fuel spheres. The iridium containment shell of an encapsulated SRP fuel sphere, Multi-hundred Watt Fuel Test (MHFT) 65 split open during a Safety Verification Impact Test (SVT), and about 2 g of /sup 238/PuO/sub 2/ was released. (Typical oxide releases in previous tests were 1 to 10 mg). The cause of the impact failure was investigated. Also, the feasibility of using a direct fabrication process to produce full-scale GPHS fuel pellets has been demonstrated. (WHK)

  7. Role of PU.1 in MHC Class II Expression via CIITA Transcription in Plasmacytoid Dendritic Cells.

    PubMed

    Miura, Ryosuke; Kasakura, Kazumi; Nakano, Nobuhiro; Hara, Mutsuko; Maeda, Keiko; Okumura, Ko; Ogawa, Hideoki; Yashiro, Takuya; Nishiyama, Chiharu

    2016-01-01

    The cofactor CIITA is a master regulator of MHC class II expression and several transcription factors regulating the cell type-specific expression of CIITA have been identified. Although the MHC class II expression in plasmacytoid dendritic cells (pDCs) is also mediated by CIITA, the transcription factors involved in the CIITA expression in pDCs are largely unknown. In the present study, we analyzed the role of a hematopoietic lineage-specific transcription factor, PU.1, in CIITA transcription in pDCs. The introduction of PU.1 siRNA into mouse pDCs and a human pDC cell line, CAL-1, reduced the mRNA levels of MHC class II and CIITA. When the binding of PU.1 to the 3rd promoter of CIITA (pIII) in CAL-1 and mouse pDCs was analyzed by a chromatin immunoprecipitation assay, a significant amount of PU.1 binding to the pIII was detected, which was definitely decreased in PU.1 siRNA-transfected cells. Reporter assays showed that PU.1 knockdown reduced the pIII promoter activity and that three Ets-motifs in the human pIII promoter were candidates of cis-enhancing elements. By electrophoretic mobility shift assays, it was confirmed that two Ets-motifs, GGAA (-181/-178) and AGAA (-114/-111), among three candidates, were directly bound with PU.1. When mouse pDCs and CAL-1 cells were stimulated by GM-CSF, mRNA levels of PU.1, pIII-driven CIITA, total CIITA, MHC class II, and the amount of PU.1 binding to pIII were significantly increased. The GM-CSF-mediated up-regulation of these mRNAs was canceled in PU.1 siRNA-introduced cells. Taking these results together, we conclude that PU.1 transactivates the pIII through direct binding to Ets-motifs in the promoter in pDCs.

  8. Chemical separation and ICP-AES determination of 22 metallic elements in U and Pu matrices using cyanex-923 extractant and studies on stripping of U and Pu.

    PubMed

    Argekar, A A; Kulkarni, M J; Mathur, J N; Page, A G

    2002-03-11

    Comprehensive studies have been carried out on the extraction behavior of uranium and plutonium matrices using cyanex-923 extractant. The near total extraction of U/Pu and quantitative separation of 22 metallic elements at trace levels has been established using inductively coupled plasma-atomic emission spectrometry (ICP-AES). The studies carried out on back extraction of U/Pu from organic phase have established the near total recovery of these matrices into the aqueous phase using 1 M Na(2)CO(3) and saturated oxalic acid, respectively.

  9. Pu Sorption, Desorption and Intrinsic Colloid Stability under Granitic Chemical Conditions

    SciTech Connect

    Zhao, Pihong; Zavarin, Mavrik; Dai, Zurong; Kersting, Annie B.

    2014-09-04

    This progress report (M4FT-14LL0807031) describes research conducted at LLNL as part of the Crystalline Repository effort within the UFD program. Part I describes the dissolution kinetics of intrinsic Pu colloids synthesized in an alkaline solution. Part II describes the morphology and dissolution characteristics of various forms of Pu oxides prepared over a range of solution and temperature conditions. Proposed FY15 activities are identified.

  10. Mass transport properties of Pu/DT mixtures from orbital free molecular dynamics simulations

    SciTech Connect

    Kress, Joel David; Ticknor, Christopher; Collins, Lee A.

    2015-09-16

    Mass transport properties (shear viscosity and diffusion coefficients) for Pu/DT mixtures were calculated with Orbital Free Molecular Dynamics (OFMD). The results were fitted to simple functions of mass density (for ρ=10.4 to 62.4 g/cm3) and temperature (for T=100 up to 3,000 eV) for Pu/DT mixtures consisting of 100/0, 25/75, 50/50, and 75/25 by number.

  11. Transcriptional Factor PU.1 Regulates Decidual C1q Expression in Early Pregnancy in Human.

    PubMed

    Madhukaran, Shanmuga Priyaa; Kishore, Uday; Jamil, Kaiser; Teo, Boon Heng Dennis; Choolani, Mahesh; Lu, Jinhua

    2015-01-01

    C1q is the first recognition subcomponent of the complement classical pathway, which in addition to being synthesized in the liver, is also expressed by macrophages and dendritic cells (DCs). Trophoblast invasion during early placentation results in accumulation of debris that triggers the complement system. Hence, both early and late components of the classical pathway are widely distributed in the placenta and decidua. In addition, C1q has recently been shown to significantly contribute to feto-maternal tolerance, trophoblast migration, and spiral artery remodeling, although the exact mechanism remains unknown. Pregnancy in mice, genetically deficient in C1q, mirrors symptoms similar to that of human preeclampsia. Thus, regulated complement activation has been proposed as an essential requirement for normal successful pregnancy. Little is known about the molecular pathways that regulate C1q expression in pregnancy. PU.1, an Ets-family transcription factor, is required for the development of hematopoietic myeloid lineage immune cells, and its expression is tissue-specific. Recently, PU.1 has been shown to regulate C1q gene expression in DCs and macrophages. Here, we have examined if PU.1 transcription factor regulates decidual C1q expression. We used immune-histochemical analysis, PCR, and immunostaining to localize and study the gene expression of PU.1 transcription factor in early human decidua. PU.1 was highly expressed at gene and protein level in early human decidual cells including trophoblast and stromal cells. Surprisingly, nuclear as well as cytoplasmic PU.1 expression was observed. Decidual cells with predominantly nuclear PU.1 expression had higher C1q expression. It is likely that nuclear and cytoplasmic PU.1 localization has a role to play in early pregnancy via regulating C1q expression in the decidua during implantation.

  12. Comparative Photoemission Study of Actinide (Am, Pu, Np and U) Metals, Nitrides, and Hydrides

    SciTech Connect

    Gouder, Thomas; Seibert, Alice; Rebizant, Jean; Huber, Frank; Havela, Ladislav

    2007-07-01

    Core-level and valence-band spectra of Pu and the other early actinide compounds show remarkable systematics, which can be understood in the framework of final state screening. We compare the early actinide (U, Np, Pu and Am) metals, nitrides and hydrides and a few other specific compounds (PuSe, PuS, PuCx, PuSix) prepared as thin films by sputter deposition. In choosing these systems, we combine inherent 5f band narrowing, due to 5f orbital contraction throughout the actinide series, with variations of the chemical environment in the compounds. Goal of this work was to learn more on the electronic structure of the early actinide systems and to achieve the correct interpretation of their photoemission spectra. The highly correlated nature of the 5f states in systems, which are on the verge to localization, makes this a challenging task, because of the peculiar interplay between ground state DOS and final-state effects. Their influence can be estimated by doing systematic studies on systems with different (5f) bandwidths. We conclude on the basis of such systematic experiments that final-state effects due to strong e-e correlations in narrow 5f-band systems lead to multiplet like structures, analogous to those observed in the case of systems with localized electron states. Such observations in essentially band-like 5f-systems was first surprising, but the astonishing similarity of photoemission spectra of very different chemical systems (e.g. PuSe, Pu{sub 2}C{sub 3}..) points to a common origin, relating them to atomic features rather than material dependent density of states (DOS) features. (authors)

  13. Structural Investigation of (U0.7Pu0.3)O2-x Mixed Oxides.

    PubMed

    Vigier, Jean-François; Martin, Philippe M; Martel, Laura; Prieur, Damien; Scheinost, Andreas C; Somers, Joseph

    2015-06-01

    Uranium-plutonium mixed oxide containing 30% of plutonium is a candidate fuel for several fast neutron and accelerator driven reactor systems. In this work, a detailed structural investigation on sol-gel synthesized stoichiometric U0.7Pu0.3O2.00 and substoichiometric U0.7Pu0.3O2-x, using X-ray diffraction (XRD), oxygen 17 magic angle spinning nuclear magnetic resonance ((17)O MAS NMR) and X-ray absorption spectroscopy is described. As observed by XRD, the stoichiometric U0.7Pu0.3O2.00 is monophasic with a lattice parameter in good agreement with Vegard's law, while the substoichiometric U0.7Pu0.3O2-x material is biphasic. Solid solution ideality in terms of a random distribution of metal atoms is proven for U0.7Pu0.3O2.00 with (17)O MAS NMR. X-ray absorption near-edge structure (XANES) spectroscopy shows the presence of plutonium(III) in U0.7Pu0.3O2-x. Extended X-ray absorption fine-structure (EXAFS) spectroscopy indicates a similar local structure around both cations, and comparison with XRD indicates a close similarity between uranium and plutonium local structures and the long-range ordering. PMID:25984750

  14. Application of a canine {sup 238}Pu biokinetics/dosimetry model to human bioassay data

    SciTech Connect

    Hickman, A.W. |; Griffith, W.C.; Guilmette, R.A.

    1995-03-01

    Associated with the use of {sup 238}Pu in thermoelectric power sources for space probes is the potential for human exposure, primarily by inhalation and most likely as {sup 238}PuO{sub 2}. Several models have been developed for assessing the level of intake and predicting the resulting radiation dose following human exposure to {sup 239}Pu. However, there are indications that existing models do not adequately describe the disposition and dosimetry of {sup 239}Pu following human exposure. In this study, a canine model that accounts for these differences has been adapted for use with human excretion data. The model is based on existing knowledge about organ retention of plutonium. An analysis of the sensitivity of the model to changes in aerosol-associated properties indicated that predictions of urinary excretion are most sensitive to changes in particle solubility and diameter and in the ratio of fragment:particle surface area. Application of the model to urinary excretion data from seven workers exposed to a {sup 238}Pu ceramic aerosol gave estimated intakes of 390-8,200 Bq and associated initial pulmonary burdens of 80-1,700 Bq. The resulting 50-y dose commitments to critical organs per Bq of {sup 238}Pu intake were estimated to be 0.5 mSv for the thoracic region, 0.2 mSv for the liver, and 1 mSv for the bone surfaces. 29 refs., 8 figs., 7 tabs.

  15. Absolute measurement of the 242Pu neutron-capture cross section

    DOE PAGES

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; et al

    2016-04-21

    Here, the absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. The first direct measurement of the 242Pu(n,γ) cross section was made over the incident neutron energy range from thermal to ≈ 6 keV, and the absolute scale of the (n,γ) cross section was set according to the known 239Pu(n,f) resonance at En,R = 7.83 eV. This was accomplished by adding a small quantity of 239Pu to the 242Pu sample. The relative scale of the crossmore » section, with a range of four orders of magnitude, was determined for incident neutron energies from thermal to ≈ 40 keV. Our data, in general, are in agreement with previous measurements and those reported in ENDF/B-VII.1; the 242Pu(n,γ) cross section at the En,R = 2.68 eV resonance is within 2.4% of the evaluated value. However, discrepancies exist at higher energies; our data are ≈30% lower than the evaluated data at En ≈ 1 keV and are approximately 2σ away from the previous measurement at En ≈ 20 keV.« less

  16. Measurement of Neutron Induced and Spontaneous Fission in Pu-242 at DANCE

    NASA Astrophysics Data System (ADS)

    Chyzh, Andrii; Wu, C. Y.; Henderson, R.; Couture, A.; Lee, H. Y.; Ullmann, J.; O'Donnell, J. M.; Jandel, M.; Haight, R. C.; Bredeweg, T. A.; Dance Collaboration

    2013-10-01

    Neutron capture and fission reactions are important in nuclear engineering and physics. DANCE (Detector for Advanced Neutron Capture Measurement, LANL) combined with PPAC (avalanche technique based fission tagging detector, LLNL) were used to study neutron induced and spontaneous fission in 242Pu. 2 measurements were performed in 2013. The first experiment was done without the incident neutron beam with the fission tagging ability to study γ-rays emitted in the spontaneous fission of 242Pu. The second one - with the neutron beam to measure both the neutron capture and fission reactions. This is the first direct measurement of prompt fission γ-rays in 242Pu. The γ-ray multiplicity, γ-ray energy, and total energy of γ-rays per fission in 242Pu will be presented. These distributions of the 242Pu spontaneous fission will be compared to those in the 241Pu neutron induced fission. This work was performed under the auspices of the US Department of Energy by Los Alamos National Laboratory under Contract DE-AC52-06NA25396 and Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  17. Absolute measurement of the 242Pu neutron-capture cross section

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Dance Collaboration

    2016-04-01

    The absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. The first direct measurement of the 242Pu(n ,γ ) cross section was made over the incident neutron energy range from thermal to ≈6 keV, and the absolute scale of the (n ,γ ) cross section was set according to the known 239Pu(n ,f ) resonance at En ,R=7.83 eV. This was accomplished by adding a small quantity of 239Pu to the 242Pu sample. The relative scale of the cross section, with a range of four orders of magnitude, was determined for incident neutron energies from thermal to ≈40 keV. Our data, in general, are in agreement with previous measurements and those reported in ENDF/B-VII.1; the 242Pu(n ,γ ) cross section at the En ,R=2.68 eV resonance is within 2.4 % of the evaluated value. However, discrepancies exist at higher energies; our data are ≈30 % lower than the evaluated data at En≈1 keV and are approximately 2 σ away from the previous measurement at En≈20 keV.

  18. Structural Investigation of (U0.7Pu0.3)O2-x Mixed Oxides.

    PubMed

    Vigier, Jean-François; Martin, Philippe M; Martel, Laura; Prieur, Damien; Scheinost, Andreas C; Somers, Joseph

    2015-06-01

    Uranium-plutonium mixed oxide containing 30% of plutonium is a candidate fuel for several fast neutron and accelerator driven reactor systems. In this work, a detailed structural investigation on sol-gel synthesized stoichiometric U0.7Pu0.3O2.00 and substoichiometric U0.7Pu0.3O2-x, using X-ray diffraction (XRD), oxygen 17 magic angle spinning nuclear magnetic resonance ((17)O MAS NMR) and X-ray absorption spectroscopy is described. As observed by XRD, the stoichiometric U0.7Pu0.3O2.00 is monophasic with a lattice parameter in good agreement with Vegard's law, while the substoichiometric U0.7Pu0.3O2-x material is biphasic. Solid solution ideality in terms of a random distribution of metal atoms is proven for U0.7Pu0.3O2.00 with (17)O MAS NMR. X-ray absorption near-edge structure (XANES) spectroscopy shows the presence of plutonium(III) in U0.7Pu0.3O2-x. Extended X-ray absorption fine-structure (EXAFS) spectroscopy indicates a similar local structure around both cations, and comparison with XRD indicates a close similarity between uranium and plutonium local structures and the long-range ordering.

  19. Thermophysical properties and oxygen transport in the (Ux,Pu1-x)O2 lattice

    NASA Astrophysics Data System (ADS)

    Cooper, M. W. D.; Murphy, S. T.; Rushton, M. J. D.; Grimes, R. W.

    2015-06-01

    Using molecular dynamics, the thermophysical properties of the (Ux,Pu1-x)O2 system have been investigated between 300 and 3200 K. The variation with temperature of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure, are explained in terms of defect formation and diffusivity on the oxygen sublattice. Vegard's Law is approximately observed for the thermal expansion of the solid solutions below 2000 K. Deviation from Vegard's Law above this temperature occurs due to the different superionic transition temperatures of the solid solutions (2200-2900 K). Similarly, a spike in the specific heat, associated with the superionic transition, occurs at lower temperatures in solid solutions that have a high Pu content. While oxygen diffusivity is higher in pure PuO2 than in pure UO2, lower oxygen defect enthalpies in (Ux,Pu1-x)O2 solid solutions cause higher oxygen mobility than would be expected by interpolation between the diffusivities of the end members. In comparison to UO2 and PuO2 there is considerable variety of oxygen vacancy and oxygen interstitial sites in solid solutions generating a wide range of property values. Trends in the defect enthalpies are discussed in terms of composition and the lattice parameter of (Ux,Pu1-x)O2. Comparison is made with previous work on (Ux,Th1-x)O2.

  20. PU/SS EUTECTIC ASSESSMENT IN 9975 PACKAGINGS IN A STORAGE FACILITY DURING EXTENDED FIRE

    SciTech Connect

    Gupta, N.

    2012-03-26

    In a radioactive material (RAM) packaging, the formation of eutectic at the Pu/SS (plutonium/stainless steel) interface is a serious concern and must be avoided to prevent of leakage of fissile material to the environment. The eutectic temperature for the Pu/SS is rather low (410 C) and could seriously impact the structural integrity of the containment vessel under accident conditions involving fire. The 9975 packaging is used for long term storage of Pu bearing materials in the DOE complex where the Pu comes in contact with the stainless steel containment vessel. Due to the serious consequences of the containment breach at the eutectic site, the Pu/SS interface temperature is kept well below the eutectic formation temperature of 410 C. This paper discusses the thermal models and the results for the extended fire conditions (1500 F for 86 minutes) that exist in a long term storage facility and concludes that the 9975 packaging Pu/SS interface temperature is well below the eutectic temperature.

  1. Conversion electron spectrometry of Pu isotopes with a silicon drift detector.

    PubMed

    Pommé, S; Paepen, J; Peräjärvi, K; Turunen, J; Pöllänen, R

    2016-03-01

    An electron spectrometry set-up was built at IRMM consisting of a vacuum chamber with a moveable source holder and windowless Peltier-cooled silicon drift detector (SDD). The SDD is well suited for measuring low-energy x rays and electrons emitted from thin radioactive sources with low self-absorption. The attainable energy resolution is better than 0.5keV for electrons of 30keV. It has been used to measure the conversion electron spectra of three plutonium isotopes, i.e. (238)Pu, (239)Pu, (240)Pu, as well as (241)Am (being a decay product of (241)Pu). The obtained mixed x-ray and electron spectra are compared with spectra obtained with a close-geometry set-up using another SDD in STUK and spectra measured with a Si(Li) detector at IRMM. The potential of conversion electron spectrometry for isotopic analysis of mixed plutonium samples is investigated. With respect to the (240)Pu/(239)Pu isotopic ratio, the conversion electron peaks of both isotopes are more clearly separated than their largely overlapping peaks in alpha spectra. PMID:26651177

  2. Application of a canine 238Pu biokinetics/dosimetry model to human bioassay data.

    PubMed

    Hickman, A W; Griffith, W C; Roessler, G S; Guilmette, R A

    1995-03-01

    Associated with the use of 238Pu in thermoelectric power sources for space probes is the potential for human exposure, primarily by inhalation and most likely as 238PuO2. Several models have been developed for assessing the level of intake and predicting the resulting radiation dose following human exposure to 239Pu. However, there are indications that existing models do not adequately describe the disposition and dosimetry of 238Pu following human exposure. In this study, a canine model that accounts for these differences has been adapted for use with human excretion data. The model is based on existing knowledge about organ retention of plutonium. An analysis of the sensitivity of the model to changes in aerosol-associated properties indicated that predictions of urinary excretion are most sensitive to changes in particle solubility and diameter and in the ratio of fragment:particle surface area. Application of the model to urinary excretion data from seven workers exposed to a 238Pu ceramic aerosol gave estimated intakes of 390-8,200 Bq and associated initial pulmonary burdens of 80-1,700 Bq. The resulting 50-y dose commitments to critical organs per Bq of 238Pu intake were estimated to be 0.5 mSv for the thoracic region, 0.2 mSv for the liver, and 1 mSv for the bone surfaces. PMID:7860307

  3. Conversion electron spectrometry of Pu isotopes with a silicon drift detector.

    PubMed

    Pommé, S; Paepen, J; Peräjärvi, K; Turunen, J; Pöllänen, R

    2016-03-01

    An electron spectrometry set-up was built at IRMM consisting of a vacuum chamber with a moveable source holder and windowless Peltier-cooled silicon drift detector (SDD). The SDD is well suited for measuring low-energy x rays and electrons emitted from thin radioactive sources with low self-absorption. The attainable energy resolution is better than 0.5keV for electrons of 30keV. It has been used to measure the conversion electron spectra of three plutonium isotopes, i.e. (238)Pu, (239)Pu, (240)Pu, as well as (241)Am (being a decay product of (241)Pu). The obtained mixed x-ray and electron spectra are compared with spectra obtained with a close-geometry set-up using another SDD in STUK and spectra measured with a Si(Li) detector at IRMM. The potential of conversion electron spectrometry for isotopic analysis of mixed plutonium samples is investigated. With respect to the (240)Pu/(239)Pu isotopic ratio, the conversion electron peaks of both isotopes are more clearly separated than their largely overlapping peaks in alpha spectra.

  4. DNA methylation-mediated silencing of PU.1 in leukemia cells resistant to cell differentiation.

    PubMed

    Fernández-Nestosa, María José; Monturus, Estefanía; Sánchez, Zunilda; Torres, Francisco S; Fernández, Agustín F; Fraga, Mario F; Hernández, Pablo; Schvartzman, Jorge B; Krimer, Dora B

    2013-01-01

    In mice, the proviral integration of the Friend Spleen Focus Forming Virus (SFFV) within the PU.1 locus of erythroid precursors results in the development of erythroleukemia. SFFV integrates several kilobases upstream of the PU.1 transcription initiation start site leading to the constitutive activation of the gene which in turn results in a block of erythroid differentiation. In this study we have mapped and sequenced the exact location of the retroviral integration site. We have shown that SFFV integrates downstream of a previously described upstream regulatory element (URE), precisely 2,976 bp downstream of the URE-distal element. We have also found that SFFV persists integrated within the same location in resistant cell lines that have lost their differentiation capacity and in which case PU.1 remains silent. We have examined the methylation status of PU.1 and found that in resistant cells the nearby CpG islands remained methylated in contrast to a non-methylated status of the parental cell lines. Treatment with 5-aza-2'-deoxycytidine caused resistant cells to differentiate yet only when combined with HMBA. Altogether these results strongly suggest that methylation plays a crucial role with regard to PU.1 silencing. However, although demethylation is required, it is not sufficient to overcome the differentiation impasse. We have also showed that activation blockage of the Epo/Epo-R pathway remains despite of the absence of PU.1.

  5. COMPUTER SIMULATIONS TO ADDRESS PU-FE EUTECTICISSUE IN 3013 STORAGE VESSEL

    SciTech Connect

    Gupta, N; Allen Smith, A

    2007-03-06

    On November 22, 2005, the Manager of the Plutonium Finishing Plant (PFP) in Richland, WA issued an Occurrence Report involving a potential Pu-Fe eutectic failure mechanism for the stainless steel (SS) 3013 cans containing plutonium (Pu) metal. Four additional reports addressed nuclear safety concerns about the integrity of stainless steel containers holding plutonium during fire scenarios. The reports expressed a belief that the probability and consequences of container failure due to the formation of a plutonium-iron eutectic alloy had been overlooked. Simplified thermal model to address the Pu-Fe eutectic concerns using axisymmetric model similar to the models used in the 9975 SARP were performed. The model uses Rocky Flats configuration with 2 stacked Pu buttons inside a 3013 assembly. The assembly has an outer can, an inner can, and a convenience can, all stainless steel. The boundary conditions are similar to the regulatory 30 minutes HAC fire analyses. Computer simulations of the HAC fire transients lasting 4 hours of burn time show that the interface between the primary containment vessel and the Pu metal in the 9975 package will not reach Pu-Fe eutectic temperature of 400 C.

  6. Colloid-Facilitated Transport of Plutonium, Pu(+V), in Saturated Alluvium

    NASA Astrophysics Data System (ADS)

    Abdel-Fattah, A. I.; Reimus, P. W.; Ware, S.; Haga, M. H.

    2004-12-01

    Natural groundwater colloids can facilitate the subsurface transport of strongly-sorbing radionuclides, such as plutonium (Pu). To evaluate this mechanism, packed-bed column experiments were conducted, comparing the simultaneous transport of dissolved plutonium (Pu-239) of an initial oxidation state (+V), Pu sorbed onto natural colloids, 190-nm and 500-nm diameter fluorescent Carboxylate Modified Latex (CML) microspheres, and tritium, as a conservative tracer, in saturated alluvium. The experiments were conducted in two columns having slightly different porosities at two flow rates, resulting in average linear velocities, v, of 0.6 to 3.65 cm/hr in one column and 0.57 to 2.85 cm/hr in the other. In all experiments, Pu associated with natural colloids transported through alluvium essentially unretarded, while dissolved Pu was entirely retained. These results were consistent with the strong sorption of Pu to alluvium and the negligible desorption from natural colloids, observed in separate batch experiments, over time scales exceeding those of the column experiments. The breakthrough of natural colloids preceded that of tritium in all experiments, indicating a slightly smaller effective pore volume for the colloids. The enhancement of colloids' transport over tritium decreased with v, implying ~40% enhancement at v = 0. The 500-nm CML microspheres were significantly attenuated in the column experiments compared to the 190-nm microspheres, which exhibited slightly more attenuation than natural colloids.

  7. 239+240Pu, 90Sr and 137Cs inventories in surface soils of Vietnam.

    PubMed

    Quang, N H; Long, N Q; Lieu, D B; Mai, T T; Ha, N T; Nhan, D D; Hien, P D

    2004-01-01

    Fallout 239+240Pu, 238Pu, 90Sr and 137Cs inventories in surface soils were measured for 20 locations in northern Vietnam yielding the mean values (+/- standard error) of 26.5+/-3.8 Bq m(-2) for 239+240Pu, 1048+/-143 Bq m(-2) for 137Cs and 212+/-28 Bq m(-2) for 90Sr. The concentrations of 137Cs and plutonium isotopes strongly correlate with each other resulting in a stable 239+240Pu/137Cs inventory ratio of 0.025+/-0.002. Among soil parameters, organic matter and fulvic acids strongly correlate with caesium and plutonium isotopes, especially in the 0-10 cm layer. 137Cs and 239+240Pu are distributed rather similarly over the 0-10 cm and 10-20 cm layers. At locations with high contents of sand (82-93%) along the South China Sea coast, the downward percolation by rainwater results in a higher accumulation of 239+240Pu and 137Cs in the 10-20 cm layer. The mean 137Cs/ 90Sr inventory ratio is 9.3+/-2.2, and the correlation is weak between these isotopes.

  8. Pu isotopes in the western North Pacific Ocean before the accident at Fukushima Dai-ichi Nuclear Power Station

    NASA Astrophysics Data System (ADS)

    Yamada, M.; Zheng, J.; Aono, T.

    2011-12-01

    Anthropogenic radionuclides such as Pu-239 (half-life: 24100 yr), Pu-240 (half-life: 6560 yr) and Pu-241 (half-life: 14.325 yr) mainly have been released into the environment as the result of atmospheric nuclear weapons testing. In the North Pacific Ocean, two distinct sources of Pu isotopes can be identified; i.e., the global stratospheric fallout and close-in tropospheric fallout from nuclear weapons testing at the Pacific Proving Grounds in the Marshall Islands. The atom ratio of Pu-240/Pu-239 is a powerful fingerprint to identify the sources of Pu in the ocean. The Pu-240/Pu-239 atom ratios in seawater and marine sediment samples collected in the western North Pacific before the accident at Fukushima Dai-ichi Nuclear Power Station will provide useful background data for understanding the process controlling Pu transport and for distinguishing future Pu sources. The atom ratios of Pu-240/Pu-239 in water columns from the Yamato and Tsushima Basins in the Japan Sea were significantly higher than the mean global fallout ratio of 0.18; however, there were no temporal variation of atom ratios during the period from 1984 to 1993 in the Japan Sea. The total Pu-239+240 inventories in the whole water columns were approximately doubled during the period from 1984 to 1993 in the two basins. The atom ratio of Pu-240/Pu-239 in surface water from Sagami Bay, western North Pacific Ocean, was 0.224 and showed no notable variation from the surface to the bottom with the mean atom ratio being 0.234. The atom ratios for the Pacific coast, near the Rokkasho nuclear fuel reprocessing plant, were approximately the same as the 0.224 ratio obtained from Sagami Bay, western North Pacific margin. The atom ratios in the surficial sediments from Sagami Bay ranged from 0.229 to 0.247. The mean atom ratio in the sediment columns in the East China Sea ranged from 0.248 for the Changjiang estuary to 0.268 for the shelf edge. The observed atom ratios were significantly higher than the mean

  9. PU.1 antisense lncRNA against its mRNA translation promotes adipogenesis in porcine preadipocytes.

    PubMed

    Wei, N; Wang, Y; Xu, R-X; Wang, G-Q; Xiong, Y; Yu, T-Y; Yang, G-S; Pang, W-J

    2015-04-01

    Antisense long non-coding RNAs (AS lncRNAs) play important roles in refined regulation of animal gene expression. However, their functions and molecular mechanisms for domestic animal adipogenesis are largely unknown. Here, we found a novel AS lncRNA transcribed from the porcine PU.1 gene (also known as SPI1) by strand-specific RT-PCR. Results showed that PU.1 AS lncRNA was expressed and generally lower than the level of PU.1 mRNA in porcine subcutaneous adipose, heart, liver, spleen, lympha, skeletal muscle and kidney tissues. We further found that the levels of PU.1 mRNA and PU.1 protein were significantly lower in subcutaneous and intermuscular adipose than in mesenteric and greater omentum adipose, whereas the levels of PU.1 AS lncRNA showed no difference in porcine adipose tissues from four different parts of the body. During porcine adipogenesis, levels of PU.1 mRNA increased at day 2 and then gradually decreased. Meanwhile, PU.1 AS lncRNA exhibited an expression trend similar to PU.1 mRNA but sharply decreased after day 2. Interestingly, PU.1 protein level rose during differentiation. In addition, at day 6 after differentiation, knockdown of endogenous PU.1 promoted adipogenesis, whereas knockdown of endogenous PU.1 AS lncRNA had the opposite effect. Moreover, peroxisome proliferator-activated receptor gamma (PPARG) and fatty acid synthase (FASN) were significantly upregulated in the PU.1 shRNA treatment group (P < 0.05), whereas they were downregulated in the PU.1 AS shRNA treatment group (P < 0.05). Adipose triglyceride lipase [ATGL; also known as patatin-like phospholipase domain containing 2 (PNPLA2)] and hormone-sensitive lipase [HSL; also known as lipase, hormone-sensitive (LIPE)] contrasted with PPARG and FASN. Finally, the PU.1 mRNA/PU.1 AS lncRNA duplex was detected by an endogenous ribonuclease protection assay combined with RT-PCR. Based on the above results, we suggest that PU.1 AS lncRNA (vs. its mRNA translation) promotes adipogenesis through

  10. Even-odd effects in prompt emission of spontaneously fissioning even-even Pu isotopes

    NASA Astrophysics Data System (ADS)

    Tudora, A.; Hambsch, F.-J.; Giubega, G.; Visan, I.

    2015-01-01

    The available experimental Y (A , TKE) data for 236,238,240,242,244Pu(SF) together with the Zp model prescription with appropriate parameters allows the investigation of even-odd effects in fragment distributions. The size of the global even-odd effect in Y (Z) is decreasing from 244Pu(SF) to 236Pu(SF) confirming the general observation of a decrease of the even-odd effect with the fissility parameter. Charge polarizations (ΔZ) and root-mean squares (rms) as a function of A of 236-244Pu(SF) were obtained for the first time. In the asymmetric fission region both ΔZ (A) and rms (A) exhibit oscillations with a periodicity of about 5 mass units due to the even-odd effects. The total average charge deviations < ΔZ > (obtained by averaging ΔZ (A) over the experimental Y (A) distribution) are of about |0.5| for all studied Pu(SF) systems. The comparison of the calculated ΔZ (A) and rms (A) of 240Pu(SF) with those of 239Pu (nth , f) reported by Wahl shows an in-phase oscillation with a higher amplitude in the case of 240Pu(SF), confirming the higher even-odd effect in the case of SF. As in the previously studied cases (233,235U (nth , f), 239Pu (nth , f), 252Cf(SF)) the even-odd effects in the prompt emission of 236-244Pu(SF) are mainly due to the Z even-odd effects in fragment distributions and charge polarizations and the N even-odd effects in the average neutron separation energies from fragments < Sn >. The size of the global N even-odd effect in < Sn > is decreasing with the fissility parameter, being higher for the Pu(SF) systems compared to the previously studied systems. The prompt neutron multiplicities as a function of Z, ν (Z), exhibit sawtooth shapes with a visible staggering for asymmetric fragmentations. The size of the global Z even-odd effect in ν (Z) exhibits a decreasing trend with increasing fissility. The average prompt neutron multiplicities as a function of TKE show an increase of the even-odd effect with increasing TKE, with global effect

  11. DETERMINATION OF 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

    SciTech Connect

    Maxwell, S.

    2010-07-26

    A new method for the determination of {sup 237}Np and Pu isotopes in large soil samples has been developed that provides enhanced uranium removal to facilitate assay by inductively coupled plasma mass spectrometry (ICP-MS). This method allows rapid preconcentration and separation of plutonium and neptunium in large soil samples for the measurement of {sup 237}Np and Pu isotopes by ICP-MS. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via {sup 238}U peak tailing. The method provides enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then transferring Pu to DGA resin for additional purification. The decontamination factor for removal of uranium from plutonium for this method is greater than 1 x 10{sup 6}. Alpha spectrometry can also be applied so that the shorter-lived {sup 238}Pu isotope can be measured successfully. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu and {sup 238}Pu were measured by alpha spectrometry.

  12. Heterogeneous Reduction of PuO2 with Fe(II): Importance of the Fe(III) Reaction Product

    SciTech Connect

    Felmy, Andrew R.; Moore, Dean A.; Rosso, Kevin M.; Qafoku, Odeta; Rai, Dhanpat; Buck, Edgar C.; Ilton, Eugene S.

    2011-05-01

    Abstract Heterogeneous reduction of actinides in higher and more soluble oxidation states to lower more insoluble oxidation states by reductants such as Fe(II) has been the subject of intensive study for more than two decades. However, Fe(II)-induced reduction of sparingly soluble Pu(IV) to the more soluble lower oxidation state Pu(III) has been much less studied even though such reactions can potentially increase the mobility of Pu in the subsurface. Thermodynamic calculations are presented that show how differences in the free energy of various possible solid-phase Fe(III) reaction products can greatly influence aqueous Pu(III) concentrations resulting from reduction of PuO2(am) by Fe(II). We present the first experimental evidence that reduction of PuO2(am) to Pu(III) by Fe(II) was enhanced when the Fe(III) mineral goethite was spiked into the reaction. The effect of goethite on reduction of Pu(IV) was demonstrated by measuring the time-dependence of total aqueous Pu concentration, its oxidation state, and system pe/pH. We also re-evaluated established protocols for determining Pu(III) [(Pu(III) + Pu(IV)) - Pu(IV)] by using thenoyltrifluoroacetone (TTA) in toluene extractions; the study showed that it is important to eliminate dissolved oxygen from the TTA solutions for accurate determinations. More broadly, this study highlights the importance of the Fe(III) reaction product in actinide reduction rate and extent by Fe(II).

  13. Gamma densitometer for measuring Pu density in fuel tubes

    SciTech Connect

    Winn, W.G.

    1982-01-01

    A fuel-gamma-densitometer (FGD) has been developed to examine nondestructively the uniformity of plutonium in aluminum-clad fuel tubes at the Savannah River Plant (SRP). The monitoring technique is ..gamma..-ray spectroscopy with a lead-collimated Ge(Li) detector. Plutonium density is correlated with the measured intensity of the 208 keV ..gamma..-ray from /sup 237/U (7d) of the /sup 241/Pu (15y) decay chain. The FGD measures the plutonium density within 0.125- or 0.25-inch-diameter areas of the 0.133- to 0.183-inch-thick tube walls. Each measurement yields a density ratio that relates the plutonium density of the measured area to the plutonium density in normal regions of the tube. The technique was used to appraise a series of fuel tubes to be irradated in an SRP reactor. High-density plutonium areas were initially identified by x-ray methods and then examined quantitatively with the FGD. The FGD reliably tested fuel tubes and yielded density ratios over a range of 0.0 to 2.5. FGD measurements examined (1) nonuniform plutonium densities or hot spots, (2) uniform high-density patches, and (3) plutonium density distribution in thin cladding regions. Measurements for tubes with known plutonium density agreed with predictions to within 2%. Attenuation measurements of the 208-keV ..gamma..-ray passage through the tube walls agreed to within 2 to 3% of calculated predictions. Collimator leakage measurements agreed with model calculations that predicted less than a 1.5% effect on plutonium density ratios. Finally, FGD measurements correlated well with x-ray transmission and fluoroscopic measurements. The data analysis for density ratios involved a small correction of about 10% for ..gamma..-shielding within the fuel tube. For hot spot examinations, limited information for this correction dictated a density ratio uncertainty of 3 to 5%.

  14. Chemically selective polymer substrate based direct isotope dilution alpha spectrometry of Pu.

    PubMed

    Paul, Sumana; Pandey, Ashok K; Shah, R V; Aggarwal, S K

    2015-06-01

    Quantification of actinides in the complex environmental, biological, process and waste streams samples requires multiple steps like selective preconcentration and matrix elimination, solid source preparations generally by evaporation or electrodeposition, and finally alpha spectrometry. To minimize the sample manipulation steps, a membrane based isotope dilution alpha spectrometry method was developed for the determination of plutonium concentrations in the complex aqueous solutions. The advantages of this method are that it is Pu(IV) selective at 3M HNO3, high preconcentration factor can be achieved, and obviates the need of solid source preparation. For this, a thin phosphate-sulfate bifunctional polymer layer was anchored on the surface of microporous poly(ethersulfone) membrane by UV induced surface grafting. The thickness of the bifunctional layer on one surface of the poly(ethersulfone) membrane was optimized. The thickness, physical and chemical structures of the bifunctional layer were studied by secondary ionization mass spectrometry (SIMS), scanning electron microscopy (SEM) and SEM-EDS (energy-dispersive spectroscopy). The optimized membrane was used for preconcentration of Pu(IV) from aqueous solutions having 3-4M HNO3, followed by direct quantification of the preconcentrated Pu(IV) by isotope dilution alpha spectrometry using (238)Pu spike. The chemical recovery efficiency of Pu(IV) was found to be 86±3% below Pu(IV) loading capacity (1.08 μg in 2×1 cm(2)) of the membrane sample. The experiments with single representative actinides indicated that Am(III) did not sorb to significant extent (7%) but U(VI) sorbed with 78±3% efficiency from the solutions having 3M HNO3 concentration. However, Pu(IV) chemical recovery in the membrane remained unaffected from the solution containing 1:1000 wt. proportion of Pu(IV) to U(VI). Pu concentrations in the (U, Pu)C samples and in the irradiated fuel dissolver solutions were determined. The results thus obtained

  15. Concordant 241Pu-241Am Dating of Environmental Samples: Results from Forest Fire Ash

    NASA Astrophysics Data System (ADS)

    Goldstein, S. J.; Oldham, W. J.; Murrell, M. T.; Katzman, D.

    2010-12-01

    We have measured the Pu, 237Np, 241Am, and 151Sm isotopic systematics for a set of forest fire ash samples from various locations in the western U.S. including Montana, Wyoming, Idaho, and New Mexico. The goal of this study is to develop a concordant 241Pu (t1/2 = 14.4 y)-241Am dating method for environmental collections. Environmental samples often contain mixtures of components including global fallout. There are a number of approaches for subtracting the global fallout component for such samples. One approach is to use 242Pu/239Pu as a normalizing isotope ratio in a three-isotope plot, where this ratio for the non-global fallout component can be estimated or assumed to be small. This study investigates a new, complementary method of normalization using the long-lived fission product, 151Sm (t1/2 = 90 y). We find that forest fire ash concentrates actinides and fission products with ~1E10 atoms 239Pu/g and ~1E8 atoms 151Sm/g, allowing us to measure these nuclides by mass spectrometric (MIC-TIMS) and radiometric (liquid scintillation counting) methods. The forest fire ash samples are characterized by a western U.S. regional isotopic signature representing varying mixtures of global fallout with a local component from atmospheric testing of nuclear weapons at the Nevada Test Site (NTS). Our results also show that 151Sm is well correlated with the Pu nuclides in the forest fire ash, suggesting that these nuclides have similar geochemical behavior in the environment. Results of this correlation indicate that the 151Sm/239Pu atom ratio for global fallout is ~0.164, in agreement with an independent estimate of 0.165 based on 137Cs fission yields for atmospheric weapons tests at the NTS. 241Pu-241Am dating of the non-global fallout component in the forest fire ash samples yield ages in the late 1950’s-early 1960’s, consistent with a peak in NTS weapons testing at that time. The age results for this component are in agreement using both 242Pu and 151Sm normalizations

  16. Chemically selective polymer substrate based direct isotope dilution alpha spectrometry of Pu.

    PubMed

    Paul, Sumana; Pandey, Ashok K; Shah, R V; Aggarwal, S K

    2015-06-01

    Quantification of actinides in the complex environmental, biological, process and waste streams samples requires multiple steps like selective preconcentration and matrix elimination, solid source preparations generally by evaporation or electrodeposition, and finally alpha spectrometry. To minimize the sample manipulation steps, a membrane based isotope dilution alpha spectrometry method was developed for the determination of plutonium concentrations in the complex aqueous solutions. The advantages of this method are that it is Pu(IV) selective at 3M HNO3, high preconcentration factor can be achieved, and obviates the need of solid source preparation. For this, a thin phosphate-sulfate bifunctional polymer layer was anchored on the surface of microporous poly(ethersulfone) membrane by UV induced surface grafting. The thickness of the bifunctional layer on one surface of the poly(ethersulfone) membrane was optimized. The thickness, physical and chemical structures of the bifunctional layer were studied by secondary ionization mass spectrometry (SIMS), scanning electron microscopy (SEM) and SEM-EDS (energy-dispersive spectroscopy). The optimized membrane was used for preconcentration of Pu(IV) from aqueous solutions having 3-4M HNO3, followed by direct quantification of the preconcentrated Pu(IV) by isotope dilution alpha spectrometry using (238)Pu spike. The chemical recovery efficiency of Pu(IV) was found to be 86±3% below Pu(IV) loading capacity (1.08 μg in 2×1 cm(2)) of the membrane sample. The experiments with single representative actinides indicated that Am(III) did not sorb to significant extent (7%) but U(VI) sorbed with 78±3% efficiency from the solutions having 3M HNO3 concentration. However, Pu(IV) chemical recovery in the membrane remained unaffected from the solution containing 1:1000 wt. proportion of Pu(IV) to U(VI). Pu concentrations in the (U, Pu)C samples and in the irradiated fuel dissolver solutions were determined. The results thus obtained

  17. Determination of 239Pu and 240Pu isotope ratio for a nuclear bomb particle using X-ray spectrometry in conjunction with γ-ray spectrometry and non-destructive α-particle spectrometry

    NASA Astrophysics Data System (ADS)

    Pöllänen, R.; Ruotsalainen, K.; Toivonen, H.

    2009-11-01

    A nuclear bomb particle from Thule containing Pu and U was analyzed using X-ray spectrometry in combination with γ-ray spectrometry and non-destructive α-spectrometry. The main objective was to investigate the possibility to determine the 239Pu and 240Pu isotope ratios. Previously, X-ray spectrometry together with the above-mentioned methods has been successfully applied for radiochemically processed samples, but not for individual particles. In the present paper we demonstrate the power of non-destructive analysis. The 239Pu/( 239Pu+ 240Pu) atom ratio for the Thule particle was determined, using two different approaches, to be 0.93±0.07 and 0.91±0.05. These results are consistent with weapons-grade material and the results obtained by other investigators.

  18. Measurement of the 240Pu/239Pu mass ratio using a transition-edge-sensor microcalorimeter for total decay energy spectroscopy

    DOE PAGES

    Hoover, Andrew S.; Bond, Evelyn M.; Croce, Mark P.; Holesinger, Terry G.; Kunde, Gerd J.; Rabin, Michael W.; Wolfsberg, Laura E.; Bennett, Douglas A.; Hays-Wehle, James P.; Schmidt, Dan R.; et al

    2015-02-27

    In this study, we have developed a new category of sensor for measurement of the 240Pu/239Pu mass ratio from aqueous solution samples with advantages over existing methods. Aqueous solution plutonium samples were evaporated and encapsulated inside of a gold foil absorber, and a superconducting transition-edge-sensor microcalorimeter detector was used to measure the total reaction energy (Q-value) of nuclear decays via heat generated when the energy is thermalized. Since all of the decay energy is contained in the absorber, we measure a single spectral peak for each isotope, resulting in a simple spectral analysis problem with minimal peak overlap. We foundmore » that mechanical kneading of the absorber dramatically improves spectral quality by reducing the size of radioactive inclusions within the absorber to scales below 50 nm such that decay products primarily interact with atoms of the host material. Due to the low noise performance of the microcalorimeter detector, energy resolution values of 1 keV fwhm (full width at half-maximum) at 5.5 MeV have been achieved, an order of magnitude improvement over α-spectroscopy with conventional silicon detectors. We measured the 240Pu/239Pu mass ratio of two samples and confirmed the results by comparison to mass spectrometry values. These results have implications for future measurements of trace samples of nuclear material.« less

  19. Measurement of the 240Pu/239Pu mass ratio using a transition-edge-sensor microcalorimeter for total decay energy spectroscopy.

    PubMed

    Hoover, Andrew S; Bond, Evelyn M; Croce, Mark P; Holesinger, Terry G; Kunde, Gerd J; Rabin, Michael W; Wolfsberg, Laura E; Bennett, Douglas A; Hays-Wehle, James P; Schmidt, Dan R; Swetz, Daniel; Ullom, Joel N

    2015-04-01

    We have developed a new category of sensor for measurement of the (240)Pu/(239)Pu mass ratio from aqueous solution samples with advantages over existing methods. Aqueous solution plutonium samples were evaporated and encapsulated inside of a gold foil absorber, and a superconducting transition-edge-sensor microcalorimeter detector was used to measure the total reaction energy (Q-value) of nuclear decays via heat generated when the energy is thermalized. Since all of the decay energy is contained in the absorber, we measure a single spectral peak for each isotope, resulting in a simple spectral analysis problem with minimal peak overlap. We found that mechanical kneading of the absorber dramatically improves spectral quality by reducing the size of radioactive inclusions within the absorber to scales below 50 nm such that decay products primarily interact with atoms of the host material. Due to the low noise performance of the microcalorimeter detector, energy resolution values of 1 keV fwhm (full width at half-maximum) at 5.5 MeV have been achieved, an order of magnitude improvement over α-spectroscopy with conventional silicon detectors. We measured the (240)Pu/(239)Pu mass ratio of two samples and confirmed the results by comparison to mass spectrometry values. These results have implications for future measurements of trace samples of nuclear material.

  20. Measurement of the 240Pu/239Pu mass ratio using a transition-edge-sensor microcalorimeter for total decay energy spectroscopy

    SciTech Connect

    Hoover, Andrew S.; Bond, Evelyn M.; Croce, Mark P.; Holesinger, Terry G.; Kunde, Gerd J.; Rabin, Michael W.; Wolfsberg, Laura E.; Bennett, Douglas A.; Hays-Wehle, James P.; Schmidt, Dan R.; Swetz, Daniel; Ullom, Joel N.

    2015-02-27

    In this study, we have developed a new category of sensor for measurement of the 240Pu/239Pu mass ratio from aqueous solution samples with advantages over existing methods. Aqueous solution plutonium samples were evaporated and encapsulated inside of a gold foil absorber, and a superconducting transition-edge-sensor microcalorimeter detector was used to measure the total reaction energy (Q-value) of nuclear decays via heat generated when the energy is thermalized. Since all of the decay energy is contained in the absorber, we measure a single spectral peak for each isotope, resulting in a simple spectral analysis problem with minimal peak overlap. We found that mechanical kneading of the absorber dramatically improves spectral quality by reducing the size of radioactive inclusions within the absorber to scales below 50 nm such that decay products primarily interact with atoms of the host material. Due to the low noise performance of the microcalorimeter detector, energy resolution values of 1 keV fwhm (full width at half-maximum) at 5.5 MeV have been achieved, an order of magnitude improvement over α-spectroscopy with conventional silicon detectors. We measured the 240Pu/239Pu mass ratio of two samples and confirmed the results by comparison to mass spectrometry values. These results have implications for future measurements of trace samples of nuclear material.

  1. Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

    NASA Astrophysics Data System (ADS)

    Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

    2005-02-01

    Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.

  2. DFT and two-dimensional correlation analysis methods for evaluating the Pu(3+)-Pu(4+) electronic transition of plutonium-doped zircon.

    PubMed

    Bian, Liang; Dong, Fa-qin; Song, Mian-xin; Dong, Hai-liang; Li, Wei-Min; Duan, Tao; Xu, Jin-bao; Zhang, Xiao-yan

    2015-08-30

    Understanding how plutonium (Pu) doping affects the crystalline zircon structure is very important for risk management. However, so far, there have been only a very limited number of reports of the quantitative simulation of the effects of the Pu charge and concentration on the phase transition. In this study, we used density functional theory (DFT), virtual crystal approximation (VCA), and two-dimensional correlation analysis (2D-CA) techniques to calculate the origins of the structural and electronic transitions of Zr1-cPucSiO4 over a wide range of Pu doping concentrations (c=0-10mol%). The calculations indicated that the low-angular-momentum Pu-fxy-shell electron excites an inner-shell O-2s(2) orbital to create an oxygen defect (VO-s) below c=2.8mol%. This oxygen defect then captures a low-angular-momentum Zr-5p(6)5s(2) electron to form an sp hybrid orbital, which exhibits a stable phase structure. When c>2.8mol%, each accumulated VO-p defect captures a high-angular-momentum Zr-4dz electron and two Si-pz electrons to create delocalized Si(4+)→Si(2+) charge disproportionation. Therefore, we suggest that the optimal amount of Pu cannot exceed 7.5mol% because of the formation of a mixture of ZrO8 polyhedral and SiO4 tetrahedral phases with the orientation (10-1). This study offers new perspective on the development of highly stable zircon-based solid solution materials.

  3. Goethite colloid enhanced Pu transport through a single saturated fracture in granite.

    PubMed

    Lin, Jianfeng; Dang, Haijun; Xie, Jinchuan; Li, Mei; Zhou, Guoqing; Zhang, Jihong; Zhang, Haitao; Yi, Xiaowei

    2014-08-01

    α-FeOOH, a stable iron oxide in nature, can strongly absorb the low-solubility plutonium (Pu) in aquifers. However, whether Pu transports though a single saturated fracture can be enhanced in the presence of α-FeOOH colloids remains unknown. Experimental studies were carried out to evaluate Pu mobilization at different water flow velocity, as affected by goethite colloids with various concentrations. Goethite nanorods were used to prepare (α-FeOOH)-associated Pu suspensions with α-FeOOH concentration of (0-150) mgL(-1). The work experimentally evidenced that α-FeOOH colloid does enhance transport of Pu through fractured granites. The fraction of mobile (239)Pu (RPu, m=41.5%) associated with the α-FeOOH of an extremely low colloid concentration (0.2mgL(-1)) is much larger than that in absence of α-FeOOH (RPu, m=6.98%). However, plutonium mobility began to decrease when α-FeOOH concentration was increased to 1.0mgL(-1). On the other hand, the fraction of mobile Pu increased gradually with the water flow velocity. Based on the experimental data, the mechanisms underlying the (α-FeOOH)-associated plutonium transport are comprehensively discussed in view of its dynamic deposition onto the granite surfaces, which is decided mainly by the relative interaction between the colloid particle and the immobile surface. This interaction is a balance of electrostatic force (may be repulsive or attractive), the van der Walls force, and the shear stress of flow. PMID:25016587

  4. Goethite colloid enhanced Pu transport through a single saturated fracture in granite.

    PubMed

    Lin, Jianfeng; Dang, Haijun; Xie, Jinchuan; Li, Mei; Zhou, Guoqing; Zhang, Jihong; Zhang, Haitao; Yi, Xiaowei

    2014-08-01

    α-FeOOH, a stable iron oxide in nature, can strongly absorb the low-solubility plutonium (Pu) in aquifers. However, whether Pu transports though a single saturated fracture can be enhanced in the presence of α-FeOOH colloids remains unknown. Experimental studies were carried out to evaluate Pu mobilization at different water flow velocity, as affected by goethite colloids with various concentrations. Goethite nanorods were used to prepare (α-FeOOH)-associated Pu suspensions with α-FeOOH concentration of (0-150) mgL(-1). The work experimentally evidenced that α-FeOOH colloid does enhance transport of Pu through fractured granites. The fraction of mobile (239)Pu (RPu, m=41.5%) associated with the α-FeOOH of an extremely low colloid concentration (0.2mgL(-1)) is much larger than that in absence of α-FeOOH (RPu, m=6.98%). However, plutonium mobility began to decrease when α-FeOOH concentration was increased to 1.0mgL(-1). On the other hand, the fraction of mobile Pu increased gradually with the water flow velocity. Based on the experimental data, the mechanisms underlying the (α-FeOOH)-associated plutonium transport are comprehensively discussed in view of its dynamic deposition onto the granite surfaces, which is decided mainly by the relative interaction between the colloid particle and the immobile surface. This interaction is a balance of electrostatic force (may be repulsive or attractive), the van der Walls force, and the shear stress of flow.

  5. Report on 238Pu(n,x) surrogate cross section measurement

    SciTech Connect

    Burke, J T; Ressler, J J; Henderson, R A; Scielzo, N D; Escher, J E; Thompson, I J; Gostic, J; Bleuel, D; Weideking, M; Bernstein, L A

    2010-03-31

    The goal of this year's effort is to measure the {sup 238}Pu(n,f) and {sup 238}Pu(n,2n) cross section from 100 keV to 20 MeV. We designed a surrogate experiment that used the reaction {sup 239}Pu(a,a{prime}x) as a surrogate for {sup 238}Pu(n,x). The experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory in January 2010. A description of the experiment and status of the data analysis is given. In order to obtain a reliable {sup 238}Pu(n,x) cross section we designed the experiment using the surrogate ratio technique. This technique allows one to measure a desired, unknown, cross section relative to a known cross section. In the present example, the {sup 238}Pu(n,x) cross section of interest is determined relative to the known {sup 235}U(n,x) cross section. To increase confidence in the results, and to reduce overall uncertainties, we are also determining the {sup 238}Pu(n,x) cross section relative to the known {sup 234}U(n,x) cross section. The compound nuclei of interest for this experiment were produced using inelastic alpha scattering. For example, {sup 236}U(a,a{prime}x) served as a surrogate for {sup 235}U(n,x); analogous reactions were considered for the other cross sections. Surrogate experiments determine the probabilities for the decay of the compound nuclei into the various channels of interest (fission, gamma decay) by measuring particle-fission (p-f) or particle?gamma (p?g) reaction spectra. By comparing the decay probabilities associated with the unknown cross section to that of a known cross section it is possible to obtain the ratio of these cross sections and thus determine the unknown, desired cross section.

  6. Development of prototype induced-fission-based Pu accountancy instrument for safeguards applications.

    PubMed

    Seo, Hee; Lee, Seung Kyu; An, Su Jung; Park, Se-Hwan; Ku, Jeong-Hoe; Menlove, Howard O; Rael, Carlos D; LaFleur, Adrienne M; Browne, Michael C

    2016-09-01

    Prototype safeguards instrument for nuclear material accountancy (NMA) of uranium/transuranic (U/TRU) products that could be produced in a future advanced PWR fuel processing facility has been developed and characterized. This is a new, hybrid neutron measurement system based on fast neutron energy multiplication (FNEM) and passive neutron albedo reactivity (PNAR) methods. The FNEM method is sensitive to the induced fission rate by fast neutrons, while the PNAR method is sensitive to the induced fission rate by thermal neutrons in the sample to be measured. The induced fission rate is proportional to the total amount of fissile material, especially plutonium (Pu), in the U/TRU product; hence, the Pu amount can be calibrated as a function of the induced fission rate, which can be measured using either the FNEM or PNAR method. In the present study, the prototype system was built using six (3)He tubes, and its performance was evaluated for various detector parameters including high-voltage (HV) plateau, efficiency profiles, dead time, and stability. The system's capability to measure the difference in the average neutron energy for the FNEM signature also was evaluated, using AmLi, PuBe, (252)Cf, as well as four Pu-oxide sources each with a different impurity (Al, F, Mg, and B) and producing (α,n) neutrons with different average energies. Future work will measure the hybrid signature (i.e., FNEM×PNAR) for a Pu source with an external interrogating neutron source after enlarging the cavity size of the prototype system to accommodate a large-size Pu source (~600g Pu).

  7. Development of prototype induced-fission-based Pu accountancy instrument for safeguards applications.

    PubMed

    Seo, Hee; Lee, Seung Kyu; An, Su Jung; Park, Se-Hwan; Ku, Jeong-Hoe; Menlove, Howard O; Rael, Carlos D; LaFleur, Adrienne M; Browne, Michael C

    2016-09-01

    Prototype safeguards instrument for nuclear material accountancy (NMA) of uranium/transuranic (U/TRU) products that could be produced in a future advanced PWR fuel processing facility has been developed and characterized. This is a new, hybrid neutron measurement system based on fast neutron energy multiplication (FNEM) and passive neutron albedo reactivity (PNAR) methods. The FNEM method is sensitive to the induced fission rate by fast neutrons, while the PNAR method is sensitive to the induced fission rate by thermal neutrons in the sample to be measured. The induced fission rate is proportional to the total amount of fissile material, especially plutonium (Pu), in the U/TRU product; hence, the Pu amount can be calibrated as a function of the induced fission rate, which can be measured using either the FNEM or PNAR method. In the present study, the prototype system was built using six (3)He tubes, and its performance was evaluated for various detector parameters including high-voltage (HV) plateau, efficiency profiles, dead time, and stability. The system's capability to measure the difference in the average neutron energy for the FNEM signature also was evaluated, using AmLi, PuBe, (252)Cf, as well as four Pu-oxide sources each with a different impurity (Al, F, Mg, and B) and producing (α,n) neutrons with different average energies. Future work will measure the hybrid signature (i.e., FNEM×PNAR) for a Pu source with an external interrogating neutron source after enlarging the cavity size of the prototype system to accommodate a large-size Pu source (~600g Pu). PMID:27337652

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

    SciTech Connect

    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.

  9. Detection and Quantification of Pu(III, IV, V, and VI) Using a1.0-meter Liquid Core Waveguide

    SciTech Connect

    Wilson, Richard E.; Hu, Yung-Jin; Nitsche, Heino

    2005-02-15

    Detection and quantification of the aquo ions of Pu in 1 MHClO4 was carried out using a 1-meter liquid core waveguide (LCW) coupledto a fiber optic UV-Vis spectrometer. Detection limits of 7 x 10-7 M forPu(VI), 1.6 x 10-5 M for Pu(V), 5 x 10-6 M for Pu(IV) and 8 x 10-6 M forPu(III) were achieved. The limits of detection represent increases of 18to 33 times those achievable using a conventional 1-cm path length.Because of the much lower detection limits of the LCW, routineidentification of the oxidation states in dilute Pu solutions can bemade.

  10. Np(V) and Pu(v) ion exchange and surface-mediated reduction mechanisms on montmorillonite.

    PubMed

    Zavarin, Mavrik; Powell, Brian A; Bourbin, Mathilde; Zhao, Pihong; Kersting, Annie B

    2012-03-01

    Due to their ubiquity and chemical reactivity, aluminosilicate clays play an important role in actinide retardation and colloid-facilitated transport in the environment. In this work, Pu(V) and Np(V) sorption to Na-montmorillonite was examined as a function of ionic strength, pH, and time. Np(V) sorption equilibrium was reached within 2 h. Sorption was relatively weak and showed a pH and ionic strength dependence. An approximate NpO(2)(+) → Na(+) Vanselow ion exchange coefficient (Kv) was determined on the basis of Np(V) sorption in 0.01 and 1.0 M NaCl solutions at pH < 5 (Kv ~ 0.3). In contrast to Np(V), Pu(V) sorption equilibrium was not achieved on the time-scale of weeks. Pu(V) sorption was much stronger than Np(V), and sorption rates exhibited both a pH and ionic strength dependence. Differences in Np(V) and Pu(V) sorption behavior are indicative of surface-mediated transformation of Pu(V) to Pu(IV) which has been reported for a number of redox-active and redox-inactive minerals. A model of the pH and ionic strength dependence of Pu(V) sorption rates suggests that H(+) exchangeable cations facilitate Pu(V) reduction. While surface complexation may play a dominant role in Pu sorption and colloid-facilitated transport under alkaline conditions, results from this study suggest that Pu(V) ion exchange and surface-mediated reduction to Pu(IV) can immobilize Pu or enhance its colloid-facilitated transport in the environment at neutral to mildly acidic pHs. PMID:22296270

  11. Transfer of aged Pu to cattle grazing on a contaminated environment

    SciTech Connect

    Gilbert, R.O.; Engel, D.W.; Smith, D.D.; Shinn, J.H.; Anspaugh, L.R.; Eisele, G.R.

    1988-03-01

    Estimates are obtained of the fraction of ingested or inhaled 239+240Pu transferred to blood and tissues of a reproducing herd of beef cattle, individuals of which grazed within fenced enclosures for up to 1064 d under natural conditions with no supplemental feeding at an arid site contaminated 16 y previously with Pu oxide. The estimated (geometric mean (GM)) fraction of Pu transferred from the gastrointestinal tract to blood serum was about 5 x 10(-6) (geometric standard error (GSE) = 1.4) with an approximate upper bound of about 2 x 10(-5). These results are in reasonable agreement with the value of 1 x 10(-5) recommended for human radiation protection purposes by the International Commission on Radiological Protection (ICRP) for insoluble Pu oxides that are free of very small particles. Also, results from a laboratory study by Stanley (St75), in which large doses of /sup 238/Pu were orally administered daily to dairy cattle for 19 consecutive days, suggest that aged 239+240Pu at this arid grazing site may not be more biologically available to blood serum than fresh 239+240Pu oxide. The estimated fractions of 239+240Pu transferred from blood serum to tissues of adult grazing cattle were: femur (3.2 X 10(-2), 1.8; GM, GSE), vertebra (1.4 X 10(-1), 1.6), liver (2.3 X 10(-1), 2.0), muscle (1.3 X 10(-1), 1.9), female gonads (7.9 X 10(-5), 1.5), and kidney (1.4 X 10(-3), 1.7). The blood-to-tissue fractional transfers for cattle initially exposed in utero were greater than those exposed only as adults by a factor of about 4 for femur (statistically significant) and of about 2 for other tissues (not significant). The estimated (GM) fraction of inhaled Pu initially deposited in the pulmonary lung was 0.34 (GSE = 1.3) for adults and 0.15 (GSE = 1.3) for cattle initially exposed in utero (a statistically significant difference).

  12. Photochemical valence adjustment of Pu and Np in nitric acid solution for separation and co-extraction

    SciTech Connect

    Wada, Y.; Morimoto, K.; Goibuchi, T.; Tomiyasu, H.

    1995-12-31

    Photochemical redox reaction tests were carried out where the experimental variables were irradiation rate using a Hg lamp light and molarity of nitric acid containing different reductant reagents such as hydroxylamine (HAN), hydrazine (HDZ) and urea. Based on these tests, the authors confirmed that the valences of Pu and Np were easily photochemically adjusted to two conditions of Pu(IV,VI)-Np(V) and Pu(IV,VI)-Np(VI), indicating that photochemical valence adjustment for the separation and co-extraction of Pu and Np has excellent potential as an advanced process technology.

  13. Determination of 241Pu in nuclear waste slurries: a comparative study using LSC and ICP-MS.

    PubMed

    Jäggi, M; Röllin, S; Alvarado, J A Corcho; Eikenberg, J

    2012-02-01

    (241)Pu was determined in slurry samples from a nuclear reactor decommissioning project at the Paul Scherrer Institute (Switzerland). To validate the results, the (241)Pu activities of five samples were determined by LSC (TriCarb and Quantulus) and ICP-MS, with each instrument at a different laboratory. In lack of certified reference materials for (241)Pu, the methods were further validated using the (241)Pu information values of two reference sediments (IAEA-300 and IAEA-384). Excellent agreement with the results was found between LSC and ICP-MS in the nuclear waste slurries and the reference sediments.

  14. Determination of 241Pu in nuclear waste slurries: a comparative study using LSC and ICP-MS.

    PubMed

    Jäggi, M; Röllin, S; Alvarado, J A Corcho; Eikenberg, J

    2012-02-01

    (241)Pu was determined in slurry samples from a nuclear reactor decommissioning project at the Paul Scherrer Institute (Switzerland). To validate the results, the (241)Pu activities of five samples were determined by LSC (TriCarb and Quantulus) and ICP-MS, with each instrument at a different laboratory. In lack of certified reference materials for (241)Pu, the methods were further validated using the (241)Pu information values of two reference sediments (IAEA-300 and IAEA-384). Excellent agreement with the results was found between LSC and ICP-MS in the nuclear waste slurries and the reference sediments. PMID:22079960

  15. Source term identification of environmental radioactive Pu/U particles by their characterization with non-destructive spectrochemical analytical techniques

    NASA Astrophysics Data System (ADS)

    Eriksson, M.; Osán, J.; Jernström, J.; Wegrzynek, D.; Simon, R.; Chinea-Cano, E.; Markowicz, A.; Bamford, S.; Tamborini, G.; Török, S.; Falkenberg, G.; Alsecz, A.; Dahlgaard, H.; Wobrauschek, P.; Streli, C.; Zoeger, N.; Betti, M.

    2005-04-01

    Six radioactive particles stemming from Thule area (NW-Greenland) were investigated by gamma-ray and L X-ray spectrometry based on radioactive disintegration, scanning electron microscopy coupled with energy-dispersive and wavelength-dispersive X-ray spectrometer, synchrotron radiation based techniques as microscopic X-ray fluorescence, microscopic X-ray absorption near-edge structure (μ-XANES) as well as combined X-ray absorption and fluorescence microtomography. Additionally, one particle from Mururoa atoll was examined by microtomography. From the results obtained, it was found out that the U and Pu were mixed in the particles. The U/Pu intensity ratios in the Thule particles varied between 0.05 and 0.36. The results from the microtomography showed that U/Pu ratio was not homogeneously distributed. The 241Am/ 238 + 239 + 240 Pu activity ratios varied between 0.13 and 0.17, indicating that the particles originate from different source terms. The oxidation states of U and Pu as determined by μ-XANES showed that U(IV) is the preponderant species and for Pu, two types of particles could be evidenced. One set had about 90% Pu(IV) while in the other the ratio Pu(IV)/Pu(VI) was about one third.

  16. Fabrication and characterization of electrospun biocompatible PU/PEGMA hybrid nanofibers by in-situ UV photopolymerization

    NASA Astrophysics Data System (ADS)

    Wang, HeYun; Feng, YaKai; Yuan, WenJie; Zhao, HaiYang; Fang, ZiChen; Khan, Musammir; Guo, JinTang

    2012-07-01

    Poly(ethylene glycol) methacrylate (PEGMA) was introduced into a polyurethane (PU) solution in order to prepare hemocompatible electrospun membranes for potential application as small diameter vascular scaffolds. Crosslinked PU/PEGMA hybrid nanofibers were fabricated by a reactive electrospinning process with N,N'-methylenebisacrylamide (MBAm) as crosslinker and benzophenone (BP) as photoinitiator. The photoinduced polymerization and crosslinking reaction took place simultaneously during the electrospinning process. No significant difference in the membrane morphology was found by SEM when PEGMA content was less than 20 wt%. The crosslinked fibrous membranes of PU/PEGMA exhibit higher hydrophilicity and mechanical strength than PU membrane. These nanofibrous membranes are potential substitutes for artificial vascular scaffolds.

  17. The differentiation effect of low-dose cytosine arabinoside is disturbed in PU.1-knockdown K562 cells.

    PubMed

    Nakano, Hiroko; Yanagita, Akane; Takahashi, Shinichiro

    2014-07-01

    We recently demonstrated by using PU.1-knockdown K562 (K562 PU.1KD) cells stably expressing PU.1 short inhibitory RNAs and PU.1-overexpressing K562 (K562 PU.1OE) cells, that therapeutic concentrations of 5-aza-2'-deoxycytidine (5-azadC) induce erythroid differentiation of these cells and that the PU.1 expression level is closely associated with the differentiating and apoptotic effects of 5-azadC on K562 cells. In this study, we investigated whether the effects of low-dose cytosine arabinoside (Ara-C), which is another erythroid differentiation inducer in K562 cells, is associated with the expression level of PU.1 in these cells. As a result, we demonstrated that the effect of Ara-C on cell viability and differentiation, as determined by the WST-8 assay and β-globin mRNA expression analysis, respectively, was suppressed in K562 PU.1KD cells compared to their controls. Collectively, these findings suggest that sufficient expression of PU.1 is indispensable for the erythroid differentiation of K562 cells.

  18. Distribution and source of (129)I, (239)(,240)Pu, (137)Cs in the environment of Lithuania.

    PubMed

    Ežerinskis, Ž; Hou, X L; Druteikienė, R; Puzas, A; Šapolaitė, J; Gvozdaitė, R; Gudelis, A; Buivydas, Š; Remeikis, V

    2016-01-01

    Fifty five soil samples collected in the Lithuania teritory in 2011 and 2012 were analyzed for (129)I, (137)Cs and Pu isotopes in order to investigate the level and distribution of artificial radioactivity in Lithuania. The activity and atomic ratio of (238)Pu/((239,24)0)Pu, (129)I/(127)I and (131)I/(137)Cs were used to identify the origin of these radionuclides. The (238)Pu/(239+240)Pu and (240)Pu/(239)Pu ratios in the soil samples analyzed varied in the range of 0.02-0.18 and 0.18-0.24, respectively, suggesting the global fallout as the major source of Pu in Lithuania. The values of 10(-9) to 10(-6) for (129)I/(127)I atomic ratio revealed that the source of (129)I in Lithuania is global fallout in most cases though several sampling sites shows a possible impact of reprocessing releases. Estimated (129)I/(131)I ratio in soil samples from the southern part of Lithuania shows negligible input of the Chernobyl fallout. No correlation of the (137)Cs and Pu isotopes with (129)I was observed, indicating their different sources terms. Results demonstrate uneven distribution of these radionuclides in the Lithuanian territory and several sources of contamination i.e. Chernobyl accident, reprocessing releases and global fallout.

  19. The Runx-PU.1 pathway preserves normal and AML/ETO9a leukemic stem cells.

    PubMed

    Staber, Philipp B; Zhang, Pu; Ye, Min; Welner, Robert S; Levantini, Elena; Di Ruscio, Annalisa; Ebralidze, Alexander K; Bach, Christian; Zhang, Hong; Zhang, Junyan; Vanura, Katrina; Delwel, Ruud; Yang, Henry; Huang, Gang; Tenen, Daniel G

    2014-10-01

    Runx transcription factors contribute to hematopoiesis and are frequently implicated in hematologic malignancies. All three Runx isoforms are expressed at the earliest stages of hematopoiesis; however, their function in hematopoietic stem cells (HSCs) is not fully elucidated. Here, we show that Runx factors are essential in HSCs by driving the expression of the hematopoietic transcription factor PU.1. Mechanistically, by using a knockin mouse model in which all three Runx binding sites in the -14kb enhancer of PU.1 are disrupted, we observed failure to form chromosomal interactions between the PU.1 enhancer and its proximal promoter. Consequently, decreased PU.1 levels resulted in diminished long-term HSC function through HSC exhaustion, which could be rescued by reintroducing a PU.1 transgene. Similarly, in a mouse model of AML/ETO9a leukemia, disrupting the Runx binding sites resulted in decreased PU.1 levels. Leukemia onset was delayed, and limiting dilution transplantation experiments demonstrated functional loss of leukemia-initiating cells. This is surprising, because low PU.1 levels have been considered a hallmark of AML/ETO leukemia, as indicated in mouse models and as shown here in samples from leukemic patients. Our data demonstrate that Runx-dependent PU.1 chromatin interaction and transcription of PU.1 are essential for both normal and leukemia stem cells.

  20. Resolving the Pu Electronic Structure Enigma: Past Lessons and Future Directions

    SciTech Connect

    Tobin, J G; Yu, S W; Chung, B W; Waddill, G D

    2008-05-30

    The nature of the 5f electronic structure of plutonium (Pu) remains unclear. [1] Despite many recent attempts to resolve the issue, a plethora of important unanswered questions remain. While many theoretical approaches to the problem have been promulgated, the real source of the difficulty is the absence of sufficient experimental benchmarking. This paucity of impact on the part of experimental results is driven in part by the difficulties of working with Pu: it is highly radioactive, biologically toxic, chemically reactive and restricted in its distribution and permitted access to user facilities. The results of these liabilities include the following: (1) it is very difficult, if not impossible, to get large single crystals of single phase samples and; (2) many state of the art experiments can not be done because general user facilities are not available for use with Pu samples. Additionally, there is the apparently bizarre nature of Pu, which seems to defeat the efforts to analyze it. A wonderful example of this is the absence of detailed and variant fine structure in many of the spectroscopic investigations of Pu.

  1. PU.1 and C/EBPalpha/beta convert fibroblasts into macrophage-like cells.

    PubMed

    Feng, Ru; Desbordes, Sabrina C; Xie, Huafeng; Tillo, Ester Sanchez; Pixley, Fiona; Stanley, E Richard; Graf, Thomas

    2008-04-22

    Earlier work has shown that the transcription factor C/EBPalpha induced a transdifferentiation of committed lymphoid precursors into macrophages in a process requiring endogenous PU.1. Here we have examined the effects of PU.1 and C/EBPalpha on fibroblasts, a cell type distantly related to blood cells and akin to myoblasts, adipocytes, osteoblasts, and chondroblasts. The combination of the two factors, as well as PU.1 and C/EBPbeta, induced the up-regulation of macrophage/hematopoietic cell surface markers in a large proportion of NIH 3T3 cells. They also up-regulated these markers in mouse embryo- and adult skin-derived fibroblasts. Based on cell morphology, activation of macrophage-associated genes, and extinction of fibroblast-associated genes, cell lines containing an attenuated form of PU.1 and C/EBPalpha acquired a macrophage-like phenotype. The lines also display macrophage functions: They phagocytose small particles and bacteria, mount a partial inflammatory response, and exhibit strict CSF-1 dependence for growth. The myeloid conversion is primarily induced by PU.1, with C/EBPalpha acting as a modulator of macrophage-specific gene expression. Our data suggest that it might become possible to induce the transdifferentiation of skin-derived fibroblasts into cell types desirable for tissue regeneration.

  2. Thermophysical properties and oxygen transport in (Thx,Pu1−x)O2

    PubMed Central

    Galvin, C. O. T.; Cooper, M. W. D.; Rushton, M. J. D.; Grimes, R. W.

    2016-01-01

    Using Molecular Dynamics, this paper investigates the thermophysical properties and oxygen transport of (Thx,Pu1−x)O2 (0 ≤ x ≤ 1) between 300–3500 K. In particular, the superionic transition is investigated and viewed via the thermal dependence of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure. Oxygen diffusivity and activation enthalpy are also investigated. Below the superionic temperature an increase of oxygen diffusivity for certain compositions of (Thx,Pu1−x)O2 compared to the pure end members is predicted. Oxygen defect formation enthalpies are also examined, as they underpin the superionic transition temperature and the increase in oxygen diffusivity. The increase in oxygen diffusivity for (Thx,Pu1−x)O2 is explained in terms of lower oxygen defect formation enthalpies for (Thx,Pu1−x)O2 than PuO2 and ThO2, while links are drawn between the superionic transition temperature and oxygen Frenkel disorder. PMID:27796314

  3. Pu-239+240 and Cs-137 in Montenegro soil: their correlation and origin.

    PubMed

    Antovic, Nevenka M; Vukotic, Perko; Svrkota, Nikola; Andrukhovich, Sergey K

    2012-08-01

    The (239+240)Pu activity concentrations in soil from Montenegro (six samples from three localities) have been measured for the first time. The alpha and gamma-spectrometric measurements are used to determine the (239+240)Pu/(137)Cs activity ratio, and it was found to be with an average of 0.02 and standard deviation of 0.007. This average activity ratio was applied to estimate (239+240)Pu in soil samples from the other 21 localities at which (137)Cs activity concentrations were measured. In this research obtained (either experimentally or estimated) (239+240)Pu activity concentrations (0.036-8.265 Bq kg(-1)) are comparable with those measured in some other European countries. On the basis of the results obtained in the present study and a survey of relevant literature, it is possible to conclude that Chernobyl contribution to (137)Cs contamination of Montenegro soils is dominant, whilst Pu contamination comes from the global fallout of nuclear weapon tests.

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

    SciTech Connect

    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

  5. PuReMD-GPU: A reactive molecular dynamics simulation package for GPUs

    SciTech Connect

    Kylasa, S.B.; Aktulga, H.M.; Grama, A.Y.

    2014-09-01

    We present an efficient and highly accurate GP-GPU implementation of our community code, PuReMD, for reactive molecular dynamics simulations using the ReaxFF force field. PuReMD and its incorporation into LAMMPS (Reax/C) is used by a large number of research groups worldwide for simulating diverse systems ranging from biomembranes to explosives (RDX) at atomistic level of detail. The sub-femtosecond time-steps associated with ReaxFF strongly motivate significant improvements to per-timestep simulation time through effective use of GPUs. This paper presents, in detail, the design and implementation of PuReMD-GPU, which enables ReaxFF simulations on GPUs, as well as various performance optimization techniques we developed to obtain high performance on state-of-the-art hardware. Comprehensive experiments on model systems (bulk water and amorphous silica) are presented to quantify the performance improvements achieved by PuReMD-GPU and to verify its accuracy. In particular, our experiments show up to 16× improvement in runtime compared to our highly optimized CPU-only single-core ReaxFF implementation. PuReMD-GPU is a unique production code, and is currently available on request from the authors.

  6. A comparison of fallout (236)U and (239)Pu uptake by Australian vegetation.

    PubMed

    Froehlich, M B; Dietze, M M A; Tims, S G; Fifield, L K

    2016-01-01

    The isotopes (236)U and (239)Pu, both produced during nuclear weapons tests carried out in the 1950s and 1960s, are present in the environment and may be used as tracers for soil erosion studies. Although these radionuclides occur only at ultra-trace levels in nature, they can be readily measured by accelerator mass spectrometry with the 14UD heavy ion accelerator at the Australian National University. We have analysed a series of vegetation samples for their (236)U and (239)Pu concentration and compared the results with those found in the surrounding soil. (236)U could be measured in all collected samples whereas (239)Pu could not be detected in several vegetation samples due to its very low concentration, although it was readily detectable in the soil. We find that, relative to plutonium, (236)U is preferentially taken up by plants with enrichment factors ((236)U/(239)Pu)veg/((236)U/(239)Pu)soil that range between 7 and 52 in the present study. PMID:26141188

  7. Designing of Multiphase Fly Ash/MWCNT/PU Composite Sheet Against Electromagnetic Environmental Pollution

    NASA Astrophysics Data System (ADS)

    Gujral, Parth; Varshney, Swati; Dhawan, S. K.

    2016-06-01

    Fly ash and multiwalled carbon nanotubes (MWCNT) reinforced multiphase polyurethane (PU) composite sheets have been fabricated by using a solution casting technique. Utilization of fly ash was the prime objective in order to reduce environmental pollution and to enhance the shielding properties of PU polymer. Our study proves that fly ash particles with MWCNTs in a PU matrix leads to novel hybrid high performance electromagnetic shielding interference material. Scanning electron microscopy confirms the existence of fly ash particles along with MWCNTs in a PU matrix. This multiphase composite shows total shielding effectiveness of 35.8 dB (>99.99% attenuation) in the Ku-band (12.4-18 GHz) frequency range. This is attributed to high dielectric losses of reinforcement present in the polymers matrix. The Nicolson-Ross-Weir algorithm has been applied to calculate the electromagnetic attributes and dielectric parameters of the PU samples by using scattering parameters ( S 11, S 22, S 12, S 21). The synthesized multiphase composites were further characterized by using x-ray diffraction, Fourier transform infrared spectroscopy, and thermo gravimetric analysis.

  8. Chemical bonds and vibrational properties of ordered (U, Np, Pu) mixed oxides

    NASA Astrophysics Data System (ADS)

    Yang, Yu; Zhang, Ping

    2013-01-01

    We use density functional theory +U to investigate the chemical bonding characters and vibrational properties of the ordered (U, Np, Pu) mixed oxides (MOXs), UNpO4,NpPuO4, and UPuO4. It is found that the 5f electronic states of different actinide elements keep their localized characters in all three MOXs. The occupied 5f electronic states of different actinide elements do not overlap with each other and tend to distribute over the energy band gap of the other actinide element's 5f states. As a result, the three ordered MOXs all show smaller band gaps than those of the component dioxides, with values of 0.91, 1.47, and 0.19 eV for UNpO4,NpPuO4, and UPuO4, respectively. Through careful charge density analysis, we further show that the U-O and Pu-O bonds in MOXs show more ionic character than in UO2 and PuO2, while the Np-O bonds show more covalent character than in NpO2. The change in covalencies in the chemical bonds leads to vibrational frequencies of oxygen atoms that are different in MOXs.

  9. The toxicity of inhaled particles of sup 238 PuO sub 2 in dogs

    SciTech Connect

    Muggenburg, B.A.; Guilmette, R.A.; Griffith, W.C. Jr.; Hahn, F.F.; Boecker, B.B. . Inhalation Toxicology Research Inst.); Gillett, N.A. )

    1991-01-01

    This study was conducted to determine the toxicity of inhaled {sup 238}PuO{sub 2} in the dog. Inhalation was selected because it is the mostly likely route of human exposure in the event of an accidental airborne release. Of 166 dog in the study, 72 inhaled 1.5{mu}m and 72 inhaled 3.0 {mu}m activity median aerodynamic diameter particles of {sup 238}PuO{sub 2}. Another 24 dogs inhaled the aerosol vector without plutonium. The aerosol exposures resulted in initial pulmonary burdens ranging from 37 to 0.11 and 55.5 to 0.37 kBq of {sup 238}Pu/kg body mass, of 1.5 {mu}m and 3.0 {mu}, particles, respectively. The particles dissolved slowly resulting in translocation of the Pu to liver, bone and other sites. The dogs were observed for biological effects over their life span. Necropsies were performed at death, and tissues were examined microscopically. The principal late-occurring effects were tumors of the lung, skeleton, and liver. Risk factors estimated for these cancers were 2800 lung cancers/10{sup 4} Gy, 800 liver cancers/10{sup 4} Gy, and 6200 bone cancers/10{sup 4} Gy for dogs. The potential hazard from {sup 238}Pu to humans may include tumors of the lung, bone and liver because of the likelihood of similarity of the dose patterns for the two species. 10 refs., 1 fig., 3 tabs.

  10. Hydrothermal synthesis, structure, and magnetic properties of Pu(SeO3)2

    SciTech Connect

    Bray, Travis H; Skanthakumar, S; Soderholm, L.; Sykora, Richard E.; Haire, Richard G.; Albrecht-Schmitt, Thomas E.

    2007-01-01

    The reaction between PuO2 and SeO2 under mild hydrothermal conditions results in the formation of Pu(SeO3)2 as brick-red prisms. This compound adopts the Ce(SeO3)2 structure type, and consists of one-dimensional chains of edge-sharing [PuO8] distorted bicapped trigonal prisms linked by [SeO3] units into a three-dimensional network. Crystallographic data: Pu(SeO3)2, monoclinic, space group P21/n, a 6.960(1) A , b 10.547(2) A , c 7.245(1) A , b 106.880(9)1, V 508.98(17) A 3, Z 4 (T 193 K), R(F) 2.92% for 83 parameters with 1140 re ections with I42s(I). Magnetic susceptibility data for Pu(SeO3)2 are linear from 35 to 320 K and yield an effective moment of 2.71(5) mB and a Weiss constant of -500(5) K.

  11. A comparison of fallout (236)U and (239)Pu uptake by Australian vegetation.

    PubMed

    Froehlich, M B; Dietze, M M A; Tims, S G; Fifield, L K

    2016-01-01

    The isotopes (236)U and (239)Pu, both produced during nuclear weapons tests carried out in the 1950s and 1960s, are present in the environment and may be used as tracers for soil erosion studies. Although these radionuclides occur only at ultra-trace levels in nature, they can be readily measured by accelerator mass spectrometry with the 14UD heavy ion accelerator at the Australian National University. We have analysed a series of vegetation samples for their (236)U and (239)Pu concentration and compared the results with those found in the surrounding soil. (236)U could be measured in all collected samples whereas (239)Pu could not be detected in several vegetation samples due to its very low concentration, although it was readily detectable in the soil. We find that, relative to plutonium, (236)U is preferentially taken up by plants with enrichment factors ((236)U/(239)Pu)veg/((236)U/(239)Pu)soil that range between 7 and 52 in the present study.

  12. Structure and phase stability of a Pu-0.32 wt% Ga alloy

    NASA Astrophysics Data System (ADS)

    Wheeler, D. W.; Ennaceur, S. M.; Matthews, M. B.; Roussel, P.; Bayer, P. D.

    2016-08-01

    In plutonium-gallium (Pu-Ga) alloys that have a Ga content of 0.3-0.4 wt%, their readiness to transform to α‧ renders them of particular interest in efforts to understand the tenuous nature of δ phase stability. The present study is a comprehensive examination of the structure and phase stability of a cast Pu-0.32 wt% Ga alloy, the Ga content being close to the minimum amount needed to retain the δ phase to ambient temperature. The alloy was characterised in both the as-cast condition as well as following a homogenising heat treatment. The 250-h heat treatment at 450 °C was shown to achieve an apparently stable δ-Pu phase. However, the stability of the δ-Pu phase was shown to be marginal: partial transformation to α‧-Pu was observed when the alloy was subjected to hydrostatic compression. Similar transformation was also apparent during metallographic preparation as well as during hardness indentation. The results provide new understanding of the nature of δ phase stability.

  13. Extension of 239+240Pu sediment geochronology to coarse-grained marine sediments

    USGS Publications Warehouse

    Kuehl, Steven A.; Ketterer, Michael E.; Miselis, Jennifer L.

    2012-01-01

    Sediment geochronology of coastal sedimentary environments dominated by sand has been extremely limited because concentrations of natural and bomb-fallout radionuclides are often below the limit of measurement using standard techniques. ICP-MS analyses of 239+240Pu from two sites representative of traditionally challenging (i.e., low concentration) environments provide a "proof of concept" and demonstrate a new application for bomb-fallout radiotracers in the study of sandy shelf-seabed dynamics. A kasten core from the New Zealand shelf in the Southern Hemisphere (low fallout), and a vibracore from the sandy nearshore of North Carolina (low particle surface area) both reveal measurable 239+240Pu activities at depth. In the case of the New Zealand site, independently verified steady-state sedimentation results in a 239+240Pu profile that mimics the expected atmospheric fallout. The depth profile of 239+240Pu in the North Carolina core is more uniform, indicating significant sediment resuspension, which would be expected in this energetic nearshore environment. This study, for the first time, demonstrates the utility of 239+240Pu in the study of sandy environments, significantly extending the application of bomb-fallout isotopes to coarse-grained sediments, which compose the majority of nearshore regions.

  14. Roles of RUNX1 and PU.1 in CCR3 Transcription.

    PubMed

    Kong, Su-Kang; Kim, Byung Soo; Hwang, Sae Mi; Lee, Hyune Hwan; Chung, Il Yup

    2016-06-01

    CCR3 is a chemokine receptor that mediates the accumulation of allergic inflammatory cells, including eosinophils and Th2 cells, at inflamed sites. The regulatory sequence of the CCR3 gene, contains two Runt-related transcription factor (RUNX) 1 sites and two PU.1 sites, in addition to a functional GATA site for transactivation of the CCR3 gene. In the present study, we examined the effects of the cis-acting elements of RUNX1 and PU.1 on transcription of the gene in EoL-1 eosinophilic cells and Jurkat T cells, both of which expressed functional surface CCR3 and these two transcription factors. Introduction of RUNX1 siRNA or PU.1 siRNA resulted in a modest decrease in CCR3 reporter activity in both cell types, compared with transfection of GATA-1 siRNA. Cotransfection of the two siRNAs led to inhibition in an additive manner. EMSA analysis showed that RUNX1, in particular, bound to its binding motifs. Mutagenesis analysis revealed that all point mutants lacking RUNX1- and PU.1-binding sites exhibited reduced reporter activities. These results suggest that RUNX1 and PU.1 participate in transcriptional regulation of the CCR3 gene.

  15. Identifying and localizing network problems using the PuNDIT project

    NASA Astrophysics Data System (ADS)

    Batista, Jorge; Dovrolis, Constantine; Lee, Danny; McKee, Shawn

    2015-12-01

    In today's world of distributed collaborations of scientists, there are many challenges to providing effective infrastructures to couple these groups of scientists with their shared computing and storage resources. The Pythia Network Diagnostic InfrasTructure (PuNDIT[1]) project is integrating and scaling research tools and creating robust code suitable for operational needs addressing the difficult challenge of automating the detection and location of network problems.PuNDIT is building upon the de-facto standard perfSONAR[2] network measurement infrastructure deployed in Open Science Grid(OSG)[3] and the Worldwide LHC Computing Grid(WLCG)[4]to gather and analyze complex real-world network topologies coupled with their corresponding network metrics to identify possible signatures of network problems from a set of symptoms. The PuNDIT Team is working closely with the perfSONAR developers from ESnet and Internet2 to integrate PuNDIT components as part of the perfSONAR Toolkit. A primary goal for PuNDIT is to convert complex network metrics into easily understood diagnoses in an automated way. We will report on the project progress to-date in working with the OSG and WLCG communities, describe the current implementation including some initial results and discuss future plans and the project timeline.

  16. Simultaneous determination of radiocesium ((135)Cs, (137)Cs) and plutonium ((239)Pu, (240)Pu) isotopes in river suspended particles by ICP-MS/MS and SF-ICP-MS.

    PubMed

    Cao, Liguo; Zheng, Jian; Tsukada, Hirofumi; Pan, Shaoming; Wang, Zhongtang; Tagami, Keiko; Uchida, Shigeo

    2016-10-01

    Due to radioisotope releases in the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, long-term monitoring of radiocesium ((135)Cs and (137)Cs) and Pu isotopes ((239)Pu and (240)Pu) in river suspended particles is necessary to study the transport and fate of these long-lived radioisotopes in the land-ocean system. However, it is expensive and technically difficult to collect samples of suspended particles from river and ocean. Thus, simultaneous determination of multi-radionuclides remains as a challenging topic. In this study, for the first time, we report an analytical method for simultaneous determination of radiocesium and Pu isotopes in suspended particles with small sample size (1-2g). Radiocesium and Pu were sequentially pre-concentrated using ammonium molybdophosphate and ferric hydroxide co-precipitation, respectively. After the two-stage ion-exchange chromatography separation from the matrix elements, radiocesium and Pu isotopes were finally determined by ICP-MS/MS and SF-ICP-MS, respectively. The interfering elements of U ((238)U(1)H(+) and (238)U(2)H(+) for (239)Pu and (240)Pu, respectively) and Ba ((135)Ba(+) and (137)Ba(+) for (135)Cs and (137)Cs, respectively) were sufficiently removed with the decontamination factors of 1-8×10(6) and 1×10(4), respectively, with the developed method. Soil reference materials were utilized for method validation, and the obtained (135)Cs/(137)Cs and (240)Pu/(239)Pu atom ratios, and (239+240)Pu activities showed a good agreement with the certified/information values. In addition, the developed method was applied to analyze radiocesium and Pu in the suspended particles of land water samples collected from Fukushima Prefecture after the FDNPP accident. The (135)Cs/(137)Cs atom ratios (0.329-0.391) and (137)Cs activities (23.4-152Bq/g) suggested radiocesium contamination of the suspended particles mainly originated from the accident-released radioactive contaminates, while similar Pu contamination of suspended

  17. Simultaneous determination of radiocesium ((135)Cs, (137)Cs) and plutonium ((239)Pu, (240)Pu) isotopes in river suspended particles by ICP-MS/MS and SF-ICP-MS.

    PubMed

    Cao, Liguo; Zheng, Jian; Tsukada, Hirofumi; Pan, Shaoming; Wang, Zhongtang; Tagami, Keiko; Uchida, Shigeo

    2016-10-01

    Due to radioisotope releases in the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, long-term monitoring of radiocesium ((135)Cs and (137)Cs) and Pu isotopes ((239)Pu and (240)Pu) in river suspended particles is necessary to study the transport and fate of these long-lived radioisotopes in the land-ocean system. However, it is expensive and technically difficult to collect samples of suspended particles from river and ocean. Thus, simultaneous determination of multi-radionuclides remains as a challenging topic. In this study, for the first time, we report an analytical method for simultaneous determination of radiocesium and Pu isotopes in suspended particles with small sample size (1-2g). Radiocesium and Pu were sequentially pre-concentrated using ammonium molybdophosphate and ferric hydroxide co-precipitation, respectively. After the two-stage ion-exchange chromatography separation from the matrix elements, radiocesium and Pu isotopes were finally determined by ICP-MS/MS and SF-ICP-MS, respectively. The interfering elements of U ((238)U(1)H(+) and (238)U(2)H(+) for (239)Pu and (240)Pu, respectively) and Ba ((135)Ba(+) and (137)Ba(+) for (135)Cs and (137)Cs, respectively) were sufficiently removed with the decontamination factors of 1-8×10(6) and 1×10(4), respectively, with the developed method. Soil reference materials were utilized for method validation, and the obtained (135)Cs/(137)Cs and (240)Pu/(239)Pu atom ratios, and (239+240)Pu activities showed a good agreement with the certified/information values. In addition, the developed method was applied to analyze radiocesium and Pu in the suspended particles of land water samples collected from Fukushima Prefecture after the FDNPP accident. The (135)Cs/(137)Cs atom ratios (0.329-0.391) and (137)Cs activities (23.4-152Bq/g) suggested radiocesium contamination of the suspended particles mainly originated from the accident-released radioactive contaminates, while similar Pu contamination of suspended

  18. Mapping ribonucleotides in genomic DNA and exploring replication dynamics by polymerase usage sequencing (Pu-seq).

    PubMed

    Keszthelyi, Andrea; Daigaku, Yasukazu; Ptasińska, Katie; Miyabe, Izumi; Carr, Antony M

    2015-11-01

    Ribonucleotides are frequently misincorporated into DNA during replication, and they are rapidly repaired by ribonucleotide excision repair (RER). Although ribonucleotides in template DNA perturb replicative polymerases and can be considered as DNA damage, they also serve positive biological functions, including directing the orientation of mismatch repair. Here we describe a method for ribonucleotide identification by high-throughput sequencing that allows mapping of the location of ribonucleotides across the genome. When combined with specific mutations in the replicative polymerases that incorporate ribonucleotides at elevated frequencies, our ribonucleotide identification method was adapted to map polymerase usage across the genome. Polymerase usage sequencing (Pu-seq) has been used to define, in unprecedented detail, replication dynamics in yeasts. Although other methods that examine replication dynamics provide direct measures of replication timing and indirect estimates of origin efficiency, Pu-seq directly ascertains origin efficiency. The Pu-seq protocol can be completed in 12-14 d.

  19. Molecular Structure and Bonding in Plutonium Carbides: A Theoretical Study of PuC3.

    PubMed

    Molpeceres, Germán; Rayón, Víctor M; Barrientos, Carmen; Largo, Antonio

    2016-04-14

    The most relevant species of plutonium tricarbide were characterized using theoretical methods. The global minimum is predicted to be a fan structure where the plutonium atom is bonded to a quasi-linear C3 unit. A rhombic isomer, shown to be a bicyclic species with transannular C-C bonding, lies about 39 kJ/mol above the fan isomer. A linear PuCCC isomer and a three-membered ring CPuC2 isomer were found to be higher in energy (150 and 195 kJ/mol, respectively, above the predicted global minimum). The possible processes for the formation of these species are discussed, and the IR spectra were predicted to help in possible experimental detection. The nature of the Pu-C interaction has been analyzed in terms of a topological analysis of the electronic density, showing that Pu-C bonding is essentially ionic with a certain degree of covalent character. PMID:27010701

  20. Correlation-induced anomalies and extreme sensitivity in fcc-PU1

    SciTech Connect

    Chen, Shao-ping

    2009-01-01

    We have used GGA + U density functional theory to study the effects of correlation on the properties offcc-Pu. We found that the structural and elastic properties offcc-Pu are highly sensitive to the Hubbard U parameter. Within an interval of 0.1 eV ofthe U parameter, the equilibrium lattice constants offcc-Pu can change from 0.44 to 0.47 nm. While the bulk modulus can drop by a factor of5 to 10. The pressure derivative, dB/dp, ofthe bulk modulus can rise dramatically from 5 to 16 and then drop to a negative value before recovering to a more normal value. These observations are partially supported by existing experiments and the prediction of a negative dB/dp needs to be tested in future experiments.