Science.gov

Sample records for alamos critical experiment

  1. Los Alamos Critical Experiments Facility. Quarterly progress report, January 1--March 31, 1993

    SciTech Connect

    Anderson, R.E.; Paternoster, R.R.; Robba, A.A.; Sanchez, R.G.; Butterfield, K.B.; Partain, B.Q.; Malenfant, R.E.

    1993-12-31

    The Los Alamos Critical Experiments Facility (LACEF) is now operating after a lengthy period of shutdown that lasted from November 1989 until June 1991. Since June 1991, the efforts of the staff have concentrated on bringing the assemblies back to operational status. The facility is fully operational and performing experiments. This progress report nominally covers the second quarter of FY93 (first quarter of calendar year 1993). It has sections on nuclear criticality safety classes, SHEBA II Project, Godiva IV activities, Skua activities, basic neutron physics measurements, etc.

  2. Dosimetry at the Los Alamos Critical Experiments Facility: Past, present, and future

    SciTech Connect

    Malenfant, R.E.

    1993-10-01

    Although the primary reason for the existence of the Los Alamos Critical Experiments Facility is to provide basic data on the physics of systems of fissile material, the physical arrangements and ability to provide sources of radiation have led to applications for all types of radiation dosimetry. In the broad definition of radiation phenomena, the facility has provided sources to evaluate biological effects, radiation shielding and transport, and measurements of basic parameters such as the evaluation of delayed neutron parameters. Within the last 15 years, many of the radiation measurements have been directed to calibration and intercomparison of dosimetry related to nuclear criticality safety. Future plans include (1) the new applications of Godiva IV, a bare-metal pulse assembly, for dosimetry (including an evaluation of neutron and gamma-ray room return); (2) a proposal to relocate the Health Physics Research Reactor from the Oak Ridge National Laboratory to Los Alamos, which will provide the opportunity to continue the application of a primary benchmark source to radiation dosimetry; and (3) a proposal to employ SHEBA, a low-enrichment solution assembly, for accident dosimetry and evaluation.

  3. Risk management for operations of the Los Alamos critical experiments facility

    SciTech Connect

    Paternoster, R.; Butterfield, K.

    1998-12-31

    The Los Alamos Critical Experiments Facility (LACEF) currently operates two burst reactors (Godiva-IV and Skua), one solution assembly (SHEBA 2--Solution high-Energy Burst Assembly), two fast-spectrum benchmark assemblies (Flattop and Big Ten), and five general-purpose remote assembly machines which may be configured with nuclear materials and assembled by remote control. SNM storage vaults support these and other operations at the site. With this diverse set of operations, several approaches are possible in the analysis and management of risk. The most conservative approach would be to write a safety analysis report (SAR) for each assembly and experiment. A more cost-effective approach is to analyze the probability and consequences of several classes of operations representative of operations on each critical assembly machine and envelope the bounding case accidents. Although the neutron physics of these machines varies widely, the operations performed at LACEF fall into four operational modes: steady-state mode, approach-to-critical mode, prompt burst mode, and nuclear material operations which can include critical assembly fuel loading. The operational sequences of each mode are very nearly the same, whether operated on one assembly machine or another. The use of an envelope approach to accident analysis is facilitated by the use of classes of operations and the use of bounding case consequence analysis. A simple fault tree analysis of operational modes helps resolve which operations are sensitive to human error and which are initiated by hardware of software failures. Where possible, these errors and failures are blocked by TSR LCOs.

  4. Los Alamos Critical Assemblies Facility

    SciTech Connect

    Malenfant, R.E.

    1981-06-01

    The Critical Assemblies Facility of the Los Alamos National Laboratory has been in existence for thirty-five years. In that period, many thousands of measurements have been made on assemblies of /sup 235/U, /sup 233/U, and /sup 239/Pu in various configurations, including the nitrate, sulfate, fluoride, carbide, and oxide chemical compositions and the solid, liquid, and gaseous states. The present complex of eleven operating machines is described, and typical applications are presented.

  5. Critical partnerships: Los Alamos, universities, and industry

    SciTech Connect

    Berger, C.L.

    1997-04-01

    Los Alamos National Laboratory, situated 35 miles northwest of Santa Fe, NM, is one of the Department of Energy`s three Defense Programs laboratories. It encompasses 43 square miles, employees approximately 10,000 people, and has a budget of approximately $1.1B in FY97. Los Alamos has a strong post-cold war mission, that of reducing the nuclear danger. But even with that key role in maintaining the nation`s security, Los Alamos views partnerships with universities and industry as critical to its future well being. Why is that? As the federal budget for R&D comes under continued scrutiny and certain reduction, we believe that the triad of science and technology contributors to the national system of R&D must rely on and leverage each others capabilities. For us this means that we will rely on these partners to help us in 5 key ways: We expect that partnerships will help us maintain and enhance our core competencies. In doing so, we will be able to attract the best scientists and engineers. To keep on the cutting edge of research and development, we have found that partnerships maintain the excellence of staff through new and exciting challenges. Additionally, we find that from our university and corporate partners we often learn and incorporate {open_quotes}best practices{close_quotes} in organizational management and operations. Finally, we believe that a strong national system of R&D will ensure and enhance our ability to generate revenues.

  6. Radiological dose assessment for bounding accident scenarios at the Critical Experiment Facility, TA-18, Los Alamos National Laboratory

    SciTech Connect

    1991-09-01

    A computer modeling code, CRIT8, was written to allow prediction of the radiological doses to workers and members of the public resulting from these postulated maximum-effect accidents. The code accounts for the relationships of the initial parent radionuclide inventory at the time of the accident to the growth of radioactive daughter products, and considers the atmospheric conditions at time of release. The code then calculates a dose at chosen receptor locations for the sum of radionuclides produced as a result of the accident. Both criticality and non-criticality accidents are examined.

  7. Exploration geochemistry: The Los Alamos experience

    SciTech Connect

    Maassen, L.W.; Bolivar, S.L.

    1989-01-01

    Los Alamos National Laboratory became actively involved in geochemical exploration in 1975 by conducting a reconnaissance-scale exploration program for uranium as part of the National Uranium Resource Evaluation program. Initially, only uranium and thorium were analyzed. By 1979 Los Alamos was analyzing a multielement suite. The data were presented in histograms and as black and white concentration plots for uranium and thorium only. Data for the remaining elements were presented as hard copy data listings in an appendix to the report. In 1983 Los Alamos began using exploration geochemistry for the purpose of finding economic mineral deposits to help stimulate the economies of underdeveloped countries. Stream-sediment samples were collected on the Caribbean island of St. Lucia and a geochemical atlas of that island was produced. The data were statistically smoothed and presented as computer-generated color plots of each element of the multielement suite. Studies for the US Bureau of Land Management in 1984 consisted of development of techniques for the integration of several large data sets, which could then be used for computer-assisted mineral resource assessments. A supervised classification technique was developed which compares the attributes of grid cells containing mines or mineral occurrences with attributes of unclassified cells not known to contain mines or occurrences. Color maps indicate how closely unclassified cells match in attributes the cells with mines or occurrences. 20 refs., 1 fig., 1 tab.

  8. Experience with confirmation measurement at Los Alamos

    SciTech Connect

    Marshall, R.S.; Wagner, R.P.; Hsue, F.

    1985-01-01

    Confirmation measurements are used at Los Alamos in support of incoming and outgoing shipment accountibility and for support of both at /sup 235/U and Pu inventories. Statistical data are presented to show the consistency of measurements on items of identical composition and on items measured at two facilitis using similar instruments. A description of confirmation measurement techniques used in support of /sup 235/U and Pu inventories and a discussion on the ability of the measurements to identify items with misstated SNM are given.

  9. Critical experiment data archiving

    SciTech Connect

    Koponen, B.L. ); Clayton, E.D.; Doherty, A.L. )

    1991-01-01

    Critical experiment facilities produced a large number of important data during the past 45 years; however, many useful data remain unpublished. The unpublished material exists in the form of experimenters' logbooks, notes, photographs, material descriptions, etc., This data could be important for computer code validation, understanding the physics of criticality, facility design, or for setting process limits. In the past, criticality specialists have been able to obtain unpublished details by direct contact with the experimenters. Obviously, this will not be possible indefinitely. Most of the US critical experiment facilities are now closed, and the experimenters are moving to other jobs, retiring, or otherwise becoming unavailable for this informal assistance. Also, the records are in danger of being discarded or lost during facility closures, cleanup activities, or in storage. A project was begun in 1989 to ensure that important unpublished data from critical experiment facilities in the United States are archived and made available as a resource of the US Department of Energy's (DOE's) Nuclear Criticality Information System (NCIS). The objective of this paper is to summarize the project accomplishments to date and bring these activities to the attention of those who might be aware of the location of source information needed for archiving and could assist in getting the materials included in the archive.

  10. National Criticality Experiments Research Center: Capability and Status

    SciTech Connect

    Hayes, David K.; Myers, William L.

    2012-07-12

    After seven years, the former Los Alamos Critical Experiments Facility (LACEF), or Pajarito Site, has reopened for business as the National Criticality Experiments Research Center (NCERC) at the Nevada National Security Site (NNSS). Four critical assembly machines (Comet, Planet, Flat-Top, and Godiva-IV) made the journey from Los Alamos to the NNSS. All four machines received safety system upgrades along with new digital control systems. Between these machines, systems ranging from the thermal through the intermediate to the fast spectrum may be assembled. Steady-State, transient, and super-prompt critical conditions may be explored. NCERC is the sole remaining facility in the United States capable of conducting general-purpose nuclear materials handling including the construction and operation of high-multiplication assemblies, delayed critical assemblies, and prompt critical assemblies. Reconstitution of the unique capabilities at NCERC ensures the viability of (1) The Nuclear Renaissance, (2) Stockpile Stewardship, and (3) and the next generation of criticality experimentalists.

  11. Critical mass experiment using U-235 foils and lucite plates

    SciTech Connect

    Sanchez, R.; Butterfield, K.; Kimpland, R.; Jaegers, P.

    1998-05-01

    The main objective of this experiment was to show how the multiplication of the system increases as moderated material is placed between highly enriched uranium foils. In addition, this experiment served to demonstrate the hand-stacking techniques, and approach to criticality by remote operation. This experiment was designed by Tom McLaughlin in the mid seventies as part of the criticality safety course that is taught at Los Alamos Critical Experiment Facility (LACEF). The W-U-235 ratio for this experiment was 215 which is where the minimum critical mass for this configuration occurs.

  12. Neutron Capture Experiments Using the DANCE Array at Los Alamos

    NASA Astrophysics Data System (ADS)

    Dashdorj, D.; Mitchell, G. E.; Baramsai, B.; Chyzh, A.; Walker, C.; Agvaanluvsan, U.; Becker, J. A.; Parker, W.; Sleaford, B.; Wu, C. Y.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wouters, J. M.; Krtička, M.; Bečvář, F.

    2009-03-01

    The Detector for Advanced Neutron Capture Experiments (DANCE) is designed for neutron capture measurements on very small and/or radioactive targets. The DANCE array of 160 BaF2 scintillation detectors is located at the Lujan Center at the Los Alamos Neutron Science Center (LANSCE). Accurate measurements of neutron capture data are important for many current applications as well as for basic understanding of neutron capture. The gamma rays following neutron capture reactions have been studied by the time-of-flight technique using the DANCE array. The high granularity of the array allows measurements of the gamma-ray multiplicity. The gamma-ray multiplicities and energy spectra for different multiplicities can be measured and analyzed for spin and parity determination of the resolved resonances.

  13. Neutron Capture Experiments Using the DANCE Array at Los Alamos

    SciTech Connect

    Dashdorj, D.; Mitchell, G. E.; Baramsai, B.; Chyzh, A.; Walker, C.; Agvaanluvsan, U.; Becker, J. A.; Parker, W.; Sleaford, B.; Wu, C. Y.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wouters, J. M.; Krticka, M.; Becvar, F.

    2009-03-31

    The Detector for Advanced Neutron Capture Experiments (DANCE) is designed for neutron capture measurements on very small and/or radioactive targets. The DANCE array of 160 BaF{sub 2} scintillation detectors is located at the Lujan Center at the Los Alamos Neutron Science Center (LANSCE). Accurate measurements of neutron capture data are important for many current applications as well as for basic understanding of neutron capture. The gamma rays following neutron capture reactions have been studied by the time-of-flight technique using the DANCE array. The high granularity of the array allows measurements of the gamma-ray multiplicity. The gamma-ray multiplicities and energy spectra for different multiplicities can be measured and analyzed for spin and parity determination of the resolved resonances.

  14. Nuclear criticality safety staff training and qualifications at Los Alamos National Laboratory

    SciTech Connect

    Monahan, S.P.; McLaughlin, T.P.

    1997-05-01

    Operations involving significant quantities of fissile material have been conducted at Los Alamos National Laboratory continuously since 1943. Until the advent of the Laboratory`s Nuclear Criticality Safety Committee (NCSC) in 1957, line management had sole responsibility for controlling criticality risks. From 1957 until 1961, the NCSC was the Laboratory body which promulgated policy guidance as well as some technical guidance for specific operations. In 1961 the Laboratory created the position of Nuclear Criticality Safety Office (in addition to the NCSC). In 1980, Laboratory management moved the Criticality Safety Officer (and one other LACEF staff member who, by that time, was also working nearly full-time on criticality safety issues) into the Health Division office. Later that same year the Criticality Safety Group, H-6 (at that time) was created within H-Division, and staffed by these two individuals. The training and education of these individuals in the art of criticality safety was almost entirely self-regulated, depending heavily on technical interactions between each other, as well as NCSC, LACEF, operations, other facility, and broader criticality safety community personnel. Although the Los Alamos criticality safety group has grown both in size and formality of operations since 1980, the basic philosophy that a criticality specialist must be developed through mentoring and self motivation remains the same. Formally, this philosophy has been captured in an internal policy, document ``Conduct of Business in the Nuclear Criticality Safety Group.`` There are no short cuts or substitutes in the development of a criticality safety specialist. A person must have a self-motivated personality, excellent communications skills, a thorough understanding of the principals of neutron physics, a safety-conscious and helpful attitude, a good perspective of real risk, as well as a detailed understanding of process operations and credible upsets.

  15. Reaction Rate Measurements at the National Criticality Experiments Research Center

    NASA Astrophysics Data System (ADS)

    Bredeweg, T. A.; Bounds, J. A.; Brooks, G. H., Jr.; Favorite, J. A.; Goda, J. M.; Hayes, D. K.; Jackman, K. R.; Little, R. C.; Macinnes, M. R.; Myers, W. L.; Oldham, W. J.; Rundberg, R. S.; Sanchez, R. G.; Schake, A. R.; White, M. C.; Wilkerson, C. W., Jr.

    2014-09-01

    With the resumption of regular operations of the Los Alamos Critical Assemblies at the National Criticality Experiments Research Center (NCERC), located at the Nevada National Security Site, we have embarked upon a series of campaigns to restore the capability to perform integral reaction rate and fission product yield measurements using historical radiochemical methods. This talk will present an overview of the current and future experimental plans, including results from our experimental campaigns on the Comet/Zeus and Flattop assemblies.

  16. Critical assembly: A technical history of Los Alamos during the Oppenheimer years, 1943--1945

    SciTech Connect

    Hoddeson, L.; Henriksen, P.W.; Meade, R.A.; Westfall, C.

    1993-11-01

    This volume treats the technical research that led to the first atomic bombs. The authors explore how the ``critical assembly`` of scientists, engineers, and military Personnel at Los Alamos collaborated during World War II, blending their traditions to create a new approach to large-scale research. The research was characterized by strong mission orientation, multidisciplinary teamwork, expansion of the scientists` traditional methodology with engineering techniques, and a trail-and-error methodology responding to wartime deadlines. The book opens with an introduction laying out major themes. After a synopsis of the prehistory of the bomb project, from the discovery of nuclear fission to the start of the Manhattan Engineer District, and an overview of the early materials program, the book examines the establishment of the Los Alamos Laboratory, the implosion and gun assembly programs, nuclear physics research, chemistry and metallurgy, explosives, uranium and plutonium development, confirmation of spontaneous fission in pile-produced plutonium, the thermonuclear bomb, critical assemblies, the Trinity test, and delivery of the combat weapons.

  17. History of critical experiments at Pajarito Site

    SciTech Connect

    Paxton, H.C.

    1983-03-01

    This account describes critical and subcritical assemblies operated remotely at the Pajarito Canyon Site at the Los Alamos National Laboratory. Earliest assemblies, directed exclusively toward the nuclear weapons program, were for safety tests. Other weapon-related assemblies provided neutronic information to check detailed weapon calculations. Topsy, the first of these critical assemblies, was followed by Lady Godiva, Jezebel, Flattop, and ultimately Big Ten. As reactor programs came to Los Alamos, design studies and mockups were tested at Pajarito Site. For example, nearly all 16 Rover reactors intended for Nevada tests were preceded by zero-power mockups and proof tests at Pajarito Site. Expanded interest and capability led to fast-pulse assemblies, culminating in Godiva IV and Skua, and to the Kinglet and Sheba solution assemblies.

  18. Critical mass experiment using {sup 235}U foils and lucite plates

    SciTech Connect

    Sanchez, R.; Butterfield, K.; Kimpland, R.; Jaegers, P.

    1998-09-01

    This experiment demonstrated how the neutron multiplication of a system increases as moderated material is placed between highly enriched uranium foils. In addition, this experiment served to demonstrate the hand-stacking technique and approach to criticality be remote operation. This experiment was designed by McLaughlin in the mid-seventies as part of the criticality safety course that is taught at the Los Alamos Critical Experiments Facility. The H/{sup 235}U ratio for this experiment was 215, which is the ratio at which the minimum critical mass for this configuration occurs.

  19. Subpicosecond compression experiments at Los Alamos National Laboratory

    SciTech Connect

    Carlsten, B.E.; Russell, S.J.; Kinross-Wright, J.M.

    1995-09-01

    The authors report on recent experiments using a magnetic chicane compressor at 8 MeV. Electron bunches at both low (0.1 nC) and high (1 nC) charges were compressed from 20 ps to less than 1 ps (FWHM). A transverse deflecting rf cavity was used to measure the bunch length at low charge; the bunch length at high charge was inferred from an induced energy spread of the beam. The longitudinal centrifugal-space charge force is calculated using a point-to-point numerical simulation and is shown not to influence the energy-spread measurement.

  20. Environmental assessment for consolidation of certain materials and machines for nuclear criticality experiments and training

    SciTech Connect

    1996-05-21

    In support of its assigned missions and because of the importance of avoiding nuclear criticality accidents, DOE has adopted a policy to reduce identifiable nuclear criticality safety risks and to protect the public, workers, government property and essential operations from the effects of a criticality accident. In support of this policy, the Los Alamos Critical Experiments Facility (LACEF) at the Los Alamos National Laboratory (LANL) Technical Area (TA) 18, provides a program of general purpose critical experiments. This program, the only remaining one of its kind in the United States, seeks to maintain a sound basis of information for criticality control in those physical situations that DOE will encounter in handling and storing fissionable material in the future, and ensuring the presence of a community of individuals competent in practicing this control.

  1. Review of the Los Alamos FRX-C experiment

    SciTech Connect

    Siemon, R.E.; Armstrong, W.T.; Barnes, D.C.; Bartsch, R.R.; Chrien, R.E.; Cochrane, J.C.; Hugrass, W.; Kewish, R.W.; Klingner, P.L.; Lewis, H.R.

    1985-01-01

    The FRX-C device is a large field-reversed theta pinch experiment, with linear dimensions twice those of its FRX-A and FRX-B predecessors. It is used to form field-reversed configurations (FRCs), which are high-beta, highly prolate compact toroids. FRX-C has demonstrated an R/sup 2/ scaling for particle confinement in FRCs, indicating particles are lost by diffusive processes. Particle losses were also observed to dominate the energy balance. FRC lifetimes exceeding 300 ..mu..s were observed when weak quadrupole fields were applied to stabilize the n = 2 rotational mode. Detailed studies of the FRC equilibrium were performed using multi-chord and holographic interferometry. Measurements of electron temperature by Thomson scattering showed a flat profile and substantial losses through the electron channel. The loss rate of the internal poloidal flux of the FRC was observed to be anomalous and to scale less strongly with temperature than predicted from classical resistivity.

  2. A Re-Analysis of Historical Los Alamos Critical Assembly Reaction Rate Measurements

    NASA Astrophysics Data System (ADS)

    Kahler, A. C.; MacInnes, M.; Chadwick, M. B.

    2016-02-01

    Starting in the 1950s and continuing into the early 1970s, a number of foil irradiations and fission chamber measurements were made in a variety of Fast critical assemblies at Los Alamos National Laboratory. These include (i) Godiva, a bare HEU spherical assembly; (ii) Flattop-25, a spherical assembly consisting of an HEU core and a natural uranium reflector; (iii) Jezebel, a bare 239Pu assembly; and (iv) Flattop-Pu, a spherical assembly consisting of a 239Pu core and a natural uranium reflector. In most instances the irradiations occur at or near the center of the assembly, but in selected instances data were obtained for a radial traverse extending into the Flattop reflector region. Measurements were made for a number of threshold reactions, including 45Sc(n,2n)44mSc, 51V(n,α)48Sc, 75As(n,2n)74As, 89Y(n,2n)88Y, 90Zr(n,2n)89Zr, 103Rh(n,2n)102gRh, 107Ag(n,2n)106mAg, 169Tm(n,2n)168Tm, 175Lu(n,2n)174Lu, 191Ir(n,2n)190Ir, 197Au(n,2n)196Au, 203Tl(n,2n)202Tl, 204Pb(n,2n)203Pb and 238U(n,2n)237U. Fission ratio data for 238U(n,f)/235U(n,f) and 239Pu(n,f)/235U(n,f) were also obtained. We report C/E values from MCNP6 calculations using ENDF/B-VII.1 and IRDFF-v1.03 cross section data.

  3. The transition to a revised quality assurance standard: The Los Alamos experience

    SciTech Connect

    Bolivar, S.L.; Clevenger, M.J.; Gillespie, P.F.; Day, J.L.

    1994-04-01

    On January 6, 1993 the Los Alamos Yucca Mountain Site Characterization Project (YMP) office received a directive to implement DOE/RW-0333P, Quality Assurance Requirements and Description. This document is a revised quality assurance standard containing the quality assurance requirements for the YMP. Forty-two Los Alamos quality assurance documents were affected by this directive. Our goal was to transition to the revised standard with minimal impact on research activities yet maintain maximum flexibility and efficiency. The process of transitioning to a revised quality assurance standard, in essence replacing an existing quality assurance program with a new program, was a unique learning experience. Although some problems were anticipated, the magnitude and complexity of problems was, at times, almost overwhelming. The problems encountered include the review process being more complex than anticipated; inconsistencies of much larger magnitude than originally believed; difficulties with electronic data base connections; quality processes being more complex than originally perceived, and administrative bottlenecks. The transition was very stressful and this was in part caused by the magnitude of the change. However, the transition process was enhanced by both a flexible schedule (provided by the customer) and flexibility in being able to revise procedures and modify processes. This allowed for minimal disruption to research activities. The new quality assurance program is better documented, therefore should be better understood by YMP personnel, is tracked electronically, and should provide a better product for the customer.

  4. MCNP{sup TM} criticality primer and training experiences

    SciTech Connect

    Briesmeister, J.; Forster, R.A.; Busch, R.

    1995-09-01

    With the closure of many experimental facilities, the nuclear criticality safety analyst is increasingly required to rely on computer calculations to identify safe limits for the handling and storage of fissile materials. However, the analyst may have little experience with the specific codes available at his or her facility. Usually, the codes are quite complex, black boxes capable of analyzing numerous problems with a myriad of input options. Documentation for these codes is designed to cover all the possible configurations and types of analyses but does not give much detail on any particular type of analysis. For criticality calculations, the user of a code is primarily interested in the value of the effective multiplication factor for a system (k{sub eff}). Most codes will provide this, and truckloads of other information that may be less pertinent to criticality calculations. Based on discussions with code users in the nuclear criticality safety community, it was decided that a simple document discussing the ins and outs of criticality calculations with specific codes would be quite useful. The Transport Methods Group, XTM, at Los Alamos National Laboratory (LANL) decided to develop a primer for criticality calculations with their Monte Carlo code, MCNP. This was a joint task between LANL with a knowledge and understanding of the nuances and capabilities of MCNP and the University of New Mexico with a knowledge and understanding of nuclear criticality safety calculations and educating first time users of neutronics calculations. The initial problem was that the MCNP manual just contained too much information. Almost everything one needs to know about MCNP can be found in the manual; the problem is that there is more information than a user requires to do a simple k{sub eff} calculation. The basic concept of the primer was to distill the manual to create a document whose only focus was criticality calculations using MCNP.

  5. Critical point wetting drop tower experiment

    NASA Technical Reports Server (NTRS)

    Kaukler, W. F.; Tcherneshoff, L. M.; Straits, S. R.

    1984-01-01

    Preliminary results for the Critical Point Wetting CPW Drop Tower Experiment are produced with immiscible systems. Much of the observed phenomena conformed to the anticipated behavior. More drops will be needed to test the CPW theory with these immiscible systems.

  6. Zeno: Critical Fluid Light Scattering Experiment

    NASA Technical Reports Server (NTRS)

    Gammon, Robert W.; Shaumeyer, J. N.; Briggs, Matthew E.; Boukari, Hacene; Gent, David A.; Wilkinson, R. Allen

    1996-01-01

    The Zeno (Critical Fluid Light Scattering) experiment is the culmination of a long history of critical fluid light scattering in liquid-vapor systems. The major limitation to making accurate measurements closer to the critical point was the density stratification which occurs in these extremely compressible fluids. Zeno was to determine the critical density fluctuation decay rates at a pair of supplementary angles in the temperature range 100 mK to 100 (mu)K from T(sub c) in a sample of xenon accurately loaded to the critical density. This paper gives some highlights from operating the instrument on two flights March, 1994 on STS-62 and February, 1996 on STS-75. More detail of the experiment Science Requirements, the personnel, apparatus, and results are displayed on the Web homepage at http://www.zeno.umd.edu.

  7. Risk management for operations of the LANL Critical Experiments Facility

    SciTech Connect

    Paternoster, R.; Butterfield, K.

    1998-12-31

    The Los Alamos Critical Experiments Facility (LACEF) currently operates two burst reactors (Godiva-IV and Skua), one solution assembly [the Solution High-Energy Burst Assembly (SHEBA)], two fast-spectrum benchmark assemblies (Flattop and Big Ten), and five general-purpose remote assembly machines that may be configured with nuclear materials and assembled by remote control. Special nuclear materials storage vaults support these and other operations at the site. With this diverse set of operations, several approaches are possible in the analysis and management of risk. The most conservative approach would be to write a safety analysis report (SAR) for each assembly and experiment. A more cost-effective approach is to analyze the probability and consequences of several classes of operations representative of operations on each critical assembly machine and envelope the bounding case accidents. Although the neutron physics of these machines varies widely, the operations performed at LACEF fall into four operational modes: steady-state mode, approach-to-critical mode, prompt burst mode, and nuclear material operations, which can include critical assembly fuel loading. The operational sequences of each mode are very nearly identical, whether operated on one assembly machine or another. The use of an envelope approach to accident analysis is facilitated by the use of classes of operations and the use of bounding case consequence analysis. A simple fault tree analysis of operational modes helps resolve which operations are sensitive to human error and which are initiated by hardware of software failures. Where possible, these errors and failures are blocked by TSR LCOs. Future work will determine the probability of accidents with various initiators.

  8. Critical experiments with mixed oxide fuel

    SciTech Connect

    Harris, D.R.

    1997-06-01

    This paper very briefly outlines technical considerations in performing critical experiments on weapons-grade plutonium mixed oxide fuel assemblies. The experiments proposed would use weapons-grade plutonium and Er{sub 2}O{sub 3} at various dissolved boron levels, and for specific fuel assemblies such as the ABBCE fuel assembly with five large water holes. Technical considerations described include the core, the measurements, safety, security, radiological matters, and licensing. It is concluded that the experiments are feasible at the Rensselaer Polytechnic Institute Reactor Critical Facility. 9 refs.

  9. Lawrence Livermore plutonium button critical experiment benchmark

    SciTech Connect

    Trumble, E.F.; Justice, J.B.; Frost, R.L.

    1994-12-31

    The end of the Cold War and the subsequent weapons reductions have led to an increased need for the safe storage of large amounts of highly enriched plutonium. In support of code validation required to address this need, a set of critical experiments involving arrays of weapons-grade plutonium metal that were performed at the Lawrence Livermore National Laboratory (LLNL) in the late 1960s has been revisited. Although these experiments are well documented, discrepancies and omissions have been found in the earlier reports. Many of these have been resolved in the current work, and these data have been compiled into benchmark descriptions. In addition, a computational verification has been performed on the benchmarks using multiple computer codes. These benchmark descriptions are also being made available to the US Department of Energy (DOE)-sponsored Nuclear Criticality Safety Benchmark Evaluation Working Group for dissemination in the DOE Handbook on Evaluated Criticality Safety Benchmark Experiments.

  10. ZENO: A Critical Fluid Light Scattering Experiment

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The ZENO experiment flew on the STS-62, it is designed to verify intriguing, but previously untested, theories in fluid physics. These theories attempt to describe dramatic changes in the properties of fluids near the critical temperature at which the vapor and liquid forms co-exist.

  11. SILENE Benchmark Critical Experiments for Criticality Accident Alarm Systems

    SciTech Connect

    Miller, Thomas Martin; Reynolds, Kevin H.

    2011-01-01

    In October 2010 a series of benchmark experiments was conducted at the Commissariat a Energie Atomique et aux Energies Alternatives (CEA) Valduc SILENE [1] facility. These experiments were a joint effort between the US Department of Energy (DOE) and the French CEA. The purpose of these experiments was to create three benchmarks for the verification and validation of radiation transport codes and evaluated nuclear data used in the analysis of criticality accident alarm systems (CAASs). This presentation will discuss the geometric configuration of these experiments and the quantities that were measured and will present some preliminary comparisons between the measured data and calculations. This series consisted of three single-pulsed experiments with the SILENE reactor. During the first experiment the reactor was bare (unshielded), but during the second and third experiments it was shielded by lead and polyethylene, respectively. During each experiment several neutron activation foils and thermoluminescent dosimeters (TLDs) were placed around the reactor, and some of these detectors were themselves shielded from the reactor by high-density magnetite and barite concrete, standard concrete, and/or BoroBond. All the concrete was provided by CEA Saclay, and the BoroBond was provided by Y-12 National Security Complex. Figure 1 is a picture of the SILENE reactor cell configured for pulse 1. Also included in these experiments were measurements of the neutron and photon spectra with two BICRON BC-501A liquid scintillators. These two detectors were provided and operated by CEA Valduc. They were set up just outside the SILENE reactor cell with additional lead shielding to prevent the detectors from being saturated. The final detectors involved in the experiments were two different types of CAAS detectors. The Babcock International Group provided three CIDAS CAAS detectors, which measured photon dose and dose rate with a Geiger-Mueller tube. CIDAS detectors are currently in

  12. In-plant experience with passive-active shufflers at Los Alamos

    SciTech Connect

    Hurd, J.R.; Hsue, F.; Rinard, P.M.

    1995-09-01

    Two Canberra-built passive-active {sup 252}Cf shufflers of Los Alamos hardware and software design have been installed at Los Alamos National Laboratory, one at the Chemistry and Metallurgy Research (CMR) Facility at TA-3 and the other at the Plutonium Facility (PF-4) at TA-55. These instruments fulfill important safeguards and accountability measurement requirements for special nuclear material (SNM) in matrices too dense or otherwise not appropriate for typical gamma-ray or other neutron counting techniques. They support many programmatic requirements including measurements of transuranic (TRU) waste and inventory verification. This paper describes the instrument performance under plant conditions with various background radiations on well-characterized standards to determine long-term stability and establish a calibration. Results are also reported on verification measurements of previously unmeasured inventory items in various matrices and geometric distributions. Preliminary investigative measurements are presented on standards of mixed uranium and plutonium oxide (MOX).

  13. Review of operating experience at the Los Alamos Plutonium Electrorefining Facility, 1963-1977

    SciTech Connect

    Mullins, L.J.; Morgan, A.N.

    1981-12-01

    This report reviews the operation of the Los Alamos Plutonium Electrorefining Plant at Technical Area 21 for the period 1964 through 1977. During that period, approximately 1568 kg of plutonium metal, > 99.95% pure, was produced in 653 runs from 1930 kg of metal fabrication scrap, 99% pure. General considerations of the electrorefining process and facility operation and recommendations for further improvement of the process are discussed.

  14. MCNP analysis of the FOEHN critical experiment

    SciTech Connect

    Ougouag, A.M.; Wemple, C.A.; Rubio, G.A.; Ryskamp, J.M.

    1993-10-01

    A very high fidelity MCNP model of the Franco-German FOEHN critical experiment has been developed. The results obtained show a high degree of agreement with each of the three configurations of the experiment. In particular, it is shown that the model reproduces the power density production distribution for all but a few of the experimental points internal to the core. Agreement for points of the axial ends at the core is less comprehensive. In the configurations that include boron axial core end covers, the agreement is similar within the core, but a few additional disagreement points arise at the axial ends of the core. The results remain consistent, however, with the statistical interpretation of MCNP tallies. The quantities computed also include the thermal flux in the reflector and the core multiplication factor for various critical configurations. It is found that the fluxes agree with the experiment within the experimental error bounds and two computational standard deviations. Most of the core multiplication results agree within three MCNP standard deviations. The overall conclusion of this study is that MCNP is an appropriate and valid computational tool for the static neutronic design of plate-fueled, heavy-water-moderated reactors, such as FOEHN or the Advanced Neutron Source.

  15. Critical point wetting drop tower experiment

    NASA Technical Reports Server (NTRS)

    Kaukler, William F.

    1990-01-01

    The 100 m Drop Tower at NASA-Marshall was used to provide the step change in acceleration from 1.0 to 0.0005 g. An inter-fluid meniscus oscillates vertically within a cylindrical container when suddenly released from earth's gravity and taken into a microgravity environment. Oscillations damp out from energy dissipative mechanisms such as viscosity and interfacial friction. Damping of the oscillations by the later mechanism is affected by the nature of the interfacial junction between the fluid-fluid interface and the container wall. In earlier stages of the project, the meniscus shape which developed during microgravity conditions was applied to evaluations of wetting phenomena near the critical temperature. Variations in equilibrium contact angle against the container wall were expected to occur under critical wetting conditions. However, it became apparent that the meaningful phenomenon was the damping of interfacial oscillations. This latter concept makes up the bulk of this report. Perfluoromethyl cyclohexane and isopropanol in glass were the materials used for the experiment. The wetting condition of the fluids against the wall changes at the critical wetting transition temperature. This change in wetting causes a change in the damping characteristics of the interfacial excursions during oscillation and no measurable change in contact angle. The effect of contact line friction measured above and below the wetting transition temperature was to increase the period of vertical oscillation for the vapor-liquid interface when below the wetting transition temperature.

  16. Energy supply and environmental issues: The Los Alamos National Laboratory experience in regional and international programs

    SciTech Connect

    Goff, S.J.

    1995-12-31

    The Los Alamos National Laboratory, operated by the University of California, encompasses more than forty-three square miles of mesas and canyons in northern New Mexico. A Department of Energy national laboratory, Los Alamos is one of the largest multidisciplinary, multiprogram laboratories in the world. Our mission, to apply science and engineering capabilities to problems of national security, has expanded to include a broad array of programs. We conduct extensive research in energy, nuclear safeguards and security, biomedical science, computational science, environmental protection and cleanup, materials science, and other basic sciences. The Energy Technology Programs Office is responsible for overseeing and developing programs in three strategic areas: energy systems and the environment, transportation and infrastructure, and integrated chemicals and materials processing. Our programs focus on developing reliable, economic and environmentally sound technologies that can help ensure an adequate supply of energy for the nation. To meet these needs, we are involved in programs that range from new and enhanced oil recovery technologies and tapping renewable energy sources, through efforts in industrial processes, electric power systems, clean coal technologies, civilian radioactive waste, high temperature superconductivity, to studying the environmental effects of energy use.

  17. A magnetospheric critical velocity experiment - Particle results

    NASA Technical Reports Server (NTRS)

    Torbert, R. B.; Newell, P. T.

    1986-01-01

    In March of 1983, a barium injection sounding rocket experiment (The Star of Lima) was conducted to investigate Alfven's critical ionization velocity (CIV) hypothesis in space. Included in the instrumented payload was a particle detection experiment consisting of five retarding potential analyzers. Despite conditions that appeared to be optimal for the critical velocity effect, the particle data, in agreement with optical observations, indicates that a fractional ionization of only approximately .0005 was observed, indicating that the conditions required for the effect to occur are still not well understood. However many of the required phenomena associated with the CIV effect were observed; in particular a superthermal electron population was formed at the expense of ion drift kinetic energy in the presence of intense electrostatic waves near the lower hybrid frequency. The amount of ionization produced is plausibly consistent with the observed electron flux, but could also be accounted for by residual solar UV at the injection point. It is shown based on the data set that one obvious explanation for the low ionization efficiency, namely that the ionizing superthermal electrons may rapidly escape along field lines, can be ruled out.

  18. The Zeus Copper/Uranium Critical Experiment at NCERC

    SciTech Connect

    Sanchez, Rene G.; Hayes, David K.; Bounds, John Alan; Jackman, Kevin R.; Goda, Joetta M.

    2012-06-15

    A critical experiment was performed to provide nuclear data in a non-thermal neutron spectrum and to reestablish experimental capability relevant to Stockpile Stewardship and Technical Nuclear Forensic programs. Irradiation foils were placed at specific locations in the Zeus all oralloy critical experiment to obtain fission ratios. These ratios were compared with others from other critical assemblies to assess the degree of softness in the neutron spectrum. This critical experiment was performed at the National Criticality Experiments Research Center (NCERC) in Nevada.

  19. Providing Nuclear Criticality Safety Analysis Education through Benchmark Experiment Evaluation

    SciTech Connect

    John D. Bess; J. Blair Briggs; David W. Nigg

    2009-11-01

    One of the challenges that today's new workforce of nuclear criticality safety engineers face is the opportunity to provide assessment of nuclear systems and establish safety guidelines without having received significant experience or hands-on training prior to graduation. Participation in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and/or the International Reactor Physics Experiment Evaluation Project (IRPhEP) provides students and young professionals the opportunity to gain experience and enhance critical engineering skills.

  20. Critical Thinking and Diversity Experiences: A Connection

    ERIC Educational Resources Information Center

    Inoue, Yukiko

    2005-01-01

    Critical thinking is an important learning outcome for college students. A review of the literature shows that this skill is affected by a number of factors, including exposure to cultural diversity. The University of Guam (UOG) located in the western Pacific is multicultural and multilingual. Using data from focus groups, this study examined the…

  1. Integrated Verification Experiment data collected as part of the Los Alamos National Laboratory's Source Region Program

    SciTech Connect

    Fitzgerald, T.J.; Carlos, R.C.; Argo, P.E.

    1993-01-21

    As part of the integrated verification experiment (IVE), we deployed a network of hf ionospheric sounders to detect the effects of acoustic waves generated by surface ground motion following underground nuclear tests at the Nevada Test Site. The network sampled up to four geographic locations in the ionosphere from almost directly overhead of the surface ground zero out to a horizontal range of 60 km. We present sample results for four of the IVEs: Misty Echo, Texarkana, Mineral Quarry, and Bexar.

  2. The impact and applicability of critical experiment evaluations

    SciTech Connect

    Brewer, R.

    1997-06-01

    This paper very briefly describes a project to evaluate previously performed critical experiments. The evaluation is intended for use by criticality safety engineers to verify calculations, and may also be used to identify data which need further investigation. The evaluation process is briefly outlined; the accepted benchmark critical experiments will be used as a standard for verification and validation. The end result of the project will be a comprehensive reference document.

  3. Summary Report of Laboratory Critical Experiment Analyses Performed for the Disposal Criticality Analysis Methodology

    SciTech Connect

    J. Scaglione

    1999-09-09

    This report, ''Summary Report of Laboratory Critical Experiment Analyses Performed for the Disposal Criticality Analysis Methodology'', contains a summary of the laboratory critical experiment (LCE) analyses used to support the validation of the disposal criticality analysis methodology. The objective of this report is to present a summary of the LCE analyses' results. These results demonstrate the ability of MCNP to accurately predict the critical multiplication factor (keff) for fuel with different configurations. Results from the LCE evaluations will support the development and validation of the criticality models used in the disposal criticality analysis methodology. These models and their validation have been discussed in the ''Disposal Criticality Analysis Methodology Topical Report'' (CRWMS M&O 1998a).

  4. Fiber Bragg grating sensing of detonation and shock experiments at Los Alamos National Laboratory

    NASA Astrophysics Data System (ADS)

    Rodriguez, G.; Sandberg, R. L.; Jackson, S. I.; Dattelbaum, D. M.; Vincent, S. W.; McCulloch, Q.; Martinez, R. M.; Gilbertson, S. M.; Udd, E.

    2013-05-01

    An all optical-fiber-based approach to measuring high explosive detonation front position and velocity is described. By measuring total light return using an incoherent light source reflected from a fiber Bragg grating sensor in contact with the explosive, dynamic mapping of the detonation front position and velocity versus time is obtained. We demonstrate two calibration procedures and provide several examples of detonation front measurements: PBX 9502 cylindrical rate stick, radial detonation front in PBX 9501, and PBX 9501 detonation along a curved meridian line. In the cylindrical rate stick measurement, excellent agreement with complementary diagnostics (electrical pins and streak camera imaging) is achieved, demonstrating accuracy in the detonation front velocity to below the 0.3% level when compared to the results from the pin data. In a similar approach, we use embedded fiber grating sensors for dynamic pressure measurements to test the feasibility of these sensors for high pressure shock wave research in gas gun driven flyer plate impact experiments. By applying well-controlled steady shock wave pressure profiles to soft materials such as PMMA, we study the dynamic pressure response of embedded fiber Bragg gratings to extract pressure amplitude of the shock wave. Comparison of the fiber sensor results is then made with traditional methods (velocimetry and electro-magnetic particle velocity gauges) to gauge the accuracy of the approach.

  5. Los Alamos Science: Number 23, 1995. Radiation protection and the human radiation experiments

    SciTech Connect

    Cooper, N.G.

    1995-12-31

    There are a variety of myths and misconceptions about the ionizing radiation that surrounds and penetrates us all. Dispel a few of these by taking a leisurely tour of radiation and its properties, of the natural and man-made sources of ionizing radiation, and of the way doses are calculated. By damaging DNA and inducing genetic mutations, ionizing radiation can potentially initiate a cell on the road to cancer. The authors review what is currently known about regulation of cellular reproduction, DNA damage and repair, cellular defense mechanisms, and the specific cancer-causing genes that are susceptible to ionizing radiation. A rapid survey of the data on radiation effects in humans shows that high radiation doses increase the risk of cancer, whereas the effects of low doses are very difficult to detect. The hypothetical risks at low doses, which are estimated from the atomic-bomb survivors, are compared to the low-dose data so that the reader can assess the present level of uncertainty. As part of the openness initiative, ten individuals who have worked with plutonium during various periods in the Laboratory`s history were asked to share their experiences including their accidental intakes. The history and prognosis of people who have had plutonium exposures is discussed by the Laboratory`s leading epidemiologist.

  6. Infrared spectrometry and radiometry of high-explosive detonations: the Los Alamos experiments

    SciTech Connect

    Rogers, E H; Williams, R L; Frazier, E N; Stone, D K; Herr, K C; Young, R M; Robbins, R G

    1982-11-01

    The purpose of these experiments was to determine whether the infrared spectra of high-explosive detonations can be used to infer the type of explosive material and/or the containment material employed. Infrared spectra and radiometric traces were measured during a test series of twenty-three detonations; some were contained and some uncontained. A variety of high-explosive materials and containment materials were included. The explosive charge was typically about 175 g. Infrared spectra were taken at the rate of 250 spectra/sec. This rate was too slow to characterize the very early gas expansion or burn pase of these explosions. The infrared spectra of the delayed or afterburn phase of these explosions often displayed molecular emission and absorption features. Absorption by NH/sub 3/ was observed when C-4 was the high-explosive material, and not observed for any other material. Emissions from H/sub 2/O and CO/sub 2/ were observed part of the time. Their occurence does not seem to be correlated with the type of containment or type of high-explosive material, or peak temperature reached in the afterburn. From the radiometric traces, one concludes that the relative peak radiance from the burn and afterburn phases depend strongly on the type of high-explosive material. For similar devices the burn phase is consistent from shot to shot, whereas the afterburn is very inconsistent. The answer to the question whether infrared spectra of high-explosive detonations can be used to infer the type of explosive material and/or the containment material must await spectral observations of the burn phase. We now believe that spectra of the burn phase are likely to be the ones most useful in identifying the high-explosive or containment material.

  7. Deconstructing Global Markets through Critical Performative Experiences in Puerto Rico

    ERIC Educational Resources Information Center

    Medina, Carmen Liliana; Weltsek, Gustave J.

    2013-01-01

    Critical Performative Pedagogies, the idea that "The nature of drama as a once removed creative experience turns non-critical implicit classroom identity formation into explicit identity performance as it asks participants to actively reflect upon how identity is created and engaged within fictional social interactions." (Weltsek and…

  8. Attachment Theory in Supervision: A Critical Incident Experience

    ERIC Educational Resources Information Center

    Pistole, M. Carole; Fitch, Jenelle C.

    2008-01-01

    Critical incident experiences are a powerful source of counselor development (T. M. Skovholt & P. R. McCarthy, 1988a, 1988b) and are relevant to attachment issues. An attachment theory perspective of supervision is presented and applied to a critical incident case scenario. By focusing on the behavioral systems (i.e., attachment, caregiving, and…

  9. Using Language Experience to ALERT Pupils' Critical Thinking Skills.

    ERIC Educational Resources Information Center

    Allen, Elizabeth Godwin; And Others

    1988-01-01

    Describes the "ALERT" procedure, whereby teachers may combine the language experience approach with the use of radio, television, newspaper, and magazine advertisements in a strategy that is useful for developing critical thinking skills, even in very young students. (ARH)

  10. Weightless experiments to probe universality of fluid critical behavior.

    PubMed

    Lecoutre, C; Guillaument, R; Marre, S; Garrabos, Y; Beysens, D; Hahn, I

    2015-06-01

    Near the critical point of fluids, critical opalescence results in light attenuation, or turbidity increase, that can be used to probe the universality of critical behavior. Turbidity measurements in SF6 under weightlessness conditions on board the International Space Station are performed to appraise such behavior in terms of both temperature and density distances from the critical point. Data are obtained in a temperature range, far (1 K) from and extremely close (a few μK) to the phase transition, unattainable from previous experiments on Earth. Data are analyzed with renormalization-group matching classical-to-critical crossover models of the universal equation of state. It results that the data in the unexplored region, which is a minute deviant from the critical density value, still show adverse effects for testing the true asymptotic nature of the critical point phenomena.

  11. Weightless experiments to probe universality of fluid critical behavior

    NASA Astrophysics Data System (ADS)

    Lecoutre, C.; Guillaument, R.; Marre, S.; Garrabos, Y.; Beysens, D.; Hahn, I.

    2015-06-01

    Near the critical point of fluids, critical opalescence results in light attenuation, or turbidity increase, that can be used to probe the universality of critical behavior. Turbidity measurements in SF6 under weightlessness conditions on board the International Space Station are performed to appraise such behavior in terms of both temperature and density distances from the critical point. Data are obtained in a temperature range, far (1 K) from and extremely close (a few μ K ) to the phase transition, unattainable from previous experiments on Earth. Data are analyzed with renormalization-group matching classical-to-critical crossover models of the universal equation of state. It results that the data in the unexplored region, which is a minute deviant from the critical density value, still show adverse effects for testing the true asymptotic nature of the critical point phenomena.

  12. Integrated Verification Experiment data collected as part of the Los Alamos National Laboratory`s Source Region Program. Appendix B: Surface ground motion

    SciTech Connect

    Weaver, T.A.; Baker, D.F.; Edwards, C.L.; Freeman, S.H.

    1993-10-01

    Surface ground motion was recorded for many of the Integrated Verification Experiments using standard 10-, 25- and 100-g accelerometers, force-balanced accelerometers and, for some events, using golf balls and 0.39-cm steel balls as surface inertial gauges (SIGs). This report contains the semi-processed acceleration, velocity, and displacement data for the accelerometers fielded and the individual observations for the SIG experiments. Most acceleration, velocity, and displacement records have had calibrations applied and have been deramped, offset corrected, and deglitched but are otherwise unfiltered or processed from their original records. Digital data for all of these records are stored at Los Alamos National Laboratory.

  13. Experience With the SCALE Criticality Safety Cross Section Libraries

    SciTech Connect

    Bowman, S.M.

    2000-08-21

    This report provides detailed information on the SCALE criticality safety cross-section libraries. Areas covered include the origins of the libraries, the data on which they are based, how they were generated, past experience and validations, and performance comparisons with measured critical experiments and numerical benchmarks. The performance of the SCALE criticality safety cross-section libraries on various types of fissile systems are examined in detail. Most of the performance areas are demonstrated by examining the performance of the libraries vs critical experiments to show general trends and weaknesses. In areas where directly applicable critical experiments do not exist, performance is examined based on the general knowledge of the strengths and weaknesses of the cross sections. In this case, the experience in the use of the cross sections and comparisons with the results of other libraries on the same systems are relied on for establishing acceptability of application of a particular SCALE library to a particular fissile system. This report should aid in establishing when a SCALE cross-section library would be expected to perform acceptably and where there are known or suspected deficiencies that would cause the calculations to be less reliable. To determine the acceptability of a library for a particular application, the calculational bias of the library should be established by directly applicable critical experiments.

  14. Review of critical velocity experiments in the ionosphere

    NASA Astrophysics Data System (ADS)

    Torbert, R. B.

    Observations relevant to Alfven's Critical Velocity Effect, of the several shaped-charge releases in the ionosphere are compared with three generations of a macroscopic model of these releases. Good agreement is found with experiments which have reported a low ion yield, but major discrepancies remain with the Porcupine experiment which has the largest yield yet reported.

  15. Review of critical velocity experiments in the ionosphere

    NASA Technical Reports Server (NTRS)

    Torbert, R. B.

    1990-01-01

    Observations relevant to Alfven's Critical Velocity Effect, of the several shaped-charge releases in the ionosphere are compared with three generations of a macroscopic model of these releases. Good agreement is found with experiments which have reported a low ion yield, but major discrepancies remain with the Porcupine experiment which has the largest yield yet reported.

  16. Validation of KENO V.a Comparison with Critical Experiments

    SciTech Connect

    Jordan, W.C.

    1999-01-01

    Section 1 of this report documents the validation of KENO V.a against 258 critical experiments. Experiments considered were primarily high or low enriched uranium systems. The results indicate that the KENO V.a Monte Carlo Criticality Program accurately calculates a broad range of critical experiments. A substantial number of the calculations showed a positive or negative bias in excess of 1 1/2% in k-effective (k{sub eff}). Classes of criticals which show a bias include 3% enriched green blocks, highly enriched uranyl fluoride slab arrays, and highly enriched uranyl nitrate arrays. If these biases are properly taken into account, the KENO V.a code can be used with confidence for the design and criticality safety analysis of uranium-containing systems. Section 2 of this report documents the results of investigation into the cause of the bias observed in Sect. 1. The results of this study indicate that the bias seen in Sect. 1 is caused by code bias, cross-section bias, reporting bias, and modeling bias. There is evidence that many of the experiments used in this validation and in previous validations are not adequately documented. The uncertainty in the experimental parameters overshadows bias caused by the code and cross sections and prohibits code validation to better than about 1% in k{sub eff}.

  17. Critical experiments analysis by ABBN-90 constant system

    SciTech Connect

    Tsiboulia, A.; Nikolaev, M.N.; Golubev, V.

    1997-06-01

    The ABBN-90 is a new version of the well-known Russian group-constant system ABBN. Included constants were calculated based on files of evaluated nuclear data from the BROND-2, ENDF/B-VI, and JENDL-3 libraries. The ABBN-90 is intended for the calculation of different types of nuclear reactors and radiation shielding. Calculations of criticality safety and reactivity accidents are also provided by using this constant set. Validation of the ABBN-90 set was made by using a computerized bank of evaluated critical experiments. This bank includes the results of experiments conducted in Russia and abroad of compact spherical assemblies with different reflectors, fast critical assemblies, and fuel/water-solution criticalities. This report presents the results of the calculational analysis of the whole collection of critical experiments. All calculations were produced with the ABBN-90 group-constant system. Revealed discrepancies between experimental and calculational results and their possible reasons are discussed. The codes and archives INDECS system is also described. This system includes three computerized banks: LEMEX, which consists of evaluated experiments and their calculational results; LSENS, which consists of sensitivity coefficients; and LUND, which consists of group-constant covariance matrices. The INDECS system permits us to estimate the accuracy of neutronics calculations. A discussion of the reliability of such estimations is finally presented. 16 figs.

  18. Criticality experiments and benchmarks for cross section evaluation: the neptunium case

    NASA Astrophysics Data System (ADS)

    Leong, L. S.; Tassan-Got, L.; Audouin, L.; Paradela, C.; Wilson, J. N.; Tarrio, D.; Berthier, B.; Duran, I.; Le Naour, C.; Stéphan, C.

    2013-03-01

    The 237Np neutron-induced fission cross section has been recently measured in a large energy range (from eV to GeV) at the n_TOF facility at CERN. When compared to previous measurement the n_TOF fission cross section appears to be higher by 5-7% beyond the fission threshold. To check the relevance of n_TOF data, we apply a criticality experiment performed at Los Alamos with a 6 kg sphere of 237Np, surrounded by enriched uranium 235U so as to approach criticality with fast neutrons. The multiplication factor ke f f of the calculation is in better agreement with the experiment (the deviation of 750 pcm is reduced to 250 pcm) when we replace the ENDF/B-VII.0 evaluation of the 237Np fission cross section by the n_TOF data. We also explore the hypothesis of deficiencies of the inelastic cross section in 235U which has been invoked by some authors to explain the deviation of 750 pcm. With compare to inelastic large distortion calculation, it is incompatible with existing measurements. Also we show that the v of 237Np can hardly be incriminated because of the high accuracy of the existing data. Fission rate ratios or averaged fission cross sections measured in several fast neutron fields seem to give contradictory results on the validation of the 237Np cross section but at least one of the benchmark experiments, where the active deposits have been well calibrated for the number of atoms, favors the n_TOF data set. These outcomes support the hypothesis of a higher fission cross section of 237Np.

  19. Validation of Cross Sections with Criticality Experiment and Reaction Rates: the Neptunium Case

    NASA Astrophysics Data System (ADS)

    Leong, L. S.; Tassan-Got, L.; Audouin, L.; Berthier, B.; Le Naour, C.; Stéphan, C.; Paradela, C.; Tarrío, D.; Duran, I.

    2014-04-01

    The 237Np neutron-induced fission cross section has been recently measured in a large energy range (from eV to GeV) at the n_TOF facility at CERN. When compared to previous measurements the n_TOF fission cross section appears to be higher by 5-7% beyond the fission threshold. To check the relevance of the n_TOF data, we considered a criticality experiment performed at Los Alamos with a 6 kg sphere of 237Np, surrounded by uranium highly enriched in 235U so as to approach criticality with fast neutrons. The multiplication factor keff of the calculation is in better agreement with the experiment when we replace the ENDF/B-VII.0 evaluation of the 237Np fission cross section by the n_TOF data. We also explored the hypothesis of deficiencies of the inelastic cross section in 235U which has been invoked by some authors to explain the deviation of 750 pcm. The large modification needed to reduce the deviation seems to be incompatible with existing inelastic cross section measurements. Also we show that the νbar of 237Np can hardly be incriminated because of the high accuracy of the existing data. Fission rate ratios or averaged fission cross sections measured in several fast neutron fields seem to give contradictory results on the validation of the 237Np cross section but at least one of the benchmark experiments, where the active deposits have been well calibrated for the number of atoms, favors the n_TOF data set. These outcomes support the hypothesis of a higher fission cross section of 237Np.

  20. Postanalysis of the CNPS (Compact Nuclear Power Source) critical experiment

    SciTech Connect

    Palmer, R.G.

    1988-01-01

    The Compact Nuclear Power Source (CNPS) was designed to produce electric power for remote sites where fuel logistics and costs would justify a remotely sited nuclear power plant. Since the reactor was of novel design with no appropriate benchmarks, a series of critical experiments was carried out at LANL. This paper describes the methodology and reports the results of the postanalysis that was performed on the critical experiments, which included several distinct critical configurations, the measurement of the isothermal temperature coefficient of reactivity and various material worths. Comparisons with measurements indicate that current methods and cross sections are adequate for calculating at least the beginning of life conditions in low enriched /sup 235/U-graphite cores. 7 refs., 4 figs., 4 tabs.

  1. Implementation and Critical Assessment of the Flipped Classroom Experience

    ERIC Educational Resources Information Center

    Scheg, Abigail G., Ed.

    2015-01-01

    In the past decade, traditional classroom teaching models have been transformed in order to better promote active learning and learner engagement. "Implementation and Critical Assessment of the Flipped Classroom Experience" seeks to capture the momentum of non-traditional teaching methods and provide a necessary resource for individuals…

  2. The Nuclear Criticality Information System's project to archive unpublished critical experiment data

    SciTech Connect

    Koponen, B.L. ); Clayton, E.D.; Doherty, A.L. )

    1991-07-01

    Critical experiment facilities produced a large amount of important data during the past forty-five years. However, much useful data remains unpublished. The unpublished material exists in the form of experimenters' logbooks, notes, photographs, material descriptions, etc. These data could be important for computer code validation, understanding the physics of criticality, facility design, or for setting process limits. In the past, criticality specialists have been able to obtain unpublished details by direct contact with the experimenters. Obviously, this will not be possible indefinitely. Most of the US critical experiment facilities are now closed, the experimenters are moving the other jobs, retiring, or otherwise becoming unavailable for this informal assistance. The closure of the facilities and the loss of personnel is likely to lead to the loss of the facility records unless an effort is made to assure that the records are preserved. It has been recognized for some time that the unpublished records of critical experiment facilities comprise a valuable resource, thus the Nuclear Criticality Information System (NCIS) is working to insure that the records are preserved and made available via NCIS. As a first step in the archiving project, we identified criteria to help judge which series of experiments should be considered for archiving. Data that are used for validating calculations or the basis for subcritical limits in standards, handbooks, and guides are of particular importance. In this paper we will discuss the criteria for archiving, the priority list of experiments for archiving, and progress in developing an NCIS image database using current CD-ROM technology.

  3. The Nuclear Criticality Information System`s project to archive unpublished critical experiment data

    SciTech Connect

    Koponen, B.L.; Clayton, E.D.; Doherty, A.L.

    1991-07-01

    Critical experiment facilities produced a large amount of important data during the past forty-five years. However, much useful data remains unpublished. The unpublished material exists in the form of experimenters` logbooks, notes, photographs, material descriptions, etc. These data could be important for computer code validation, understanding the physics of criticality, facility design, or for setting process limits. In the past, criticality specialists have been able to obtain unpublished details by direct contact with the experimenters. Obviously, this will not be possible indefinitely. Most of the US critical experiment facilities are now closed, the experimenters are moving the other jobs, retiring, or otherwise becoming unavailable for this informal assistance. The closure of the facilities and the loss of personnel is likely to lead to the loss of the facility records unless an effort is made to assure that the records are preserved. It has been recognized for some time that the unpublished records of critical experiment facilities comprise a valuable resource, thus the Nuclear Criticality Information System (NCIS) is working to insure that the records are preserved and made available via NCIS. As a first step in the archiving project, we identified criteria to help judge which series of experiments should be considered for archiving. Data that are used for validating calculations or the basis for subcritical limits in standards, handbooks, and guides are of particular importance. In this paper we will discuss the criteria for archiving, the priority list of experiments for archiving, and progress in developing an NCIS image database using current CD-ROM technology.

  4. The National Criticality Experiments Research Center at the Device Assembly Facility, Nevada National Security Site: Status and Capabilities, Summary Report

    SciTech Connect

    S. Bragg-Sitton; J. Bess; J. Werner

    2011-09-01

    The National Criticality Experiments Research Center (NCERC) was officially opened on August 29, 2011. Located within the Device Assembly Facility (DAF) at the Nevada National Security Site (NNSS), the NCERC has become a consolidation facility within the United States for critical configuration testing, particularly those involving highly enriched uranium (HEU). The DAF is a Department of Energy (DOE) owned facility that is operated by the National Nuclear Security Agency/Nevada Site Office (NNSA/NSO). User laboratories include the Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL). Personnel bring their home lab qualifications and procedures with them to the DAF, such that non-site specific training need not be repeated to conduct work at DAF. The NNSS Management and Operating contractor is National Security Technologies, LLC (NSTec) and the NNSS Safeguards and Security contractor is Wackenhut Services. The complete report provides an overview and status of the available laboratories and test bays at NCERC, available test materials and test support configurations, and test requirements and limitations for performing sub-critical and critical tests. The current summary provides a brief summary of the facility status and the method by which experiments may be introduced to NCERC.

  5. TRIGA Mark II Criticality Benchmark Experiment with Burned Fuel

    SciTech Connect

    Persic, Andreja; Ravnik, Matjaz; Zagar, Tomaz

    2000-12-15

    The experimental results of criticality benchmark experiments performed at the Jozef Stefan Institute TRIGA Mark II reactor are presented. The experiments were performed with partly burned fuel in two compact and uniform core configurations in the same arrangements as were used in the fresh fuel criticality benchmark experiment performed in 1991. In the experiments, both core configurations contained only 12 wt% U-ZrH fuel with 20% enriched uranium. The first experimental core contained 43 fuel elements with average burnup of 1.22 MWd or 2.8% {sup 235}U burned. The last experimental core configuration was composed of 48 fuel elements with average burnup of 1.15 MWd or 2.6% {sup 235}U burned. The experimental determination of k{sub eff} for both core configurations, one subcritical and one critical, are presented. Burnup for all fuel elements was calculated in two-dimensional four-group diffusion approximation using the TRIGLAV code. The burnup of several fuel elements was measured also by the reactivity method.

  6. Beryllium reflected cavity reactor for UF6 critical experiments

    NASA Technical Reports Server (NTRS)

    Jarvis, G. A.; Bernard, W.; Helmick, H. H.; White, R.

    1975-01-01

    Experiments and theoretical studies are being conducted for NASA on critical assemblies with one-meter diam by one-meter long low-density cores surrounded by a thick beryllium reflector. These assemblies make extensive use of existing nuclear propulsion reactor components, facilities, and instrumentation. Due to excessive porosity in the reflector, the initial critical mass was 19 kg U(93.2). Addition of a 17-cm-thick by 89-cm-diam beryllium flux trap in the cavity reduced the critical mass to 7 kg when all the uranium was in the zone just outside the flux trap. A mockup aluminum UF6 container was placed inside the flux trap and fueled with uranium-graphite elements. Fission distributions and reactivity worths of fuel and structural materials are available. These results will be used to guide the design of a prototype plasma core reactor which will test energy removal by optical radiation.

  7. Significant Learning Experiences in Ecohydrology in the Critical Zone

    NASA Astrophysics Data System (ADS)

    Lohse, K. A.

    2014-12-01

    We are integrating several significant learning experiences into the Reynolds Creek Critical Zone Observatory to engage the public, K-12, undergraduate and graduate students in ecohydrology in the critical zone. This observatory is meant to be a living laboratory for Idaho K-12 and college educators and support curriculum development for soil carbon for science education and centers. A new summer 2 week course in Environmental Field Methods is being developed and implemented to provide active learning experiences in soil and watershed hydrology, plant-water relations and carbon exchange, and soil descriptions. A graduate seminar has been implement to train graduate students in communicating science to the public and developing informal education such as exhibits to enhance active learning. Other educational outreach activities include adventure learning in the watershed by 8th graders from local school districts as well as public exhibits at environmental fairs, science festivals and communiversity events. These education and outreach activities are collectively targeted at engaging the public and new critical mass of graduate students and undergraduates in Critical Zone Science.

  8. Measurement of Critical Contact Angle in a Microgravity Space Experiment

    NASA Technical Reports Server (NTRS)

    Concus, P.; Finn, R.; Weislogel, M.

    1998-01-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USMT,2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  9. Measurement of Critical Contact Angle in a Microgravity Space Experiment

    NASA Technical Reports Server (NTRS)

    Concus, P.; Finn, R.; Weislogel, M.

    1998-01-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USML-2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  10. Measurement of critical contact angle in a microgravity space experiment

    NASA Astrophysics Data System (ADS)

    Concus, P.; Finn, R.; Weislogel, M.

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the NASA USML-2 Space Shuttle flight. The experiment's ``double proboscis'' containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  11. Measurement of critical contact angle in a microgravity space experiment

    SciTech Connect

    Concus, P.; Finn, R.; Weislogel, M.

    1999-06-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the NASA USML-2 Space Shuttle flight. The experiment's double proboscis containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  12. Parametric analyses of planned flowing uranium hexafluoride critical experiments

    NASA Technical Reports Server (NTRS)

    Rodgers, R. J.; Latham, T. S.

    1976-01-01

    Analytical investigations were conducted to determine preliminary design and operating characteristics of flowing uranium hexafluoride (UF6) gaseous nuclear reactor experiments in which a hybrid core configuration comprised of UF6 gas and a region of solid fuel will be employed. The investigations are part of a planned program to perform a series of experiments of increasing performance, culminating in an approximately 5 MW fissioning uranium plasma experiment. A preliminary design is described for an argon buffer gas confined, UF6 flow loop system for future use in flowing critical experiments. Initial calculations to estimate the operating characteristics of the gaseous fissioning UF6 in a confined flow test at a pressure of 4 atm, indicate temperature increases of approximately 100 and 1000 K in the UF6 may be obtained for total test power levels of 100 kW and 1 MW for test times of 320 and 32 sec, respectively.

  13. The Los Alamos Space Science Outreach (LASSO) Program

    NASA Astrophysics Data System (ADS)

    Barker, P. L.; Skoug, R. M.; Alexander, R. J.; Thomsen, M. F.; Gary, S. P.

    2002-12-01

    The Los Alamos Space Science Outreach (LASSO) program features summer workshops in which K-14 teachers spend several weeks at LANL learning space science from Los Alamos scientists and developing methods and materials for teaching this science to their students. The program is designed to provide hands-on space science training to teachers as well as assistance in developing lesson plans for use in their classrooms. The program supports an instructional model based on education research and cognitive theory. Students and teachers engage in activities that encourage critical thinking and a constructivist approach to learning. LASSO is run through the Los Alamos Science Education Team (SET). SET personnel have many years of experience in teaching, education research, and science education programs. Their involvement ensures that the teacher workshop program is grounded in sound pedagogical methods and meets current educational standards. Lesson plans focus on current LANL satellite projects to study the solar wind and the Earth's magnetosphere. LASSO is an umbrella program for space science education activities at Los Alamos National Laboratory (LANL) that was created to enhance the science and math interests and skills of students from New Mexico and the nation. The LASSO umbrella allows maximum leveraging of EPO funding from a number of projects (and thus maximum educational benefits to both students and teachers), while providing a format for the expression of the unique science perspective of each project.

  14. Critical fluid thermal equilibration experiment (19-IML-1)

    NASA Technical Reports Server (NTRS)

    Wilkinson, R. Allen

    1992-01-01

    Gravity sometimes blocks all experimental techniques of making a desired measurement. Any pure fluid possesses a liquid-vapor critical point. It is defined by a temperature, pressure, and density state in thermodynamics. The critical issue that this experiment attempts to understand is the time it takes for a sample to reach temperature and density equilibrium as the critical point is approached; is it infinity due to mass and thermal diffusion, or do pressure waves speed up energy transport while mass is still under diffusion control. The objectives are to observe: (1) large phase domain homogenization without and with stirring; (2) time evolution of heat and mass after temperature step is applied to a one phase equilibrium sample; (3) phase evolution and configuration upon going two phase from a one phase equilibrium state; (4) effects of stirring on a low g two phase configuration; (5) two phase to one phase healing dynamics starting from a two phase low g configuration; and (6) effects of shuttle acceleration events on spatially and temporally varying compressible critical fluid dynamics.

  15. What’s so critical about Critical Neuroscience? Rethinking experiment, enacting critique

    PubMed Central

    Fitzgerald, Des; Matusall, Svenja; Skewes, Joshua; Roepstorff, Andreas

    2014-01-01

    In the midst of on-going hype about the power and potency of the new brain sciences, scholars within “Critical Neuroscience” have called for a more nuanced and sceptical neuroscientific knowledge-practice. Drawing especially on the Frankfurt School, they urge neuroscientists towards a more critical approach—one that re-inscribes the objects and practices of neuroscientific knowledge within webs of social, cultural, historical and political-economic contingency. This paper is an attempt to open up the black-box of “critique” within Critical Neuroscience itself. Specifically, we argue that limiting enactments of critique to the invocation of context misses the force of what a highly-stylized and tightly-bound neuroscientific experiment can actually do. We show that, within the neuroscientific experiment itself, the world-excluding and context-denying “rules of the game” may also enact critique, in novel and surprising forms, while remaining formally independent of the workings of society, and culture, and history. To demonstrate this possibility, we analyze the Optimally Interacting Minds (OIM) paradigm, a neuroscientific experiment that used classical psychophysical methods to show that, in some situations, people worked better as a collective, and not as individuals—a claim that works precisely against reactionary tendencies that prioritize individual over collective agency, but that was generated and legitimized entirely within the formal, context-denying conventions of neuroscientific experimentation. At the heart of this paper is a claim that it was precisely the rigors and rules of the experimental game that allowed these scientists to enact some surprisingly critical, and even radical, gestures. We conclude by suggesting that, in the midst of large-scale neuroscientific initiatives, it may be “experiment”, and not “context”, that forms the meeting-ground between neuro-biological and socio-political research practices. PMID:24910605

  16. Electric field measurements during the Condor critical velocity experiment

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.; Pfaff, R. F.; Haerendel, G.

    1986-01-01

    The instrumentation of the Condor critical velocity Ba experiment (Wescott et al., 1986) for the measurements of the energetic particles and the electric field associated with a Ba explosion is described. The Ba explosion created a complex electric field pulse detected in situ by a single-axis double electric-field probe on a separate spacecraft. The measurements provide evidence of several important links in the critical-velocity chain, and are consistent with two hypotheses. The first hypothesis involves the creation of large polarization electric field due to charge separation; the second hypothesis implies a polarization of the beam by currents flowing across it. The chain of physical processes inferred from the observations is in agreement with most theories for the Alfven process.

  17. Forecast of criticality experiments and experimental programs needed to support nuclear operations in the United States of America: 1994--1999

    SciTech Connect

    Rutherford, D.

    1994-03-01

    This Forecast is generated by the Chair of the Experiment Needs Identification Workgroup (ENIWG), with input from Department of Energy and the nuclear community. One of the current concerns addressed by ENIWG was the Defense Nuclear Facilities Safety Board`s Recommendation 93-2. This Recommendation delineated the need for a critical experimental capability, which includes (1) a program of general-purpose experiments, (2) improving the information base, and (3) ongoing departmental programs. The nuclear community also recognizes the importance of criticality theory, which, as a stepping stone to computational analysis and safety code development, needs to be benchmarked against well-characterized critical experiments. A summary project of the Department`s needs with respect to criticality information includes (1) hands-on training, (2) criticality and nuclear data, (3) detector systems, (4) uranium- and plutonium-based reactors, and (5) accident analysis. The Workgroup has evaluated, prioritized, and categorized each proposed experiment and program. Transportation/Applications is a new category intended to cover the areas of storage, training, emergency response, and standards. This category has the highest number of priority-1 experiments (nine). Facilities capable of performing experiments include the Los Alamos Critical Experiment Facility (LACEF) along with Area V at Sandia National Laboratory. The LACEF continues to house the most significant collection of critical assemblies in the Western Hemisphere. The staff of this facility and Area V are trained and certified, and documentation is current. ENIWG will continue to work with the nuclear community to identify and prioritize experiments because there is an overwhelming need for critical experiments to be performed for basic research and code validation.

  18. The onset of visual experience gates auditory cortex critical periods

    PubMed Central

    Mowery, Todd M.; Kotak, Vibhakar C.; Sanes, Dan H.

    2016-01-01

    Sensory systems influence one another during development and deprivation can lead to cross-modal plasticity. As auditory function begins before vision, we investigate the effect of manipulating visual experience during auditory cortex critical periods (CPs) by assessing the influence of early, normal and delayed eyelid opening on hearing loss-induced changes to membrane and inhibitory synaptic properties. Early eyelid opening closes the auditory cortex CPs precociously and dark rearing prevents this effect. In contrast, delayed eyelid opening extends the auditory cortex CPs by several additional days. The CP for recovery from hearing loss is also closed prematurely by early eyelid opening and extended by delayed eyelid opening. Furthermore, when coupled with transient hearing loss that animals normally fully recover from, very early visual experience leads to inhibitory deficits that persist into adulthood. Finally, we demonstrate a functional projection from the visual to auditory cortex that could mediate these effects. PMID:26786281

  19. Star of Condor - A strontium critical velocity experiment, Peru, 1983

    NASA Technical Reports Server (NTRS)

    Wescott, E. M.; Stenbaek-Nielsen, H. C.; Hallinan, T.; Foeppl, H.; Valenzuela, A.

    1986-01-01

    'Star of Condor' was a critical velocity experiment using Sr vapor produced in a radial shaped charge, which was carried to 571.11 km altitude on a Taurus-Tomahawk rocket launched from Punto Lobos, Peru, and detonated in the plane of the magnetic field lines so that all ranges of pitch angles from parallel to B to perpendicular to B were covered. Sr has a critical velocity of 3.3 km/s, and from observation, 42.5 percent of the neutral Sr gas had a velocity component perpendicular to B exceeding that value. No Sr ion emissions were detected shortly after the burst with usual TV integration times. However, about 10 min after the detonation a faint field-aligned streak was discovered with long TV integration times. The brightness is estimated as 5 R, which, combined with the streak geometry, implies an ion production of 2.4 x 10 to the 19th ions. This is only 0.0036 percent ionization of the Sr vapor. All the ions could easily have been produced by thermal ionization from the original detonation thermal distribution. The breakup of the Sr gas into small bloblike structures may have allowed the high-energy electrons to escape before an ionization cascade could be produced. For whatever reason, the Alfven mechanism proposed for space plasmas in the absence of laboratory walls did not produce an ionization cascade in the experiment.

  20. Designing Critical Experiments in Support of Full Burnup Credit

    SciTech Connect

    Mueller, Don; Roberts, Jeremy A

    2008-01-01

    Burnup credit is the process of accounting for the negative reactivity due to fuel burnup and generation of parasitic absorbers over fuel assembly lifetime. For years, the fresh fuel assumption was used as a simple bound in criticality work for used fuel storage and transportation. More recently, major actinides have been included [1]. However, even this yields a highly conservative estimate in criticality calculations. Because of the numerous economical benefits including all available negative reactivity (i.e., full burnup credit) could provide [2], it is advantageous to work toward full burnup credit. Unfortunately, comparatively little work has been done to include non-major actinides and other fission products (FP) in burnup credit analyses due in part to insufficient experimental data for validation of codes and nuclear data. The Burnup Credit Criticality Experiment (BUCCX) at Sandia National Laboratory was a set of experiments with {sup 103}Rh that have relevance for burnup credit [3]. This work uses TSUNAMI-3D to investigate and adjust a BUCCX model to match isotope-specific, energy-dependent k{sub eff} sensitivity profiles to those of a representative high-capacity cask model (GBC-32) [4] for each FP of interest. The isotopes considered are {sup 149}Sm, {sup 143}Nd, {sup 103}Rh, {sup 133}Cs, {sup 155}Gd, {sup 152}Sm, {sup 99}Tc, {sup 145}Nd, {sup 153}Eu, {sup 147}Sm, {sup 109}Ag, {sup 95}Mo, {sup 150}Sm, {sup 101}Ru, and {sup 151}Eu. The goal is to understand the biases and bias uncertainties inherent in nuclear data, and ultimately, to apply these in support of full burnup credit.

  1. SR90, strontium shaped-charge critical ionization velocity experiment

    NASA Technical Reports Server (NTRS)

    Wescott, Eugene M.; Stenbaek-Nielsen, Hans; Swift, Daniel W.; Valenzuela, Arnoldo; Rees, David

    1990-01-01

    In May 1986 an experiment was performed to test Alfven's critical ionization velocity (CIV) effect in free space, using the first high explosive shaped charge with a conical liner of strontium metal. The release, made at 540 km altitude at dawn twilight, was aimed at 48 deg to B. The background electron density was 1.5 x 10(exp 4) cu cm. A faint field-aligned Sr(+) ion streak with tip velocity of 2.6 km/s was observed from two optical sites. Using two calibration methods, it was calculated that between 4.5 x 10(exp 20) and 2 x 10(exp 21) ions were visible. An ionization time constant of 1920 s was calculated for Sr from the solar UV spectrum and ionization cross section which combined with a computer simulation of the injection predicts 1.7 x 10(exp 21) solar UV ions in the low-velocity part of the ion streak. Thus all the observed ions are from solar UV ionization of the slow (less than critical) velocity portion of the neutral jet. The observed neutral Sr velocity distribution and computer simulations indicate that 2 x 10(exp 21) solar UV ions would have been created from the fast (greater than critical) part of the jet. They would have been more diffuse, and were not observed. Using this fact it was estimated that any CIV ions created were less than 10(exp 21). It was concluded that future Sr CIV free space experiments should be conducted below the UV shadow height and in much larger background plasma density.

  2. Experiences of critical care nurses caring for unresponsive patients.

    PubMed

    Villanueva, N E

    1999-08-01

    Grounded theory methodology was utilized to explore the experiences of critical care nurses caring for patients who were unable to respond due to a traumatic brain injury or receiving neuromuscular blocking agents. The registered nurses participating in the study worked in a neuroscience intensive care unit. Saturation of the categories was achieved with 16 interviews. The core category that emerged from the study is Giving the Patient a Chance. The subcategories of Learning about My Patient, Maintaining and Monitoring, Talking to My Patient, Working with Families, Struggling with Dilemmas and Personalizing the Experience all centered upon the focus of doing everything to help the patient attain the best possible outcome. Factors influencing each of the subcategories were identified such as the acuity of the patient, experience level of the nurse and the presence or absence of family members or significant others. These factors accounted for the variations in the nurses' experience. Several reasons accounting for the variations were determined. The study identified areas that need to be addressed in both general nursing education and nursing practice, such as instruction on talking to comatose patients, working with families and orientation information for nurses new to caring for these populations. Recommendations for improvement in these areas, as well as for future studies are discussed. PMID:10553569

  3. The Relationships of Critical Thinking Skills, Critical Thinking Dispositions, and College Experiences of Theological Students in Indonesia

    ERIC Educational Resources Information Center

    Soeherman, Sylvia

    2010-01-01

    The purposes of this study were to assess the critical thinking skills of theological students in Indonesia and to explore the relationships between these students' critical thinking skills and their demographic profiles, critical thinking dispositions, and college experiences. All third-year students who pursued either the Sarjana Theologi (a…

  4. Experience in applying the critical angle of reflectivity in NDT

    NASA Astrophysics Data System (ADS)

    Brokowski, A.; Deputat, J.

    1980-12-01

    Experience gained in the application of the critical angle of reflectivity technique as realized by an ultrasonic goniometer is reviewed. The goniometer is described as a one-probehead unit operating in the echo regime, and the operating principles of the device, which measures changes in the height of ultrasonic echos reflected from a sample-water interface as a function of sample rotation, are discussed. Examples of the application of the goniometer to determinations of the tensile strength of cast iron, the extent of cold working of stainless steel, the texture of rolled materials, extents of heat treatment, the hardness and velocity profiles of a cementation layer, surface layer thicknesses, and stresses in steels, and to the testing of bond quality and ceramics, semiconductors and plastics are presented.

  5. Nuclear criticality safety: 2-day training course

    SciTech Connect

    Schlesser, J.A.

    1997-02-01

    This compilation of notes is presented as a source reference for the criticality safety course. At the completion of this training course, the attendee will: be able to define terms commonly used in nuclear criticality safety; be able to appreciate the fundamentals of nuclear criticality safety; be able to identify factors which affect nuclear criticality safety; be able to identify examples of criticality controls as used as Los Alamos; be able to identify examples of circumstances present during criticality accidents; have participated in conducting two critical experiments; be asked to complete a critique of the nuclear criticality safety training course.

  6. Critical experiments at Sandia National Laboratories : technical meeting on low-power critical facilities and small reactors.

    SciTech Connect

    Harms, Gary A.; Ford, John T.; Barber, Allison Delo

    2010-11-01

    Sandia National Laboratories (SNL) has conducted radiation effects testing for the Department of Energy (DOE) and other contractors supporting the DOE since the 1960's. Over this period, the research reactor facilities at Sandia have had a primary mission to provide appropriate nuclear radiation environments for radiation testing and qualification of electronic components and other devices. The current generation of reactors includes the Annular Core Research Reactor (ACRR), a water-moderated pool-type reactor, fueled by elements constructed from UO2-BeO ceramic fuel pellets, and the Sandia Pulse Reactor III (SPR-III), a bare metal fast burst reactor utilizing a uranium-molybdenum alloy fuel. The SPR-III is currently defueled. The SPR Facility (SPRF) has hosted a series of critical experiments. A purpose-built critical experiment was first operated at the SPRF in the late 1980's. This experiment, called the Space Nuclear Thermal Propulsion Critical Experiment (CX), was designed to explore the reactor physics of a nuclear thermal rocket motor. This experiment was fueled with highly-enriched uranium carbide fuel in annular water-moderated fuel elements. The experiment program was completed and the fuel for the experiment was moved off-site. A second critical experiment, the Burnup Credit Critical Experiment (BUCCX) was operated at Sandia in 2002. The critical assembly for this experiment was based on the assembly used in the CX modified to accommodate low-enriched pin-type fuel in water moderator. This experiment was designed as a platform in which the reactivity effects of specific fission product poisons could be measured. Experiments were carried out on rhodium, an important fission product poison. The fuel and assembly hardware for the BUCCX remains at Sandia and is available for future experimentation. The critical experiment currently in operation at the SPRF is the Seven Percent Critical Experiment (7uPCX). This experiment is designed to provide benchmark

  7. Critical Incidents in Multicultural Training: An Examination of Student Experiences

    ERIC Educational Resources Information Center

    Coleman, M. Nicole

    2006-01-01

    This study examined critical incidents in graduate students' multicultural counseling training. Trainees (N=59) were asked to describe a critical incident and their multicultural training environment by responding to a critical incident protocol and the multicultural environment Inventory-Revised (D. B. Pope-Davis, W. M. Liu, J. Nevitt, & R. L.…

  8. Integrated verification experiment data collected as part of the Los Alamos National Laboratory`s Source Region program. Appendix F: Regional data from Lawrence Livermore National Laboratory and Sandia National Laboratory Seismic Networks

    SciTech Connect

    Taylor, S.R.

    1993-06-11

    A dataset of regional seismograms assembled for a series of Integrated Verification Experiments conducted by the Los Alamos National Laboratory Source Region program is described. The seismic data has been assembled from networks operated by Lawrence Livermore National Laboratory and Sandia National Laboratory. Examples of the data are shown and basic recording characteristics of the network are described. The seismograms are available on a data tape in SAC format upon request.

  9. Critical technology experiment results for lightweight space heat receiver

    NASA Astrophysics Data System (ADS)

    Schneider, Michael G.; Brege, Mark A.; Heidenreich, Gary R.

    Critical technology experiments have been performed on thermal energy storage modules in support of the NASA Advanced Solar Dynamic Brayton Heat Receiver Program. The modules, wedge-shaped canisters containing lithium fluoride (LiF), were designed to minimize the mechanical stresses that occur during the phase change of the LiF. Nickel foam inserts were placed in two of the test canisters to provide thermal conductivity enhancement and to distribute the void volume throughout the canister. A procedure was developed for reducing the nickel oxides on the nickel foam to enhance the wicking ability of the foam. The canisters were filled with LiF and closure-welded at the NASA Lewis Research Center. Two canisters, one with a nickel foam insert, the other without an insert, were thermally cycled in various orientations in a fluidized bed furnace. Computer-aided tomography was successfully used to nondestructively determine void locations in the canisters. Finally, canister dimensional stability was measured after thermal cycling with an inspection fixture.

  10. Clinical review: The Israeli experience: conventional terrorism and critical care

    PubMed Central

    Aschkenasy-Steuer, Gabriella; Shamir, Micha; Rivkind, Avraham; Mosheiff, Rami; Shushan, Yigal; Rosenthal, Guy; Mintz, Yoav; Weissman, Charles; Sprung, Charles L; Weiss, Yoram G

    2005-01-01

    Over the past four years there have been 93 multiple-casualty terrorist attacks in Israel, 33 of them in Jerusalem. The Hadassah-Hebrew University Medical Center is the only Level I trauma center in Jerusalem and has therefore gained important experience in caring for critically injured patients. To do so we have developed a highly flexible operational system for managing the general intensive care unit (GICU). The focus of this review will be on the organizational steps needed to provide operational flexibility, emphasizing the importance of forward deployment of intensive care unit personnel to the trauma bay and emergency room and the existence of a chain of command to limit chaos. A retrospective review of the hospital's response to multiple-casualty terror incidents occurring between 1 October 2000 and 1 September 2004 was performed. Information was assembled from the medical center's trauma registry and from GICU patient admission and discharge records. Patients are described with regard to the severity and type of injury. The organizational work within intensive care is described. Finally, specific issues related to the diagnosis and management of lung, brain, orthopedic and abdominal injuries, caused by bomb blast events associated with shrapnel, are described. This review emphasizes the importance of a multidisciplinary team approach in caring for these patients. PMID:16277738

  11. Experiment to investigate anti. nu. /sub. mu. /. -->. anti. nu. /sub e/ oscillations at Los Alamos Meson Physics Facility

    SciTech Connect

    Kruse, H.W.; Toevs, J.W.

    1981-01-01

    An experiment, being planned at LAMPF, aims to investigate a possible neutrino oscillation channel, anti ..nu../sub ..mu../ ..-->.. anti ..nu../sub e/. If anti ..nu../sub ..mu../, produced in the LAMPF beam stop, oscillate to anti ..nu../sub e/, then interactions anti ..nu../sub e/ + p ..-->.. e/sup +/ + n, may be detected. A large volume liquid scintillator (4470 liter) emplaced at 33 m from the beam stop, detects e/sup +/ and n, after moderation in the hydrogenous liquid and capture in Gd, loaded into the scintillator. Our anticipated signal rate is currently estimated at 1.67 (sigma m/sup 2/)/sup 2//day assuming full amplitude oscillation. The corresponding counting rate, assuming all anti ..nu../sub ..mu../ have oscillated to anti ..nu../sub e/ at the detector is 1.5/day. Cosmic rates are estimated at 0.033/day. Correlated backgrounds from the beam stop are calculated to be small in comparison to cosmic events, except for reactions of ..nu../sub e/ in Pb. These reactions may be reduced with an Fe shield within the detector. With the above rate, a limit on the sensitivity of our experiment for the value of sigma m/sup 2/ is estimated at 0.12 eV/sup 2/ with 70 days of counting. Detector features, estimated background rates, and sensitivity values are discussed.

  12. Stockpile Stewardship: Los Alamos

    SciTech Connect

    McMillan, Charlie; Morgan, Nathanial; Goorley, Tom; Merrill, Frank; Funk, Dave; Korzekwa, Deniece; Laintz, Ken

    2012-01-26

    "Heritage of Science" is a short video that highlights the Stockpile Stewardship program at Los Alamos National Laboratory. Stockpile Stewardship was conceived in the early 1990s as a national science-based program that could assure the safety, security, and effectiveness of the U.S. nuclear deterrent without the need for full-scale underground nuclear testing. This video was produced by Los Alamos National Laboratory for screening at the Lab's Bradbury Science Museum in Los Alamos, NM and is narrated by science correspondent Miles O'Brien.

  13. Stockpile Stewardship: Los Alamos

    ScienceCinema

    McMillan, Charlie; Morgan, Nathanial; Goorley, Tom; Merrill, Frank; Funk, Dave; Korzekwa, Deniece; Laintz, Ken

    2016-07-12

    "Heritage of Science" is a short video that highlights the Stockpile Stewardship program at Los Alamos National Laboratory. Stockpile Stewardship was conceived in the early 1990s as a national science-based program that could assure the safety, security, and effectiveness of the U.S. nuclear deterrent without the need for full-scale underground nuclear testing. This video was produced by Los Alamos National Laboratory for screening at the Lab's Bradbury Science Museum in Los Alamos, NM and is narrated by science correspondent Miles O'Brien.

  14. Proceedings of the Nuclear Criticality Technology and Safety Project Workshop

    SciTech Connect

    Sanchez, R.G.

    1994-01-01

    This report is the proceedings of the annual Nuclear Criticality Technology and Safety Project (NCTSP) Workshop held in Monterey, California, on April 16--28, 1993. The NCTSP was sponsored by the Department of Energy and organized by the Los Alamos Critical Experiments Facility. The report is divided into six sections reflecting the sessions outlined on the workshop agenda.

  15. Examining the Immigrant Experience: Helping Teachers Develop as Critical Educators

    ERIC Educational Resources Information Center

    DeMulder, Elizabeth K.; Stribling, Stacia M.; Day, Monimalika

    2014-01-01

    The purpose of this qualitative case study was to examine ways that a multicultural perspective using critical literacy practices engaged practicing teachers to rethink and re-vision oppressive hegemonic structures and attitudes regarding immigrant students and their families and helped them to develop as critical educators. In the context of a…

  16. Critical Pedagogy: EFL Teachers' Views, Experience and Academic Degrees

    ERIC Educational Resources Information Center

    Mahmoodarabi, Mahsa; Khodabakhsh, Mohammad Reza

    2015-01-01

    Although critical pedagogy has brought about positive changes in the field of education by shifting from traditional pedagogy to emancipatory pedagogy, not much attention has been paid to the factors affecting teachers' beliefs of critical pedagogy and only few studies have been conducted to design reliable and valid instruments to study EFL…

  17. DETERMINISTIC TRANSPORT METHODS AND CODES AT LOS ALAMOS

    SciTech Connect

    J. E. MOREL

    1999-06-01

    The purposes of this paper are to: Present a brief history of deterministic transport methods development at Los Alamos National Laboratory from the 1950's to the present; Discuss the current status and capabilities of deterministic transport codes at Los Alamos; and Discuss future transport needs and possible future research directions. Our discussion of methods research necessarily includes only a small fraction of the total research actually done. The works that have been included represent a very subjective choice on the part of the author that was strongly influenced by his personal knowledge and experience. The remainder of this paper is organized in four sections: the first relates to deterministic methods research performed at Los Alamos, the second relates to production codes developed at Los Alamos, the third relates to the current status of transport codes at Los Alamos, and the fourth relates to future research directions at Los Alamos.

  18. In Situ Observations of an Ionospheric Critical Velocity Experiment

    NASA Astrophysics Data System (ADS)

    Swenson, Charles Merrill

    1992-01-01

    The critical ionization velocity effect (CIV), proposed by Hannes Alfven, may play a major role in the formation, shaping, and distribution of matter in the universe. It is a mechanism whereby the kinetic energy of a neutral cloud relative to a magnetized plasma is used for self -ionization of the neutral cloud. The magnetized plasma through which the neutral cloud passes acts as a type of catalyst, promoting a reaction that would not otherwise occur. For the past 30 years the question of whether a magnetized plasma can act as such a catalyst for the ionization of a streaming gas has been studied in the laboratory where the basic concept has been proven correct. In this thesis we report on a set of rocket borne CIV experiments, CRIT I & II, which were conducted in the ionosphere with barium. We present measurements of the plasma density, electric fields, magnetic fields, energetic electrons, and energetic ions within the ionizing barium stream. Plasma density enhancements were observed and are shown to be signatures of a CIV process albeit one which is less efficient than theory suggests. Other signatures of CIV such as scattering and slowing of the newly created barium ions, heating of electrons, and the emission of an Alfven waves from the ionization region were also detected. We have found that waves within the region where CIV is active are not the classical lower hybrid waves as predicted by current theories. Since waves of some sort are required by all conceivable theories linking the beam energy to the electron gas, this result is quite important. Instead we find a low-frequency long-wavelength mode that is in resonance with the barium ion beam (omega ~ vec k cdotvec V_{ rm beam}). Through an interferometric analysis of the electric field data we show that the wave vector vec k of these waves is aligned with the barium beam (57^circ to vec B_0) while the electric field of the waves is almost perpendicular to vec B_0. Therefore, the wave appears to be a mixed

  19. Los Alamos Science: Number 16

    SciTech Connect

    Cooper, N.G.

    1988-01-01

    It was an unusually stimulating day and a half at Los Alamos when two Nobel Laureates in physiology, a leading paleontologist, and a leading bio-astrophysicist came together to discuss ''Unsolved Problems in the Science of Life,'' the topic of the second in a series of special meetings sponsored by the Fellows of the Laboratory. Just like the first one on ''Creativity in Science,'' this colloquium took us into a broader arena of ideas and viewpoints than is our usual daily fare. To contemplate the evolution and mysteries of intelligent life from the speakers' diverse points of view at one time, in one place was indeed a rare experience.

  20. Critical and Creative Thinking Nexus: Learning Experiences of Doctoral Students

    ERIC Educational Resources Information Center

    Brodin, Eva M.

    2016-01-01

    Critical and creative thinking constitute important learning outcomes at doctoral level across the world. While the literature on doctoral education illuminates this matter through the lens of experienced senior researchers, the doctoral students' own perspective is missing. Based upon interviews with 14 doctoral students from four disciplines at…

  1. Effects of Diversity Experiences on Critical Thinking Skills: Who Benefits?

    ERIC Educational Resources Information Center

    Loes, Chad; Pascarella, Ernest; Umbach, Paul

    2012-01-01

    This study analyzed data from the Wabash National Study of Liberal Arts Education to estimate the unique effects of exposure to classroom diversity and involvement in interactional diversity on growth in critical thinking skills during the first year of college. Net of important confounding influences, neither classroom nor interactional diversity…

  2. Learning Experiences to Develop Critical Thinking through Understanding by Design

    ERIC Educational Resources Information Center

    Williams, David; Williams, Margot

    2009-01-01

    In some classrooms, gifted students are not exposed to the large and complex body of information and knowledge available today; instead, they are limited to what is deemed appropriate for the majority of their classmates. As a result, capable bright students may not develop the critical thinking skills necessary to analyze, synthesize, and…

  3. Learning to Think Critically: A Visual Art Experiment

    ERIC Educational Resources Information Center

    Bowen, Daniel H.; Greene, Jay P.; Kisida, Brian

    2014-01-01

    This article examines whether exposure to the arts has an effect on the ability of students to engage in critical thinking. We conduct a randomized controlled trial involving 3,811 students who were assigned by lottery to participate in a School Visit Program at the newly opened Crystal Bridges Museum of American Art. Students who participated in…

  4. Critical Investigations into Interns' Urban Teaching Apprenticeship Experiences

    ERIC Educational Resources Information Center

    Lockhart, John

    2009-01-01

    A critical task for public school teachers is to build and maintain productive relationships with their students, especially to facilitate learning. That task is particularly important in preparing new teachers for urban schools because cultural differences between the majority of urban teachers and their students can complicate and impair those…

  5. Facilitating Students' Critical Thinking in Online Discussion: An Instructor's Experience

    ERIC Educational Resources Information Center

    Bai, Hua

    2009-01-01

    This paper reported using the practical inquiry model as discourse guide to facilitate students' critical thinking in online discussion. It was found that almost all the postings of the students who had no knowledge of the inquiry model fell into exploration phase except three postings in triggering events phase and two in integration phase. In…

  6. Critical Incidents in Multicultural Supervision: Exploring Supervisees' and Supervisors' Experiences

    ERIC Educational Resources Information Center

    Toporek, Rebecca L.; Ortega-Villalobos, Lideth; Pope-Davis, Donald B.

    2004-01-01

    Reports of supervisors' and supervisees' critical incidents in multicultural supervision were used to (a) explore events in supervision that influenced supervisees' multicultural competence, (b) explore how supervision was experienced differently by supervisors and supervisees, and (c) identify recommendations for improving multicultural…

  7. Experiences of Latino Couples in Relationship Education: A Critical Analysis

    ERIC Educational Resources Information Center

    Perez, Carlos; Brown, Matthew D.; Whiting, Jason B.; Harris, Steven M.

    2013-01-01

    There exists a need to better understand the applicability of Marriage and Relationship Education (MRE) initiatives with diverse populations. This study presents findings from focus groups with Latino men and women (N = 16) who participated in MRE classes. A critical theory approach guided the researchers who used grounded theory methodology to…

  8. Feasibility of Electrostriction for Measurement of the Critical Temperature in the Critical Viscosity Experiment

    NASA Technical Reports Server (NTRS)

    Berg, Robert F.; Moldover, Michael R.

    1993-01-01

    The large compressibility of a pure fluid near its critical point is a potential means of measuring the critical temperature. At the suggestion of Prof. Ferrell we observed electrostriction in xenon by applying a large voltage across a small, open capacitor immersed in the sample and then measuring the capacitance change caused by the subsequent increase in the xenon's local density. This scheme was attractive because the compressibility is a large, well-understood effect and because we were already familiar with low-voltage capacitance measurements. We found qualitative agreement with our initial expectations based on the fluid's compressibility. However, we also found an additional effect comparable in size to the expected electrostriction but proportional to the applied voltage. We have no explanation for this effect. Thus, given the Science Panel's recommendation against investing extensive effort in this direction, we are abandoning further development of an alternate means for measuring the critical temperature.

  9. The Experiences of Neophyte Teachers: A Critical Constructivist Assessment.

    ERIC Educational Resources Information Center

    Goddard, J. Tim; Foster, Rosemary Y.

    2001-01-01

    Interviewed beginning teachers to examine their experiences and the extent to which their preservice programs adequately prepared them for teaching. Results revealed six conceptual and temporal states through which they passed during their initial experiences: archetype; approaching the gates; clearing the gates; the gloss wears off;…

  10. Los Alamos offers Fellowships

    NASA Astrophysics Data System (ADS)

    Los Alamos National Laboratory in New Mexico is calling for applications for postdoctoral appointments and research fellowships. The positions are available in geoscience as well as other scientific disciplines.The laboratory, which is operated by the University of California for the Department of Energy, awards J. Robert Oppenheimer Research Fellowships to scientists that either have or will soon complete doctoral degrees. The appointments are for two years, are renewable for a third year, and carry a stipend of $51,865 per year. Potential applicants should send a resume or employment application and a statement of research goals to Carol M. Rich, Div. 89, Human Resources Development Division, MS P290, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 by mid-November.

  11. Brief Summary of Unreflected and Unmoderated Cylindrical Critical Experiments with Oralloy at Oak Ridge

    SciTech Connect

    Mihalczo, J.T.

    1999-12-08

    This report lists and briefly describes {approx}50 critical and {approx}20 subcritical experiments with unreflected and unmoderated uranium (93.2 wt% {sup 235}U) metal that could easily be incorporated into the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Photographs of several assemblies are included.

  12. Brief summary of unreflected and unmoderated cylindrical critical experiments with oralloy at Oak Ridge

    SciTech Connect

    Mihalczo, J.T.

    1999-11-01

    This report lists and briefly describes {approximately}50 critical and {approximately}20 subcritical experiments with unreflected and unmoderated uranium (93.2 wt% {sup 235}U) metal that could easily be incorporated into the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Photographs of several assemblies are included.

  13. The Los Alamos primer

    SciTech Connect

    Serber, R.

    1992-01-01

    This book contains the 1943 lecture notes of Robert Serber. Serber was a protege of J. Robert Oppenheimer and member of the team that built the first atomic bomb - reveal what the Los Alamos scientists knew, and did not know, about the terrifying weapon they were building.

  14. The unclosed circle: Los Alamos and the human and environmental legacy of the atom, 1943--1963

    NASA Astrophysics Data System (ADS)

    Hughes, Scott Daniel

    2000-12-01

    This dissertation examines the application of nuclear technology at Los Alamos Scientific Laboratory and the legacy this technology wrought on humans and the environment during the period from 1943 to 1963. Through a focus directed primarily on the Health Division, the study considers various dimensions of the Los Alamos Laboratory including radioactive waste management, human subject experimentation, and nuclear weapons testing. Since its inception in 1943, Los Alamos has held a central role in the research and development of nuclear weapons for the United States. In relation to this central mission, the Laboratory produced various types of radioactive wastes, conducted human subject experiments, and participated in hundreds of nuclear weapons tests. All of these functions resulted in a myriad legacy of human and environmental effects whose consequences have not yet been fully assessed. This investigation, using primary, secondary, and recently declassified documents, discusses the development of nuclear physics and radiological health practices in the half-century prior to World War Two and the American reactions in the realms of science and politics to the news concerning nuclear fission. It then moves to a discussion of the emergence of Los Alamos and analyzes how personnel addressed the attendant hazards of nuclear technology and some of the implications of these past practices. Furthermore, the dissertation discusses human subject experimentation conducted at Los Alamos. The final part of the study investigates the multiple roles played by Los Alamos personnel in the testing of nuclear weapons, the attempts to understand and minimize the hazards of such testing, and the Ra-La sub-critical detonations conducted within the geographical boundaries at the Laboratory between 1943-1963. By focusing on a long-neglected part of the American West. Cold War Los Alamos, this dissertation will contribute to the study of the effects that both World War Two and the Cold

  15. Los Alamos Explosives Performance Key to Stockpile Stewardship

    SciTech Connect

    Dattelbaum, Dana

    2014-11-03

    As the U.S. Nuclear Deterrent ages, one essential factor in making sure that the weapons will continue to perform as designed is understanding the fundamental properties of the high explosives that are part of a nuclear weapons system. As nuclear weapons go through life extension programs, some changes may be advantageous, particularly through the addition of what are known as "insensitive" high explosives that are much less likely to accidentally detonate than the already very safe "conventional" high explosives that are used in most weapons. At Los Alamos National Laboratory explosives research includes a wide variety of both large- and small-scale experiments that include small contained detonations, gas and powder gun firings, larger outdoor detonations, large-scale hydrodynamic tests, and at the Nevada Nuclear Security Site, underground sub-critical experiments.

  16. Los Alamos Explosives Performance Key to Stockpile Stewardship

    ScienceCinema

    Dattelbaum, Dana

    2016-07-12

    As the U.S. Nuclear Deterrent ages, one essential factor in making sure that the weapons will continue to perform as designed is understanding the fundamental properties of the high explosives that are part of a nuclear weapons system. As nuclear weapons go through life extension programs, some changes may be advantageous, particularly through the addition of what are known as "insensitive" high explosives that are much less likely to accidentally detonate than the already very safe "conventional" high explosives that are used in most weapons. At Los Alamos National Laboratory explosives research includes a wide variety of both large- and small-scale experiments that include small contained detonations, gas and powder gun firings, larger outdoor detonations, large-scale hydrodynamic tests, and at the Nevada Nuclear Security Site, underground sub-critical experiments.

  17. Historic Manhattan Project Sites at Los Alamos

    SciTech Connect

    McGehee, Ellen

    2014-05-22

    The Manhattan Project laboratory constructed at Los Alamos, New Mexico, beginning in 1943, was intended from the start to be temporary and to go up with amazing speed. Because most of those WWII-era facilities were built with minimal materials and so quickly, much of the original infrastructure was torn down in the late '40s and early '50s and replaced by more permanent facilities. However, a few key facilities remained, and are being preserved and maintained for historic significance. Four such sites are visited briefly in this video, taking viewers to V-Site, the buildings where the first nuclear explosive device was pre-assembled in preparation for the Trinity Test in Southern New Mexico. Included is another WWII area, Gun Site. So named because it was the area where scientists and engineers tested the so-called "gun method" of assembling nuclear materials -- the fundamental design of the Little Boy weapon that was eventually dropped on Hiroshima. The video also goes to Pajarito Site, home of the "Slotin Building" and "Pond Cabin." The Slotin Building is the place where scientist Louis Slotin conducted a criticality experiment that went awry in early 1946, leading to his unfortunate death, and the Pond Cabin served the team of eminent scientist Emilio Segre who did early chemistry work on plutonium that ultimately led to the Fat Man weapon.

  18. Historic Manhattan Project Sites at Los Alamos

    ScienceCinema

    McGehee, Ellen

    2016-07-12

    The Manhattan Project laboratory constructed at Los Alamos, New Mexico, beginning in 1943, was intended from the start to be temporary and to go up with amazing speed. Because most of those WWII-era facilities were built with minimal materials and so quickly, much of the original infrastructure was torn down in the late '40s and early '50s and replaced by more permanent facilities. However, a few key facilities remained, and are being preserved and maintained for historic significance. Four such sites are visited briefly in this video, taking viewers to V-Site, the buildings where the first nuclear explosive device was pre-assembled in preparation for the Trinity Test in Southern New Mexico. Included is another WWII area, Gun Site. So named because it was the area where scientists and engineers tested the so-called "gun method" of assembling nuclear materials -- the fundamental design of the Little Boy weapon that was eventually dropped on Hiroshima. The video also goes to Pajarito Site, home of the "Slotin Building" and "Pond Cabin." The Slotin Building is the place where scientist Louis Slotin conducted a criticality experiment that went awry in early 1946, leading to his unfortunate death, and the Pond Cabin served the team of eminent scientist Emilio Segre who did early chemistry work on plutonium that ultimately led to the Fat Man weapon.

  19. Critical care delivery: the experience of a civilian terrorist attack.

    PubMed

    Shirley, P J

    2006-03-01

    It has been recognised for some time that a terrorist incident was threatened in the U.K. and it has been noted previously in the JRAMC that the locations for terrorist atrocities are likely to be more diverse than previously experienced. July 7th 2005 witnessed the first terrorist suicide bombing on the U.K. mainland, targeting the public transport system in London. These attacks were unprecedented in both scale and intensity but they were anticipated in London. However there were clear difficulties, relating to multiple sites, their location underground and early problems with communication (2). This article highlights some of the experiences and learning points of the Intensive Care Medicine Service at the Royal London Hospital (RLH) in the wake of the July 7th bombings. The RLH was the single biggest receiver of casualties (195); seven of whom were admitted to the Intensive Care Unit. The Defence Medical Services have tri-service representation (both regular and reserve) at the RLH in Emergency Medicine and Pre-hospital Care, Surgical Services and Intensive Care Medicine.

  20. Turning Experiences into Critical Re?ections: Examples from Taiwanese In-Service Teachers

    ERIC Educational Resources Information Center

    Chi, Feng-ming

    2013-01-01

    The aims of this paper are twofold: to investigate how Taiwanese teachers of English as a Foreign Language turned experiences into critical reflections via journal writings and to describe how they gauged critical reflections as teaching inquiry. The participants were 12 Taiwanese in-service teachers enrolled in an elective course entitled "Doing…

  1. Analysis of Fresh Fuel Critical Experiments Appropriate for Burnup Credit Validation

    SciTech Connect

    DeHart, M.D.

    1995-01-01

    The ANS/ANS-8.1 standard requires that calculational methods used in determining criticality safety limits for applications outside reactors be validated by comparison with appropriate critical experiments. This report provides a detailed description of 34 fresh fuel critical experiments and their analyses using the SCALE-4.2 code system and the 27-group ENDF/B-IV cross-section library. The 34 critical experiments were selected based on geometry, material, and neutron interaction characteristics that are applicable to a transportation cask loaded with pressurized-water-reactor spent fuel. These 34 experiments are a representative subset of a much larger data base of low-enriched uranium and mixed-oxide critical experiments. A statistical approach is described and used to obtain an estimate of the bias and uncertainty in the calculational methods and to predict a confidence limit for a calculated neutron multiplication factor. The SCALE-4.2 results for a superset of approximately 100 criticals are included in uncertainty analyses, but descriptions of the individual criticals are not included.

  2. Cryogenic design of the liquid helium experiment ``critical dynamics in microgravity``

    SciTech Connect

    Moeur, W.A.; Adriaans, M.J.; Boyd, S.T.; Strayer, D.M.; Duncan, R.V. |

    1995-10-01

    Although many well controlled experiments have been conducted to measure the static properties of systems near criticality, few experiments have explored the transport properties in systems driven far away from equilibrium as a phase transition occurs. The cryogenic design of an experiment to study the dynamic aspect of critical phenomena is reported here. Measurements of the thermal gradient across the superfluid (He II) -- normal fluid (He I) interface in helium under microgravity conditions will be performed as a heat flux holds the system away from equilibrium. New technologies are under development for this experiment, which is in the definition phase for a space shuttle flight.

  3. Bibliography for nuclear criticality accident experience, alarm systems, and emergency management

    SciTech Connect

    Putman, V.L.

    1995-09-01

    The characteristics, detection, and emergency management of nuclear criticality accidents outside reactors has been an important component of criticality safety for as long as the need for this specialized safety discipline has been recognized. The general interest and importance of such topics receives special emphasis because of the potentially lethal, albeit highly localized, effects of criticality accidents and because of heightened public and regulatory concerns for any undesirable event in nuclear and radiological fields. This bibliography lists references which are potentially applicable to or interesting for criticality alarm, detection, and warning systems; criticality accident emergency management; and their associated programs. The lists are annotated to assist bibliography users in identifying applicable: industry and regulatory guidance and requirements, with historical development information and comments; criticality accident characteristics, consequences, experiences, and responses; hazard-, risk-, or safety-analysis criteria; CAS design and qualification criteria; CAS calibration, maintenance, repair, and testing criteria; experiences of CAS designers and maintainers; criticality accident emergency management (planning, preparedness, response, and recovery) requirements and guidance; criticality accident emergency management experience, plans, and techniques; methods and tools for analysis; and additional bibliographies.

  4. Validation studies based on critical experiments performed with fuel pin arrays moderated by Pu + U solutions

    SciTech Connect

    Smolen, G.R.; Matsumoto, T. )

    1989-01-01

    This paper outlines the results of a calculational study that was performed to validate the SCALE computer code system using data from critical experiments performed with fuel pin arrays moderated by mixed Pu + U aqueous solutions. A companion paper describes the experiments and discusses the criticality data that were obtained. These experimental activities are part of a joint exchange program between the US Department of Energy (DOE) and the Power Reactor and Nuclear Fuel Development Corporation of Japan in the area of criticality data development. The Consolidated fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) manages the program for the DOE. The experiments were conducted at the Battelle Pacific Northwest Laboratories-Critical Mass Laboratory (PNL-CML).

  5. Critical experiments on low-enriched uranium oxide systems with H/U = 2. 03

    SciTech Connect

    Rothe, R E; Goebel, G R

    1982-02-01

    Seven critical experiments were performed on a horizontal split table machine using 4.48% enriched /sup 235/U uranium oxide (U/sub 3/O/sub 8/). The oxide was compacted to a density of 4.68 g/cm/sup 3/ and placed in 152-mm cubical aluminum cans. Water was added to achieve an H/U atomic ratio of 2.03. Various arrays of oxide cans were distributed on each half of the split table and the separation between halves reduced until criticality occurred. The critical table separation varied from 4.3 mm to 29.3 mm. These experiments were performed in both plastic and concrete reflectors. The first five experiments required the addition of a high-enriched (approx. 93% /sup 235/U) metal driver to achieve criticality. Critical uranium driver masses ranged from 2.765 kg to 13.730 kg for 5 x 5 x 5 arrays of uranium oxide cans. In all five cases, the center can of the array was deleted to accommodate the driver. The uranium oxide mass was 1859.6 kg. Two additional experiments in the plastic reflector contained either 9.3-mm- or 24.3-mm-thick plastic moderator material between the oxide cans. These latter experiments did not require a driver to achieve criticality; and the uranium oxide mass was 723.9 kg for the configuration having the thinner interstitial moderator and 452.4 kg for the other.

  6. Science Requirements for a Space Flight Experiment Entitled Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    Berg, Robert F.; Moldover, Michael R.

    1993-01-01

    We propose to measure in low gravity the viscosity of xenon close to its critical point. The accuracy will be sufficient to eliminate uncertainties currently associated with the analysis of l-g experiments. The measurements will provide the first direct observation of the predicted power-law divergence of viscosity in a pure fluid. The measurements will also strengthen Zeno's test of mode coupling theory by greatly increasing the reliability of the extrapolation of viscosity to low reduced temperatures. Our scientific objectives are described in more detail in one of the attached reports. The low-gravity experiment will be the final stage of a program whose completed ground-based stages are: (1) theoretical studies by one of the principal investigators (MRM) and coworkers, (2) critical viscosity measurements of binary liquid mixtures, (3) critical viscosity measurements of pure fluids in l-g, and development of a suitable vibration-insensitive viscometer. Our technical approach is described in the draft Science Requirements Document. One of us (MRM) has reviewed opportunities for critical phenomena research in low gravity. Both of us were co-principal investigators in the Thermal Equilibration Experiment in the Critical Point Facility, flown on IML-1 in 1992. From this experience, and from the technical maturity of our ground-based work, we believe our critical point viscometer is ready for development as a flight experiment.

  7. Simulated and Virtual Science Laboratory Experiments: Improving Critical Thinking and Higher-Order Learning Skills

    ERIC Educational Resources Information Center

    Simon, Nicole A.

    2013-01-01

    Virtual laboratory experiments using interactive computer simulations are not being employed as viable alternatives to laboratory science curriculum at extensive enough rates within higher education. Rote traditional lab experiments are currently the norm and are not addressing inquiry, Critical Thinking, and cognition throughout the laboratory…

  8. Benchmark Evaluation of the Medium-Power Reactor Experiment Program Critical Configurations

    SciTech Connect

    Margaret A. Marshall; John D. Bess

    2013-02-01

    A series of small, compact critical assembly (SCCA) experiments were performed in 1962-1965 at the Oak Ridge National Laboratory Critical Experiments Facility (ORCEF) for the Medium-Power Reactor Experiment (MPRE) program. The MPRE was a stainless-steel clad, highly enriched uranium (HEU)-O2 fuelled, BeO reflected reactor design to provide electrical power to space vehicles. Cooling and heat transfer were to be achieved by boiling potassium in the reactor core and passing vapor directly through a turbine. Graphite- and beryllium-reflected assemblies were constructed at ORCEF to verify the critical mass, power distribution, and other reactor physics measurements needed to validate reactor calculations and reactor physics methods. The experimental series was broken into three parts, with the third portion of the experiments representing the beryllium-reflected measurements. The latter experiments are of interest for validating current reactor design efforts for a fission surface power reactor. The entire series has been evaluated as acceptable benchmark experiments and submitted for publication in the International Handbook of Evaluated Criticality Safety Benchmark Experiments and in the International Handbook of Evaluated Reactor Physics Benchmark Experiments.

  9. Nuclear Forensics at Los Alamos National Laboratory

    SciTech Connect

    Podlesak, David W; Steiner, Robert E.; Burns, Carol J.; LaMont, Stephen P.; Tandon, Lav

    2012-08-09

    The overview of this presentation is: (1) Introduction to nonproliferation efforts; (2) Scope of activities at Los Alamos National Laboratory; (3) Facilities for radioanalytical work at LANL; (4) Radiochemical characterization capabilities; and (5) Bulk chemical and materials analysis capabilities. Some conclusions are: (1) Analytical chemistry measurements on plutonium and uranium matrices are critical to numerous defense and non-defense programs including safeguards accountancy verification measurements; (2) Los Alamos National Laboratory operates capable actinide analytical chemistry and material science laboratories suitable for nuclear material forensic characterization; (3) Actinide analytical chemistry uses numerous means to validate and independently verify that measurement data quality objectives are met; and (4) Numerous LANL nuclear facilities support the nuclear material handling, preparation, and analysis capabilities necessary to evaluate samples containing nearly any mass of an actinide (attogram to kilogram levels).

  10. Criticality measurements for SNM accountability

    SciTech Connect

    Bohman, J.; Martin, E.R.; Butterfield, K.; Paternoster, R.

    1998-03-01

    Based on extensive operating experience with the Godiva IV fast metal burst assembly at Los Alamos National Laboratory, the authors were able to create data plots for reactivity worths of standard configurations at various temperatures and room return locations. These plots show that the material uncertainties in criticality measurements are within {+-} 20 grams out of the 65.4 kilogram HEU Godiva core. This is superior to active neutron well coincidence counter (AWCC) measurements. The criticality measurements have the additional advantage of not requiring disassembly of the reactor. No disassembly means the measurement takes less time--it can be done during each operation--and there is less dose to measurement personnel.

  11. The metaphor of experience and the experience of metaphor: critical reflection on a contemplative process toward aliveness and compassion.

    PubMed

    Kuchan, Karen L

    2009-01-01

    An epistemological web invites critical reflection and the possibility of new ideas emerging in the space between experience and different ways of thinking. A web offers a postmodern method of a hermeneutic of experience and a way of knowing that creates space for a robust, flexible, dynamic process of critical reflection and discovery. The following article utilizes an inter-textual epistemological web (see Figure 1, p. 4) to answer the question, "Do metaphors of experience and experiences of metaphor during contemplative healing prayer with a spiritual director nurture a transformational process toward aliveness and compassion?" How can one discover and communicate this reality in dialog with Hebrew scripture, psychoanalytic theory, affective neuroscience and ways of thinking about contemplative transformation?

  12. Maternal critical care: what can we learn from patient experience? A qualitative study

    PubMed Central

    Hinton, Lisa; Locock, Louise; Knight, Marian

    2015-01-01

    Objective For every maternal death, nine women develop severe maternal morbidity. Many of those women will need care in an intensive care unit (ICU) or high dependency unit (HDU). Critical care in the context of pregnancy poses distinct issues for staff and patients, for example, with breastfeeding support and separation from the newborn. This study aimed to understand the experiences of women who experience a maternal near miss and require critical care after childbirth. Setting Women and some partners from across the UK were interviewed as part of a study of experiences of near-miss maternal morbidity. Design A qualitative study, using semistructured interviews. Participants A maximum variation sample was recruited of 35 women and 11 partners of women who had experienced a severe maternal illness, which without urgent medical attention would have led to her death. 18 of the women were admitted to ICU or HDU. Results The findings are presented in three themes: being in critical care; being a new mother in critical care; transfer and follow-up after critical care. The study highlights the shock of requiring critical care for new mothers and the gulf between their expectations of birth and what actually happened; the devastation of being separated from their baby, how valuable access to their newborn was, if possible, and the importance of breast feeding; the difficulties of transfer and the need for more support; the value of follow-up and outreach to this population of critical care patients. Conclusions While uncommon, critical illness in pregnancy can be devastating for new mothers and presents a challenge for critical care and maternity staff. This study provides insights into these challenges and recommendations for overcoming them drawn from patient experiences. PMID:25916486

  13. Criticality experiments with planar arrays of three-liter bottles containing plutonium nitrate solution

    SciTech Connect

    Durst, B.M.; Clayton, E.D.; Smith, J.H.

    1985-01-01

    The objective of these experiments was to provide benchmark data to validate calculational codes used in critically safety assessments of plant configurations. Arrays containing up to as many as sixteen three-liter bottles filled with plutonium nitrate were used in the experiments. A split-table device was used in the final assembly of the arrays. Ths planar arrays were reflected with close fitting plexiglas on each side and on the bottom but not the top surface. The experiments addressed a number of factors effecting criticality: the critical air gap between bottles in an array of fixed number of bottles, the number of bottles required for criticality if the bottles were touching, and the effect on critical array spacing and critical bottle number due to the insertion of an hydrogeneous substance into the air gap between bottles. Each bottle contained about 2.4l of Pu(NO{sub 3}){sub 4} solution at a Pu concentration of 105g Pu/l, with the {sup 240}Pu content being 2.9 wt% at a free acid molarity H{sup +} of 5.1. After the initial series of experiments were performed with bottles separated by air gaps, plexiglas shells of varying thicknesses were placed around each bottle to investigate how moderation between bottles affects both the number of bottles required for criticality and the critical spacing between each bottle. The minimum of bottles required for criticality was found to be 10.9 bottles, occurring for a square array with bottles in contact. As the bottles were spaced apart, the critical number increased. For sixteen bottles in a square array, the critical separation between surfaces in both x and y direction was 0.96 cm. The addition of plexiglas around each bottle decreased the critical bottle number, compared to those separated in air, but the critical bottle number, even with interstitial plastic in place was always greater than 10.9 bottles. The most reactive configuration was a tightly packed array of bottles with no intervening material.

  14. Solution High-Energy Burst Assembly (SHEBA) results from subprompt critical experiments with uranyl fluoride fuel

    SciTech Connect

    Cappiello, C.C.; Butterfield, K.B.; Sanchez, R.G.; Bounds, J.A.; Kimpland, R.H.; Damjanovich, R.P.; Jaegers, P.J.

    1997-08-01

    Experiments were performed to measure a variety of parameters for SHEBA: behavior of the facility during transient and steady-state operation; characteristics of the SHEBA fuel; delayed-critical solution height vs solution temperature; initial reactor period and reactivity vs solution height; calibration of power level vs reactor power instrumentation readings; flux profile in SHEBA; radiation levels and neutron spectra outside the assembly for code verification and criticality alarm and dosimetry purposes; and effect on reactivity of voids in the fuel.

  15. Evaluation of Plutonium Hemisphere Critical Experiments Partially Reflected by Steel and Oil

    SciTech Connect

    John D. Bess

    2012-01-01

    A series of 15 critical experiments performed at the Rocky Flats Critical Mass Laboratory in the late 1960s were evaluated and then determined to represent acceptable benchmark experiments for the validation of calculational methods. This series of experiments was part of a larger set of experiments performed to evaluate operational safety margins at the Rocky Flats Plant. The experiments consisted of bare plutonium metal hemishells reflected by steel hemishells of increasing thickness and motor oil. The hemishell assembly was suspended within dual aluminum tanks. Criticality was achieved by pumping oil into the tanks such that effectively infinite reflection was achieved in all directions except directly above the assembly; then the critical oil height was recorded. The results of these experiments had been initially ignored because early computational methods had been inadequate to analyze partially-reflected configurations. The dominant uncertainties include the uncertainty in the average plutonium density and the composition of materials in the gaps between the plutonium hemishells. Simple and detailed benchmark models were developed. Eigenvalue calculations using MCNP5 and ENDF/B-VII.0 were within 2s of the benchmark values. This benchmark evaluation has been added to the ICSBEP Handbook.

  16. Simulated and Virtual Science Laboratory Experiments: Improving Critical Thinking and Higher-Order Learning Skills

    NASA Astrophysics Data System (ADS)

    Simon, Nicole A.

    Virtual laboratory experiments using interactive computer simulations are not being employed as viable alternatives to laboratory science curriculum at extensive enough rates within higher education. Rote traditional lab experiments are currently the norm and are not addressing inquiry, Critical Thinking, and cognition throughout the laboratory experience, linking with educational technologies (Pyatt & Sims, 2007; 2011; Trundle & Bell, 2010). A causal-comparative quantitative study was conducted with 150 learners enrolled at a two-year community college, to determine the effects of simulation laboratory experiments on Higher-Order Learning, Critical Thinking Skills, and Cognitive Load. The treatment population used simulated experiments, while the non-treatment sections performed traditional expository experiments. A comparison was made using the Revised Two-Factor Study Process survey, Motivated Strategies for Learning Questionnaire, and the Scientific Attitude Inventory survey, using a Repeated Measures ANOVA test for treatment or non-treatment. A main effect of simulated laboratory experiments was found for both Higher-Order Learning, [F (1, 148) = 30.32,p = 0.00, eta2 = 0.12] and Critical Thinking Skills, [F (1, 148) = 14.64,p = 0.00, eta 2 = 0.17] such that simulations showed greater increases than traditional experiments. Post-lab treatment group self-reports indicated increased marginal means (+4.86) in Higher-Order Learning and Critical Thinking Skills, compared to the non-treatment group (+4.71). Simulations also improved the scientific skills and mastery of basic scientific subject matter. It is recommended that additional research recognize that learners' Critical Thinking Skills change due to different instructional methodologies that occur throughout a semester.

  17. A short review of critical experiments performed at the Kurchatov Institute

    SciTech Connect

    Gagarinski, A.Yu.; Glushkov, Y.S.; Ponomarev-Stepnoi, N.N.

    1997-06-01

    Since the 1950s, the Institute of Atomic Energy (now the Russian Research Center Kurchatov Institute) has investigated nuclear reactors intended for various purposes. A summary of the present state of these assemblies is given in an attachment to the paper. A second attachment provides a brief description of critical experiments for small nuclear power systems intended for decentralized power generation. The critical assemblies for these experiments were moderated by water and zirconium hydride, and fuel elements ranged in enrichment from 5% to 95% uranium 235. 7 refs.

  18. Experiments on ocular tissue ablation at 5.3 and 6.0 {mu}m with the Los Alamos advanced FEL

    SciTech Connect

    Nguyen, D.C.; Ren, Q.; Hill, R.

    1995-12-31

    We investigated the ablation characteristics of a picosecond free-electron laser and compared its ablation effects on ocular tissues at 5.3 {mu}m and 6.0 {mu}m. The Advanced FEL at Los Alamos, operating in the wavelength range 4-6 {mu}m, was used for this study. The 10-{mu}s macropulse consisted of {approximately}1000 micropulses, each approximately 15 ps in length and separated from one another by 9.2 ns. The FEL beam was passed through a series of attenuator and focused to a 200-{mu}m spot in the sample with a 150-mm f.l. CaF{sub 2} lens. The energy in each macropulse ranged from 5 to 120 mJ. Five transplantable corneal-scleral buttons preserved in corneal storage media were used for this study. The tissue sample was positioned at the focused FEL beam for the ablation, and then fixed for histologic study. Corneal cuts made at 6.0 {mu}m revealed a well-defined ablation boundary. The measured lateral zone of the tissue damage was 11 {+-} 2 {mu}m. The integrity of the adjacent tissue was well maintained. By contrast, the ablation boundary of the corneal cuts made at 5.3 {mu}m appeared to be very disruptive. The collagen fiber near the ablation was thermally denatured and lost its organized structure. The lateral dimension of such effect extended out to 220 {mu}m beyond the intended cut into the surrounding tissues. We concluded that a short-pulsed laser operating at 6 {mu}m may be a potentially effective tool for cutting ocular tissues.

  19. Los Alamos National Laboratory

    SciTech Connect

    Dogliani, Harold O

    2011-01-19

    The purpose of the briefing is to describe general laboratory technical capabilities to be used for various groups such as military cadets or university faculty/students and post docs to recruit into a variety of Los Alamos programs. Discussed are: (1) development and application of high leverage science to enable effeictive, predictable and reliability outcomes; (2) deter, detect, characterize, reverse and prevent the proliferation of weapons of mass destruction and their use by adversaries and terrorists; (3) modeling and simulation to define complex processes, predict outcomes, and develop effective prevention, response, and remediation strategies; (4) energetic materials and hydrodynamic testing to develop materials for precise delivery of focused energy; (5) materials cience focused on fundamental understanding of materials behaviors, their quantum-molecular properties, and their dynamic responses, and (6) bio-science to rapidly detect and characterize pathogens, to develop vaccines and prophylactic remedies, and to develop attribution forensics.

  20. GROWTH OF THE INTERNATIONAL CRITICALITY SAFETY AND REACTOR PHYSICS EXPERIMENT EVALUATION PROJECTS

    SciTech Connect

    J. Blair Briggs; John D. Bess; Jim Gulliford

    2011-09-01

    Since the International Conference on Nuclear Criticality Safety (ICNC) 2007, the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and the International Reactor Physics Experiment Evaluation Project (IRPhEP) have continued to expand their efforts and broaden their scope. Eighteen countries participated on the ICSBEP in 2007. Now, there are 20, with recent contributions from Sweden and Argentina. The IRPhEP has also expanded from eight contributing countries in 2007 to 16 in 2011. Since ICNC 2007, the contents of the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments1' have increased from 442 evaluations (38000 pages), containing benchmark specifications for 3955 critical or subcritical configurations to 516 evaluations (nearly 55000 pages), containing benchmark specifications for 4405 critical or subcritical configurations in the 2010 Edition of the ICSBEP Handbook. The contents of the Handbook have also increased from 21 to 24 criticality-alarm-placement/shielding configurations with multiple dose points for each, and from 20 to 200 configurations categorized as fundamental physics measurements relevant to criticality safety applications. Approximately 25 new evaluations and 150 additional configurations are expected to be added to the 2011 edition of the Handbook. Since ICNC 2007, the contents of the 'International Handbook of Evaluated Reactor Physics Benchmark Experiments2' have increased from 16 different experimental series that were performed at 12 different reactor facilities to 53 experimental series that were performed at 30 different reactor facilities in the 2011 edition of the Handbook. Considerable effort has also been made to improve the functionality of the searchable database, DICE (Database for the International Criticality Benchmark Evaluation Project) and verify the accuracy of the data contained therein. DICE will be discussed in separate papers at ICNC 2011. The status of the ICSBEP and the IRPh

  1. Nuclear criticality safety experiments, calculations, and analyses: 1958 to 1982. Volume 1. Lookup tables

    SciTech Connect

    Koponen, B.L.; Hampel, V.E.

    1982-10-21

    This compilation contains 688 complete summaries of papers on nuclear criticality safety as presented at meetings of the American Nuclear Society (ANS). The selected papers contain criticality parameters for fissile materials derived from experiments and calculations, as well as criticality safety analyses for fissile material processing, transport, and storage. The compilation was developed as a component of the Nuclear Criticality Information System (NCIS) now under development at the Lawrence Livermore National Laboratory. The compilation is presented in two volumes: Volume 1 contains a directory to the ANS Transaction volume and page number where each summary was originally published, the author concordance, and the subject concordance derived from the keyphrases in titles. Volume 2 contains - in chronological order - the full-text summaries, reproduced here by permission of the American Nuclear Society from their Transactions, volumes 1-41.

  2. The Impact of Simulation-Based Learning Experience on Critical Thinking Acquisition

    ERIC Educational Resources Information Center

    Rome, Candice

    2012-01-01

    The purpose of this comparative experimental project was to compare the impact of simulation-based learning experiences to traditional clinical rotations on critical thinking acquisition of associate nursing students within a maternal-child course. Innovative pedagogies have been integrated in nursing programs to augment inadequate clinical…

  3. A Critical Review of Seligman's Laboratory Experiments on Learned Helplessness and Depression in Humans

    ERIC Educational Resources Information Center

    Costello, Charles G.

    1978-01-01

    Six laboratory experiments on learned helplessness and depression in humans reported by Seligman and his colleagues were critically reviewed. A number of methodological and conceptual problems were discussed. Suggests that it is important for psychologists to scrutinize psychological theories in order to assess their conceptual clarity and…

  4. 76 FR 40945 - Rensselaer Polytechnic Institute Critical Experiments Facility; Notice of Issuance of Renewed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-12

    ... Opportunity for Hearing published in the Federal Register on May 15, 2008 (73 FR 28170). The NRC received no... Impact for license renewal, noticed in the Federal Register on June 14, 2011 (76 FR 34770), and concluded... COMMISSION Rensselaer Polytechnic Institute Critical Experiments Facility; Notice of Issuance of...

  5. Using Critical Experiences to Build Understanding of Science Teacher Educators' Pedagogical Knowledge

    ERIC Educational Resources Information Center

    Cooper, Rebecca

    2013-01-01

    The purpose of the reported research was to build understanding of science teacher educators' (STEs') development of pedagogical knowledge (PK) using critical experiences (CEs). It further investigated the role of CEs in developing PK for STEs, the ways that STEs' notions of PK develop and change over their careers, and the…

  6. Critical Race Theory, Disability Microaggressions and Latina/o Student Experiences in Special Education

    ERIC Educational Resources Information Center

    Dávila, Brianne

    2015-01-01

    This research draws upon critical race theory (CRT) to explore the experiences of Latina/o students in special education. It seeks to extend the theoretical construct of racial microaggressions and illustrate the additional layer of disability as I present data that are particular to the context of special education and the assigned label of…

  7. How Do Virtual World Experiences Bring about Learning? A Critical Review of Theories

    ERIC Educational Resources Information Center

    Loke, Swee-Kin

    2015-01-01

    While students do learn real-world knowledge and skills in virtual worlds, educators have yet to adequately theorise how students' virtual world experiences bring about this learning. This paper critically reviewed theories currently used to underpin empirical work in virtual worlds for education. In particular, it evaluated how applicable these…

  8. Development of Critical Thinking through Aesthetic Experience: The Case of Students of an Educational Department

    ERIC Educational Resources Information Center

    Raikou, Natassa

    2016-01-01

    This article addresses an application performed in tertiary education--a department of pedagogical and educational sciences--of a contemporary method, Transformative Learning through Aesthetic Experience. The method is based on the use of art and aims to reinforce and promote the development of critical thinking within educational settings.…

  9. The Experience of Critical Self-Reflection by Life Coaches: A Phenomenological Study

    ERIC Educational Resources Information Center

    Shaw, Deanna Lynn

    2012-01-01

    The purpose of this study was to describe the experience of critical self-reflection by life coaches. Life coaching is expanding within many disciplines including education, health care, business, social work, and wellness. Life coaching involves a coach working with an individual or groups aimed at effecting change for professional and personal…

  10. Safety analysis report for the Hanford Critical Mass Laboratory: Supplement No. 2. Experiments with heterogeneous assemblies

    SciTech Connect

    Gore, B.F.; Davenport, L.C.

    1981-04-01

    Factors affecting the safety of criticality experiments using heterogeneous assemblies are described and assessed. It is concluded that there is no substantial change in safety from experiments already being routinely performed at the Critical Mass Laboratory (CML), and that laboratory and personnel safety are adequately provided by the combination of engineered and administrative safety limits enforced at the CML. This conclusion is based on the analysis of operational controls, potential hazards, and the consequences of accidents. Contingencies considered that could affect nuclear criticality include manual changes in fuel loadings, water flooding, fire, explosion, loss of services, earthquake, windstorm, and flood. Other potential hazards considered include radiation exposure to personnel, and potential releases within the Assembly Room and outside to the environment. It is concluded that the Maximum Credible Nuclear Burst of 3 x 10/sup 18/ fissions (which served as the design basis for the CML) is valid for heterogeneous assemblies as well as homogeneous assemblies. This is based upon examination of the results of reactor destructive tests and the results of the SL-1 reactor destructive accident. The production of blast effects which might jeopardize the CML critical assembly room (of thick reinforced concrete) is not considered credible due to the extreme circumstances required to produce blast effects in reactor destructive tests. Consequently, it is concluded that, for experiments with heterogeneous assemblies, the consequences of the Maximum Credible Burst are unchanged from those previously estimated for experiments with homogeneous systems.

  11. A Critical Reflection on a Suggested Return to Aesthetic Experience in Socialist China

    ERIC Educational Resources Information Center

    Man, Eva Kit Wah

    2001-01-01

    It is said that aestheticians today, including art critics and philosophers, are yearning for some kind of salvation for contemporary art. This salvation would come in the form of a return to aesthetic experience that would act as a foundation enabling resistance to pure discursive reflection and intertextuality. These debates concerning…

  12. Using Compression Isotherms of Phospholipid Monolayers to Explore Critical Phenomena: A Biophysical Chemistry Experiment

    ERIC Educational Resources Information Center

    Gragson, Derek E.; Beaman, Dan; Porter, Rhiannon

    2008-01-01

    Two experiments are described in which students explore phase transitions and critical phenomena by obtaining compression isotherms of phospholipid monolayers using a Langmuir trough. Through relatively simple analysis of their data students gain a better understanding of compression isotherms, the application of the Clapeyron equation, the…

  13. Evaluation of Fission Product Critical Experiments and Associated Biases for Burnup Credit Validation

    SciTech Connect

    Mueller, Don; Rearden, Bradley T; Reed, Davis Allan

    2010-01-01

    One of the challenges associated with implementation of burnup credit is the validation of criticality calculations used in the safety evaluation; in particular the availability and use of applicable critical experiment data. The purpose of the validation is to quantify the relationship between reality and calculated results. Validation and determination of bias and bias uncertainty require the identification of sets of critical experiments that are similar to the criticality safety models. A principal challenge for crediting fission products (FP) in a burnup credit safety evaluation is the limited availability of relevant FP critical experiments for bias and bias uncertainty determination. This paper provides an evaluation of the available critical experiments that include FPs, along with bounding, burnup-dependent estimates of FP biases generated by combining energy dependent sensitivity data for a typical burnup credit application with the nuclear data uncertainty information distributed with SCALE 6. A method for determining separate bias and bias uncertainty values for individual FPs and illustrative results is presented. Finally, a FP bias calculation method based on data adjustment techniques and reactivity sensitivity coefficients calculated with the SCALE sensitivity/uncertainty tools and some typical results is presented. Using the methods described in this paper, the cross-section bias for a representative high-capacity spent fuel cask associated with the ENDF/B-VII nuclear data for 16 most important stable or near stable FPs is predicted to be no greater than 2% of the total worth of the 16 FPs, or less than 0.13 % k/k.

  14. Los Alamos National Laboratory strategic directions

    SciTech Connect

    Hecker, S.

    1995-10-01

    It is my pleasure to welcome you to Los Alamos. I like the idea of bringing together all aspects of the research community-defense, basic science, and industrial. It is particularly important in today`s times of constrained budgets and in fields such as neutron research because I am convinced that the best science and the best applications will come from their interplay. If we do the science well, then we will do good applications. Keeping our eye focused on interesting applications will spawn new areas of science. This interplay is especially critical, and it is good to have these communities represented here today.

  15. Graphite and Beryllium Reflector Critical Assemblies of UO2 (Benchmark Experiments 2 and 3)

    SciTech Connect

    Margaret A. Marshall; John D. Bess

    2012-11-01

    INTRODUCTION A series of experiments was carried out in 1962-65 at the Oak Ridge National Laboratory Critical Experiments Facility (ORCEF) for use in space reactor research programs. A core containing 93.2 wt% enriched UO2 fuel rods was used in these experiments. The first part of the experimental series consisted of 252 tightly-packed fuel rods (1.27-cm triangular pitch) with graphite reflectors [1], the second part used 252 graphite-reflected fuel rods organized in a 1.506-cm triangular-pitch array [2], and the final part of the experimental series consisted of 253 beryllium-reflected fuel rods in a 1.506-cm-triangular-pitch configuration and in a 7-tube-cluster configuration [3]. Fission rate distribution and cadmium ratio measurements were taken for all three parts of the experimental series. Reactivity coefficient measurements were taken for various materials placed in the beryllium reflected core. All three experiments in the series have been evaluated for inclusion in the International Reactor Physics Experiment Evaluation Project (IRPhEP) [4] and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) Handbooks, [5]. The evaluation of the first experiment in the series was discussed at the 2011 ANS Winter meeting [6]. The evaluations of the second and third experiments are discussed below. These experiments are of interest as benchmarks because they support the validation of compact reactor designs with similar characteristics to the design parameters for a space nuclear fission surface power systems [7].

  16. Determination of Critical Experiment Correlations Using the Sampler Sequence Within SCALE 6.2

    SciTech Connect

    Marshall, William BJ J; Rearden, Bradley T

    2015-01-01

    The validation of neutron transport methods used in nuclear criticality safety analyses is required by consensus American National Standards Institute/American Nuclear Society (ANSI/ANS) standards. In the last decade, there has been an increased interest in correlations among critical experiments used in validation that have shared physical attributes and which impact the independence of each measurement. The statistical methods included in many of the frequently cited guidance documents on performing validation calculations incorporate the assumption that all individual measurements are independent, so little guidance is available to practitioners on the topic. Typical guidance includes recommendations to select experiments from multiple facilities and experiment series in an attempt to minimize the impact of correlations or common-cause errors in experiments. Recent efforts have been made both to determine the magnitude of such correlations between experiments and to develop and apply methods for adjusting the bias and bias uncertainty to account for the correlations. This paper describes recent work performed at Oak Ridge National Laboratory using the Sampler sequence from the SCALE code system to develop experimental correlations using a Monte Carlo sampling technique. Sampler will be available for the first time with the release of SCALE 6.2, and a brief introduction to the methods used to calculate experiment correlations within this new sequence is presented in this paper. Techniques to utilize these correlations in the establishment of upper subcritical limits are the subject of a companion paper and will not be discussed here. Example experimental uncertainties and correlation coefficients are presented for a variety of low-enriched uranium water-moderated lattice experiments selected for use in a benchmark exercise by the Working Party on Nuclear Criticality Safety Subgroup on Uncertainty Analysis in Criticality Safety Analyses. The results include

  17. Consolidated fuel reprocessing program: Criticality experiments with fast test reactor fuel pins in an organic moderator

    SciTech Connect

    Bierman, S.R.

    1986-12-01

    The results obtained in a series of criticality experiments performed as part of a joint program on criticality data development between the United States Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan are presented in this report along with a complete description of the experiments. The experiments involved lattices of Fast Test Reactor (FTR) fuel pins in an organic moderator mixture similar to that used in the solvent extraction stage of fuel reprocessing. The experiments are designed to provide data for direct comparison with previously performed experimental measurements with water moderated lattices of FTR fuel pins. The same lattice arrangements and FTR fuel pin types are used in these organic moderated experimental assemblies as were used in the water moderated experiments. The organic moderator is a mixture of 38 wt % tributylphosphate in a normal paraffin hydrocarbon mixture of C{sub 11}H{sub 24} to C{sub 15}H{sub 32} molecules. Critical sizes of 1054.8, 599.2, 301.8, 199.5 and 165.3 fuel pins were obtained respectively for organic moderated lattices having 0.761 cm, 0.968 cm, 1.242 cm, 1.537 cm and 1.935 cm square lattice pitches as compared to 1046.9, 571.9, 293.9, 199.7 and 165.1 fuel pins for the same lattices water moderated.

  18. Criticality experiments with mixed oxide fuel pin arrays in plutonium-uranium nitrate solution

    SciTech Connect

    Lloyd, R.C. ); Smolen, G.R. )

    1988-08-01

    A series of critical experiments was completed with mixed plutonium-uranium solutions having a Pu/(Pu + U) ratio of approximately 0.22 in a boiler tube-type lattice assembly. These experiments were conducted as part of the Criticality Data Development Program between the United States Department of Energy (USDOE) and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. A complete description of the experiments and data are included in this report. The experiments were performed with an array of mixed oxide fuel pins in aqueous plutonium-uranium solutions. The fuel pins were contained in a boiler tube-type tank and arranged in a 1.4 cm square pitch array which resembled cylindrical geometry. One experiment was perfomed with the fuel pins removed from the vessel. The experiments were performed with a water reflector. The concentration of the solutions in the boiler tube-type tank was varied from 4 to 468 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was approximately 0.22 for all experiments.

  19. ASC platforms at Los Alamos.

    SciTech Connect

    Shaw, S. R.

    2004-01-01

    This talk describes the history, current state, and future plans for ASC computational and data storage service at Los Alamos. The of the systems and services described is limited to those installed in and managed by Group CCN-7.

  20. Los Alamos National Laboratory Overview

    SciTech Connect

    Neu, Mary

    2010-06-02

    Mary Neu, Associate Director for Chemistry, Life and Earth Sciences at Los Alamos National Laboratory, delivers opening remarks at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM

  1. Planning the Unplanned Experiment: Assessing the Efficacy of Standards for Safety Critical Software

    NASA Technical Reports Server (NTRS)

    Graydon, Patrick J.; Holloway, C. Michael

    2015-01-01

    We need well-founded means of determining whether software is t for use in safety-critical applications. While software in industries such as aviation has an excellent safety record, the fact that software aws have contributed to deaths illustrates the need for justi ably high con dence in software. It is often argued that software is t for safety-critical use because it conforms to a standard for software in safety-critical systems. But little is known about whether such standards `work.' Reliance upon a standard without knowing whether it works is an experiment; without collecting data to assess the standard, this experiment is unplanned. This paper reports on a workshop intended to explore how standards could practicably be assessed. Planning the Unplanned Experiment: Assessing the Ecacy of Standards for Safety Critical Software (AESSCS) was held on 13 May 2014 in conjunction with the European Dependable Computing Conference (EDCC). We summarize and elaborate on the workshop's discussion of the topic, including both the presented positions and the dialogue that ensued.

  2. Experience at the Los Alamos Meson Physics Facility with the use of alloy Inconel 718 as an enclosure for a beam degrader and as a proton beam entry window

    NASA Astrophysics Data System (ADS)

    Sommer, W. F.; Ferguson, P. D.; Brown, R. D.; Cedillo, C. M.; Zimmerman, E.

    Operation of the Los Alamos Meson Physics Facility (LAMPF) began in 1972 and continues at present. An injector delivers protons to a 0.8 km long line ar accelerator which produces a particle energy of 800 MeV; the protons are then transported to a variety of experimental areas. The proton beam is transported in a vacuum tube, controlled and bent by electromagnets. The highest intensity beam, at a maximum level of 1 mA, is delivered to the experimental area designated as Area A. At the end of the experimental area, the beam is transported through an interface between beamline vacuum and one atmosphere air pressure. This interface is made of metal and is generally referred to as a beam entry window. At LAMPF, after the beam has exited the vacuum tube, it becomes incident on a number of experiments or 'targets.' These include capsules for radiation damage studies, a beam 'degrader' for the long-term neutrino experiment, and as many nine targets in the Isotope Production (IP) stringer system used to produce medically significant isotopes. Following the IP system is a beam stop used for the purpose its name implies. The beam stop also contains a beam entry window, whose purpose is to separate the 250 psig water cooling environment from 1 atmosphere of air. The beam entry window, the beam degrader, and the beam stop window are made of alloy Inconel 718, have endured a lengthy irradiation service time at LAMPF, and are the subject of this report.

  3. Evaluation of the French Haut Taux de Combustion (HTC) Critical Experiment Data

    SciTech Connect

    Mueller, Don; Elam, Karla Riggle; Fox, Patricia B

    2008-09-01

    In the 1980s, a series of critical experiments referred to as the Haut Taux de Combustion (HTC) experiments was conducted by the Institut de Radioprotection et de Surete Nucleaire (IRSN) at the experimental criticality facility in Valduc, France. The plutonium-to- uranium ratio and the isotopic compositions of both the uranium and plutonium used in the simulated fuel rods were designed to be similar to what would be found in a typical pressurized-water reactor fuel assembly that initially had an enrichment of 4.5 wt% {sup 235}U and was burned to 37,500 MWd/MTU. The fuel material also includes {sup 241}Am, which is present due to the decay of {sup 241}Pu. The HTC experiments include configurations designed to simulate fuel handling activities, pool storage, and transport in casks constructed of thick lead or steel. Rights of use for the HTC experiment data were purchased under an agreement that limits release of the information. Consequently, a detailed and complete description of the experiments is not presented in this report. This report discusses evaluation of the four HTC data reports, modeling of the experiments, sensitivity and uncertainty analysis, and upper subcritical limit (USL) calculation. The report also presents some conclusions and recommendations concerning use of the HTC experiment data for burnup credit applications. The similarity of the HTC experiments with PWR spent nuclear fuel has been quantified using sensitivity/uncertainty analysis, confirming that the HTC experiments are significantly more applicable to the validation of burnup credit calculations than other available mixed-oxide (MOX) experiments. The HTC experiments were designed and executed with a high level of rigor, resulting in experimental uncertainties that are lower than many of the earlier MOX experiments. The HTC data reports, together with information provided in this report, provide sufficient data to allow for either detailed or simplified computational models to be

  4. Critical experiments on an enriched uranium solution system containing periodically distributed strong thermal neutron absorbers

    SciTech Connect

    Rothe, R.E.

    1996-09-30

    A series of 62 critical and critical approach experiments were performed to evaluate a possible novel means of storing large volumes of fissile solution in a critically safe configuration. This study is intended to increase safety and economy through use of such a system in commercial plants which handle fissionable materials in liquid form. The fissile solution`s concentration may equal or slightly exceed the minimum-critical-volume concentration; and experiments were performed for high-enriched uranium solution. Results should be generally applicable in a wide variety of plant situations. The method is called the `Poisoned Tube Tank` because strong neutron absorbers (neutron poisons) are placed inside periodically spaced stainless steel tubes which separate absorber material from solution, keeping the former free of contamination. Eight absorbers are investigated. Both square and triangular pitched lattice patterns are studied. Ancillary topics which closely model typical plant situations are also reported. They include the effect of removing small bundles of absorbers as might occur during inspections in a production plant. Not taking the tank out of service for these inspections would be an economic advantage. Another ancillary topic studies the effect of the presence of a significant volume of unpoisoned solution close to the Poisoned Tube Tank on the critical height. A summary of the experimental findings is that boron compounds were excellent absorbers, as expected. This was true for granular materials such as Gerstley Borate and Borax; but it was also true for the flexible solid composed of boron carbide and rubber, even though only thin sheets were used. Experiments with small bundles of absorbers intentionally removed reveal that quite reasonable tanks could be constructed that would allow a few tubes at a time to be removed from the tank for inspection without removing the tank from production service.

  5. Criticality experiments with low enriched UO/sub 2/ fuel rods in water containing dissolved gadolinium

    SciTech Connect

    Bierman, S.R.; Murphy, E.S.; Clayton, E.D.; Keay, R.T.

    1984-02-01

    The results obtained in a criticality experiments program performed for British Nuclear Fuels, Ltd. (BNFL) under contract with the United States Department of Energy (USDOE) are presented in this report along with a complete description of the experiments. The experiments involved low enriched UO/sub 2/ and PuO/sub 2/-UO/sub 2/ fuel rods in water containing dissolved gadolinium, and are in direct support of BNFL plans to use soluble compounds of the neutron poison gadolinium as a primary criticality safeguard in the reprocessing of low enriched nuclear fuels. The experiments were designed primarily to provide data for validating a calculation method being developed for BNFL design and safety assessments, and to obtain data for the use of gadolinium as a neutron poison in nuclear chemical plant operations - particularly fuel dissolution. The experiments program covers a wide range of neutron moderation (near optimum to very under-moderated) and a wide range of gadolinium concentration (zero to about 2.5 g Gd/l). The measurements provide critical and subcritical k/sub eff/ data (1 greater than or equal to k/sub eff/ greater than or equal to 0.87) on fuel-water assemblies of UO/sub 2/ rods at two enrichments (2.35 wt % and 4.31 wt % /sup 235/U) and on mixed fuel-water assemblies of UO/sub 2/ and PuO/sub 2/-UO/sub 2/ rods containing 4.31 wt % /sup 235/U and 2 wt % PuO/sub 2/ in natural UO/sub 2/ respectively. Critical size of the lattices was determined with water containing no gadolinium and with water containing dissolved gadolinium nitrate. Pulsed neutron source measurements were performed to determine subcritical k/sub eff/ values as additional amounts of gadolinium were successively dissolved in the water of each critical assembly. Fission rate measurements in /sup 235/U using solid state track recorders were made in each of the three unpoisoned critical assemblies, and in the near-optimum moderated and the close-packed poisoned assemblies of this fuel.

  6. SCALE TSUNAMI Analysis of Critical Experiments for Validation of 233U Systems

    SciTech Connect

    Mueller, Don; Rearden, Bradley T

    2009-01-01

    Oak Ridge National Laboratory (ORNL) staff used the SCALE TSUNAMI tools to provide a demonstration evaluation of critical experiments considered for use in validation of current and anticipated operations involving {sup 233}U at the Radiochemical Development Facility (RDF). This work was reported in ORNL/TM-2008/196 issued in January 2009. This paper presents the analysis of two representative safety analysis models provided by RDF staff.

  7. [Phenomenologic study about experiences when living the death in the neonatal critical care unit].

    PubMed

    Silva, Laureana Cartaxo Salgado Pereira; Valença, Cecília Nogueira; Germano, Raimunda Medeiros

    2010-01-01

    This research aimed at describing the care experiences of neonatal critical care nurses when facing the death and to understand their feelings before the death of the newborn. Qualitative research with a phenomenological approach, with the guiding question: How do you feel about the death of the newborn ICU where you work? Attended the interview 12 nurses and ICU nursing. Emerging feelings such as guilt, failure and denial. Understanding the phenomenon being studied, we affirm that the death of the newborn within the ICU is an experience of conflicting feelings, sometimes painful for the nurses.

  8. Nuclear criticality research at the University of New Mexico

    SciTech Connect

    Busch, R.D.

    1997-06-01

    Two projects at the University of New Mexico are briefly described. The university`s Chemical and Nuclear Engineering Department has completed the final draft of a primer for MCNP4A, which it plans to publish soon. The primer was written to help an analyst who has little experience with the MCNP code to perform criticality safety analyses. In addition, the department has carried out a series of approach-to-critical experiments on the SHEBA-II, a UO{sub 2}F{sub 2} solution critical assembly at Los Alamos National Laboratory. The results obtained differed slightly from what was predicted by the TWODANT code.

  9. MCNP analysis of PNL split-table critical experiments containing mixed-oxide fuels

    SciTech Connect

    Abdurrahman, N.M.; Yavuz, M.; Radulescu, G.

    1997-12-01

    Pacific Northwest Laboratory (PNL) Split-Table Critical experiments containing mixed-oxide (MOX) fuels for various core configurations are studied using MCNP4A with the ENDF/B-VI continuous-energy library. These experiments were performed to provide necessary technical information and experimental criticality data that would serve as benchmark data in support of the liquid-metal fast breeder reactor program. Because of the current interest in the utilization of weapons-grade plutonium in the form of MOX fuel in light water reactors, such experimental data are extremely important for checking the performance of the modem computational tools. The {sup 239}Pu content in plutonium of the PNL MOX fuels is {approximately}91 wt%, which is very close to that of the weapons-grade {sup 239}Pu. The MOX fuels used in these critical experiments consist of 30.0, 14.62, and 7.89 wt% Pu and N{sub H}/(N{sub Pu} + Nu) moderation ratios (MRs) of 47.4, 30.6, and 51.8, respectively.

  10. Planning the Unplanned Experiment: Towards Assessing the Efficacy of Standards for Safety-Critical Software

    NASA Technical Reports Server (NTRS)

    Graydon, Patrick J.; Holloway, C. M.

    2015-01-01

    Safe use of software in safety-critical applications requires well-founded means of determining whether software is fit for such use. While software in industries such as aviation has a good safety record, little is known about whether standards for software in safety-critical applications 'work' (or even what that means). It is often (implicitly) argued that software is fit for safety-critical use because it conforms to an appropriate standard. Without knowing whether a standard works, such reliance is an experiment; without carefully collecting assessment data, that experiment is unplanned. To help plan the experiment, we organized a workshop to develop practical ideas for assessing software safety standards. In this paper, we relate and elaborate on the workshop discussion, which revealed subtle but important study design considerations and practical barriers to collecting appropriate historical data and recruiting appropriate experimental subjects. We discuss assessing standards as written and as applied, several candidate definitions for what it means for a standard to 'work,' and key assessment strategies and study techniques and the pros and cons of each. Finally, we conclude with thoughts about the kinds of research that will be required and how academia, industry, and regulators might collaborate to overcome the noted barriers.

  11. Analysis of Godiva-IV delayed-critical and static super-prompt-critical conditions

    SciTech Connect

    Mosteller, Russell D; Goda, Joetta M

    2009-01-01

    Super-prompt-critical burst experiments were conducted on the Godiva-IV assembly at Los Alamos National Laboratory from the 1960s through 2005. Detailed and simplified benchmark models have been constructed for four delayed-critical experiments and for the static phase of a super-prompt-critical burst experiment. In addition, a two-dimensional cylindrical model has been developed for the super-prompt-critical condition. Criticality calculations have been performed for all of those models with four modern nuclear data libraries: ENDFIB-VI, ENDF/8-VII.0, JEFF-3.1 , and JENDL-3.3. Overall, JENDL-3.3 produces the best agreement with the reference values for k{sub eff}.

  12. Recollections of a very junior physicist at Los Alamos, 1944-1946

    NASA Astrophysics Data System (ADS)

    French, Anthony P.

    2008-04-01

    The author came to Los Alamos as a member of the British Mission after two years of making fission cross section measurements at the Cavendish Laboratory. He worked in a group headed by Egon Bretscher in Enrico Fermi's F Division. The talk presents his personal memories and experiences at Los Alamos as compared to his life and work in wartime Britain.

  13. Critical Experiments With Aqueous Solutions of {sup 233}UO{sub 2}(NO{sub 3}){sub 2}

    SciTech Connect

    Thomas, J.T.

    2001-05-17

    This report provides the critical experimenter's interpretations and descriptions of informal critical experiment logbook notes and associated information (e.g., experimental equipment designs/sketches, chemical and isotopic analyses, etc.) for the purpose of formally documenting the results of critical experiments performed in the late 1960s at the Oak Ridge Critical Experiments Facility. The experiments were conducted with aqueous solutions of 97.6 wt % {sup 233}U uranyl nitrate having uranium densities varying between about 346 g U/l and 45 g U/l. Criticality was achieved with single simple units (e.g., cylinders and spheres) and with spaced subcritical simple cylindrical units arranged in unreflected, water-reflected, and polyethylene reflected critical arrays.

  14. Critical Experiments With Aqueous Solutions of {sup 233}UO{sub 2}(NO{sub ;3}){sub 2}

    SciTech Connect

    Thomas, J T

    2001-05-17

    This report provides the critical experimenter's interpretations and descriptions of informal critical experiment logbook notes and associated information (e.g., experimental equipment designs/sketches, chemical and isotopic analyses, etc.) for the purpose of formally documenting the results of critical experiments performed in the late 1960s at the Oak Ridge Critical Experiments Facility. The experiments were conducted with aqueous solutions of 97.6 wt % {sup 233}U uranyl nitrate having uranium densities varying between about 346 g U/l and 45 g U/l. Criticality was achieved with single simple units (e.g., cylinders and spheres) and with spaced subcritical simple cylindrical units arranged in unreflected, water-reflected, and polyethylene reflected critical arrays.

  15. Correlation between Knowledge, Experience and Common Sense, with Critical Thinking Capability of Medical Faculty's Students at Indonesia Christian University

    ERIC Educational Resources Information Center

    Nadeak, Bernadetha

    2015-01-01

    This research discusses correlation between knowledge, experience and common sense with critical thinking of Medical Faculty's Student. As to the objective of this research is to find the correlation between knowledge, experience and common sense with critical thinking of Medical Faculty's Students at Christian University of Indonesia. It is…

  16. Women, Poverty, and Educational Success: A Critical Exploration of Low-Income Women's Experience in Community Colleges

    ERIC Educational Resources Information Center

    Barry, Kate R.

    2012-01-01

    The purpose of this study is to critically explore low-income women's experience as they negotiate post secondary education in community colleges. Three research questions explore the context through which low-income women have entered the college experience, what that experience is like for them, and how the community college experience has…

  17. Integrated Verification Experiment data collected as part of the Los Alamos National Laboratory`s Source Region Program. Appendix D: Ionospheric measurements for IVEs

    SciTech Connect

    Fitzgerald, T.J.; Carlos, R.C.; Argo, P.E.

    1993-01-21

    As part of the integrated verification experiment (IVE), we deployed a network of hf ionospheric sounders to detect the effects of acoustic waves generated by surface ground motion following underground nuclear tests at the Nevada Test Site. The network sampled up to four geographic locations in the ionosphere from almost directly overhead of the surface ground zero out to a horizontal range of 60 km. We present sample results for four of the IVEs: Misty Echo, Texarkana, Mineral Quarry, and Bexar.

  18. Charge exchange contamination of CRIT-II barium CIV experiment. [critical ionization velocity in ionosphere

    NASA Technical Reports Server (NTRS)

    Swenson, G. R.; Mende, S. B.; Meyerott, R. E.; Rairden, R. L.

    1991-01-01

    Experiments have been recently performed which attempted to confirm critical ionization velocity (CIV) ionization by deploying chemicals at high velocity in the ionosphere. Specifically, the CRIT-II rocket performed a barium release in the ionosphere, where observations of Ba(+) resonant emissions following the release are believed to have resulted from the CIV process. Calculations are presented which suggest a significant fraction (if not all) of the Ba(+) observed likely resulted from charge exchange with the thermosphere ions and not through CIV processes. The results presented here are pertinent to other CIV experiments performed in the ionosphere. It is recommended that laboratory measurements should be made of the charge exchange cross section between O(+) and Ba as well as other metal vapors used in CIV experiments.

  19. 'Visual’ parsing can be taught quickly without visual experience during critical periods

    PubMed Central

    Reich, Lior; Amedi, Amir

    2015-01-01

    Cases of invasive sight-restoration in congenital blind adults demonstrated that acquiring visual abilities is extremely challenging, presumably because visual-experience during critical-periods is crucial for learning visual-unique concepts (e.g. size constancy). Visual rehabilitation can also be achieved using sensory-substitution-devices (SSDs) which convey visual information non-invasively through sounds. We tested whether one critical concept – visual parsing, which is highly-impaired in sight-restored patients – can be learned using SSD. To this end, congenitally blind adults participated in a unique, relatively short (~70 hours), SSD-‘vision’ training. Following this, participants successfully parsed 2D and 3D visual objects. Control individuals naïve to SSDs demonstrated that while some aspects of parsing with SSD are intuitive, the blind’s success could not be attributed to auditory processing alone. Furthermore, we had a unique opportunity to compare the SSD-users’ abilities to those reported for sight-restored patients who performed similar tasks visually, and who had months of eyesight. Intriguingly, the SSD-users outperformed the patients on most criteria tested. These suggest that with adequate training and technologies, key high-order visual features can be quickly acquired in adulthood, and lack of visual-experience during critical-periods can be somewhat compensated for. Practically, these highlight the potential of SSDs as standalone-aids or combined with invasive restoration approaches. PMID:26482105

  20. Survey of Canadian critical care nurses' experiences of conflict in intensive care units.

    PubMed

    Edwards, Marie; Throndson, Karen; Girardin, Julie

    2012-01-01

    The purpose of this study was to enhance our understanding of Canadian critical care nurses' experiences of and responses to situations of conflict in the ICU. Through a 35-item web-based survey, members of the Canadian Association of Critical Care Nurses were asked questions regarding the types, causes and frequency of conflict experienced, the nursing interventions found most helpful in situations of conflict, and the resources found most helpful in responding to situations of conflict. A total of 241 nurses responded to the survey. The mean age of the nurses was 43 years, and the majority were female (89.2%), direct care providers (66.4%), with greater than 11 years of experience in critical care (58.3%), and working in medical/surgical ICUs (66.4%) in tertiary care hospitals (67.2%). Approximately 51% of the nurses reported being involved in at least one situation of conflict related to the management of a patient in the last week worked. The most common types of conflict encountered were disagreements between the team and family (46.5%) or within the team (35.3%). The nurses acknowledged the importance of clear, consistent and honest communication with patients and families when conflict arises and rank-ordered the resources found most helpful to patients, families, and nurses in conflict situations. Implications for practice and education are discussed and recommendations for future research are outlined.

  1. From idealistic helper to enterprising learner: critical reflections on personal development through experiences from Afghanistan.

    PubMed

    Wickford, Jenny; Rosberg, Susanne

    2012-05-01

    There is little written about the cultural, social, and ethical challenges encountered by physiotherapists engaging in development work. This article takes a critical perspective on what it means to engage in development work as an expatriate physiotherapist, through a self-critical reflection on experiences from Afghanistan. The field notes from an ethnographic study of a development project conducted in Afghanistan were analysed to explore the transformative process of personal and professional development of the development worker. The critical reflective process entailed a change in meaning perspective, described as a shift from the position of an Idealistic Helper to an Enterprising Learner. Of importance in this process were "disorienting dilemmas" that challenged personal perceptions. Critical reflection over such dilemmas led to deeper understanding facilitating the process of change. The essential lesson learned is that the baseline for understanding others is an understanding of one's own meaning perspectives and manner of participation in relation to others and their context. The insights gained have implications for physiotherapists working in development contexts, for other development workers, and for physiotherapists working with patients in clinical practice in a nondevelopment context. Exploring how to collaborate in development contexts could be done using reflective groups with expatriate and local physiotherapists and/or patients. This could lead to greater understanding of oneself, each other, and the local context.

  2. From idealistic helper to enterprising learner: critical reflections on personal development through experiences from Afghanistan.

    PubMed

    Wickford, Jenny; Rosberg, Susanne

    2012-05-01

    There is little written about the cultural, social, and ethical challenges encountered by physiotherapists engaging in development work. This article takes a critical perspective on what it means to engage in development work as an expatriate physiotherapist, through a self-critical reflection on experiences from Afghanistan. The field notes from an ethnographic study of a development project conducted in Afghanistan were analysed to explore the transformative process of personal and professional development of the development worker. The critical reflective process entailed a change in meaning perspective, described as a shift from the position of an Idealistic Helper to an Enterprising Learner. Of importance in this process were "disorienting dilemmas" that challenged personal perceptions. Critical reflection over such dilemmas led to deeper understanding facilitating the process of change. The essential lesson learned is that the baseline for understanding others is an understanding of one's own meaning perspectives and manner of participation in relation to others and their context. The insights gained have implications for physiotherapists working in development contexts, for other development workers, and for physiotherapists working with patients in clinical practice in a nondevelopment context. Exploring how to collaborate in development contexts could be done using reflective groups with expatriate and local physiotherapists and/or patients. This could lead to greater understanding of oneself, each other, and the local context. PMID:22047471

  3. Participation in ICZM initiatives: critical aspects and lessons learnt from the Mediterranean and Black Sea experiences.

    PubMed

    Soriani, Stefano; Buono, Fabrizia; Tonino, Marco; Camuffo, Monica

    2015-03-15

    Public participation is recognized as a necessary tool to ensure a successful implementation of Integrated Coastal Zone Management (ICZM) strategies and plans. This paper, based on the experiences carried out in the Mediterranean and in the Black Sea within the EU FP7 project PEGASO, presents some critical aspects and lessons learnt regarding participation in ICZM projects. The research shows that data availability, the complexity of data interpretation, an inadequate legal and cultural framework and the difficulties in promoting integration of all the components of coastal management within short term projects are all elements that if not properly considered since the beginning of the participatory process may hinder public participation effectiveness. Moreover the definition of the spatial scale of coastal phenomenon as well as the discrepancy between the local scale of coastal governance and the complex multi-scale nature of coastal systems remain highly critical aspects to be addressed. PMID:25659448

  4. A framework guiding critical thinking through reflective journal documentation: a Middle Eastern experience.

    PubMed

    Simpson, Elaine; Courtney, Mary

    2007-08-01

    The purpose of this paper is to present a framework to guide critical thinking through reflective journaling, and describe how a group of 20 Middle Eastern nurses used reflective journaling to enhance their practice. Journal documentation was used during clinical practicum to foster the development of critical thinking in order to assist nurses when analysing and evaluating their clinical experiences. The findings from this study demonstrated that nurses accepted the framework for journal documentation because it provided structure for reflection, speculation, synthesis and metacognition of events experienced during clinical practice. Journaling gave nurses the opportunity to transfer thoughts onto paper and write down subjective and objective data, and created dialogue between the nurse educators and nurses. They were engaged in productive and positive activity to enhance their nursing practice. Nurses also commented that writing helped to develop their confidence in writing English.

  5. Critical mass experiment using U-235 foils-SiO{sub 2}-polyethylene plates

    SciTech Connect

    Sanchez, R.; Kimpland, R.; Butterfield, K.; Jaegers, P.; Casson, W.

    1998-12-31

    Fissile material in waste is frequently encountered in decontamination and decommissioning activities. Thousands of drums containing radioactive waste are stored in storage facilities throughout the DOE complex. The amount of fissile material in each drum is generally small because of the criticality safety limits that have been calculated using neutron transport computer codes such as MCNP, KENO, or ONEDANT. No experimental critical data are available to assure the correctiveness of the calculations for those systems containing fissile material (U-235, U-233, and Pu-239) in contact with matrix material (Al{sub 2}O{sub 3}, CaO, MgO, and SiO{sub 2}) in the drums. The purpose of the U-235 foil-SiO{sub 2}-polyethylene experiment is to provide experimental data to validate the computer transport codes and the cross section data.

  6. Critical mass experiment using {sup 235}U foil-SiO{sub 2}-polyethylene plates

    SciTech Connect

    Sanchez, R.; Kimpland, R.; Butterfield, K.; Jaegers, P.; Casson, W.

    1998-12-31

    Fissile material in waste is frequently encountered in decontamination and decommissioning activities. Thousands of drums containing radioactive waste are stored in storage facilities throughout the US Department of Energy (DOE) complex. The amount of fissile material in each drum is generally small because of the criticality safety limits that have been calculated using neutron transport computer codes such as MCNP, KENO, or ONEDANT. No experimental critical data are available to ensure the correctness of the calculations for those systems containing fissile material ({sup 235}U, {sup 233}U, and {sup 239}Pu) in contact with matrix material (Al{sub 2}O{sub 3}, CaO, MgO, and SiO{sub 2}) in the drums. The purpose of the {sup 235}U foil-SiO{sub 2}-polyethylene experiment is to provide experimental data to validate the computer transport codes and the cross-section data.

  7. Participation in ICZM initiatives: critical aspects and lessons learnt from the Mediterranean and Black Sea experiences.

    PubMed

    Soriani, Stefano; Buono, Fabrizia; Tonino, Marco; Camuffo, Monica

    2015-03-15

    Public participation is recognized as a necessary tool to ensure a successful implementation of Integrated Coastal Zone Management (ICZM) strategies and plans. This paper, based on the experiences carried out in the Mediterranean and in the Black Sea within the EU FP7 project PEGASO, presents some critical aspects and lessons learnt regarding participation in ICZM projects. The research shows that data availability, the complexity of data interpretation, an inadequate legal and cultural framework and the difficulties in promoting integration of all the components of coastal management within short term projects are all elements that if not properly considered since the beginning of the participatory process may hinder public participation effectiveness. Moreover the definition of the spatial scale of coastal phenomenon as well as the discrepancy between the local scale of coastal governance and the complex multi-scale nature of coastal systems remain highly critical aspects to be addressed.

  8. The critical warzone experiences (CWE) scale: initial psychometric properties and association with PTSD, anxiety, and depression.

    PubMed

    Kimbrel, Nathan A; Evans, Lianna D; Patel, Amee B; Wilson, Laura C; Meyer, Eric C; Gulliver, Suzy B; Morissette, Sandra B

    2014-12-30

    The objective of the present research was to develop and evaluate a critical warzone experiences (CWE) scale for use with Iraq/Afghanistan veterans. The psychometric properties of the CWE were evaluated across three independent samples of Iraq/Afghanistan veterans. Despite its brevity (7 items), the CWE exhibited good internal consistency (average α =0.83), good temporal stability (1-year test-retest reliability=0.73), good concurrent validity with lengthier measures of warzone experiences (average r=0.74), and a clear unidimensional factor structure (average factor loading=0.69). Study 2 confirmed the CWE׳s factor structure through confirmatory factor analysis, and structural equation modeling demonstrated a strong association between CWE and post-deployment mental health, β =0.49, p<0.001. Study 3 provided further support for the predictive validity of the CWE by demonstrating that it was associated with PTSD diagnosis, clinician-rated PTSD symptom severity, and global functional impairment in an independent sample of Iraq/Afghanistan veterans (average r=0.59). While replication of these findings in more diverse samples is needed, the preliminary evidence from these studies indicates that the CWE is a brief, reliable, and valid measure of critical warzone experiences among Iraq/Afghanistan war veterans.

  9. Critical experiments on single-unit spherical plutonium geometries reflected and moderated by oil

    SciTech Connect

    Rothe, R.E.

    1997-05-01

    Experimental critical configurations are reported for several dozen spherical and hemispherical single-unit assemblies of plutonium metal. Most were solid but many were hollow-centered, thick, shell-like geometries. All were constructed of nested plutonium (mostly {sup 2139}Pu) metal hemispherical shells. Three kinds of critical configurations are reported. Two required interpolation and/or extrapolation of data to obtain the critical mass because reflector conditions were essentially infinite. The first finds the plutonium essentially fully reflected by a hydrogen-rich oil; the second is essentially unreflected. The third kind reports the critical oil reflector height above a large plutonium metal assembly of accurately known mass (no interpolation required) when that mass was too great to permit full oil reflection. Some configurations had thicknesses of mild steel just outside the plutonium metal, separating it from the oil. These experiments were performed at the Rocky Flats Critical Mass Laboratory in the late 1960s. They have not been published in a form suitable for benchmark-quality comparisons against state-of-the-art computational techniques until this paper. The age of the data and other factors lead to some difficulty in reconstructing aspects of the program and may, in turn, decrease confidence in certain details. Whenever this is true, the point is acknowledged. The plutonium metal was alpha-phase {sup 239}Pu containing 5.9 wt-% {sup 240}Pu. All assemblies were formed by nesting 1.667-mm-thick (nominal) bare plutonium metal hemispherical shells, also called hemishells, until the desired configuration was achieved. Very small tolerance gaps machined into radial dimensions reduced the effective density a small amount in all cases. Steel components were also nested hemispherical shells; but these were nominally 3.333-mm thick. Oil was used as the reflector because of its chemical compatibility with plutonium metal.

  10. Long-Term Soil Experiments: A Key to Managing Earth's Rapidly Changing Critical Zones

    NASA Astrophysics Data System (ADS)

    Richter, D., Jr.

    2014-12-01

    In a few decades, managers of Earth's Critical Zones (biota, humans, land, and water) will be challenged to double food and fiber production and diminish adverse effects of management on the wider environment. To meet these challenges, an array of scientific approaches is being used to increase understanding of Critical Zone functioning and evolution, and one amongst these approaches needs to be long-term soil field studies to move us beyond black boxing the belowground Critical Zone, i.e., to further understanding of processes driving changes in the soil environment. Long-term soil experiments (LTSEs) provide direct observations of soil change and functioning across time scales of decades, data critical for biological, biogeochemical, and environmental assessments of sustainability; for predictions of soil fertility, productivity, and soil-environment interactions; and for developing models at a wide range of temporal and spatial scales. Unfortunately, LTSEs globally are not in a good state, and they take years to mature, are vulnerable to loss, and even today remain to be fully inventoried. Of the 250 LTSEs in a web-based network, results demonstrate that soils and belowground Critical Zones are highly dynamic and responsive to human management. The objective of this study is to review the contemporary state of LTSEs and consider how they contribute to three open questions: (1) can soils sustain a doubling of food production in the coming decades without further impinging on the wider environment, (2) how do soils interact with the global C cycle, and (3) how can soil management establish greater control over nutrient cycling. While LTSEs produce significant data and perspectives for all three questions, there is on-going need and opportunity for reviews of the long-term soil-research base, for establishment of an efficiently run network of LTSEs aimed at sustainability and improving management control over C and nutrient cycling, and for research teams that

  11. Acoustic Experiment to Measure the Bulk Viscosity of Near-Critical Xenon in Microgravity

    NASA Technical Reports Server (NTRS)

    Gillis, K. A.; Shinder, I.; Moldover, M. R.; Zimmerli, G. A.

    2002-01-01

    We plan a rigorous test of the theory of dynamic scaling by accurately measuring the bulk viscosity of xenon in microgravity 50 times closer to the critical temperature T(sub c) than previous experiments. The bulk viscosity zeta (or "second viscosity" or "dilational viscosity") will be determined by measuring the attenuation length of sound alpha lambda and also measuring the frequency-dependence of the speed of sound. For these measurements, we developed a unique Helmholtz resonator and specialized electro-acoustic transducers. We describe the resonator, the transducers, their performance on Earth, and their expected performance in microgravity.

  12. Analysis of a boron-carbide-drum-controlled critical reactor experiment

    NASA Technical Reports Server (NTRS)

    Mayo, W. T.

    1972-01-01

    In order to validate methods and cross sections used in the neutronic design of compact fast-spectrum reactors for generating electric power in space, an analysis of a boron-carbide-drum-controlled critical reactor was made. For this reactor the transport analysis gave generally satisfactory results. The calculated multiplication factor for the most detailed calculation was only 0.7-percent Delta k too high. Calculated reactivity worth of the control drums was $11.61 compared to measurements of $11.58 by the inverse kinetics methods and $11.98 by the inverse counting method. Calculated radial and axial power distributions were in good agreement with experiment.

  13. Undergraduate experiment in critical phenomena. II. The coexistence curve of a binary fluid mixture

    NASA Astrophysics Data System (ADS)

    Ngubane, S. B.; Jacobs, D. T.

    1986-06-01

    An undergraduate experiment is described that uses meniscus heights to determine the coexistence curve of a binary fluid mixture. The data can be obtained with a minimum of equipment and yield results that are easily interpreted by the theory also presented. Data taken on the binary liquid mixture methanol-isooctane are presented and analyzed. The critical temperature and composition were found to be (42.5±0.5) °C and (67.3±0.2)% by volume isooctane, respectively.

  14. Los Alamos Using Neutrons to Stop Nuclear Smugglers

    ScienceCinema

    Favalli, Andrea; Swinhoe, Martyn

    2016-07-12

    Los Alamos National Laboratory researchers have successfully demonstrated for the first time that laser-generated neutrons can be enlisted as a useful tool in the War on Terror. The international research team used the short-pulse laser at Los Alamos's TRIDENT facility to generate a neutron beam with novel characteristics that interrogated a closed container to confirm the presence and quantity of nuclear material inside. The successful experiment paves the way for creation of a table-top-sized or truck-mounted neutron generator that could be installed at strategic locations worldwide to thwart smugglers trafficking in nuclear materials.

  15. Los Alamos Using Neutrons to Stop Nuclear Smugglers

    SciTech Connect

    Favalli, Andrea; Swinhoe, Martyn

    2013-06-03

    Los Alamos National Laboratory researchers have successfully demonstrated for the first time that laser-generated neutrons can be enlisted as a useful tool in the War on Terror. The international research team used the short-pulse laser at Los Alamos's TRIDENT facility to generate a neutron beam with novel characteristics that interrogated a closed container to confirm the presence and quantity of nuclear material inside. The successful experiment paves the way for creation of a table-top-sized or truck-mounted neutron generator that could be installed at strategic locations worldwide to thwart smugglers trafficking in nuclear materials.

  16. Space, the final frontier: A critical review of recent experiments performed in microgravity.

    PubMed

    Vandenbrink, Joshua P; Kiss, John Z

    2016-02-01

    Space biology provides an opportunity to study plant physiology and development in a unique microgravity environment. Recent space studies with plants have provided interesting insights into plant biology, including discovering that plants can grow seed-to-seed in microgravity, as well as identifying novel responses to light. However, spaceflight experiments are not without their challenges, including limited space, limited access, and stressors such as lack of convection and cosmic radiation. Therefore, it is important to design experiments in a way to maximize the scientific return from research conducted on orbiting platforms such as the International Space Station. Here, we provide a critical review of recent spaceflight experiments and suggest ways in which future experiments can be designed to improve the value and applicability of the results generated. These potential improvements include: utilizing in-flight controls to delineate microgravity versus other spaceflight effects, increasing scientific return via next-generation sequencing technologies, and utilizing multiple genotypes to ensure results are not unique to one genetic background. Space experiments have given us new insights into plant biology. However, to move forward, special care should be given to maximize science return in understanding both microgravity itself as well as the combinatorial effects of living in space. PMID:26795156

  17. Space, the final frontier: A critical review of recent experiments performed in microgravity.

    PubMed

    Vandenbrink, Joshua P; Kiss, John Z

    2016-02-01

    Space biology provides an opportunity to study plant physiology and development in a unique microgravity environment. Recent space studies with plants have provided interesting insights into plant biology, including discovering that plants can grow seed-to-seed in microgravity, as well as identifying novel responses to light. However, spaceflight experiments are not without their challenges, including limited space, limited access, and stressors such as lack of convection and cosmic radiation. Therefore, it is important to design experiments in a way to maximize the scientific return from research conducted on orbiting platforms such as the International Space Station. Here, we provide a critical review of recent spaceflight experiments and suggest ways in which future experiments can be designed to improve the value and applicability of the results generated. These potential improvements include: utilizing in-flight controls to delineate microgravity versus other spaceflight effects, increasing scientific return via next-generation sequencing technologies, and utilizing multiple genotypes to ensure results are not unique to one genetic background. Space experiments have given us new insights into plant biology. However, to move forward, special care should be given to maximize science return in understanding both microgravity itself as well as the combinatorial effects of living in space.

  18. A progress report on UNICOS misuse detection at Los Alamos

    SciTech Connect

    Thompson, J.L.; Jackson, K.A.; Stallings, C.A.; Simmonds, D.D.; Siciliano, C.L.B.; Pedicini, G.A.

    1995-10-01

    An effective method for detecting computer misuse is the automatic monitoring and analysis of on-line user activity. During the past year, Los Alamos enhanced its Network Anomaly Detection and Intrusion Reporter (NADIR) to include analysis of user activity on Los Alamos` UNICOS Crays. In near real-time, NADIR compares user activity to historical profiles and tests activity against expert rules. The expert rules express Los Alamos` security policy and define improper or suspicious behavior. NADIR reports suspicious behavior to security auditors and provides tools to aid in follow-up investigations. This paper describes the implementation to date of the UNICOS component of NADIR, along with the operational experiences and future plans for the system.

  19. Optical velocimetry at the Los Alamos Proton Radiography Facility

    NASA Astrophysics Data System (ADS)

    Tupa, Dale; Tainter, Amy; Neukirch, Levi; Hollander, Brian; Buttler, William; Holtkamp, David; The Los Alamos Proton Radiography Team Team

    2016-05-01

    The Los Alamos Proton Radiography Facility (pRad) employs a high-energy proton beam to image the properties and behavior of materials driven by high explosives. We will discuss features of pRad and describe some recent experiments, highlighting optical diagnostics for surface velocity measurements.

  20. Working with Fermi at Chicago and Los Alamos

    NASA Astrophysics Data System (ADS)

    Garwin, Richard L.

    2010-02-01

    I discuss my experience with Enrico Fermi as student and fellow faculty member at Chicago and with him as consultants to the Los Alamos Scientific Laboratory in 1950-1952. The talk shares observations about this great physicist and exemplary human being. )

  1. Information about Practicums at Los Alamos

    SciTech Connect

    Bradley, Paul A.

    2012-07-24

    The Los Alamos Neutron Science Center is the premier facility for neutron science experiments ranging from cross section measurements, neutron scattering experiments, proton radiography, cold neutrons, actinide neutronic properties, and many other exciting topics. The National High Magnetic Field Laboratory is home to several powerful magnets, including the one that created the first non-destructive 100 Tesla field in March 2012. They probe the electronic structure of superconductors, magnetic properties of materials (including magneto-quantum effects). Research is also conducted in correlated materials, thermoacoustics, and magnetic properties of actinides. The Trident Laser has a unique niche with very high power, short pulse experiments, with a peak power of 10{sup 20} W in short pulse mode. Discoveries range from production of monoenergetic MeV ion beam, nonlinear kinetic plasma waves, the transition between kinetic and fluid nonlinear behavior and other laser-plasma interaction processes.

  2. Plasma-wall interaction data needs critical to a Burning Core Experiment (BCX)

    SciTech Connect

    Not Available

    1985-11-01

    The Division of Development and Technology has sponsored a four day US-Japan workshop ''Plasma-Wall Interaction Data Needs Critical to a Burning Core Experiment (BCX)'', held at Sandia National Laboratories, Livermore, California on June 24 to 27, 1985. The workshop, which brought together fifty scientists and engineers from the United States, Japan, Germany, and Canada, considered the plasma-material interaction and high heat flux (PMI/HHF) issues for the next generation of magnetic fusion energy devices, the Burning Core Experiment (BCX). Materials options were ranked, and a strategy for future PMI/HHF research was formulated. The foundation for international collaboration and coordination of this research was also established. This volume contains the last three of the five technical sessions. The first of the three is on plasma materials interaction issues, the second is on research facilities and the third is from smaller working group meetings on graphite, beryllium, advanced materials and future collaborations.

  3. Defect printability of alternating phase-shift mask: a critical comparison of simulation and experiment

    NASA Astrophysics Data System (ADS)

    Ozawa, Ken; Komizo, Tooru; Kikuchi, Koji; Ohnuma, Hidetoshi; Kawahira, Hiroichi

    2002-07-01

    An alternative phase shift mask (alt-PSM) is a promising device for extending optical lithography to finer design rules. There have been few reports, however, on the mask's ability to identify phase defects. We report here an alt-PSM of a dual-trench type for KrF exposure, with programmed quartz defects used to evaluate defect printability by measuring aerial images with a Zeiss MSM100 measuring system. The experimental results are simulated using the TEMPEST program. First, a critical comparison of the simulation and the experiment is conducted. The actual measured topography of quartz defects are used in the simulation. Moreover, a general simulation study on defect printability using an alt-PSM for ArF exposure is conducted. The defect dimensions, which produce critical CD errors are determined by simulation that takes into account the full 3-dimensional structure of phase defects as well as a simplified structure. The critical dimensions of an isolated defect identified by the alt-PSM of a single-trench type for ArF exposure are 240 nm in bottom diameter and 50 degrees in height (phase) for the cylindrical shape and 240 nm in bottom diameter and 90 degrees in height (phase) for the rotating trapezoidal shape, where the CD error limit is +/- 5%.

  4. Pathways and pipelines: Self-reported critical experiences for expert and novice geologists

    NASA Astrophysics Data System (ADS)

    LaDue, N.; Pacheco, H. A.

    2011-12-01

    The recruitment and retention of geology students has received attention due to pressure from industry to replenish an aging workforce nearing retirement (Gonzales and Keane, 2010). Thorough, qualitative studies have been conducted using critical incident methodology to understand what experiences cause various groups of people to choose careers in the geosciences or geoscience degree programs (Levine et al., 2007; Houlton, 2010). This study both builds upon earlier studies and provides new insights about capacity building in the geosciences. Individuals who have been successfully pipelined into the geosciences ranging from upper-level undergraduates to decades-long professionals, were selected for an expert-novice study about field mapping. All of the 38 participants have field-mapping experience and were selected to achieve a balance of age, gender and experience in the sample and secondarily based on geographic diversity. Participants were asked how they became interested in geology as the last question of an interview about the other tasks during the study. Participants were surficially probed, in contrast to in-depth interviews conducted using critical incident methods. Remarkably, though the interview question was unstructured and open ended, the three persistent themes that emerged are consistent with previous studies of women geologists (Holmes and O'Connell, 2003), under-represented minorities (Levine et al., 2007), and undergraduate geoscience majors (Houlton, 2010): Role or influence of academic experience, influence of and/or connections with people and connections with Earth. Additionally, individual participant comments are well aligned the proposed framework by Kraft et al. (2011) for engaging geoscience students through the affective domain. We suggest that future studies should examine whether these findings are consistent across geologists from sub-domains that are less field-based and involve primarily modeling, or other computer- and lab

  5. Student research in criticality safety at the University of Arizona

    SciTech Connect

    Hetrick, D.L.

    1997-06-01

    A very brief progress report on four University of Arizona student projects is given. Improvements were made in simulations of power pulses in aqueous solutions, including the TWODANT model. TWODANT calculations were performed to investigate the effect of assembly shape on the expansion coefficient of reactivity for solutions. Preliminary calculations were made of critical heights for the Los Alamos SHEBA assembly. Calculations to support French experiments to measure temperature coefficients of dilute plutonium solutions confirmed feasibility.

  6. Dry critical experiments and analyses performed in support of the TOPAZ-2 safety program

    SciTech Connect

    Pelowitz, D.B.; Sapir, J.; Glushkov, E.S.; Ponomarev-Stepnoi, N.N.; Bubelev, V.G.; Kompanietz, G.B.; Krutov, A.M.; Polyakov, D.N.; Lobynstev, V.A.

    1995-01-20

    In December 1991, the Strategic Defense Initiative Organization decided to investigate the possibility of launching a Russian Topaz-2 space nuclear power system. Functional safety requirements developed for the Topaz mission mandated that the reactor remain subcritical when flooded and immersed in water. Initial experiments and analyses performed in Russia and the United States indicated that the reactor could potentially become supercritical in several water- or sand-immersion scenarios. Consequently, a series of critical experiments was performed on the Narciss M-II facility at the Kurchatov Institute to measure the reactivity effects of water and sand immersion, to quantify the effectiveness of reactor modifications proposed to preclude criticality, and to benchmark the calculational methods and nuclear data used in the Topaz-2 safety analyses. In this paper we describe the Narciss M-II experimental configurations along with the associated calculational models and methods. We also present and compare the measured and calculated results for the dry experimental configurations. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}

  7. Solution High-Energy Burst Assembly (SHEBA) results from subprompt critical experiments with uranyl fluoride fuel

    SciTech Connect

    Cappiello, C.C.; Butterfield, K.B.; Sanchez, R.G.

    1997-10-01

    The Solution High-Energy Burst Assembly (SHEBA) was originally constructed during 1980 and was designed to be a clean free-field geometry, right-circular, cylindrically symmetric critical assembly employing U(5%)O{sub 2}F{sub 2} solution as fuel. A second version of SHEBA, employing the same fuel but equipped with a fuel pump and shielding pit, was commissioned in 1993. This report includes data and operating experience for the 1993 SHEBA only. Solution-fueled benchmark work focused on the development of experimental measurements of the characterization of SHEBA; a summary of the results are given. A description of the system and the experimental results are given in some detail in the report. Experiments were designed to: (1) study the behavior of nuclear excursions in a low-enrichment solution, (2) evaluate accidental criticality alarm detectors for fuel-processing facilities, (3) provide radiation spectra and dose measurements to benchmark radiation transport calculations on a low-enrichment solution system similar to centrifuge enrichment plants, and (4) provide radiation fields to calibrate personnel dosimetry. 15 refs., 37 figs., 10 tabs.

  8. Critical periods after stroke study: translating animal stroke recovery experiments into a clinical trial

    PubMed Central

    Dromerick, Alexander W.; Edwardson, Matthew A.; Edwards, Dorothy F.; Giannetti, Margot L.; Barth, Jessica; Brady, Kathaleen P.; Chan, Evan; Tan, Ming T.; Tamboli, Irfan; Chia, Ruth; Orquiza, Michael; Padilla, Robert M.; Cheema, Amrita K.; Mapstone, Mark E.; Fiandaca, Massimo S.; Federoff, Howard J.; Newport, Elissa L.

    2015-01-01

    Introduction: Seven hundred ninety-five thousand Americans will have a stroke this year, and half will have a chronic hemiparesis. Substantial animal literature suggests that the mammalian brain has much potential to recover from acute injury using mechanisms of neuroplasticity, and that these mechanisms can be accessed using training paradigms and neurotransmitter manipulation. However, most of these findings have not been tested or confirmed in the rehabilitation setting, in large part because of the challenges in translating a conceptually straightforward laboratory experiment into a meaningful and rigorous clinical trial in humans. Through presentation of methods for a Phase II trial, we discuss these issues and describe our approach. Methods: In rodents there is compelling evidence for timing effects in rehabilitation; motor training delivered at certain times after stroke may be more effective than the same training delivered earlier or later, suggesting that there is a critical or sensitive period for strongest rehabilitation training effects. If analogous critical/sensitive periods can be identified after human stroke, then existing clinical resources can be better utilized to promote recovery. The Critical Periods after Stroke Study (CPASS) is a phase II randomized, controlled trial designed to explore whether such a sensitive period exists. We will randomize 64 persons to receive an additional 20 h of upper extremity therapy either immediately upon rehab admission, 2–3 months after stroke onset, 6 months after onset, or to an observation-only control group. The primary outcome measure will be the Action Research Arm Test (ARAT) at 1 year. Blood will be drawn at up to 3 time points for later biomarker studies. Conclusion: CPASS is an example of the translation of rodent motor recovery experiments into the clinical setting; data obtained from this single site randomized controlled trial will be used to finalize the design of a Phase III trial. PMID

  9. Cancer patients' experiences of nurses' behaviour and health promotion activities: a critical incident analysis.

    PubMed

    Björklund, M; Fridlund, B

    1999-12-01

    Patients with head and neck cancer report several disease- and health-related problems before, during and a long time after completed treatment. Nurses have an important role in educating/supporting these patients about/through the disease and treatment so that they can attain well-being. This study describes the cancer patients' experiences of nurses' behaviour in terms of critical incidents after nurses had given them care to promote health. The study had a qualitative, descriptive design and the method used was the critical incident technique. Twenty-one informants from the Nordic countries diagnosed with head and neck cancer were strategically selected. It was explained to the informants what a critical incident implies before the interviews took place; this was defined as a major event of great importance, an incident, which the informants still remember, due to its great importance for the outcome of their health and well-being. The nurses' behaviour was examined, and critical incidents were involved in 208 cases-150 positive and 58 negative ones-the number of incidents varying between three and 20 per informant. The nurses' health promotion activities or lack of such activities based on the patients' disease, treatment and symptoms, consisted of informing and instructing the patients as well as enabling their participation. Personal consideration and the nurses' cognisance, knowledge, competence, solicitude, demeanour and statements of understanding were found to be important. Continuous health promotion nursing interventions were of considerable value for the majority of this group of cancer patients. Oncology nurses could reconfirm and update the care of head and neck cancer patients by including health promotion activities in individual care plans. By more frequent use of health promotion models, such as the empowerment model, the nurses could identify and focus on those individuals who needed to alter their life-style as well as tailor their approach

  10. Experiences of fathering a baby admitted to neonatal intensive care: a critical gender analysis.

    PubMed

    Deeney, Kathleen; Lohan, Maria; Spence, Dale; Parkes, Jackie

    2012-09-01

    More fathers than ever before attend at the birth of their child and, internationally, there is a palpable pressure on maternity and neonatal services to include and engage with fathers. It is, thus, more important than ever to understand how fathers experience reproductive and neonatal health services and to understand how fathers can be successfully accommodated in these environments alongside their partners. In this paper we advance a theoretical framework for re-thinking fatherhood and health services approaches to fatherhood based on Critical Studies on Men (CSM). We illustrate the importance of this feminist informed theoretical approach to understanding the gendered experiences of fathers in a Neonatal Intensive Care Unit (NICU) setting in Northern Ireland. Using a longitudinal follow-up research design, with two data collection points, a total of 39 in-depth semi-structured interviews was conducted with 21 fathers of infants admitted to the NICU between August 2008 and December 2009. The findings demonstrate: (i) how men are forging new gendered identities around the birth of their baby but, over time, acknowledge women as the primary caregivers; (ii) how social class is a key determinant of men's ability to enact hegemonic forms of 'involved fatherhood' in the NICU, and; (iii) how men also encounter resistance from their partners and health professionals in challenging a gender order which associates women with the competent care of infants. An understanding of these gendered experiences operating at both individual and structural levels is critical to leading change for the inclusion of fathers as equal parents in healthcare settings. PMID:22694990

  11. The GUINEVERE experiment: First PNS measurements in a lead moderated sub-critical fast core

    SciTech Connect

    Thyebault, H. E.; Billebaud, A.; Chabod, S.; Lecolley, F. R.; Lecouey, J. L.; Lehaut, G.; Marie, N.; Ban, G.

    2012-07-01

    The GUINEVERE (Generation of Uninterrupted Intense Neutrons at the lead Venus Reactor) experimental program is dedicated to the study of Accelerator Driven System reactivity monitoring. It was partly carried out within the EUROTRANS integrated project (EURATOM FP6). GUINEVERE consists in coupling the fast core of the VENUS-F reactor (SCK-CEN, Mol (Belgium)), composed of enriched uranium and solid lead, with a T(d,n) neutron source provided by the GENEPI-3C deuteron accelerator. This neutron source can be operated in several modes: pulsed mode, continuous mode and also continuous mode with short beam interruptions (the so called 'beam trips'). In the past, the key questions of the reactivity control and monitoring in a subcritical system were studied in the MUSE experiments (1998-2004). These experiments highlighted the difficulty to determine precisely the reactivity with a single technique. This led to investigate a new strategy which is based on the combination of the relative reactivity monitoring via the core power to beam current relationship with absolute reactivity cross-checks during programmed beam interruptions. Consequently, to determine the reactivity, several dynamical techniques of reactivity determination have to be compared. In addition, their accuracy for absolute reactivity determination must be evaluated using a reference reactivity determination technique (from a critical state: rod drop and MSM measurements). The first sub-critical configuration which was studied was around k{sub eff} = 0.96 (SCI). Pulsed Neutron Source experiments (PNS) were carried out. The neutron population decrease was measured using fission chambers in different locations inside the core and the reflector. Neutron population time decrease was analyzed using fitting techniques and the Area Method Results obtained for the SCI reactivity will be shown, discussed and compared to the reference value given by the MSM method. (authors)

  12. Star of Lima - Overview and optical diagnostics of a barium Alfven critical velocity experiment

    NASA Technical Reports Server (NTRS)

    Wescott, E. M.; Stenbaek-Nielsen, H. C.; Hallinan, T.; Foeppl, H.; Valenzuela, A.

    1986-01-01

    The Alfven critical velocity mechanism for ionization of a neutral gas streaming across the magnetic field has been demonstrated in laboratory experiments. In March 1983, two rocket-borne experiments with Ba and Sr tested the effect in the wall-less laboratory of space from Punto Lobos, Peru, near 430 km altitude. 'Star of Lima' used a conical Ba shaped charge aimed at an instrument payload about 2 km away. Because of rocket overperformance the detonation occurred in partial sunlight, so that less than 21.6 percent of the ionizing UV was present. Particle and field measurements indicate the production of hot electrons and waves in the energy and frequency range that are respectively predicted to produce a cascade of ionization by the Alfven mechanism. However, the ionization fluxes and wave energy density did not reach cascade levels, and optical observations indicate that only 2.5 to 5 x 10 to the 20th Ba ions were produced. A substantial portion and perhaps all of the ionization could have been produced by solar UV. The failure of the Alfven process in this experiment is not well understood.

  13. Optical observations on the CRIT-II Critical Ionization Velocity Experiment

    NASA Technical Reports Server (NTRS)

    Stenbaek-Nielsen, H. C.; Wescott, E. M.; Haerendel, G.; Valenzuela, A.

    1990-01-01

    A rocket borne Critical Ionization Velocity (CIV0 experiment was carried out from Wallops Island at dusk on May 4, 1989. Two barium shaped charges were released below the solar terminator (to prevent photoionization) at altitudes near 400 km. The ambient ionospheric electron density was 50,000/cu cm. The neutral barium jet was directed upward and at an angle of nominally 45 degrees to B which gives approximately 3 x 10 to the 23rd neutrals with super critical velocity. Ions created by a CIV process in the region of the neutral jet would travel up along B into sunlight where they can be detected optically. Well defined ion clouds (max. brightness 750 R) were observed in both releases. An ionization rate of 0.8 percent/sec (125 sec ionization time constant) can account for the observed ion cloud near the release field line, but the ionization rate falls off with increasing distance from the release. It is concluded that a CIV process was present in the neutral jet out to about 50 km from the release, which is significantly further than allowed by current theories.

  14. New directions for critical internet health studies: representing cancer experience on the web.

    PubMed

    Seale, Clive

    2005-05-01

    Studies of health representations on the internet have been preoccupied with the assessment of their (medically-defined) accuracy and quality. This contrasts with studies of health representations in 'old' media, where critical sociological analyses are common. Medical sociologists have been concerned to establish the potential of web information in transforming professional-client relations. A case study of breast and prostate cancer web sites provides evidence of the increasing convergence of the 'new' medium of the internet and old media such as newspapers and television. Large institutions are now consolidating their presence on the web so that users experience increasingly similar messages across media platforms. Search engines and links to the web from old media sources direct people to heavily resourced, mainstream health sites where, in the case of cancer, representations of gender are strikingly similar to those found in studies of old media sources. The media convergence thesis contrasts with earlier celebrations of the internet as a new medium that would promote a diversity of perspectives on health. Using existing methods for analysing media texts and developing new methods where appropriate, sociologists and media analysts interested in health need to develop more critical perspectives on this important new medium.

  15. Analysis of selected critical experiments using ENDF/B-IV and ENDF/B-V data

    NASA Astrophysics Data System (ADS)

    Singh, U. N.; Rec, J. R.; Jonsson, A.

    1981-10-01

    Selected critical experiments - TRX 1 & 2 (U metal; BNL 1, 2, 3 (ThO2/U-233); and B & W TUPE 15B (ThO2/U-235) - were analyzed using ENDF/B-V data, and the results were compared to the measured parameters and to values obtained using ENDF/B-IV. Calculations were performed with DIT, an integral transport assembly design code. A heterogeneous cell calculation in 85 energy groups was performed for each configuration. Leakage was accounted for through B-1 calculation using the measured bucklings. Overall, ENDF/B-V data have been found to improve the agreement with experimental results with the exception of the TUPE 15B core. However, the changes in the capture cross sections of U-238 (epithermal) and Th-232 do not fully resolve the long-standing differences with the measurements.

  16. Analyzing the thermionic reactor critical experiments. [thermal spectrum of uranium 235 core

    NASA Technical Reports Server (NTRS)

    Niederauer, G. F.

    1973-01-01

    The Thermionic Reactor Critical Experiments (TRCE) consisted of fast spectrum highly enriched U-235 cores reflected by different thicknesses of beryllium or beryllium oxide with a transition zone of stainless steel between the core and reflector. The mixed fast-thermal spectrum at the core reflector interface region poses a difficult neutron transport calculation. Calculations of TRCE using ENDF/B fast spectrum data and GATHER library thermal spectrum data agreed within about 1 percent for the multiplication factor and within 6 to 8 percent for the power peaks. Use of GAM library fast spectrum data yielded larger deviations. The results were obtained from DOT R Theta calculations with leakage cross sections, by region and by group, extracted from DOT RZ calculations. Delineation of the power peaks required extraordinarily fine mesh size at the core reflector interface.

  17. Water/sand flooded and immersed critical experiment and analysis performed in support of the TOPAZ-II Safety Program

    SciTech Connect

    Glushkov, E.S.; Ponomarev-Stepnoi, N.N.; Bubelev, V.G.; Garin, V.P.; Gomin, E.A.; Kompanietz, G.V.; Krutoy, A.M.; Lobynstev, V.A.; Maiorov, L.V.; Polyakov, D.N.

    1994-11-01

    Presented is a brief description of the Narciss-M2 critical assemblies, which simulate accidental water/wet-sand immersion of the TOPAZ-II reactor as well as water-flooding of core cavities. Experimental results obtained from these critical assemblies, including experiments with several fuel elements removed from the core, are shown. These configurations with several extracted fuel elements simulate a proposed fuel-out anticriticality-device modification to the TOPAZ-II reactor. Preliminary computational analysis of these experiments using the Monte Carlo neutron-transport method is outlined. Nuclear criticality safety of the TOPAZ-II reactor with an incorporated anticriticality unit is demonstrated.

  18. Critical Race Media Projects: Counterstories and Praxis (Re)Claim Chicana/o Experiences

    ERIC Educational Resources Information Center

    Alemán, Sonya M.; Alemán, Enrique, Jr.

    2016-01-01

    This article maps out two critical race media projects -- a documentary and a Chicana/o-centric student newspaper--developed by Chicana/o scholars seeking to fulfilll the promise of praxis hailed by critical race theorists. Fortified and guided by the quintessential tenets of critical race theory and Latino critical race theory, these critical…

  19. Occurrences at Los Alamos National Laboratory: What can they tell us?

    SciTech Connect

    Richard A. Reichelt; A. Jeffery Eichorst; Marc E. Clay; Rita J. Henins; Judith D. DeHaven; Richard J. Brake

    2000-03-01

    The authors analyzed the evolution of institutional and facility response to groups of abnormal incidents at Los Alamos National Laboratory (LANL). The analysis is divided into three stages: (1) the LANL response to severe accidents from 1994 to 1996, (2) the LANL response to facility-specific clusters of low-consequence incidents from 1997 to 1999, and (3) the ongoing development of and response to a Laboratory-wide trending and analysis program. The first stage is characterized by five severe accidents at LANL--a shooting fatality, a forklift accident, two electrical shock incidents, and an explosion in a nuclear facility. Each accident caused LANL and the Department of Energy (DOE) to launch in-depth investigations. A recurrent theme of the investigations was the failure of LANL and DOE to identify and act on precursor or low-consequence events that preceded the severe accidents. The second stage is characterized by LANL response to precursor or low-consequence incidents over a two-year period. In this stage, the Chemistry and Metallurgy Research Facility, the Los Alamos Critical Experiments Facility, and the Los Alamos Neutron Science Center responded to an increase in low-consequence events by standing down their facilities. During the restart process, each facility collectively analyzed the low-consequence events and developed systemic corrective actions. The third stage is characterized by the development of a Laboratory-wide trending and analysis program, which involves proactive division-level analysis of incidents and development of systemic actions. The authors conclude that, while the stages show an encouraging evolution, the facility standdowns and restarts are overly costly and that the institutional trending and analysis program is underutilized. The authors therefore recommend the implementation of an institutional, mentored program of trending and analysis that identifies clusters of related low-consequence events, analyzes those events, and

  20. Sedimentation equilibria in polydisperse ferrofluids: critical comparisons between experiment, theory, and computer simulation.

    PubMed

    Elfimova, Ekaterina A; Ivanov, Alexey O; Lakhtina, Ekaterina V; Pshenichnikov, Alexander F; Camp, Philip J

    2016-05-14

    The sedimentation equilibrium of dipolar particles in a ferrofluid is studied using experiment, theory, and computer simulation. A theory of the particle-concentration profile in a dipolar hard-sphere fluid is developed, based on the local-density approximation and accurate expressions from a recently introduced logarithmic free energy approach. The theory is tested critically against Monte Carlo simulation results for monodisperse and bidisperse dipolar hard-sphere fluids in homogeneous gravitational fields. In the monodisperse case, the theory is very accurate over broad ranges of gravitational field strength, volume fraction, and dipolar coupling constant. In the bidisperse case, with realistic dipolar coupling constants and compositions, the theory is excellent at low volume fraction, but is slightly inaccurate at high volume fraction in that it does not capture a maximum in the small-particle concentration profile seen in simulations. Possible reasons for this are put forward. Experimental measurements of the magnetic-susceptibility profile in a real ferrofluid are then analysed using the theory. The concentration profile is linked to the susceptibility profile using the second-order modified mean-field theory. It is shown that the experimental results are not consistent with the sample being monodisperse. By introducing polydispersity in the simplest possible way, namely by assuming the system is a binary mixture, almost perfect agreement between theory and experiment is achieved.

  1. Sedimentation equilibria in polydisperse ferrofluids: critical comparisons between experiment, theory, and computer simulation.

    PubMed

    Elfimova, Ekaterina A; Ivanov, Alexey O; Lakhtina, Ekaterina V; Pshenichnikov, Alexander F; Camp, Philip J

    2016-05-14

    The sedimentation equilibrium of dipolar particles in a ferrofluid is studied using experiment, theory, and computer simulation. A theory of the particle-concentration profile in a dipolar hard-sphere fluid is developed, based on the local-density approximation and accurate expressions from a recently introduced logarithmic free energy approach. The theory is tested critically against Monte Carlo simulation results for monodisperse and bidisperse dipolar hard-sphere fluids in homogeneous gravitational fields. In the monodisperse case, the theory is very accurate over broad ranges of gravitational field strength, volume fraction, and dipolar coupling constant. In the bidisperse case, with realistic dipolar coupling constants and compositions, the theory is excellent at low volume fraction, but is slightly inaccurate at high volume fraction in that it does not capture a maximum in the small-particle concentration profile seen in simulations. Possible reasons for this are put forward. Experimental measurements of the magnetic-susceptibility profile in a real ferrofluid are then analysed using the theory. The concentration profile is linked to the susceptibility profile using the second-order modified mean-field theory. It is shown that the experimental results are not consistent with the sample being monodisperse. By introducing polydispersity in the simplest possible way, namely by assuming the system is a binary mixture, almost perfect agreement between theory and experiment is achieved. PMID:27042815

  2. Creating an Alternate Reality: Critical, Creative, and Empathic Thinking Generated in the "Global Village Playground" Capstone Experience

    ERIC Educational Resources Information Center

    Dondlinger, Mary Jo; Wilson, Douglas A.

    2012-01-01

    The "Global Village Playground" ("GVP") was a capstone learning experience designed to address institutional assessment needs while providing an integrated and authentic learning experience for students aimed at fostering critical and creative thinking. In the "GVP", students work on simulated and real-world problems as a design team tasked with…

  3. On the evaluation of pebble bed reactor critical experiments using the PEBBED code

    SciTech Connect

    Hans D. Gougar; R. Sonat Sen

    2001-10-01

    The PEBBED pebble bed reactor fuel management code under development at the Idaho National Laboratory is designed for rapid design and analysis of pebble bed high temperature reactors (PBRs). Embedded within the code are the THERMIX-KONVEK thermal fluid solver and the COMBINE-7 spectrum generation code for inline cross section homogenization. Because 1D symmetry can be found at each stage of core heterogeneity; spherical at TRISO and pebble levels, and cylindrical at the control rod and core levels, the 1-D transport capability of ANISN is assumed to be sufficient in most cases for generating flux solutions for cross section homogenization. Furthermore, it is fast enough to be executed during the analysis or the equilibrium core. Multi-group diffusion-based design codes such as PEBBED and VSOP are not expected to yield the accuracy and resolution of continuous energy Monte Carlo codes for evaluation of critical experiments. Nonetheless, if the preparation of multigroup cross sections can adequately capture the physics of the mixing of PBR fuel elements and leakage from the core, reasonable results may be obtained. In this paper, results of the application of PEBBED to two critical experiments (HTR Proteus and HTR-10) and associated computational models are presented. The embedded 1-D transport solver is shown to capture the double heterogeneity of the pebble fuel in unit cell calculations. Eigenvalue calculations of a whole core are more challenging, particularly if the boron concentration is uncertain. The sensitivity of major safety parameters to variations in modeling assumptions, however, is shown to be minimal. The embedded transport solver can also be used to obtain control rod worths but only with adjustment of the local spectrum. Results are compared to those of other codes as well as Core 4 of the HTR-Proteus experiment which contains partially inserted rods. They indicate the need for a reference solution to adjust the radius of the graphite in the

  4. Nuclear accident dosimetry studies at Los Alamos National Laboratory

    SciTech Connect

    Casson, W.H.; Buhl, T.E.; Upp, D.L.

    1995-12-01

    Two critical assemblies have been characterized at the Los Alamos Critical Experiments Facility (LACEF) for use in testing nuclear accident dosimeters and related devices. These device, Godiva IV and SHEBA II, have very different characteristics in both operation and emitted neutron energy spectra. The Godiva assembly is a bare metal fast burst device with a hard spectrum. This spectrum can be modified by use of several shields including steel, concrete, and plexiglas. The modified spectra vary in both average neutron energy and in the specific distribution of the neutron energies in the intermediate energy range. This makes for a very favorable test arrangement as the response ratios between different activation foils used in accident dosimeters are significantly altered such as the ratio between gold, copper, and sulfur elements. The SHEBA device is a solution assembly which has both a slow ramp and decay period and a much softer spectrum. The uncertainly introduced in the response of fast decay foils such as indium can therefore be evaluated into the test results. The neutron energy spectrum for each configuration was measured during low power operations with a multisphere system. These measurements were extended to high dose pulsed operation by use of TLDs moderated TLDs, and special activation techniques. The assemblies were used in the testing of several accident dosimetry devices in studies modeled after the Nuclear Accident Dosimetry Studies that were conducted at Oak Ridge National Laboratory for about 25 years using the Health Physics Research Reactor. It is our intention to conduct these studies approximately annually for the evaluation of the nuclear accident dosimeter systems currently in use within the DOE, alternative systems used internationally, and new dosimeter designs being developed or considered for field application. Participation in selected studies will be open to all participants.

  5. Nonlinear Upshift of Trapped Electron Mode Critical Density Gradient: Simulation and Experiment

    NASA Astrophysics Data System (ADS)

    Ernst, D. R.

    2012-10-01

    A new nonlinear critical density gradient for pure trapped electron mode (TEM) turbulence increases strongly with collisionality, saturating at several times the linear threshold. The nonlinear TEM threshold appears to limit the density gradient in new experiments subjecting Alcator C-Mod internal transport barriers to modulated radio-frequency heating. Gyrokinetic simulations show the nonlinear upshift of the TEM critical density gradient is associated with long-lived zonal flow dominated states [1]. This introduces a strong temperature dependence that allows external RF heating to control TEM turbulent transport. During pulsed on-axis heating of ITB discharges, core electron temperature modulations of 50% were produced. Bursts of line-integrated density fluctuations, observed on phase contrast imaging, closely follow modulations of core electron temperature inside the ITB foot. Multiple edge fluctuation measurements show the edge response to modulated heating is out of phase with the core response. A new limit cycle stability diagram shows the density gradient appears to be clamped during on-axis heating by the nonlinear TEM critical density gradient, rather than by the much lower linear threshold. Fluctuation wavelength spectra will be quantitatively compared with nonlinear TRINITY/GS2 gyrokinetic transport simulations, using an improved synthetic diagnostic. In related work, we are implementing the first gyrokinetic exact linearized Fokker Planck collision operator [2]. Initial results show short wavelength TEMs are fully stabilized by finite-gyroradius collisional effects for realistic collisionalities. The nonlinear TEM threshold and its collisionality dependence may impact predictions of density peaking based on quasilinear theory, which excludes zonal flows.[4pt] In collaboration with M. Churchill, A. Dominguez, C. L. Fiore, Y. Podpaly, M. L. Reinke, J. Rice, J. L. Terry, N. Tsujii, M. A. Barnes, I. Bespamyatnov, R. Granetz, M. Greenwald, A. Hubbard, J. W

  6. Recent developments in the Los Alamos radiation transport code system

    SciTech Connect

    Forster, R.A.; Parsons, K.

    1997-06-01

    A brief progress report on updates to the Los Alamos Radiation Transport Code System (LARTCS) for solving criticality and fixed-source problems is provided. LARTCS integrates the Diffusion Accelerated Neutral Transport (DANT) discrete ordinates codes with the Monte Carlo N-Particle (MCNP) code. The LARCTS code is being developed with a graphical user interface for problem setup and analysis. Progress in the DANT system for criticality applications include a two-dimensional module which can be linked to a mesh-generation code and a faster iteration scheme. Updates to MCNP Version 4A allow statistical checks of calculated Monte Carlo results.

  7. Critical Media Literacy and Popular Film: Experiences of Teaching and Learning in a Graduate Class

    ERIC Educational Resources Information Center

    Stuckey, Heather; Kring, Kelly

    2007-01-01

    This chapter describes the use of popular film and semiotics for the development of critical media literacy in a graduate-level education course entitled "Pop Culture as Pedagogy: The Role of Entertainment Media in Teaching for Critical Consciousness and Critical Media Literacy." The course focused on analysis of different forms of pop culture,…

  8. Why Deuterium+Au was the critical control experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Gyulassy, Miklos

    2003-10-01

    One of the striking discoveries at RHIC was the strong (factor of 4-5) suppression of high pT pions above 4 GeV/c in central Au+Au at 200 AGeV. In addition the data reveal an evolution from di-jet correlations in peripheral collisions to mono-jet production in central collisions. Two paradigms existed prior to the new D+Au data proporting to explain the same jet quenching pattern. One is based on the formation of an opaque Quark-Gluon Plasma [1]. The other is based on initial state gluon shadowing in the Color Glass Condensate model for the nuclear wavefunction [2]. I review both paradigms and how the D+Au reaction provides the critical control experiment to decide which is closer to reality under RHIC conditions. I conclude that if the preliminary d+Au data are confirmed, then a QGP was in fact formed in central Au+Au at RHIC. References: [1] M. Gyulassy, Ivan Vitev, Xin-Nian Wang, Ben-Wei Zhang nucl-th/0302077 and refs. therein. [2] Edmond Iancu, Raju Venugopalan hep-ph/0303204 and refs. therein.

  9. K/sub infinity/-meter concept verified via subcritical-critical TRIGA experiments

    SciTech Connect

    Ocampo Mansilla, H.

    1983-01-01

    This work presents a technique for building a device to measure the k/sub infinity/ of a spent nuclear fuel assembly discharged from the core of a nuclear power plant. The device, called a k/sub infinity/-meter, consists of a cross-shaped subcritical assembly, two artificial neutron sources, and two separate neutron counting systems. The central position of the subcritical assembly is used to measure k/sub infinity/ of the spent fuel assembly. The initial subcritical assembly is calibrated to determine its k/sub eff/ and verify the assigned k/sub infinity/ of a selected fuel assembly placed in the central position. Count rates are taken with the fuel assembly of known k/sub infinity/'s placed in the central position and then repeated with a fuel assembly of unknown k/sub infinity/ placed in the central position. The count rate ratio of the unknown fuel assembly to the known fuel assembly is used to determine the k/sub infinity/ of the unknown fuel assembly. The k/sub infinity/ of the unknown fuel assembly is represented as a polynomial function of the count rate ratios. The coefficients of the polynomial equation are determined using the neutronic codes LEOPARD and EXTERMINATOR-II. The analytical approach has been validated by performing several subcritical/critical experiments, using the Penn State Breazeale TRIGA Reactor (PSBR), and comparing the experimental results with the calculations.

  10. Critical Heat Flux Experiments on the Reactor Vessel Wall Using 2-D Slice Test Section

    SciTech Connect

    Jeong, Yong Hoon; Chang, Soon Heung; Baek, Won-Pil

    2005-11-15

    The critical heat flux (CHF) on the reactor vessel outer wall was measured using the two-dimensional slice test section. The radius and the channel area of the test section were 2.5 m and 10 cm x 15 cm, respectively. The flow channel area and the heater width were smaller than those of the ULPU experiments, but the radius was greater than that of the ULPU. The CHF data under the inlet subcooling of 2 to 25 deg. C and the mass flux 0 to 300 kg/m{sup 2}.s had been acquired. The measured CHF value was generally slightly lower than that of the ULPU. The difference possibly comes from the difference of the test section material and the thickness. However, the general trend of CHF according to the mass flux was similar with that of the ULPU. The experimental CHF data were compared with the predicted values by SULTAN correlation. The SULTAN correlation predicted well this study's data only for the mass flux higher than 200 kg/m{sup 2}.s, and for the exit quality lower than 0.05. The local condition-based correlation was developed, and it showed good prediction capability for broad quality (-0.01 to 0.5) and mass flux (<300 kg/m{sup 2}.s) conditions with a root-mean-square error of 2.4%. There were increases in the CHF with trisodium phosphate-added water.

  11. Determination of the Critical Micelle Concentration of Cationic Surfactants: An Undergraduate Experiment

    NASA Astrophysics Data System (ADS)

    Huang, Xirong; Yang, Jinghe; Zhang, Wenjuan; Zhang, Zhenyu; An, Zesheng

    1999-01-01

    A novel method based on the catalytic effect of micelles exerted by cetyltrimethylammonium bromide (CTAB) and cetylpyridinium bromide (CPB), respectively, on the indicator reaction between H2O2 and bromopyrogallol red (BPR), a triphenylmethane dye, was developed for undergraduates to determine the critical micelle concentration (cmc) of CTAB and CPB. The indicator reaction was monitored by a fixed-time kinetic-spectrophotometric technique. Under the experimental conditions the cmc values of CTAB and CPB were (4.8 ± 0.3) x 10-4 mol/L and (4.5 ± 0.3) x 10-4mol/L, which were close to the literature values of 9.2 x 10-4 mol/L and 9.0 x 10-4 mol/L, respectively. Detailed discussion on the selection of experimental conditions was made to minimize the effect of electrolytes on the cmc's of surfactants and to maintain the high accuracy of the experimental data. As an undergraduate physicochemical laboratory experiment the present method had several attractive features. The procedure is simple and easy to perform, does not require special equipment, and does not need expensive or toxic reagents. In addition, it is a versatile method that can be applied to a wide variety of both anionic and cationic surfactants.

  12. Experience report: Using formal methods for requirements analysis of critical spacecraft software

    NASA Technical Reports Server (NTRS)

    Lutz, Robyn R.; Ampo, Yoko

    1994-01-01

    Formal specification and analysis of requirements continues to gain support as a method for producing more reliable software. However, the introduction of formal methods to a large software project is difficult, due in part to the unfamiliarity of the specification languages and the lack of graphics. This paper reports results of an investigation into the effectiveness of formal methods as an aid to the requirements analysis of critical, system-level fault-protection software on a spacecraft currently under development. Our experience indicates that formal specification and analysis can enhance the accuracy of the requirements and add assurance prior to design development in this domain. The work described here is part of a larger, NASA-funded research project whose purpose is to use formal-methods techniques to improve the quality of software in space applications. The demonstration project described here is part of the effort to evaluate experimentally the effectiveness of supplementing traditional engineering approaches to requirements specification with the more rigorous specification and analysis available with formal methods.

  13. Spacelab experiment definition study on phase transition and critical phenomena in fluids: Interim report on experimental justification

    NASA Technical Reports Server (NTRS)

    Moldover, M. R.; Hocken, M. R.; Gammon, R. W.; Sengers, J. V.

    1976-01-01

    Pure fluids and fluid mixtures near critical points are identified and are related to the progress of several disciplines. Consideration is given to thermodynamic properties, transport properties, and the complex nonlinear phenomena which occur when fluids undergo phase transitions in the critical region. The distinction is made between practical limits which may be extended by advances in technology and intrinsic ones which arise from the modification of fluid properties by the earth's gravitational field. The kinds of experiments near critical points which could best exploit the low gravity environment of an orbiting laboratory are identified. These include studies of the index of refraction, constant volume specific heat, and phase separation.

  14. Criticality experiments with mixed plutonium and uranium nitrate solution at a plutonium fraction of 0.4 in slab geometry

    SciTech Connect

    Pohl, B.A.; Keeton, S.C.

    1997-09-01

    R. C. Lloyd of PNL has completed and published a series of critical experiments with mixed plutonium- uranium nitrate solutions (Reference 1). This series of critical experiments was part of an extensive program jointly sponsored by the U. S. Department of Energy (DOE) and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan and was carried out in the mid-1980`s. The experiments evaluated here (published as Report PNL-6327) were performed with mixed plutonium- uranium nitrate solution in a variable thickness slab tank with two 106.7 cm square sides and a width that could be varied from 7.6 to 22.8 cm. The objective of these experiments was to obtain experimental data to permit the validation of computer codes for criticality calculations and of cross-section data to minimize the uncertainties inherent therein, so that facility safety, efficiency, and reliability could be enhanced. The concentrations of the solution were about 105, 293, and 435 g(Pu+U)/liter with a ratio of plutonium to total heavy metal (plutonium plus uranium) of about 0. 40 for all eight experiments. Four measurements were made with a water reflector, and four with no reflector. Following the publication of the initial PNL reports, considerable effort was devoted to an extensive reevaluation of this series of experiments by a collaboration of researchers from ORNL, PNL, and PNC (Reference 2). Their work resulted in a more accurate description of the ``as built`` hardware configuration and the materials specifications. For the evaluations in this report, the data published in Reference 2 by Smolen et al. is selected to supersede the original PNL report. Eight experiments have been evaluated and seven (063, 064, 071, 072, 074, 075, and 076) provide benchmark criticality data. Experiment 073 could not achieve criticality within vessel height limitations.

  15. Critical Components of a Successful Undergraduate Research Experience in the Geosciences for Minority Students

    NASA Astrophysics Data System (ADS)

    Liou-Mark, J.; Blake, R.; Chukuigwe, C.

    2013-12-01

    For the past five years, the New York City College of Technology has administered a successful National Science Foundation (NSF) Research Experience for Undergraduates (REU) program. The program provides rich, substantive, academic and life-transformative STEM educational experiences for students who would otherwise not pursue STEM education altogether or would not pursue STEM education through to the graduate school level. The REU Scholars are provided with an opportunity to conduct intensive satellite and ground-based remote sensing research at the National Oceanic and Atmospheric Administration Cooperative Remote Sensing Science and Technology Center (NOAA-CREST). Candidates for the program are recruited from the City University of New York's twenty-three separate campuses. These students engage in a research experience that spans the summer and the fall and spring semesters. Eighty-four percent (84%) of the program participants are underrepresented minorities in STEM, and they are involved in a plethora of undergraduate research best practice activities that include: training courses in MATLAB programming, Geographic Information Systems, and Remote Sensing; workshops in Research Ethics, Scientific Writing, and Oral and Poster Research Presentations; national, regional, and local conference presentations; graduate school support; and geoscience exposure events at national laboratories, agencies, and research facilities. To enhance their success in the program, the REU Scholars are also provided with a comprehensive series of safety nets that include a multi-tiered mentoring design specifically to address critical issues faced by this diverse population. Since the inception of the REU program in 2008, a total of 61 undergraduate students have finished or are continuing with their research or are pursuing their STEM endeavors. All the REU Scholars conducted individual satellite and ground-based remote sensing research projects that ranged from the study of

  16. Trauma-exposed firefighters: relationships among posttraumatic growth, posttraumatic stress, resource availability, coping and critical incident stress debriefing experience.

    PubMed

    Sattler, David N; Boyd, Bill; Kirsch, Julie

    2014-12-01

    This project examines protective factors associated with resilience/posttraumatic growth and risk factors associated with posttraumatic stress among firefighters exposed to critical incidents. The participants were 286 (257 men and 29 women) volunteer and paid firefighters in Whatcom County, Washington. Participants completed an anonymous survey asking about demographics, critical incident exposure, posttraumatic stress symptoms, posttraumatic growth, resource availability, coping, occupational stress and critical incident stress debriefing experience. Most participants had significant critical incident exposure, and about half had attended critical incident stress debriefing sessions. Posttraumatic growth was associated with being female, critical incident exposure, critical incident stress debriefing attendance, posttraumatic stress symptoms (negative association), occupational support, occupation satisfaction, occupational effort, problem-focused coping, emotion-focused coping and personal characteristic resources. Posttraumatic stress symptoms were positively associated with years of firefighting, burnout, occupational effort and disengagement coping and negatively associated with critical incident stress debriefing attendance, posttraumatic growth, social support, internal locus of control, personal characteristic resources, energy resources and condition resources. The findings support conservation of resources stress theory and show that the maintenance and acquisition of resources can offset losses and facilitate resilience/posttraumatic growth. Implications of the findings for enhancing firefighter resources, facilitating resilience and minimizing occupational stressors are discussed.

  17. Trauma-exposed firefighters: relationships among posttraumatic growth, posttraumatic stress, resource availability, coping and critical incident stress debriefing experience.

    PubMed

    Sattler, David N; Boyd, Bill; Kirsch, Julie

    2014-12-01

    This project examines protective factors associated with resilience/posttraumatic growth and risk factors associated with posttraumatic stress among firefighters exposed to critical incidents. The participants were 286 (257 men and 29 women) volunteer and paid firefighters in Whatcom County, Washington. Participants completed an anonymous survey asking about demographics, critical incident exposure, posttraumatic stress symptoms, posttraumatic growth, resource availability, coping, occupational stress and critical incident stress debriefing experience. Most participants had significant critical incident exposure, and about half had attended critical incident stress debriefing sessions. Posttraumatic growth was associated with being female, critical incident exposure, critical incident stress debriefing attendance, posttraumatic stress symptoms (negative association), occupational support, occupation satisfaction, occupational effort, problem-focused coping, emotion-focused coping and personal characteristic resources. Posttraumatic stress symptoms were positively associated with years of firefighting, burnout, occupational effort and disengagement coping and negatively associated with critical incident stress debriefing attendance, posttraumatic growth, social support, internal locus of control, personal characteristic resources, energy resources and condition resources. The findings support conservation of resources stress theory and show that the maintenance and acquisition of resources can offset losses and facilitate resilience/posttraumatic growth. Implications of the findings for enhancing firefighter resources, facilitating resilience and minimizing occupational stressors are discussed. PMID:25476961

  18. Early Experience with Racial Discrimination and Conduct Disorder as Predictors of Subsequent Drug Use: A Critical Period Hypothesis

    PubMed Central

    Gibbons, Frederick X.; Yeh, Hsiu-Chen; Gerrard, Meg; Cleveland, Michael J.; Cutrona, Carolyn; Simons, Ronald L.; Brody, Gene H.

    2007-01-01

    A critical period hypothesis linking early experiences with both racial discrimination and conduct disorder (CD) with subsequent drug use was examined in a panel of 889 African American adolescents (age 10.5 at Time 1) and their parents. Analyses indicated that these early experiences did predict use by the adolescents at Time 3--five years later. These relations were both direct and indirect, being mediated by an increase in affiliation with friends who were using drugs. The relations existed controlling for parents’ reports of their use, discrimination experiences, and their socioeconomic status (SES). The impact of these early experiences on African American families is discussed. PMID:17275213

  19. Results of the HPT-experiment critical adsorption on EURECA I

    NASA Astrophysics Data System (ADS)

    Thommes, M.; Findenegg, G. H.

    1995-08-01

    The adsorption behavior of a near-critical fluid (SF_6) on a finely dispersed graphitic adsorbent (graphitized carbon black, Vulcan 3-G) has been studied. The surface excess concentration Gamma was measured as a function of temperature along near-critical isochores using a volumetric apparatus housed in a high-precision thermostat (HPT). Five experimental runs (each extending over ca. 30 days) were performed on the EURECA I space platform to avoid gravitational effects on the near-critical bulk fluid. In addition, complementary tests involving systematic changes of the experimental conditions were also performed by sequences of telecommands to test the reliability of the results in the near-critical region. The EURECA results confirm a novel critical adsorption phenomenon, which is probably due to the colloidal state of the adsorbent and is termed critical depletion.

  20. Results of critical velocity experiments with barium, strontium, and calcium releases from CRRES satellite

    NASA Technical Reports Server (NTRS)

    Wescott, E. M.; Stenbaek-Nielsen, H. C.; Hampton, D. L.; Delamere, P. A.

    1994-01-01

    As part of the NASA Combined Release and Radiation Effects Satellite (CRRES) chemical release program in September 1990, two Ba and also one each Sr and Ca canisters of a boron-titanium thermite mixture, which vaporizes the element on ignition, were released near perigee after dusk in the South Pacific to study the critical velocity effect proposed by Alfven. The critical velocities of these three elements are 2.7, 3.5, and 5.4 km/s respectively, all well below the orbital velocity of 9.4 km/s. On September 10, 1990, a Sr and Ba pair (G-13, or critical ionization velocity (CIV) I) was released near Rarotonga at approximately 515 km altitude in a background electron density of 3.4 x 10(exp 6)/cu cm. On September 14, 1990, G-14 or CIV II released a Ca and Ba pair west of New Caledonia near 595 km at an electron density of 1.5 x 10(exp 6)/cu cm. Ions of all three elements were observed with low-light level imagers from two aircraft after they had transited up the magnetic field lines into the sunlight. Emissions from the spherically expanding neutral gas shells below the solar terminator, observed with cameras filtered for the Ba(+) ion line at 4554 A and also in unfiltered imagers for approximately 15 s after release, are probably due to excitation by hot electrons created in the CIV process. The ions created clearly lost much of their energy, which we now show can be explained by elastic collisions: Ba(+) + O. Inventories of the observed ions indicate yields of 0.15% and 1.84% for Ba in the first and second experiments, 0.02% for Sr and 0.27% for Ca. Ionization from all the releases continued along the satellite trajectory much longer (greater than 45 s) than expected for a CIV process. The ion production along the satellite track versus time typically shows a rapid rise to a peak in a few seconds followed by an exponential decrease to a level essentially constant rate. The characteristic distances for CIV I and II are 47 and 62 km, respectively. We interpret the

  1. Campus Climate and the Underrepresented Minority Engineering Student Experience: A Critical Race Study

    NASA Astrophysics Data System (ADS)

    Mayes, Terrance

    In the current technological era, the number of minorities in science, technology, engineering, and mathematics (STEM) is a crucial factor in predetermining the economic growth of the United States. Since the minority population is growing at much faster rates than the non-minority population, the lack of proportionate production of minority engineers poses a threat to the United States' ability to remain a global competitor in technological innovation. Sixty-three per cent (63%) of undergraduate students who enter engineering majors continue on to graduate in that major. The graduation rate, however, for African-American, Hispanic, and Native-American students in engineering is significantly lower at 39%. As this group represents only a small fraction of the annual student enrollment, engineering programs are graduating these minority groups at rates that are greatly disproportionate to United States demographics. Therefore, researchers are thoroughly investigating certain initiatives that promote academic success among underrepresented minority students in engineering. Colleges and universities have attempted to address the growing achievement gap between underrepresented minority and non-minority engineering students, predominately through various deficit-based interventions, focusing on the student's flaws and problems. As the pipeline for minorities in engineering continues to narrow, it begs the question of whether institutions are focusing on the right solutions to the problem. Critical Race Theory scholars argue that colleges and universities must address institutional climate issues around students, such as racism, microaggressions, and marginalization, before members of oppressed groups can truly succeed. This dissertation explored the unique experiences of underrepresented minority engineering students in a predominately White and Asian campus.

  2. Power Distribution Analysis for the ORNL High Flux Isotope Reactor Critical Experiment 3

    SciTech Connect

    Chandler, David; Primm, Trent; Maldonado, G Ivan

    2010-01-01

    The mission of the Reduced Enrichment for Research and Test Reactors Program is to minimize and, to the extent possible, eliminate the use of highly enriched uranium (HEU) in civilian nuclear applications by working to convert research and test reactors, as well as radioisotope production processes, to low-enriched uranium (LEU) fuel and targets. Oak Ridge National Laboratory (ORNL) is currently reviewing the design bases and key operating criteria including fuel operating parameters, enrichment-related safety analyses, fuel performance, and fuel fabrication in regard to converting the fuel of the High Flux Isotope Reactor (HFIR) from HEU to LEU. The purpose of this study is to validate Monte Carlo methods currently in use for conversion analyses. The methods have been validated for the prediction offlux values in the reactor target, reflector, and beam tubes, but this study focuses on the prediction of the power density profile in the core. Power distributions were calculated in the fuel elements of the HFIR, a research reactor at ORNL, via MCNP and were compared to experimentally obtained data. This study was performed to validate Monte Carlo methods for power density calculations and to observe biases. A current three-dimensional MCNP model was modified to replicate the 1965 HFIR Critical Experiment 3 (HFIRCE-3). In this experiment, the power profile was determined by counting the gamma activity at selected locations in the core. 'Foils' (chunks of fuel meat and clad) were punched out of the fuel elements in HFIRCE-3 following irradiation, and experimental relative power densities were obtained by measuring the activity of these foils and comparing each foil's activity to the activity of a normalizing foil. This analysis consisted of calculating corresponding activities by inserting volume tallies into the modified MCNP model to represent the punchings. The average fission density was calculated for each foil location and then normalized to the reference foil

  3. Promotion of critical thinking in e-learning: a qualitative study on the experiences of instructors and students

    PubMed Central

    Gharib, Mitra; Zolfaghari, Mitra; Mojtahedzadeh, Rita; Mohammadi, Aeen; Gharib, Atoosa

    2016-01-01

    Background With the increasing popularity of e-learning programs, educational stakeholders are attempting to promote critical thinking in the virtual education system. This study aimed to explore the experiences of both the instructors and the students about critical thinking promotion within the virtual education system. Methods This qualitative study recruited the instructors and students from four academic disciplines provided by the Virtual School of Tehran University of Medical Sciences (Tehran, Iran). All programs were master’s degree programs and utilized a blended (combination of e-learning and face to face) training. Semistructured interviews with the participants were used to collect data. Results The participants had a variety of experiences about how to promote critical thinking. These experiences were conceptualized in four main themes, namely, instructional design, educational leadership and management, local evidence, and belief systems. Conclusion The present study clarified the factors affecting critical thinking promotion in e-learning. Not only the instructors but also the educational designers and leaders can benefit from our findings to improve the quality of virtual education programs and promote critical thinking. PMID:27217807

  4. Enhancing Critical Thinking across the Undergraduate Experience: An Exemplar from Engineering

    ERIC Educational Resources Information Center

    Ralston, Patricia A.; Bays, Cathy L.

    2013-01-01

    Faculty in a large, urban school of engineering designed a longitudinal study to assess the critical thinking skills of undergraduate students as they progressed through the engineering program. The Paul-Elder critical thinking framework was used to design course assignments and develop a holistic assessment rubric. The curriculum was re-designed…

  5. Water/sand flooded and immersed critical experiment and analysis performed in support of the TOPAZ-II safety program

    SciTech Connect

    Glushkov, E.S.; Ponomarev-Stepnoi, N.N.; Bubelev, V.G.; Garin, V.P.; Gomin, E.A.; Kompanietz, G.V.; Krutov, A.M.; Lobynstev, V.A.; Maiorov, L.V.; Polyakov, D.N.; Chunyaev, E.I.; Marshall, A.C.; Sapir, J.L.; Pelowitz, D.B.

    1995-01-20

    Presented is a brief description of the Narciss-M2 critical assemblies, which simulate accidental water/wet-sand immersion of the TOPAZ-II reactor as well as water-flooding of core cavities. Experimental results obtained from these critical assemblies, including experiments with several fuel elements removed from the core, are shown. These configurations with several extracted fuel elements simulate a proposed fuel-out anticriticality-device modification to the TOPAZ-II reactor. Preliminary computational analysis of these experiments using the Monte Carlo neutron-transport method is outlined. Nuclear criticality safety of the TOPAZ-II reactor with an incorporated anticriticality unit is demonstrated. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}

  6. Diversity and Collegiate Experiences Affecting Self-Perceived Gains in Critical Thinking: Which Works, and Who Benefits?

    ERIC Educational Resources Information Center

    Cole, Darnell; Zhou, Ji

    2014-01-01

    This study is grounded in the theoretical and conceptual frameworks that postulate diversity and collegiate experiences as triggers for the cognitive disequilibrium that fosters critical thinking (CT). With the assumption that CT is both a general and a discipline-specific facility, this longitudinal, single-institution study of 447 students…

  7. Teaching Computers to Tell Learning Stories: Using Critical Narrative Theory to Frame Design and Evaluation Strategies for Online Educational Experiences

    ERIC Educational Resources Information Center

    Voithofer, Rick

    2004-01-01

    Through a critical analysis of Classroom Connect's Quest experiences from 1998-2002, this study provides a framework for using narrative theory to guide the design and evaluation of educational multimedia and online education. Narrative theory, derived from literary and media studies and influenced by cultural studies, offers numerous parallels to…

  8. Contemporary Theories of Oral Communication: A Collection of Abstracts, Critical Literature Reviews, and Experiments in the Study of Communication.

    ERIC Educational Resources Information Center

    Smith, Robert M., Ed.

    This booklet is a collection of abstracts, literature reviews, and reports on experiments in the communication field. Ninety abstracts from speech communication literature (1970-1977) are presented under the following categories: communication theory, research methodology, interpersonal communication, rhetorical theory and criticism, persuasion,…

  9. Contextualizing Asian American Education through Critical Race Theory: An Example of U.S. Pilipino College Student Experiences

    ERIC Educational Resources Information Center

    Buenavista, Tracy Lachica; Jayakumar, Uma M.; Misa-Escalante, Kimberly

    2009-01-01

    In this article, the authors offer a CRT (critical race theory) perspective of the prevailing representation of Asian Americans in higher education research and acknowledge the importance of recent studies that have begun to challenge notions of a monolithic Asian American educational experience through an examination of differences among Asian…

  10. Can Educators Make a Difference? Experimenting with, and Experiencing, Democracy in Education. Critical Constructions: Studies on Education and Society

    ERIC Educational Resources Information Center

    Carr, Paul R., Ed.; Zyngier, David, Ed.; Pruyn, Marc, Ed.

    2012-01-01

    As the title of this book suggests, how one understands, perceives and experiences democracy may have a significant effect on how he/she actually engages in, and with, democracy. Within the educational context, this is a key concern, and forms the basis of the research presented in this volume within a critical, comparative analysis. The Global…

  11. Los Alamos Science, Number 25 -- 1997: Celebrating the neutrino

    SciTech Connect

    Cooper, N.G.

    1997-12-31

    This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos.

  12. Assessment of Zero Power Critical Experiments and Needs for a Fission Surface Power System

    SciTech Connect

    Jim R Parry; John Darrell bess; Brad T. Rearden; Gary A. Harms

    2009-06-01

    The National Aeronautics and Space Administration (NASA) is providing funding to the Department of Energy (DOE) to assess, develop, and test nuclear technologies that could provide surface power to a lunar outpost. Sufficient testing of this fission surface power (FSP) system will need to be completed to enable a decision by NASA for flight development. The near-term goal for the FSP work is to conduct the minimum amount of testing needed to validate the system performance within an acceptable risk. This report attempts to assess the current modeling capabilities and quantify any bias associated with the modeling methods for designing the nuclear reactor. The baseline FSP system is a sodium-potassium (NaK) cooled, fast spectrum reactor with 93% 235U enriched HEU-O2 fuel, SS316 cladding, and beryllium reflectors with B4C control drums. The FSP is to produce approximately 40 kWe net power with a lifetime of at least 8 years at full power. A flight-ready FSP is to be ready for launch and deployment by 2020. Existing benchmarks from the International Criticality Safety Benchmark Evaluation Program (ICSBEP) were reviewed and modeled in MCNP. An average bias of less than 0.6% was determined using the ENDF/B-VII cross-section libraries except in the case of subcritical experiments, which exhibited an average bias of approximately 1.5%. The bias increases with increasing reflector worth of the beryllium. The uncertainties and sensitivities in cross section data for the FSP model and ZPPR-20 configurations were assessed using TSUNAMI-3D. The cross-section covariance uncertainty in the FSP model was calculated as 2.09%, which was dominated by the uncertainty in the 235U(n,?) reactions. Global integral indices were generated in TSUNAMI-IP using pre-release SCALE 6 cross-section covariance data. The ZPPR-20 benchmark models exhibit strong similarity with the FSP model. A penalty assessment was performed to determine the degree of which the FSP model could not be characterized

  13. Los Alamos opacity web page

    SciTech Connect

    Magee, N.H. Jr.; Clark, R.E.H.

    1998-02-01

    The Los Alamos opacity data base is now available on the World Wide Web at http://t4.lanl.gov. The data base contains both the original Astrophysical Opacity Library distributed worldwide in the 1980`s (for historical reference) and the new improved opacities from the Light Element Detailed Configuration OPacity (LEDCOP) code. Users can access the opacity data using the multigroup opacity code TOPS to obtain Rosseland and Planck gray opacities, group mean opacities over selected energy ranges, the monochromatic absorption coefficients and the average ionization over a wide range of temperatures and densities. As described in this paper, these quantities are available for all of the elements presently on the data base and TOPS will provide the same quantities for any arbitrary mixture of these elements.

  14. Los Alamos PC estimating system

    SciTech Connect

    Stutz, R.A.; Lemon, G.D.

    1987-01-01

    The Los Alamos Cost Estimating System (QUEST) is being converted to run on IBM personal computers. This very extensive estimating system is capable of supporting cost estimators from many different and varied fields. QUEST does not dictate any fixed method for estimating. QUEST supports many styles and levels of detail estimating. QUEST can be used with or without data bases. This system allows the estimator to provide reports based on levels of detail defined by combining work breakdown structures. QUEST provides a set of tools for doing any type of estimate without forcing the estimator to use any given method. The level of detail in the estimate can be mixed based on the amount of information known about different parts of the project. The system can support many different data bases simultaneously. Estimators can modify any cost in any data base.

  15. Use of Sensitivity and Uncertainty Analysis in the Design of Reactor Physics and Criticality Benchmark Experiments for Advanced Nuclear Fuel

    SciTech Connect

    Rearden, B.T.; Anderson, W.J.; Harms, G.A.

    2005-08-15

    Framatome ANP, Sandia National Laboratories (SNL), Oak Ridge National Laboratory (ORNL), and the University of Florida are cooperating on the U.S. Department of Energy Nuclear Energy Research Initiative (NERI) project 2001-0124 to design, assemble, execute, analyze, and document a series of critical experiments to validate reactor physics and criticality safety codes for the analysis of commercial power reactor fuels consisting of UO{sub 2} with {sup 235}U enrichments {>=}5 wt%. The experiments will be conducted at the SNL Pulsed Reactor Facility.Framatome ANP and SNL produced two series of conceptual experiment designs based on typical parameters, such as fuel-to-moderator ratios, that meet the programmatic requirements of this project within the given restraints on available materials and facilities. ORNL used the Tools for Sensitivity and Uncertainty Analysis Methodology Implementation (TSUNAMI) to assess, from a detailed physics-based perspective, the similarity of the experiment designs to the commercial systems they are intended to validate. Based on the results of the TSUNAMI analysis, one series of experiments was found to be preferable to the other and will provide significant new data for the validation of reactor physics and criticality safety codes.

  16. Criticality experiments and analysis of molybdenum reflected cylindrical uranyl fluoride water solution reactors

    NASA Technical Reports Server (NTRS)

    Fieno, D.; Fox, T.; Mueller, R.

    1972-01-01

    Clean criticality data were obtained from molybdenum-reflected cylindrical uranyl-fluoride-water solution reactors. Using ENDF/B molybdenum cross sections, a nine energy group two-dimensional transport calculation of a reflected reactor configuration predicted criticality to within 7 cents of the experimental value. For these reactors, it was necessary to compute the reflector resonance integral by a detailed transport calculation at the core-reflector interface volume in the energy region of the two dominant resonances of natural molybdenum.

  17. Care, compassion and competence in critical care: a qualitative exploration of nurses' experience of family witnessed resuscitation.

    PubMed

    Monks, Justine; Flynn, Maria

    2014-12-01

    This exploratory study was grounded in a local initiative promoting family witnessed resuscitation in the critical care units of a regional cardio-thoracic centre in the United Kingdom (UK). Research in this field has focussed on the perceived benefits, or otherwise, of family involvement, but little is known about the impact this has on critical care nurses or their practice. This study aimed to gain insights into nurses' experience of family witnessed resuscitation and identify any implications for critical care practices. The study employed a phenomenological approach and interviewed six nurses who had been involved in family witnessed resuscitation. Data from the transcribed interviews were analysed thematically and organised into descriptive categories which reflected the nursing experience of these resuscitation events. The three thematic categories generated by data analysis illustrate the challenges nurses faced in seeking to balance compassionate care and technical competence in emergency situations on critical care units. They also showed how nurses sought to reconcile unsettling emotions with their professional practice and responsibilities. The findings of this study are consistent with what is already known about the challenges of critical care nursing, but suggest that more research is needed to understand the practical and emotional complexities of family witnessed resuscitation.

  18. DOES CRITICAL MASS DECREASE AS TEMPERATURE INCREASES: A REVIEW OF FIVE BENCHMARK EXPERIMENTS THAT SPAN A RANGE OF ELEVATED TEMPERATURES AND CRITICAL CONFIGURATIONS

    SciTech Connect

    Yates, K.

    2009-06-10

    Five sets of benchmark experiments are reviewed herein that cover a diverse set of fissile system configurations. The review specifically focused on the change in critical mass of these systems at elevated temperatures and the temperature reactivity coefficient ({alpha}{sub T}) on the system. Because plutonium-based critical benchmark experiments at varying temperatures were not found at the time this review was prepared, only uranium-based systems are included, as follows: (1) HEU-SOL-THERM-010 - UO{sub 2}F{sub 2} solutions with high U{sup 235} enrichment; (2) HEU-COMP-THERM-016 - uranium-graphite blocks with low U concentration; (3) LEU-COMP-THERM-032 - water moderated lattices of UO{sub 2} with stainless steel cladding, and intermediate U{sup 235} enrichment; (4) IEU-COMP-THERM-002 - water moderated lattices of annular UO{sub 2} with/without absorbers, and intermediate U{sup 235} enrichment; and (5) LEU-COMP-THERM-026 - water moderated lattices of UO{sub 2} at different pitches, and low U{sup 235} enrichment. In three of the five benchmarks (1, 3 and 5), modeling of the critical system at room temperature is conservative compared to modeling the system at elevated temperatures, i.e., a greater fissile mass is required at elevated temperature. In one benchmark (4), there was no difference in the fissile mass between the room temperature system and the system at the examined elevated temperature. In benchmark (2), the system clearly had a negative temperature reactivity coefficient. Some of the high temperature benchmark experiments were treated with appropriate (and comprehensive) adjustments to the cross section sets and thermal expansion coefficients, while other experiments were treated with partial adjustments. Regardless of the temperature treatment, modeling the systems at room temperature was found to be conservative for the examined systems, i.e., a smaller critical mass was obtained. While the five benchmarks presented herein demonstrate that, for the

  19. Tiger Team Assessment of the Los Alamos National Laboratory

    SciTech Connect

    Not Available

    1991-11-01

    The purpose of the safety and health assessment was to determine the effectiveness of representative safety and health programs at the Los Alamos National Laboratory (LANL). Within the safety and health programs at LANL, performance was assessed in the following technical areas: Organization and Administration, Quality Verification, Operations, Maintenance, Training and Certification, Auxiliary Systems, Emergency Preparedness, Technical Support, Packaging and Transportation, Nuclear Criticality Safety, Security/Safety Interface, Experimental Activities, Site/Facility Safety Review, Radiological Protection, Personnel Protection, Worker Safety and Health (OSHA) Compliance, Fire Protection, Aviation Safety, Explosives Safety, Natural Phenomena, and Medical Services.

  20. ACCELERATION OF LOS ALAMOS NATIONAL LABORATORY TRANSURANIC WASTE DISPOSITION

    SciTech Connect

    O'LEARY, GERALD A.

    2007-01-04

    Energy Los Alamos Site Office, Carlsbad Field Office and the Department of Energy Headquaeters. Rather than simply processing containers as retrieved, the plan places priority on efficient curie disposition, a direct correlation to reducing risk. Key elements of the approch include balancing inventory and operational risks, tailoring methods to meet requirements, optimizing existing facilities, equipment and staff, and incorporating best practices from other Department of Energy sites. With sufficient funding this will enable LANL to ship the above-ground high activity contact-handled transuranic waste offsite by the end of Fiscal Year (FY) 2007 and to disposition the remaining above- and below-ground contact-handled and remote-handled transuranic waste inventory by December 2010. Nearly 70% of the contact-handled transuranic waste containers, including the high activity waste, require processing and repackaging before characterization and certification for shipment to the Waste Isolation Pilot Plant. LANL is employing a balanced risk approach that accomplishes significant long-term risk reduction by accepting short-term increased facility operations risk under well-developed and justified interim controls. Reviews of facility conditions and additional analyses show that the Waste Characterization, Reduction and Repackaging Facility and the Radioassay and Nondestructive Testing Facility are the most appropriate facilities to safetly remediate, repackage, and ship lower activity and the remaining high activity drums. Updated safety documentation supporting limited Hazard Category 2 operations in these facilities has been developed. Once approved, limited-term operations to process the high activity drums can begin in early 2007, building upon the experience base established performing Hazard Category 3 operations processing lower activity waste in these facilities. LANL is also implementing a series of actions to improve and sustain operations for processing contact

  1. Absence of critical exponents in ferroelectrics: experiments of Hilczer and theory of Levanyuk and Sigov

    NASA Astrophysics Data System (ADS)

    Scott, J. F.

    2016-08-01

    The pioneering breakthrough of Bozena Hilczer and her coworkers showed that the so-called critical phenomena in many ferroelectric crystals are entirely produced by defects. She studied gadolinium aluminum sulphate hexahydrate (GASH), lithium ammonium sulphate, lithium hydrazinium sulphate, PZT, barium titanate, and especially TGS, via neutron irradiation, X-ray irradiation, and e-beam electron irradiation, which showed that the divergences in specific heat or dielectric constant near the Curie temperature Tc are not caused by 'critical' fluctuations but by static defects, which can be annealed out and subsequently reproduced by irradiation. This work is rarely cited (modern physicists often feel that literature searches are optional), leading to frequent rediscovery and generally spurious claims of true 'critical' phenomena near Tc.

  2. Critical heat-flux experiments under low-flow conditions in a vertical annulus. [PWR; BWR; LMFBR

    SciTech Connect

    Mishima, K.; Ishii, M.

    1982-03-01

    An experimental study was performed on critical heat flux (CHF) at low flow conditions for low pressure steam-water upward flow in an annulus. The test section was transparent, therefore, visual observations of dryout as well as various instrumentations were made. The data indicated that a premature CHF occurred due to flow regime transition from churn-turbulent to annular flow. It is shown that the critical heat flux observed in the experiment is essentially similar to a flooding-limited burnout and the critical heat flux can be well reproduced by a nondimensional correlation derived from the previously obtained criterion for flow regime transition. The observed CHF values are much smaller than the standard high quality CHF criteria at low flow, corresponding to the annular flow film dryout. This result is very significant, because the coolability of a heater surface at low flow rates can be drastically reduced by the occurrence of this mode of CHF.

  3. Sunset at the ALaMO

    NASA Video Gallery

    A new color all-sky camera has opened its eyes at the ALaMO, or Automated Lunar and Meteor Observatory, at NASA's Marshall Space Flight Center in Huntsville, Ala. Watch its inaugural video below, s...

  4. Publications of Los Alamos research 1988

    SciTech Connect

    Varjabedian, K.; Dussart, S.A.; McClary, W.J.; Rich, J.A.

    1989-12-01

    This bibliography lists unclassified publications of work done at the Los Alamos National Laboratory for 1988. The entries, which are subdivided by broad subject categories, are cross-referenced with an author index and a numeric index.

  5. New Rad Lab for Los Alamos

    SciTech Connect

    2008-08-06

    The topping out ceremony for a key construction stage in the Los Alamos National Laboratory's newest facility, the Radiological Laboratory Utility & Office Building. This is part of the National Nu...  

  6. Environmental surveillance at Los Alamos during 1994

    SciTech Connect

    1996-07-01

    This report describes environmental monitoring activities at Los Alamos National Laboratory for 1994. Data were collected to assess external penetrating radiation, airborne emissions, liquid effluents, radioactivity of environmental materials and food stuffs, and environmental compliance.

  7. New Rad Lab for Los Alamos

    ScienceCinema

    None

    2016-07-12

    The topping out ceremony for a key construction stage in the Los Alamos National Laboratory's newest facility, the Radiological Laboratory Utility & Office Building. This is part of the National Nu...  

  8. What Matters in College to Students: Critical Incidents in the Undergraduate Experience

    ERIC Educational Resources Information Center

    Vianden, Jörg

    2015-01-01

    This article advances that undergraduates are partners to higher education institutions in establishing the educational enterprise. Leaning on student relationship management as a theoretical construct and the critical incident technique as method, the study found 58 undergraduates' interpersonal interactions with faculty, staff, and peers…

  9. New Graduate Nurses' Perceived Definition of Critical Thinking during Their First Nursing Experience

    ERIC Educational Resources Information Center

    Kaddoura, Mahmoud

    2013-01-01

    Critical thinking (CT) is a flourishing concept that has been developing throughout the fields of both nursing education and practice. In fact, every person thinks in his or her own way that is varied among individuals; it is the nature of human mankind to do so. Nevertheless, much of our thinking might be subjective, indefinite, limited,…

  10. Into the Unknown: A Critical Reflection on a Truly Global Learning Experience

    ERIC Educational Resources Information Center

    Wolf, Katharina; Archer, Catherine

    2013-01-01

    Over the past decade, industry relevance and connectedness have evolved into a key requirement for students and their parents, who increasingly perceive employability upon graduation as a critical factor in the degree selection process. Simultaneously, professional bodies emphasise the need for high levels of industry engagement as a condition for…

  11. Voice, Identity, and the Organizing of Student Experience: Managing Pedagogical Dilemmas in Critical Classroom Discussions

    ERIC Educational Resources Information Center

    Yannuzzi, Thomas J.; Martin, Daniela

    2014-01-01

    The current paper explores the discursive complexities of teaching and learning in inclusive, critically oriented classrooms. It argues that to accomplish the ontological goals of higher learning, we need to focus on the construction of student voice, or the ability to be considered in and have influence on teaching and learning. The paper further…

  12. Challenging "Size Matters" Messages: An Exploration of the Experiences of Critical Obesity Scholars in Higher Education

    ERIC Educational Resources Information Center

    Cameron, Erin

    2016-01-01

    Given that postsecondary institutions are increasingly seen as sites to promote health, critical scholars are calling attention to how the contemporary Western weight-centred health paradigm reinforces a "size matters" message that is fueling harmful attitudes towards and judgments of bodies. As such, research that highlights strategies…

  13. Critically Ill Patients and End-of-Life Decision-Making: The Senior Medical Resident Experience

    ERIC Educational Resources Information Center

    Ahern, Stephane P.; Doyle, Tina K.; Marquis, Francois; Lesk, Corey; Skrobik, Yoanna

    2012-01-01

    In order to improve the understanding of educational needs among residents caring for the critically ill, narrative accounts of 19 senior physician trainees participating in level of care decision-making were analyzed. In this multicentre qualitative study involving 9 university centers in Canada, in-depth interviews were conducted in either…

  14. Critical Reflection by Teacher Candidates on Cases Based in their Experience: Teacher Education for Inclusive Education

    ERIC Educational Resources Information Center

    Hutchinson, Nancy L.

    2004-01-01

    Recent changes in education, including inclusion of students with disabilities, promise to heighten the complexity of teaching. Preparing reflective teachers may help to deal with these increasing demands. This paper reports analysis of critical reflection and two other features in cases authored by teacher candidates and submitted in a course on…

  15. The Steward Street School Experiment: A Critical Case Study of Possibilities

    ERIC Educational Resources Information Center

    Burke, Catherine; Grosvenor, Ian

    2013-01-01

    This article presents a critical case study of an inner city state school that for a decade (1940s-1950s) attracted the interest of a wide contingency of educationalists, policy makers, researchers, artists and various press and film media. It has been argued that if we are to progress "social alternatives" in education, researchers need to…

  16. Reconceptualizing Self and Other through Critical Media Engagement. Experiences and Reflections of English Learners and Teacher

    ERIC Educational Resources Information Center

    Huang, Shin-ying

    2015-01-01

    This research explores how critical media literacy transforms ways of engaging with media texts and expands the understanding and practice of literacy. In this qualitative teacher inquiry, even though the teacher researcher had envisioned for the students an identity as academic-language learners who engage with competing ideologies of masculinity…

  17. A Critical Ethnography of the Hmong Experience in the Upward Bound Program

    ERIC Educational Resources Information Center

    Daniels, Quincey L.

    2012-01-01

    The purpose of this study was to determine the perceptions of Hmong students regarding the Upward Bound Program and how those perceptions related to their participation in the program. A critical ethnography of Hmong students in the Upward Bound Program was conducted and included an examination of potential inequities by creating a literal…

  18. Women's experiences of symptoms of posttraumatic stress disorder (PTSD) after traumatic childbirth: a review and critical appraisal.

    PubMed

    James, Stella

    2015-12-01

    This paper critically analyses nine studies on postnatal posttraumatic stress disorder (PTSD) following traumatic childbirth, in order to find common themes of PTSD symptoms, using the cognitive model of PTSD as a guide; it critically appraised one of the studies in depth and it attempted to explain the lived experience of women suffering from postnatal PTSD following traumatic childbirth and the suitability of cognitive behavioural therapy (CBT) for postnatal PTSD. This paper found that women following traumatic childbirth do experience postnatal PTSD; postnatal PTSD symptoms are similar to PTSD symptoms of other events and that CBT for PTSD of other events is just as effective for postnatal PTSD. Future recommendations include more qualitative studies with interpretative phenomenological approach in order to establish evidence-based CBT treatment for this client group, and more referrals need to be sent to the psychological services for CBT intervention.

  19. Edward Teller Returns to LOS Alamos

    NASA Astrophysics Data System (ADS)

    Hecker, Siegfried S.

    2010-01-01

    I was asked to share some reflections of Edward Teller's return to Los Alamos during my directorship. I met Teller late in his life. My comments focus on that time and they will be mostly in the form of stories of my interactions and those of my colleagues with Teller. Although the focus of this symposium is on Teller's contributions to science, at Los Alamos it was never possible to separate Teller's science from policy and controversy ...

  20. Internship at Los Alamos National Laboratory

    SciTech Connect

    Dunham, Ryan Q.

    2012-07-11

    Los Alamos National Laboratory (LANL) is located in Los Alamos, New Mexico. It provides support for our country's nuclear weapon stockpile as well as many other scientific research projects. I am an Undergraduate Student Intern in the Systems Design and Analysis group within the Nuclear Nonproliferation division of the Global Security directorate at LANL. I have been tasked with data analysis and modeling of particles in a fluidized bed system for the capture of carbon dioxide from power plant flue gas.

  1. Criticality analysis of selected Saxton Plutonium Program experiments using WIMS-D4M and DIF3D

    SciTech Connect

    Cuevas Vivas, G.F.; Parish, T.A.

    1998-08-01

    The Saxton critical experiments were simulated with homogenized region, multigroup cross sections from the WIMS-D4M lattice physics code (ENDF/B-V library) and the diffusion code, DIF3D. The simulations were focused on assessing the codes` capabilities, including the different cell models available in WIMS-D4M. The accuracy of the core power distributions obtained with DIF3D has also been assessed. The number of experiments and their variety was used to obtain statistical parameters that allow a quantitative discussion of the assessment of the methodology.

  2. Los Alamos Space Weather Summer School

    NASA Astrophysics Data System (ADS)

    Koller, J.

    2011-12-01

    Los Alamos National Lab recently initiated a new summer school specializing on space science, space weather, and instrumentation. The school is geared towards graduate level students and has been established to bring graduate students together with internationally recognized scientists at the Los Alamos National Lab. Students are receiving a prestigious Vela Fellowship to cover relocation expenses and cost of living for the duration of their stay in Los Alamos. For two months students have the opportunity to attend science lectures given by distinguished researchers at LANL. Topics are related to space weather research including plasma physics, radiation belts, numerical modeling, solar wind physics, spacecraft charging, and instrumentation. Students are also working closely with a Los Alamos mentor on exciting space weather science topics with access to Los Alamos GPS and geosynchronous data. The summer school concludes with project presentations by the students in a technical forum. The program is designed for graduate students currently enrolled at US Universities and open to all nationalities. We are presenting an overview of this exciting new program funded by IGPP (Institute of Geophysics and Planetary Physics), the Global Security Directorate, and the Directorate for Science, Technology and Engineering at Los Alamos National Lab.

  3. Critical Factors in On-Campus Clinical Experiences: Perceptions of Preservice Teachers.

    ERIC Educational Resources Information Center

    Metcalf, Kim K.

    1993-01-01

    Indiana University's Teacher Education Laboratory replaces and supplements portions of the preservice program previously provided through field placements in area schools. This article describes the initial field test of a laboratory experience for secondary education majors. Surveys rating students' attitudes about the experience indicated…

  4. HBCUs as Critical Context for Identity Work: Reflections, Experiences, and Lessons Learned

    ERIC Educational Resources Information Center

    Greenfield, Derek F.; Innouvong, Tony; Aglugub, Richard Jay; Yusuf, Ismail A.

    2015-01-01

    Using narratives from a diverse group of students and staff in terms of race and religion, this chapter gives voice to these individuals' experiences with issues of diversity and inclusion at an HBCU. This chapter also discusses how these experiences helped to facilitate the authors' racial and cultural identity development.

  5. Effects of Diversity Experiences on Critical Thinking Skills over 4 Years of College

    ERIC Educational Resources Information Center

    Pascarella, Ernest T.; Martin, Georgianna L.; Hanson, Jana M.; Trolian, Teniell L.; Gillig, Benjamin; Blaich, Charles

    2014-01-01

    The benefits of student engagement in diversity experiences on a range of college outcomes have been well documented. However, the potential influence of involvement in diversity experiences during college on the cognitive and intellectual outcomes of post-secondary education is only beginning to be understood. Gurin et al. (2002) made a…

  6. Los Alamos Laser Eye Investigation.

    SciTech Connect

    Odom, C. R.

    2005-01-01

    A student working in a laser laboratory at Los Alamos National Laboratory sustained a serious retinal injury to her left eye when she attempted to view suspended particles in a partially evacuated target chamber. The principle investigator was using the white light from the flash lamp of a Class 4 Nd:YAG laser to illuminate the particles. Since the Q-switch was thought to be disabled at the time of the accident, the principal investigator assumed it would be safe to view the particles without wearing laser eye protection. The Laboratory Director appointed a team to investigate the accident and to report back to him the events and conditions leading up to the accident, equipment malfunctions, safety management causal factors, supervisory and management action/inaction, adequacy of institutional processes and procedures, emergency and notification response, effectiveness of corrective actions and lessons learned from previous similar events, and recommendations for human and institutional safety improvements. The team interviewed personnel, reviewed documents, and characterized systems and conditions in the laser laboratory during an intense six week investigation. The team determined that the direct and primary failures leading to this accident were, respectively, the principle investigator's unsafe work practices and the institution's inadequate monitoring of worker performance. This paper describes the details of the investigation, the human and institutional failures, and the recommendations for improving the laser safety program.

  7. Analysis of Np-237 ENDF for the theortical interpretation of critical assembly experiments.

    SciTech Connect

    Mihaila, B.; Chadwick, M. B.; MacFarlane, R. E.; Kawano, T.

    2004-01-01

    We report on the present status of our effort toward an improved Np-237 evaluated nuclear data file (ENDF). The aim here is to bridge the gap between calculated and observed k-eff values, as measured at the Np-U critical assembly at LANL, TA-18. As such, we perform a critical analysis of the existing body of experimental data and recommended evaluations. We are targeting in principal the fission nu-bar and cross section in Np-237, as well as the inelastic scattering which is particularly important since Np-237 is a threshold fissioner. This analysis will be employed in a future sensitivity study of the calculated k-eff with respect to variations of the afore mentioned nuclear data.

  8. Temperature Gradients on the Cell Wall in the Critical Viscosity Experiment

    NASA Technical Reports Server (NTRS)

    Berg, Robert F.; Moldover, Michael R.

    1993-01-01

    Because of the diverging susceptibility delta rho/delta Tau near the liquid-vapor critical point, temperature gradients must be kept small to maintain adequate sample homogeneity. In our Science Requirements Document we paid particular attention to radial density gradients caused by equilibration of the xenon sample. Axial density gradients were addressed through the requirement that the cell's copper wall have a gradient less than 22 microK/m. This report re-examines the cell wall's temperature distribution in more detail by estimating all known significant contributions to temperature differences on the cell's wall.

  9. ISS-Crystal Growth of Photorefractive Materials (BSO): Critical Design Issues for Optimized Data Extraction from Space Experiments

    NASA Technical Reports Server (NTRS)

    Hyers, Robert W.; Motakef, S.; Witt, A. F.; Wuensch, B.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Realization of the full potential of photorefractive materials in device technology is seriously impeded by our inability to achieve controlled formation of critical defects during single crystal growth and by difficulties in meeting the required degree of compositional uniformity on a micro-scale over macroscopic dimensions. The exact nature and origin of the critical defects which control photorefractivity could not as yet be identified because of gravitational interference. There exists, however, strong evidence that the density of defect formation and their spatial distribution are adversely affected by gravitational interference which precludes the establishment of quantifiable and controllable heat and mass transfer conditions during crystal growth. The current, NASA sponsored research at MIT is directed at establishing a basis for the development of a comprehensive approach to the optimization of property control during melt growth of photorefractive materials, making use of the m-g environment, provided in the International Space Station. The objectives to be pursued in m-g research on photorefractive BSO (Bi12SiO20) are: (a) identification of the x-level(s) responsible for photorefractivity in undoped BSO; (b) development of approaches leading to the control of x-level formation at uniform spatial distribution; (c) development of doping and processing procedures for optimization of the critical, application specific parameters, spectral response, sensitivity, response time and matrix stability. The presentation will focus on: the rationale for the justification of the space experiment, ground-based development efforts, design considerations for the space experiments, strategic plan of the space experiments, and approaches to the quantitative analysis of the space experiments.

  10. A critical period for experience-dependent remodeling of adult-born neuron connectivity.

    PubMed

    Bergami, Matteo; Masserdotti, Giacomo; Temprana, Silvio G; Motori, Elisa; Eriksson, Therese M; Göbel, Jana; Yang, Sung Min; Conzelmann, Karl-Klaus; Schinder, Alejandro F; Götz, Magdalena; Berninger, Benedikt

    2015-02-18

    Neurogenesis in the dentate gyrus (DG) of the adult hippocampus is a process regulated by experience. To understand whether experience also modifies the connectivity of new neurons, we systematically investigated changes in their innervation following environmental enrichment (EE). We found that EE exposure between 2-6 weeks following neuron birth, rather than merely increasing the number of new neurons, profoundly affected their pattern of monosynaptic inputs. Both local innervation by interneurons and to even greater degree long-distance innervation by cortical neurons were markedly enhanced. Furthermore, following EE, new neurons received inputs from CA3 and CA1 inhibitory neurons that were rarely observed under control conditions. While EE-induced changes in inhibitory innervation were largely transient, cortical innervation remained increased after returning animals to control conditions. Our findings demonstrate an unprecedented experience-dependent reorganization of connections impinging onto adult-born neurons, which is likely to have important impact on their contribution to hippocampal information processing.

  11. Experience of critical incident stress among ambulance service staff and relationship to psychological symptoms.

    PubMed

    Gallagher, Sharon; McGilloway, Sinéad

    2009-01-01

    This two-stage study was undertaken to assess the extent and nature of Critical Incident Stress (CIS) amongst frontline staff in a large ambulance service in Ireland. In Stage One, 63% (112/180) of participants completed a Screening Questionnaire and the GHQ-12. In Stage Two, 27 participants, who had experienced a critical incident (CI) during the previous year completed several measures to assess PTSD symptomatology, burnout, health-related Quality of Life, and dispositional optimism. Eighty-one per cent (80/94) of the Stage One group reported that their health had been affected by a CI; 42% (44/106) were identified as 'cases' on the GHQ-12. Stage Two results indicated that 12 participants had PTSD symptoms while this entire group showed moderate levels of emotional exhaustion and depersonalization, despite experiencing high levels of personal accomplishment and optimism. The findings suggest a high prevalence of CIS among ambulance personnel in Ireland and a significant impact on overall health and wellbeing. This has important implications for the effective management of CIS and suggests an important role for occupational health and organizational psychologists in providing routine support to ambulance service staff andpossibly other emergency services personnel.

  12. Accelerators for critical experiments involving single-particle upset in solid-state microcircuits

    NASA Technical Reports Server (NTRS)

    Zoutendyk, J. A.

    1985-01-01

    Charged-particle interactions in microelectronic circuit chips (integrated circuits) present a particularly insidious problem for solid-state electronic systems due to the generation of soft errors or single-particle event upset (SEU) by either cosmic rays or other radiation sources. Particle accelerators are used to provide both light and heavy ions in order to assess the propensity of integrated circuit chips for SEU. Critical aspects of this assessment involve the ability to analytically model SEU for the prediction of error rates in known radiation environments. In order to accurately model SEU, the measurement and prediction of energy deposition in the form of an electron-hole plasma generated along an ion track is of paramount importance. This requires the use of accelerators which allow for ease in both energy control (change of energy) and change of ion species. This and other aspects of ion-beam control and diagnostics (e.g., uniformity and flux) are of critical concern for the experimental verification of theoretical SEU models.

  13. Validation of HELIOS Neutron Cross-Section Library for RBMK Reactors Against the Data From the Critical Facility Experiments

    SciTech Connect

    Jasiulevicius, Audrius; Sehgal, Bal Raj

    2002-07-01

    The RBMK reactors are channel type, water-cooled and graphite moderated reactors. The first RBMK type electricity production reactor was put on-line in 1973. Currently there are 13 operating reactors of this type. Two of the RBMK-1500 reactors are at the Ignalina NPP in Lithuania. Experimental Critical Facility for RBMK reactors, located at Kurchatov Institute, Moscow was designed to carry out critical reactivity experiments on assemblies, which imitate parts of the RBMK reactor core. The facility is composed of Control and Protection Rods (CPR's), fuel assemblies with different enrichment in U-235 and other elements, typical for RBMK reactor core loadings, e.g. additional absorber assemblies, CPR imitators, etc. A simulation of a set of the experiments, performed at the Experimental Critical Facility, was carried out at the Royal Institute of Technology (RIT), Nuclear Power Safety Division, using CORETRAN 3-D neutron dynamics code. The neutron cross sections for assemblies were calculated using HELIOS code. The aim of this work was to evaluate capabilities of the HELIOS code to provide correct cross section data for the RBMK reactor. The calculation results were compared to the similar CORETRAN calculations, when employing WIMS-D4 code generated cross section data. For some of the experiments, where calculation results with CASMO-4 code generated cross sections are available, the comparison is also performed against CASMO-4 results. Eleven different experiments were simulated. Experiments differ in size of the facility core (number of assemblies loaded): from simple core loadings, composed only of a few fuel assemblies, to complicated configurations, which represent a part of the RBMK reactor core. Diverse types of measurements were carried out during these experiments: reactivity, neutron flux distributions (both axial and radial), rod reactivity worth and the voiding effects. Results of the reactivity measurements and relative neutron flux distributions were

  14. Critical Race Reflections: Valuing the Experiences of Teachers of Color in Teacher Education

    ERIC Educational Resources Information Center

    Kohli, Rita

    2009-01-01

    While research has demonstrated that White teachers often must be taught about the pain of racism in order to not perpetuate it, this may not apply to racial minority teachers. Through personal experience, Teachers of Color are likely aware of the trauma that racism can cause students. Within teacher education, we must create research and teaching…

  15. Community College Students' Experiences with Financial Aid Policies and Practices: A Critical Case Study

    ERIC Educational Resources Information Center

    White, Julie A.

    2013-01-01

    This case study describes community college students' experiences with governmental financial aid policies and institutional financial aid processes at an urban community college campus in the Northeastern United States. Drawing from theories of social justice, conceptions of social capital, and institutionalist analyses of the community…

  16. Are Sojourners Natural Comparativists? Critical Perspectives on the Learning Experiences of International Students

    ERIC Educational Resources Information Center

    Schweisfurth, Michele

    2012-01-01

    Students who spend a period of time studying outside of their own national systems have a number of advantages in terms of developing a comparative perspective on education. The experience of living and studying abroad provides them with the opportunity to act as participant observers of at least two different systems, and the natural…

  17. Is This a Meaningful Learning Experience? Interactive Critical Self-Inquiry as Investigation

    ERIC Educational Resources Information Center

    Allard, Andrea C.; Gallant, Andrea

    2012-01-01

    What conditions enable educators to engage in meaningful learning experiences with peers and beginning practitioners? This article documents a self-study on our actions-in-practice in a peer mentoring project. The investigation involved an iterative process to improve our knowledge as teacher educators, reflective practitioners, and researchers.…

  18. Enhancing Critical Consciousness through a Cross-Cultural Immersion Experience in South Africa

    ERIC Educational Resources Information Center

    Choi, Kyoung Mi; VanVoorhis, Richard W.; Ellenwood, Audrey E.

    2015-01-01

    Using phenomenological approaches, the author explored the meanings and essences of a cross-cultural immersion experience in South Africa among counseling master's-level students. Five core themes--the meaning of being American, sociopolitical awareness, engagement with South Africans and their communities, appreciation of life, and commitment to…

  19. Cumulative experiences with life adversity: Identifying critical levels for targeting prevention efforts

    PubMed Central

    Mitchell, Kimberly J.; Tynes, Brendesha; Umaña-Taylor, Adriana J.; Williams, David

    2015-01-01

    This paper aims to assess the role of individual types and cumulative life adversity for understanding depressive symptomatology and aggressive behavior. Data were collected in 2011 as part of the Teen Life Online and in Schools Study from 916 ethnically-diverse students from 12 middle, K-8, 6-12 and high schools in the Midwest United States. Youth reported an average of 4.1 non-victimization adversities and chronic stressors in their lifetimes. There was a linear relationship between number of adversities and depression and aggression scores. Youth reporting the highest number of adversities (7 or more) had significantly higher depression and aggression scores than youth reporting any other number of adversities suggesting exposure at this level is a critical tipping point for mental health concerns. Findings underscore an urgent need to support youth as they attempt to negotiate, manage, and cope with adversity in their social worlds. PMID:26057876

  20. Cumulative experiences with life adversity: Identifying critical levels for targeting prevention efforts.

    PubMed

    Mitchell, Kimberly J; Tynes, Brendesha; Umaña-Taylor, Adriana J; Williams, David

    2015-08-01

    This paper aims to assess the role of individual types and cumulative life adversity for understanding depressive symptomatology and aggressive behavior. Data were collected in 2011 as part of the Teen Life Online and in Schools Study from 916 ethnically-diverse students from 12 middle, K-8, 6-12 and high schools in the Midwest United States. Youth reported an average of 4.1 non-victimization adversities and chronic stressors in their lifetimes. There was a linear relationship between number of adversities and depression and aggression scores. Youth reporting the highest number of adversities (7 or more) had significantly higher depression and aggression scores than youth reporting any other number of adversities suggesting exposure at this level is a critical tipping point for mental health concerns. Findings underscore an urgent need to support youth as they attempt to negotiate, manage, and cope with adversity in their social worlds.

  1. Experiences with Extra-Vehicular Activities in Response to Critical ISS Contingencies

    NASA Technical Reports Server (NTRS)

    Van Cise, Edward A.; Kelly, Brian J.; Radigan, Jeffery P.; Cranmer, Curtis W.

    2016-01-01

    Initial "Big 14" work was put to the test for the first time in 2010. Deficiencies were found in some of the planning and approaches to that work; Failure Response Assessment Team created in 2010 to address deficiencies -Identify and perform engineering analysis in operations products prior to failure; incorporate results into operations products -Identify actions for protecting ISS against a Next Worse Failure after the first failure occurs -Better document not only EVA products but also planning products, assumptions, and open actions; Pre-failure investments against critical failures best postures ISS for swift response and recovery -A type of insurance policy -Has proven effective in a number of contingency EVA cases since 2010. Planning for MBSU R&R in 2012, Second PM R&R in 2013, EXT MDM R&R in 2014; Current FRAT schedule projects completion of all analysis in 2018

  2. Flow-Boiling Critical Heat Flux Experiments Performed in Reduced Gravity

    NASA Technical Reports Server (NTRS)

    Hasan, Mohammad M.; Mudawar, Issam

    2005-01-01

    Poor understanding of flow boiling in microgravity has recently emerged as a key obstacle to the development of many types of power generation and advanced life support systems intended for space exploration. The critical heat flux (CHF) is perhaps the most important thermal design parameter for boiling systems involving both heatflux-controlled devices and intense heat removal. Exceeding the CHF limit can lead to permanent damage, including physical burnout of the heat-dissipating device. The importance of the CHF limit creates an urgent need to develop predictive design tools to ensure both the safe and reliable operation of a two-phase thermal management system under the reduced-gravity (like that on the Moon and Mars) and microgravity environments of space. At present, very limited information is available on flow-boiling heat transfer and the CHF under these conditions.

  3. Microstructure, critical current density and trapped field experiments in IG-processed Y-123

    NASA Astrophysics Data System (ADS)

    Muralidhar, M.; Ide, N.; Koblischka, M. R.; Diko, P.; Inoue, K.; Murakami, M.

    2016-05-01

    In this paper, we adapted the top-seeded infiltration growth ‘IG’ technique and produced several YBa2Cu3O y ‘Y-123’ samples with an addition of Y2BaCuO5 ‘Y-211’ secondary phase particles with varying sizes by the sintering process and the ball milling technique. For the first set of samples, Y-211 disks were sintered at temperatures ranging between 900 °C and 1100 °C and were used for the production of Y-123 material by the IG process. Magnetization measurements showed a sharp superconducting transition with an onset T c at around 92 K, irrespective of the sintering temperature. However, the trapped field and critical current density (J c) values were dependent on the sintering temperature and it was found that the best temperature is around 925 °C. Further, the trapped field distribution measurements at 77 K indicated that all samples are of single grain nature. The highest trapped field was recorded around 0.31 T at 77 K for the Y-123 sample with 20 mm in diameter and 5 mm thickness produced by Y-211 pre-from around 925 °C. On the other hand, a second set of samples Y-211 were controlled by ball milling technique combined with an optimized slow cooling process. As a result, the critical current density (J c) at 77 K and zero field was determined to be 225 kA cm-2. The improved performance of the Y-123 material can be understood in terms of homogeneous distribution of fine secondary phase particles which is demonstrated by AFM micrographs.

  4. From Memory Impairment to Posttraumatic Stress Disorder-Like Phenotypes: The Critical Role of an Unpredictable Second Traumatic Experience.

    PubMed

    Finsterwald, Charles; Steinmetz, Adam B; Travaglia, Alessio; Alberini, Cristina M

    2015-12-01

    Arousal and stress critically regulate memory formation and retention. Increasing levels of stress produce an inverted U-shaped effect on cognitive performance, including the retention of explicit memories, and experiencing a severe stress during a traumatic event may lead to posttraumatic stress disorder (PTSD). The molecular mechanisms underlying the impairing effect of a severe stress on memory and the key contribution of traumatic experiences toward the development of PTSD are still unknown. Here, using increasing footshock intensities in an inhibitory avoidance paradigm, we reproduced the inverted U-shaped curve of memory performance in rats. We then show that the inverted U profile of memory performance correlates with an inverted U profile of corticosterone level in the circulation and of brain-derived neurotrophic factor, phosphorylated tropomyosin-receptor kinase B, and methyl CpG binding protein in the dorsal hippocampus. Furthermore, training with the highest footshock intensity (traumatic experience) led to a significant elevation of hippocampal glucocorticoid receptors. Exposure to an unpredictable, but not to a predictable, highly stressful reminder shock after a first traumatic experience resulted in PTSD-like phenotypes, including increased memory of the trauma, high anxiety, threat generalization, and resistance to extinction. Systemic corticosterone injection immediately after the traumatic experience, but not 3 d later, was sufficient to produce PTSD-like phenotypes. We suggest that, although after a first traumatic experience a suppression of the corticosterone-dependent response protects against the development of an anxiety disorder, experiencing more than one trauma (multiple hits) is a critical contributor to the etiology of PTSD. PMID:26631471

  5. Critical transition for the edge shear layer formation: Comparison of model and experiment

    SciTech Connect

    Carreras, B. A.; Garcia, L.; Pedrosa, M. A.; Hidalgo, C.

    2006-12-15

    The experimental results for the emergence of the plasma edge shear flow layer in TJ-II [C. Alehaldre et al.Fusion Technol. 17, 131 (1990)] can be explained using a simple model for a second-order transition based on the sheared flow amplification by Reynolds stress and turbulence suppression by shearing. In the dynamics of the model, the resistive interchange instability is used. This model gives power dependence on density gradients before and after the transition, consistent with experiment.

  6. From Memory Impairment to Posttraumatic Stress Disorder-Like Phenotypes: The Critical Role of an Unpredictable Second Traumatic Experience

    PubMed Central

    Finsterwald, Charles; Steinmetz, Adam B.; Travaglia, Alessio

    2015-01-01

    Arousal and stress critically regulate memory formation and retention. Increasing levels of stress produce an inverted U-shaped effect on cognitive performance, including the retention of explicit memories, and experiencing a severe stress during a traumatic event may lead to posttraumatic stress disorder (PTSD). The molecular mechanisms underlying the impairing effect of a severe stress on memory and the key contribution of traumatic experiences toward the development of PTSD are still unknown. Here, using increasing footshock intensities in an inhibitory avoidance paradigm, we reproduced the inverted U-shaped curve of memory performance in rats. We then show that the inverted U profile of memory performance correlates with an inverted U profile of corticosterone level in the circulation and of brain-derived neurotrophic factor, phosphorylated tropomyosin-receptor kinase B, and methyl CpG binding protein in the dorsal hippocampus. Furthermore, training with the highest footshock intensity (traumatic experience) led to a significant elevation of hippocampal glucocorticoid receptors. Exposure to an unpredictable, but not to a predictable, highly stressful reminder shock after a first traumatic experience resulted in PTSD-like phenotypes, including increased memory of the trauma, high anxiety, threat generalization, and resistance to extinction. Systemic corticosterone injection immediately after the traumatic experience, but not 3 d later, was sufficient to produce PTSD-like phenotypes. We suggest that, although after a first traumatic experience a suppression of the corticosterone-dependent response protects against the development of an anxiety disorder, experiencing more than one trauma (multiple hits) is a critical contributor to the etiology of PTSD. SIGNIFICANCE STATEMENT Increasing levels of stress produce an inverted U-shaped effect on memory retention. Humans experiencing an acute trauma may develop posttraumatic stress disorder (PTSD), but the key

  7. Criticality safety training

    SciTech Connect

    Woodruff, S.K.

    1997-06-01

    Criticality safety training is an important element of the Plutonium Facility safety program at Los Alamos National Laboratory. Training consists of student self-study handbooks and hands-on performance-based training in a mock-up laboratory containing gloveboxes, trolley conveyor system, and self-monitoring instruments. A 10-minute video tape and lecture was presented to describe how training in this area is conducted.

  8. Status of Monte Carlo at Los Alamos

    SciTech Connect

    Thompson, W.L.; Cashwell, E.D.

    1980-01-01

    At Los Alamos the early work of Fermi, von Neumann, and Ulam has been developed and supplemented by many followers, notably Cashwell and Everett, and the main product today is the continuous-energy, general-purpose, generalized-geometry, time-dependent, coupled neutron-photon transport code called MCNP. The Los Alamos Monte Carlo research and development effort is concentrated in Group X-6. MCNP treats an arbitrary three-dimensional configuration of arbitrary materials in geometric cells bounded by first- and second-degree surfaces and some fourth-degree surfaces (elliptical tori). Monte Carlo has evolved into perhaps the main method for radiation transport calculations at Los Alamos. MCNP is used in every technical division at the Laboratory by over 130 users about 600 times a month accounting for nearly 200 hours of CDC-7600 time.

  9. New Generation of Los Alamos Opacity Tables

    NASA Astrophysics Data System (ADS)

    Colgan, James; Kilcrease, D. P.; Magee, N. H.; Sherrill, M. E.; Abdallah, J.; Hakel, P.; Fontes, C. J.; Guzik, J. A.; Mussack, K. A.

    2016-05-01

    We present a new generation of Los Alamos OPLIB opacity tables that have been computed using the ATOMIC code. Our tables have been calculated for all 30 elements from hydrogen through zinc and are publicly available through our website. In this poster we discuss the details of the calculations that underpin the new opacity tables. We also show several recent applications of the use of our opacity tables to solar modeling and other astrophysical applications. In particular, we demonstrate that use of the new opacities improves the agreement between solar models and helioseismology, but does not fully resolve the long-standing `solar abundance' problem. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396.

  10. Publications of Los Alamos Research, 1983

    SciTech Connect

    Sheridan, C.J.; McClary, W.J.; Rich, J.A.; Rodriguez, L.L.

    1984-10-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1983. Papers published in 1982 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers publishd in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

  11. Publications of Los Alamos research 1980

    SciTech Connect

    Salazar, C.A.; Willis, J.K.

    1981-09-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1980. Papers published in 1980 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted-even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was pubished more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-laboratory reports, journal articles, books, chapters of books, conference papers published either separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

  12. Solar pond research at the Los Alamos National Laboratory

    SciTech Connect

    Jones, G.F.; Meyer, K.A.; Hedstrom, J.C.; Grimmer, D.P.

    1984-01-01

    A description of solar pond research at Los Alamos National Laboratory is presented. The main issues in the theory of solar ponds are discussed. Among these are the interfacial-boundary-layer model, models for interface motion and pond performance, heat extraction, and ground heat loss. The core of the research effort at Los Alamos was the development of a one-dimensional computer program to accurately predict dynamic performance of a solar pond. The computer model and the experiments that were designed and performed to validate it are described. The experiments include two laboratory tanks wherein temperature, salinity, and flow visualization data were obtained and a 232 m/sup 2/ outdoor solar pond. Results from preliminary validation show good agreement between the pond's predicted dynamic behavior and that which actually occurred in the experiments. More validation using data from full-sized solar ponds is needed. A new correlation for the ratio of interfacial salt-flux to heat-flux is proposed which agrees well with our data. Recommendations for future research are given.

  13. Turbulent opposed-jet flames: A critical benchmark experiment for combustion LES

    SciTech Connect

    Geyer, D.; Dreizler, A.; Janicka, J.; Kempf, A.

    2005-12-01

    Turbulent opposed-jet configurations have gained attention as a challenging test case to validate the mixing and combustion models used in the simulation of turbulent combustion. In general, validation requires comprehensive experimental information on flow and scalar fields, and the emergence of combustion large-eddy simulation (CLES) necessitated more advanced diagnostics. These laser-optical techniques allow measurements not only of single-point statistics but of structural information of the flame, such as correlations, gradients, and structure functions. This paper presents thorough experimental and numerical investigations of one isothermal and two reacting turbulent opposed jets with fuel jets consisting of partially premixed methane. Its focus is on one configuration at and one configuration close to the highest possible Reynolds numbers where flames could be stabilized. The experimental data presented comprise information on axial velocity, main species concentrations, temperature, mixture fraction, scalar dissipation rate, joint probability density functions, and structure functions. These quantities are compared to results of highly resolved CLES to show the configuration's suitability as a critical benchmark for state-of-the art combustion LES.

  14. [Critical review of 222 cases of neoplastic pathology of the colon. Our experience using a computer].

    PubMed

    Parrella, R E; Astore, S; Brizi, M G; Natale, L; Pagano, A; Posi, G

    1987-11-01

    From August 1983 to December 1985, 2352 radiological examinations of the colon were performed in the Radiology Department of Università Cattolica del Sacro Cuore of Rome. From this group a sample of 222 patients was analyzed. They included 111 patients with colonic polyps and 111 with cancer. These cases were carefully examined, in terms of age, frequency of this pathology according to sex, symptom-illness rate, and the radiological data were compared with the endoscopic and histological findings. The data were processed using a computerized program. A critical correlation of the data obtained revealed that: 1) The surest symptom of colon carcinoma is blood in faeces with or without changes in defaecation frequency. Nor should isolated bowel disorders be ignored ("irritated" colon due to organic injuries). 2) The diagnostic accuracy of double contrast enema is very close to that of endoscopy, provided that intestinal cleaning is adequate (this in fact is an important aspect of the examination). 3) The mean age of patients in this group is high and cancer is more common than polyps. This seems to be due to the back of a complete diagnostic sequence, in which radiology has a specific and important role.

  15. Analysis and evaluation of ZPPR (Zero Power Physics Reactor) critical experiments for a 100 kilowatt-electric space reactor

    SciTech Connect

    McFarlane, H.F.; Collins, P.J.; Carpenter, S.G.; Olsen, D.N.; Smith, D.M.; Schaefer, R.W. ); Doncals, R.A.; Andre, S.V.; Porter, C.A. ); Cowan, C.L; Stewart, S.L.; Protsik, R. . Astro Space Div.)

    1990-01-01

    ZPPR critical experiments were used for physics testing the reactor design of the SP-100, a 100-kW thermoelectric LMR that is being developed to provide electrical power for space applications. These tests validated all key physics characteristics of the design, including the ultimate safety in the event of a launch or re-entry accident. Both the experiments and the analysis required the use of techniques not previously applied to fast reactor designs. A few significant discrepancies between the experimental and calculated results leave opportunities for further optimization. An initial investigation has been made into application of the ZPPR-20 results, along with those of other relevant integral data, to the SP-100 design. 13 refs., 5 figs., 7 tabs.

  16. Recent UCN source developments at Los Alamos

    SciTech Connect

    Seestrom, S.J.; Anaya, J.M.; Bowles, T.J.

    1998-12-01

    The most intense sources of ultra cold neutrons (UCN) have bee built at reactors where the high average thermal neutron flux can overcome the low UCN production rate to achieve usable densities of UCN. At spallation neutron sources the average flux available is much lower than at a reactor, though the peak flux can be comparable or higher. The authors have built a UCN source that attempts to take advantage of the high peak flux available at the short pulse spallation neutron source at the Los Alamos Neutron Science Center (LANSCE) to generate a useful number of UCN. In the source UCN are produced by Doppler-shifted Bragg scattering of neutrons to convert 400-m/s neutrons down into the UCN regime. This source was initially tested in 1996 and various improvements were made based on the results of the 1996 running. These improvements were implemented and tested in 1997. In sections 2 and 3 they discuss the improvements that have been made and the resulting source performance. Recently an even more interesting concept was put forward by Serebrov et al. This involves combining a solid Deuterium UCN source, previously studied by Serebrov et al., with a pulsed spallation source to achieve world record UCN densities. They have initiated a program of calculations and measurements aimed at verifying the solid Deuterium UCN source concept. The approach has been to develop an analytical capability, combine with Monte Carlo calculations of neutron production, and perform benchmark experiments to verify the validity of the calculations. Based on the calculations and measurements they plan to test a modified version of the Serebrov UCN factory. They estimate that they could produce over 1,000 UCN/cc in a 15 liter volume, using 1 {micro}amp of 800 MeV protons for two seconds every 500 seconds. They will discuss the result UCN production measurements in section 4.

  17. SEDs at Los Alamos: A Personal Memoir

    NASA Astrophysics Data System (ADS)

    Bederson, Benjamin

    2001-03-01

    I have written this personal memoir approximately 55 years after the events I describe. It is based almost exclusively on memory, since apart from the diary I kept while on Tinian, I have few documents concerning it. It covers my service in the U.S. Army's Special Engineering Detachment (SED) in Oak Ridge and Los Alamos in 1944-45, on Tinian island, the launching pad for the bombing raids on Japan, in the summer and fall of 1945, and my return to Los Alamos until my discharge in January 1946.

  18. Designing phase 3 sepsis trials: application of learned experiences from critical care trials in acute heart failure.

    PubMed

    Mebazaa, Alexandre; Laterre, Pierre François; Russell, James A; Bergmann, Andreas; Gattinoni, Luciano; Gayat, Etienne; Harhay, Michael O; Hartmann, Oliver; Hein, Frauke; Kjolbye, Anne Louise; Legrand, Matthieu; Lewis, Roger J; Marshall, John C; Marx, Gernot; Radermacher, Peter; Schroedter, Mathias; Scigalla, Paul; Stough, Wendy Gattis; Struck, Joachim; Van den Berghe, Greet; Yilmaz, Mehmet Birhan; Angus, Derek C

    2016-01-01

    Substantial attention and resources have been directed to improving outcomes of patients with critical illnesses, in particular sepsis, but all recent clinical trials testing various interventions or strategies have failed to detect a robust benefit on mortality. Acute heart failure is also a critical illness, and although the underlying etiologies differ, acute heart failure and sepsis are critical care illnesses that have a high mortality in which clinical trials have been difficult to conduct and have not yielded effective treatments. Both conditions represent a syndrome that is often difficult to define with a wide variation in patient characteristics, presentation, and standard management across institutions. Referring to past experiences and lessons learned in acute heart failure may be informative and help frame research in the area of sepsis. Academic heart failure investigators and industry have worked closely with regulators for many years to transition acute heart failure trials away from relying on dyspnea assessments and all-cause mortality as the primary measures of efficacy, and recent trials have been designed to assess novel clinical composite endpoints assessing organ dysfunction and mortality while still assessing all-cause mortality as a separate measure of safety. Applying the lessons learned in acute heart failure trials to severe sepsis and septic shock trials might be useful to advance the field. Novel endpoints beyond all-cause mortality should be considered for future sepsis trials. PMID:27034779

  19. Defect printability of ArF alternative phase-shift mask: a critical comparison of simulation and experiment

    NASA Astrophysics Data System (ADS)

    Ozawa, Ken; Komizo, Tooru; Ohnuma, Hidetoshi

    2002-07-01

    An alternative phase shift mask (alt-PSM) is a promising device for extending optical lithography to finer design rules. There have been few reports, however, on the mask's ability to identify phase defects. We report here an alt-PSM of a single-trench type with undercut for ArF exposure, with programmed phase defects used to evaluate defect printability by measuring aerial images with a Zeiss MSM193 measuring system. The experimental results are simulated using the TEMPEST program. First, a critical comparison of the simulation and the experiment is conducted. The actual measured topographies of quartz defects are used in the simulation. Moreover, a general simulation study on defect printability using an alt-PSM for ArF exposure is conducted. The defect dimensions, which produce critical CD errors, are determined by simulation that takes into account the full 3-dimensional structure of phase defects as well as a simplified structure. The critical dimensions of an isolated bump defect identified by the alt-PSM of a single-trench type with undercut for ArF exposure are 300 nm in bottom dimension and 74 degrees in height (phase) for the real shape, where the depth of wet-etching is 100 nm and the CD error limit is +/- 5 percent.

  20. Three-Dimensional Electromagnetic Monte Carlo Particle-in-Cell Simulations of Critical Ionization Velocity Experiments in Space

    NASA Technical Reports Server (NTRS)

    Wang, J.; Biasca, R.; Liewer, P. C.

    1996-01-01

    Although the existence of the critical ionization velocity (CIV) is known from laboratory experiments, no agreement has been reached as to whether CIV exists in the natural space environment. In this paper we move towards more realistic models of CIV and present the first fully three-dimensional, electromagnetic particle-in-cell Monte-Carlo collision (PIC-MCC) simulations of typical space-based CIV experiments. In our model, the released neutral gas is taken to be a spherical cloud traveling across a magnetized ambient plasma. Simulations are performed for neutral clouds with various sizes and densities. The effects of the cloud parameters on ionization yield, wave energy growth, electron heating, momentum coupling, and the three-dimensional structure of the newly ionized plasma are discussed. The simulations suggest that the quantitative characteristics of momentum transfers among the ion beam, neutral cloud, and plasma waves is the key indicator of whether CIV can occur in space. The missing factors in space-based CIV experiments may be the conditions necessary for a continuous enhancement of the beam ion momentum. For a typical shaped charge release experiment, favorable CIV conditions may exist only in a very narrow, intermediate spatial region some distance from the release point due to the effects of the cloud density and size. When CIV does occur, the newly ionized plasma from the cloud forms a very complex structure due to the combined forces from the geomagnetic field, the motion induced emf, and the polarization. Hence the detection of CIV also critically depends on the sensor location.

  1. Radio-induced gliomas: 20-year experience and critical review of the pathology.

    PubMed

    Salvati, Maurizio; D'Elia, Alessandro; Melone, Graziella Angelina; Brogna, Christian; Frati, Alessandro; Raco, Antonino; Delfini, Roberto

    2008-09-01

    The authors report their personal experience with a surgical series of 16 cases of cerebral radiation-induced gliomas, defining diagnostic criteria and surgical and clinical characteristics. There were ten males and six females, with a median age of 45.9 years. Irradiation had initially been given for acute lymphoblastic leukemia (ALL) in six cases, tinea capitis in four cases, scalp hemangioma in three cases, cutaneous hemangioma, cavernous angioma, and medulloblastoma in one case each. There were 14 cases of glioblastoma (grade IV WHO) and 2 cases of astrocytoma (grade II WHO), with a mean latency time of 17 years (range: 6-26 years). For glioblastomas mean survival time was 10.4 months, accounting for 1-3% of all the glioblastomas treated. A thorough revision of the pertinent literature revealed some clinical-biological peculiarities.

  2. ENDF/B-VII.1 Neutron Cross Section Data Testing with Critical Assembly Benchmarks and Reactor Experiments

    SciTech Connect

    Kahler, A.; Macfarlane, R E; Mosteller, R D; Kiedrowski, B C; Frankle, S C; Chadwick, M. B.; Mcknight, R D; Lell, R M; Palmiotti, G; Hiruta, h; Herman, Micheal W; Arcilla, r; Mughabghab, S F; Sublet, J C; Trkov, A.; Trumbull, T H; Dunn, Michael E

    2011-01-01

    The ENDF/B-VII.1 library is the latest revision to the United States' Evaluated Nuclear Data File (ENDF). The ENDF library is currently in its seventh generation, with ENDF/B-VII.0 being released in 2006. This revision expands upon that library, including the addition of new evaluated files (was 393 neutron files previously, now 423 including replacement of elemental vanadium and zinc evaluations with isotopic evaluations) and extension or updating of many existing neutron data files. Complete details are provided in the companion paper [1]. This paper focuses on how accurately application libraries may be expected to perform in criticality calculations with these data. Continuous energy cross section libraries, suitable for use with the MCNP Monte Carlo transport code, have been generated and applied to a suite of nearly one thousand critical benchmark assemblies defined in the International Criticality Safety Benchmark Evaluation Project's International Handbook of Evaluated Criticality Safety Benchmark Experiments. This suite covers uranium and plutonium fuel systems in a variety of forms such as metallic, oxide or solution, and under a variety of spectral conditions, including unmoderated (i.e., bare), metal reflected and water or other light element reflected. Assembly eigenvalues that were accurately predicted with ENDF/B-VII.0 cross sections such as unrnoderated and uranium reflected (235)U and (239)Pu assemblies, HEU solution systems and LEU oxide lattice systems that mimic commercial PWR configurations continue to be accurately calculated with ENDF/B-VII.1 cross sections, and deficiencies in predicted eigenvalues for assemblies containing selected materials, including titanium, manganese, cadmium and tungsten are greatly reduced. Improvements are also confirmed for selected actinide reaction rates such as (236)U; (238,242)Pu and (241,243)Am capture in fast systems. Other deficiencies, such as the overprediction of Pu solution system critical eigenvalues

  3. ENDF/B-VII.1 Neutron Cross Section Data Testing with Critical Assembly Benchmarks and Reactor Experiments

    SciTech Connect

    G. Palmiotti

    2011-12-01

    The ENDF/B-VII.1 library is the latest revision to the United States' Evaluated Nuclear Data File (ENDF). The ENDF library is currently in its seventh generation, with ENDF/B-VII.0 being released in 2006. This revision expands upon that library, including the addition of new evaluated files (was 393 neutron files previously, now 418 including replacement of elemental vanadium and zinc evaluations with isotopic evaluations) and extension or updating of many existing neutron data files. Complete details are provided in the companion paper [1]. This paper focuses on how accurately application libraries may be expected to perform in criticality calculations with these data. Continuous energy cross section libraries, suitable for use with the MCNP Monte Carlo transport code, have been generated and applied to a suite of nearly one thousand critical benchmark assemblies defined in the International Criticality Safety Benchmark Evaluation Project's International Handbook of Evaluated Criticality Safety Benchmark Experiments. This suite covers uranium and plutonium fuel systems in a variety of forms such as metallic, oxide or solution, and under a variety of spectral conditions, including unmoderated (i.e., bare), metal reflected and water or other light element reflected. Assembly eigenvalues that were accurately predicted with ENDF/B-VII.0 cross sections such as unmoderated and uranium reflected 235U and 239Pu assemblies, HEU solution systems and LEU oxide lattice systems that mimic commercial PWR configurations continue to be accurately calculated with ENDF/B-VII.1 cross sections, and deficiencies in predicted eigenvalues for assemblies containing selected materials, including titanium, manganese, cadmium and tungsten are greatly reduced. Improvements are also confirmed for selected actinide reaction rates such as 236U capture. Other deficiencies, such as the overprediction of Pu solution system critical eigenvalues and a decreasing trend in calculated eigenvalue for

  4. ENDF/B-VII.1 Neutron Cross Section Data Testing with Critical Assembly Benchmarks and Reactor Experiments

    SciTech Connect

    Kahler, A.C.; Herman, M.; Kahler,A.C.; MacFarlane,R.E.; Mosteller,R.D.; Kiedrowski,B.C.; Frankle,S.C.; Chadwick,M.B.; McKnight,R.D.; Lell,R.M.; Palmiotti,G.; Hiruta,H.; Herman,M.; Arcilla,R.; Mughabghab,S.F.; Sublet,J.C.; Trkov,A.; Trumbull,T.H.; Dunn,M.

    2011-12-01

    The ENDF/B-VII.1 library is the latest revision to the United States Evaluated Nuclear Data File (ENDF). The ENDF library is currently in its seventh generation, with ENDF/B-VII.0 being released in 2006. This revision expands upon that library, including the addition of new evaluated files (was 393 neutron files previously, now 423 including replacement of elemental vanadium and zinc evaluations with isotopic evaluations) and extension or updating of many existing neutron data files. Complete details are provided in the companion paper [M. B. Chadwick et al., 'ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data,' Nuclear Data Sheets, 112, 2887 (2011)]. This paper focuses on how accurately application libraries may be expected to perform in criticality calculations with these data. Continuous energy cross section libraries, suitable for use with the MCNP Monte Carlo transport code, have been generated and applied to a suite of nearly one thousand critical benchmark assemblies defined in the International Criticality Safety Benchmark Evaluation Project's International Handbook of Evaluated Criticality Safety Benchmark Experiments. This suite covers uranium and plutonium fuel systems in a variety of forms such as metallic, oxide or solution, and under a variety of spectral conditions, including unmoderated (i.e., bare), metal reflected and water or other light element reflected. Assembly eigenvalues that were accurately predicted with ENDF/B-VII.0 cross sections such as unmoderated and uranium reflected {sup 235}U and {sup 239}Pu assemblies, HEU solution systems and LEU oxide lattice systems that mimic commercial PWR configurations continue to be accurately calculated with ENDF/B-VII.1 cross sections, and deficiencies in predicted eigenvalues for assemblies containing selected materials, including titanium, manganese, cadmium and tungsten are greatly reduced. Improvements are also confirmed for

  5. ENDF/B-VII.1 Neutron Cross Section Data Testing with Critical Assembly Benchmarks and Reactor Experiments

    NASA Astrophysics Data System (ADS)

    Kahler, A. C.; MacFarlane, R. E.; Mosteller, R. D.; Kiedrowski, B. C.; Frankle, S. C.; Chadwick, M. B.; McKnight, R. D.; Lell, R. M.; Palmiotti, G.; Hiruta, H.; Herman, M.; Arcilla, R.; Mughabghab, S. F.; Sublet, J. C.; Trkov, A.; Trumbull, T. H.; Dunn, M.

    2011-12-01

    The ENDF/B-VII.1 library is the latest revision to the United States' Evaluated Nuclear Data File (ENDF). The ENDF library is currently in its seventh generation, with ENDF/B-VII.0 being released in 2006. This revision expands upon that library, including the addition of new evaluated files (was 393 neutron files previously, now 423 including replacement of elemental vanadium and zinc evaluations with isotopic evaluations) and extension or updating of many existing neutron data files. Complete details are provided in the companion paper [M. B. Chadwick et al., "ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data," Nuclear Data Sheets, 112, 2887 (2011)]. This paper focuses on how accurately application libraries may be expected to perform in criticality calculations with these data. Continuous energy cross section libraries, suitable for use with the MCNP Monte Carlo transport code, have been generated and applied to a suite of nearly one thousand critical benchmark assemblies defined in the International Criticality Safety Benchmark Evaluation Project's International Handbook of Evaluated Criticality Safety Benchmark Experiments. This suite covers uranium and plutonium fuel systems in a variety of forms such as metallic, oxide or solution, and under a variety of spectral conditions, including unmoderated (i.e., bare), metal reflected and water or other light element reflected. Assembly eigenvalues that were accurately predicted with ENDF/B-VII.0 cross sections such as unmoderated and uranium reflected 235U and 239Pu assemblies, HEU solution systems and LEU oxide lattice systems that mimic commercial PWR configurations continue to be accurately calculated with ENDF/B-VII.1 cross sections, and deficiencies in predicted eigenvalues for assemblies containing selected materials, including titanium, manganese, cadmium and tungsten are greatly reduced. Improvements are also confirmed for selected

  6. Industrial application for the Los Alamos Materials Modeling Platform

    SciTech Connect

    Lesar, R.; Charbon, C.; Kothe, D.; Wu, D.; Reddy, A.

    1996-09-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Casting and solidification of molten metals and metal alloys is a critical step in the production of high-quality metal stock and in the fabrication of finished parts. Control of the casting process can be the determining factor in both the quality and cost of the final metal product. Major problems with the quality of cast stock or finished parts can arise because of the difficulty of preventing variations in the alloy content, the generation of porosity or poor surface finish, and the loss of microstructure controlled strength and toughness resulting from the poor understanding and design of the mold filling and solidification processes. In this project, we sought to develop a new set of applications focused on adding the ability to accurately model solidification and grain growth to casting simulations. We implemented these applications within the Los Alamos Materials Modeling Platform, LAMMP, a graphical-based materials, and materials modeling environment being created at the Computational Testbed for Industry.

  7. Experiences with Extra-Vehicular Activities in Response to Critical ISS Contingencies

    NASA Technical Reports Server (NTRS)

    Van Cise, E. A.; Kelly, B. J.; Radigan, J. P.; Cranmer, C. W.

    2016-01-01

    Contingency EVA preparation team structure, approach, goals, and the resources allocated to its work after the 2010 events. Finally, the authors will overview the implementation of these updates in addressing failures onboard the ISS in 2012, 2013, and 2014. The successful use of the updated approaches, and the application of the approaches to other spacewalks, will demonstrate the effectiveness of this additional work and make a case for putting significant time and resources into pre-failure planning and analysis for critical hardware items on human-tended spacecraft.

  8. Experiences with Extra-Vehicular Activities in Response to Critical ISS Contingencies

    NASA Technical Reports Server (NTRS)

    Van Cise, E. A.; Kelly, B. J.; Radigan, J. P.; Cranmer, C. W.

    2016-01-01

    EVA preparation team structure, approach, goals, and the resources allocated to its work after the 2010 events. Finally, the authors will overview the implementation of these updates in addressing failures onboard the ISS in 2012, 2013, and 2014. The successful use of the updated approaches, and the application of the approaches to other spacewalks, will demonstrate the effectiveness of this additional work and make a case for putting significant time and resources into pre-failure planning and analysis for critical hardware items on human-tended spacecraft.

  9. RCRA facility investigation for the townsite of Los Alamos, New Mexico

    SciTech Connect

    Dorries, A.M.; Conrad, R.C.; Nonno, L.M.

    1992-01-01

    During World War II, Los Alamos, New Mexico was established as an ideal location for the secrecy and safety needed for the research and development required to design a nuclear fission bomb. Experiments carried out in the 1940s generated both radioactive and hazardous waste constituents on what is presently part of the Los Alamos townsite. Under the RCRA permit issued to Los alamos national Laboratory in 1990, the Laboratory is scheduled for investigation of its solid waste management units (SWMUs). The existing information on levels of radioactivity on the townsite is principally data from soil samples taken during the last site decontamination in 1976, little information on the presence of hazardous constituents exists today. This paper addresses pathway analysis and a preliminary risk assessment for current residents of the Los Alamos townsite. The estimated dose levels, in mrem per year, show that the previously decontaminated SWMU areas on the Los Alamos townsite will not contribute a radiation dose of any concern to the current residents.

  10. RCRA facility investigation for the townsite of Los Alamos, New Mexico

    SciTech Connect

    Dorries, A.M.; Conrad, R.C.; Nonno, L.M.

    1992-02-01

    During World War II, Los Alamos, New Mexico was established as an ideal location for the secrecy and safety needed for the research and development required to design a nuclear fission bomb. Experiments carried out in the 1940s generated both radioactive and hazardous waste constituents on what is presently part of the Los Alamos townsite. Under the RCRA permit issued to Los alamos national Laboratory in 1990, the Laboratory is scheduled for investigation of its solid waste management units (SWMUs). The existing information on levels of radioactivity on the townsite is principally data from soil samples taken during the last site decontamination in 1976, little information on the presence of hazardous constituents exists today. This paper addresses pathway analysis and a preliminary risk assessment for current residents of the Los Alamos townsite. The estimated dose levels, in mrem per year, show that the previously decontaminated SWMU areas on the Los Alamos townsite will not contribute a radiation dose of any concern to the current residents.

  11. Los Alamos Controlled Air Incinerator for radioactive waste. Volume II. Engineering design reference manual

    SciTech Connect

    Koenig, R.A.; Draper, W.E.; Newmyer, J.M.; Warner, C.L.

    1982-10-01

    This two-volume report is a detailed design and operating documentation of the Los Alamos National Laboratory Controlled Air Incinerator (CAI) and is an aid to technology transfer to other Department of Energy contractor sites and the commercial sector. Volume I describes the CAI process, equipment, and performance, and it recommends modifications based on Los Alamos experience. It provides the necessary information for conceptual design and feasibility studies. Volume II provides descriptive engineering information such as drawings, specifications, calculations, and costs. It aids duplication of the process at other facilities.

  12. Validation of the SCALE code system using criticality data from experiments performed with Pu + U solutions in cylindrical and slab geometry

    SciTech Connect

    Smolen, G.R.; Funabashi, H.

    1988-01-01

    This paper outlines the results of a calculational study that was performed to validate two versions of the SCALE computer code system using data from critical experiments performed with mixed Pu + U aqueous solutions. The critical experiments were conducted in a 35-cm-diam cylinder and variable thickness slab tank. A companion paper reports on the criticality data that was obtained. These experimental activities are part of a joint exchange program between the US Department of Energy (USDOE) and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan in the area of criticality data development. The Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) manages the program for the USDOE. The experiments were conducted at the Battelle Pacific Northwest Laboratories-Critical Mass Laboratory (PNL-CML). 5 refs., 1 fig., 1 tab.

  13. Exploding metallic foil fuse modeling at Los Alamos

    SciTech Connect

    Lindemuth, I.R.; Reinovsky, R.E.; Goforth, J.H.

    1989-01-01

    A ''first-principles'' computational model of exploding metallic foil behavior has been developed at Los Alamos. The model couples zero-dimensional magnetohydrodynamics with ohmic heating and electrical circuit equations and uses the Los Alamos SESAME atomic data base computer library to determine the foil material's temperature- and density-dependent pressure, specific energy, and electrical conductivity. The model encompasses many previously successful empirical models and offers plausible physical explanations of phenomena not treated by the empirical models. In addition to addressing the electrical circuit performance of an exploding foil, the model provides information on the temporal evolution of the foil material's density, temperature, pressure, electrical conductivity, and expansion and translational velocities. In this paper, we report the physical insight gained by computational studies of two opening switch concepts being developed for application in an FCG-driven 1-MJ-class imploding plasma z-pinch experiment. The first concept considered is a ''conventional'' electrically exploded fuse, which has been demonstrated to operate at 16 MA driven by the 15-MJ-class FCG to be used in the 1 MJ implosion experiment. The second concept considered is a Type 2 explosively formed fuse (EFF), which has been demonstrated to operate at the 8 MA level by a 1-MJ-class FCG.

  14. Exploding metallic foil fuse modeling at Los Alamos

    NASA Astrophysics Data System (ADS)

    Lindemuth, Irvin R.; Reinovsky, Robert E.; Goforth, James H.

    A first-principles computational model of exploding metallic foil behavior was developed at Los Alamos. The model couples zero-dimensional magnetohydrodynamics with ohmic heating and electrical circuit equations and uses the Los Alamos SESAME atomic data base computer library to determine the foil material's temperature- and density-dependent pressure, specific energy, and electrical conductivity. The model encompasses many previously successful empirical models and offers plausible physical explanations of phenomena not treated by the empirical models. In addition to addressing the electrical circuit performance of an exploding foil, the model provides information on the temporal evolution of the foil material's density, temperature, pressure, electrical conductivity, and expansion and translational velocities. The physical insight gained by computational studies of two opening switch concepts being developed for application in an FCG-driven 1-MJ-class imploding plasma z-pinch experiment are reported. The first concept considered is a conventional electrically exploded fuse, which was demonstrated to operate at 16 MA driven by the 15-MJ-class FCG to be used in the 1 MJ implosion experiment. The second concept considered is a Type 2 explosively formed fuse (EFF), which was demonstrated to operate at the 8 MA level by a 1-MJ-class FCG.

  15. Quantifying critical conditions for seaward expansion of tidal marshes: A transplantation experiment

    NASA Astrophysics Data System (ADS)

    Silinski, Alexandra; van Belzen, Jim; Fransen, Erik; Bouma, Tjeerd J.; Troch, Peter; Meire, Patrick; Temmerman, Stijn

    2016-02-01

    The alternative stable states theory is increasingly applied to tidal marsh shorelines, where the two opposing stable states - a dense vegetated state on the one hand and a bare tidal flat on the other hand - can coexist in time but differ in space. The shift from the bare to vegetated state by the establishment of individual plants (seedlings, rhizome-grown shoots) on the bare tidal flat is known to be triggered by the occurrence of windows of opportunity. These are periods when species- and life stage-dependent thresholds, such as sediment dynamics or wave impact, are not exceeded. One controlling environmental parameter in intertidal wetlands is elevation as many important stressors for plants - such as hydroperiod, sediment dynamics and wave properties (wave period and wave height) - are typically correlated to it. Disentangling the respective impact of these correlated stressors remains challenging. In this paper, we present the results of a transplantation experiment where the establishment of three different life stages (seedlings, rhizome-grown shoots and patches) of the brackish pioneer Scirpus maritimus was tested over an elevation gradient at two locations of contrasting wave exposure. This gradient reached from the bare tidal flat into the marsh and covered an elevation range at which continuous S. maritimus-dominated pioneer marsh is known to occur. We found that erosion stress influences seedling survival on tidal flats while drought stress seems to limit long-term establishment of individual shoots and seedlings in the marsh. Furthermore, survival of transplants was more successful on the tidal flat of the sheltered site compared to the tidal flat of the exposed site whereas survival time within the marsh did not differ between sites. This highlights the attenuation of waves and currents in exposed marshes. However, no long-term establishment occurred on the tidal flat, emphasizing the importance of clonal integration for tidal flat colonization.

  16. Induction inserts at the Los Alamos PSR

    SciTech Connect

    King-Yuen Ng

    2002-09-30

    Ferrite-loaded induction tuners installed in the Los Alamos Proton Storage Ring have been successful in compensating space-charge effects. However, the resistive part of the ferrite introduces unacceptable microwave instability and severe bunch lengthening. An effective cure was found by heating the ferrite cores up to {approx} 130 C. An understanding of the instability and cure is presented.

  17. Los Alamos waste drum shufflers users manual

    SciTech Connect

    Rinard, P.M.; Adams, E.L.; Painter, J.

    1993-08-24

    This user manual describes the Los Alamos waste drum shufflers. The primary purpose of the instruments is to assay the mass of {sup 235}U (or other fissile materials) in drums of assorted waste. It can perform passive assays for isotopes that spontaneously emit neutrons or active assays using the shuffler technique as described on this manual.

  18. Proceedings of the Los Alamos neutrino workshop

    SciTech Connect

    Boehm, F.; Stephenson, G.J. Jr.

    1982-08-01

    A workshop on neutrino physics was held at Los Alamos from June 8 to 12, 1981. The material presented has been provided in part by the organizers, in part by the chairmen of the working sessions. Closing date for contributions was October 1981.

  19. "A Moving Target": A Critical Race Analysis of Latina/o Faculty Experiences, Perspectives, and Reflections on the Tenure and Promotion Process

    ERIC Educational Resources Information Center

    Urrieta, Luis, Jr.; Méndez, Lina; Rodríguez, Esmeralda

    2015-01-01

    This article examines how Latina/o professors perceive, experience, and reflect on the tenure and promotion process. Findings for this longitudinal study are drawn from a purposive sample of nine female and seven male, Latina/o tenure-track faculty participants. Using a Critical Race Theory, Latino Critical (LatCrit) Race Theory, and Chicana…

  20. Los Alamos Fires From Landsat 7

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On May 9, 2000, the Landsat 7 satellite acquired an image of the area around Los Alamos, New Mexico. The Landsat 7 satellite acquired this image from 427 miles in space through its sensor called the Enhanced Thematic Mapper Plus (ETM+). Evident within the imagery is a view of the ongoing Cerro Grande fire near the town of Los Alamos and the Los Alamos National Laboratory. Combining the high-resolution (30 meters per pixel in this scene) imaging capacity of ETM+ with its multi-spectral capabilities allows scientists to penetrate the smoke plume and see the structure of the fire on the surface. Notice the high-level of detail in the infrared image (bottom), in which burn scars are clearly distinguished from the hotter smoldering and flaming parts of the fire. Within this image pair several features are clearly visible, including the Cerro Grande fire and smoke plume, the town of Los Alamos, the Los Alamos National Laboratory and associated property, and Cerro Grande peak. Combining ETM+ channels 7, 4, and 2 (one visible and two infrared channels) results in a false color image where vegetation appears as bright to dark green (bottom image). Forested areas are generally dark green while herbaceous vegetation is light green. Rangeland or more open areas appear pink to light purple. Areas with extensive pavement or urban development appear light blue or white to purple. Less densely-developed residential areas appear light green and golf courses are very bright green. The areas recently burned appear black. Dark red to bright red patches, or linear features within the burned area, are the hottest and possibly actively burning areas of the fire. The fire is spreading downslope and the front of the fire is readily detectable about 2 kilometers to the west and south of Los Alamos. Combining ETM+ channels 3, 2, and 1 provides a true-color image of the greater Los Alamos region (top image). Vegetation is generally dark to medium green. Forested areas are very dark green

  1. Critical Plastic Strain as a Criterion for Failure in Ballistic Impact Experiments of U/Ti and Ti64 Alloys

    NASA Astrophysics Data System (ADS)

    Herrmann, B.; Favorsky, V.; Zaretsky, E.; Shvarts, D.

    2006-07-01

    Strain localization and failure in U-0.75Ti and Ti-6Al-4V alloys were studied in symmetric (rod-on-rod) and reverse ballistic (disk-on-rod) impact experiments, accompanied by VISAR monitoring of the lateral sample surface velocity. Softly-recovered samples were metallurgically examined, and the experiments were numerically simulated using an AUTODYN™ 2-D code. Satisfactory reproduction of both the measured velocity profiles and the results of metallographic examination of the damage produced by adiabatic shearing were obtained by using the Steinberg-Cochran-Guinan-type constitutive equation (calibrated in preliminary planar impact experiments) and the AUTODYN™ built-in erosion function. A good agreement was found between strains, measured by using natural markers (martensite in U/Ti and texture in Ti64), corresponding to the onset of adiabatic shearing (0.5 - 1.0) and the value of the critical plastic strain used in the simulations as a criterion for triggering the erosion function (0.6 for both alloys). In the case of Ti64 the shearing is finalized by cracking at observed strain values of 1.0 - 1.5, whereas in the U/Ti the shear strain reaches values greater by at least one order of magnitude and is terminated by void growth and coalescence.

  2. INTEGRAL BENCHMARKS AVAILABLE THROUGH THE INTERNATIONAL REACTOR PHYSICS EXPERIMENT EVALUATION PROJECT AND THE INTERNATIONAL CRITICALITY SAFETY BENCHMARK EVALUATION PROJECT

    SciTech Connect

    J. Blair Briggs; Lori Scott; Enrico Sartori; Yolanda Rugama

    2008-09-01

    Interest in high-quality integral benchmark data is increasing as efforts to quantify and reduce calculational uncertainties accelerate to meet the demands of next generation reactor and advanced fuel cycle concepts. The International Reactor Physics Experiment Evaluation Project (IRPhEP) and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) continue to expand their efforts and broaden their scope to identify, evaluate, and provide integral benchmark data for method and data validation. Benchmark model specifications provided by these two projects are used heavily by the international reactor physics, nuclear data, and criticality safety communities. Thus far, 14 countries have contributed to the IRPhEP, and 20 have contributed to the ICSBEP. The status of the IRPhEP and ICSBEP is discussed in this paper, and the future of the two projects is outlined and discussed. Selected benchmarks that have been added to the IRPhEP and ICSBEP handbooks since PHYSOR’06 are highlighted, and the future of the two projects is discussed.

  3. Validation of multigroup neutron cross sections and calculational methods for the advanced neutron source against the FOEHN critical experiments measurements

    SciTech Connect

    Smith, L.A.; Gallmeier, F.X.; Gehin, J.C.

    1995-05-01

    The FOEHN critical experiment was analyzed to validate the use of multigroup cross sections and Oak Ridge National Laboratory neutronics computer codes in the design of the Advanced Neutron Source. The ANSL-V 99-group master cross section library was used for all the calculations. Three different critical configurations were evaluated using the multigroup KENO Monte Carlo transport code, the multigroup DORT discrete ordinates transport code, and the multigroup diffusion theory code VENTURE. The simple configuration consists of only the fuel and control elements with the heavy water reflector. The intermediate configuration includes boron endplates at the upper and lower edges of the fuel element. The complex configuration includes both the boron endplates and components in the reflector. Cross sections were processed using modules from the AMPX system. Both 99-group and 20-group cross sections were created and used in two-dimensional models of the FOEHN experiment. KENO calculations were performed using both 99-group and 20-group cross sections. The DORT and VENTURE calculations were performed using 20-group cross sections. Because the simple and intermediate configurations are azimuthally symmetric, these configurations can be explicitly modeled in R-Z geometry. Since the reflector components cannot be modeled explicitly using the current versions of these codes, three reflector component homogenization schemes were developed and evaluated for the complex configuration. Power density distributions were calculated with KENO using 99-group cross sections and with DORT and VENTURE using 20-group cross sections. The average differences between the measured values and the values calculated with the different computer codes range from 2.45 to 5.74%. The maximum differences between the measured and calculated thermal flux values for the simple and intermediate configurations are {approx} 13%, while the average differences are < 8%.

  4. Is a good death possible in Australian critical and acute settings?: physician experiences with end-of-life care

    PubMed Central

    2014-01-01

    Background In Australia approximately 70% of all deaths are institutionalised but over 15% of deaths occur in intensive care settings where the ability to provide a “good death” is particularly inhibited. Yet, there is a growing trend for death and dying to be managed in the ICU and physicians are increasingly challenged to meet the new expectations of their specialty. This study examined the unexplored interface between specialised Australian palliative and intensive care and the factors influencing a physician’s ability to manage deaths well. Method A qualitative investigation was focused on palliative and critical/acute settings. A thematic analysis was conducted on semi-structured in-depth interviews with 13 specialist physicians. Attention was given to eliciting meanings and experiences in Australian end-of-life care. Results Physicians negotiated multiple influences when managing dying patients and their families in the ICU. The way they understood and experienced end-of-life care practices was affected by cultural, institutional and professional considerations, and personal values and beliefs. Interpersonal and intrapsychic aspects highlighted the emotional and psychological relationship physicians have with patients and others. Many physicians were also unaware of what their cross-disciplinary colleagues could or could not do; poor professional recognition and collaboration, and ineffective care goal transition impaired their ability to assist good deaths. Experience was subject to the efficacy of physicians in negotiating complex bedside dynamics. Conclusions Regardless of specialty, all physicians identified the problematic nature of providing expert palliation in critical and acute settings. Strategies for integrating specialised palliative and intensive care were offered with corresponding directions for future research and clinical development. PMID:25147481

  5. Hydrologic transport of depleted uranium associated with open air dynamic range testing at Los Alamos National Laboratory, New Mexico, and Eglin Air Force Base, Florida

    SciTech Connect

    Becker, N.M.; Vanta, E.B.

    1995-05-01

    Hydrologic investigations on depleted uranium fate and transport associated with dynamic testing activities were instituted in the 1980`s at Los Alamos National Laboratory and Eglin Air Force Base. At Los Alamos, extensive field watershed investigations of soil, sediment, and especially runoff water were conducted. Eglin conducted field investigations and runoff studies similar to those at Los Alamos at former and active test ranges. Laboratory experiments complemented the field investigations at both installations. Mass balance calculations were performed to quantify the mass of expended uranium which had transported away from firing sites. At Los Alamos, it is estimated that more than 90 percent of the uranium still remains in close proximity to firing sites, which has been corroborated by independent calculations. At Eglin, we estimate that 90 to 95 percent of the uranium remains at test ranges. These data demonstrate that uranium moves slowly via surface water, in both semi-arid (Los Alamos) and humid (Eglin) environments.

  6. Los Alamos Guns Take Aim at Material's Mysteries

    SciTech Connect

    Byers, Mark; Moore, David; Dimarino, Steve

    2014-04-14

    Los Alamos National Laboratory scientists and technicians conduct thousands of experiments a year, delving into the fundamental nature of everything from supernovas to subatomic particles. One set of instruments used to better understand the fundamental nature of various materials are 10 scientific gun systems that fire various projectiles at high-tech targets to create enormous velocities, pressures, and temperatures - and using laser, x-ray, and other diagnostics - explore the very nature of metals and other materials. The hundreds of gun-based experiments conducted every year at the Laboratory require a highly-skilled staff of scientists and technicians, and has given rise to a special organization called the "gun working group" to foster open communications, cooperation, problem-solving, and a healthy safety culture.

  7. The Los ALamos Neutron Science Center Hydrogen Moderator System

    NASA Astrophysics Data System (ADS)

    Jarmer, J. J.; Knudson, J. N.

    2006-04-01

    At the Los Alamos Neutron Science Center (LANSCE), spallation neutrons are produced by an 800-MeV proton beam interacting with tungsten targets. Gun-barrel-type penetrations through the heavy concrete and steel shielding that surround the targets collimate neutrons to form neutron beams used for scattering experiments. Two liquid hydrogen moderators of one-liter volume each are positioned adjacent to the neutron-production targets. Some of the neutrons that pass through a moderator interact with or scatter from protons in the hydrogen. The neutron-proton interaction reduces the energy or moderates neutrons to lower energies. Lower energy "moderated" neutrons are the most useful for some neutron scattering experiments. We provide a description of the LANSCE hydrogen-moderator system and its cryogenic performance with proton beams of up to 125 micro-amp average current.

  8. Los Alamos Guns Take Aim at Material's Mysteries

    ScienceCinema

    Byers, Mark; Moore, David; Dimarino, Steve

    2016-07-12

    Los Alamos National Laboratory scientists and technicians conduct thousands of experiments a year, delving into the fundamental nature of everything from supernovas to subatomic particles. One set of instruments used to better understand the fundamental nature of various materials are 10 scientific gun systems that fire various projectiles at high-tech targets to create enormous velocities, pressures, and temperatures - and using laser, x-ray, and other diagnostics - explore the very nature of metals and other materials. The hundreds of gun-based experiments conducted every year at the Laboratory require a highly-skilled staff of scientists and technicians, and has given rise to a special organization called the "gun working group" to foster open communications, cooperation, problem-solving, and a healthy safety culture.

  9. Los Alamos National Security, LLC Request for Information from industrial entities that desire to commercialize Laboratory-developed Extremely Low Resource Optical Identifier (ELROI) tech

    SciTech Connect

    Erickson, Michael Charles

    2015-11-10

    Los Alamos National Security, LLC (LANS) is the manager and operator of the Los Alamos National Laboratory for the U.S. Department of Energy National Nuclear Security Administration under contract DE-AC52-06NA25396. LANS is a mission-centric Federally Funded Research and Development Center focused on solving the most critical national security challenges through science and engineering for both government and private customers.

  10. The Los Alamos suite of relativistic atomic physics codes

    SciTech Connect

    Fontes, C. J.; Zhang, H. L.; Jr, J. Abdallah; Clark, R. E. H.; Kilcrease, D. P.; Colgan, J.; Cunningham, R. T.; Hakel, P.; Magee, N. H.; Sherrill, M. E.

    2015-05-28

    The Los Alamos SuitE of Relativistic (LASER) atomic physics codes is a robust, mature platform that has been used to model highly charged ions in a variety of ways. The suite includes capabilities for calculating data related to fundamental atomic structure, as well as the processes of photoexcitation, electron-impact excitation and ionization, photoionization and autoionization within a consistent framework. These data can be of a basic nature, such as cross sections and collision strengths, which are useful in making predictions that can be compared with experiments to test fundamental theories of highly charged ions, such as quantum electrodynamics. The suite can also be used to generate detailed models of energy levels and rate coefficients, and to apply them in the collisional-radiative modeling of plasmas over a wide range of conditions. Such modeling is useful, for example, in the interpretation of spectra generated by a variety of plasmas. In this work, we provide a brief overview of the capabilities within the Los Alamos relativistic suite along with some examples of its application to the modeling of highly charged ions.

  11. The Los Alamos suite of relativistic atomic physics codes

    DOE PAGES

    Fontes, C. J.; Zhang, H. L.; Jr, J. Abdallah; Clark, R. E. H.; Kilcrease, D. P.; Colgan, J.; Cunningham, R. T.; Hakel, P.; Magee, N. H.; Sherrill, M. E.

    2015-05-28

    The Los Alamos SuitE of Relativistic (LASER) atomic physics codes is a robust, mature platform that has been used to model highly charged ions in a variety of ways. The suite includes capabilities for calculating data related to fundamental atomic structure, as well as the processes of photoexcitation, electron-impact excitation and ionization, photoionization and autoionization within a consistent framework. These data can be of a basic nature, such as cross sections and collision strengths, which are useful in making predictions that can be compared with experiments to test fundamental theories of highly charged ions, such as quantum electrodynamics. The suitemore » can also be used to generate detailed models of energy levels and rate coefficients, and to apply them in the collisional-radiative modeling of plasmas over a wide range of conditions. Such modeling is useful, for example, in the interpretation of spectra generated by a variety of plasmas. In this work, we provide a brief overview of the capabilities within the Los Alamos relativistic suite along with some examples of its application to the modeling of highly charged ions.« less

  12. Los Alamos Center for Computer Security formal computer security model

    SciTech Connect

    Dreicer, J.S.; Hunteman, W.J.; Markin, J.T.

    1989-01-01

    This paper provides a brief presentation of the formal computer security model currently being developed at the Los Alamos Department of Energy (DOE) Center for Computer Security (CCS). The need to test and verify DOE computer security policy implementation first motivated this effort. The actual analytical model was a result of the integration of current research in computer security and previous modeling and research experiences. The model is being developed to define a generic view of the computer and network security domains, to provide a theoretical basis for the design of a security model, and to address the limitations of present formal mathematical models for computer security. The fundamental objective of computer security is to prevent the unauthorized and unaccountable access to a system. The inherent vulnerabilities of computer systems result in various threats from unauthorized access. The foundation of the Los Alamos DOE CCS model is a series of functionally dependent probability equations, relations, and expressions. The model is undergoing continued discrimination and evolution. We expect to apply the model to the discipline of the Bell and LaPadula abstract sets of objects and subjects. 6 refs.

  13. Seismic vulnerability study Los Alamos Meson Physics Facility (LAMPF)

    SciTech Connect

    Salmon, M.; Goen, L.K.

    1995-12-01

    The Los Alamos Meson Physics Facility (LAMPF), located at TA-53 of Los Alamos National Laboratory (LANL), features an 800 MeV proton accelerator used for nuclear physics and materials science research. As part of the implementation of DOE Order 5480.25 and in preparation for DOE Order 5480.28, a seismic vulnerability study of the structures, systems, and components (SSCs) supporting the beam line from the accelerator building through to the ends of die various beam stops at LAMPF has been performed. The study was accomplished using the SQUG GIP methodology to assess the capability of the various SSCs to resist an evaluation basis earthquake. The evaluation basis earthquake was selected from site specific seismic hazard studies. The goals for the study were as follows: (1) identify SSCs which are vulnerable to seismic loads; and (2) ensure that those SSCs screened during die evaluation met the performance goals required for DOE Order 5480.28. The first goal was obtained by applying the SQUG GIP methodology to those SSCS represented in the experience data base. For those SSCs not represented in the data base, information was gathered and a significant amount of engineering judgment applied to determine whether to screen the SSC or to classify it as an outlier. To assure the performance goals required by DOE Order 5480.28 are met, modifications to the SQUG GIP methodology proposed by Salmon and Kennedy were used. The results of this study ire presented in this paper.

  14. The reported views and experiences of cancer service users from minority ethnic groups: a critical review of the literature.

    PubMed

    Elkan, R; Avis, M; Cox, K; Wilson, E; Patel, S; Miller, S; Deepak, N; Edwards, C; Staniszewska, S; Kai, J

    2007-03-01

    There is growing evidence of inequalities in access to high-quality cancer services between minority and majority ethnic groups. However, little research has been carried out from the perspective of users from minority ethnic groups themselves. This paper reports a review of the British literature exploring the views and experiences of cancer service users from minority ethnic groups. We reviewed 25 qualitative studies that reported the experiences of people from minority ethnic groups. The studies highlighted significant issues and challenges, including comprehension and communication barriers, a lack of awareness of the existence of services and a perceived failure by providers to accommodate religious and cultural diversity. This paper critically discusses some of the explanations commonly invoked for ethnic inequalities in access to high-quality care, such as the belief that the lack of use of services reflects a lack of need. Despite positive initiatives to respond better to the needs of minority groups, we suggest the impact of these remains highly variable. Institutional racism within services is still much in evidence.

  15. Early social experience is critical for the development of cognitive control and dopamine modulation of prefrontal cortex function.

    PubMed

    Baarendse, Petra J J; Counotte, Danielle S; O'Donnell, Patricio; Vanderschuren, Louk J M J

    2013-07-01

    Social experiences during youth are thought to be critical for proper social and cognitive development. Conversely, social insults during development can cause long-lasting behavioral impairments and increase the vulnerability for psychopathology later in life. To investigate the importance of social experience during the juvenile and early adolescent stage for the development of cognitive control capacities, rats were socially isolated from postnatal day 21 to 42 followed by re-socialization until they reached adulthood. Subsequently, two behavioral dimensions of impulsivity (impulsive action in the five-choice serial reaction time task (5-CSRTT) and impulsive choice in the delayed reward task) and decision making (in the rat gambling task) were assessed. In a separate group of animals, long-lasting cellular and synaptic changes in adult medial prefrontal cortex (PFC) pyramidal neurons were determined following social isolation. Juvenile and early adolescent social isolation resulted in impairments in impulsive action and decision making under novel or challenging circumstances. Moreover, socially isolated rats had a reduced response to enhancement of dopaminergic neurotransmission (using amphetamine or GBR12909) in the 5-CSRTT under challenging conditions. Impulsive choice was not affected by social isolation. These behavioral deficits were accompanied by a loss of sensitivity to dopamine of pyramidal neurons in the medial PFC. Our data show long-lasting deleterious effects of early social isolation on cognitive control and its neural substrates. Alterations in prefrontal cognitive control mechanisms may contribute to the enhanced risk for psychiatric disorders induced by aberrations in the early social environment.

  16. Water Supply at Los Alamos during 1997

    SciTech Connect

    M. N. Maes; S. G. McLin; W. D. Purtymun

    1998-12-01

    Production of potable municipal water supplies during 1997 totaled about 1,285.9 million gallons from wells in the Guaje, Pajarito, and Otowi well fields. There was no water used from the spring gallery in Water Canyon or from Guaje Reservoir during 1997. About 2.4 million gallons of water from Los Alamos Reservoir was used to irrigate public parks and recreational lands. The total water usage in 1997 was about 1,288.3 million gallons, or about 135 gallons per day per person living in Los Alamos County. Groundwater pumpage was down about 82.2 million gallons in 1997 compared with the pumpage in 1996. Four new replacement wells were drilled and cased in Guaje Canyon between October 1997 and March 1998. These wells are currently being developed and aquifer tests are being performed. A special report summarizing the geological, geophysical, and well construction logs will be issued in the near future for these new wells.

  17. Los Alamos Team Demonstrates Bottle Scanner Technology

    ScienceCinema

    Espy, Michelle; Schultz, Larry

    2016-07-12

    Los Alamos scientists are demonstrating a Nuclear Magnetic Resonance Imaging (NMR) technology that may provide a breakthrough for screening liquids at airport security. By adding low-power X-ray data to the NMR mix, scientists believe they have unlocked a new detection technology. Funded in part by the Department of Homeland Security's Science and Technology Directorate, the new technology is called MagRay.

  18. Status of the Los Alamos Anger camera

    SciTech Connect

    Seeger, P.A.; Nutter, M.J.

    1985-01-01

    Results of preliminary tests of the neutron Anger camera being developed at Los Alamos are presented. This detector uses a unique encoding scheme involving parellel processing of multiple receptive fields. Design goals have not yet been met, but the results are very encouraging and improvements in the test procedures are expected to show that the detector will be ready for use on a small-angle scattering instrument next year. 3 refs., 4 figs.

  19. Los Alamos synchronous orbit data set

    SciTech Connect

    Baker, D.N.; Higbie, P.R.; Belian, R.D.; Hones, E.W.; Klebesadel, R.W.

    1981-01-01

    Energetic electron (30-15000 keV) and proton 145 keV to 150 MeV) measurements made by Los Alamos National Laboratory sensors at geostationary orbit (6.6 R/sub E/) are summarized. The instrumentation employed and the satellite positions are described. The spacecraft have been variously located, but in their present configuration the Los Alamos satellites designated 1976-059, 1977-007, and 1979-053 are located, respectively, at approx. 70/sup 0/W, approx. 70/sup 0/E, and approx. 135/sup 0/W longitude. Several examples of the high temporal and full three-dimensional spatial measurement capabilities of these instruments are illustrated by examples from the published literature. Discussion is also given for the Los Alamos Synoptic Data Set (SDS) which gives a broad overview of the Los Alamos geostationary orbit measurements. The SDS data are plotted in terms of daily average spectra, 3-hour local time averages, and in a variety of statistical formats. The data summarize conditions from mid-1976 through 1978 (S/C 1976-059) and from early 1977 through 1978 (S/C 1977-007). The SDS compilations presented correspond to measurements at 35/sup 0/W, 70/sup 0/W, and 135/sup 0/W geographic longitude and thus are indicative of conditions at 9/sup 0/, 11/sup 0/, and 4.8/sup 0/ geomagnetic latitude, respectively. The bulk of the SDS report presents data plots which are organized according to Carrington solar rotations and, as such, the data are readily comparable to solar rotation-dependent interplanetary conditions. Potential applications of the Synoptic Data Set (available to all interested users in June 1981) are discussed.

  20. Amphibians and Reptiles of Los Alamos County

    SciTech Connect

    Teralene S. Foxx; Timothy K. Haarmann; David C. Keller

    1999-10-01

    Recent studies have shown that amphibians and reptiles are good indicators of environmental health. They live in terrestrial and aquatic environments and are often the first animals to be affected by environmental change. This publication provides baseline information about amphibians and reptiles that are present on the Pajarito Plateau. Ten years of data collection and observations by researchers at Los Alamos National Laboratory, the University of New Mexico, the New Mexico Department of Game and Fish, and hobbyists are represented.

  1. Los Alamos Team Demonstrates Bottle Scanner Technology

    SciTech Connect

    Espy, Michelle; Schultz, Larry

    2014-05-06

    Los Alamos scientists are demonstrating a Nuclear Magnetic Resonance Imaging (NMR) technology that may provide a breakthrough for screening liquids at airport security. By adding low-power X-ray data to the NMR mix, scientists believe they have unlocked a new detection technology. Funded in part by the Department of Homeland Security's Science and Technology Directorate, the new technology is called MagRay.

  2. The Los Alamos accelerator code group

    SciTech Connect

    Krawczyk, F.L.; Billen, J.H.; Ryne, R.D.; Takeda, Harunori; Young, L.M.

    1995-05-01

    The Los Alamos Accelerator Code Group (LAACG) is a national resource for members of the accelerator community who use and/or develop software for the design and analysis of particle accelerators, beam transport systems, light sources, storage rings, and components of these systems. Below the authors describe the LAACG`s activities in high performance computing, maintenance and enhancement of POISSON/SUPERFISH and related codes and the dissemination of information on the INTERNET.

  3. Los Alamos Novel Rocket Design Flight Tested

    SciTech Connect

    Tappan, Bryce

    2014-10-23

    Los Alamos National Laboratory scientists recently flight tested a new rocket design that includes a high-energy fuel and a motor design that also delivers a high degree of safety. Researchers will now work to scale-up the design, as well as explore miniaturization of the system, in order to exploit all potential applications that would require high-energy, high-velocity, and correspondingly high safety margins.

  4. Los Alamos Novel Rocket Design Flight Tested

    ScienceCinema

    Tappan, Bryce

    2016-07-12

    Los Alamos National Laboratory scientists recently flight tested a new rocket design that includes a high-energy fuel and a motor design that also delivers a high degree of safety. Researchers will now work to scale-up the design, as well as explore miniaturization of the system, in order to exploit all potential applications that would require high-energy, high-velocity, and correspondingly high safety margins.

  5. Los Alamos National Laboratory Facility Review

    SciTech Connect

    Nelson, Ronald Owen

    2015-06-05

    This series of slides depicts the Los Alamos Neutron Science Center (LANSCE). The Center's 800-MeV linac produces H+ and H- beams as well as beams of moderated (cold to 1 MeV) and unmoderated (0.1 to 600 MeV) neutrons. Experimental facilities and their capabilities and characteristics are outlined. Among these are LENZ, SPIDER, and DANCE.

  6. Los Alamos National Laboratory building cost index

    SciTech Connect

    Orr, H.D.; Lemon, G.D.

    1982-10-01

    The Los Alamos National Laboratory Building Cost Index indicates that actual escalation since 1970 is near 10% per year. Therefore, the Laboratory will continue using a 10% per year escalation rate for construction estimates through 1985 and a slightly lower rate of 8% per year from 1986 through 1990. The computerized program compares the different elements involved in the cost of a typical construction project, which for our purposes, is a complex of office buildings and experimental laboratories. The input data used in the program consist primarily of labor costs and material and equipment costs. The labor costs are the contractual rates of the crafts workers in the Los Alamos area. For the analysis, 12 field-labor craft categories are used; each is weighted corresponding to the labor craft distribution associated with the typical construction project. The materials costs are current Los Alamos prices. Additional information sources include material and equipment quotes obtained through conversations with vendors and from trade publications. The material and equipment items separate into 17 categories for the analysis and are weighted corresponding to the material and equipment distribution associated with the typical construction project. The building cost index is compared to other national building cost indexes.

  7. Los Alamos National Laboratory Building Cost Index

    SciTech Connect

    Orr, H.D.; Lemon, G.D.

    1983-01-01

    The Los Alamos National Laboratory Building Cost Index indicates that actual escalation since 1970 is near 10% per year. Therefore, the Laboratory will continue using a 10% per year escalation rate for construction estimates through 1985 and a slightly lower rate of 8% per year from 1986 through 1990. The computerized program compares the different elements involved in the cost of a typical construction project, which for our purposes, is a complex of office buildings and experimental laboratores. The input data used in the program consist primarily of labor costs and material and equipment costs. The labor costs are the contractural rates of the crafts workers in the Los Alamos area. For the analysis, 12 field-labor draft categories are used; each is weighted corresponding to the labor craft distribution associated with the typical construction project. The materials costs are current Los Alamos prices. Additional information sources include material and equipment quotes obtained through conversations with vendors and from trade publications. The material and equipment items separate into 17 categories for the analysis and are weighted corresponding to the material and equipment distribution associated with the typical construction project. The building cost index is compared to other national building cost indexes.

  8. Final Environmental Impact Statement for the Proposed Relocation of Technical Area 18 Capabilities and Materials at the Los Alamos National Laboratory

    SciTech Connect

    N /A

    2002-09-20

    The National Nuclear Security Administration, a separately organized agency within DOE, is responsible for providing the Nation with nuclear weapons, ensuring the safety and reliability of those nuclear weapons, and supporting programs that reduce global nuclear proliferation. These missions are accomplished with a core team of highly trained nuclear experts. One of the major training facilities for these personnel is located at Technical Area 18 (TA-18), within the Los Alamos National Laboratory (LANL), Los Alamos, New Mexico. Principal TA-18 operational activities involve research in and the design, development, construction, and application of experiments on nuclear criticality. Though TA-18 is judged to be secure by DOE's independent inspection office, its buildings and infrastructure are from 30 to more than 50 years old and are increasingly expensive to maintain and operate. Additionally, the TA-18 operations are located in a relatively isolated area, resulting in increasingly high costs to maintain a security Category I infrastructure. NNSA wishes to maintain the important capabilities currently provided at TA-18 in a manner that reduces the long-term costs for safeguards and security. NNSA proposes to accomplish this by relocating the TA-18 security Category I/II capabilities and materials to new locations. The TA-18 Relocation EIS evaluates the potential direct, indirect, and cumulative environmental impacts associated with this proposed action at the following DOE sites: (1) a different site at LANL at Los Alamos, New Mexico; (2) the Sandia National Laboratories/New Mexico at Albuquerque, New Mexico; (3) the Nevada Test Site near Las Vegas, Nevada (the Preferred Alternative); and (4) the Argonne National Laboratory-West near Idaho Falls, Idaho. The EIS also analyzes the alternatives of upgrading the existing TA-18 facilities and the No Action Alternative of maintaining the operations at the current TA-18 location.

  9. Evaluation of the concrete shield compositions from the 2010 criticality accident alarm system benchmark experiments at the CEA Valduc SILENE facility

    SciTech Connect

    Miller, Thomas Martin; Celik, Cihangir; Dunn, Michael E; Wagner, John C; McMahan, Kimberly L; Authier, Nicolas; Jacquet, Xavier; Rousseau, Guillaume; Wolff, Herve; Savanier, Laurence; Baclet, Nathalie; Lee, Yi-kang; Trama, Jean-Christophe; Masse, Veronique; Gagnier, Emmanuel; Naury, Sylvie; Blanc-Tranchant, Patrick; Hunter, Richard; Kim, Soon; Dulik, George Michael; Reynolds, Kevin H.

    2015-01-01

    In October 2010, a series of benchmark experiments were conducted at the French Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA) Valduc SILENE facility. These experiments were a joint effort between the United States Department of Energy Nuclear Criticality Safety Program and the CEA. The purpose of these experiments was to create three benchmarks for the verification and validation of radiation transport codes and evaluated nuclear data used in the analysis of criticality accident alarm systems. This series of experiments consisted of three single-pulsed experiments with the SILENE reactor. For the first experiment, the reactor was bare (unshielded), whereas in the second and third experiments, it was shielded by lead and polyethylene, respectively. The polyethylene shield of the third experiment had a cadmium liner on its internal and external surfaces, which vertically was located near the fuel region of SILENE. During each experiment, several neutron activation foils and thermoluminescent dosimeters (TLDs) were placed around the reactor. Nearly half of the foils and TLDs had additional high-density magnetite concrete, high-density barite concrete, standard concrete, and/or BoroBond shields. CEA Saclay provided all the concrete, and the US Y-12 National Security Complex provided the BoroBond. Measurement data from the experiments were published at the 2011 International Conference on Nuclear Criticality (ICNC 2011) and the 2013 Nuclear Criticality Safety Division (NCSD 2013) topical meeting. Preliminary computational results for the first experiment were presented in the ICNC 2011 paper, which showed poor agreement between the computational results and the measured values of the foils shielded by concrete. Recently the hydrogen content, boron content, and density of these concrete shields were further investigated within the constraints of the previously available data. New computational results for the first experiment are now available that

  10. The Development, Content, Design, and Conduct of the 2011 Piloted US DOE Nuclear Criticality Safety Program Criticality Safety Engineering Training and Education Project

    SciTech Connect

    Hopper, Calvin Mitchell

    2011-01-01

    In May 1973 the University of New Mexico conducted the first nationwide criticality safety training and education week-long short course for nuclear criticality safety engineers. Subsequent to that course, the Los Alamos Critical Experiments Facility (LACEF) developed very successful 'hands-on' subcritical and critical training programs for operators, supervisors, and engineering staff. Since the inception of the US Department of Energy (DOE) Nuclear Criticality Technology and Safety Project (NCT&SP) in 1983, the DOE has stimulated contractor facilities and laboratories to collaborate in the furthering of nuclear criticality as a discipline. That effort included the education and training of nuclear criticality safety engineers (NCSEs). In 1985 a textbook was written that established a path toward formalizing education and training for NCSEs. Though the NCT&SP went through a brief hiatus from 1990 to 1992, other DOE-supported programs were evolving to the benefit of NCSE training and education. In 1993 the DOE established a Nuclear Criticality Safety Program (NCSP) and undertook a comprehensive development effort to expand the extant LACEF 'hands-on' course specifically for the education and training of NCSEs. That successful education and training was interrupted in 2006 for the closing of the LACEF and the accompanying movement of materials and critical experiment machines to the Nevada Test Site. Prior to that closing, the Lawrence Livermore National Laboratory (LLNL) was commissioned by the US DOE NCSP to establish an independent hands-on NCSE subcritical education and training course. The course provided an interim transition for the establishment of a reinvigorated and expanded two-week NCSE education and training program in 2011. The 2011 piloted two-week course was coordinated by the Oak Ridge National Laboratory (ORNL) and jointly conducted by the Los Alamos National Laboratory (LANL) classroom education and facility training, the Sandia National

  11. SNM holdup assessment of Los Alamos exhaust ducts. Final report

    SciTech Connect

    Marshall, R.S.

    1994-02-01

    Fissile material holdup in glovebox and fume hood exhaust ducting has been quantified for all Los Alamos duct systems. Gamma-based, nondestructive measurements were used to quantify holdup. The measurements were performed during three measurement campaigns. The first campaign, Phase I, provided foot-by-foot, semiquantitative measurement data on all ducting. These data were used to identify ducting that required more accurate (quantitative) measurement. Of the 280 duct systems receiving Phase I measurements, 262 indicated less than 50 g of fissile holdup and 19 indicated fissile holdup of 50 or more grams. Seven duct systems were measured in a second campaign, called Series 1, Phase II. Holdup estimates on these ducts ranged from 421 g of {sup 235}U in a duct servicing a shut-down uranium-machining facility to 39 g of {sup 239}Pu in a duct servicing an active plutonium-processing facility. Measurements performed in the second campaign proved excessively laborious, so a third campaign was initiated that used more efficient instrumentation at some sacrifice in measurement quality. Holdup estimates for the 12 duct systems measured during this third campaign ranged from 70 g of {sup 235}U in a duct servicing analytical laboratories to 1 g of {sup 235}U and 1 g of {sup 239}Pu in a duct carrying exhaust air to a remote filter building. These quantitative holdup estimates support the conclusion made at the completion of the Phase I measurements that only ducts servicing shut-down uranium operations contain about 400 g of fissile holdup. No ventilation ducts at Los Alamos contain sufficient fissile material holdup to present a criticality safety concern.

  12. Criticality Experiments with Mixed Plutonium and Uranium Nitrate Solution at a Plutonium Fraction of 0.4 in Slab and Cylindrical Geometry

    SciTech Connect

    Lloyd, RC

    1988-04-01

    A series of critical experiments was completed with mixed plutonium-uranium solutions having Pu/(Pu + U) ratios of approximately 0.4. These experiments were a part of the Criticality Data Development Program between the United States Department of Energy (USDOE), and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. A complete description of, and data from, the experiments are included in this report. The experiments were performed with mixed plutonium-uranium solutions in cylinqrical and slab geometries and included measurements with a water reflector, a concrete reflector, and without an added reflector. The concentration was varied from 105 to 436 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was 0.4 for all experiments.

  13. Criticality experiments with mixed plutonium and uranium nitrate solution at a plutonium fraction of 0.5 in slab and cylindrical geometry

    SciTech Connect

    Lloyd, R.C.

    1986-12-01

    A series of critical experiments was completed with mixed plutonium-uranium solutions having Pu/(Pu + U) ratios of approximately 0.5. These experiments were a part of the Criticality Data Development Program between the United States Department of Energy (USDOE), and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. A complete description of, and data from, the experiments are included in this report. The experiments were performed with mixed plutonium-uranium solutions in cylindrical and slab geometries and included measurements with a water reflector, a concrete reflector, and without an added reflector. The concentration was varied from 112 to 332 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was 52% for all experiments.

  14. Criticality Experiments with Mixed Plutonium and Uranium Nitrate Solution at a Plutonium Fraction of 0.5 in Annular Cylindrical Geometry

    SciTech Connect

    Lloyd, RC

    1988-04-01

    A series of critical experiments was completed with mixed plutonium-uranium solutions having Pu/(Pu + U) ratios of approximately 0.5. These experiments were a part of the Criticality Data Development Program between the United States Department of Energy (USDOE), and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. A complete description of, and data from, the experiments are included in this report. The experiments were performed with mixed plutonium-uranium solutions in annular cylindrical geometry. The measurements were made with a water reflector. The central region included a concrete annular cylinder containing B{sub 4}C. Interior to the concrete insert was a stainless steel bottle containing plutonium-uranium solution. The concentration of the solution in the annular region was varied from 116 to 433 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was 52% for all experiments.

  15. Decommissioning the UHTREX Reactor Facility at Los Alamos, New Mexico

    SciTech Connect

    Salazar, M.; Elder, J.

    1992-08-01

    The Ultra-High Temperature Reactor Experiment (UHTREX) facility was constructed in the late 1960s to advance high-temperature and gas-cooled reactor technology. The 3-MW reactor was graphite moderated and helium cooled and used 93% enriched uranium as its fuel. The reactor was run for approximately one year and was shut down in February 1970. The decommissioning of the facility involved removing the reactor and its associated components. This document details planning for the decommissioning operations which included characterizing the facility, estimating the costs of decommissioning, preparing environmental documentation, establishing a system to track costs and work progress, and preplanning to correct health and safety concerns in the facility. Work to decommission the facility began in 1988 and was completed in September 1990 at a cost of $2.9 million. The facility was released to Department of Energy for other uses in its Los Alamos program.

  16. Validation of the scale code system using criticality data from experiments performed with Pu + U solutions in cylindrical and slab geometry

    SciTech Connect

    Smolen, G.R.; Funabashi, H. )

    1988-01-01

    This paper outlines the results of a calculational study that was performed to validate two versions of the SCALE computer code system using data from critical experiments performed with mixed Pu + U aqueous solutions. The critical experiments were conducted in a 35-cm-diam cylinder and variable thickness slab tank. These experimental activities are part of a joint exchange program between the US Department of Energy (DOE) and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan in the area of criticality data development. The Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) manages the program for DOE. The experiments were conducted at the Battelle-Pacific Northwest Laboratories-Critical Mall Laboratory. Calculated multiplication factors have been examined for 36 critical experiments conducted in cylindrical and slab geometries with mixed Pu + U solutions. The results indicate that both the SCALE-2 and SCALE-4.0 computer code systems are capable of accurately modeling mixed fissile systems in simple geometry.

  17. Microstructure and Property Evolution in Advanced Cladding and Duct Materials Under Long-Term Irradiation at Elevated Temperature: Critical Experiments

    SciTech Connect

    Was, Gary; Jiao, Zhijie; Allen, Todd; Yang, Yong

    2013-12-20

    radiation on these important materials. The objective of this project is to conduct critical experiments to understand the evolution of microstructural and microchemical features (loops, voids, precipitates, and segregation) and mechanical properties (hardening and creep) under high temperature and full dose range radiation, including the effect of differences in the initial material composition and microstructure on the microstructural response, including key questions related to saturation of the microstructure at high doses and temperatures.

  18. Commercialization of Los Alamos National Laboratory technologies via small businesses. Final report

    SciTech Connect

    Brice, R.; Cartron, D.; Rhyne, T.; Schulze, M.; Welty, L.

    1997-06-01

    Over the past decade, numerous companies have been formed to commercialize research results from leading U.S. academic and research institutions. Emerging small businesses in areas such as Silicon Valley, Boston`s Route 128 corridor, and North Carolina`s Research Triangle have been especially effective in moving promising technologies from the laboratory bench to the commercial marketplace--creating new jobs and economic expansion in the process. Unfortunately, many of the U.S. national laboratories have not been major participants in this technology/commercialization activity, a result of a wide variety of factors which, until recently, acted against successful commercialization. This {open_quotes}commercialization gap{close_quotes} exists partly due to a lack, within Los Alamos in particular and the DOE in general, of in-depth expertise and experience in such business areas as new business development, securities regulation, market research and the determination of commercial potential, the identification of entrepreneurial management, marketing and distribution, and venture capital sources. The immediate consequence of these factors is the disappointingly small number of start-up companies based on technologies from Los Alamos National Laboratory that have been attempted, the modest financial return Los Alamos has received from these start-ups, and the lack of significant national recognition that Los Alamos has received for creating and commercializing these technologies.

  19. NEPA and NHPA- successful decommissioning of historic Manhattan Project properties at Los Alamos National Laboratory, Los Alamos, New Mexico

    SciTech Connect

    McGehee, E.D.; Pendergrass, A.K.

    1997-05-21

    This paper describes experiences at Los Alamos National Laboratory during the process of planning and executing decommissioning and decontamination activities on a number of properties constructed as part of the Manhattan project. Many of these buildings had been abandoned for many years and were in deteriorating condition, in addition to being contaminated with asbestos, lead based paints and high explosive residues. Due to the age and use of the structures they were evaluated against criteria for the National Register of Historic Places. This process is briefly reviewed, along with the results, as well as actions implemented as a result of the condition and safety of the structures. A number of the structures have been decontaminated and demolished. Planning is still ongoing for the renovation of one structure, and the photographic and drawing records of the properties is near completion.

  20. ORSPHERE: CRITICAL, BARE, HEU(93.2)-METAL SPHERE

    SciTech Connect

    Margaret A. Marshall

    2013-09-01

    In the early 1970’s Dr. John T. Mihalczo (team leader), J.J. Lynn, and J.R. Taylor performed experiments at the Oak Ridge Critical Experiments Facility (ORCEF) with highly enriched uranium (HEU) metal (called Oak Ridge Alloy or ORALLOY) in an attempt to recreate GODIVA I results with greater accuracy than those performed at Los Alamos National Laboratory in the 1950’s (HEU-MET-FAST-001). The purpose of the Oak Ridge ORALLOY Sphere (ORSphere) experiments was to estimate the unreflected and unmoderated critical mass of an idealized sphere of uranium metal corrected to a density, purity, and enrichment such that it could be compared with the GODIVA I experiments. “The very accurate description of this sphere, as assembled, establishes it as an ideal benchmark for calculational methods and cross-section data files.” (Reference 1) While performing the ORSphere experiments care was taken to accurately document component dimensions (±0. 0001 in. for non-spherical parts), masses (±0.01 g), and material data The experiment was also set up to minimize the amount of structural material in the sphere proximity. A three part sphere was initially assembled with an average radius of 3.4665 in. and was then machined down to an average radius of 3.4420 in. (3.4425 in. nominal). These two spherical configurations were evaluated and judged to be acceptable benchmark experiments; however, the two experiments are highly correlated.

  1. Los Alamos Before and After the Fire

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On May 4, 2000, a prescribed fire was set at Bandelier National Monument, New Mexico, to clear brush and dead and dying undergrowth to prevent a larger, subsequent wildfire. Unfortunately, due to high winds and extremely dry conditions in the surrounding area, the prescribed fire quickly raged out of control and, by May 10, the blaze had spread into the nearby town of Los Alamos. In all, more than 20,000 people were evacuated from their homes and more than 200 houses were destroyed as the flames consumed about 48,000 acres in and around the Los Alamos area. The pair of images above were acquired by the Enhanced Thematic Mapper Plus (ETM+) sensor, flying aboard NASA's Landsat 7 satellite, shortly before the Los Alamos fire (top image, acquired April 14) and shortly after the fire was extinguished (lower image, June 17). The images reveal the extent of the damage caused by the fire. Combining ETM+ channels 7, 4, and 2 (one visible and two infrared channels) results in a false-color image where vegetation appears as bright to dark green. Forested areas are generally dark green while herbaceous vegetation is light green. Rangeland or more open areas appear pink to light purple. Areas with extensive pavement or urban development appear light blue or white to purple. Less densely-developed residential areas appear light green and golf courses are very bright green. In the lower image, the areas recently burned appear bright red. Landsat 7 data courtesy United States Geological Survey EROS DataCenter. Images by Robert Simmon, NASA GSFC.

  2. Biological assessment for the effluent reduction program, Los Alamos National Laboratory, Los Alamos, New Mexico

    SciTech Connect

    Cross, S.P.

    1996-08-01

    This report describes the biological assessment for the effluent recution program proposed to occur within the boundaries of Los Alamos National Laboratory. Potential effects on wetland plants and on threatened and endangered species are discussed, along with a detailed description of the individual outfalls resulting from the effluent reduction program.

  3. LAMPF II workshop, Los Alamos National Laboratory, Los Alamos, New Mexico, February 1-4, 1982

    SciTech Connect

    Thiessen, H.A.

    1982-01-01

    This report contains the proceedings of the first LAMPF II Workshop held at Los Alamos February 1 to 4, 1982. Included are the talks that were available in written form. The conclusion of the participants was that there are many exciting areas of physics that will be addressed by such a machine.

  4. A Journey From Sandia To Los Alamos - 12465

    SciTech Connect

    Goyal, K.K.; Humphrey, B.J.; Krause, T.J.; Gluth, J.W.; Kiefer, M.L.; Haynes, S.

    2012-07-01

    The U.S. Department of Energy (DOE) relies on laboratory experiments and computer-based models to verify the reliability of the nation's nuclear stockpile. Sandia National Laboratories/New Mexico (SNL/NM) tests various materials in extreme environments designed to mimic those of nuclear explosions using the Z machine. The Z machine is a key tool in the National Nuclear Security Administration's (NNSA) stockpile stewardship mission and is used to study the dynamic properties of nuclear weapon materials. In 2006, SNL/NM and Los Alamos National Laboratory (LANL) signed a Memorandum of Understanding (MOU) defining experiments to be conducted in the Z machine involving plutonium (Pu) provided by LANL. Five Pu experiments have been completed with as many as 20 more planned through 2016. The experimental containment vessel used for the experiment and containing the Pu residues, becomes transuranic (TRU) waste after the experiment and termination of safeguards and is considered a LANL waste stream. Each containment vessel is placed in a 55-gallon Type A drum or standard waste box (SWB) for shipment back to LANL for final certification and eventual disposal at the Waste Isolation Pilot Plant (WIPP). The experimental containment vessels are greater than 99% metallic materials (ferrous and non-ferrous metals). In addition to the Pu targets, detonators with high explosives (HE) are used in the experiments to isolate the containment vessel from the Z machine as energy is delivered to the Pu samples. The characterization requirements, transportation issues, required documentation, and the approvals needed before shipments were challenging and required close coordination between SNL/NM, Sandia Site Office, LANL, Los Alamos Site Office, Washington TRU Solutions, Inc., the Central Characterization Project, and the Carlsbad Field Office. Between 2006 and 2010, representatives from SNL/NM and LANL worked to develop an approved path forward to meet the requirements of all stakeholders

  5. Materials accounting at Los Alamos National Laboratory

    SciTech Connect

    Roberts, N.J.; Erkkila, B.H.; Kelso, H.F.

    1985-07-20

    The materials accounting system at Los Alamos has evolved from an ''80-column'' card system to a very sophisticated near-real-time computerized nuclear material accountability and safeguards system (MASS). The present hardware was designed and acquired in the late 70's and is scheduled for a major upgrade in fiscal year 1986. The history of the system from 1950 through the DYMAC of the late 70's up to the present will be discussed. The philosophy of the system along with the details of the system will be covered. This system has addressed the integrated problems of management, control, and accounting of nuclear material successfully. 8 refs., 3 figs., 1 tab.

  6. Environmental Programs at Los Alamos National Laboratory

    SciTech Connect

    Jones, Patricia

    2012-07-11

    Summary of this project is: (1) Teamwork, partnering to meet goals - (a) Building on cleanup successes, (b) Solving legacy waste problems, (c) Protecting the area's environment; (2) Strong performance over the past three years - (a) Credibility from four successful Recovery Act Projects, (b) Met all Consent Order milestones, (c) Successful ramp-up of TRU program; (3) Partnership between the National Nuclear Security Administration's Los Alamos Site Office, DOE Carlsbad Field Office, New Mexico Environment Department, and contractor staff enables unprecedented cleanup progress; (4) Continued focus on protecting water resources; and (5) All consent order commitments delivered on time or ahead of schedule.

  7. Los Alamos National Laboratory computer benchmarking 1982

    SciTech Connect

    Martin, J.L.

    1983-06-01

    Evaluating the performance of computing machinery is a continual effort of the Computer Research and Applications Group of the Los Alamos National Laboratory. This report summarizes the results of the group's benchmarking activities performed between October 1981 and September 1982, presenting compilation and execution times as well as megaflop rates for a set of benchmark codes. Tests were performed on the following computers: Cray Research, Inc. (CRI) Cray-1S; Control Data Corporation (CDC) 7600, 6600, Cyber 73, Cyber 825, Cyber 835, Cyber 855, and Cyber 205; Digital Equipment Corporation (DEC) VAX 11/780 and VAX 11/782; and Apollo Computer, Inc., Apollo.

  8. Plant Uptake of Organic Pollutants from Soil: A Critical Review ofBioconcentration Estimates Based on Modelsand Experiments

    SciTech Connect

    McKone, Thomas E.; Maddalena, Randy L.

    2007-01-01

    The role of terrestrial vegetation in transferring chemicals from soil and air into specific plant tissues (stems, leaves, roots, etc.) is still not well characterized. We provide here a critical review of plant-to-soil bioconcentration ratio (BCR) estimates based on models and experimental data. This review includes the conceptual and theoretical formulations of the bioconcentration ratio, constructing and calibrating empirical and mathematical algorithms to describe this ratio and the experimental data used to quantify BCRs and calibrate the model performance. We first evaluate the theoretical basis for the BCR concept and BCR models and consider how lack of knowledge and data limits reliability and consistency of BCR estimates. We next consider alternate modeling strategies for BCR. A key focus of this evaluation is the relative contributions to overall uncertainty from model uncertainty versus variability in the experimental data used to develop and test the models. As a case study, we consider a single chemical, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and focus on variability of bioconcentration measurements obtained from 81 experiments with different plant species, different plant tissues, different experimental conditions, and different methods for reporting concentrations in the soil and plant tissues. We use these observations to evaluate both the magnitude of experimental variability in plant bioconcentration and compare this to model uncertainty. Among these 81 measurements, the variation of the plant/soil BCR has a geometric standard deviation (GSD) of 3.5 and a coefficient of variability (CV-ratio of arithmetic standard deviation to mean) of 1.7. These variations are significant but low relative to model uncertainties--which have an estimated GSD of 10 with a corresponding CV of 14.

  9. Analysis of muon radiography of the Toshiba nuclear critical assembly reactor

    SciTech Connect

    Morris, C. L.; Bacon, Jeffery; Borozdin, Konstantin; Fabritius, J. M.; Perry, John; Ramsey, John; Ban, Yuichiro; Izumi, Mikio; Sano, Yuji; Yoshida, Noriyuki; Miyadera, Haruo; Mizokami, Shinya; Otsuka, Yasuyuki; Yamada, Daichi; Sugita, Tsukasa; Yoshioka, Kenichi

    2014-01-13

    A 1.2 × 1.2 m{sup 2} muon tracker was moved from Los Alamos to the Toshiba facility at Kawasaki, Japan, where it was used to take ∼4 weeks of data radiographing the Toshiba Critical Assembly Reactor with cosmic ray muons. In this paper, we describe the analysis procedure, show results of this experiment, and compare the results to Monte Carlo predictions. The results validate the concept of using cosmic rays to image the damaged cores of the Fukushima Daiichi reactors.

  10. Critical experiments with 4. 31 wt % /sup 235/U-enriched UO/sub 2/ rods in highly borated water lattices

    SciTech Connect

    Durst, B.M.; Bierman, S.R.; Clayton, E.D.

    1982-08-01

    A series of critical experiments were performed with 4.31 wt % /sup 235/U enriched UO/sub 2/ fuel rods immersed in water containing various concentrations of boron ranging up to 2.55 g/l. The boron was added in the form of boric acid (H/sub 3/BO/sub 3/). Critical experimental data were obtained for two different lattice pitches wherein the water-to-uranium oxide volume ratios were 1.59 and 1.09. The experiments provide benchmarks on heavily borated systems for use in validating calculational techniques employed in analyzing fuel shipping casks and spent fuel storage systems that may utilize boron for criticality control.

  11. Experiments on small-size fast critical fuel assemblies at the AKSAMIT facility and their use for development of computational models

    NASA Astrophysics Data System (ADS)

    Glushkov, E. S.; Glushkov, A. E.; Gomin, E. A.; Daneliya, S. B.; Zimin, A. A.; Kalugin, M. A.; Kapitonova, A. V.; Kompaniets, G. V.; Moroz, N. P.; Nosov, V. I.; Petrushenko, R. P.; Smirnov, O. N.

    2013-12-01

    Small-size fast critical assemblies with highly enriched fuel at the AKSAMIT facility are described in detail. Computational models of the critical assemblies at room temperature are given. The calculation results for the critical parameters are compared with the experimental data. A good agreement between the calculations and the experimental data is shown. The physical models developed for the critical assemblies, as well as the experimental results, can be applied to verify various codes intended for calculation of the neutronic characteristics of small-size fast nuclear reactors. For these experiments, the results computed using the codes of the MCU family show a high quality of the neutron data and of the physical models used.

  12. Nuclear criticality safety experiments, calculations, and analyses - 1958 to 1982. Volume 2. Summaries. Complilation of papers from the Transactions of the American Nuclear Society

    SciTech Connect

    Koponen, B.L.; Hampel, V.E.

    1982-10-21

    This compilation contains 688 complete summaries of papers on nuclear criticality safety as presented at meetings of the American Nuclear Society (ANS). The selected papers contain criticality parameters for fissile materials derived from experiments and calculations, as well as criticality safety analyses for fissile material processing, transport, and storage. The compilation was developed as a component of the Nuclear Criticality Information System (NCIS) now under development at the Lawrence Livermore National Laboratory. The compilation is presented in two volumes: Volume 1 contains a directory to the ANS Transaction volume and page number where each summary was originally published, the author concordance, and the subject concordance derived from the keyphrases in titles. Volume 2 contains-in chronological order-the full-text summaries, reproduced here by permission of the American Nuclear Society from their Transactions, volumes 1-41.

  13. Guided by Great Feelings of Love: Using Photovoice and Critical Pedagogy to Document the Life Experiences of Undocumented Latino/a Students in Higher Education

    ERIC Educational Resources Information Center

    Ortega, Ricardo Elias

    2013-01-01

    Undocumented students have fought for the ability to attend institutions of higher education, but research has often overlooked their experiences outside of the classroom. Weaving together Freirean critical pedagogy and photovoice to create a type of advocacy participatory action research, this project followed eight undocumented Latina/o…

  14. Writing Critical Race Theory and Method: A Composite Counterstory on the Experiences of Black Teachers in New Orleans Post-Katrina

    ERIC Educational Resources Information Center

    Cook, Daniella Ann; Dixson, Adrienne D.

    2013-01-01

    Using a critical race theory lens, the authors propose a way of writing race research using composite counterstories. Drawing on data from a yearlong study of school rebuilding in the time period immediately after Hurricane Katrina devastated the City of New Orleans, the authors examine the experiences of African-American educators in the school…

  15. Towards a conceptual model of motorcyclists' Risk Awareness: a comparative study of riding experience effect on hazard detection and situational criticality assessment.

    PubMed

    Bellet, Thierry; Banet, Aurélie

    2012-11-01

    This research investigates risk awareness abilities among different populations of motorcyclists. Risk awareness is defined here as an extension of the Situational Awareness theory applied to critical driving situations. This study is more particularly focused on two main cognitive abilities supporting risk awareness: hazard detection, corresponding to riders' skill to perceive critical event occurring in the road environment and to identify it as a threat, and situational criticality assessment, corresponding to a subjective assessment of the accident risk. From this theoretical framework, the aim is to compare motorcyclists' performances in risk awareness according to their experience in motorcycling. Four populations of motorcyclists are investigated: Professional (Policemen), Experienced riders, Novices, and Beginners. Method implemented is based of a set of 25 video sequences of driving situations presenting a risk of collision. Participants' task was firstly to stop the video film if they detect a hazard. Then, at the end of each sequence, they have also to assess the criticality of the driving situation as a whole, with a Likert scale (from 0 to 100% of criticality). Results obtained show that cognitive abilities in both (i) hazard detection and (ii) situational criticality assessment depend of the riding experience, and are learnt from two different timing. On one side, Professional and Experienced riders obtained better results than Novices and Beginners for hazard perception (i.e. shortest reaction time). In terms of situational criticality assessment, Beginners underestimate the situational risk and seem overconfident in their abilities to manage the situational risk, against Novices, Professional and Experienced riders, who have better competences in criticality assessment. From these empirical results, a conceptual model of motorcyclists' Risk Awareness is proposed.

  16. Automatic beam position control at Los Alamos Spallation Radiation Effects Facility (LASREF)

    SciTech Connect

    Oothoudt, M.; Pillai, C.; Zumbro, M.

    1997-08-01

    Historically the Los Alamos Spallation Radiation Effects Facility (LASREF) has used manual methods to control the position of the 800 kW, 800 MeV proton beam on targets. New experiments, however, require more stringent position control more frequently than can be done manually for long periods of time. Data from an existing harp is used to automatically adjust steering magnets to maintain beam position to required tolerances.

  17. The Climate at Los Alamos; Are we measurement changes?

    SciTech Connect

    Dewart, Jean Marie

    2015-04-16

    A new report shows new graphic displays of the weather trends in Los Alamos, New Mexico, and at the Los Alamos National Laboratory (LANL). The graphs show trends of average, minimum average, and maximum average temperature for summer and winter months going back decades. Records of summer and winter precipitation are also included in the report.

  18. Radionuclide concentrations in pinto beans, sweet corn, and zucchini squash grown in Los Alamos Canyon at Los Alamos National Laboratory

    SciTech Connect

    Fresquez, P.R.; Mullen, M.A.; Naranjo, L. Jr.; Armstrong, D.R.

    1997-05-01

    Pinto beans, sweet corn, and zucchini squash (Cucurbita pepo var. black beauty) were grown in a randomized complete-block field/pot experiment at a site that contained the highest observed levels of surface gross gamma radioactivity within Los Alamos Canyon (LAC) at Los Alamos National Laboratory. Soils as well as washed edible and nonedible crop tissues were analyzed for various radionuclides and heavy metals . Most radionuclides, with the exception of {sup 3}H and {sup tot}U, in soil from LAC were detected in significantly higher concentrations (p <0.01) than in soil collected from regional background (RBG) locations. Similarly, most radionuclides in edible crop portions of beans, squash, and corn were detected in significantly higher (p <0.01 and 0.05) concentrations than RBG. Most soil-to-plant concentration ratios for radionuclides in edible and nonedible crop tissues from LAC were within the default values given by the Nuclear Regulatory Commission and Environmental Protection Agency. All heavy metals in soils, as well as edible and nonedible crop tissues grown in soils from LAC, were within RBG concentrations. Overall, the total maximum net positive committed effective dose equivalent (CEDE)--the CEDE plus two sigma for each radioisotope minus background and then all positive doses summed--to a hypothetical 50-year resident that ingested 160 kg of beans, corn, and squash in equal proportions, was 74 mrem y{sup -1}. This dose was below the International Commission on Radiological Protection permissible dose limit (PDL) of 100 mrem y{sup -1} from all pathways; however, the addition of other internal and external exposure route factors may increase the overall dose over the PDL. Also, the risk of an excess cancer fatality, based on 74 mrem y{sup -1}, was 3.7 x 10{sup -5} (37 in a million), which is above the Environmental Protection Agency`s (acceptable) guideline of one in a million. 31 refs., 15 tabs.

  19. Criticality Model

    SciTech Connect

    A. Alsaed

    2004-09-14

    The ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003) presents the methodology for evaluating potential criticality situations in the monitored geologic repository. As stated in the referenced Topical Report, the detailed methodology for performing the disposal criticality analyses will be documented in model reports. Many of the models developed in support of the Topical Report differ from the definition of models as given in the Office of Civilian Radioactive Waste Management procedure AP-SIII.10Q, ''Models'', in that they are procedural, rather than mathematical. These model reports document the detailed methodology necessary to implement the approach presented in the Disposal Criticality Analysis Methodology Topical Report and provide calculations utilizing the methodology. Thus, the governing procedure for this type of report is AP-3.12Q, ''Design Calculations and Analyses''. The ''Criticality Model'' is of this latter type, providing a process evaluating the criticality potential of in-package and external configurations. The purpose of this analysis is to layout the process for calculating the criticality potential for various in-package and external configurations and to calculate lower-bound tolerance limit (LBTL) values and determine range of applicability (ROA) parameters. The LBTL calculations and the ROA determinations are performed using selected benchmark experiments that are applicable to various waste forms and various in-package and external configurations. The waste forms considered in this calculation are pressurized water reactor (PWR), boiling water reactor (BWR), Fast Flux Test Facility (FFTF), Training Research Isotope General Atomic (TRIGA), Enrico Fermi, Shippingport pressurized water reactor, Shippingport light water breeder reactor (LWBR), N-Reactor, Melt and Dilute, and Fort Saint Vrain Reactor spent nuclear fuel (SNF). The scope of this analysis is to document the criticality computational method. The criticality

  20. Teaching effectiveness and learning outcomes of baccalaureate nursing students in a critical care practicum: a lebanese experience.

    PubMed

    Makarem, S; Dumit, N Y; Adra, M; Kassak, K

    2001-01-01

    This process-product replicated study examines the relationship between the clinical teacher behavior effectiveness of critical care instructors and baccalaureate nursing students' learning outcomes in a critical care practicum. Teacher behaviors that were found to be significantly associated with student learning outcomes included flexibility, giving opportunity to observe, quality of answering questions, quality of discourse, feedback specificity, and concern for the learner's progress and problems.

  1. The large area crop inventory experiment: An experiment to demonstrate how space-age technology can contribute to solving critical problems here on earth

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The large area crop inventory experiment is being developed to predict crop production through satellite photographs. This experiment demonstrates how space age technology can contribute to solving practical problems of agriculture management.

  2. Portable MRI developed at Los Alamos

    SciTech Connect

    Espy, Michelle

    2015-04-22

    Scientists at Los Alamos National Laboratory are developing an ultra-low-field Magnetic Resonance Imaging (MRI) system that could be low-power and lightweight enough for forward deployment on the battlefield and to field hospitals in the World's poorest regions. "MRI technology is a powerful medical diagnostic tool," said Michelle Espy, the Battlefield MRI (bMRI) project leader, "ideally suited for imaging soft-tissue injury, particularly to the brain." But hospital-based MRI devices are big and expensive, and require considerable infrastructure, such as large quantities of cryogens like liquid nitrogen and helium, and they typically use a large amount of energy. "Standard MRI machines just can't go everywhere," said Espy. "Soldiers wounded in battle usually have to be flown to a large hospital and people in emerging nations just don't have access to MRI at all. We've been in contact with doctors who routinely work in the Third World and report that MRI would be extremely valuable in treating pediatric encephalopathy, and other serious diseases in children." So the Los Alamos team started thinking about a way to make an MRI device that could be relatively easy to transport, set up, and use in an unconventional setting. Conventional MRI machines use very large magnetic fields that align the protons in water molecules to then create magnetic resonance signals, which are detected by the machine and turned into images. The large magnetic fields create exceptionally detailed images, but they are difficult and expensive to make. Espy and her team wanted to see if images of sufficient quality could be made with ultra-low-magnetic fields, similar in strength to the Earth's magnetic field. To achieve images at such low fields they use exquisitely sensitive detectors called Superconducting Quantum Interference Devices, or SQUIDs. SQUIDs are among the most sensitive magnetic field detectors available, so interference with the signal is the primary stumbling block. "SQUIDs are

  3. Los Alamos experiments on the few nucleon systems

    SciTech Connect

    Spinka, H.

    1986-01-01

    A summary of recently studied proton-, pion-, and neutron-induced reactions on nuclei up to /sup 4/He at LAMPF is given. Upgrades to the LAMPF experimental facilities for these studies are described. Some new proton-proton total cross sections in pure helicity states (..delta..sigma/sub L/(pp)) from the ZGS near 3 GeV/c are also presented. 46 refs., 4 figs.

  4. Environmental surveillance at Los Alamos during 1987

    SciTech Connect

    Not Available

    1988-05-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1987. Routine monitoring for radiation and radioactive or chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of potentially undesirable trends. Results and interpretation of data for 1987 cover: external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels provide the basis for concluding that environmental effects from Laboratory operations are insignificant and do not pose a threat to the public, Laboratory employees, or the environment. 113 refs., 33 figs., 120 tabs.

  5. Environmental surveillance at Los Alamos during 1995

    SciTech Connect

    1996-10-01

    This report describes the environmental surveillance program at Los Alamos National Laboratory (LANL or the Laboratory) during 1995. The Laboratory routinely monitors for radiation and for radioactive and nonradioactive materials at (or on) Laboratory sites as well as in the surrounding region. LANL uses the monitoring result to determine compliance with appropriate standards and to identify potentially undesirable trends. Data were collected in 1995 to assess external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Using comparisons with standards, regulations, and background levels, this report concludes that environmental effects from Laboratory operations are small and do not pose a demonstrable threat to the public, Laboratory employees, or the environment.

  6. Environmental surveillance at Los Alamos during 1979

    SciTech Connect

    Not Available

    1980-04-01

    This report documents the environmental surveillance program conducted by the Los Alamos Scientific Laboratory (LASL) in 1979. Routine monitoring for radiation and radioactive or chemical substances was conducted on the Laboratory site and in the surrounding region to determine compliance with appropriate standards and permit early identification of possible undesirable trends. Results and interpretation of the data for 1979 on penetrating radiation, chemical and radiochemical quality of ambient air, surface and ground water, municipal water supply, soils and sediments, food, and airborne and liquid effluents are included. Comparisons with appropriate standards and regulations or with background levels from natural or other non-LASL sources provide a basis for concluding that environmental effects attributable to LASL operations are minor and cannot be considered likely to result in any hazard to the population of the area. Results of several special studies provide documentation of some unique environmental conditions in the LASL environs.

  7. Environmental surveillance at Los Alamos during 1989

    SciTech Connect

    Not Available

    1990-12-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1989. Routine monitoring for radiation and radioactive or chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of potentially undesirable trends. Results and interpretation of data for 1989 cover external penetrating radiation; quantities of airborne emissions and effluents; concentrations of chemicals and radionuclides in ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels provide the basis for concluding that environmental effects from Laboratory operations are small and do not pose a threat to the public, Laboratory employees, or the environment. 58 refs., 31 figs., 39 tabs.

  8. Environmental surveillance at Los Alamos during 1992

    SciTech Connect

    Kohen, K.; Stoker, A.; Stone, G.

    1994-07-01

    This report describes the environmental surveillance program at Los Alamos National Laboratory during 1992. The Laboratory routinely monitors for radiation and for radioactive and nonradioactive materials at (or on) Laboratory sites as well as in the surrounding region. LANL uses the monitoring results to determine compliance with appropriate standards and to identify potentially undesirable trends. Data were collected in 1992 to assess external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Using comparisons with standards, regulations, and background levels, this report concludes that environmental effects from Laboratory operations are small and do not pose a demonstrable threat to the public, laboratory employees, or the environment.

  9. The Los Alamos Intense Neutron Source

    SciTech Connect

    Nebel, R.A.; Barnes, D.C.; Bollman, R.; Eden, G.; Morrison, L.; Pickrell, M.M.; Reass, W.

    1997-10-01

    The Intense Neutron Source (INS) is an Inertial Electrostatic Confinement (IEC) fusion device presently under construction at Los Alamos National Laboratory. It is designed to produce 10{sup 11} neutrons per second steady-state using D-T fuel. Phase 1 operation of this device will be as a standard three grid IEC ion focus device. Expected performance has been predicted by scaling from a previous IEC device. Phase 2 operation of this device will utilize a new operating scheme, the Periodically Oscillating Plasma Sphere (POPS). This scheme is related to both the Spherical Reflect Diode and the Oscillating Penning Trap. With this type of operation the authors hope to improve plasma neutron production to about 10{sup 13} neutrons/second.

  10. Criticality Experiments with Mixed Plutonium and Uranium Nitrate Solution at a Plutonium Fraction of 0.2 and 1.0 in Annular Cylindrical Geometry

    SciTech Connect

    Lloyd, RC

    1988-04-01

    A series of critical experiments was completed with mixed plutoniumuranium solutions having Pu/(Pu + U) ratios of approximately 0.2 and 1.0. These experiments were a part of the Criticality Data Development Program between the United States Department of Energy (USDOE), and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. A complete description of, and data from, the experiments are included in this report. The experiments were performed with mixed plutonium-uranium solutions in annular cylindrical geometry. The measurements were made with a water reflector. The central region included a concrete, polyethylene or void annular cylindrical insert. Interior to the insert was a stainless steel bottle containing plutonium-uranium solution or a void region. In one experiment the central region was filled with a solid cadmium-covered polyethylene insert. The concentration of the solution in the annular region was varied from 61 to 489 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was 0.22 or 0.97 for all experiments.

  11. Explorer at Los Alamos: A library for the future

    SciTech Connect

    Waters, M.; McDonald, J.

    1998-03-01

    Since 1993, Los Alamos National Laboratory, has been developing World Wide Web (WWW) applications to facilitate access to vast quantities of information critical to the successful operation of a nuclear weapons facility Explorer is a web-based tool that integrates full-text search and retrieval technology, custom user in interface faces, user-friendly navigation tools, extremely large document collections, and data collection and workflow applications. Explorer`s first major thrust was to enable quick access to regulatory and policy information used by Department of Energy facilities throughout the country. Today, Explorer users can easily search document collections containing, millions of pages of information scattered across Web sites around the country. Over fifteen large applications containing multiple collections are searchable through Explorer, and the subject areas range from DOE regulations to quality management-related resources to technology transfer opportunities. Explorer has succeeded because it provides quick and easy access to stored data across the Web; it saves time and reduces costs in comparison with traditional information distribution, access, and retrieval methods.

  12. Environmental analysis of Lower Pueblo/Lower Los Alamos Canyon, Los Alamos, New Mexico

    SciTech Connect

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Becker, N.M.; Rodgers, J.C.; Hansen, W.R.

    1994-12-01

    The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, Pueblo Canyon, and Los Alamos Canyon found residual contamination at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons all the way to the Rio Grande. The largest reservoir of residual radioactivity is in lower Pueblo Canyon, which is on DOE property. However, residual radioactivity does not exceed proposed cleanup criteria in either lower Pueblo or lower Los Alamos Canyons. The three alternatives proposed are (1) to take no action, (2) to construct a sediment trap in lower Pueblo Canyon to prevent further transport of residual radioactivity onto San Ildefonso Indian Pueblo land, and (3) to clean the residual radioactivity from the canyon system. Alternative 2, to cleanup the canyon system, is rejected as a viable alternative. Thousands of truckloads of sediment would have to be removed and disposed of, and this effort is unwarranted by the low levels of contamination present. Residual radioactivity levels, under either present conditions or projected future conditions, will not result in significant radiation doses to persons exposed. Modeling efforts show that future transport activity will not result in any residual radioactivity concentrations higher than those already existing. Thus, although construction of a sediment trap in lower Pueblo Canyon is a viable alternative, this effort also is unwarranted, and the no-action alternative is the preferred alternative.

  13. Environmental surveillance at Los Alamos during 2009

    SciTech Connect

    Fuehne, David; Poff, Ben; Hjeresen, Denny; Isaacson, John; Johnson, Scot; Morgan, Terry; Paulson, David; Salzman, Sonja; Rogers, David

    2010-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (the Laboratory) environmental organization, as required by US Department of Energy Order 5400.1, General Environmental Protection Program, and US Department of Energy Order 231.1A, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory’s efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory’s major environmental programs and explains the risks and the actions taken to reduce risks at the Laboratory from environmental legacies and waste management operations. Chapter 2 reports the Laboratory’s compliance status for 2009. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations and discusses chemical exposures. The environmental surveillance and monitoring data are organized by environmental media (air in Chapter 4; water and sediments in Chapters 5 and 6; soils in Chapter 7; and foodstuffs and biota in Chapter 8) in a format to meet the needs of a general and scientific audience. Chapter 9 provides a summary of the status of environmental restoration work around LANL. The new Chapter 10 describes the Laboratory’s environmental stewardship efforts and provides an overview of the health of the Rio Grande. A glossary and a list of acronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the Laboratory’s technical

  14. Environmental surveillance at Los Alamos during 2008

    SciTech Connect

    Fuehne, David; Gallagher, Pat; Hjeresen, Denny; Isaacson, John; Johson, Scot; Morgan, Terry; Paulson, David; Rogers, David

    2009-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (the Laboratory) Environmental Programs Directorate, as required by US Department of Energy Order 450.1, General Environmental Protection Program, and US Department of Energy Order 231.1A, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory’s efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory’s major environmental programs and explains the risks and the actions taken to reduce risks at the Laboratory from environmental legacies and waste management operations. Chapter 2 reports the Laboratory’s compliance status for 2007. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations and discusses chemical exposures. The environmental surveillance and monitoring data are organized by environmental media (Chapter 4, air; Chapters 5 and 6, water and sediments; Chapter 7, soils; and Chapter 8, foodstuffs and biota) in a format to meet the needs of a general and scientific audience. Chapter 9 provides a summary of the status of environmental restoration work around LANL. A glossary and a list of acronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the Laboratory’s technical areas and their associated programs, and Appendix D provides web links to more information.

  15. Environmental surveillance at Los Alamos during 2005

    SciTech Connect

    2006-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (LANL or the Laboratory) environmental organization, as required by US Department of Energy Order 5400.1, General Environmental Protection Program, and US Department of Energy Order 231.IA, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory's efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory's major environmental programs. Chapter 2 reports the Laboratory's compliance status for 2005. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations. The environmental surveillance and monitoring data are organized by environmental media (Chapter 4, Air; Chapters 5 and 6, Water and Sediments; Chapter 7, Soils; and Chapter 8, Foodstuffs and Biota) in a format to meet the needs of a general and scientific audience. Chapter 9, new for this year, provides a summary of the status of environmental restoration work around LANL. A glossary and a list ofacronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the Laboratory's technical areas and their associated programs, and Appendix D provides web links to more information.

  16. Integrating Safety with Science,Technology and Innovation at Los Alamos National Laboratory

    SciTech Connect

    Rich, Bethany M

    2012-04-02

    The mission of Los Alamos National Laboratory (LANL) is to develop and apply science, technology and engineering solutions to ensure the safety, security, and reliability of the U.S. nuclear deterrent; reduce global threats; and solve emerging national security challenges. The most important responsibility is to direct and conduct efforts to meet the mission with an emphasis on safety, security, and quality. In this article, LANL Environmental, Safety, and Health (ESH) trainers discuss how their application and use of a kinetic learning module (learn by doing) with a unique fall arrest system is helping to address one the most common industrial safety challenges: slips and falls. A unique integration of Human Performance Improvement (HPI), Behavior Based Safety (BBS) and elements of the Voluntary Protection Program (VPP) combined with an interactive simulator experience is being used to address slip and fall events at Los Alamos.

  17. Final Progress Report: Internship at Los Alamos National Laboratory

    SciTech Connect

    Dunham, Ryan Q.

    2012-08-10

    Originally I was tasked fluidized bed modeling, however, I changed projects. While still working with ANSYS Fluent, I performed a study of particle tracks in glove boxes. This is useful from a Health-Physics perspective, dealing respirable particles that can be hazardous to the human body. I iteratively tested different amounts of turbulent particles in a steady-state flow. The goal of this testing was to discover how Fluent handles built-in Rosin-Rammler distributions for particle injections. I worked on the health physics flow problems and distribution analysis under the direction of two mentors, Bruce Letellier and Dave Decroix. I set up and ran particle injection calculations using Fluent. I tried different combinations of input parameters to produce sets of 500,000, 1 million, and 1.5 million particles to determine what a good test case would be for future experiments. I performed a variety of tasks in my work as an Undergraduate Student Intern at LANL this summer, and learned how to use a powerful CFD application in addition to expanding my skills in MATLAB. I enjoyed my work at LANL and hope to be able to use the experience here to further my career in the future working in a security-conscious environment. My mentors provided guidance and help with all of my projects and I am grateful for the opportunity to work at Los Alamos National Laboratory.

  18. Quantum critical scaling at a Bose-glass/superfluid transition: Theory and experiment for a model quantum magnet

    NASA Astrophysics Data System (ADS)

    Yu, Rong; Miclea, Corneliu F.; Weickert, Franziska; Movshovich, Roman; Paduan-Filho, Armando; Zapf, Vivien S.; Roscilde, Tommaso

    2012-10-01

    In this paper we investigate the quantum phase transition from magnetic Bose Glass to magnetic Bose-Einstein condensation induced by a magnetic field in NiCl2·4SC(NH2)2 (dichloro-tetrakis-thiourea-nickel, or DTN), doped with Br (Br-DTN) or site diluted. Quantum Monte Carlo simulations for the quantum phase transition of the model Hamiltonian for Br-DTN, as well as for site-diluted DTN, are consistent with conventional scaling at the quantum critical point and with a critical exponent z verifying the prediction z=d; moreover the correlation length exponent is found to be ν=0.75(10), and the order parameter exponent to be β=0.95(10). We investigate the low-temperature thermodynamics at the quantum critical field of Br-DTN both numerically and experimentally, and extract the power-law behavior of the magnetization and of the specific heat. Our results for the exponents of the power laws, as well as previous results for the scaling of the critical temperature to magnetic ordering with the applied field, are incompatible with the conventional crossover-scaling Ansatz proposed by Fisher [Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.40.546 40, 546 (1989)]. However they can all be reconciled within a phenomenological Ansatz in the presence of a dangerously irrelevant operator.

  19. Students' Critical Mathematical Thinking Skills and Character: Experiments for Junior High School Students through Realistic Mathematics Education Culture-Based

    ERIC Educational Resources Information Center

    Palinussa, Anderson L.

    2013-01-01

    This paper presents the findings of a quasi-experimental with pre-test-post-test design and control group that aims to assess students' critical mathematical thinking skills and character through realistic mathematics education (RME) culture-based. Subjects of this study were 106 junior high school students from two low and medium schools level in…

  20. Assessment of the available {sup 233}U cross-section evaluations in the calculation of critical benchmark experiments

    SciTech Connect

    Leal, L.C.; Wright, R.Q.

    1996-10-01

    In this report we investigate the adequacy of the available {sup 233}U cross-section data for calculation of experimental critical systems. The {sup 233}U evaluations provided in two evaluated nuclear data libraries, the U.S. Data Bank [ENDF/B (Evaluated Nuclear Data Files)] and the Japanese Data Bank [JENDL (Japanese Evaluated Nuclear Data Library)] are examined. Calculations were performed for six thermal and ten fast experimental critical systems using the S{sub n} transport XSDRNPM code. To verify the performance of the {sup 233}U cross-section data for nuclear criticality safety application in which the neutron energy spectrum is predominantly in the epithermal energy range, calculations of four numerical benchmark systems with energy spectra in the intermediate energy range were done. These calculations serve only as an indication of the difference in calculated results that may be expected when the two {sup 233}U cross-section evaluations are used for problems with neutron spectra in the intermediate energy range. Additionally, comparisons of experimental and calculated central fission rate ratios were also made. The study has suggested that an ad hoc {sup 233}U evaluation based on the JENDL library provides better overall results for both fast and thermal experimental critical systems.

  1. Assessment of the Available (Sup 233)U Cross Sections Evaluations in the Calculation of Critical Benchmark Experiments

    SciTech Connect

    Leal, L.C.

    1993-01-01

    In this report we investigate the adequacy of the available {sup 233}U cross-section data for calculation of experimental critical systems. The {sup 233}U evaluations provided in two evaluated nuclear data libraries, the U. S. Data Bank [ENDF/B (Evaluated Nuclear Data Files)] and the Japanese Data Bank [JENDL (Japanese Evaluated Nuclear Data Library)] are examined. Calculations were performed for six thermal and ten fast experimental critical systems using the Sn transport XSDRNPM code. To verify the performance of the {sup 233}U cross-section data for nuclear criticality safety application in which the neutron energy spectrum is predominantly in the epithermal energy range, calculations of four numerical benchmark systems with energy spectra in the intermediate energy range were done. These calculations serve only as an indication of the difference in calculated results that may be expected when the two {sup 233}U cross-section evaluations are used for problems with neutron spectra in the intermediate energy range. Additionally, comparisons of experimental and calculated central fission rate ratios were also made. The study has suggested that an ad hoc {sup 233}U evaluation based on the JENDL library provides better overall results for both fast and thermal experimental critical systems.

  2. The Discourse of Parent Involvement in Special Education: A Critical Analysis Linking Policy Documents to the Experiences of Mothers

    ERIC Educational Resources Information Center

    Lai, Yuan; Vadeboncoeur, Jennifer A.

    2013-01-01

    Parent involvement is acknowledged as a crucial aspect of the education of students with special needs. However, the discourse of parent involvement represents parent involvement in limited ways, thereby controlling how and the extent to which parents can be involved in the education of their children. In this article, critical discourse analysis…

  3. Embedding Culture in a Field Experience Seminar: Lessons Learned about Promoting Preservice Teacher Critical Consciousness in an Urban School Partnership

    ERIC Educational Resources Information Center

    Jacobs, Jennifer; Casciola, Vanessa; Arndt, Katie; Mallory, Mashainah

    2015-01-01

    This article reports the research findings of teacher educator inquiry using qualitative methods examining how incorporating the topic of culture into the field seminar component of a newly developed urban school-university partnership influenced preservice teachers' abilities to become critically conscious. After analyzing preservice teacher…

  4. Using the synergy model of patient care in understanding the lived emergency department experiences of patients, family members and their nurses during critical illness: a phenomenological study.

    PubMed

    Cypress, Brigitte S

    2013-01-01

    Despite many studies conducted aimed to understand and improve emergency care, research on the triad of nurses, patients, and family members looking at the lived emergency department experiences and their perspective of each from the other is notably absent. In a hermeneutic phenomenological study using van Manen's method, a sample of 10 patients, 5 family members, and 8 nurses of a nonprofit community hospital was recruited and interviewed in 2010 to 2011 to explore, understand, and describe their lived experiences during critical illness in the emergency department. The nurses perceived that addressing the patient's physiologic deficit promptly is vital in the emergency department as well as including family members as coparticipants in the care. Patients and family members perceived that communication, critical thinking, sensitivity, and caring are essential for emergency department nurses. The American Association of Critical-Care Nurses' Synergy Model for Patient Care was applied in conceptualizing the findings and served as a framework in recommending practices and interventions geared toward improving competencies required in caring for critically ill patients and their families in the emergency department. The study supports recognizing the patient and family as active participants in the patient's medical care; encouraging family-member presence and creating institutional policies for patient- and family-centered care, as well as encouraging the development of ongoing programs that will recognize, enhance, and support the psychological and emotional well-being of emergency department nurses.

  5. The Effect of Level of Patient Acuity, Critical Care Experience, and ACLS Certification on Clinical Decision Making: Implications for Computer Decision Support Systems

    PubMed Central

    Henry, Suzanne Bakken

    1990-01-01

    This study examined the effect of patient acuity, critical care experience, and ACLS certification on clinical decision making. Each subject (N=68) completed two computerized clinical simulations. Ventricular tachycardia (VT) represented the high acuity situation and atrial flutter (AF) the lower acuity situation. Clinical decision making was measured by proficiency score, patient outcome (cure/die), and amount of data collected. In the AF simulation, proficiency scores were higher (p=.000), more dysrhythmias were cured (p<.005), and more data were collected (p=.040) than in the VT simulation. Experienced and inexperienced nurses did not differ on proficiency score, however, inexperienced nurses collected more data (p=.048) and cured fewer atrial flutter simulations (p=.04). ACLS certified nurses had higher proficiency scores (p=.033) and collected less data (p=.048). Clinical decision making on two simulations was affected by patient acuity, critical care experience, and ACLS certification. These findings have implications for the design and implementation of clinical decision support systems.

  6. 2015 Los Alamos Space Weather Summer School Research Reports

    SciTech Connect

    Cowee, Misa; Chen, Yuxi; Desai, Ravindra; Hassan, Ehab; Kalmoni, Nadine; Lin, Dong; Depascuale, Sebastian; Hughes, Randall Scott; Zhou, Hong

    2015-11-24

    The fifth Los Alamos Space Weather Summer School was held June 1st - July 24th, 2015, at Los Alamos National Laboratory (LANL). With renewed support from the Institute of Geophysics, Planetary Physics, and Signatures (IGPPS) and additional support from the National Aeronautics and Space Administration (NASA) and the Department of Energy (DOE) Office of Science, we hosted a new class of five students from various U.S. and foreign research institutions. The summer school curriculum includes a series of structured lectures as well as mentored research and practicum opportunities. Lecture topics including general and specialized topics in the field of space weather were given by a number of researchers affiliated with LANL. Students were given the opportunity to engage in research projects through a mentored practicum experience. Each student works with one or more LANL-affiliated mentors to execute a collaborative research project, typically linked with a larger ongoing research effort at LANL and/or the student’s PhD thesis research. This model provides a valuable learning experience for the student while developing the opportunity for future collaboration. This report includes a summary of the research efforts fostered and facilitated by the Space Weather Summer School. These reports should be viewed as work-in-progress as the short session typically only offers sufficient time for preliminary results. At the close of the summer school session, students present a summary of their research efforts. Titles of the papers included in this report are as follows: Full particle-in-cell (PIC) simulation of whistler wave generation, Hybrid simulations of the right-hand ion cyclotron anisotropy instability in a sub-Alfvénic plasma flow, A statistical ensemble for solar wind measurements, Observations and models of substorm injection dispersion patterns, Heavy ion effects on Kelvin-Helmholtz instability: hybrid study, Simulating plasmaspheric electron densities with a two

  7. Advances in code validation for mixed-oxide fuel use in light-water reactors through benchmark experiments in the VENUS critical facility

    SciTech Connect

    D'hondt, Pierre; Baeten, Peter; Lance, Bernard; Marloye, Daniel; Basselier, Jacques

    2004-07-01

    Based on the experience accumulated during 25-years of collaboration SCK.CEN together with Belgonucleaire decided to implement a series of Benchmark experiments in the VENUS critical facility in Mol, Belgium in order to give to organizations concerned with MOX fuel the possibility to calibrate and to improve their neutronic calculation tools. In this paper these Benchmark programmes and their outcome are highlighted, they have demonstrated that VENUS is a very flexible and easy to use tool for the investigation of neutronic data as well as for the study of licensing, safety and operation aspects for MOX use in LWR's. (authors)

  8. Alternate measurements of benefit to criticality issues at Hanford

    SciTech Connect

    Toffer, H.; Cabrilla, D.E.

    1997-06-01

    Measurements in a critical mass facility, such as the Los Alamos Critical Experiments Facility, could be performed on simulated nuclear waste materials that would provide important critical mass information and concurrently provide a calibration of alternate measurement techniques. In addition to criticality information, the measurements could also provide a better assessment of diluent material/neutron interaction cross sections. An Hanford, large quantities of fissionable materials are dispersed in tanks, fuel storage pools, and in solid waste. Although the fissionable materials are well diluted by a variety of neutron-moderating and -absorbing substances, it is difficult to assess the margin of subcriticality. A number of measurement approaches are proposed that will either help determine fissionable material concentrations, distributions, or provide a direct measure of subcriticality. The methods under consideration involve passive neutron counting, active neutron measurements, pulse neutron applications, neutron noise analyses, and cover gas evaluations. Active neutron measurements can also provide insight into the determination of neutron absorber concentrations. Efforts are underway to test some of the methods in actual waste tank environments and geometries. It is important that these methods be tested and calibrated in a critical mass facility.

  9. Experiments of drops impacting a smooth solid surface: a model of the critical impact speed for drop splashing.

    PubMed

    Riboux, Guillaume; Gordillo, José Manuel

    2014-07-11

    Making use of experimental and theoretical considerations, in this Letter we deduce a criterion to determine the critical velocity for which a drop impacting a smooth dry surface either spreads over the substrate or disintegrates into smaller droplets. The derived equation, which expresses the splash threshold velocity as a function of the material properties of the two fluids involved, the drop radius, and the mean free path of the molecules composing the surrounding gaseous atmosphere, has been thoroughly validated experimentally at normal atmospheric conditions using eight different liquids with viscosities ranging from μ=3×10(-4) to μ=10(-2)  Pa s, and interfacial tension coefficients varying between σ=17 and σ=72  mN m(-1). Our predictions are also in fair agreement with the measured critical speed of drops impacting in different gases at reduced pressures given by Xu et al. [Phys. Rev. Lett. 94, 184505 (2005). PMID:25062193

  10. Experiments of drops impacting a smooth solid surface: a model of the critical impact speed for drop splashing.

    PubMed

    Riboux, Guillaume; Gordillo, José Manuel

    2014-07-11

    Making use of experimental and theoretical considerations, in this Letter we deduce a criterion to determine the critical velocity for which a drop impacting a smooth dry surface either spreads over the substrate or disintegrates into smaller droplets. The derived equation, which expresses the splash threshold velocity as a function of the material properties of the two fluids involved, the drop radius, and the mean free path of the molecules composing the surrounding gaseous atmosphere, has been thoroughly validated experimentally at normal atmospheric conditions using eight different liquids with viscosities ranging from μ=3×10(-4) to μ=10(-2)  Pa s, and interfacial tension coefficients varying between σ=17 and σ=72  mN m(-1). Our predictions are also in fair agreement with the measured critical speed of drops impacting in different gases at reduced pressures given by Xu et al. [Phys. Rev. Lett. 94, 184505 (2005).

  11. Los Alamos experimental capabilities: Ancho Canyon high explosives and pulse power facilities

    SciTech Connect

    Morris, C.E.

    1993-02-01

    This document outlines the Ancho Canyon testing facility comprehensive material characterization capabilities. These include the high explosive (HE) firing sites, a full complement of gun facilities, and variety of pulse power capacitor bank systems of various energies. The explosive fabrication capability at Los Alamos allows the design and testing of unique HE experimental assemblies. Depending on the hydrodynamic requirements, these explosive systems can vary widely in cost. Years of experience have enabled the development of a comprehensive set of diagnostics to monitor these experiments.

  12. Los Alamos experimental capabilities: Ancho Canyon high explosives and pulse power facilities

    SciTech Connect

    Morris, C.E.

    1993-01-01

    This document outlines the Ancho Canyon testing facility comprehensive material characterization capabilities. These include the high explosive (HE) firing sites, a full complement of gun facilities, and variety of pulse power capacitor bank systems of various energies. The explosive fabrication capability at Los Alamos allows the design and testing of unique HE experimental assemblies. Depending on the hydrodynamic requirements, these explosive systems can vary widely in cost. Years of experience have enabled the development of a comprehensive set of diagnostics to monitor these experiments.

  13. New Developments in Proton Radiography at the Los Alamos Neutron Science Center (LANSCE)

    SciTech Connect

    Morris, C. L.; Brown, E. N.; Agee, C.; Bernert, T.; Bourke, M. A. M.; Burkett, M. W.; Buttler, W. T.; Byler, D. D.; Chen, C. F.; Clarke, A. J.; Cooley, J. C.; Gibbs, P. J.; Imhoff, S. D.; Jones, R.; Kwiatkowski, K.; Mariam, F. G.; Merrill, F. E.; Murray, M. M.; Olinger, C. T.; Oro, D. M.; Nedrow, P.; Saunders, A.; Terrones, G.; Trouw, F.; Tupa, D.; Vogan, W.; Winkler, B.; Wang, Z.; Zellner, M. B.

    2015-12-30

    An application of nuclear physics, a facility for using protons for flash radiography, was developed at the Los Alamos Neutron Science Center (LANSCE). Protons have proven far superior to high energy x-rays for flash radiography because of their long mean free path, good position resolution, and low scatter background. Although this facility is primarily used for studying very fast phenomena such as high explosive driven experiments, it is finding increasing application to other fields, such as tomography of static objects, phase changes in materials and the dynamics of chemical reactions. The advantages of protons are discussed, data from some recent experiments will be reviewed and concepts for new techniques are introduced.

  14. Explosive Flux Compression: 50 Years of Los Alamos Activities

    SciTech Connect

    Fowler, C.M.; Thomson, D.B.; Garn, W.B.

    1998-10-18

    Los Alamos flux compression activities are surveyed, mainly through references in view of space limitations. However, two plasma physics programs done with Sandia National Laboratory are discussed in more detail.

  15. Review of liquid metal heat pipe work at Los Alamos

    NASA Astrophysics Data System (ADS)

    Reid, Robert S.; Merrigan, Michael A.; Sena, J. Tom

    A survey of space-power related liquid metal heat pipe work at Los Alamos National Laboratory is presented. Heat pipe development at Los Alamos has been on-going since 1963. Heat pipes were initially developed for thermionic nuclear-electrical power production in space. Since then Los Alamos has developed liquid metal heat pipes for numerous applications related to high temperature systems in both the space and terrestrial environments. Some of these applications include thermionic electrical generators, thermoelectric energy conversion (both in-core and direct radiation), thermal energy storage, hypersonic vehicle leading edge cooling, and heat pipe vapor laser cells. Some of the work performed at Los Alamos has been documented in internal reports that are often little-known. A representative description and summary of progress in space-related liquid metal heat pipe technology is provided followed by a reference section citing sources where these works may be found.

  16. Review of liquid metal heat pipe work at Los Alamos

    SciTech Connect

    Reid, R.S.; Merrigan, M.A.; Sena, J.T. )

    1991-01-10

    A survey of space-power related liquid metal heat pipe work at Los Alamos National Laboratory is presented. Heat pipe development at Los Alamos has been on-going since 1963. Heat pipes were initially developed for thermionic nuclear-electrical power production in space. Since then Los Alamos has developed liquid metal heat pipes for numerous applications related to high temperature systems in both the space and terrestrial environments. Some of these applications include thermionic electrical generators, thermoelectric energy conversion (both in-core and direct radiation), thermal energy storage, hypersonic vehicle leading edge cooling, and heat pipe vapor laser cells. Some of the work performed at Los Alamos has been documented in internal reports that are often little-known. A representative description and summary of progress in space-related liquid metal heat pipe technology is provided followed by a reference section citing sources where these works may be found.

  17. Review of liquid metal heat pipe work at Los Alamos

    NASA Astrophysics Data System (ADS)

    Reid, Robert S.; Merrigan, Michael A.; Sena, J. Tom

    1991-01-01

    A survey of space-power related liquid metal heat pipe work at Los Alamos National Laboratory is presented. Heat pipe development at Los Alamos has been on-going since 1963. Heat pipes were initially developed for thermionic nuclear-electrical power production in space. Since then Los Alamos has developed liquid metal heat pipes for numerous applications related to high temperature systems in both the space and terrestrial environments. Some of these applications include thermionic electrical generators, thermoelectric energy conversion (both in-core and direct radiation), thermal energy storage, hypersonic vehicle leading edge cooling, and heat pipe vapor laser cells. Some of the work performed at Los Alamos has been documented in internal reports that are often little-known. A representative description and summary of progress in space-related liquid metal heat pipe technology is provided followed by a reference section citing sources where these works may be found.

  18. Review of liquid metal heat pipe work at Los Alamos

    NASA Astrophysics Data System (ADS)

    Reid, Robert S.; Merrigan, Michael A.; Sena, J. T.

    A survey of space-power related liquid metal heat pipe work at Los Alamos National Laboratory is presented. Heat pipe development at Los Alamos has been on-going since 1963. Heat pipes were initially developed for thermionic nuclear-electrical power production in space. Since then Los Alamos has developed liquid metal heat pipes for numerous applications related to high temperature systems in both the space and terrestrial environments. Some of these applications include thermionic electrical generators, thermoelectric energy conversion (both in-core and direct radiation), thermal energy storage, hypersonic vehicle leading edge cooling, and heat pipe vapor laser cells. Some of the work performed at Los Alamos has been documented in internal reports that are often little-known. A representative description and summary of progress in space-related liquid metal heat pipe technology is provided followed by reference section citing sources where these works may be found.

  19. Review of liquid metal heat pipe work at Los Alamos

    SciTech Connect

    Reid, R.S.; Merrigan, M.A.; Sena, J.T.

    1990-01-01

    A survey of space-power related liquid metal heat pipe work at Los Alamos National Laboratory is presented. Heat pipe development at Los Alamos has been on-going since 1963. Heat pipes were initially developed for thermionic nuclear-electrical power production in space. Since then Los Alamos has developed liquid metal heat pipes for numerous applications related to high temperature systems in both the space and terrestrial environments. Some of these applications include thermionic electrical generators, thermoelectric energy conversion (both in-core and direct radiation), thermal energy storage, hypersonic vehicle leading edge cooling, and heat pipe vapor laser cells. Some of the work performed at Los Alamos has been documented in internal reports that are often little-known. A representative description and summary of progress in space-related liquid metal heat pipe technology is provided followed by a reference section citing sources where these works may be found. 53 refs.

  20. Environmental Surveillance at Los Alamos during 2007

    SciTech Connect

    2008-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (the Laboratory) Environmental Directorate, as required by US Department of Energy Order 450.1, General Environmental Protection Program, and US Department of Energy Order 231.1A, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory’s efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory’s major environmental programs and explains the risks and the actions taken to reduce risks at the Laboratory from environmental legacies and waste management operations. Chapter 2 reports the Laboratory’s compliance status for 2007. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations and discusses chemical exposures. The environmental surveillance and monitoring data are organized by environmental media (Chapter 4, air; Chapters 5 and 6, water and sediments; Chapter 7, soils; and Chapter 8, foodstuffs and biota) in a format to meet the needs of a general and scientific audience. Chapter 9 provides a summary of the status of environmental restoration work around LANL. A glossary and a list of acronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the laboratory’s technical areas and their associated programs, and Appendix D provides web links to more information. In printed copies of this report or Executive Summary, we have

  1. Strategic defense initiatives at Los Alamos National Laboratory

    SciTech Connect

    Rockwood, S.D.

    1985-01-01

    This presentation reviews the Strategic Defense Initiative (SDI) programs at Los Alamos National Laboratory, noting especially the needs for and applications of optics and optical technologies. Table I lists the various activities at Los Alamos contributing to SDI programs. The principal, nonnuclear SDI programs are: (1) the free-electron laser, and (2) neutral particle beams. Both should be considered as potential long-range-kill systems, but still in the futuristic category.

  2. Micrometer-sized ice particles for planetary-science experiments - I. Preparation, critical rolling friction force, and specific surface energy

    NASA Astrophysics Data System (ADS)

    Gundlach, B.; Kilias, S.; Beitz, E.; Blum, J.

    2011-08-01

    Coagulation models assume a higher sticking threshold for micrometer-sized ice particles than for micrometer-sized silicate particles. However, in contrast to silicates, laboratory investigations of the collision properties of micrometer-sized ice particles (in particular, of the most abundant H 2O-ice) have not been conducted yet. Thus, we used two different experimental methods to produce micrometer-sized H 2O-ice particles, i.e. by spraying H 2O droplets into liquid nitrogen and by spraying H 2O droplets into a cold nitrogen atmosphere. The mean particle radii of the ice particles produced with these experimental methods are (1.49 ± 0.79) μm and (1.45 ± 0.65) μm. Ice aggregates composed of the micrometer-sized ice particles are highly porous (volume filling factor: ϕ = 0.11 ± 0.01) or rather compact (volume filling factor: ϕ = 0.72 ± 0.04), depending on the method of production. Furthermore, the critical rolling friction force of FRoll, ice = (114.8 ± 23.8) × 10 -10 N was measured for micrometer-sized ice particles, which exceeds the critical rolling friction force of micrometer-sized SiO 2 particles (F=(12.1±3.6)×10-10N). This result implies that the adhesive bonding between micrometer-sized ice particles is stronger than the bonding strength between SiO 2 particles. An estimation of the specific surface energy of micrometer-sized ice particles, derived from the measured critical rolling friction forces and the surface energy of micrometer-sized SiO 2 particles, results in γice = 0.190 J m -2.

  3. Los Alamos low-level waste performance assessment status

    SciTech Connect

    Wenzel, W.J.; Purtymun, W.D.; Dewart, J.M.; Rodgers, J.E.

    1986-06-01

    This report reviews the documented Los Alamos studies done to assess the containment of buried hazardous wastes. Five sections logically present the environmental studies, operational source terms, transport pathways, environmental dosimetry, and computer model development and use. This review gives a general picture of the Los Alamos solid waste disposal and liquid effluent sites and is intended for technical readers with waste management and environmental science backgrounds but without a detailed familiarization with Los Alamos. The review begins with a wide perspective on environmental studies at Los Alamos. Hydrology, geology, and meteorology are described for the site and region. The ongoing Laboratory-wide environmental surveillance and waste management environmental studies are presented. The next section describes the waste disposal sites and summarizes the current source terms for these sites. Hazardous chemical wastes and liquid effluents are also addressed by describing the sites and canyons that are impacted. The review then focuses on the transport pathways addressed mainly in reports by Healy and Formerly Utilized Sites Remedial Action Program. Once the source terms and potential transport pathways are described, the dose assessment methods are addressed. Three major studies, the waste alternatives, Hansen and Rogers, and the Pantex Environmental Impact Statement, contributed to the current Los Alamos dose assessment methodology. Finally, the current Los Alamos groundwater, surface water, and environmental assessment models for these mesa top and canyon sites are described.

  4. The Prompt Fission Neutron Spectrum: From Experiment to the Evaluated Data and its Impact on Critical Assemblies

    SciTech Connect

    Rising, Michael Evan

    2015-06-10

    After a brief introduction concerning nuclear data, prompt fission neutron spectrum (PFNS) evaluations and the limited PFNS covariance data in the ENDF/B-VII library, and the important fact that cross section uncertainties ~ PFNS uncertainties, the author presents background information on the PFNS (experimental data, theoretical models, data evaluation, uncertainty quantification) and discusses the impact on certain well-known critical assemblies with regard to integral quantities, sensitivity analysis, and uncertainty propagation. He sketches recent and ongoing research and concludes with some final thoughts.

  5. Assessment of TRAC-PF1/MOD1 version 14. 3 using separate effects critical flow and blowdown experiments

    SciTech Connect

    Spindler, B.; Pellissier, M. )

    1990-01-01

    Independent assessment of the TRAC code was conducted at the Centre d'Etudes Nucleaires de Grenoble of the Commissariate a l'Energie Atomique (France) in the frame of the ICAP. This report presents the results of the assessment of TRAC-PF1/MOD1 version 14.3 using critical flow steady state tests (MOBY-DICK, SUPER-MOBY-DICK), and blowdown tests (CANON, SUPER-CANON, VERTICAL-CANON, MARVIKEN, OMEGA-TUBE, OMEGA-BUNDLE). This document, Volume 1, presents the text and tables from this assessment.

  6. Assessment of TRAC-PF1/MOD1 Version 14. 3 using separate effects critical flow and blowdown experiments

    SciTech Connect

    Spindler, B.; Pellissier, M. )

    1990-01-01

    Independent assessment of the TRAC code was conducted at the Centre d'Etudes Nucleaires de Grenoble of the Commissariate a l'Energie Atomique (France) in the frame of the ICAP. This report presents the results of the assessment of TRAC-PF1/MOD1 version 14.3 using critical flow steady state tests (MOBY-DICK, SUPER-MOBY-DICK), and blowdown tests (CANON, SUPER-CANON, VERTICAL-CANON, MARVIKEN, OMEGA-TUBE, OMEGA-BUNDLE). This document, Volume 2, presents the experimental data and figures from the assessment.

  7. A Tracer Test at the Los Alamos Canyon Weir

    NASA Astrophysics Data System (ADS)

    Levitt, D. G.; Stone, W. J.; Newell, D. L.; Wykoff, D. S.

    2002-12-01

    A low-head weir was constructed in the Los Alamos Canyon to reduce the transport of contaminant-bearing sediment caused by fire-enhanced runoff off Los Alamos National Laboratory (LANL) property towards the Rio Grande following the May 2000 Cerro Grande fire at Los Alamos, New Mexico. Fractured basalt was exposed in the channel by grading during construction of the weir, and water temporarily ponds behind the weir following periods of runoff. In order to monitor any downward transport of contaminants into fractured basalt, and potentially downward to the regional ground water, three boreholes (one vertical, one at 43 degrees, and one at 34 degrees from horizontal) were installed for environmental monitoring. The boreholes penetrate to depths ranging from approximately 9 to 82 m below the weir floor. The two angled boreholes are fitted with flexible FLUTe liners with resistance sensors to measure relative moisture content and absorbent sampling pads for contaminant and environmental tracer sampling within the vadose zone. The two angled boreholes are also monitored for relative changes in moisture content by neutron logging. The vertical borehole penetrates three perched water zones and is equipped with four screens and sampling ports. In April 2002, a tracer test was initiated with the application of a 0.2 M (16,000 ppm) solution of potassium bromide (KBr) onto the weir floor. The tracer experiment was intended to provide data on travel times through the complex hydrogeologic media of fractured basalt. A precipitation and runoff event in June 2002 resulted in approximately 0.61 m of standing water behind the weir. If the KBr and flood waters were well mixed, the concentration of KBr in the flood waters was approximately 24 ppm. Bromide was detected in the absorbent membrane in the 43 degree hole at concentrations up to 2 ppm. Resistance sensors in the 43 degree borehole detected moisture increases within 3 days at a depth of 27 m, indicating an average wetting

  8. Electron clearing in the Los Alamos Proton Storage Ring

    SciTech Connect

    Plum, M.A.; Allen, J.; Borden, M.J.; Fitzgerald, D.H.; Macek, R.J.; Wang, T.S.

    1995-05-01

    The instability observed in the Los Alamos Proton Storage Ring (PSR) has been tentatively identified as an electron-proton instability. A source of electrons must exist for this instability to occur. The PSR injection section contains the stripper foil, and therefore provides several strong sources of electrons. An electron clearing system was installed in the injection section to clear out these electrons. The system comprised: (1) a foil biasing system to clear the SEM and thermionic electrons, (2) a pair of low-field bending magnets with a Faraday cup to clear the convoy electrons, and (3) two pairs of clearing electrodes, one upstream and one downstream of the stripper foil, to clear the remaining electrons. This paper discusses the design and performance of the Electron Clearing System, and its effect on the instability. Also presented are some results from other charge-collection experiments that suggest there is also substantial electron production in parts of the ring other than the injection section.

  9. Development and validation of a critical gradient energetic particle driven Alfven eigenmode transport model for DIII-D tilted neutral beam experiments

    NASA Astrophysics Data System (ADS)

    Waltz, R. E.; Bass, E. M.; Heidbrink, W. W.; VanZeeland, M. A.

    2015-11-01

    Recent experiments with the DIII-D tilted neutral beam injection (NBI) varying the beam energetic particle (EP) source profiles have provided strong evidence that unstable Alfven eigenmodes (AE) drive stiff EP transport at a critical EP density gradient [Heidbrink et al 2013 Nucl. Fusion 53 093006]. Here the critical gradient is identified by the local AE growth rate being equal to the local ITG/TEM growth rate at the same low toroidal mode number. The growth rates are taken from the gyrokinetic code GYRO. Simulation show that the slowing down beam-like EP distribution has a slightly lower critical gradient than the Maxwellian. The ALPHA EP density transport code [Waltz and Bass 2014 Nucl. Fusion 54 104006], used to validate the model, combines the low-n stiff EP critical density gradient AE mid-core transport with the Angioni et al (2009 Nucl. Fusion 49 055013) energy independent high-n ITG/TEM density transport model controling the central core EP density profile. For the on-axis NBI heated DIII-D shot 146102, while the net loss to the edge is small, about half the birth fast ions are transported from the central core r/a  <  0.5 and the central density is about half the slowing down density. These results are in good agreement with experimental fast ion pressure profiles inferred from MSE constrained EFIT equilibria.

  10. The Los Alamos high-brightness photoinjector

    SciTech Connect

    O'Shea, P.G.

    1991-01-01

    For a number of years Los Alamos National Laboratory has been developing photocathode RF guns for high-brightness electron beam applications such as free-electron lasers (FELs). Previously thermionic high-voltage guns have been the source of choice for the electron accelerators used to drive FELs. The performance of such FELs is severely limited by the emittance growth produced by the subharmonic bunching process and also by the low peak current of the source. In a photoinjector, a laser driven photocathode is placed directly in a high-gradient RF accelerating cavity. A photocathode allows unsurpassed control over the current, and the spatial and temporal profile of the beam. In addition the electrodeless emission'' avoids many of the difficulties associated with multi-electrode guns, i.e. the electrons are accelerated very rapidly to relativistic energies, and there are no electrodes to distort the accelerating fields. For the past two years we have been integrating a photocathode into our existing FEL facility by replacing our thermionic gun and subharmonic bunchers with a high-gradient 1.3 GHz photoinjector. The photoinjector, which is approximately 0.6 m in length, produces 6 MeV, 300 A, 15 ps linac, and accelerated to a final energy of 40 MeV. We have recently begun lasing at wavelengths near 3 {mu}m. 16 refs., 2 figs., 5 tabs.

  11. NIST--Los Alamos racetrack microtron status

    SciTech Connect

    Wilson, M.A.; Ayres, R.L.; Cutler, R.I.; Debenham, P.H.; Lindstrom, E.R.; Mohr, D.L.; Penner, S.; Rose, J.E.; Young, L.M.

    1988-01-01

    The NIST-Los Alamos Racetrack Microtron (RTM) is designed to deliver a low-emittance electron beam of up to 0.5 mA cw over an energy range of 17 MeV to 185 MeV. Fed by a 5 MeV injector, the RTM contains two 180/degree/ end magnets that recirculate the beam up to 15 times through a 12 MeV RF linac. The linac, which operates in a standing-wave mode at 2380 MHz, has been tested to nearly full RF power. At present, the injector has undergone beam tests, and the beam transport system is complete through the 12 MeV linac. A temporary beam line has been installed at the exit of one end magnet to measure the beam energy, energy spread, and emittance after one pass through the accelerator. Preliminary results indicate that the accelerated beam energy spread and emittance are within design goals. 4 refs., 7 figs.

  12. Expanded recycling at Los Alamos National Laboratory

    SciTech Connect

    Betschart, J.F.; Malinauskas, L.; Burns, M.

    1996-07-01

    The Pollution Prevention Program Office has increased recycling activities, reuse, and options to reduce the solid waste streams through streamlining efforts that applied best management practices. The program has prioritized efforts based on volume and economic considerations and has greatly increased Los Alamos National Laboratory`s (LANL`s) recycle volumes. The Pollution Prevention Program established and chairs a Solid Waste Management Solutions Group to specifically address and solve problems in nonradioactive, Resource Conservation and Recovery Act (RCRA), state-regulated, and sanitary and industrial waste streams (henceforth referred to as sanitary waste in this paper). By identifying materials with recycling potential, identifying best management practices and pathways to return materials for reuse, and introducing the concept and practice of {open_quotes}asset management,{open_quotes} the Group will divert much of the current waste stream from disposal. This Group is developing procedures, agreements, and contracts to stage, collect, sort, segregate, transport and process materials, and is also garnering support for the program through the involvement of upper management, facility managers, and generators.

  13. Saving Water at Los Alamos National Laboratory

    SciTech Connect

    Erickson, Andy

    2015-03-16

    Los Alamos National Laboratory decreased its water usage by 26 percent in 2014, with about one-third of the reduction attributable to using reclaimed water to cool a supercomputing center. The Laboratory's goal during 2014 was to use only re-purposed water to support the mission at the Strategic Computing Complex. Using reclaimed water from the Sanitary Effluent Reclamation Facility, or SERF, substantially decreased water usage and supported the overall mission. SERF collects industrial wastewater and treats it for reuse. The reclamation facility contributed more than 27 million gallons of re-purposed water to the Laboratory's computing center, a secured supercomputing facility that supports the Laboratory’s national security mission and is one of the institution’s larger water users. In addition to the strategic water reuse program at SERF, the Laboratory reduced water use in 2014 by focusing conservation efforts on areas that use the most water, upgrading to water-conserving fixtures, and repairing leaks identified in a biennial survey.

  14. A design of experiments test to define critical spray cleaning parameters for Brulin 815 GD and Jettacin cleaners

    NASA Technical Reports Server (NTRS)

    Keen, Jill M.; Evans, Kurt B.; Schiffman, Robert L.; Deweese, C. Darrell; Prince, Michael E.

    1995-01-01

    Experimental design testing was conducted to identify critical parameters of an aqueous spray process intended for cleaning solid rocket motor metal components (steel and aluminum). A two-level, six-parameter, fractional factorial matrix was constructed and conducted for two cleaners, Brulin 815 GD and Diversey Jettacin. The matrix parameters included cleaner temperature and concentration, wash density, wash pressure, rinse pressure, and dishwasher type. Other spray parameters: nozzle stand-off, rinse water temperature, wash and rinse time, dry conditions, and type of rinse water (deionized) were held constant. Matrix response testing utilized discriminating bond specimens (fracture energy and tensile adhesion strength) which represent critical production bond lines. Overall, Jettacin spray cleaning was insensitive to the range of conditions tested for all parameters and exhibited bond strengths significantly above the TCA test baseline for all bond lines tested. Brulin 815 was sensitive to cleaning temperature, but produced bond strengths above the TCA test baseline even at the lower temperatures. Ultimately, the experimental design database was utilized to recommend process parameter settings for future aqueous spray cleaning characterization work.

  15. Rotational symmetry breaking in the topological superconductor SrxBi2Se3 probed by upper-critical field experiments.

    PubMed

    Pan, Y; Nikitin, A M; Araizi, G K; Huang, Y K; Matsushita, Y; Naka, T; de Visser, A

    2016-01-01

    Recently it was demonstrated that Sr intercalation provides a new route to induce superconductivity in the topological insulator Bi2Se3. Topological superconductors are predicted to be unconventional with an odd-parity pairing symmetry. An adequate probe to test for unconventional superconductivity is the upper critical field, Bc2. For a standard BCS layered superconductor Bc2 shows an anisotropy when the magnetic field is applied parallel and perpendicular to the layers, but is isotropic when the field is rotated in the plane of the layers. Here we report measurements of the upper critical field of superconducting SrxBi2Se3 crystals (Tc = 3.0 K). Surprisingly, field-angle dependent magnetotransport measurements reveal a large anisotropy of Bc2 when the magnet field is rotated in the basal plane. The large two-fold anisotropy, while six-fold is anticipated, cannot be explained with the Ginzburg-Landau anisotropic effective mass model or flux flow induced by the Lorentz force. The rotational symmetry breaking of Bc2 indicates unconventional superconductivity with odd-parity spin-triplet Cooper pairs (Δ4-pairing) recently proposed for rhombohedral topological superconductors, or might have a structural nature, such as self-organized stripe ordering of Sr atoms. PMID:27350295

  16. Establishing a Wild, Ex Situ Population of a Critically Endangered Shade-Tolerant Rainforest Conifer: A Translocation Experiment

    PubMed Central

    Zimmer, Heidi C.; Offord, Catherine A.; Auld, Tony D.; Baker, Patrick J.

    2016-01-01

    Translocation can reduce extinction risk by increasing population size and geographic range, and is increasingly being used in the management of rare and threatened plant species. A critical determinant of successful plant establishment is light environment. Wollemia nobilis (Wollemi pine) is a critically endangered conifer, with a wild population of 83 mature trees and a highly restricted distribution of less than 10 km2. We used under-planting to establish a population of W. nobilis in a new rainforest site. Because its optimal establishment conditions were unknown, we conducted an experimental translocation, planting in a range of different light conditions from deeply shaded to high light gaps. Two years after the experimental translocation, 85% of plants had survived. There were two distinct responses: very high survival (94%) but very low growth, and lower survival (69%) and higher growth, associated with initial plant condition. Overall survival of translocated W. nobilis was strongly increased in planting sites with higher light, in contrast to previous studies demonstrating long-term survival of wild W. nobilis juveniles in deep shade. Translocation by under-planting may be useful in establishing new populations of shade-tolerant plant species, not least by utilizing the range of light conditions that occur in forest understories. PMID:27403527

  17. Rotational symmetry breaking in the topological superconductor SrxBi2Se3 probed by upper-critical field experiments

    PubMed Central

    Pan, Y.; Nikitin, A. M.; Araizi, G. K.; Huang, Y. K.; Matsushita, Y.; Naka, T.; de Visser, A.

    2016-01-01

    Recently it was demonstrated that Sr intercalation provides a new route to induce superconductivity in the topological insulator Bi2Se3. Topological superconductors are predicted to be unconventional with an odd-parity pairing symmetry. An adequate probe to test for unconventional superconductivity is the upper critical field, Bc2. For a standard BCS layered superconductor Bc2 shows an anisotropy when the magnetic field is applied parallel and perpendicular to the layers, but is isotropic when the field is rotated in the plane of the layers. Here we report measurements of the upper critical field of superconducting SrxBi2Se3 crystals (Tc = 3.0 K). Surprisingly, field-angle dependent magnetotransport measurements reveal a large anisotropy of Bc2 when the magnet field is rotated in the basal plane. The large two-fold anisotropy, while six-fold is anticipated, cannot be explained with the Ginzburg-Landau anisotropic effective mass model or flux flow induced by the Lorentz force. The rotational symmetry breaking of Bc2 indicates unconventional superconductivity with odd-parity spin-triplet Cooper pairs (Δ4-pairing) recently proposed for rhombohedral topological superconductors, or might have a structural nature, such as self-organized stripe ordering of Sr atoms. PMID:27350295

  18. Establishing a Wild, Ex Situ Population of a Critically Endangered Shade-Tolerant Rainforest Conifer: A Translocation Experiment.

    PubMed

    Zimmer, Heidi C; Offord, Catherine A; Auld, Tony D; Baker, Patrick J

    2016-01-01

    Translocation can reduce extinction risk by increasing population size and geographic range, and is increasingly being used in the management of rare and threatened plant species. A critical determinant of successful plant establishment is light environment. Wollemia nobilis (Wollemi pine) is a critically endangered conifer, with a wild population of 83 mature trees and a highly restricted distribution of less than 10 km2. We used under-planting to establish a population of W. nobilis in a new rainforest site. Because its optimal establishment conditions were unknown, we conducted an experimental translocation, planting in a range of different light conditions from deeply shaded to high light gaps. Two years after the experimental translocation, 85% of plants had survived. There were two distinct responses: very high survival (94%) but very low growth, and lower survival (69%) and higher growth, associated with initial plant condition. Overall survival of translocated W. nobilis was strongly increased in planting sites with higher light, in contrast to previous studies demonstrating long-term survival of wild W. nobilis juveniles in deep shade. Translocation by under-planting may be useful in establishing new populations of shade-tolerant plant species, not least by utilizing the range of light conditions that occur in forest understories. PMID:27403527

  19. Critical Heat Flux Phenomena at HighPressure & Low Mass Fluxes: NEUP Final Report Part I: Experiments

    SciTech Connect

    Corradini, Michael; Wu, Qiao

    2015-04-30

    This report is a preliminary document presenting an overview of the Critical Heat Flux (CHF) phenomenon, the High Pressure Critical Heat Flux facility (HPCHF), preliminary CHF data acquired, and the future direction of the research. The HPCHF facility has been designed and built to study CHF at high pressure and low mass flux ranges in a rod bundle prototypical of conceptual Small Modular Reactor (SMR) designs. The rod bundle is comprised of four electrically heated rods in a 2x2 square rod bundle with a prototypic chopped-cosine axial power profile and equipped with thermocouples at various axial and circumferential positions embedded in each rod for CHF detection. Experimental test parameters for CHF detection range from pressures of ~80 – 160 bar, mass fluxes of ~400 – 1500 kg/m2s, and inlet water subcooling from ~30 – 70°C. The preliminary data base established will be further extended in the future along with comparisons to existing CHF correlations, models, etc. whose application ranges may be applicable to the conditions of SMRs.

  20. Establishing a Wild, Ex Situ Population of a Critically Endangered Shade-Tolerant Rainforest Conifer: A Translocation Experiment.

    PubMed

    Zimmer, Heidi C; Offord, Catherine A; Auld, Tony D; Baker, Patrick J

    2016-01-01

    Translocation can reduce extinction risk by increasing population size and geographic range, and is increasingly being used in the management of rare and threatened plant species. A critical determinant of successful plant establishment is light environment. Wollemia nobilis (Wollemi pine) is a critically endangered conifer, with a wild population of 83 mature trees and a highly restricted distribution of less than 10 km2. We used under-planting to establish a population of W. nobilis in a new rainforest site. Because its optimal establishment conditions were unknown, we conducted an experimental translocation, planting in a range of different light conditions from deeply shaded to high light gaps. Two years after the experimental translocation, 85% of plants had survived. There were two distinct responses: very high survival (94%) but very low growth, and lower survival (69%) and higher growth, associated with initial plant condition. Overall survival of translocated W. nobilis was strongly increased in planting sites with higher light, in contrast to previous studies demonstrating long-term survival of wild W. nobilis juveniles in deep shade. Translocation by under-planting may be useful in establishing new populations of shade-tolerant plant species, not least by utilizing the range of light conditions that occur in forest understories.

  1. Rotational symmetry breaking in the topological superconductor SrxBi2Se3 probed by upper-critical field experiments.

    PubMed

    Pan, Y; Nikitin, A M; Araizi, G K; Huang, Y K; Matsushita, Y; Naka, T; de Visser, A

    2016-01-01

    Recently it was demonstrated that Sr intercalation provides a new route to induce superconductivity in the topological insulator Bi2Se3. Topological superconductors are predicted to be unconventional with an odd-parity pairing symmetry. An adequate probe to test for unconventional superconductivity is the upper critical field, Bc2. For a standard BCS layered superconductor Bc2 shows an anisotropy when the magnetic field is applied parallel and perpendicular to the layers, but is isotropic when the field is rotated in the plane of the layers. Here we report measurements of the upper critical field of superconducting SrxBi2Se3 crystals (Tc = 3.0 K). Surprisingly, field-angle dependent magnetotransport measurements reveal a large anisotropy of Bc2 when the magnet field is rotated in the basal plane. The large two-fold anisotropy, while six-fold is anticipated, cannot be explained with the Ginzburg-Landau anisotropic effective mass model or flux flow induced by the Lorentz force. The rotational symmetry breaking of Bc2 indicates unconventional superconductivity with odd-parity spin-triplet Cooper pairs (Δ4-pairing) recently proposed for rhombohedral topological superconductors, or might have a structural nature, such as self-organized stripe ordering of Sr atoms.

  2. Rotational symmetry breaking in the topological superconductor SrxBi2Se3 probed by upper-critical field experiments

    NASA Astrophysics Data System (ADS)

    Pan, Y.; Nikitin, A. M.; Araizi, G. K.; Huang, Y. K.; Matsushita, Y.; Naka, T.; de Visser, A.

    2016-06-01

    Recently it was demonstrated that Sr intercalation provides a new route to induce superconductivity in the topological insulator Bi2Se3. Topological superconductors are predicted to be unconventional with an odd-parity pairing symmetry. An adequate probe to test for unconventional superconductivity is the upper critical field, Bc2. For a standard BCS layered superconductor Bc2 shows an anisotropy when the magnetic field is applied parallel and perpendicular to the layers, but is isotropic when the field is rotated in the plane of the layers. Here we report measurements of the upper critical field of superconducting SrxBi2Se3 crystals (Tc = 3.0 K). Surprisingly, field-angle dependent magnetotransport measurements reveal a large anisotropy of Bc2 when the magnet field is rotated in the basal plane. The large two-fold anisotropy, while six-fold is anticipated, cannot be explained with the Ginzburg-Landau anisotropic effective mass model or flux flow induced by the Lorentz force. The rotational symmetry breaking of Bc2 indicates unconventional superconductivity with odd-parity spin-triplet Cooper pairs (Δ4-pairing) recently proposed for rhombohedral topological superconductors, or might have a structural nature, such as self-organized stripe ordering of Sr atoms.

  3. Hydronuclear experiments

    SciTech Connect

    Thorn, R.N.; Westervelt, D.R.

    1987-02-01

    Hydronuclear experiments, a method for assessing some aspects of nuclear weapon safety, were conducted at Los Alamos during the 1958 to 1961 moratorium on nuclear testing. The experiments resulted in subcritical multiplying assemblies or a very slight degree of supercriticality and, in some cases, involved a slight, but insignificant, fission energy release. These experiments helped to identify so-called one-point safety problems associated with some of the nuclear weapons systems of that time. The need for remedial action was demonstrated, although some of the necessary design changes could not be made until after the resumption of weapons testing at the end of 1961.

  4. Optimization of Fast Critical Experiments to Reduce Nuclear Data Uncertainties in Support of a Fast Burner Reactor Design Concept

    NASA Astrophysics Data System (ADS)

    Stover, Tracy E., Jr.

    An optimization technique has been developed to select optimized experimental design specifications to produce data specifically designed to be assimilated to optimize a given reactor concept. Data from the optimized experiment is assimilated to generate posteriori uncertainties on the reactor concept's core attributes from which the design responses are computed. The reactor concept is then optimized with the new data to realize cost savings by reducing margin. The optimization problem iterates until an optimal experiment is found to maximize the savings. A new generation of innovative nuclear reactor designs, in particular fast neutron spectrum recycle reactors, are being considered for the application of closing the nuclear fuel cycle in the future. Safe and economical design of these reactors will require uncertainty reduction in basic nuclear data which are input to the reactor design. These data uncertainty propagate to design responses which in turn require the reactor designer to incorporate additional safety margin into the design, which often increases the cost of the reactor. Therefore basic nuclear data needs to be improved and this is accomplished through experimentation. Considering the high cost of nuclear experiments, it is desired to have an optimized experiment which will provide the data needed for uncertainty reduction such that a reactor design concept can meet its target accuracies or to allow savings to be realized by reducing the margin required due to uncertainty propagated from basic nuclear data. However, this optimization is coupled to the reactor design itself because with improved data the reactor concept can be re-optimized itself. It is thus desired to find the experiment that gives the best optimized reactor design. Methods are first established to model both the reactor concept and the experiment and to efficiently propagate the basic nuclear data uncertainty through these models to outputs. The representativity of the experiment

  5. A complexity basis for phenomenology: How information states at criticality offer a new approach to understanding experience of self, being and time.

    PubMed

    Hankey, Alex

    2015-12-01

    In the late 19th century Husserl studied our internal sense of time passing, maintaining that its deep connections into experience represent prima facie evidence for it as the basis for all investigations in the sciences: Phenomenology was born. Merleau-Ponty focused on perception pointing out that any theory of experience must accord with established aspects of biology i.e. be embodied. Recent analyses suggest that theories of experience require non-reductive, integrative information, together with a specific property connecting them to experience. Here we elucidate a new class of information states with just such properties found at the loci of control of complex biological systems, including nervous systems. Complexity biology concerns states satisfying self-organized criticality. Such states are located at critical instabilities, commonly observed in biological systems, and thought to maximize information diversity and processing, and hence to optimize regulation. Major results for biology follow: why organisms have unusually low entropies; and why they are not merely mechanical. Criticality states form singular self-observing systems, which reduce wave packets by processes of perfect self-observation associated with feedback gain g = 1. Analysis of their information properties leads to identification of a new kind of information state with high levels of internal coherence, and feedback loops integrated into their structure. The major idea presented here is that the integrated feedback loops are responsible for our 'sense of self', and also the feeling of continuity in our sense of time passing. Long-range internal correlations guarantee a unique kind of non-reductive, integrative information structure enabling such states to naturally support phenomenal experience. Being founded in complexity biology, they are 'embodied'; they also fulfill the statement that 'The self is a process', a singular process. High internal correlations and René Thom

  6. A complexity basis for phenomenology: How information states at criticality offer a new approach to understanding experience of self, being and time.

    PubMed

    Hankey, Alex

    2015-12-01

    In the late 19th century Husserl studied our internal sense of time passing, maintaining that its deep connections into experience represent prima facie evidence for it as the basis for all investigations in the sciences: Phenomenology was born. Merleau-Ponty focused on perception pointing out that any theory of experience must accord with established aspects of biology i.e. be embodied. Recent analyses suggest that theories of experience require non-reductive, integrative information, together with a specific property connecting them to experience. Here we elucidate a new class of information states with just such properties found at the loci of control of complex biological systems, including nervous systems. Complexity biology concerns states satisfying self-organized criticality. Such states are located at critical instabilities, commonly observed in biological systems, and thought to maximize information diversity and processing, and hence to optimize regulation. Major results for biology follow: why organisms have unusually low entropies; and why they are not merely mechanical. Criticality states form singular self-observing systems, which reduce wave packets by processes of perfect self-observation associated with feedback gain g = 1. Analysis of their information properties leads to identification of a new kind of information state with high levels of internal coherence, and feedback loops integrated into their structure. The major idea presented here is that the integrated feedback loops are responsible for our 'sense of self', and also the feeling of continuity in our sense of time passing. Long-range internal correlations guarantee a unique kind of non-reductive, integrative information structure enabling such states to naturally support phenomenal experience. Being founded in complexity biology, they are 'embodied'; they also fulfill the statement that 'The self is a process', a singular process. High internal correlations and René Thom

  7. Worldviews, Criticisms, and the Peer Circle: A Study of the Experiences of a Student Teacher in an Overseas School

    ERIC Educational Resources Information Center

    Karaman, A. Cendel; Tochon, Francois V.

    2010-01-01

    This article explores international student teaching (IST) within the narratives of a prospective language teacher from the midwestern region of the United States. With a focus on one participant, the case study highlights significant factors that relate to the IST experience in Ecuador. A corpus generated from verbal protocols collected over a…

  8. Conducting Multi-Generational Qualitative Research in Education: An Experiment in Grounded Theory. Black Studies and Critical Thinking. Volume 5

    ERIC Educational Resources Information Center

    Collins, Donald R.

    2011-01-01

    This book outlines a methodology for viewing multiple generations of African Americans, specifically those who were called or called themselves Negro, Colored, Black, or African American (NCBAA). Within this framework, African Americans of varying ages describe their lives and educational experiences, allowing researchers to address a variety of…

  9. Unpacking Your Study Abroad Experience: Critical Reflection for Workplace Competencies. Volume 1, Issue 1. CERI Research Brief 1-2008

    ERIC Educational Resources Information Center

    Gardner, Phil; Gross, Linda; Steglitz, Inge

    2008-01-01

    Colleges and universities are in competition to claim leadership in preparing students for a global world through participation in international experiences. Michigan State University (MSU) is often recognized as one of the leaders in study abroad, having woven the ethos of global education tightly into the core fabric of the university and…

  10. [Experience with knowledge development in food handlers with te implementation of Hazard Analysis Critical control points (HACCP) in a hospital food service].

    PubMed

    de Sousa, A A; de Salles, R K; Felipe, M R; Tosin, I

    1999-03-01

    The present article has as objective to describe the methodology of an experience of implantation of Hazard Analyses Critical Control Points (HACCP) with food handlers in a hospital food service establishment, inside of a conception of relationship and construction of knowledge. Meetings with the food handlers and nutritionists, with the objective of raising the difficulties poined for the sector and the work to be developed. The HACCP consisted of the evaluation of the operations, following the sequential steps recommended, looking itself to instruct the food handlers on the methods of the operations and its interpretations. The detected critical points, the measures of control, the criteria of correction and the monitoring have widely been argued, serving as didactic elements for the reconstruction of quality of the preparations. The discussions generated actions that were developed in short term, revealing the need of a more effective and continuous partnership for the new proposals. PMID:10412507

  11. [Experience with knowledge development in food handlers with te implementation of Hazard Analysis Critical control points (HACCP) in a hospital food service].

    PubMed

    de Sousa, A A; de Salles, R K; Felipe, M R; Tosin, I

    1999-03-01

    The present article has as objective to describe the methodology of an experience of implantation of Hazard Analyses Critical Control Points (HACCP) with food handlers in a hospital food service establishment, inside of a conception of relationship and construction of knowledge. Meetings with the food handlers and nutritionists, with the objective of raising the difficulties poined for the sector and the work to be developed. The HACCP consisted of the evaluation of the operations, following the sequential steps recommended, looking itself to instruct the food handlers on the methods of the operations and its interpretations. The detected critical points, the measures of control, the criteria of correction and the monitoring have widely been argued, serving as didactic elements for the reconstruction of quality of the preparations. The discussions generated actions that were developed in short term, revealing the need of a more effective and continuous partnership for the new proposals.

  12. The CIV processes in the CRIT experiments. [reconciliation of Critical Ionization Velocity hypothesis with sounding rocket observations

    NASA Technical Reports Server (NTRS)

    Papadopoulos, K.

    1992-01-01

    A qualitative analysis is conducted to reconcile the experimental data from critical ionization velocity (CIV) studies with CIV theories. The experimental data are reviewed demonstrating that: (1) the wave frequency is variable and low; (2) the wave polarization is almost isotropic; (3) electron energization is not easily reconciled with the observed wave spectrum; and (4) ambient electron density plays a role in determining CIV triggering conditions. Analytical treatment is given to the dispersion relation of the lower hybrid wave (LWH) instability driven by the streaming of an ion beam generated by the interaction of the neutral cloud with the ambient atmosphere. By incorporating the LWH instabilities of strong turbulence and finite-size effects into theoretical CIV relationships, the observations can be interpreted. The issues raised by the experimental data are understood within the context of a hypothesis of backward propagating nonlinearly collapsing wavepackets.

  13. Growth and Expansion of the International Criticality Safety Benchmark Evaluation Project and the Newly Organized International Reactor Physics Experiment Evaluation Project

    SciTech Connect

    J. Blair Briggs; Lori Scott; Yolanda Rugama; Enrico Satori

    2007-05-01

    Since ICNC 2003, the International Criticality Safety Benchmark Evaluation Project (ICSBEP) has continued to expand its efforts and broaden its scope. Criticality-alarm / shielding type benchmarks and fundamental physics measurements that are relevant to criticality safety applications are not only included in the scope of the project, but benchmark data are also included in the latest version of the handbook. A considerable number of improvements have been made to the searchable database, DICE and the criticality-alarm / shielding benchmarks and fundamental physics measurements have been included in the database. There were 12 countries participating on the ICSBEP in 2003. That number has increased to 18 with recent contributions of data and/or resources from Brazil, Czech Republic, Poland, India, Canada, and China. South Africa, Germany, Argentina, and Australia have been invited to participate. Since ICNC 2003, the contents of the “International Handbook of Evaluated Criticality Safety Benchmark Experiments” have increased from 350 evaluations (28,000 pages) containing benchmark specifications for 3070 critical or subcritical configurations to 442 evaluations (over 38,000 pages) containing benchmark specifications for 3957 critical or subcritical configurations, 23 criticality-alarm-placement / shielding configurations with multiple dose points for each, and 20 configurations that have been categorized as fundamental physics measurements that are relevant to criticality safety applications in the 2006 Edition of the ICSBEP Handbook. Approximately 30 new evaluations and 250 additional configurations are expected to be added to the 2007 Edition of the Handbook. Since ICNC 2003, a reactor physics counterpart to the ICSBEP, The International Reactor Physics Experiment Evaluation Project (IRPhEP) was initiated. Beginning in 1999, the IRPhEP was conducted as a pilot activity by the by the Organization of Economic Cooperation and Development (OECD) Nuclear Energy

  14. Encouraging PV Adoption in New Market-Rate ResidentialConstruction: A Critical Review of Program Experiences to Date

    SciTech Connect

    Barbose, Galen; Wiser, Ryan; Bolinger, Mark

    2006-04-24

    In this paper, we review experiences with programs to support the deployment of photovoltaics (PV) in new, market-rate homes, drawing upon interviews with program managers around the country, project data, and publicly-available documentation on program design, impacts, and experiences. We focus on state clean energy funds, which have been established in 14 U.S. states to build markets for clean energy resources, as well as a select number of other state or local organizations whose activities are particularly noteworthy. We describe the types of programs implemented and their impacts to date, and discuss key issues and lessons learned for initiatives aimed at growing the new home market for PV.

  15. Cultural competence in psychosocial and psychiatric care: a critical perspective with reference to research and clinical experiences in California, US and in Germany.

    PubMed

    Schultz, Dagmar

    2004-01-01

    The impact of culture and ethnicity on the diagnosis and treatment of patients with mental disorders has been of growing interest and concern to professionals in the United States and also in Germany. This contribution intends to give an overview of key aspects regarding competence in intercultural situations using research and clinical experiences from the United States and from Germany. The issue of racism and discrimination as contributing factors in the development of mental disorders will be critically examined from a US and a German perspective.

  16. Cultural competence in psychosocial and psychiatric care: a critical perspective with reference to research and clinical experiences in California, US and in Germany.

    PubMed

    Schultz, Dagmar

    2004-01-01

    The impact of culture and ethnicity on the diagnosis and treatment of patients with mental disorders has been of growing interest and concern to professionals in the United States and also in Germany. This contribution intends to give an overview of key aspects regarding competence in intercultural situations using research and clinical experiences from the United States and from Germany. The issue of racism and discrimination as contributing factors in the development of mental disorders will be critically examined from a US and a German perspective. PMID:15774394

  17. Waste characterization at Los Alamos National Laboratory

    SciTech Connect

    Corpion, J.C.; Grieggs, A.R.

    1991-01-01

    Most industries generate limited types of solid wastes of a result of their manufacturing processes. The Los Alamos National Laboratory (LANL), a research and development facility, generates a large variety of solid wastes, some exotic. Over 50,000 distinct waste streams are currently generated in the 43 square mile area defining LANL. These wastes include refuse, medical, infectious, hazardous, radioactive, and mixed wastes. LANL is subject to federal and State oversight on matters concerning management of solid wastes. In order to assure regulatory agencies such as the New Mexico Environment Department (NMED) and the US Environmental Protection Agency (EPA) that the Laboratory is properly managing and disposing all solid wastes. LANL has undertaken an extensive waste characterization program to identify sources and ultimate disposition of all solid wastes. Given the number of solid waste streams expected, LANL has taken a two-pronged approach to characterizing wastes: (a) physical identification of all sources of solid wastes including interviews with waste generators; and (b) characterization of wastes from the point of generation. The former approach consists of canvassing all structures within the LANL complex, interviewing waste generators, and identifying sources of waste generation. Data gathered by these interviews are compiled in a database in order to identify the types and rates of waste generation and correct mismanagement of wastes identified during the interviews. The latter approach consists of characterizing all solid wastes which are controlled administratively or subject to stricter controls than municipal solid wastes (i.e., infectious, hazardous, radioactive, and mixed wastes). This characterization forms the basis by which LANL will manage solid waste in accordance to NMED/EPA regulations and US Department of Energy Orders. 8 refs., 3 figs.

  18. Nuclear criticality safety: 5-day training course

    SciTech Connect

    Schlesser, J.A.

    1992-11-01

    This compilation of notes is presented as a source reference for the criticality safety course. It represents the contributions of many people, particularly Tom McLaughlin, the course`s primary instructor. At the completion of this training course, the attendee will: be able to define terms commonly used in nuclear criticality safety; be able to appreciate the fundamentals of nuclear criticality safety; be able to identify factors which affect nuclear criticality safety; be able to identify examples of criticality controls as used at Los Alamos; be able to identify examples of circumstances present during criticality accidents; be able to identify examples of computer codes used by the nuclear criticality safety specialist; be able to identify examples of safety consciousness required in nuclear criticality safety.

  19. Nuclear criticality safety: 5-day training course

    SciTech Connect

    Schlesser, J.A.

    1992-11-01

    This compilation of notes is presented as a source reference for the criticality safety course. It represents the contributions of many people, particularly Tom McLaughlin, the course's primary instructor. At the completion of this training course, the attendee will: be able to define terms commonly used in nuclear criticality safety; be able to appreciate the fundamentals of nuclear criticality safety; be able to identify factors which affect nuclear criticality safety; be able to identify examples of criticality controls as used at Los Alamos; be able to identify examples of circumstances present during criticality accidents; be able to identify examples of computer codes used by the nuclear criticality safety specialist; be able to identify examples of safety consciousness required in nuclear criticality safety.

  20. Group Dynamics as a Critical Component of Successful Space Exploration: Conceptual Theory and Insights from the Biosphere 2 Closure Experiment

    NASA Astrophysics Data System (ADS)

    Nelson, Mark; Allen, John P.

    As space exploration and eventually habitation achieves longer durations, successfully managing group dynamics of small, physically isolated groups will become vital. The paper summarizes important underlying research and conceptual theory and how these manifested in a well-documented example: the closure experiments of Biosphere 2. Key research breakthroughs in discerning the operation of small human groups comes from the pioneering work of W.R. Bion. He discovered two competing modalities of behavior. The first is the “task-oriented” or work group governed by shared acceptance of goals, reality-thinking in relation to time, resources and rational, and intelligent management of challenges presented. The opposing, usually unconscious, modality is what Bion called the “basic-assumption” group and alternates between three “group animal” groups: dependency/kill the leader; fight/flight and pairing. If not dealt with, these dynamics work to undermine and defeat the conscious task group’s goal achievement. The paper discusses crew training and selection, various approaches to structuring the work and hierarchy of the group, the importance of contact with a larger population through electronic communication and dealing with the “us-them” syndrome frequently observed between crew and Mission Control. The experience of the first two year closure of Biosphere 2 is drawn on in new ways to illustrate vicissitudes and management of group dynamics especially as both the inside team of biospherians and key members of Mission Control had training in working with group dynamics. Insights from that experience may help mission planning so that future groups in space cope successfully with inherent group dynamics challenges that arise.

  1. Using formal specification in the Guidance and Control Software (GCS) experiment. Formal design and verification technology for life critical systems

    NASA Technical Reports Server (NTRS)

    Weber, Doug; Jamsek, Damir

    1994-01-01

    The goal of this task was to investigate how formal methods could be incorporated into a software engineering process for flight-control systems under DO-178B and to demonstrate that process by developing a formal specification for NASA's Guidance and Controls Software (GCS) Experiment. GCS is software to control the descent of a spacecraft onto a planet's surface. The GCS example is simplified from a real example spacecraft, but exhibits the characteristics of realistic spacecraft control software. The formal specification is written in Larch.

  2. Next generation of elevated [CO2] experiments with crops: A critical investment for feeding the future world

    SciTech Connect

    Ainsworth, Elizabeth A.; Norby, Richard J

    2008-01-01

    Rising demand for grain crops and an expanding biofuel industry are vastly increasing pressure to maximize productivity on agricultural land. Rising atmospheric [CO2] is increasing global temperature and altering precipitation patterns, which will challenge agricultural productivity in the future. Yet, rising [CO2] also provides a unique opportunity to markedly increase the productivity of C3 crops, but the average yield stimulation observed to date is well below the potential theoretical gains. This suggests there is significant room for improving productivity. There are tens of thousands of lines of wheat, rice, soybean and other crops available, but only a fraction of these have been tested for CO2 responsiveness in a production environment. Yield is a complex phenotypic trait determined by the interactions of a genotype with the environment. Selection of promising genotypes and characterization of physiological mechanisms will only be effective if the crop improvement and systems biology approaches are closely linked to actual production environments, i.e., on the farm within the major growing regions. Free Air Carbon dioxide Enrichment (FACE) experiments can provide the platform upon which to conduct genetic screening as well as to elucidate the inheritance and mechanisms that underlie cultivar differences in productivity under elevated [CO2]. We propose a new generation of large scale, low-cost per unit area, FACE facilities and experiments to identify the most CO2-responsive genotypes and provide starting lines for future breeding programs. This is necessary if we are to realize the potential yield gains n the future.

  3. Limiting intensive care therapy in dying critically Ill patients: Experience from a tertiary care center in United Arab Emirates

    PubMed Central

    Masood, Ur Rahman; Said, Abuhasna; Faris, Chedid; Al Mussady, Mousab; Al Jundi, Amer

    2013-01-01

    Background: Limitations of life-support interventions, by either withholding or withdrawing support, are integrated parts of intensive care unit (ICU) activities and are ethically acceptable. The end-of-life legal aspects and practices in United Arab Emirates ICUs are rarely mentioned in the medical literature. The objective of this study was to examine the current practice of limiting futile life-sustaining therapies in our ICU, modalities for implementing of these decisions, and documentations in dying critically ill patients. Materials and Methods: This was a retrospective observational study conducted at our ICU. We studied all ICU patients who died from September 2008 to February 2009. Patients’ baseline demo-graphics, past medical problems, diagnosis on admission to ICU, and decision to withhold, withdraw and their modalities were collected. Methods: This was a retrospective observational study conducted at our ICU. We studied all ICU patients who died from September 2008 to February 2009. Patients’ baseline demo-graphics, past medical problems, diagnosis on admission to ICU, and decision to withhold, withdraw and their modalities were collected. Results: The electronic medical records of 67 patients were reviewed. The commonest method of limiting therapy was no escalation 53.6%. Interventions were withheld in 41.5%. “Do not resuscitate” order was documented in only 16.3%. The commonest method of documenting limitation of therapy was discussion with the family and documenting the prognosis and futility of additional therapy (73.3%). Patients who died early (<48 hrs) compared to patients who died late (>48 hrs) of ICU admission received terminal cardiopulmonary resuscitation more frequently (P < 0.007), had less frequent prognosis documentation (P < 0.009), and had more vasopressors administered (P < 0.006). Conclusion: Withholding therapy after discussion with the family was the preferred mode of limiting therapy in a dying patient. PMID:24404458

  4. Methodology of full-core Monte Carlo calculations with leakage parameter evaluations for benchmark critical experiment analysis

    NASA Astrophysics Data System (ADS)

    Sboev, A. G.; Ilyashenko, A. S.; Vetrova, O. A.

    1997-02-01

    The method of bucking evaluation, realized in the MOnte Carlo code MCS, is described. This method was applied for calculational analysis of well known light water experiments TRX-1 and TRX-2. The analysis of this comparison shows, that there is no coincidence between Monte Carlo calculations, obtained by different ways: the MCS calculations with given experimental bucklings; the MCS calculations with given bucklings evaluated on base of full core MCS direct simulations; the full core MCNP and MCS direct simulations; the MCNP and MCS calculations, where the results of cell calculations are corrected by the coefficients taking into the account the leakage from the core. Also the buckling values evaluated by full core MCS calculations have differed from experimental ones, especially in the case of TRX-1, when this difference has corresponded to 0.5 percent increase of Keff value.

  5. Experience of sexual violence among women in HIV discordant unions after voluntary HIV counselling and testing: a qualitative critical incident study in Uganda.

    PubMed

    Emusu, Donath; Ivankova, Nataliya; Jolly, Pauline; Kirby, Russell; Foushee, Herman; Wabwire-Mangen, Fred; Katongole, Drake; Ehiri, John

    2009-11-01

    HIV-serodiscordant relationships are those in which one partner is infected with HIV while the other is not. We investigated experiences of sexual violence among women in HIV discordant unions attending HIV post-test club services in Uganda. A volunteer sample of 26 women from three AIDS Information Centres in Uganda who reported having experienced sexual violence in a larger epidemiological study were interviewed, using the qualitative critical incident technique. Data were analysed using TEXTPACK, a software application for computer-assisted content analysis. Incidents of sexual violence narrated by the women included use of physical force and verbal threats. Overall, four themes that characterise the women's experience of sexual violence emerged from the analysis: knowledge of HIV test results, prevalence of sexual violence, vulnerability and proprietary views and reactions to sexual violence. Alcohol abuse by the male partners was an important factor in the experience of sexual violence among the women. Their experiences evoked different reactions and feelings, including concern over the need to have children, fear of infection, desire to separate from their spouses/partners, helplessness, anger and suicidal tendencies. HIV counselling and testing centres should be supported with the capacity to address issues related to sexual violence for couples who are HIV discordant.

  6. 1993 Northern goshawk inventory on portions of Los Alamos National Laboratory, Los Alamos, NM. Final report

    SciTech Connect

    Sinton, D.T.; Kennedy, P.L.

    1994-06-01

    Northern goshawks (Accipiter gentilis) (hereafter referred to as goshawk) is a large forest dwelling hawk. Goshawks may be declining in population and reproduction in the southwestern United States. Reasons for the possible decline in goshawk populations include timber harvesting resulting in the loss of nesting habitat, toxic chemicals, and the effects of drought, fire, and disease. Thus, there is a need to determine their population status and assess impacts of management activities in potential goshawk habitat. Inventory for the goshawk was conducted on 2,254 ha of Los Alamos National Laboratory (LANL) to determine the presence of nesting goshawks on LANL lands. This information can be incorporated into LANL`s environmental management program. The inventory was conducted by Colorado State University personnel from May 12 to July 30, 1993. This report summarizes the results of this inventory.

  7. Integrated review software advances at Los Alamos

    SciTech Connect

    Klosterbuer, S. F.; Michel, K. D.; Betts, S. E.; Determan, J. C.; Longo, J. F.; Parker, R. F.; Pelowitz, D. G.; Rothrock, R. B.; Schneider, C. M.; Nordquist, H. M.

    2004-01-01

    Since 1988, Los Alamos National Laboratory (LANL) has been developing software for unattended monitoring systems. These systems are composed of three categories of software: acquisition, collection and review. The data acquisition software is contained in modular instrumentation distributed throughout facilities to continuously acquire data from devices ranging from radiation detectors to cameras to binary switches. The data collection software runs on computers connected to the instruments and offloads and stores the acquired data. The review software enables the end user to quickly and easily examine the data collected from these different systems and compare the results to declared operator activities. This paper addresses the review software. The original standalone review software processed only radiation data. This software was expanded to include new programs (tools) to display and correlate video and operator declarations and added an interface to the standard neutron coincidence counter analysis program. This expanded review software containing multiple review tools is referred to collectively as the Integrated Review Software (IRS). The IRS continues to expand and evolve. Two primary IRS developments will be described in this paper. First, the IRS was expanded to include review tools to display and analyze new data types. Position Review was developed to display Global Positioning System (GPS) location data to aid in tracking radiation movements. Isotopic Review is being developed to provide a link to the standard gamma isotopic analysis software. In addition significant enhancements are being added to the existing review tools such as Operator Review, Radiation Review and Digital Video Review. A second IRS development is to produce standardized components with published interfaces enabling other parties to produce custom components that plug into review software. It is anticipated that there will be four primary types of components that could be

  8. Water Supply at Los Alamos 1998-2001

    SciTech Connect

    Richard J. Koch; David B. Rogers

    2003-03-01

    For the period 1998 through 2001, the total water used at Los Alamos from all sources ranged from 1325 million gallons (Mg) in 1999 to 1515 Mg in 2000. Groundwater production ranged from 1323 Mg in 1999 to 1506 Mg in 2000 from the Guaje, Pajarito, and Otowi fields. Nonpotable surface water used from Los Alamos reservoir ranged from zero gallons in 2001 to 9.3 Mg in 2000. For years 1998 through 2001, over 99% of all water used at Los Alamos was groundwater. Water use by Los Alamos National Laboratory (LANL) between 1998 and 2001 ranged from 379 Mg in 2000 to 461 Mg in 1998. The LANL water use in 2001 was 393 Mg or 27% of the total water use at Los Alamos. Water use by Los Alamos County ranged from 872 Mg in 1999 to 1137 Mg in 2000, and averaged 1006 Mg/yr. Four new replacement wells in the Guaje field (G-2A, G-3A, G-4A, and G-5A) were drilled in 1998 and began production in 1999; with existing well G-1A, the Guaje field currently has five producing wells. Five of the old Guaje wells (G-1, G-2, G-4, G-5, and G-6) were plugged and abandoned in 1999, and one well (G-3) was abandoned but remains as an observation well for the Guaje field. The long-term water level observations in production and observation (test) wells at Los Alamos are consistent with the formation of a cone of depression in response to water production. The water level decline is gradual and at most has been about 0.7 to 2 ft per year for production wells and from 0.4 to 0.9 ft/yr for observation (test) wells. The largest water level declines have been in the Guaje field where nonpumping water levels were about 91 ft lower in 2001 than in 1951. The initial water levels of the Guaje replacement wells were 32 to 57 ft lower than the initial water levels of adjacent original Guaje wells. When production wells are taken off-line for pump replacement or repair, water levels have returned to within about 25 ft of initial static levels within 6 to 12 months. Thus, the water-level trends suggest no adverse

  9. Publications of Los Alamos research, 1977-1981

    SciTech Connect

    Sheridan, C.J.; Garcia, C.A.

    1983-03-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1977-1981. Papers published in those years are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

  10. Water supply at Los Alamos during 1993. Progress report

    SciTech Connect

    Purtymun, W.D.; Stoker, A.K.; McLin, S.G.; Maes, M.N.; Glasco, T.A.

    1995-10-01

    This report summarizes production and aquifer conditions for water wells in the Guaje, Pajarito, and Otowi Well Fields. These wells supplied all of the potable water used for municipal and some industrial purposes in Los Alamos County and the Los Alamos National Laboratory during 1993. The wells in the Los Alamos Well Field were transferred to San Ildefonso Pueblo in 1992. Four of the wells in the Los Alamos Well Field were plugged in 1993. One of the two new wells in the Otowi Well Field became operational in 1993. The spring gallery in Water Canyon supplied nonpotable water for industrial use, while surface water from the Los Alamos Reservoir was diverted for irrigation. In 1993 no water was used from the Guaje Reservoir. Due to the maintenance and operating cost of diverting water from the reservoirs, it is not economically feasible to continue their use for irrigation. This report fulfills some of the requirements of the Los Alamos Groundwater Protection Management Program by documenting use of the groundwater for water supply and providing information hydrologic characteristics of the main aquifer. This report is a joint effort between the Laboratory Water Quality and Hydrology Group and the Utilities Department of Johnson Controls World Services Inc. (JCI). The purpose of this report is to ensure a continuing historical record and to provide guidance for management of water resources in long-range planning for the water supply system. We have issued one summary report for the period of 1947 to 1971 and 22 annual reports that contain the results of our studies of these water supplies. An additional report summarized the hydrology of the main aquifer with reference to future development of groundwater supplies. A report was issued in 1988 that examined the status of wells and future water supply.

  11. Nuclear criticality safety: 3-day training course

    SciTech Connect

    Schlesser, J.A.

    1992-11-01

    This compilation of notes is presented as a source reference for the criticality safety course. It represents the contributions of many people, particularly Tom McLaughlin, the course's primary instructor. At the completion of this training course, the attendee will: (1) be able to define terms commonly used in nuclear criticality safety; (2) be able to appreciate the fundamentals of nuclear criticality safety; (3) be able to identify factors which affect nuclear criticality safety; (4) be able to identify examples of criticality controls as used at Los Alamos; (5) be able to identify examples of circumstances present during criticality accidents; (6) be able to identify examples of safety consciousness required in nuclear criticality safety.

  12. Nuclear criticality safety: 3-day training course

    SciTech Connect

    Schlesser, J.A.

    1992-11-01

    This compilation of notes is presented as a source reference for the criticality safety course. It represents the contributions of many people, particularly Tom McLaughlin, the course`s primary instructor. At the completion of this training course, the attendee will: (1) be able to define terms commonly used in nuclear criticality safety; (2) be able to appreciate the fundamentals of nuclear criticality safety; (3) be able to identify factors which affect nuclear criticality safety; (4) be able to identify examples of criticality controls as used at Los Alamos; (5) be able to identify examples of circumstances present during criticality accidents; (6) be able to identify examples of safety consciousness required in nuclear criticality safety.

  13. ZERT Final Scientific Report Los Alamos National Laboratory

    SciTech Connect

    Pawar, Rajesh J.

    2011-01-01

    Los Alamos National Laboratory's (LANL) activities for the Center for Zero Emission Research and Technology (ZERT) have fallen into three broad research areas: (1) How do you reduce uncertainty in assuring prior to operation that an engineered geologic site will meet a specific performance goal (e.g., <0.01% leak per year)? (2) What are key monitoring needs for verifying that an engineered geologic site is meeting a performance goal? (3) What are potential vulnerabilities for breeches in containment of CO{sub 2}, and how could they be mitigated either prior to operation or in the event that a threshold is exceeded? We have utilized LANL's multi-disciplinary expertise and an integrated approach combining laboratory experiments, field observations and numerical simulations to address various research issues related to above-mentioned areas. While there have been a number of major milestones achieved as described in past quarterly reports, two of the major accomplishments resulting from LANL's efforts include: (1) Development of the CO{sub 2}-PENS systems framework for long-term performance analysis of geologic CO{sub 2} sequestration sites. CO{sub 2}-PENS is first-ever systems analysis tool designed for assessment of CO{sub 2} sequestration sites. (2) One of the few field studies to-date focused on understanding impact of CO{sub 2} leakage on shallow groundwater chemistry. Two major conclusions of the study are as follows: the impact of co-contaminants transported with deeper brine on shallow groundwater quality is likely to be much larger than that of the CO{sub 2} and CO{sub 2}-induced geochemical reactions and in certain geochemical environment the reactivity of pure CO{sub 2} will not be sufficient to mobilize metals beyond background levels.

  14. The development of the atomic bomb, Los Alamos

    SciTech Connect

    Seidel, R.W.

    1993-11-01

    The historical presentation begins with details of the selection of Los Alamos as the site of the Army installation. Wartime efforts of the Army Corps of Engineers, and scientists to include the leader of Los Alamos, Robert Oppenheimer are presented. The layout and construction of the facilities are discussed. The monumental design requirements of the bombs are discussed, including but not limited to the utilization of the second choice implosion method of detonation, and the production of bomb-grade nuclear explosives. The paper ends with a philosophical discussion on the use of nuclear weapons.

  15. Fifty-one years of Los Alamos Spacecraft

    SciTech Connect

    Fenimore, Edward E.

    2014-09-04

    From 1963 to 2014, the Los Alamos National Laboratory was involved in at least 233 spacecraft. There are probably only one or two institutions in the world that have been involved in so many spacecraft. Los Alamos space exploration started with the Vela satellites for nuclear test detection, but soon expanded to ionospheric research (mostly barium releases), radioisotope thermoelectric generators, solar physics, solar wind, magnetospheres, astrophysics, national security, planetary physics, earth resources, radio propagation in the ionosphere, and cubesats. Here, we present a list of the spacecraft, their purpose, and their launch dates for use during RocketFest

  16. A physicists guide to The Los Alamos Primer

    NASA Astrophysics Data System (ADS)

    Reed, B. Cameron

    2016-11-01

    In April 1943, a group of scientists at the newly established Los Alamos Laboratory were given a series of lectures by Robert Serber on what was then known of the physics and engineering issues involved in developing fission bombs. Serber’s lectures were recorded in a 24 page report titled The Los Alamos Primer, which was subsequently declassified and published in book form. This paper describes the background to the Primer and analyzes the physics contained in its 22 sections. The motivation for this paper is to provide a firm foundation of the background and contents of the Primer for physicists interested in the Manhattan Project and nuclear weapons.

  17. Contributions of chemistry in early day Los Alamos

    SciTech Connect

    Penneman, R.A.; Meade, R.A.

    1990-01-01

    During 1943--1945, the premier physics laboratory in the world was at Los Alamos, but chemistry contributions were vital. Major chemical impacts on the success of the Los Alamos wartime mission included electrochemistry, which found the true melting point of plutonium metal to be hundreds of degrees lower than anticipated. This discovery had profound simplifying effects regarding crucibles to contain molten plutonium and on its production. Other significant chemical contributions involved constant purification of plutonium for reuse, producing carrier-free gamma sources at unprecedented kilo-curie levels, and high polonium work. 8 refs.

  18. Needs assessment for fire department services and resources for the Los Alamos National Laboratory, Los Alamos, New Mexico. Final report

    SciTech Connect

    1995-11-15

    This report has been developed in response to a request from the Los Alamos National Laboratory (LANL) to evaluate the need for fire department services so as to enable the Laboratory to plan effective fire protection and thereby: meet LANL`s regulatory and contractual obligations; interface with the Department of Energy (DOE) and other agencies on matters relating to fire and emergency services; and ensure appropriate protection of the community and environment. This study is an outgrowth of the 1993 Fire Department Needs Assessment (prepared for DOE) but is developed from the LANL perspective. Input has been received from cognizant and responsible representatives at LANL, DOE, Los Alamos County (LAC) and the Los Alamos Fire Department (LAFD).

  19. Implementing the CASPiE course-based research experience at the United States Military Academy: Affective responses and effects on critical thinking

    NASA Astrophysics Data System (ADS)

    Chase, Anthony Michael

    The Center for Authentic Science Practices in Education (CASPiE) pioneered a course-based research experience approach to teaching chemistry laboratory courses. The method had previously been studied in a variety of institutional settings. Recently, the United States Military Academy at West Point decided to develop CASPiE-style modules for the introductory honors chemistry course. This research setting presents clean experimental-control comparisons and a group of faculty who were completely new to the method. Equipping students with authentic research experiences early in their education is important regardless of the institution. However, cadets at a military academy must make decisions relatively early (the outset of their second year) as to what their career trajectory will be as eventual officers. In the new CASPiE-based experience, cadets are given the opportunity to select from one of three different modules (analytical chemistry, toxicology, and chemical engineering) in which to participate during the course. These three modules represent subsections of an overall Army waste-to-energy research project. Cadets generate unique hypotheses, real data, and research posters towards the advancement of the project. Posters are then presented in a session. that includes an audience of project stakeholders, course instructors, and other academy faculty and staff. Here, I will present my research methods, evaluative procedures, and findings in the affective domain, critical thinking, and laboratory content comprehension.

  20. A survey of macromycete diversity at Los Alamos National Laboratory, Bandelier National Monument, and Los Alamos County; A preliminary report

    SciTech Connect

    Jarmie, N.; Rogers, F.J.

    1997-11-01

    The authors have completed a 5-year survey (1991--1995) of macromycetes found in Los Alamos County, Los Alamos National Laboratory, and Bandelier National Monument. The authors have compiled a database of 1,048 collections, their characteristics, and identifications. The database represents 123 (98%) genera and 175 (73%) species reliably identified. Issues of habitat loss, species extinction, and ecological relationships are addressed, and comparisons with other surveys are made. With this baseline information and modeling of this baseline data, one can begin to understand more about the fungal flora of the area.