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Sample records for preliminary neutronic evaluation

  1. Preliminary Evaluation and Uncertainty Quantification of the Prompt Fission Neutron Spectrum of {sup 239}Pu

    SciTech Connect

    Neudecker, D.; Talou, P.; Taddeucci, T.N.; Haight, R.C.; Kawano, T.; Lee, H.Y.; Smith, D.L.; Capote, R.; Rising, M.E.; White, M.C.

    2015-01-15

    Low evaluated uncertainties were obtained in a previous evaluation of the {sup 239}Pu prompt fission neutron spectrum and associated covariances for incident neutrons of 0.5 MeV, which were enlarged a-posteriori before being incorporated into ENDF/B-VII.1. These low evaluated uncertainties triggered an in-depth study and improved estimate of experimental as well as model uncertainties. Here, we will summarize these efforts and show that the improved estimate of experimental and model uncertainties leads to corresponding evaluated uncertainties in good agreement with uncertainties obtained in a statistical analysis based primarily on experimental information.

  2. Preliminary Evaluation and Uncertainty Quantification of the Prompt Fission Neutron Spectrum of 239Pu

    NASA Astrophysics Data System (ADS)

    Neudecker, D.; Talou, P.; Taddeucci, T. N.; Haight, R. C.; Kawano, T.; Lee, H. Y.; Smith, D. L.; Capote, R.; Rising, M. E.; White, M. C.

    2015-01-01

    Low evaluated uncertainties were obtained in a previous evaluation of the 239Pu prompt fission neutron spectrum and associated covariances for incident neutrons of 0.5 MeV, which were enlarged a-posteriori before being incorporated into ENDF/B-VII.1. These low evaluated uncertainties triggered an in-depth study and improved estimate of experimental as well as model uncertainties. Here, we will summarize these efforts and show that the improved estimate of experimental and model uncertainties leads to corresponding evaluated uncertainties in good agreement with uncertainties obtained in a statistical analysis based primarily on experimental information.

  3. A preliminary neutronic evaluation of high temperature engineering test reactor using the SCALE6 code

    NASA Astrophysics Data System (ADS)

    Tanure, L. P. A. R.; Sousa, R. V.; Costa, D. F.; Cardoso, F.; Veloso, M. A. F.; Pereira, C.

    2014-02-01

    Neutronic parameters of some fourth generation nuclear reactors have been investigated at the Departamento de Engenharia Nuclear/UFMG. Previous studies show the possibility to increase the transmutation capabilities of these fourth generation systems to achieve significant reduction concerning transuranic elements in spent fuel. To validate the studies, a benchmark on core physics analysis, related to initial testing of the High Temperature Engineering Test Reactor and provided by International Atomic Energy Agency (IAEA) was simulated using the Standardized Computer Analysis for Licensing Evaluation (SCALE). The CSAS6/KENO-VI control sequence and the 44-group ENDF/B-V 0 cross-section neutron library were used to evaluate the keff (effective multiplication factor) and the result presents good agreement with experimental value.

  4. Preliminary evaluation of neutron capture cross sections for /sup 144/Sm, /sup 145/Sm and /sup 145/Pm

    SciTech Connect

    Gardner, D.G.; Gardner, M.A.

    1986-02-13

    We have made preliminary neutron-capture cross-section calculations of the Hauser-Feshbach type for the isotopes /sup 144/Sm, /sup 145/Sm, and /sup 145/Pm to investigate the production of radioactive /sup 145/Pm by neutron capture on the stable isotope /sup 144/Sm. The calculations were made for incident neutron energies from 2.5 MeV to about 1/sup -4/ or 10/sup -5/ MeV, wherever the first unbound resonance was estimated to occur in each case. At that energy, the calculated value was reduced by a somewhat arbitrary factor, and the excitation function extended down to thermal energy using a (E/sub n/)/sup -1/2/ energy dependence. Since very large uncertainties are associated with the position and magnitude of the first unbound resonance and the subsequent extrapolation back to thermal energy, the cross sections in this low-energy region should not be considered more accurate than +- a factor of 10. For incident neutron energies above each step, the calculations represent an average through the separated and overlapping resonance regions and may be accurate to better than +- a factor of 2. 18 refs., 7 figs., 5 tabs.

  5. A preliminary neutron crystallographic study of thaumatin

    SciTech Connect

    Teixeira, Susana C. M.; Blakeley, Matthew P.; Leal, Ricardo M. F.; Mitchell, Edward P.; Forsyth, V. Trevor

    2008-05-01

    Preliminary neutron crystallographic data from the sweet protein thaumatin have been recorded using the LADI-III diffractometer at the Institut Laue Langevin (ILL). The results illustrate the feasibility of a full neutron structural analysis aimed at further understanding the molecular basis of the perception of sweet taste. Such an analysis will exploit the use of perdeuterated thaumatin. A preliminary neutron crystallographic study of the sweet protein thaumatin is presented. Large hydrogenated crystals were prepared in deuterated crystallization buffer using the gel-acupuncture method. Data were collected to a resolution of 2 Å on the LADI-III diffractometer at the Institut Laue Langevin (ILL). The results demonstrate the feasibility of a full neutron crystallographic analysis of this structure aimed at providing relevant information on the location of H atoms, the distribution of charge on the protein surface and localized water in the structure. This information will be of interest for understanding the specificity of thaumatin–receptor interactions and will contribute to further understanding of the molecular mechanisms underlying the perception of taste.

  6. Preliminary evaluation of cavitation-erosion resistance of Ti-alloys in mercury for the Spallation Neutron Source

    NASA Astrophysics Data System (ADS)

    Pawel, S. J.; Mansur, L. K.

    2010-03-01

    A number of Ti-based alloys in both the mill-annealed and 20% cold-worked conditions were subjected to sonication conditions in Hg using a vibratory horn to assess relative cavitation-erosion resistance. Weight loss as a function of exposure time decreased monotonically with increasing hardness for all alloys/conditions examined, with Ti-6Al-4V (Grade 5) and Ti-6Al-2Sn-4Zr-2Mo yielding the best resistance to cavitation-erosion as evidenced by low weight losses and little or no tendency to form pits on the exposed surface. Unalloyed Ti (Grade 4) and Ti-0.12Pd (Grade 7) exhibited greater weight losses by a factor of about two and about five, respectively, with Ti-0.12Pd particularly prone to pitting development. The mean erosion rates of the best two Ti-alloys examined were about a factor of three higher than identically tested 316LN stainless steel following a low temperature carburizing treatment, but this difference is considered minor given that the rate for both materials is very low/manageable and represents a through-thickness property for the Ti-alloys. A nitriding surface treatment was also evaluated as a potential method to further increase the cavitation-erosion resistance of these alloys in Hg, but the selected treatment proved largely ineffective as measured by rapid weight loss. Recommendations for further work to evaluate the efficacy of Ti-based alloys for use in high-powered targets for the Spallation Neutron Source are given.

  7. Preliminary Evaluation of Cavitation-Erosion Resistance of Ti-Alloys in Mercury for the Spallation Neutron Source

    SciTech Connect

    Pawel, Steven J; Mansur, Louis K

    2010-01-01

    A number of Ti-based alloys in both the mill-annealed and 20% cold-worked conditions were subjected to sonication conditions in Hg using a vibratory horn to assess relative cavitation-erosion resistance. Weight loss as a function of exposure time was roughly proportional to hardness for all alloys/conditions examined, with Ti-6Al-4V (Ti-Grade 5) and Ti-6Al-2Sn-4Zr-2Mo yielding the best resistance to cavitation-erosion as evidenced by low weight losses and little or no tendency to form pits on the exposed surface. Unalloyed Ti (Ti-Grade 4) and Ti-0.12Pd (Ti-Grade 7) exhibited greater weight losses by a factor or about two and about five, respectively, with Ti-0.12Pd particularly prone to pitting development. The mean erosion rates of the best two Ti-alloys examined here were about a factor of three higher than identically tested 316LN stainless steel following a low temperature carburizing treatment, but this difference is considered minor given that the rate for both materials is very low/manageable and represents a through-thickness property for the Ti-alloys. A nitriding surface treatment was also evaluated as a potential method to further increase the cavitation-erosion resistance of these alloys in Hg, but the selected treatment proved largely ineffective. Recommendations for further work to evaluate the efficacy of Ti-based alloys for use in high-powered targets for the Spallation Neutron Source are given.

  8. Preliminary Analysis of the Multisphere Neutron Spectrometer

    NASA Technical Reports Server (NTRS)

    Goldhagen, P.; Kniss, T.; Wilson, J. W.; Singleterry, R. C.; Jones, I. W.; VanSteveninck, W.

    2003-01-01

    Crews working on present-day jet aircraft are a large occupationally exposed group with a relatively high average effective dose from galactic cosmic radiation. Crews of future high-speed commercial aircraft flying at higher altitudes would be even more exposed. To help reduce the significant uncertainties in calculations of such exposures, the Atmospheric Ionizing Radiation (AIR) Project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on five flights of a NASA ER-2 high-altitude aircraft. The primary AIR instrument was a highly sensitive extended-energy multisphere neutron spectrometer with lead and steel shells placed within the moderators of two of its 14 detectors to enhance response at high energies. Detector responses were calculated for neutrons and charged hadrons at energies up to 100 GeV using MCNPX. Neutron spectra were unfolded from the measured count rates using the new MAXED code. We have measured the cosmic-ray neutron spectrum (thermal to greater than 10 GeV), total neutron fluence rate, and neutron effective dose and dose equivalent rates and their dependence on altitude and geomagnetic cutoff. The measured cosmic-ray neutron spectra have almost no thermal neutrons, a large "evaporation" peak near 1 MeV and a second broad peak near 100 MeV which contributes about 69% of the neutron effective dose. At high altitude, geomagnetic latitude has very little effect on the shape of the spectrum, but it is the dominant variable affecting neutron fluence rate, which was 8 times higher at the northernmost measurement location than it was at the southernmost. The shape of the spectrum varied only slightly with altitude from 21 km down to 12 km (56 - 201 grams per square centimeter atmospheric depth), but was significantly different on the ground. In all cases, ambient dose equivalent was greater than effective dose for cosmic-ray neutrons.

  9. Preliminary results of SPIRAL-2 thermo mechanical neutron converter characteristics

    NASA Astrophysics Data System (ADS)

    Udup, E.; Acosta, G.; Bermúdez, J.; Sajo-Bohus, L.; Tecchio, L.

    2012-02-01

    A preliminary design of a neutron converter module (NCM) for SPIRAL 2 Project is presented, main characteristics are given. Neutrons, produced by bombarding a carbon converter with a 40 MeV deuteron beam, 5 mA current for power up to 200 kW, induce fission reactions in target. The neutron converter, a high speed rotating wheel, operates at the temperature range between 1650-1850 °C. Vacuum restrictions and material radiation degradation, as well as a continuous three month operation were considered into structural analysis employing the ANSYS software. Preliminary tests indicate that the assembly withstands operating conditions under a vacuum up to 10-4 mbar, temperature up to 350°C, lack of lubricant and a radiation dose rate around 105 Gy/h. The results of thermomechanical simulations, considering temperature gradients, deformation and equivalent stress are presented.

  10. Geohydrologic data collected from shallow neutron-access boreholes and resultant-preliminary geohydrologic evaluations, Yucca Mountain area, Nye County, Nevada

    SciTech Connect

    Blout, D.O.; Hammermeister, D.P.; Loskot, C.L.; Chornack, M.P.

    1994-12-31

    In cooperation with the US Department of Energy, 74 neutron-access boreholes were drilled in and near the southwestern part of the Nevada Test Site, Nye County, Nevada. Drilling, coring, sample collection and handling, and lithologic and preliminary geohydrologic data are presented in this report. The boreholes were drilled in a combination of alluvium/colluvium, ash-flow tuff, ash-fall tuff, or bedded tuff to depths of 4.6 to 36.6 meters. Air was used as a drilling medium to minimize disturbance of the water content and water potential of drill cuttings, core, and formation rock. Drill cuttings were collected at approximately 0.6-meter intervals. Core was taken at selected intervals from the alluvium/colluvium using drive-coring methods and from tuff using rotary-coring methods. Nonwelded and bedded tuffs were continuously cored using rotary-coring methods. Gravimetric water-content and water-potential values of core generally were greater than those of corresponding drill cuttings. Gravimetric water-content, porosity, and water-potential values of samples generally decreased, and bulk density values increased, as the degree of welding increased. Grain-density values remained fairly constant with changes in the degree of welding. A high degree of spatial variability in water-content and water-potential profiles was noted in closely spaced boreholes that penetrate similar lithologic subunits and was also noted in adjacent boreholes located in different topographic positions. Variability within a thick lithologic unit usually was small. 18 refs., 21 figs., 17 tabs.

  11. Preliminary calibration of the ACP safeguards neutron counter

    NASA Astrophysics Data System (ADS)

    Lee, T. H.; Kim, H. D.; Yoon, J. S.; Lee, S. Y.; Swinhoe, M.; Menlove, H. O.

    2007-10-01

    The Advanced Spent Fuel Conditioning Process (ACP), a kind of pyroprocess, has been developed at the Korea Atomic Energy Research Institute (KAERI). Since there is no IAEA safeguards criteria for this process, KAERI has developed a neutron coincidence counter to make it possible to perform a material control and accounting (MC&A) for its ACP materials for the purpose of a transparency in the peaceful uses of nuclear materials at KAERI. The test results of the ACP Safeguards Neutron Counter (ASNC) show a satisfactory performance for the Doubles count measurement with a low measurement error for its cylindrical sample cavity. The neutron detection efficiency is about 21% with an error of ±1.32% along the axial direction of the cavity. Using two 252Cf neutron sources, we obtained various parameters for the Singles and Doubles rates for the ASNC. The Singles, Doubles, and Triples rates for a 252Cf point source were obtained by using the MCNPX code and the results for the ft8 cap multiplicity tally option with the values of ɛ, fd, and ft measured with a strong source most closely match the measurement results to within a 1% error. A preliminary calibration curve for the ASNC was generated by using the point model equation relationship between 244Cm and 252Cf and the calibration coefficient for the non-multiplying sample is 2.78×10 5 (Doubles counts/s/g 244Cm). The preliminary calibration curves for the ACP samples were also obtained by using an MCNPX simulation. A neutron multiplication influence on an increase of the Doubles rate for a metal ingot and UO2 powder is clearly observed. These calibration curves will be modified and complemented, when hot calibration samples become available. To verify the validity of this calibration curve, a measurement of spent fuel standards for a known 244Cm mass will be performed in the near future.

  12. Toward a New Evaluation of Neutron Standards

    NASA Astrophysics Data System (ADS)

    Carlson, A. D.; Pronyaev, V. G.; Capote, R.; Hale, G. M.; Hambsch, F.-J.; Kawano, T.; Kunieda, S.; Mannhart, W.; Nelson, R. O.; Neudecker, D.; Schillebeeckx, P.; Simakov, S.; Smith, D. L.; Talou, P.; Tao, X.; Wallner, A.; Wang, W.

    2016-02-01

    Measurements related to neutron cross section standards and certain prompt neutron fission spectra are being evaluated. In addition to the standard cross sections, investigations of reference data that are not as well known as the standards are being considered. Procedures and codes for performing this work are discussed. A number of libraries will use the results of this standards evaluation for new versions of their libraries. Most of these data have applications in neutron dosimetry.

  13. Preliminary On-Orbit Neutron Dose Equivalent and Energy Spectrum Results from the ISS-RAD Fast Neutron Detector (FND)

    NASA Technical Reports Server (NTRS)

    Semones, Edward; Leitgab, Martin

    2016-01-01

    The ISS-RAD instrument was activated on ISS on February 1st, 2016. Integrated in ISS-RAD, the Fast Neutron Detector (FND) performs, for the first time on ISS, routine and precise direct neutron measurements between 0.5 and 8 MeV. Preliminary results for neutron dose equivalent and neutron flux energy distributions from online/on-board algorithms and offline ground analyses will be shown, along with comparisons to simulated data and previously measured neutron spectral data. On-orbit data quality and pre-launch analysis validation results will be discussed as well.

  14. Evaluation of a Polyvinyl Toluene Neutron Counter Array

    SciTech Connect

    Robert Hayes

    2008-03-01

    The purpose of this article is to simulate the performance of a neutron detector array for empirical configuration optimization and preliminary algorithm evaluation. Utilizing a compact array of borated Polyvinyl Toluene light pipes and Photomultiplier Tubes, pulse shape analysis, standard spectral histogramming, and multiplicity counting can enable neutron measurements for multiple applications. Results demonstrate that analysis with Monte Carlo N-Particle (MCNP) can be used to obtain a better understanding of field measurement results and aid in algorithm development for unfolding in conjunction with detector optimization. Use of a handheld neutron spectrometer has promise of widespread applicability. By correlating MCNP results with empirical measurements, substantial confidence can be placed on predicting detector response to sufficiently similar spectral sources under alternate experimental configurations. In addition, use of the detector has substantial promise for operational health physics applications.

  15. Covariance Evaluation Methodology for Neutron Cross Sections

    SciTech Connect

    Herman,M.; Arcilla, R.; Mattoon, C.M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.; Pritychenko, b.; Songzoni, A.A.

    2008-09-01

    We present the NNDC-BNL methodology for estimating neutron cross section covariances in thermal, resolved resonance, unresolved resonance and fast neutron regions. The three key elements of the methodology are Atlas of Neutron Resonances, nuclear reaction code EMPIRE, and the Bayesian code implementing Kalman filter concept. The covariance data processing, visualization and distribution capabilities are integral components of the NNDC methodology. We illustrate its application on examples including relatively detailed evaluation of covariances for two individual nuclei and massive production of simple covariance estimates for 307 materials. Certain peculiarities regarding evaluation of covariances for resolved resonances and the consistency between resonance parameter uncertainties and thermal cross section uncertainties are also discussed.

  16. Preliminary investigations of Monte Carlo Simulations of neutron energy and LET spectra for fast neutron therapy facilities

    SciTech Connect

    Kroc, T.K.; /Fermilab

    2009-10-01

    No fast neutron therapy facility has been built with optimized beam quality based on a thorough understanding of the neutron spectrum and its resulting biological effectiveness. A study has been initiated to provide the information necessary for such an optimization. Monte Carlo studies will be used to simulate neutron energy spectra and LET spectra. These studies will be bench-marked with data taken at existing fast neutron therapy facilities. Results will also be compared with radiobiological studies to further support beam quality ptimization. These simulations, anchored by this data, will then be used to determine what parameters might be optimized to take full advantage of the unique LET properties of fast neutron beams. This paper will present preliminary work in generating energy and LET spectra for the Fermilab fast neutron therapy facility.

  17. An evaluated neutronic data file for bismuth

    SciTech Connect

    Guenther, P.T.; Lawson, R.D.; Meadows, J.W.; Smith, A.B.; Smith, D.L.; Sugimoto, M. ); Howerton, R.J. )

    1989-11-01

    A comprehensive evaluated neutronic data file for bismuth, extending from 10{sup {minus}5} eV to 20.0 MeV, is described. The experimental database, the application of the theoretical models, and the evaluation rationale are outlined. Attention is given to uncertainty specification, and comparisons are made with the prior ENDF/B-V evaluation. The corresponding numerical file, in ENDF/B-VI format, has been transmitted to the National Nuclear Data Center, Brookhaven National Laboratory. 106 refs., 10 figs., 6 tabs.

  18. Preliminary Criticality Safety Evaluation for In Situ Grouting in the Subsurface Disposal Area

    SciTech Connect

    Slate, Lawrence J; Taylor, Joseph Todd

    2000-08-01

    A preliminary criticality safety evaluation is presented for in situ grouting in the Subsurface Disposal Area (SDA) at the Idaho National Engineering Laboratory. The grouting materials evaluated are cement and paraffin. The evaluation determines physical and administrative controls necessary to preclude criticality and identifies additional information required for a final criticality safety evaluation. The evaluation shows that there are no criticality concerns with cementitious grout but a neutron poison such as boron would be required for the use of the paraffin matrix.

  19. Preliminary Criticality Safety Evaluation for In Situ Grouting in the Subsurface Disposal Area

    SciTech Connect

    Slate, L.J.; Taylor, J.T.

    2000-08-31

    A preliminary criticality safety evaluation is presented for in situ grouting in the Subsurface Disposal Area (SDA) at the Idaho National Engineering Laboratory. The grouting materials evaluated are cement and paraffin. The evaluation determines physical and administrative controls necessary to preclude criticality and identifies additional information required for a final criticality safety evaluation. The evaluation shows that there are no criticality concerns with cementitious grout but a neutron poison such as boron would be required for the use of the paraffin matrix.

  20. Radioactive waste shredding: Preliminary evaluation

    SciTech Connect

    Soelberg, N.R.; Reimann, G.A.

    1994-07-01

    The critical constraints for sizing solid radioactive and mixed wastes for subsequent thermal treatment were identified via a literature review and a survey of shredding equipment vendors. The types and amounts of DOE radioactive wastes that will require treatment to reduce the waste volume, destroy hazardous organics, or immobilize radionuclides and/or hazardous metals were considered. The preliminary steps of waste receipt, inspection, and separation were included because many potential waste treatment technologies have limits on feedstream chemical content, physical composition, and particle size. Most treatment processes and shredding operations require at least some degree of feed material characterization. Preliminary cost estimates show that pretreatment costs per unit of waste can be high and can vary significantly, depending on the processing rate and desired output particle size.

  1. Preliminary neutron crystallographic analysis of selectively CH3-protonated, deuterated rubredoxin from Pyrococcus furiosus

    SciTech Connect

    Weiss, Kevin L; Meilleur, Flora; Blakeley, Matthew; Myles, Dean A A

    2008-01-01

    Neutron crystallography is used to locate hydrogen atoms in biological materials and can distinguish between negatively scattering hydrogen and positively scattering deuterium substituted positions in isomorphous neutron structures. Recently, Hauptman and Langs (2003) have shown that neutron diffraction data can be used to solve macromolecular structures by direct methods and that solution is aided by the presence of negatively scattering hydrogen atoms in the structure. Selective labeling protocols allow the design and production of H/D-labeled macromolecular structures in which the ratio of hydrogen to deuterium atoms can be precisely controlled. We have applied methyl-selective labeling protocols to introduce (1H-delta methyl)-leucine and (1H-gamma methyl)-valine into deuterated rubredoxin from Pyrococcus furiosus (PfRd). Here we report on the production, crystallization, and preliminary neutron analysis of the selectively CH3-protonated, deuterated PfRd sample, which provided a high quality neutron data set extending to 1.75 resolution at the new LADI-III instrument at the Insititut Laue-Langevin. Preliminary analysis of neutron density maps allows unambiguous assignment of the positions of hydrogen atoms at the methyl groups of the valine and leucine residues in the otherwise deuterated rubredoxin structure.

  2. Preliminary study of nuclear fuel element testing based on coded source neutron imaging

    SciTech Connect

    Sheng Wang; Hang Li; Chao Cao; Yang Wu; Heyong Huo; Bin Tang

    2015-07-01

    Neutron radiography (NR) is one of the most important nondestructive testing methods, which is sensitive to low density materials. Especially, Neutron transfer imaging method could be used to test radioactivity materials refraining from γ effect, but it is difficult to realize tomography. Coded source neutron imaging (CSNI) is a newly NR method developed fast in the last several years. The distance between object and detector is much longer than traditional NR, which could be used to test radioactivity materials. With pre-reconstruction process from fold-cover projections, CSNI could easily realize tomography. This thesis carries out preliminary study on the nuclear fuel element testing by coded source neutron imaging. We calculate different enrichment, flaws and activity in nuclear fuel elements tested by CSNI with Monte-Carlo simulation. The results show that CSNI could be a useful testing method for nuclear fuel element testing. (authors)

  3. Preliminary engineering assessment of the HCLL and HCPB Neutron Activation System

    SciTech Connect

    Calderoni, Pattrick; Leichtle, Dieter; Angelone, Maurizio; Klix, Axel

    2015-07-01

    The Neutron Activation System (NAS) is one of the four types of neutronics sensors considered for the testing of the HCLL and HCPB Test Blanket Module (TBM) in ITER. It measures the absolute neutron flux intensity with information on the neutron spectrum in selected positions of the TBM. The working principle of the NAS is as follows: the system moves small activation probes (capsules) into selected positions in the TBM (irradiation ends) by means of pneumatic transport with pressurized helium gas; the capsules are irradiated for a selected period, depending on their materials composition (several tens of seconds up to the full plasma pulse length); immediately after the irradiation they are extracted and transported to a gamma spectrometer by means of the same pneumatic transport system; the gamma spectrometer determines the induced gamma activity; the neutron flux and neutron fluence is calculated from the measured gamma activity and the known activation cross section of the materials in the activation probe; after the measurement the capsule is sent either to a disposal or storage (for later measurement). This paper summarizes the results of the feasibility assessment of the TBM NAS in the conceptual design phase, including design justification, identification of requirements based on the expected operating conditions in ITER and preliminary engineering assessment of the activation materials, irradiation ends integration in the modules design and the counting station. (authors)

  4. Preliminary neutronic analysis of a cavity test reactor

    NASA Technical Reports Server (NTRS)

    Whitmarsh, C. L., Jr.

    1973-01-01

    A reference configuration was calculated for a cavity test reactor to be used for testing the gascore nuclear rocket concept. A thermal flux of 4.1 x 10 to the 14th power neutrons per square centimeter per second in the cavity was provided by a driver fuel loading of 6.4 kg of enriched uranium in MTR fuel elements. The reactor was moderated and cooled by heavy water and reflected with 25.4 cm of beryllium. Power generation of 41.3 MW in the driver fuel is rejected to a heat sink. Design effort was directed toward minimization of driver power while maintaining 2.7 MW in the cavity during a test run. Ancillary data on material reactivity worths, reactivity coefficients, flux spectra, and power distributions are reported.

  5. Preliminary neutron and X-ray crystallographic studies of equine cyanomethemoglobin

    SciTech Connect

    Kovalevsky, A.Y.; Fisher, S.Z.; Seaver, S.; Mustyakimov, M.; Sukumar, N.; Langan, P.; Mueser, T.C.; Hanson, B.L.

    2010-08-18

    Room-temperature and 100 K X-ray and room-temperature neutron diffraction data have been measured from equine cyanomethemoglobin to 1.7 {angstrom} resolution using a home source, to 1.6 {angstrom} resolution on NE-CAT at the Advanced Photon Source and to 2.0 {angstrom} resolution on the PCS at Los Alamos Neutron Science Center, respectively. The cyanomethemoglobin is in the R state and preliminary room-temperature electron and neutron scattering density maps clearly show the protonation states of potential Bohr groups. Interestingly, a water molecule that is in the vicinity of the heme group and coordinated to the distal histidine appears to be expelled from this site in the low-temperature structure.

  6. A preliminary neutron diffraction study of rasburicase, a recombinant urate oxidase enzyme, complexed with 8-azaxanthin

    SciTech Connect

    Budayova-Spano, Monika; Bonneté, Françoise; Ferté, Natalie; El Hajji, Mohamed; Meilleur, Flora; Blakeley, Matthew Paul; Castro, Bertrand

    2006-03-01

    Neutron diffraction data of hydrogenated recombinant urate oxidase enzyme (Rasburicase), complexed with a purine-type inhibitor 8-azaxanthin, was collected to 2.1 Å resolution from a crystal grown in D{sub 2}O by careful control and optimization of crystallization conditions via knowledge of the phase diagram. Deuterium atoms were clearly seen in the neutron-scattering density map. Crystallization and preliminary neutron diffraction measurements of rasburicase, a recombinant urate oxidase enzyme expressed by a genetically modified Saccharomyces cerevisiae strain, complexed with a purine-type inhibitor (8-azaxanthin) are reported. Neutron Laue diffraction data were collected to 2.1 Å resolution using the LADI instrument from a crystal (grown in D{sub 2}O) with volume 1.8 mm{sup 3}. The aim of this neutron diffraction study is to determine the protonation states of the inhibitor and residues within the active site. This will lead to improved comprehension of the enzymatic mechanism of this important enzyme, which is used as a protein drug to reduce toxic uric acid accumulation during chemotherapy. This paper illustrates the high quality of the neutron diffraction data collected, which are suitable for high-resolution structural analysis. In comparison with other neutron protein crystallography studies to date in which a hydrogenated protein has been used, the volume of the crystal was relatively small and yet the data still extend to high resolution. Furthermore, urate oxidase has one of the largest primitive unit-cell volumes (space group I222, unit-cell parameters a = 80, b = 96, c = 106 Å) and molecular weights (135 kDa for the homotetramer) so far successfully studied with neutrons.

  7. Evaluation of an iron-filtered epithermal neutron beam for neutron-capture therapy.

    PubMed

    Musolino, S V; McGinley, P H; Greenwood, R C; Kliauga, P; Fairchild, R G

    1991-01-01

    An epithermal neutron filter using iron, aluminum, and sulfur was evaluated to determine if the therapeutic performance could be improved with respect to aluminum-sulfur-based filters. An empirically optimized filter was developed that delivered a 93% pure beam of 24-keV epithermal neutrons. It was expected that a thick filter using iron with a density thickness greater than 200 g/cm2 would eliminate the excess gamma contamination found in Al-S filters. This research showed that prompt gamma production from neutron interactions in iron was the dominant dose component. Dosimetric parameters of the beam were determined from the measurement of absorbed dose in air, thermal neutron flux in a head phantom, neutron and gamma spectroscopy, and microdosimetry.

  8. Introducing Nuclear Data Evaluations of Prompt Fission Neutron Spectra

    SciTech Connect

    Neudecker, Denise

    2015-06-17

    Nuclear data evaluations provide recommended data sets for nuclear data applications such as reactor physics, stockpile stewardship or nuclear medicine. The evaluated data are often based on information from multiple experimental data sets and nuclear theory using statistical methods. Therefore, they are collaborative efforts of evaluators, theoreticians, experimentalists, benchmark experts, statisticians and application area scientists. In this talk, an introductions is given to the field of nuclear data evaluation at the specific example of a recent evaluation of the outgoing neutron energy spectrum emitted promptly after fission from 239Pu and induced by neutrons from thermal to 30 MeV.

  9. Neutron based evaluation in support of NEAMS

    SciTech Connect

    Vogel, Sven C.; Bourke, Mark Andrew; Losko, Adrian Simon

    2016-06-07

    The primary objective of the Advanced Non-Destructive fuel Examination (ANDE) work package is to develop capability that has the potential to accelerate insight and development of ceramic and metallic fuels. Establishing unique validation opportunities for new models is a key component of this effort. To explore opportunities a series of interactions were held with NEAMS modelers at LANL. The focus was to identify experiments that draw on the unique capabilities of neutron scattering and imaging for studies of nuclear fuel particularly in areas where experimental data can be valuable for of models validation. The neutron characterization techniques applied in the ANDE program span length scales from millimeter to micrometer to angstroms. Spatial heterogeneities of interest include cracks, pores and inclusions, crystal structure, phase composition, stoichiometry texture, chemistry and atomic thermal motion. Neutrons offer characterization opportunities that are distinct from other probes such as X-rays, electrons or protons. This report describes a variety of opportunities whereby neutron data can be related to models and lists some opportunities.

  10. EPICS V4 Evaluation for SNS Neutron Data

    SciTech Connect

    Kasemir, Kay; Pearson, Matthew R; Guyotte, Greg S

    2015-01-01

    Version 4 of the Experimental Physics and Industrial Control System (EPICS) toolkit allows defining application-specific structured data types (pvData) and offers a network protocol for their efficient exchange (pvAccess). We evaluated V4 for the transport of neutron events from the detectors of the Spallation Neutron Source (SNS) to data acquisition and experiment monitoring systems. This includes the comparison of possible data structures, performance tests, and experience using V4 in production on a beam line.

  11. Preliminary neutronic studies for the liquid-salt-cooled very hightemperature reactor (LS-VHTR).

    SciTech Connect

    Kim, T. K.; Taiwo, T. A.; Yang, W. S.

    2005-10-05

    Preliminary neutronic studies have been performed in order to provide guidelines to the design of a liquid-salt cooled Very High Temperature Reactor (LS-VHTR) using Li{sub 2}BeF{sub 4} (FLiBe) as coolant and a solid cylindrical core. The studies were done using the lattice codes (WIMS8 and DRAGON) and the linear reactivity model to estimate the core reactivity balance, fuel composition, discharge burnup, and reactivity coefficients. An evaluation of the lattice codes revealed that they give very similar accuracy as the Monte Carlo MCNP4C code for the prediction of the fuel element multiplication factor (kinf) and the double heterogeneity effect of the coated fuel particles in the graphite matrix. The loss of coolant from the LS-VHTR core following coolant voiding was found to result in a positive reactivity addition, due primarily to the removal of the strong neutron absorber Li-6. To mitigate this positive reactivity addition and its impact on reactor design (positive void reactivity coefficient), the lithium in the coolant must be enriched to greater than 99.995% in its Li-7 content. For the reference LS-VHTR considered in this work, it was found that the magnitude of the coolant void reactivity coefficient (CVRC) is quite small (less than $1 for 100% voiding). The coefficient was found to become more negative or less positive with increase in the lithium enrichment (Li-7 content). It was also observed that the coefficient is positive at the beginning of cycle and becomes more negative with increasing burnup, indicating that by using more than one fuel batch, the coefficient could be made negative at the beginning of cycle. It might, however, still be necessary at the beginning of life to design for a negative CVRC value. The study shows that this can be done by using burnable poisons (erbium is a leading candidate) or by changing the reference assembly design (channel dimensions) in order to modify the neutron spectrum. Parametric studies have been performed to

  12. Development and preliminary verification of the 3D core neutronic code: COCO

    SciTech Connect

    Lu, H.; Mo, K.; Li, W.; Bai, N.; Li, J.

    2012-07-01

    As the recent blooming economic growth and following environmental concerns (China)) is proactively pushing forward nuclear power development and encouraging the tapping of clean energy. Under this situation, CGNPC, as one of the largest energy enterprises in China, is planning to develop its own nuclear related technology in order to support more and more nuclear plants either under construction or being operation. This paper introduces the recent progress in software development for CGNPC. The focus is placed on the physical models and preliminary verification results during the recent development of the 3D Core Neutronic Code: COCO. In the COCO code, the non-linear Green's function method is employed to calculate the neutron flux. In order to use the discontinuity factor, the Neumann (second kind) boundary condition is utilized in the Green's function nodal method. Additionally, the COCO code also includes the necessary physical models, e.g. single-channel thermal-hydraulic module, burnup module, pin power reconstruction module and cross-section interpolation module. The preliminary verification result shows that the COCO code is sufficient for reactor core design and analysis for pressurized water reactor (PWR). (authors)

  13. Evaluation of the Prompt Fission Neutron Spectrum of Thermal-neutron Induced Fission in U-235

    NASA Astrophysics Data System (ADS)

    Trkov, A.; Capote, R.

    A new evaluation of the prompt fission neutron spectra (PFNS) for the neutron-induced fission of the U-235 nucleus is presented. By using differential data as "shape data" good consistency was achieved between selected sets of differential data. A fit of differential PFNS data with the generalised least-squares method using the GANDR code allowed the estimation of the uncertainties and correlations. All experimental data were consistently fitted in a model independent way giving a PFNS average energy of2.000 MeV with an estimated 9 keV uncertainty.

  14. Neutron-emission measurements at a white neutron source

    SciTech Connect

    Haight, Robert C

    2010-01-01

    Data on the spectrum of neutrons emittcd from neutron-induced reactions are important in basic nuclear physics and in applications. Our program studies neutron emission from inelastic scattering as well as fission neutron spectra. A ''white'' neutron source (continuous in energy) allows measurements over a wide range of neutron energies all in one experiment. We use the tast neutron source at the Los Alamos Neutron Science Center for incident neutron energies from 0.5 MeV to 200 MeV These experiments are based on double time-of-flight techniques to determine the energies of the incident and emitted neutrons. For the fission neutron measurements, parallel-plate ionization or avalanche detectors identify fission in actinide samples and give the required fast timing pulse. For inelastic scattering, gamma-ray detectors provide the timing and energy spectroscopy. A large neutron-detector array detects the emitted neutrons. Time-of-flight techniques are used to measure the energies of both the incident and emitted neutrons. Design considerations for the array include neutron-gamma discrimination, neutron energy resolution, angular coverage, segmentation, detector efficiency calibration and data acquisition. We have made preliminary measurements of the fission neutron spectra from {sup 235}U, {sup 238}U, {sup 237}Np and {sup 239}Pu. Neutron emission spectra from inelastic scattering on iron and nickel have also been investigated. The results obtained will be compared with evaluated data.

  15. A preliminary area survey of neutron radiation levels associated with the NASA variable energy cyclotron horizontal neutron delivery system

    NASA Technical Reports Server (NTRS)

    Roberts, W. K.; Leonard, R. F.

    1976-01-01

    The 25 MeV deuteron beam from the NASA variable energy cyclotron incident on a thick beryllium target will deliver a tissue neutron dose rate of 2.14 rad micron A-min at a source to skin distance of 125 cm. A neutron survey of the existing hallways with various shielding configurations made during operating of the horizontal neutron delivery system indicates that minimal amounts of additional neutron shielding material are required to provide a low level radiation environment within a self-contained neutron therapy control station. Measurements also indicate that the primary neutron distribution delivered by a planned vertical delivery system will be minimally perturbed by neutrons backscattered from the floor.

  16. A Computerized Library and Evaluation System for Integral Neutron Experiments.

    ERIC Educational Resources Information Center

    Hampel, Viktor E.; And Others

    A computerized library of references to integral neutron experiments has been developed at the Lawrence Radiation Laboratory at Livermore. This library serves as a data base for the systematic retrieval of documents describing diverse critical and bulk nuclear experiments. The evaluation and reduction of the physical parameters of the experiments…

  17. Preliminary Neutronics Design Studies for a Molten Salt Blanket LIFE Engine

    SciTech Connect

    Powers, J

    2008-10-23

    The Laser Inertial Confinement Fusion Fission Energy (LIFE) Program being developed at Lawrence Livermore National Laboratory (LLNL) aims to design a hybrid fission-fusion subcritical nuclear engine that uses a laser-driven Inertial Confinement Fusion (ICF) system to drive a subcritical fission blanket. This combined fusion-fission hybrid system could be used for generating electricity, material transmutation or incineration, or other applications. LIFE does not require enriched fuel since it is a sub-critical system and LIFE can sustain power operation beyond the burnup levels at which typical fission reactors need to be refueled. In light of these factors, numerous options have been suggested and are being investigated. Options being investigated include fueling LIFE engines with spent nuclear fuel to aid in disposal/incineration of commercial spent nuclear fuel or using depleted uranium or thorium fueled options to enhance proliferation resistance and utilize non-fissile materials [1]. LIFE engine blanket designs using a molten salt fuel system represent one area of investigation. Possible applications of a LIFE engine with a molten salt blanket include uses as a spent nuclear fuel burner, fissile fuel breeding platform, and providing a backup alternative to other LIFE engine blanket designs using TRISO fuel particles in case the TRISO particles are found to be unable to withstand the irradiation they will be subjected to. These molten salts consist of a mixture of LiF with UF{sub 4} or ThF{sub 4} or some combination thereof. Future systems could look at using PuF{sub 3} or PuF{sub 4} as well, though no work on such system with initial plutonium loadings has been performed for studies documented in this report. The purpose of this report is to document preliminary neutronics design studies performed to support the development of a molten salt blanket LIFE engine option, as part of the LIFE Program being performed at Lawrence Livermore National laboratory

  18. Preliminary Neutronic Study of D2O-cooled High Conversion PWRs

    SciTech Connect

    Hikaru Hiruta; Gilles Youinou

    2013-10-01

    This paper presents a preliminary neutronics analysis of tight-pitch D2O-cooled high-conversion PWRs loaded with MOX fuel aiming at high Pu conversion and negative void coefficient. SCALE6.1 has been exclusively utilized for this study. The analyses are performed in two separate parts. The first part of this paper investigates the performance of axial and internal blankets and seeks break-even or near-breeder core even without the presence of radial blankets. The second part of this paper performs sensitivity and uncertainty analyses of integral parameters (keff and void coefficient) for selected systems in order to analyze the characters of this high-conversion PWR from different aspects.

  19. Evaluation of spectral unfolding techniques for neutron spectroscopy

    SciTech Connect

    Sunden, Erik Andersson; Conroy, S.; Ericsson, G.; Johnson, M. Gatu; Giacomelli, L.; Hellesen, C.; Hjalmarsson, A.; Ronchi, E.; Sjoestrand, H.; Weiszflog, M.; Kaellne, J.; Gorini, G.; Tardocchi, M.

    2008-03-12

    The precision of the JET installations of MAXED, GRAVEL and the L-curve version of MAXED has been evaluated by using synthetic neutron spectra. We have determined the number of counts needed for the detector systems NE213 and MPR to get an error below 10% of the MAXED unfolded neutron spectra is determined to be {approx}10{sup 6} and {approx}10{sup 4}, respectively. For GRAVEL the same number is {approx}10{sup 7} and {approx}3{center_dot}10{sup 4} for NE213 and MPR, respectively.

  20. Evaluation of Neutron Response of Criticality Accident Alarm System Detector to Quasi-Monoenergetic 24 keV Neutrons

    NASA Astrophysics Data System (ADS)

    Tsujimura, Norio; Yoshida, Tadayoshi; Yashima, Hiroshi

    The criticality accident alarm system (CAAS), which was recently developed and installed at the Japan Atomic Energy Agency's Tokai Reprocessing Plant, consists of a plastic scintillator combined with a cadmium-lined polyethylene moderator and thereby responds to both neutrons and gamma rays. To evaluate the neutron absorbed dose rate response of the CAAS detector, a 24 keV quasi-monoenergetic neutron irradiation experiment was performed at the B-1 facility of the Kyoto University Research Reactor. The detector's evaluated neutron response was confirmed to agree reasonably well with prior computer-predicted responses.

  1. Preliminary energy-filtering neutron imaging with time-of-flight method on PKUNIFTY: A compact accelerator based neutron imaging facility at Peking University

    NASA Astrophysics Data System (ADS)

    Wang, Hu; Zou, Yubin; Wen, Weiwei; Lu, Yuanrong; Guo, Zhiyu

    2016-07-01

    Peking University Neutron Imaging Facility (PKUNIFTY) works on an accelerator-based neutron source with a repetition period of 10 ms and pulse duration of 0.4 ms, which has a rather low Cd ratio. To improve the effective Cd ratio and thus improve the detection capability of the facility, energy-filtering neutron imaging was realized with the intensified CCD camera and time-of-flight (TOF) method. Time structure of the pulsed neutron source was firstly simulated with Geant4, and the simulation result was evaluated with experiment. Both simulation and experiment results indicated that fast neutrons and epithermal neutrons were concentrated in the first 0.8 ms of each pulse period; meanwhile in the period of 0.8-2.0 ms only thermal neutrons existed. Based on this result, neutron images with and without energy filtering were acquired respectively, and it showed that detection capability of PKUNIFTY was improved with setting the exposure interval as 0.8-2.0 ms, especially for materials with strong moderating capability.

  2. Preliminary Evaluation of a New Cosmology Curriculum

    NASA Astrophysics Data System (ADS)

    Coble, Kimberly A.; Martin, Dominique; Hayes, Patrycia; Targett, Tom; Bailey, Janelle M.; Cominsky, Lynn R.

    2015-01-01

    Informed by our research on student understanding of cosmology, The Big Ideas in Cosmology is an immersive set of web-based learning modules that integrates text, figures, and visualizations with short and long interactive tasks and real cosmological data. This enables the transformation of general education astronomy and cosmology classes from primarily lecture and book-based courses to a more engaging format that builds important STEM skills.During the spring 2014 semester, we field-tested a subset of chapters with the general education astronomy and cosmology classes at Sonoma State University in a flipped-classroom format. We administered pre and post content and attitude assessments in the two flipped classes as well as two lecture classes. The majority of cosmology students had taken astronomy before whereas the astronomy students had not.When switching to an active mode of learning (e.g., flipped classroom instead of lecture), many instructors report pushback from students. We saw this effect from students in course evaluations, who reported dissatisfaction with "having to do more work." However, the students in the flipped section in astronomy made greater gains on the multiple choice content assessment than the students in either of the two lecture sections. On the attitude assessment (the CLASS), the cosmology students made a small shift toward more expert-like opinions. Preliminary results from open-ended content surveys indicate that, prior to instruction, students had difficulty answering 'why' or 'how do we know' questions; that post-instruction, students are less likely to respond "I don't know" or to leave an answer blank; and that students using the modules made gains in their content knowledge.Module development was supported by NASA ROSES E/PO Grant #NNXl0AC89G, the Illinois Space Grant Consortium, the Fermi E/PO program, Sonoma State University's Space Science Education and Public Outreach Group, and Great River Technology

  3. Superconducting Gamma/Neutron Spectrometer Task 1 Completion Report Evaluation of Candidate Neutron-Sensitive Materials

    SciTech Connect

    Bell, Z.W.; Lamberti, V.E.

    2002-06-20

    A review of the scientific literature regarding boron- and lithium-containing compounds was completed. Information such as Debye temperature, heat capacity, superconductivity properties, physical and chemical characteristics, commercial availability, and recipes for synthesis was accumulated and evaluated to develop a list of neutron-sensitive materials likely to perform properly in the spectrometer. The best candidate borides appear to be MgB{sub 2} (a superconductor with T{sub c} = 39 K), B{sub 6}Si, B{sub 4}C, and elemental boron; all are commercially available. Among the lithium compounds are LiH, LiAl, Li{sub 12}Si{sub 7}, and Li{sub 7}Sn{sub 2}. These materials have or are expected to have high Debye temperatures and sufficiently low heat capacities at 100 mK to produce a useful signal. The responses of {sup 10}B and {sup 6}Li to a fission neutron spectrum were also estimated. These demonstrated that the contribution of scattering events is no more than 3% in a boron-based system and 1.5% in a lithium-based system. This project is concerned with the development of materials for use in a cryogenic neutron spectrometer and is complementary to work in progress by Labov at LLNL to develop a cryogenic gamma ray spectrometer. Refrigeration to 100 mK lowers the heat capacity of these materials to the point that the energy of absorbed gamma and x rays, nuclei scattered by fast neutrons, and ions from (n, {alpha}) reactions produce a measurable heat pulse, from which the energy of the incident radiation may be deduced. The objective of this project is the discovery, fabrication, and testing of candidate materials with which a cryogenic neutron spectrometer may be realized.

  4. Evaluating the 239Pu prompt fission neutron spectrum induced by thermal to 30 MeV neutrons

    DOE PAGES

    Neudecker, Denise; Talou, Patrick; Kawano, Toshihiko; ...

    2016-03-15

    We present a new evaluation of the 239Pu prompt fission neutron spectrum (PFNS) induced by thermal to 30 MeV neutrons. Compared to the ENDF/B-VII.1 evaluation, this one includes recently published experimental data as well as an improved and extended model description to predict PFNS. For instance, the pre-equilibrium neutron emission component to the PFNS is considered and the incident energy dependence of model parameters is parametrized more realistically. Experimental and model parameter uncertainties and covariances are estimated in detail. Also, evaluated covariances are provided between all PFNS at different incident neutron energies. In conclusion, selected evaluation results and first benchmarkmore » calculations using this evaluation are briefly discussed.« less

  5. Evaluating the 239Pu prompt fission neutron spectrum induced by thermal to 30 MeV neutrons

    SciTech Connect

    Neudecker, Denise; Talou, Patrick; Kawano, Toshihiko; Kahler, Albert Comstock; Rising, Michael Evan; White, Morgan Curtis

    2016-03-15

    We present a new evaluation of the 239Pu prompt fission neutron spectrum (PFNS) induced by thermal to 30 MeV neutrons. Compared to the ENDF/B-VII.1 evaluation, this one includes recently published experimental data as well as an improved and extended model description to predict PFNS. For instance, the pre-equilibrium neutron emission component to the PFNS is considered and the incident energy dependence of model parameters is parametrized more realistically. Experimental and model parameter uncertainties and covariances are estimated in detail. Also, evaluated covariances are provided between all PFNS at different incident neutron energies. In conclusion, selected evaluation results and first benchmark calculations using this evaluation are briefly discussed.

  6. Evaluation of Tungsten Neutron Cross Sections in the Resolved Resonance Regions

    SciTech Connect

    Pigni, Marco T; Leal, Luiz C; Dunn, Michael E; Guber, Klaus H; Emiliani, F.; Kopecky, S.; Lampoudis, C.; Schillebeeckx, P.; Siegler, P.

    2014-01-01

    We generated a preliminary set of resonance parameters for 182-184,186W in the neutron energy range of thermal up to several keV. The evaluation methodology uses the Reich-Moore approximation to t, with the R-matrix code SAMMY, the high-resolution measurements performed in 2010 and 2012 at the GEel LINear Accelerator (GELINA) facility. Particularly for 183W, the transmission data and the capture cross sections calculated with the set of resonance parameters are compared with the experimental values, and some of the average properties of the resonance parameters are discussed. In the analyzed energy range, this work almost doubles the existing resolved resonance evaluations in the ENDF/B-VII.1 library. The analysis of the performance of the calculated cross sections based on criticality benchmarks is still in progress and it is only briefly discussed.

  7. New Resonance Parameter Evaluation of Cl Neutron Cross Sections

    SciTech Connect

    Sayer, R.O.; Guber, K.H.; Leal, L.C.; Larson, N.M.

    2005-05-24

    Better measurements and evaluations are needed for many elements where the existing evaluations or the underlying nuclear cross-section data are not sufficiently accurate for reliable calculation of criticality safety margins. Deficiencies in the existing ENDF/B-VI data evaluation for Cl led to our resonance parameter evaluation of Cl neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Our evaluation takes advantage of recent high-resolution capture and transmission measurements at the Oak Ridge Electron Linear Accelerator (ORELA) as well as older total cross-section measurements at Karlsruhe (KFK) to extend the resolved resonance energy range to 1.2 MeV with much more accurate representation of the data than previous evaluations.

  8. Non destructive examination of UN / U-Si fuel pellets using neutrons (preliminary assessment)

    SciTech Connect

    Bourke, Mark Andrew; Vogel, Sven C.; Voit, Stewart Lancaster; Mcclellan, Kenneth James; Losko, Adrian S.; Tremsin, Anton

    2016-03-31

    Tomographic imaging and diffraction measurements were performed on nine pellets; four UN/ U Si composite formulations (two enrichment levels), three pure U3Si5 reference formulations (two enrichment levels) and two reject pellets with visible flaws (to qualify the technique). The U-235 enrichments ranged from 0.2 to 8.8 wt.%. The nitride/silicide composites are candidate compositions for use as Accident Tolerant Fuel (ATF). The monophase U3Si5 material was included as a reference. Pellets from the same fabrication batches will be inserted in the Advanced Test Reactor at Idaho during 2016. The goal of the Advanced Non-destructive Fuel Examination work package is the development and application of non-destructive neutron imaging and scattering techniques to ceramic and metallic nuclear fuels. Data reported in this report were collected in the LANSCE run cycle that started in September 2015 and ended in March 2016. Data analysis is ongoing; thus, this report provides a preliminary review of the measurements and provides an overview of the characterized samples.

  9. Non destructive multi elemental analysis using prompt gamma neutron activation analysis techniques: Preliminary results for concrete sample

    SciTech Connect

    Dahing, Lahasen Normanshah; Yahya, Redzuan; Yahya, Roslan; Hassan, Hearie

    2014-09-03

    In this study, principle of prompt gamma neutron activation analysis has been used as a technique to determine the elements in the sample. The system consists of collimated isotopic neutron source, Cf-252 with HPGe detector and Multichannel Analysis (MCA). Concrete with size of 10×10×10 cm{sup 3} and 15×15×15 cm{sup 3} were analysed as sample. When neutrons enter and interact with elements in the concrete, the neutron capture reaction will occur and produce characteristic prompt gamma ray of the elements. The preliminary result of this study demonstrate the major element in the concrete was determined such as Si, Mg, Ca, Al, Fe and H as well as others element, such as Cl by analysis the gamma ray lines respectively. The results obtained were compared with NAA and XRF techniques as a part of reference and validation. The potential and the capability of neutron induced prompt gamma as tool for multi elemental analysis qualitatively to identify the elements present in the concrete sample discussed.

  10. Recent Work Leading Towards a New Evaluation of the Neutron Standards

    SciTech Connect

    Carlson, A. D.; Pronyaev, V. G.; Capote, R.; Hale, G. M.; Hambsch, F. -J.; Kawano, T.; Kunieda, S.; Mannhart, W.; Nelson, R. O.; Neudecker, D.; Schillebeeckx, P.; Simakov, S.; Smith, D. L.; Talou, P.; Tao, X.; Wallner, A.; Wang, W.

    2015-01-01

    A new version of the ENDF/B library has been planned. The first step in producing this new library is evaluating the neutron standards. An evaluation is now underway with support from a Data Development Project of the IAEA. In addition to the neutron cross section standards, new evaluations are being done for prompt fission neutron spectra and a number of reference data. Efforts have been made to handle uncertainties in a proper way in these evaluations.

  11. Recent Work Leading Towards a New Evaluation of the Neutron Standards

    SciTech Connect

    Carlson, A.D.; Pronyaev, V.G.; Capote, R.; Hale, G.M.; Hambsch, F.-J.; Kawano, T.; Kunieda, S.; Mannhart, W.; Nelson, R.O.; Neudecker, D.; Schillebeeckx, P.; Simakov, S.; Smith, D.L.; Talou, P.; Tao, X.; Wallner, A.; Wang, W.

    2015-01-15

    A new version of the ENDF/B library has been planned. The first step in producing this new library is evaluating the neutron standards. An evaluation is now underway with support from a Data Development Project of the IAEA. In addition to the neutron cross section standards, new evaluations are being done for prompt fission neutron spectra and a number of reference data. Efforts have been made to handle uncertainties in a proper way in these evaluations.

  12. Evaluation of Neutron Irradiated Silicon Carbide and Silicon Carbide Composites

    SciTech Connect

    Newsome G, Snead L, Hinoki T, Katoh Y, Peters D

    2007-03-26

    The effects of fast neutron irradiation on SiC and SiC composites have been studied. The materials used were chemical vapor deposition (CVD) SiC and SiC/SiC composites reinforced with either Hi-Nicalon{trademark} Type-S, Hi-Nicalon{trademark} or Sylramic{trademark} fibers fabricated by chemical vapor infiltration. Statistically significant numbers of flexural samples were irradiated up to 4.6 x 10{sup 25} n/m{sup 2} (E>0.1 MeV) at 300, 500 and 800 C in the High Flux Isotope Reactor at Oak Ridge National Laboratory. Dimensions and weights of the flexural bars were measured before and after the neutron irradiation. Mechanical properties were evaluated by four point flexural testing. Volume increase was seen for all bend bars following neutron irradiation. Magnitude of swelling depended on irradiation temperature and material, while it was nearly independent of irradiation fluence over the fluence range studied. Flexural strength of CVD SiC increased following irradiation depending on irradiation temperature. Over the temperature range studied, no significant degradation in mechanical properties was seen for composites fabricated with Hi-Nicalon{trademark} Type-S, while composites reinforced with Hi-Nicalon{trademark} or Sylramic fibers showed significant degradation. The effects of irradiation on the Weibull failure statistics are also presented suggesting a reduction in the Weibull modulus upon irradiation. The cause of this potential reduction is not known.

  13. Preliminary treatment planning and dosimetry for a clinical trial of neutron capture therapy using a fission converter epithermal neutron beam.

    PubMed

    Kiger, W S; Lu, X Q; Harling, O K; Riley, K J; Binns, P J; Kaplan, J; Patel, H; Zamenhof, R G; Shibata, Y; Kaplan, I D; Busse, P M; Palmer, M R

    2004-11-01

    A Phase I/II clinical trial of neutron capture therapy (NCT) was conducted at Harvard-MIT using a fission converter epithermal neutron beam. This epithermal neutron beam has nearly ideal performance characteristics (high intensity and purity) and is well-suited for clinical use. Six glioblastoma multiforme (GBM) patients were treated with NCT by infusion of the tumor-selective amino acid boronophenylalanine-fructose (BPA-F) at a dose of 14.0 g/m(2) body surface area over 90 min followed by irradiation with epithermal neutrons. Treatments were planned using NCTPlan and an accelerated version of the Monte Carlo radiation transport code MCNP 4B. Treatments were delivered in two fractions with two or three fields. Field order was reversed between fractions to equalize the average blood boron concentration between fields. The initial dose in the dose escalation study was 7.0 RBEGy, prescribed as the mean dose to the whole brain volume. This prescription dose was increased by 10% to 7.7 RBEGy in the second cohort of patients. A pharmacokinetic model was used to predict the blood boron concentration for determination of the required beam monitor units with good accuracy; differences between prescribed and delivered doses were 1.5% or less. Estimates of average tumor doses ranged from 33.7 to 83.4 RBEGy (median 57.8 RBEGy), a substantial improvement over our previous trial where the median value of the average tumor dose was 25.8 RBEGy.

  14. Preliminary Aspects of Language Course Evaluation

    ERIC Educational Resources Information Center

    Zohrabi, Mohammad

    2012-01-01

    Program and /or course evaluation is a process in which different types of data are collected systematically in order to study the virtues and weaknesses of a language instruction program. Program evaluation is, in fact, one of the essential aspects of any curriculum. It is a kind of quality control in which various aspects of an instructional…

  15. Preliminary Aspects of Language Course Evaluation

    ERIC Educational Resources Information Center

    Zohrabi, Mohammad

    2012-01-01

    Program and/or course evaluation is a process in which different types of data are collected systematically in order to study the virtues and weaknesses of a language instruction program. Program evaluation is, in fact, one of the essential aspects of any curriculum. It is a kind of quality control in which various aspects of an instructional…

  16. Dose evaluation of boron neutron capture synovectomy using the THOR epithermal neutron beam: a feasibility study

    NASA Astrophysics Data System (ADS)

    Wu, Jay; Chang, Shu-Jun; Chuang, Keh-Shih; Hsueh, Yen-Wan; Yeh, Kuan-Chuan; Wang, Jeng-Ning; Tsai, Wen-Pin

    2007-03-01

    Rheumatoid arthritis is one of the most common epidemic diseases in the world. For some patients, the treatment with steroids or nonsteroidal anti-inflammatory drugs is not effective, thus necessitating physical removal of the inflamed synovium. Alternative approaches other than surgery will provide appropriate disease control and improve the patient's quality of life. In this research, we evaluated the feasibility of conducting boron neutron capture synovectomy (BNCS) with the Tsing Hua open-pool reactor (THOR) as a neutron source. Monte Carlo simulations were performed with arthritic joint models and uncertainties were within 5%. The collimator, reflector and boron concentration were optimized to reduce the treatment time and normal tissue doses. For the knee joint, polyethylene with 40%-enriched Li2CO3 was used as the collimator material, and a rear reflector of 15 cm thick graphite and side reflector of 10 cm thick graphite were chosen. The optimized treatment time was 5.4 min for the parallel-opposed irradiation. For the finger joint, polymethyl methacrylate was used as the reflector material. The treatment time can be reduced to 3.1 min, while skin and bone doses can be effectively reduced by approximately 9% compared with treatment using the graphite reflector. We conclude that using THOR as a treatment modality for BNCS could be a feasible alternative in clinical practice.

  17. Preliminary evaluation of implantable MOSFET radiation dosimeters.

    PubMed

    Beddar, A S; Salehpour, M; Briere, T M; Hamidian, H; Gillin, M T

    2005-01-07

    In this paper, we report on measurements performed on a new prototype implantable radiation detector that uses metal-oxide semiconductor field effect transistors (MOSFETs) designed for in vivo dosimetry. The dosimeters, which are encapsulated in hermetically sealed glass cylinders, are used in an unbiased mode during irradiation, unlike other MOSFET detectors previously used in radiotherapy applications. They are powered by radio frequency telemetry for dose measurements, obviating the need for a power supply within each capsule. We have studied the dosimetric characteristics of these MOSFET detectors in vitro under irradiation from a 60Co source. The detectors show a dose reproducibility generally within 5% or better, with the main sources of error being temperature fluctuations occurring between the pre- and post-irradiation measurements as well as detector orientation. A better temperature-controlled environment leads to a reproducibility within 2%. Our preliminary in vitro results show clearly that true non-invasive in vivo dosimetry measurements are feasible and can be performed remotely using telemetric technology.

  18. Improving Natural Uranium Utilization By Using Thorium in Low Moderation PWRs - A Preliminary Neutronic Scoping Study

    SciTech Connect

    Gilles Youinou; Ignacio Somoza

    2010-10-01

    The Th-U fuel cycle is not quite self-sustainable when used in water-cooled reactors and with fuel burnups higher than a few thousand of MWd/t characteristic of CANDU reactors operating with a continuous refueling. For the other industrially mature water-cooled reactors (i.e. PWRs and BWRs) it is economically necessary that the fuel has enough reactivity to reach fuel burnups of the order of a few tens of thousand of MWd/t. In this particular case, an additional input of fissile material is necessary to complement the bred fissile U-233. This additional fissile material could be included in the form of Highly Enriched Uranium (HEU) at the fabrication of the Th-U fuel. The objective of this preliminary neutronic scoping study is to determine (1) how much HEU and, consequently, how much natural uranium is necessary in such Th-U fuel cycle with U recycling and (2) how much TRansUranics (TRU=Pu, Np, Am and Cm) are produced. These numbers are then compared with those of a standard UO2 PWR. The thorium reactors considered have a homogeneous hexagonal lattice made up of the same (Th-U)O2 pins. Furthermore, at this point, we are not considering the use of blankets inside or outside the core. The lattice pitch has been varied to estimate the effect of the water-to-fuel volume ratio, and light water as well as heavy water have been considered. For most cases, an average burnup at discharge of 45,000 MWd/t has been considered.

  19. Quantitative evaluation of bronchial enhancement: preliminary observations

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Godoy, Myrna C. B.; Schmidt, Bernhard

    2010-03-01

    It has been known for several years that airflow limitations in the small airways may be an important contributor to Chronic Obstructive Pulmonary Disease (COPD). Quantification of wall thickness has lately gained attention thanks to the use of high resolution CT, with novel approaches focusing on automated methods that can substitute for visual assessment [1, 2]. While increased thickening of the wall is considered evidence of inflammatory disease, we hypothesize that there may be additional ways to detect and quantify inflammation, specifically the uptake of contrast material. In this preliminary investigation, we selected patients with documented chronic airway inflammation, and for whom pre and post contrast datasets were available. On targeted reconstruction of right upper and lower lobes, we selected airways with no connections to surrounding structures, and used a modified Full-Width-Half-Max method for quantification of lumen diameter, wall thickness, and wall density. Matching airway locations on the pre- and postcontrast cases were compared. Airways from patients without airway disease served as a control. Results for the airway disease cases showed an average enhancement of 72 HU within the airway walls, with a standard deviation of 59 HU. In the control group the average enhancement was 16 HU with standard deviation of 22 HU. While this study is limited in number of cases, we hypothesize that quantification of contrast uptake is an additional factor to consider in assessing airway inflammation. At the same time we are currently investigating whether enhancement can be measured via a "contrast" map created with dual energy scanning, where a 3-value decomposition algorithm differentiates iodine from other materials. This technique would eliminate both the need for a pre-contrast scan, and the task of matching airway locations on pre- and post- scans.

  20. Preliminary study of neutron absorption by concrete with boron carbide addition

    SciTech Connect

    Abdullah, Yusof Yusof, Mohd Reusmaazran; Zali, Nurazila Mat; Ahmad, Megat Harun Al Rashid Megat; Yazid, Hafizal; Ariffin, Fatin Nabilah Tajul; Ahmad, Sahrim; Hamid, Roszilah; Mohamed, Abdul Aziz

    2014-02-12

    Concrete has become a conventional material in construction of nuclear reactor due to its properties like safety and low cost. Boron carbide was added as additives in the concrete construction as it has a good neutron absorption property. The sample preparation for concrete was produced with different weight percent of boron carbide powder content. The neutron absorption rate of these samples was determined by using a fast neutron source of Americium-241/Be (Am-Be 241) and detection with a portable backscattering neutron detector. Concrete with 20 wt % of boron carbide shows the lowest count of neutron transmitted and this indicates the most neutrons have been absorbed by the concrete. Higher boron carbide content may affect the concrete strength and other properties.

  1. Preliminary study of neutron absorption by concrete with boron carbide addition

    NASA Astrophysics Data System (ADS)

    Abdullah, Yusof; Ariffin, Fatin Nabilah Tajul; Hamid, Roszilah; Yusof, Mohd Reusmaazran; Zali, Nurazila Mat; Ahmad, Megat Harun Al Rashid Megat; Yazid, Hafizal; Ahmad, Sahrim; Mohamed, Abdul Aziz

    2014-02-01

    Concrete has become a conventional material in construction of nuclear reactor due to its properties like safety and low cost. Boron carbide was added as additives in the concrete construction as it has a good neutron absorption property. The sample preparation for concrete was produced with different weight percent of boron carbide powder content. The neutron absorption rate of these samples was determined by using a fast neutron source of Americium-241/Be (Am-Be 241) and detection with a portable backscattering neutron detector. Concrete with 20 wt % of boron carbide shows the lowest count of neutron transmitted and this indicates the most neutrons have been absorbed by the concrete. Higher boron carbide content may affect the concrete strength and other properties.

  2. Evaluation of Neutron Poison Materials for DOE SNF Disposal Systems

    SciTech Connect

    Vinson, D.W.; Caskey, G.R. Jr.; Sindelar, R.L.

    1998-09-01

    Aluminum-based spent nuclear fuel (Al-SNF) from foreign and domestic research reactors is being consolidated at the Savannah River Site (SRS) for ultimate disposal in the Mined Geologic Disposal System (MGDS). Most of the aluminum-based fuel material contains highly enriched uranium (HEU) (more than 20 percent 235U), which challenges the preclusion of criticality events for disposal periods exceeding 10,000 years. Recent criticality analyses have shown that the addition of neutron absorbing materials (poisons) is needed in waste packages containing DOE SNF canisters fully loaded with Al-SNF under flooded and degraded configurations to demonstrate compliance with the requirement that Keff less than 0.95. Compatibility of poison matrix materials and the Al-SNF, including their relative degradation rate and solubility, are important to maintain criticality control. An assessment of the viability of poison and matrix materials has been conducted, and an experimental corrosion program has been initiated to provide data on degradation rates of poison and matrix materials and Al-SNF materials under repository relevant vapor and aqueous environments. Initial testing includes Al6061, Type 316L stainless steel, and A516Gr55 in synthesized J-13 water vapor at 50 degrees C, 100 degrees C, and 200 degrees C and in condensate water vapor at 100 degrees C. Preliminary results are presented herein.

  3. A Preliminary Rubric Design to Evaluate Mixed Methods Research

    ERIC Educational Resources Information Center

    Burrows, Timothy J.

    2013-01-01

    With the increase in frequency of the use of mixed methods, both in research publications and in externally funded grants there are increasing calls for a set of standards to assess the quality of mixed methods research. The purpose of this mixed methods study was to conduct a multi-phase analysis to create a preliminary rubric to evaluate mixed…

  4. Formative Evaluation: Estimating Preliminary Outcomes and Testing Rival Explanations

    ERIC Educational Resources Information Center

    Henry, Gary T.; Smith, Adrienne A.; Kershaw, David C.; Zulli, Rebecca A.

    2013-01-01

    Performance-based accountability along with budget tightening has increased pressure on publicly funded organizations to develop and deliver programs that produce meaningful social benefits. As a result, there is increasing need to undertake formative evaluations that estimate preliminary program outcomes and identify promising program components…

  5. Preliminary technical and economic evaluation of vortex extraction devices

    SciTech Connect

    Kornreich, T. R.; Kottler, Jr., R. J.; Jennings, D. M.

    1980-04-01

    Two innovative vortex extraction devices - the Tornado Wind Energy System (TWES) and the Vortex Augmentor Concept (VAC) - are critically evaluated to provide a preliminary assessment of their technical and economic viability as compared to conventional horizontal axis wind energy systems. This assessment was carried out over a wide range of power output levels and augmentation ratios appropriate to each of the concepts.

  6. Connecticut Transit (CTTRANSIT) Fuel Cell Transit Bus: Preliminary Evaluation Results

    SciTech Connect

    Chandler, K.; Eudy, L.

    2008-10-01

    This report provides preliminary results from a National Renewable Energy Laboratory evaluation of a protoptye fuel cell transit bus operating at Connecticut Transit in Hartford. Included are descriptions of the planned fuel cell bus demonstration and equipment; early results and agency experience are also provided.

  7. Preliminary experiments on apparatus for in situ studies of microwave-driven reactions by small angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Whittaker, A. G.; Harrison, A.; Oakley, G. S.; Youngson, I. D.; Heenan, R. K.; King, S. M.

    2001-01-01

    In this article we describe apparatus for the study of the microwave-driven growth of particles in solution by in situ small angle neutron scattering (SANS). This apparatus has enabled the first preliminary experiments using microwave-activated in situ diffraction. We take iron oxide as the prototype system, but the technique may be extended to a wide variety of chemical reactions that deposit solids from solution. The key features of the apparatus are a microwave cavity with a modular construction that may be adapted to the geometric constraints of the diffractometer, and a computer-controlled microwave generator that may be set to maintain either constant pressure or temperature in the reaction vessel. In this particular piece of equipment the reaction vessel is adapted so that part of the sample fills a cell of identical construction to those commonly used in SANS measurements for optimal transmission of the neutron beam.

  8. Evaluation of the NDP (neutron diagnostic probe) system

    SciTech Connect

    Pentaleri, E.A.; Eisen, Y.Y.

    1990-12-01

    The neutron diagnostic probe (NDP), an explosive detection system developed by Consolidated Controls Corporation and based on the associated-alpha-particle technique, was evaluated. Although many problems were found with the prototype system that make it useless for most practical applications, the NDP system may be considered a successful proof-of-principle for the basic explosive detection system design. In addition to evaluating the design and performance of the present system, models were developed to estimate the performance that might reasonably be expected from full scale systems of different conceptual design. Specific examples involved various types of bulk and sheet explosives contained in a suitcase and a large crate. Also considered were the effects of innocuous materials surrounding explosives in different scenarios, including the deliberate use of shielding materials as a countermeasure to detection. 11 refs., 46 figs., 24 tabs.

  9. Evaluation of Neutron Resonance Cross Section Data at GELINA

    NASA Astrophysics Data System (ADS)

    Schillebeeckx, P.; Becker, B.; Capote, R.; Emiliani, F.; Guber, K.; Heyse, J.; Kauwenberghs, K.; Kopecky, S.; Lampoudis, C.; Massimi, C.; Mondelaers, W.; Moxon, M.; Noguere, G.; Plompen, A. J. M.; Pronyaev, V.; Siegler, P.; Sirakov, I.; Trkov, A.; Volev, K.; Zerovnik, G.

    2014-05-01

    Over the last decade, the EC-JRC-IRMM, in collaboration with other institutes such as INRNE Sofia (BG), INFN Bologna (IT), ORNL (USA), CEA Cadarache (FR) and CEA Saclay (FR), has made an intense effort to improve the quality of neutron-induced cross section data in the resonance region. These improvements relate to both the infrastructure of the facility and the measurement setup, and the data reduction and analysis procedures. As a result total and reaction cross section data in the resonance region with uncertainties better than 0.5 % and 2 %, respectively, can be produced together with evaluated data files for both the resolved and unresolved resonance region. The methodology to produce full ENDF compatible files, including covariances, is illustrated by the production of resolved resonance parameter files for 241Am, Cd and W and an evaluation for 197Au in the unresolved resonance region.

  10. Current Issues in Nuclear Data Evaluation Methodology: {sup 235}U Prompt Fission Neutron Spectra and Multiplicity for Thermal Neutrons

    SciTech Connect

    Trkov, A.; Capote, R.; Pronyaev, V.G.

    2015-01-15

    Issues in evaluation methodology of the prompt fission neutron spectra (PFNS) and neutron multiplicity for the thermal-neutron-induced fission of the {sup 235}U are discussed. The inconsistency between the experimental differential and integral data is addressed. By using differential data as ”shape data” good consistency was achieved between available sets of differential data. Integral dosimetry data have been used to define the PFNS slope at high outgoing neutron energies, where the quality of the differential data is poor. The inclusion into the fit of measured integral (spectrum-averaged) cross sections had a very small impact in the region where differential PFNS data are abundant and accurate, but removed the discrepancy with integral data at higher neutron emission energies. All experimental data are consistently fitted giving a PFNS average energy of 2.008 MeV. The impact on criticality prediction of the newly evaluated PFNS was tested. The highly enriched {sup 235}U solution assemblies with high leakage HEU-SOL-THERM-001 and HEU-SOL-THERM-009 benchmarks are the most sensitive to the PFNS. Criticality calculations for those solutions show a significant increase in reactivity if the average neutron energy of the fission neutrons is reduced from the ENDF/B-VI.5 value of 2.03 MeV. The proposed reduction of the PFNS average energy by 1.1% can be compensated by reducing the average number of neutrons per fission ν{sup ¯} at the thermal energy to the Gwin et al. measured value. The simple least-squares PFNS fit was confirmed by a more sophisticated combined fit of differential PFNS data for {sup 233,235}U, {sup 239}Pu and {sup 252}Cf nuclides with the generalised least-squares method using the GMA and GANDR codes.

  11. Current Issues in Nuclear Data Evaluation Methodology: 235U Prompt Fission Neutron Spectra and Multiplicity for Thermal Neutrons

    NASA Astrophysics Data System (ADS)

    Trkov, A.; Capote, R.; Pronyaev, V. G.

    2015-01-01

    Issues in evaluation methodology of the prompt fission neutron spectra (PFNS) and neutron multiplicity for the thermal-neutron-induced fission of the 235U are discussed. The inconsistency between the experimental differential and integral data is addressed. By using differential data as "shape data" good consistency was achieved between available sets of differential data. Integral dosimetry data have been used to define the PFNS slope at high outgoing neutron energies, where the quality of the differential data is poor. The inclusion into the fit of measured integral (spectrum-averaged) cross sections had a very small impact in the region where differential PFNS data are abundant and accurate, but removed the discrepancy with integral data at higher neutron emission energies. All experimental data are consistently fitted giving a PFNS average energy of 2.008 MeV. The impact on criticality prediction of the newly evaluated PFNS was tested. The highly enriched 235U solution assemblies with high leakage HEU-SOL-THERM-001 and HEU-SOL-THERM-009 benchmarks are the most sensitive to the PFNS. Criticality calculations for those solutions show a significant increase in reactivity if the average neutron energy of the fission neutrons is reduced from the ENDF/B-VI.5 value of 2.03 MeV. The proposed reduction of the PFNS average energy by 1.1% can be compensated by reducing the average number of neutrons per fission νbar at the thermal energy to the Gwin et al. measured value. The simple least-squares PFNS fit was confirmed by a more sophisticated combined fit of differential PFNS data for 233,235U, 239Pu and 252Cf nuclides with the generalised least-squares method using the GMA and GANDR codes.

  12. An Evaluation of Grazing-Incidence Optics for Neutron Imaging

    NASA Technical Reports Server (NTRS)

    Gubarev, M. V.; Ramsey, B. D.; Engelhaupt, D. E.; Burgess, J.; Mildner, D. F. R.

    2007-01-01

    The focusing capabilities of neutron imaging optic based on the Wolter-1 geometry have been successfully demonstrated with a beam of long wavelength neutrons with low angular divergence.. A test mirror was fabricated using an electroformed nickel replication process at Marshall Space Flight Center. The neutron current density gain at the focal spot of the mirror is found to be at least 8 for neutron wavelengths in the range from 6 to 20 A. Possible applications of the optics are briefly discussed.

  13. Dirhenium decacarbonyl-loaded PLLA nanoparticles: influence of neutron irradiation and preliminary in vivo administration by the TMT technique.

    PubMed

    Hamoudeh, Misara; Fessi, Hatem; Mehier, Henri; Faraj, Achraf Al; Canet-Soulas, Emmanuelle

    2008-02-04

    neutron irradiation, yielding an absorbed dose of 450kGy, can be a terminal method for nanoparticles sterilisation. Thereafter, in a preliminary in vivo experiment, superparamagnetic non radioactive nanoparticles loaded with Re(2)(CO)(10) and oleic-acid coated magnetite have been successfully injected into a mice animal model via targeted multi therapy (TMT) technique which would be our selected administration method for future in vivo studies. In conclusion, although some induced neutron irradiation damage to nanoparticles occurs, dirhenium decacarbonyl-loaded PLLA nanoparticles retain their chemical identity and remain almost as re-dispersible and injectable nanoparticles by the TMT technique. These nanoparticles represent a novel interesting candidate for local intra-tumoral radiotherapy.

  14. Further Evaluation of the Neutron Resonance Transmission Analysis (NRTA) Technique for Assaying Plutonium in Spent Fuel

    SciTech Connect

    J. W. Sterbentz; D. L. Chichester

    2011-09-01

    This is an end-of-year report (Fiscal Year (FY) 2011) for the second year of effort on a project funded by the National Nuclear Security Administration's Office of Nuclear Safeguards (NA-241). The goal of this project is to investigate the feasibility of using Neutron Resonance Transmission Analysis (NRTA) to assay plutonium in commercial light-water-reactor spent fuel. This project is part of a larger research effort within the Next-Generation Safeguards Initiative (NGSI) to evaluate methods for assaying plutonium in spent fuel, the Plutonium Assay Challenge. The second-year goals for this project included: (1) assessing the neutron source strength needed for the NRTA technique, (2) estimating count times, (3) assessing the effect of temperature on the transmitted signal, (4) estimating plutonium content in a spent fuel assembly, (5) providing a preliminary assessment of the neutron detectors, and (6) documenting this work in an end of the year report (this report). Research teams at Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL), Pacific Northwest National Laboratory (PNNL), and at several universities are also working to investigate plutonium assay methods for spent-fuel safeguards. While the NRTA technique is well proven in the scientific literature for assaying individual spent fuel pins, it is a newcomer to the current NGSI efforts studying Pu assay method techniques having just started in March 2010; several analytical techniques have been under investigation within this program for two to three years or more. This report summarizes work performed over a nine month period from January-September 2011 and is to be considered a follow-on or add-on report to our previous published summary report from December 2010 (INL/EXT-10-20620).

  15. Hydrogen-enrichment-concept preliminary evaluation

    NASA Technical Reports Server (NTRS)

    Ecklund, E. E.

    1975-01-01

    A hydrogen-enriched fuels concept for automobiles is described and evaluated in terms of fuel consumption and engine exhaust emissions through multicylinder (V-8) automotive engine/hydrogen generator tests, single cylinder research engine (CFR) tests, and hydrogen-generator characterization tests. Analytical predictions are made of the fuel consumption and NO/sub x/ emissions which would result from anticipated engine improvements. The hydrogen-gas generator, which was tested to quantify its thermodynamic input-output relationships was used for integrated testing of the V-8 engine and generator.

  16. Preliminary pharmacological evaluation of enantiomeric morphinans.

    PubMed

    Sromek, Anna W; Provencher, Brian A; Russell, Shayla; Chartoff, Elena; Knapp, Brian I; Bidlack, Jean M; Neumeyer, John L

    2014-02-19

    A series of levo- and dextromorphinan pairs have been synthesized and evaluated for their affinities to the mu, kappa, and delta opioid receptors, the N-methyl-D-aspartate (NMDA) channel, and sigma 1 and 2 receptors. It was found that levo isomers tended to have higher affinities at the opioid receptors and moderate to high affinities to the NMDA and sigma receptors, while dextro isomers tended to have lower affinities to the opioid receptors but comparatively higher affinities to the NMDA and sigma receptors. This series of compounds have interesting and complex pharmacological profiles, and merit further investigation as potential therapies for drug abuse treatment.

  17. Neutron-diffraction characterization of tungsten-nickel-iron alloys. Preliminary technical report, 1984-1985

    SciTech Connect

    Prask, H.J.; Choi, C.S.

    1986-02-01

    Neutron diffraction and small-angle scattering were employed to elucidate the effect of strain aging on macroscopic properties of tungsten-nickel-iron (W-.07Ni-.03Fe) alloys. The neutron measurements indicate that strain aging causes reduction and redistribution of residual stresses induced by swaging, accompanied by void/precipitate evolution.

  18. Preliminary measurements of neutrons from the D-D reaction in the COMPASS tokamak

    SciTech Connect

    Dankowski, J. Kurowski, A.; Twarog, D.; Janky, F.; Stockel, J.

    2014-08-21

    Recent results of measured fast neutrons created in the D-D reaction on the COMPASS tokamak during ohmic discharges are presented in this paper. Two different type detectors were used during experiment. He-3 detectors and bubble detectors as a support. The measurements are an introduction for neutron diagnostic on tokamak COMPASS and monitoring neutrons during discharges with Neutral Beam Injection (NBI). The He-3 counters and bubble detectors were located in two positions near tokamak vacuum chamber at a distance less than 40 cm to the centre of plasma. The neutrons flux was observed in ohmic discharges. However, analysis of our results does not indicate any clear source of neutrons production during ohmic discharges.

  19. Preliminary evaluation of hybrid titanium composite laminates

    NASA Technical Reports Server (NTRS)

    Miller, J. L.; Progar, D. J.; Johnson, W. S.; St.clair, T. L.

    1994-01-01

    In this study, the mechanical response of hybrid titanium composite laminates (HTCL) was evaluated at room and elevated temperatures. Also, the use of an elastic-plastic laminate analysis program for predicting the tensile response from constituent properties was verified. The improvement in mechanical properties achieved by the laminates was assessed by comparing the results of static strength and constant amplitude fatigue tests to those for monolithic titanium sheet. Two HTCL were fabricated with different fiber volume fractions, resin layer thicknesses, and resins. One panel was thicker and was more poorly bonded in comparison to other. Consequently, the former had a lower tensile strength, while fewer cracks grew in this panel and at a slower rate. Both panels showed an improvement in fatigue life of almost two orders of magnitude. The model predictions were also in good agreement with the experimental results for both HTCL panels.

  20. Technology and outpatient review: a preliminary evaluation.

    PubMed

    Bergman, A; Henderson, M; Cline, J L

    1990-06-01

    Most health care utilization and cost control programs focus on inpatient care or on high-cost, catastrophic illnesses or injuries. Recently, however, Parkside Health Management Corporation has developed a utilization review program that targets treatments and high-technology procedures performed primarily in an outpatient setting, as well as specific inpatient procedures not included in other review programs. These include chiropractic, podiatric, and physical therapy treatments; cesarean section; and endoscopy, ultrasound in pregnancy, and lithotripsy. The treatments/procedures examined in this program, called Technology and Outpatient Review (TOR), account for approximately 6% of claims expenses. Bigel Institute for Health Policy researchers are evaluating a pilot test to determine TOR's effect on health care costs and utilization, appropriateness, and patient satisfaction.

  1. Holmium:YAG laser stapedotomy: preliminary evaluation

    NASA Astrophysics Data System (ADS)

    Stubig, Ingrid M.; Reder, Paul A.; Facer, G. W.; Rylander, Henry G.; Welch, Ashley J.

    1993-07-01

    This study investigated the use of a pulsed Holmium:YAG ((lambda) equals 2.09 micrometers ) laser- fiber microsurgical system for laser stapedotomy. This system ablates human stapes bones effectively with minimal thermal damage. The study was designed to determine the effectiveness of the Ho:YAG laser (Schwartz Electro Optics, Inc., Orlando, FL) for stapedotomy and to evaluate temperature changes within the cochlea during the ablation process. Human cadaveric temporal bones were obtained and the stapes portion of the ossicular chain was removed. A 200 micrometers diameter low OH quartz fiber was used to irradiate these stapes bones in an air environment. The laser was pulsed at 2 Hz, 250 microsecond(s) ec pulse width and an irradiance range of 100 - 240 J/cm2 was used to ablate holes in the stapes footplate. The resultant stapedotomies created had smooth 300 micrometers diameter holes with a minimum of circumferential charring. Animal studies in-vivo were carried out in chinchillas to determine the caloric spread within the cochlea. A 0.075 mm Type T thermocouple was placed in the round window. Average temperature change during irradiation of the stapes footplate recorded in the round window was 3.6 degree(s)C. The data suggest that stapedotomy using the Ho:YAG laser can result in a controlled ablation of the stapes footplate with minimal thermal damage to the surrounding stapes. Optical coupling using fiberoptic silica fibers is an ideal method for delivering laser energy to the stapes during stapedotomy.

  2. Evaluation of the neutron spectrum and dose assessment around the venus reactor.

    PubMed

    Coeck, Michèle; Vermeersch, Fernand; Vanhavere, Filip

    2005-01-01

    An assessment of the neutron field near the VENUS reactor is made in order to evaluate the neutron dose to the operators, particularly in an area near the reactor shielding and in the control room. Therefore, a full MCNPX model of the shielding geometry was developed. The source term used in the simulation is derived from a criticality calculation done beforehand. Calculations are compared to routine neutron dose rate measurements and show good agreement. The MCNPX model developed easily allows core adaptations in order to evaluate the effect of future core configuration on the neutron dose to the operators.

  3. Skylab neutron environment experiment (Science Demonstration SD-34 (TV108)). Description and preliminary results

    NASA Technical Reports Server (NTRS)

    Fishman, G. J.

    1974-01-01

    Neutron and proton induced radioactivity at various locations within Skylab were measured. Samples of five metals were formed into activation packets and deployed at the following locations on the Skylab 4 mission: orbital workshop film vault, water storage tank, and two opposing orbital workshop internal locations. Radioactive nuclides were produced in the packets by nuclear interactions of high-energy protons and secondary neutrons within Skylab. Low-level gamma ray spectroscopy measurements were made on the returned packets to determine the incident neutron and proton fluxes and spectra and their variations with mass distribution.

  4. Characteristic evaluation of a Lithium-6 loaded neutron coincidence spectrometer.

    PubMed

    Hayashi, M; Kaku, D; Watanabe, Y; Sagara, K

    2007-01-01

    Characteristics of a (6)Li-loaded neutron coincidence spectrometer were investigated from both measurements and Monte Carlo simulations. The spectrometer consists of three (6)Li-glass scintillators embedded in a liquid organic scintillator BC-501A, which can detect selectively neutrons that deposit the total energy in the BC-501A using a coincidence signal generated from the capture event of thermalised neutrons in the (6)Li-glass scintillators. The relative efficiency and the energy response were measured using 4.7, 7.2 and 9.0 MeV monoenergetic neutrons. The measured ones were compared with the Monte Carlo calculations performed by combining the neutron transport code PHITS and the scintillator response calculation code SCINFUL. The experimental light output spectra were in good agreement with the calculated ones in shape. The energy dependence of the detection efficiency was reproduced by the calculation. The response matrices for 1-10 MeV neutrons were finally obtained.

  5. Evaluation of H*(10) using the developed spherical type neutron dose monitor.

    PubMed

    Bhuiya, S H; Yamanishi, H; Uda, T

    2010-10-01

    An instrument for evaluating the neutron ambient dose equivalent has been developed. It has the characteristic of uniform response to wide energy of neutrons. The monitor is four-layered spherically shaped, based on moderation and absorption of neutrons. Neutron dose can be evaluated from the linear combination of three specific responses of thermoluminescent dosimeters (TLDs), which are located at three depths in the moderator. TLDs were arranged between layers of two consecutive depths on 12 radial axes at even intervals so that the monitor is equally sensitive to all directions of neutrons. In order to verify the usefulness of dose evaluation by the monitor, irradiation experiments were conducted at the FRS, JAEA. The D2O-moderated 252Cf was used for the calibration of the monitor. Experiments were also conducted by using two neutron sources of 252Cf bare and 241Am-Be. As a result, the evaluated dose for each irradiation was obtained close to the actual irradiated dose. It was confirmed that the method of dose evaluation by the developed monitor can be applied to practical neutron fields where the distance of neutron source is unknown.

  6. Neutron collar calibration and evaluation for assay of LWR fuel assemblies containing burnable neutron absorbers

    SciTech Connect

    Henriksen, P.W.; Menlove, H.O.; Stewart, J.E.; Qiao, S.Z.; Wenz, T.R. ); Verrecchia, G.P.D. . Safeguards Directorate)

    1990-11-01

    The neutron coincidence collar is used to verify the uranium content in light water reactor fuel assemblies. An AmLi neutron source actively interrogates the fuel assembly to measure the {sup 235}U content and the {sup 238}U content can be verified from a passive neutron coincidence measurement. This report gives the collar calibration data for pressurized water reactor (PWR) and boiling water reactor (BWR) fuel assemblies both with and without cadmium liners. Calibration curves and correction factors are presented for neutron absorbers (burnable poisons) and various fuel assembly sizes. The data were collected using the Los Alamos BWR and PWR test assemblies as well as fuel assemblies from several fuel fabrication facilities. 11 refs., 15 figs., 14 tabs.

  7. Preliminary evaluations of a spoken web enabled care management platform.

    PubMed

    Padman, Rema; Beam, Erika; Szewczyk, Rachel

    2013-01-01

    Telephones are a ubiquitous and widely accepted technology worldwide. The low ownership cost, simple user interface, intuitive voice-based access and long history contribute to the wide-spread use and success of telephones, and more recently, that of mobile phones. This study reports on our preliminary efforts to leverage this technology to bridge disparities in the access to and delivery of personalized health and wellness care by developing and evaluating a Spoken Web enabled Care Management solution. Early results with two proxy evaluations and a few visually impaired users highlight both the potential and challenges associated with this novel, voice-enabled healthcare delivery solution.

  8. PGNAA system preliminary design and measurement of In-Hospital Neutron Irradiator for boron concentration measurement.

    PubMed

    Zhang, Zizhu; Chong, Yizheng; Chen, Xinru; Jin, Congjun; Yang, Lijun; Liu, Tong

    2015-12-01

    A prompt gamma neutron activation analysis (PGNAA) system has been recently developed at the 30-kW research reactor In-Hospital Neutron Irradiator (IHNI) in Beijing. Neutrons from the specially designed thermal neutron beam were used. The thermal flux of this beam is 3.08×10(6) cm(-2) s(-1) at a full reactor power of 30 kW. The PGNAA system consists of an n-type high-purity germanium (HPGe) detector of 40% efficiency, a digital spectrometer, and a shielding part. For both the detector shielding part and the neutron beam shielding part, the inner layer is composed of (6)Li2CO3 powder and the outer layer lead. The boron-10 sensitivity of the PGNAA system is approximately 2.5 cps/ppm. Two calibration curves were produced for the 1-10 ppm and 10-50 ppm samples. The measurement results of the control samples were in accordance with the inductively coupled plasma atomic emission spectroscopy (ICP-AES) results.

  9. DOE personnel neutron dosimetry evaluation and upgrade program

    SciTech Connect

    Faust, L.G.; Stroud, C.M.; Vallario, E.J.

    1988-10-01

    The US Department of Energy (DOE) sponsors an extensive research program to improve the methods, dosimeters, and instruments available to DOE facilities for measuring neutron dose and assessing its effects on the work force. The Total Dose Meter was recently developed for measuring in real time the adsorbed dose of mixed neutron and gamma radiation and for calculating the dose equivalent. The Field Neutron Spectrometer was developed to provide a portable instrument for determining neutron spectra in the workplace for flux-to-dose equivalent conversion and quality factor calculation. The Combination Thermoluminescence/Track Etch Dosimeter (TLD/TED) was developed to extend the effective neutron energy range of the conventional TLDs to improve detection of fast-energy neutrons. An Optically Stimulated Luminescence Dosimeter is presently being developed for application to gamma, neutron, and beta radiation. An Effective Dose Equivalent System is being developed to provide guidance in implementing the January 1987 Presidential Directive to determine effective dose equivalent. Superheated Drop Detectors are being investigated for their potential as real time neutron dosimeters. This paper includes discussions of these improvements brought about by the DOE research program. 3 refs.

  10. Stability evaluation and correction of a pulsed neutron generator prompt gamma activation analysis system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Source output stability is important for accurate measurement in prompt gamma neutron activation. This is especially true when measuring low-concentration elements such as in vivo nitrogen (~2.5% of body weight). We evaluated the stability of the compact DT neutron generator within an in vivo nitrog...

  11. 78 FR 8522 - Chlorpyrifos Registration Review; Preliminary Evaluation of the Potential Risk From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... AGENCY Chlorpyrifos Registration Review; Preliminary Evaluation of the Potential Risk From Volatilization... review of chlorpyrifos and opens a public comment period on this document. Registration review is EPA's... has completed a preliminary volatilization assessment for chlorpyrifos uses. After reviewing...

  12. Preliminary time-of-flight neutron diffraction study on diisopropyl fluorophosphatase (DFPase) from Loligo vulgaris

    SciTech Connect

    Blum, Marc-Michael; Koglin, Alexander; Rüterjans, Heinz; Schoenborn, Benno; Langan, Paul; Chen, Julian C.-H.

    2007-01-01

    Diisopropyl fluorophosphatase (DFPase) effectively hydrolyzes a number of organophosphorus nerve agents, including sarin, cyclohexylsarin, soman and tabun. Neutron diffraction data have been collected from DFPase crystals to 2.2 Å resolution in an effort to gain further insight into the mechanism of this enzyme. The enzyme diisopropyl fluorophosphatase (DFPase) from Loligo vulgaris is capable of decontaminating a wide variety of toxic organophosphorus nerve agents. DFPase is structurally related to a number of enzymes, such as the medically important paraoxonase (PON). In order to investigate the reaction mechanism of this phosphotriesterase and to elucidate the protonation state of the active-site residues, large-sized crystals of DFPase have been prepared for neutron diffraction studies. Available H atoms have been exchanged through vapour diffusion against D{sub 2}O-containing mother liquor in the capillary. A neutron data set has been collected to 2.2 Å resolution on a relatively small (0.43 mm{sup 3}) crystal at the spallation source in Los Alamos. The sample size and asymmetric unit requirements for the feasibility of neutron diffraction studies are summarized.

  13. Preliminary evaluation of alternative ethanol/water separation processes

    SciTech Connect

    Eakin, D.E.; Donovan, J.M.; Cysewski, G.R.; Petty, S.E.; Maxham, J.V.

    1981-05-01

    Preliminary evaluation indicates that separation of ethanol and water can be accomplished with less energy than is now needed in conventional distillation processes. The state of development for these methods varies from laboratory investigation to commercially available processes. The processes investigated were categorized by type of separation depending on their ability to achieve varying degrees of ethanol/water separation. The following methods were investigated: ethanol extraction with CO/sub 2/ (the A.D. Little process); solvent extraction of ethanol; vacuum distillation; vapor recompression distillation; dehydration with fermentable grains; low temperature blending with gasoline; molecular sieve adsorption; and reverse osmosis.

  14. Improvement of Neutron/gamma Field Evaluation for Restart of Jmtr

    NASA Astrophysics Data System (ADS)

    Nagao, Yoshiharu; Niimi, Motoji; Kawamura, Hiroshi; Iguchi, Tetsuo

    2009-08-01

    The calculated neutron flux/fluence was verified against measurements of irradiated fluence monitors. With regard to gamma dose, calculated gamma heating rates were verified against measurements of the nuclear heating evaluation capsule which was developed in order to measure the nuclear heating rate. It was confirmed that the calculated fast and thermal neutron flux/fluence agreed with measurements within ±10%, ±30%, respectively, and the calculated gamma dose agreed within -3 ~ +21%. As the results of sensitive analysis, it was confirmed that difference of thermal S(α,β) libraries was not did not have effect on the evaluation of thermal neutron fluxes.

  15. Preliminary analysis of irradiation effects on CLAM after low dose neutron irradiation

    NASA Astrophysics Data System (ADS)

    Peng, Lei; Huang, Qunying; Li, Chunjing; Liu, Shaojun

    2009-04-01

    To investigate the irradiation effects on a new version of reduced activation ferritic/martensitic steels (RAFMs) i.e. China Low Activation Martensitic steel (CLAM), neutron irradiation experiments has been being carried out under wide collaboration in China and overseas. In this paper, the mechanical properties of CLAM heats 0603A, 0408B, and 0408D were investigated before and after neutron irradiation to ˜0.02 dpa at 250 °C. The test results showed that ultimate strength and yield stress of CLAM HEAT 0603A increased about 10-30 MPa and ductile to brittle transition temperature (DBTT) shift was about 5 °C. For CLAM heats 0408B and 0408D, ultimate strength and yield stress increased about 80-150 MPa.

  16. Preliminary neutron diffraction analysis of challenging human manganese superoxide dismutase crystals.

    PubMed

    Azadmanesh, Jahaun; Trickel, Scott R; Weiss, Kevin L; Coates, Leighton; Borgstahl, Gloria E O

    2017-04-01

    Superoxide dismutases (SODs) are enzymes that protect against oxidative stress by dismutation of superoxide into oxygen and hydrogen peroxide through cyclic reduction and oxidation of the active-site metal. The complete enzymatic mechanisms of SODs are unknown since data on the positions of hydrogen are limited. Here, methods are presented for large crystal growth and neutron data collection of human manganese SOD (MnSOD) using perdeuteration and the MaNDi beamline at Oak Ridge National Laboratory. The crystal from which the human MnSOD data set was obtained is the crystal with the largest unit-cell edge (240 Å) from which data have been collected via neutron diffraction to sufficient resolution (2.30 Å) where hydrogen positions can be observed.

  17. Crystallization and preliminary neutron diffraction experiment of human farnesyl pyrophosphate synthase complexed with risedronate

    PubMed Central

    Yokoyama, Takeshi; Ostermann, Andreas; Mizuguchi, Mineyuki; Niimura, Nobuo; Schrader, Tobias E.; Tanaka, Ichiro

    2014-01-01

    Nitrogen-containing bisphosphonates (N-BPs), such as risedronate and zoledronate, are currently used as a clinical drug for bone-resorption diseases and are potent inhibitors of farnesyl pyrophosphate synthase (FPPS). X-ray crystallographic analyses of FPPS with N-BPs have revealed that N-BPs bind to FPPS with three magnesium ions and several water molecules. To understand the structural characteristics of N-BPs bound to FPPS, including H atoms and hydration by water, neutron diffraction studies were initiated using BIODIFF at the Heinz Maier-Leibnitz Zentrum (MLZ). FPPS–risedronate complex crystals of approximate dimensions 2.8 × 2.5 × 1.5 mm (∼3.5 mm3) were obtained by repeated macro-seeding. Monochromatic neutron diffraction data were collected to 2.4 Å resolution with 98.4% overall completeness. Here, the first successful neutron data collection from FPPS in complex with N-BPs is reported. PMID:24699741

  18. Crystallization of porcine pancreatic elastase and a preliminary neutron diffraction experiment

    SciTech Connect

    Kinoshita, Takayoshi; Tamada, Taro; Imai, Keisuke; Kurihara, Kazuo; Ohhara, Takashi; Tada, Toshiji; Kuroki, Ryota

    2007-04-01

    To investigate the structural characteristics of a covalent inhibitor bound to porcine pancreatic elastase (PPE), including H atoms and hydration by water, a crystal of porcine pancreatic elastase with its inhibitor was grown to a size of 1.6 mm{sup 3} for neutron diffraction study. The crystal diffracted to 2.3 Å resolution with sufficient quality for further structure determination owing to the similar atomic scattering properties of deuterium and carbon. Porcine pancreatic elastase (PPE) resembles the attractive drug target leukocyte elastase, which has been implicated in a number of inflammatory disorders. In order to investigate the structural characteristics of a covalent inhibitor bound to PPE, including H atoms and the hydration by water, a single crystal of PPE for neutron diffraction study was grown in D{sub 2}O containing 0.2 M sodium sulfate (pD 5.0) using the sitting-drop vapour-diffusion method. The crystal was grown to a size of 1.6 mm{sup 3} by repeated macroseeding. Neutron diffraction data were collected at room temperature using a BIX-3 diffractometer at the JRR-3 research reactor of the Japan Atomic Energy Agency (JAEA). The data set was integrated and scaled to 2.3 Å resolution in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 51.2, b = 57.8, c = 75.6 Å.

  19. Crystallization and preliminary neutron diffraction experiment of human farnesyl pyrophosphate synthase complexed with risedronate.

    PubMed

    Yokoyama, Takeshi; Ostermann, Andreas; Mizuguchi, Mineyuki; Niimura, Nobuo; Schrader, Tobias E; Tanaka, Ichiro

    2014-04-01

    Nitrogen-containing bisphosphonates (N-BPs), such as risedronate and zoledronate, are currently used as a clinical drug for bone-resorption diseases and are potent inhibitors of farnesyl pyrophosphate synthase (FPPS). X-ray crystallographic analyses of FPPS with N-BPs have revealed that N-BPs bind to FPPS with three magnesium ions and several water molecules. To understand the structural characteristics of N-BPs bound to FPPS, including H atoms and hydration by water, neutron diffraction studies were initiated using BIODIFF at the Heinz Maier-Leibnitz Zentrum (MLZ). FPPS-risedronate complex crystals of approximate dimensions 2.8 × 2.5 × 1.5 mm (∼3.5 mm(3)) were obtained by repeated macro-seeding. Monochromatic neutron diffraction data were collected to 2.4 Å resolution with 98.4% overall completeness. Here, the first successful neutron data collection from FPPS in complex with N-BPs is reported.

  20. Preliminary nondestructive evaluation manual for the space shuttle. [preliminary nondestructive evaluation

    NASA Technical Reports Server (NTRS)

    Pless, W. M.

    1974-01-01

    Nondestructive evaluation (NDE) requirements are presented for some 134 potential fracture-critical structural areas identified, for the entire space shuttle vehicle system, as those possibly needing inspection during refurbishment/turnaround and prelaunch operations. The requirements include critical area and defect descriptions, access factors, recommended NDE techniques, and descriptive artwork. Requirements discussed include: Orbiter structure, external tank, solid rocket booster, and thermal protection system (development area).

  1. Historical Evaluation of Film Badge Dosimetry Y-12 Plant: Part 2–Neutron Radiation ORAUT-OTIB-0045

    SciTech Connect

    Kerr GD, Frome EL, Watkins JP, Tankersley WG

    2009-12-14

    A summary of the major neutron sources involved in radiation exposures to Y-12 workers is presented in this TIB. Graphical methods are used to evaluate available neutron dose data from quarterly exposures to Y-12 workers and to determine how the data could be used to derive neutron-to-gamma dose ratios for dose reconstruction purposes. This TIB provides estimates of neutron-to-gamma dose ratios for specific departments and a default value for the neutron-to-gamma dose ratio based on the pooled neutron dose data for all Y-12 departments.

  2. Evaluation of absorbed dose in Gadolinium neutron capture therapy

    NASA Astrophysics Data System (ADS)

    Abdullaeva, Gayane; Djuraeva, Gulnara; Kim, Andrey; Koblik, Yuriy; Kulabdullaev, Gairatulla; Rakhmonov, Turdimukhammad; Saytjanov, Shavkat

    2015-02-01

    Gadolinium neutron capture therapy (GdNCT) is used for treatment of radioresistant malignant tumors. The absorbed dose in GdNCT can be divided into four primary dose components: thermal neutron, fast neutron, photon and natural gadolinium doses. The most significant is the dose created by natural gadolinium. The amount of gadolinium at the irradiated region is changeable and depends on the gadolinium delivery agent and on the structure of the location where the agent is injected. To de- fine the time dependence of the gadolinium concentration ρ(t) in the irradiated region the pharmacokinetics of gadolinium delivery agent (Magnevist) was studied at intratumoral injection in mice and intramuscular injection in rats. A polynomial approximation was applied to the experimental data and the influence of ρ(t) on the relative change of the absorbed dose of gadolinium was studied.

  3. Preliminary Neutronics Analysis of the ITER Toroidal Interferometer and Polarimeter Diagnostic Corner Cube Retroreflectors

    SciTech Connect

    Tresemer, K. R.

    2015-07-01

    ITER is an international project under construction in France that will demonstrate nuclear fusion at a power plant-relevant scale. The Toroidal Interferometer and Polarimeter (TIP) Diagnostic will be used to measure the plasma electron line density along 5 laser-beam chords. This line-averaged density measurement will be input to the ITER feedback-control system. The TIP is considered the primary diagnostic for these measurements, which are needed for basic ITER machine control. Therefore, system reliability & accuracy is a critical element in TIP’s design. There are two major challenges to the reliability of the TIP system. First is the survivability and performance of in-vessel optics and second is maintaining optical alignment over long optical paths and large vessel movements. Both of these issues greatly depend on minimizing the overall distortion due to neutron & gamma heating of the Corner Cube Retroreflectors (CCRs). These are small optical mirrors embedded in five first wall locations around the vacuum vessel, corresponding to certain plasma tangency radii. During the development of the design and location of these CCRs, several iterations of neutronics analyses were performed to determine and minimize the total distortion due to nuclear heating of the CCRs. The CCR corresponding to TIP Channel 2 was chosen for analysis as a good middle-road case, being an average distance from the plasma (of the five channels) and having moderate neutron shielding from its blanket shield housing. Results show that Channel 2 meets the requirements of the TIP Diagnostic, but barely. These results suggest other CCRs might be at risk of exceeding thermal deformation due to nuclear heating.

  4. An Evaluation of Grazing-Incidence Optics for Neutron Imaging

    NASA Technical Reports Server (NTRS)

    Gubarev, M. V.

    2007-01-01

    The refractive index for most materials is slightly less than unity, which opens an opportunity to develop the grazing incidence neutron imaging optics. The ideal material for the optics would be natural nickel and its isotopes. Marshall Space Flight Center (MSFC) has active development program on the nickel replicated optics for use in x-ray astronomy. Brief status report on the program is presented. The results of the neutron focusing optic test carried by the MSFC team at National Institute of Standards and Technology (NIST) are also presented. Possible applications of the optics are briefly discussed.

  5. Neutron nuclear data evaluation of actinide nuclei for CENDL-3.1

    NASA Astrophysics Data System (ADS)

    Chen, Guo-Chang; Cao, Wen-Tian; Yu, Bao-Sheng; Tang, Guo-You; Shi, Zhao-Min; Tao, Xi

    2012-09-01

    New evaluations for several actinide nuclei of the third version of Chinese Evaluated Nuclear Data Library for Neutron Reaction Data (CENDL-3.1) have been completed and released. The evaluation is for all neutron induced reactions with uranium, neptunium, plutonium and americium in the mass range A = 232-241, 236-239, 236-246 and 240-244, respectively, and cover the incident neutron energy up to 20 MeV. In the present evaluation, much more effort was devoted to improving the reliability of the evaluated nuclear data for available new measured data, especially scarce or absent experimental data. A general description for the evaluation of several actinides' data is presented.

  6. Preliminary results of fast neutron treatments in carcinoma of the pancreas

    NASA Technical Reports Server (NTRS)

    Gahbauer, R.; Koh, K. Y.; Rodriguez-Antunez, A.; Jelden, G. L.; Turco, R. F.; Horton, J.; Bukowski, R.; Reimer, R.; Blue, J.; Roberts, W.

    1980-01-01

    A group of 30 patients with adenocarcinoma of the pancreas including some patients with very advanced disease, were treated with the so-called mixed beam modality employing photon treatments three times per week and neutron treatments twice a week. Two hundred Rads or equivalent Rads (RBE 3.3) were given in daily fractions aiming at a total dose of 6000 Rads in 6 to 8 weeks. The treatments were well tolerated and significant palliation was achieved in 26 to 30 cases. Twelve months survival was 33 percent with a median survival of 7 months or 210 days. Treatment techniques and localization procedures are discussed.

  7. Results from Preliminary Checks on AmBe Neutron Source Number 71

    DTIC Science & Technology

    2011-02-01

    1 2. BACKGROUND INFORMATION ON AMERICIUM -BERYLLIUM ...................... 1 3. METHOD...Background Information on Americium -Beryllium AmBe sources produce neutrons through the Be(,n) interaction, where an alpha particle (i.e. Helium nucleus...UNCLASSIFIED DSTO-TN-1003 241Am95  237Np93 + 42 9Be4 + 42  12C6 +1n0 +  Americium -241 used in the AmBe source has a half-life of 432.2

  8. Pharmacokinetics and preliminary safety evaluation of azithromycin in adult horses.

    PubMed

    Leclere, M; Magdesian, K G; Cole, C A; Szabo, N J; Ruby, R E; Rhodes, D M; Edman, J; Vale, A; Wilson, W D; Tell, L A

    2012-12-01

    Azithromycin is widely used in foals but has not been studied in adult horses. The goals of this study were to determine the pharmacokinetic profile and to make a preliminary assessment of the safety of azithromycin in adult horses. Azithromycin was administered intravenously (5 mg/kg) and intragastrically (10 mg/kg) to six healthy mares in a crossover design. Serial plasma samples, blood neutrophils, and pulmonary macrophages were collected for the measurement of azithromycin concentrations. Azithromycin was also administered orally (10 mg/kg) once a day for 5 days to five healthy mares for preliminary evaluation of safety in adult horses. The bioavailability of azithromycin following intragastric administration was 45 ± 12%. Concentrations within peripheral neutrophils and bronchoalveolar macrophages were several fold higher than that of plasma. Mild decreases in appetite (n = 3) and alterations in fecal consistency (n = 3) were noted following repeated oral administration. The pharmacokinetic profiles of azithromycin in adult horses, especially the slow elimination rate and intraneutrophil and intrapulmonary macrophage accumulation, demonstrate that it is conducive to use in this age group. Because of the gastrointestinal alterations noted, further studies are warranted before azithromycin can be recommended for use in adult horses.

  9. Evaluation of the 239Pu prompt fission neutron spectrum induced by neutrons of 500 keV and associated covariances

    NASA Astrophysics Data System (ADS)

    Neudecker, D.; Talou, P.; Kawano, T.; Smith, D. L.; Capote, R.; Rising, M. E.; Kahler, A. C.

    2015-08-01

    We present evaluations of the prompt fission neutron spectrum (PFNS) of 239Pu induced by 500 keV neutrons, and associated covariances. In a previous evaluation by Talou et al. (2010), surprisingly low evaluated uncertainties were obtained, partly due to simplifying assumptions in the quantification of uncertainties from experiment and model. Therefore, special emphasis is placed here on a thorough uncertainty quantification of experimental data and of the Los Alamos model predicted values entering the evaluation. In addition, the Los Alamos model was extended and an evaluation technique was employed that takes into account the qualitative differences between normalized model predicted values and experimental shape data. These improvements lead to changes in the evaluated PFNS and overall larger evaluated uncertainties than in the previous work. However, these evaluated uncertainties are still smaller than those obtained in a statistical analysis using experimental information only, due to strong model correlations. Hence, suggestions to estimate model defect uncertainties are presented, which lead to more reasonable evaluated uncertainties. The calculated keff of selected criticality benchmarks obtained with these new evaluations agree with each other within their uncertainties despite the different approaches to estimate model defect uncertainties. The keff one standard deviations overlap with some of those obtained using ENDF/B-VII.1, albeit their mean values are further away from unity. Spectral indexes for the Jezebel critical assembly calculated with the newly evaluated PFNS agree with the experimental data for selected (n,γ) and (n,f) reactions, and show improvements for high-energy threshold (n,2n) reactions compared to ENDF/B-VII.1.

  10. Preliminary Neutronics Design and Analysis of D2O Cooled High Conversion PWRs

    SciTech Connect

    Hikaru Hiruta; Gilles Youinou

    2012-09-01

    This report presents a neutronics analysis of tight-pitch D2O-cooled PWRs loaded with MOX fuel and focuses essentially on the Pu breeding potential of such reactors as well as on an important safety parameter, the void coefficient, which has to be negative. It is well known that fast reactors have a better neutron economy and are better suited than thermal reactors to breed fissile material from neutron capture in fertile material. Such fast reactors (e.g. sodium-cooled reactors) usually rely on technologies that are very different from those of existing water-cooled reactors and are probably more expensive. This report investigates another possibility to obtain a fast neutron reactor while still relying mostly on a PWR technology by: (1) Tightening the lattice pitch to reduce the water-to-fuel volume ratio compared to that of a standard PWR. Water-to-fuel volume ratios of between 0.45 and 1 have been considered in this study while a value of about 2 is typical of standard PWRs, (2) Using D2O instead of H2O as a coolant. Indeed, because of its different neutron physics properties, the use of D2O hardens the neutron spectrum to an extent impossible with H2O when used in a tight-pitch lattice. The neutron spectra thus obtained are not as fast as those in sodium-cooled reactor but they can still be characterized as fast compared to that of standard PWR neutron spectra. In the phase space investigated in this study we did not find any configurations that would have, at the same time, a positive Pu mass balance (more Pu at the end than at the beginning of the irradiation) and a negative void coefficient. At this stage, the use of radial blankets has only been briefly addressed whereas the impact of axial blankets has been well defined. For example, with a D2O-to-fuel volume ratio of 0.45 and a core driver height of about 60 cm, the fissile Pu mass balance between the fresh fuel and the irradiated fuel (50 GWd/t) would be about -7.5% (i.e. there are 7.5% fewer fissile Pu

  11. Preliminary seal design evaluation for the Waste Isolation Pilot Plant

    SciTech Connect

    Stormont, J C

    1988-03-01

    This report presents a preliminary evaluation of design concepts for the eventual sealing of the shafts, drifts, and boreholes at the Waste Isolation Pilot Plant Facility. The purpose of the seal systems is to limit the flow of water into, through, and out of the repository. The principal design strategy involves the consolidation of crushed or granular salt in response to the closure of the excavations in salt. Other candidate seal materials are bentonite, cementitious mixtures, and possibly asphalt. Results from in situ experiments and modeling studies, as well as laboratory materials testing and related industrial experience, are used to develop seal designs for shafts, waste storage panel entryways, non-waste containing drifts, and boreholes. Key elements of the ongoing experimental program are identified. 112 refs., 25 figs., 1 tab.

  12. Spectral response of the Viking lander camera: Preliminary evaluation

    NASA Technical Reports Server (NTRS)

    Kelly, W. L., IV; Huck, F. O.; Arvidson, R. E.

    1975-01-01

    One of the objectives of the Viking lander imaging investigation is to obtain color and near-infrared multispectral panoramas of the Martian surface using six spectral channels in the 0.4 to 1.1 microns wavelength range. This data can be compared with data obtained by imaging a reference test chart to construct approximate spectral reflectance curves that can then be matched to laboratory standards to aid in identifying surface materials. Some channels exhibit appreciable out-of-band spectral responses, making data reduction and interpretation difficult. A preliminary evaluation of predicted multispectral data for eight geological materials reveals that fairly good reflectance estimates can be made for those materials which have monotonically increasing or decreasing reflectances. Reflectance estimates for materials with more complex reflectances often do not reveal important spectral features and sometimes provide misleading results.

  13. A Serious Games Platform for Cognitive Rehabilitation with Preliminary Evaluation.

    PubMed

    Rego, Paula Alexandra; Rocha, Rui; Faria, Brígida Mónica; Reis, Luís Paulo; Moreira, Pedro Miguel

    2017-01-01

    In recent years Serious Games have evolved substantially, solving problems in diverse areas. In particular, in Cognitive Rehabilitation, Serious Games assume a relevant role. Traditional cognitive therapies are often considered repetitive and discouraging for patients and Serious Games can be used to create more dynamic rehabilitation processes, holding patients' attention throughout the process and motivating them during their road to recovery. This paper reviews Serious Games and user interfaces in rehabilitation area and details a Serious Games platform for Cognitive Rehabilitation that includes a set of features such as: natural and multimodal user interfaces and social features (competition, collaboration, and handicapping) which can contribute to augment the motivation of patients during the rehabilitation process. The web platform was tested with healthy subjects. Results of this preliminary evaluation show the motivation and the interest of the participants by playing the games.

  14. Measurement of leakage neutron spectra from graphite cylinders irradiated with D-T neutrons for validation of evaluated nuclear data.

    PubMed

    Luo, F; Han, R; Chen, Z; Nie, Y; Shi, F; Zhang, S; Lin, W; Ren, P; Tian, G; Sun, Q; Gou, B; Ruan, X; Ren, J; Ye, M

    2016-10-01

    A benchmark experiment for validation of graphite data evaluated from nuclear data libraries was conducted for 14MeV neutrons irradiated on graphite cylinder samples. The experiments were performed using the benchmark experimental facility at the China Institute of Atomic Energy (CIAE). The leakage neutron spectra from the surface of graphite (Φ13cm×20cm) at 60° and 120° and graphite (Φ13cm×2cm) at 60° were measured by the time-of-flight (TOF) method. The obtained results were compared with the measurements made by the Monte Carlo neutron transport code MCNP-4C with the ENDF/B-VII.1, CENDL-3.1 and JENDL-4.0 libraries. The results obtained from a 20cm-thick sample revealed that the calculation results with CENDL-3.1 and JENDL-4.0 libraries showed good agreements with the experiments conducted in the whole energy region. However, a large discrepancy of approximately 40% was observed below the 3MeV energy region with the ENDF/B-VII.1 library. For the 2cm-thick sample, the calculated results obtained from the abovementioned three libraries could not reproduce the experimental data in the energy range of 5-7MeV. The graphite data in CENDL-3.1 were verified for the first time and were proved to be reliable.

  15. Sonographic evaluation of pediatric localized scleroderma: preliminary disease assessment measures

    PubMed Central

    2010-01-01

    Background Our earlier work in the ultrasonograpy of localized scleroderma (LS) suggests that altered levels of echogenicity and vascularity can be associated with disease activity. Utrasound is clinically benign and readily available, but can be limited by operator dependence. We present our efforts to standardize image acquisition and interpretation of pediatric LS to better evaluate the correlation between specific sonographic findings and disease activity. Methods Several meetings have been held among our multi-center group (LOCUS) to work towards standardizing sonographic technique and image interpretation. Demonstration and experience in image acquisition were conducted at workshop meetings. Following meetings in 2007, an ultrasound measure was developed to standardize evaluation of differences in echogenicity and vascularity. Based upon our initial observations, we have labeled this an ultrasound disease activity measure. This preliminary measure was subsequently evaluated on over 180 scans of pediatric LS lesions. This review suggested that scoring levels should be expanded to better capture the range of observed differences. The revised levels and their definitions were formulated at a February 2009 workshop meeting. We have also developed assessments for scoring changes in tissue thickness and lesion size to better determine if these parameters aid evaluation of disease state. Results We have standardized our protocol for acquiring ultrasound images of pediatric LS lesions. A wide range of sonographic differences has been seen in the dermis, hypodermis, and deep tissue layers of active lesions. Preliminary ultrasound assessments have been generated. The disease activity measure scores for altered levels of echogenicity and vascularity in the lesion, and other assessments score for differences in lesion tissue layer thickness and changes in lesion size. Conclusions We describe the range of sonographic differences found in pediatric LS, and present our

  16. Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

    SciTech Connect

    Maheras, Steven J.; Best, Ralph E.; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.; McConnell, Paul E.; Massaro, Lawrence M.; Jensen, Philip J.

    2015-09-30

    A preliminary evaluation of removing spent nuclear fuel (SNF) from 13 shutdown nuclear power reactor sites was conducted. At these shutdown sites the nuclear power reactors have been permanently shut down and the sites have been decommissioned or are undergoing decommissioning. The shutdown sites were Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, San Onofre, and Vermont Yankee. The evaluation was divided into four components: (1) characterization of the SNF and greater-than-Class C low-level radioactive waste (GTCC waste) inventory, (2) a description of the on-site infrastructure and conditions relevant to transportation of SNF and GTCC waste, (3) an evaluation of the near-site transportation infrastructure and experience relevant to shipping transportation casks containing SNF and GTCC waste, including identification of gaps in information, and (4) an evaluation of the actions necessary to prepare for and remove SNF and GTCC waste. Every site was found to have at least one off-site transportation mode option for removing its SNF and GTCC waste; some have multiple options. Experience removing large components during reactor decommissioning provided an important source of information used to identify the transportation mode options for the sites. Especially important in conducting the evaluation were site visits, through which information was obtained that would not have been available otherwise. Extensive photographs taken during the site visits proved to be particularly useful in documenting the current conditions at or near the sites. It is expected that additional site visits will be conducted to add to the information presented in the evaluation.

  17. Evaluation of a PIN Photodiode Detector in Neutron-Gamma Fields

    NASA Astrophysics Data System (ADS)

    Cárdenas, José Patricio N.; Campos, Letícia L.; Filho, Tufic Madi

    2011-08-01

    Semiconductor detectors are suitable for applications in radiation dosimetry in nuclear research reactors and for radiation protection purposes. The performance of these detectors depends on the quality of their semiconductor. The aim of this work was to evaluate a commercial PIN Photodiode in the neutron-gamma fields of the IEA-R1 nuclear research reactor and from an AmBe neutron source. This semiconductor was studied as a neutron detector using some types of converters to determine a dose-to-counts conversion factor to dose equivalent. The results have shown that this component may be implemented for assessing the neutron spectra in some radiation fields and in dose equivalent in radiation protection routines.

  18. Measurement/Evaluation Techniques and Nuclear Data Associated with Fission of 239Pu by Fission Spectrum Neutrons

    SciTech Connect

    Baisden, P; Bauge, E; Ferguson, J; Gilliam, D; Granier, T; Jeanloz, R; McMillan, C; Robertson, D; Thompson, P; Verdon, C; Wilkerson, C; Young, P

    2010-03-16

    This Panel was chartered to review and assess new evaluations of work on fission product data, as well as the evaluation process used by the two U.S. nuclear weapons physics laboratories. The work focuses on fission product yields resulting from fission spectrum neutrons incident on plutonium, and includes data from measurements that had not been previously published as well as new or revised fission product cumulative yield data, and related quantities such as Q values and R values. This report documents the Panel's assessment of the work presented by Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). Based on the work presented we have seven key observations: (1) Experiments conducted in the 1970s at LANL, some of which were performed in association with a larger, NIST-led, program, have recently been documented. A preliminary assessment of this work, which will be referred to in this document as ILRR-LANL, shows it to be technically sound. (2) LLNL has done a thorough, unbiased review and evaluation of the available literature and is in the process of incorporating the previously unavailable LANL data into its evaluation of key fission product yields. The results of the LLNL effort, which includes a preliminary evaluation of the ILRR-LANL data, have been documented. (3) LANL has also conducted an evaluation of fission product yields for fission spectrum neutrons on plutonium including a meta-analysis of benchmark data as part of a planned upgrade to the ENDF/B compilation. We found that the approach of using meta-analysis provides valuable additional insight for evaluating the sparse data sets involved in this assessment. (4) Both laboratories have provided convincing evidence for energy dependence in the fission product yield of {sup 147}Nd produced from the bombardment of {sup 239}Pu with fission spectrum neutrons over an incident neutron energy range of 0.2 to 1.9 MeV. (5) Consistent, complete, and explicit treatment of

  19. Preliminary safety evaluation of the advanced burner test reactor.

    SciTech Connect

    Dunn, F. E.; Fanning, T. H.; Cahalan, J. E.; Nuclear Engineering Division

    2006-09-15

    Results of a preliminary safety evaluation of the Advanced Burner Test Reactor (ABTR) pre-conceptual design are reported. The ABTR safety design approach is described. Traditional defense-in-depth design features are supplemented with passive safety performance characteristics that include natural circulation emergency decay heat removal and reactor power reduction by inherent reactivity feedbacks in accidents. ABTR safety performance in design-basis and beyond-design-basis accident sequences is estimated based on analyses. Modeling assumptions and input data for safety analyses are presented. Analysis results for simulation of simultaneous loss of coolant pumping power and normal heat rejection are presented and discussed, both for the case with reactor scram and the case without reactor scram. The analysis results indicate that the ABTR pre-conceptual design is capable of undergoing bounding design-basis and beyond-design-basis accidents without fuel cladding failures. The first line of defense for protection of the public against release of radioactivity in accidents remains intact with significant margin. A comparison and evaluation of general safety design criteria for the ABTR conceptual design phase are presented in an appendix. A second appendix presents SASSYS-1 computer code capabilities and modeling enhancements implemented for ABTR analyses.

  20. Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

    SciTech Connect

    Maheras, Steven J.; Best, Ralph E.; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.; McConnell, Paul E.

    2013-09-30

    This report fulfills the M2 milestone M2FT-13PN0912022, “Stranded Sites De-Inventorying Report.” In January 2013, the U.S. Department of Energy (DOE) issued the Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste (DOE 2013). Among the elements contained in this strategy is an initial focus on accepting used nuclear fuel from shutdown reactor sites. This focus is consistent with the recommendations of the Blue Ribbon Commission on America’s Nuclear Future, which identified removal of stranded used nuclear fuel at shutdown sites as a priority so that these sites may be completely decommissioned and put to other beneficial uses (BRC 2012). Shutdown sites are defined as those commercial nuclear power reactor sites where the nuclear power reactors have been shut down and the site has been decommissioned or is undergoing decommissioning. In this report, a preliminary evaluation of removing used nuclear fuel from 12 shutdown sites was conducted. The shutdown sites were Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, and San Onofre. These sites have no other operating nuclear power reactors at their sites and have also notified the U.S. Nuclear Regulatory Commission that their reactors have permanently ceased power operations and that nuclear fuel has been permanently removed from their reactor vessels. Shutdown reactors at sites having other operating reactors are not included in this evaluation.

  1. Preliminary Field Evaluation of Mercury Control Using Combustion Modifications

    SciTech Connect

    V. Lissianski; P. Maly; T. Marquez

    2005-01-22

    In this project EER conducted a preliminary field evaluation of the integrated approach for mercury (Hg) and NO{sub x} control. The approach enhanced the 'naturally occurring' Hg capture by fly ash through combustion optimization, increasing carbon in ash content, and lowering ESP temperature. The evaluation took place in Green Station Units 1 and 2 located near Henderson, Kentucky and operated by Western Kentucky Energy. Units 1 and 2 are equipped with cold-side ESPs and wet scrubbers. Green Station Units 1 and 2 typically fire two types of fuel: a bituminous coal and a blend of bituminous coals based on availability. Testing of Hg emissions in Unit 2 without reburning system in operation and at minimum OFA demonstrated that efficiencies of Hg reduction downstream of the ESP were 30-40%. Testing also demonstrated that OFA system operation at 22% air resulted in 10% incremental increase in Hg removal efficiency at the ESP outlet. About 80% of Hg in flue gas at ESP outlet was present in the oxidized form. Testing of Hg emissions under reburning conditions showed that Hg emissions decreased with LOI increase and ESP temperature decrease. Testing demonstrated that maximum Hg reduction downstream of ESP was 40-45% at ESP temperatures higher than 300 F and 60-80% at ESP temperatures lower than 300 F. The program objective to demonstrate 80% Hg removal at the ESP outlet has been met.

  2. PRELIMINARY FIELD EVALUATION OF MERCURY CONTROL USING COMBUSTION MODIFICATIONS

    SciTech Connect

    Vitali Lissianski; Antonio Marquez

    2004-02-19

    In this project General Electric Energy and Environmental Research Corporation conducts a preliminary field evaluation of a novel technology, referred to as Hg/NO{sub x}, that can reduce emissions of both mercury (Hg) and oxides of nitrogen (NO{sub x}) from coal-fired power plants. The evaluation takes place in Green Station Unit 2 operated by Western Kentucky Energy. Reduction of Hg and NO{sub x} emissions in Unit 2 is achieved using coal reburning. Activities during first project year (January 23, 2003--January 22, 2004) included measurements of baseline Hg emissions in Unit 2 and pilot-scale testing. Baseline testing of Hg emissions in Green Unit 2 has been completed. Two fuels were tested with OFA system operating at minimum air flow. Mercury emissions were measured at ESP inlet and outlet, and at the stack using Ontario Hydro revised method. Testing demonstrated that baseline Hg reductions at ESP outlet and stack were 30-45% and 70-80%, respectively. Pilot-scale testing demonstrated good agreement with baseline measurements in Unit 2. Testing showed that fuel composition had an effect on the efficiency of Hg absorption on fly ash. Maximum achieved Hg removal in reburning was close to 90%. Maximum achieved Hg reduction at air staging conditions was 60%. Testing also demonstrated that lowering ESP temperature improved efficiency of Hg removal.

  3. Data evaluation methods and improvements to the neutron-capture γ-ray spectrum

    NASA Astrophysics Data System (ADS)

    Hurst, A. M.; Firestone, R. B.; Summers, N. C.; Sleaford, B. W.; Revay, Zs.; Krtička, M.; Belgya, T.; Basunia, M. S.; Capote, R.; Choi, H.; Dashdorj, D.; Escher, J. E.; Nichols, A.; Szentmiklósi, L.

    2011-06-01

    Improved neutron-capture γ-ray spectra, not only of interest to the nuclear structure and reactions communities, are needed in a variety of applied and non-proliferation programs. This requires an evaluation of the existing experimental capture-γ data. Elemental neutron-capture data taken from direct measurements at the Budapest Reactor have been used to collate the Evaluated Gamma-ray Activation File, a database of capture γ-ray cross sections. These cross sections are then compared to Monte Carlo simulations of γ-ray emission following the thermal neutron-capture process using the statistical-decay code DICEBOX. The aim of this procedure is to obtain the total radiative neutron-capture cross section and confidently increase the number of levels and γ rays that can be assigned to a given isotope in the neutron data libraries. To achieve these goals and provide as complete information as possible in the neutron data libraries, it is also necessary to remain current with recent advances in nuclear structure physics and ensure that the latest data in the Evaluated Nuclear Structure Data File has been taken into consideration. This way an optimal level scheme can be derived by comparison with simulations and available experimental data. New information derived from this study can then be used to improve the nuclear structure and reactions databases with more-complete level schemes, and indeed, provide reliable and accurate input to a variety of applications which require this information. Recent results from neutron capture on the stable tungsten isotopes 182,183,184,186W are presented to illustrate the evaluation process.

  4. Fast Neutron Dose Evaluation Using CR39 by Coincidence Counting Process

    SciTech Connect

    Vilela, Eudice; Freitas, F. F. de; Brandao, J. O. C.; Santos, J. A. L.

    2008-08-07

    The solid state nuclear tracks detection (SSNTD) technique is widely used in the area of radiation dosimetry. Different materials can be used applying this technique as glass and the most used in the dosimetry field that are the polycarbonates, CR39 and Makrofol-DE. Both are very rich in hydrogenous, that enables the SSNTD to detect fast neutrons through recoils of protons in the own detector material, without need of converters. The low reproducibility of its backgroundhas often been the major drawback in the assessment of low fluences of fast neutrons with SSNTDs. This problem can be effectively solved by counting coincidence of tracks in two detectors foils irradiated in close contact. After processing and counting only tracks produced by the same recoil nuclei on the surfaces of both detectors are considered as a track. This procedure enables the reduction of the background counts in the response of the detectors. In this work a preliminary study on the application of the coincidence technique for neutron dosimetry is presented. The CR39 material was investigated aiming to achieve the personal dose equivalent for fast neutrons. Using this method of analysis a significant reduction on the lower detectable dose was observed resulting even one order of magnitude smaller value. Reading, however, needs to be automated due to the large areas necessary to achieve a satisfactory number of tracks for statistical significance of results.

  5. Comparison of different MC techniques to evaluate BNCT dose profiles in phantom exposed tovarious neutron fields.

    PubMed

    Durisi, E; Koivunoro, H; Visca, L; Borla, O; Zanini, A

    2010-03-01

    The absorbed dose in BNCT (boron neutron capture therapy) consists of several radiation components with different physical properties and biological effectiveness. In order to assess the clinical efficacy of the beams, determining the dose profiles in tissues, Monte Carlo (MC) simulations are used. This paper presents a comparison between dose profiles calculated in different phantoms using two techniques: MC radiation transport code, MCNP-4C2 and BNCT MC treatment planning program, SERA (simulation environment for radiotherapy application). In this study MCNP is used as a reference tool. A preliminary test of SERA is performed using six monodirectional and monoenergetic beams directed onto a simple water phantom. In order to deeply investigate the effect of the different cross-section libraries and of the dose calculation methodology, monoenergetic and monodirectional beams directed toward a standard Snyder phantom are simulated. Neutron attenuation curves and dose profiles are calculated with both codes and the results are compared.

  6. Preliminary evaluation of a lake whitefish (Coregonus clupeaformis) bioenergetics model

    USGS Publications Warehouse

    Madenjian, Charles P.; Pothoven, Steven A.; Schneeberger, Philip J.; O'Connor, Daniel V.; Brandt, Stephen B.

    2005-01-01

    We conducted a preliminary evaluation of a lake whitefish (Coregonus clupeaformis) bioenergetics model by applying the model to size-at-age data for lake whitefish from northern Lake Michigan. We then compared estimates of gross growth efficiency (GGE) from our bioenergetis model with previously published estimates of GGE for bloater (C. hoyi) in Lake Michigan and for lake whitefish in Quebec. According to our model, the GGE of Lake Michigan lake whitefish decreased from 0.075 to 0.02 as age increased from 2 to 5 years. In contrast, the GGE of lake whitefish in Quebec inland waters decreased from 0.12 to 0.05 for the same ages. When our swimming-speed submodel was replaced with a submodel that had been used for lake trout (Salvelinus namaycush) in Lake Michigan and an observed predator energy density for Lake Michigan lake whitefish was employed, our model predicted that the GGE of Lake Michigan lake whitefish decreased from 0.12 to 0.04 as age increased from 2 to 5 years.

  7. Preliminary systems engineering evaluations for the National Ecological Observatory Network.

    SciTech Connect

    Robertson, Perry J.; Kottenstette, Richard Joseph; Crouch, Shannon M.; Brocato, Robert Wesley; Zak, Bernard Daniel; Osborn, Thor D.; Ivey, Mark D.; Gass, Karl Leslie; Heller, Edwin J.; Dishman, James Larry; Schubert, William Kent; Zirzow, Jeffrey A.

    2008-11-01

    The National Ecological Observatory Network (NEON) is an ambitious National Science Foundation sponsored project intended to accumulate and disseminate ecologically informative sensor data from sites among 20 distinct biomes found within the United States and Puerto Rico over a period of at least 30 years. These data are expected to provide valuable insights into the ecological impacts of climate change, land-use change, and invasive species in these various biomes, and thereby provide a scientific foundation for the decisions of future national, regional, and local policy makers. NEON's objectives are of substantial national and international importance, yet they must be achieved with limited resources. Sandia National Laboratories was therefore contracted to examine four areas of significant systems engineering concern; specifically, alternatives to commercial electrical utility power for remote operations, approaches to data acquisition and local data handling, protocols for secure long-distance data transmission, and processes and procedures for the introduction of new instruments and continuous improvement of the sensor network. The results of these preliminary systems engineering evaluations are presented, with a series of recommendations intended to optimize the efficiency and probability of long-term success for the NEON enterprise.

  8. Preliminary Evaluation of Polyarylate Dielectric Films for Cryogenic Applications

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Hammoud, Ahmad; Fialla, Peter

    2002-01-01

    Polymeric materials are used extensively on spacecraft and satellites in electrical power and distribution systems, as thermal blankets and optical surface coatings, as well as mechanical support structures. The reliability of these systems when exposed to the harsh environment of space is very critical to the success of the mission and the safety of the crew in manned-flight ventures. In this work, polyarylate films were evaluated for potential use as capacitor dielectrics and wiring insulation for cryogenic applications. Two grades of the film were characterized in terms of their electrical and mechanical properties before and after exposure to liquid nitrogen (-196 C). The electrical characterization consisted of capacitance and dielectric loss measure Cents in the frequency range of 50 Hz to 100 kHz, and volume and surface resistivities. The mechanical measurements performed included changes in tensile (Young's modulus, elongation-at-break, and tensile strength) and structural properties (dimensional change, weight, and surface morphology). The preliminary results, which indicate good stability of the polymer after exposure to liquid nitrogen, are presented and discussed.

  9. Preliminary Evaluation of Thematic Mapper Image Data Quality

    NASA Technical Reports Server (NTRS)

    Macdonald, R. B.; Hall, F. G.; Pitts, D. E.; Bizzell, R. M.; Yao, S.; Sorensen, C.; Reyna, E.; Carnes, J. G.

    1984-01-01

    Thematic Mapper (TM) data from Mississippi County, Arkansas, and Webster County, Iowa, were examined for the purpose of evaluating the image data quality of the TM which was launched on board the LANDSAT-4 spacecraft. Preliminary clustering and principal component analysis indicates that the middle infrared and thermal infrared data of TM appear to add significant information over that of the near IR and visible bands of the multispectral scanner data. Moreover, the higher spatial resolution of TM appears to provide better definition of the edges and the within variability of agricultural fields. The geometric performance of TM data, without ground control correction, was found to exceed expectations. The modulation transfer function for the 1.65 m band was found to agree with prelaunch specifications when the effects of the GSFC cubic convolution and the atmosphere were removed. The band to band registration for the bands within the noncooled focal plane was found to be better than specified. However, the middle infrared and thermal infrared, which are on a separate cooled focal plane were found to be misregistered and were significantly worse than prelaunch specifications.

  10. Preliminary Design and Evaluation of Portable Electronic Flight Progress Strips

    NASA Technical Reports Server (NTRS)

    Doble, Nathan A.; Hansman, R. John

    2002-01-01

    There has been growing interest in using electronic alternatives to the paper Flight Progress Strip (FPS) for air traffic control. However, most research has been centered on radar-based control environments, and has not considered the unique operational needs of the airport air traffic control tower. Based on an analysis of the human factors issues for control tower Decision Support Tool (DST) interfaces, a requirement has been identified for an interaction mechanism which replicates the advantages of the paper FPS (e.g., head-up operation, portability) but also enables input and output with DSTs. An approach has been developed which uses a Portable Electronic FPS that has attributes of both a paper strip and an electronic strip. The prototype flight strip system uses Personal Digital Assistants (PDAs) to replace individual paper strips in addition to a central management interface which is displayed on a desktop computer. Each PDA is connected to the management interface via a wireless local area network. The Portable Electronic FPSs replicate the core functionality of paper flight strips and have additional features which provide a heads-up interface to a DST. A departure DST is used as a motivating example. The central management interface is used for aircraft scheduling and sequencing and provides an overview of airport departure operations. This paper will present the design of the Portable Electronic FPS system as well as preliminary evaluation results.

  11. Preventative Vaccines for Zika Virus Outbreak: Preliminary Evaluation.

    PubMed

    Kim, Eun; Erdos, Geza; Huang, Shaohua; Kenniston, Thomas; Falo, Louis D; Gambotto, Andrea

    2016-11-01

    Since it emerged in Brazil in May 2015, the mosquito-borne Zika virus (ZIKV) has raised global concern due to its association with a significant rise in the number of infants born with microcephaly and neurological disorders such as Guillain-Barré syndrome. We developed prototype subunit and adenoviral-based Zika vaccines encoding the extracellular portion of the ZIKV envelope gene (E) fused to the T4 fibritin foldon trimerization domain (Efl). The subunit vaccine was delivered intradermally through carboxymethyl cellulose microneedle array (MNA). The immunogenicity of these two vaccines, named Ad5.ZIKV-Efl and ZIKV-rEfl, was tested in C57BL/6 mice. Prime/boost immunization regimen was associated with induction of a ZIKV-specific antibody response, which provided neutralizing immunity. Moreover, protection was evaluated in seven-day-old pups after virulent ZIKV intraperitoneal challenge. Pups born to mice immunized with Ad5.ZIKV-Efl were all protected against lethal challenge infection without weight loss or neurological signs, while pups born to dams immunized with MNA-ZIKV-rEfl were partially protected (50%). No protection was seen in pups born to phosphate buffered saline-immunized mice. This study illustrates the preliminary efficacy of the E ZIKV antigen vaccination in controlling ZIKV infectivity, providing a promising candidate vaccine and antigen format for the prevention of Zika virus disease.

  12. Ultrasonic Evaluation of Deeply Located Trabecular Bones - Preliminary Results

    NASA Astrophysics Data System (ADS)

    Cieślik, Lucyna; Litniewski, Jerzy

    The analysis of ultrasonic signals scattered by soft tissues have been successfully applied for their characterization. Similarly, the trabecular bone backscattered signal contains information about the properties of the bone structure. Therefore scattering-based ultrasonic technique potentially enables the assessment of microstructure characteristics of a bone. The femoral neck fracture often occurs in the course of osteoporosis and can lead to severe complications. Therefore assessment of femoral bone microstructure and condition is important and essential for the diagnosis and treatment monitoring. As far most of the trabecular bone investigations have been performed in vitro. The only in vivo measurements were carried out in transmission and mostly concerned estimation of the attenuation in heel bone. We have built the ultrasonic scanner that could be useful in acquiring the RF (Radio Frequency) echoes backscattered by the trabecular bone in vivo. Moreover, the bone scanner provides data not only from heel bone but from deeply located bones as well (e.g. femoral bone). It can be also used for easily accessible bones like heel bone or breastbone. In this case a gel-pad is applied to assure focusing of ultrasound in trabecular bone (approximately 10 mm beneath the cortical bone). This study presents preliminary results of the attenuating properties evaluation of trabecular bone from the ultrasonic echoes backscattered by heel bone and femoral neck.

  13. Preliminary physicochemical evaluation of Kushta tutia: A Unani Formulation

    PubMed Central

    Tariq, Mohd; Chaudhary, Shahid Shah; Imtiyaz, Shaikh; Rahman, Khaleequr; Zaman, Roohi

    2014-01-01

    Background: Kushta is an important solid dosage form of Unani system of medicine used to treat various ailments. Very small particle size of kushta is responsible for its rapid absorption in body leading to instant therapeutic actions. Kushta tutia (KT) is one such renowned formulation used by hakims for successful management of various disorders. However, there is lack of scientific work on KT. Objectives: The present study was performed to evaluate KT physicochemically by testifying it on classical tests along with modern scientific techniques. Materials and Methods: Tutia was first detoxified as per classical literature. It was triturated with water and dried, afterwards subjected to calcination in furnace rather than cow dung cakes due to isolation of material being heated and better temperature control. Finished product was evaluated for physicochemical characteristics including preliminary tests mentioned in classical literature. Results: Floating and finger test were positive. Curd test showed no discoloration after 48 h. These findings indicate correct preparation of KT according to classical literature. Bulk density (0.96 ± 0.00 g/ml); tapped density (1.53 ± 0.00 g/ml); Hausner ratio (0.62 ± 0.00), compressibility index (37.52 ± 0.19%); loss of weight on drying (0.08 ± 0.00%); pH of 1 and 10% (5.20 ± 0.00) and 5.62 ± 0.00, respectively); total ash, acid insoluble ash, and water soluble ash values 95.75 ± 0.09, 6.57 ± 0.02, and 45.02 ± 0.20%, respectively; and extractive values 0.85 ± 0.02% were reported in KT. Conclusion: Since this work has not been reported earlier, the results obtained could be considered as the standard for KT for future studies. PMID:25336845

  14. EVALUATION OF NEUTRON CROSS SECTIONS FOR A COMPLETE SET OF Nd ISOTOPES.

    SciTech Connect

    KIM,H.; HERMAN, M.; MUGHABGHAB, S.F.; OBLOZINSKY, P.; ROCHMAN, D.; LEE. Y.-O.

    2007-10-29

    Neutron cross sections for a complete set of Nd isotopes, {sup 142,143,144,145,146,147,148,150}Nd, were evaluated in the incident energy range from 10{sup -5} eV to 20 MeV. In the low energy region, including thermal and resolved resonances, our evaluations are based on the latest data published in the Atlas of Neutron Resonances. In the unresolved resonance region we performed additional evaluation by using the averages of the resolved resonances and adjusting them to the experimental data. In the fast neutron region, we used the nuclear reaction model code EMPIRE-2.19 validated against the experimental data. The results are compared to the existing nuclear data libraries, including ENDF/B-VI.8, JENDL-3.3 and JEFF-3.1, and to the available experimental data. The new evaluations are suitable for neutron transport calculations and they were adopted by the new evaluated nuclear data file of the United States, ENDF/B-VII.0, released in December 2006.

  15. Neutron scattering in Australia

    SciTech Connect

    Knott, R.B.

    1994-12-31

    Neutron scattering techniques have been part of the Australian scientific research community for the past three decades. The High Flux Australian Reactor (HIFAR) is a multi-use facility of modest performance that provides the only neutron source in the country suitable for neutron scattering. The limitations of HIFAR have been recognized and recently a Government initiated inquiry sought to evaluate the future needs of a neutron source. In essence, the inquiry suggested that a delay of several years would enable a number of key issues to be resolved, and therefore a more appropriate decision made. In the meantime, use of the present source is being optimized, and where necessary research is being undertaken at major overseas neutron facilities either on a formal or informal basis. Australia has, at present, a formal agreement with the Rutherford Appleton Laboratory (UK) for access to the spallation source ISIS. Various aspects of neutron scattering have been implemented on HIFAR, including investigations of the structure of biological relevant molecules. One aspect of these investigations will be presented. Preliminary results from a study of the interaction of the immunosuppressant drug, cyclosporin-A, with reconstituted membranes suggest that the hydrophobic drug interdigitated with lipid chains.

  16. Passive Safety Features Evaluation of KIPT Neutron Source Facility

    SciTech Connect

    Zhong, Zhaopeng; Gohar, Yousry

    2016-06-01

    Argonne National Laboratory (ANL) of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have cooperated on the development, design, and construction of a neutron source facility. The facility was constructed at Kharkov, Ukraine and its commissioning process is underway. It will be used to conduct basic and applied nuclear research, produce medical isotopes, and train young nuclear specialists. The facility has an electron accelerator-driven subcritical assembly. The electron beam power is 100 kW using 100 MeV electrons. Tungsten or natural uranium is the target material for generating neutrons driving the subcritical assembly. The subcritical assembly is composed of WWR-M2 - Russian fuel assemblies with U-235 enrichment of 19.7 wt%, surrounded by beryllium reflector assembles and graphite blocks. The subcritical assembly is seated in a water tank, which is a part of the primary cooling loop. During normal operation, the water coolant operates at room temperature and the total facility power is ~300 KW. The passive safety features of the facility are discussed in in this study. Monte Carlo computer code MCNPX was utilized in the analyses with ENDF/B-VII.0 nuclear data libraries. Negative reactivity temperature feedback was consistently observed, which is important for the facility safety performance. Due to the design of WWR-M2 fuel assemblies, slight water temperature increase and the corresponding water density decrease produce large reactivity drop, which offset the reactivity gain by mistakenly loading an additional fuel assembly. The increase of fuel temperature also causes sufficiently large reactivity decrease. This enhances the facility safety performance because fuel temperature increase provides prompt negative reactivity feedback. The reactivity variation due to an empty fuel position filled by water during the fuel loading process is examined. Also, the loading mistakes of removing beryllium reflector assemblies and

  17. Preliminary Airworthiness Evaluation of the Rutan Aircraft Factory (RAF) , Inc. LONG-EZ Airplane

    DTIC Science & Technology

    1983-06-01

    If) USMAEFA PROJECT NO,. 82-18 PRELIMINARY AIRWORTHINESS EVALUATION OF THE RUTAN AIRCRAFT FACTORY (RAF), INC. LONG-EZ AIRPLANE VERNON L. DIEIOWIN...REPORT & PEIOO COVERED PRELIMINARY AIRWORTHINESS EVALUATION 14 JAN - 1 APR 1983 OF THE RUTAN AIRCRAFT FACTORY (RAF), FINAL INC. LONG-HZ AIRPLANE 6... Airworthiness Evaluation of the Rutan Aircraft Factory, Inc. designed * airplane ~ 4Jnmy-hog---pi -40 at Edwards Calif,~gn4&. During the test program 34

  18. Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

    SciTech Connect

    Maheras, Steven J.; Best, Ralph E.; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.; McConnell, Paul E.; Massaro, Lawrence M.; Jensen, Philip J.

    2014-10-01

    This report presents a preliminary evaluation of removing used nuclear fuel (UNF) from 12 shutdown nuclear power plant sites. At these shutdown sites the nuclear power reactors have been permanently shut down and the sites have been decommissioned or are undergoing decommissioning. The shutdown sites are Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, and San Onofre. The evaluation was divided into four components: characterization of the UNF and greater-than-Class C low-level radioactive waste (GTCC waste) inventory; a description of the on-site infrastructure and conditions relevant to transportation of UNF and GTCC waste; an evaluation of the near-site transportation infrastructure and experience relevant to shipping transportation casks containing UNF and GTCC waste, including identification of gaps in information; and, an evaluation of the actions necessary to prepare for and remove UNF and GTCC waste. The primary sources for the inventory of UNF and GTCC waste are the U.S. Department of Energy (DOE) RW-859 used nuclear fuel inventory database, industry sources such as StoreFUEL and SpentFUEL, and government sources such as the U.S. Nuclear Regulatory Commission. The primary sources for information on the conditions of site and near-site transportation infrastructure and experience included observations and information collected during visits to the Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, and Zion sites; information provided by managers at the shutdown sites; Facility Interface Data Sheets compiled for DOE in 2005; Services Planning Documents prepared for DOE in 1993 and 1994; industry publications such as Radwaste Solutions; and Google Earth. State and Regional Group representatives, a Tribal representative, and a Federal Railroad Administration representative participated in six of the shutdown site

  19. New Neutron Cross-Section Measurements from ORELA and New Resonance Parameter Evaluations

    SciTech Connect

    Guber, Klaus H; Koehler, Paul; Wiarda, Dorothea; Harvey, John A; Valentine, Timothy E; Sayer, Royce O; Leal, Luiz C; Larson, Nancy M; Bigelow, Tim S

    2008-01-01

    A series of new measurements has been undertaken in response to deficiencies identified in nuclear data libraries of crucial importance to the Nuclear Criticality Safety Program. New data and evaluations, including covariances, are required for several materials found in mixtures with uranium. For this purpose we performed neutron capture and total cross-section measurements on natural potassium, {sup 41}K, and manganese.

  20. Preliminary evaluation of the hydrogeologic system in Owens Valley, California

    USGS Publications Warehouse

    Danskin, W.R.

    1988-01-01

    A preliminary, two-layer, steady-state, groundwater flow model was used to evaluate present data and hydrologic concepts of Owens Valley, California. Simulations of the groundwater system indicate that areas where water levels are most affected by changes in recharge and discharge are near toes of alluvial fans and along the edge of permeable volcanic deposits. Sensitivity analysis for each model parameter shows that steady state simulations are most sensitive to uncertainties in evapotranspiration rates. Tungsten Hills, Poverty Hills, and Alabama Hills were found to act as virtually impermeable barriers to groundwater flow. Accurate simulation of the groundwater system between Bishop and Lone Pine appears to be possible without simulating the groundwater system in Round Valley, near Owens Lake, or in aquifer materials more than 1,000 ft below land surface. Although vast amounts of geologic and hydrologic data have been collected for Owens Valley, many parts of the hydrogeologic system have not been defined with sufficient detail to answer present water management questions. Location and extent of geologic materials that impede the vertical movement of water are poorly documented. The likely range of aquifer characteristics, except vertical hydraulic conductivity, is well known, but spatial distribution of these characteristics is not well documented. A set of consistent water budgets is needed, including one for surface water, groundwater, and the entire valley. The largest component of previous water budgets (evapotranspiration) is largely unverified. More definitive estimates of local gains and losses for Owens River are needed. Although groundwater pumpage from each well is measured, the quantity of withdrawal from different zones of permeable material has not been defined. (USGS)

  1. An Evaluation of Monte Carlo Simulations of Neutron Multiplicity Measurements of Plutonium Metal

    SciTech Connect

    Mattingly, John; Miller, Eric; Solomon, Clell J. Jr.; Dennis, Ben; Meldrum, Amy; Clarke, Shaun; Pozzi, Sara

    2012-06-21

    In January 2009, Sandia National Laboratories conducted neutron multiplicity measurements of a polyethylene-reflected plutonium metal sphere. Over the past 3 years, those experiments have been collaboratively analyzed using Monte Carlo simulations conducted by University of Michigan (UM), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), and North Carolina State University (NCSU). Monte Carlo simulations of the experiments consistently overpredict the mean and variance of the measured neutron multiplicity distribution. This paper presents a sensitivity study conducted to evaluate the potential sources of the observed errors. MCNPX-PoliMi simulations of plutonium neutron multiplicity measurements exhibited systematic over-prediction of the neutron multiplicity distribution. The over-prediction tended to increase with increasing multiplication. MCNPX-PoliMi had previously been validated against only very low multiplication benchmarks. We conducted sensitivity studies to try to identify the cause(s) of the simulation errors; we eliminated the potential causes we identified, except for Pu-239 {bar {nu}}. A very small change (-1.1%) in the Pu-239 {bar {nu}} dramatically improved the accuracy of the MCNPX-PoliMi simulation for all 6 measurements. This observation is consistent with the trend observed in the bias exhibited by the MCNPX-PoliMi simulations: a very small error in {bar {nu}} is 'magnified' by increasing multiplication. We applied a scalar adjustment to Pu-239 {bar {nu}} (independent of neutron energy); an adjustment that depends on energy is probably more appropriate.

  2. Event-by-event evaluation of the prompt fission neutron spectrum from 239Pu(n,f)

    SciTech Connect

    Vogt, R; Randrup, J; Brown, D A; Descalle, M A; Ormand, W E

    2011-11-28

    We have developed an improved evaluation method for the spectrum of neutrons emitted in fission of {sup 239}Pu induced by incident neutrons with energies up to 20 MeV. The covariance data, including incident energy correlations introduced by the evaluation method, were used to fix the input parameters in our event-by-event model of fission, FREYA, by applying formal statistical methods. Formal estimates of uncertainties in the evaluation were developed by randomly sampling model inputs and calculating likelihood functions based on agreement with the evaluated . Our approach is able to employ a greater variety of fission measurements than the relatively coarse spectral data alone. It also allows the study of numerous fission observables for more accurate model validation. The combination of an event-by-event Monte Carlo fission model with a statistical-likelihood analysis is thus a powerful tool for evaluation of fission-neutron data. Our empirical model FREYA follows the complete fission event from birth of the excited fragments through their decay via neutron emission until the fragment excitation energy is below the neutron separation energy when neutron emission can no longer occur. The most recent version of FREYA incorporates pre-equilibrium neutron emission, the emission of the first neutron before equilibrium is reached in the compound nucleus, and multi-chance fission, neutron evaporation prior to fission when the incident neutron energy is above the neutron separation energy. Energy, momentum, charge and mass number are conserved throughout the fission process. The best available values of fragment masses and total kinetic energies are used as inputs to FREYA. We fit three parameters that are not well under control from previous measurements: the shift in the total fragment kinetic energy; the energy scale of the asymptotic level density parameter, controlling the fragment 'temperature' for neutron evaporation; and the relative excitation of the

  3. PRELIMINARY RESULTS: EVALUATIONS OF THE ALTERNATIVE ASBESTOS CONTROL METHOD FOR BUILDING DEMOLITION

    EPA Science Inventory

    This presentation describes the preliminary results of the evaluations of the alternative asbestos control method for demolishing buildings containing asbestos, and are covered under the regulatory requirements of the Asbestos NESHAP. This abstract and presentation are based, at ...

  4. Notification: Preliminary Research to Evaluate Hazardous Waste Passing Through Publicly Owned Treatment Works

    EPA Pesticide Factsheets

    March 13, 2013. The EPA's OIG plans to start preliminary research to evaluate the effectiveness of the EPA’s programs in preventing and addressing contamination of surface water from hazardous wastes passing through publicly owned treatment works.

  5. Preliminary evaluation of diabatic heating distribution from FGGE level 3b analysis data

    NASA Technical Reports Server (NTRS)

    Kasahara, A.; Mizzi, A. P.

    1985-01-01

    A method is presented for calculating the global distribution of diabatic heating rate. Preliminary results of global heating rate evaluated from the European center for Medium Range Weather Forecasts Level IIIb analysis data is also presented.

  6. Evaluation of silicon neutron resonance parameters in the thermal to 1800 keV energy range.

    PubMed

    Derrien, H; Leal, L C; Guber, K H; Larson, N M

    2005-01-01

    Because silicon is a major constituent of concrete and soil, neutron and gamma ray information on silicon is important for reactor shielding and criticality safety calculations. Therefore, much effort was put into the ENDF/B-VI evaluation for the three stable isotopes of silicon. The neutron capture cross section of natural silicon was recently measured at the Oak Ridge Electron Linear Accelerator (ORELA) in the energy range 1-700 keV. Using the ENDF/B-VI evaluation for initial values, a new evaluation of the resonance parameters was performed by adding the results of the ORELA capture measurements to the experimental database. The computer code SAMMY was used for the analysis of the experimental data; the new version of SAMMY allows accurate calculations of the self-shielding and multiple scattering effects in the capture measurements. The accuracy of the radiative capture widths of the resonances was improved by this analysis. Accurate values of the s-, p- and d-wave neutron strength functions were also obtained. Although the resonance capture component of the present evaluation is 2-3 times smaller than that in ENDF/B-VI, the total capture cross section is much larger, at least for energies >250 keV, because the direct capture component contributes values of the same order of magnitude as the resonance component. The direct component was not taken into account in the ENDF/B-VI evaluation and was calculated for the first time in the present evaluation.

  7. Neutronics and Fuel Performance Evaluation of Accident Tolerant Fuel under Normal Operation Conditions

    SciTech Connect

    Xu Wu; Piyush Sabharwall; Jason Hales

    2014-07-01

    This report details the analysis of neutronics and fuel performance analysis for enhanced accident tolerance fuel, with Monte Carlo reactor physics code Serpent and INL’s fuel performance code BISON, respectively. The purpose is to evaluate two of the most promising candidate materials, FeCrAl and Silicon Carbide (SiC), as the fuel cladding under normal operating conditions. Substantial neutron penalty is identified when FeCrAl is used as monolithic cladding for current oxide fuel. From the reactor physics standpoint, application of the FeCrAl alloy as coating layer on surface of zircaloy cladding is possible without increasing fuel enrichment. Meanwhile, SiC brings extra reactivity and the neutron penalty is of no concern. Application of either FeCrAl or SiC could be favorable from the fuel performance standpoint. Detailed comparison between monolithic cladding and hybrid cladding (cladding + coating) is discussed. Hybrid cladding is more practical based on the economics evaluation during the transition from current UO2/zircaloy to Accident Tolerant Fuel (ATF) system. However, a few issues remain to be resolved, such as the creep behavior of FeCrAl, coating spallation, inter diffusion with zirconium, etc. For SiC, its high thermal conductivity, excellent creep resistance, low thermal neutron absorption cross section, irradiation stability (minimal swelling) make it an excellent candidate materials for future nuclear fuel/cladding system.

  8. Evaluation of reconstruction errors and identification of artefacts for JET gamma and neutron tomography

    SciTech Connect

    Craciunescu, Teddy Tiseanu, Ion; Zoita, Vasile; Murari, Andrea; Kiptily, Vasily; Sharapov, Sergei; Lupelli, Ivan; Fernandes, Ana; Collaboration: EUROfusion Consortium, JET, Culham Science Centre, Abingdon OX14 3DB

    2016-01-15

    The Joint European Torus (JET) neutron profile monitor ensures 2D coverage of the gamma and neutron emissive region that enables tomographic reconstruction. Due to the availability of only two projection angles and to the coarse sampling, tomographic inversion is a limited data set problem. Several techniques have been developed for tomographic reconstruction of the 2-D gamma and neutron emissivity on JET, but the problem of evaluating the errors associated with the reconstructed emissivity profile is still open. The reconstruction technique based on the maximum likelihood principle, that proved already to be a powerful tool for JET tomography, has been used to develop a method for the numerical evaluation of the statistical properties of the uncertainties in gamma and neutron emissivity reconstructions. The image covariance calculation takes into account the additional techniques introduced in the reconstruction process for tackling with the limited data set (projection resampling, smoothness regularization depending on magnetic field). The method has been validated by numerically simulations and applied to JET data. Different sources of artefacts that may significantly influence the quality of reconstructions and the accuracy of variance calculation have been identified.

  9. Evaluation of reconstruction errors and identification of artefacts for JET gamma and neutron tomography.

    PubMed

    Craciunescu, Teddy; Murari, Andrea; Kiptily, Vasily; Lupelli, Ivan; Fernandes, Ana; Sharapov, Sergei; Tiseanu, Ion; Zoita, Vasile

    2016-01-01

    The Joint European Torus (JET) neutron profile monitor ensures 2D coverage of the gamma and neutron emissive region that enables tomographic reconstruction. Due to the availability of only two projection angles and to the coarse sampling, tomographic inversion is a limited data set problem. Several techniques have been developed for tomographic reconstruction of the 2-D gamma and neutron emissivity on JET, but the problem of evaluating the errors associated with the reconstructed emissivity profile is still open. The reconstruction technique based on the maximum likelihood principle, that proved already to be a powerful tool for JET tomography, has been used to develop a method for the numerical evaluation of the statistical properties of the uncertainties in gamma and neutron emissivity reconstructions. The image covariance calculation takes into account the additional techniques introduced in the reconstruction process for tackling with the limited data set (projection resampling, smoothness regularization depending on magnetic field). The method has been validated by numerically simulations and applied to JET data. Different sources of artefacts that may significantly influence the quality of reconstructions and the accuracy of variance calculation have been identified.

  10. NEUTRON CROSS SECTION EVALUATIONS OF FISSION PRODUCTS BELOW THE FAST ENERGY REGION

    SciTech Connect

    OH,S.Y.; CHANG,J.; MUGHABGHAB,S.

    2000-05-11

    Neutron cross section evaluations of the fission-product isotopes, {sup 95}Mo, {sup 99}Tc, {sup 101}Ru, {sup 103}Rh, {sup 105}Pd, {sup 109}Ag, {sup 131}Xe, {sup 133}Cs, {sup 141}Pr, {sup 141}Nd, {sup 147}Sm, {sup 149}Sm, {sup 150}Sm, {sup 151}Sm, {sup 152}Sm, {sup 153}Eu, {sup 155}Gd, and {sup 157}Gd were carried out below the fast neutron energy region within the framework of the BNL-KAERI international collaboration. In the thermal energy region, the energy dependence of the various cross-sections was calculated by applying the multi-level Breit-Wigner formalism. In particular, the strong energy dependence of the coherent scattering lengths of {sup 155}Gd and {sup 157}Gd were determined and were compared with recent calculations of Lynn and Seeger. In the resonance region, the recommended resonance parameters, reported in the BNL compilation, were updated by considering resonance parameter information published in the literature since 1981. The s-wave and, if available, p-wave reduced neutron widths were analyzed in terms of the Porter-Thomas distribution to determine the average level spacings and the neutron strength functions. Average radiative widths were also calculated from measured values of resolved energy resonances. The average resonance parameters determined in this study were compared with those in the BNL and other compilations, as well as the ENDF/B-VI, JEF-2.2, and JENDL-3.2 data libraries. The unresolved capture cross sections of these isotopes, computed with the determined average resonance parameters, were compared with measurements, as well as the ENDF/B-VI evaluations. To achieve agreement with the measurements, in a few cases minor adjustments in the average resonance parameters were made. Because of astrophysical interest, the Maxwellian capture cross sections of these nuclides at a neutron temperature of 30 keV were computed and were compared with other compilations and evaluations.

  11. Preliminary ANS (Advanced Neutron Source) reactor cold source gain factor calculations for liquid deuterium and liquid nitrogen-15

    SciTech Connect

    Henderson, D.L.

    1988-11-01

    Individual energy group gain factors are computed for liquid nitrogen-15 and liquid deuterium cold source moderators using simple one-dimensional slab and spherical geometry calculational models. The energy spectrum of the neutron source is assumed to be that of a thermalized Maxwellian flux at 20/degree/C. The slab geometry calculations indicate that the optimum thickness for neutron transmission through a slab given an isotropic incident flux is for wavelengths above .6 nm, approximately .20 m for liquid deuterium and between .28 and .32 m for liquid nitrogen-15. The gain factors at .8 nm corresponding to these thicknesses are 15.5 for liquid deuterium and 3.50 for liquid nitrogen-15. The spherical geometry analysis showed that the cold neutron current below 10 MeV of 1.36 n/m/sup 2/-s for the neutron component entering the cavity of a .16 m thick liquid deuterium spherical shell exceeds the neutron leakage current of 1.08 n/cm/sup 2/-s from a .38 m diameter liquid deuterium solid sphere. However, the cold neutron factors for the neutron entering the void region are considerably lower than for the solid sphere case. 15 refs., 24 figs., 7 tabs.

  12. Evaluation of neutron background in cryogenic Germanium target for WIMP direct detection when using reactor neutrino detector as neutron veto

    NASA Astrophysics Data System (ADS)

    Xu, Ye; Lan, Jieqin; Bai, Ying; Gao, Weiwei

    2016-09-01

    A direct WIMP (Weakly Interacting Massive Particle) detector with a neutron veto system is designed to better reject neutrons. An experimental configuration is studied in the present paper: 984 Ge modules are placed inside a reactor neutrino detector. In order to discriminate between nuclear and electron recoil, both ionization and heat signatures are measured using cryogenic germanium detectors in this detection. The neutrino detector is used as a neutron veto device. The neutron background for the experimental design has been estimated using the Geant4 simulation. The results show that the neutron background can decrease to O(0.01) events per year per tonne of high purity Germanium. We calculate the sensitivity to spin-independent WIMP-nucleon elastic scattering. An exposure of one tonne × year could reach a cross-section of about 2×10-11 pb.

  13. Evaluation of the neutron cross sections for Pu-240

    SciTech Connect

    Weston, L.W.; Arthur, E.D.

    1987-04-01

    The present evaluation is proposed to supersede the ENDF/B-V, Revision 2 file for /sup 240/Pu. In this work, resonance parameters, cross sections, energy distributions, and angular distributions have been modified. These changes are outlined in detail and appropriate references included. 37 refs., 21 figs., 2 tabs.

  14. Preliminary evaluation of wind energy potential: Cook Inlet area, Alaska

    SciTech Connect

    Hiester, T.R.

    1980-06-01

    This report summarizes work on a project performed under contract to the Alaska Power Administration (APA). The objective of this research was to make a preliminary assessment of the wind energy potential for interconnection with the Cook Inlet area electric power transmission and distribution systems, to identify the most likely candidate regions (25 to 100 square miles each) for energy potential, and to recommend a monitoring program sufficient to quantify the potential.

  15. Background evaluation for the neutron sources in the Daya Bay experiment

    NASA Astrophysics Data System (ADS)

    Gu, W. Q.; Cao, G. F.; Chen, X. H.; Ji, X. P.; Li, G. S.; Ling, J. J.; Liu, J.; Qian, X.; Wang, W.

    2016-10-01

    We present an evaluation of the background induced by 241Am-13C neutron calibration sources in the Daya Bay reactor neutrino experiment. As a significant background for electron-antineutrino detection at 0.26 ± 0.12 per detector per day on average, it has been estimated by a Monte Carlo simulation that was benchmarked by a special calibration data set. This dedicated data set also provides the energy spectrum of the background.

  16. Background evaluation for the neutron sources in the Daya Bay experiment

    DOE PAGES

    Gu, W. Q.; Cao, G. F.; Chen, X. H.; ...

    2016-07-06

    Here, we present an evaluation of the background induced by 241Am–13C neutron calibration sources in the Daya Bay reactor neutrino experiment. Furthermore, as a significant background for electron-antineutrino detection at 0.26 ± 0.12 detector per day on average, it has been estimated by a Monte Carlo simulation that was benchmarked by a special calibration data set. This dedicated data set also provides the energy spectrum of the background.

  17. Evaluation of Silicon Neutron Resonance Parameters in the Energy Range Thermal to 1800 keV

    SciTech Connect

    Derrien, H.

    2002-09-30

    The evaluation of the neutron cross sections of the three stable isotopes of silicon in the energy range thermal to 20 MeV was performed by Hetrick et al. for ENDF/B-VI (Evaluated Nuclear Data File). Resonance parameters were obtained in the energy range thermal to 1500 keV from a SAMMY analysis of the Oak Ridge National Laboratory experimental neutron transmission data. A new measurement of the capture cross section of natural silicon in the energy range 1 to 700 keV has recently been performed at the Oak Ridge Electron Linear Accelerator. Results of this measurement were used in a SAMMY reevaluation of the resonance parameters, allowing determination of the capture width of a large number of resonances. The experimental data base is described; properties of the resonance parameters are given. For the first time the direct neutron capture component has been taken into account from the calculation by Rauscher et al. in the energy range from thermal to 1 MeV. Results of benchmark calculations are also given. The new evaluation is available in the ENDF/B-VI format.

  18. Neutron Capture Cross Sections of 236U and 234U

    SciTech Connect

    Rundberg, R. S.; Bredeweg, T. A.; Bond, E. M.; Haight, R. C.; Hunt, L. F.; O'Donnell, J. M.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Kronenberg, A.

    2006-03-13

    Accurate neutron capture cross sections of the actinide elements at neutron energies up to 1 MeV are needed to better interpret archived nuclear test data, for post-detonation nuclear attribution, and the Advanced Fuel Cycle Initiative. The Detector for Advance Neutron Capture Experiments, DANCE, has unique capabilities that allow the differentiation of capture gamma rays from fission gamma rays and background gamma rays from scattered neutrons captured by barium isotopes in the barium fluoride scintillators. The DANCE array has a high granularity, 160 scintillators, high efficiency, and nearly 4-{pi} solid angle. Through the use of cuts in cluster multiplicity and calorimetric energy the capture gamma-rays are differentiated from other sources of gamma rays. The preliminary results for the capture cross sections of 236U are in agreement with the ENDF/B-VI evaluation. The preliminary results for 234U lower are than ENDF/B-VI evaluation and are closer to older evaluations.

  19. Evaluation of Am-Li neutron spectra data for active well type neutron multiplicity measurements of uranium

    NASA Astrophysics Data System (ADS)

    Goddard, Braden; Croft, Stephen; Lousteau, Angela; Peerani, Paolo

    2016-09-01

    Safeguarding nuclear material is an important and challenging task for the international community. One particular safeguards technique commonly used for uranium assay is active neutron correlation counting. This technique involves irradiating unused uranium with (α, n) neutrons from an Am-Li source and recording the resultant neutron pulse signal which includes induced fission neutrons. Although this non-destructive technique is widely employed in safeguards applications, the neutron energy spectra from an Am-Li sources is not well known. Several measurements over the past few decades have been made to characterize this spectrum; however, little work has been done comparing the measured and theoretical spectra of various Am-Li sources to each other. This paper examines fourteen different Am-Li spectra, focusing on how these spectra affect simulated neutron multiplicity results using the code Monte Carlo N-Particle eXtended (MCNPX). Two measurement and simulation campaigns were completed using Active Well Coincidence Counter (AWCC) detectors and uranium standards of varying enrichment. The results of this work indicate that for standard AWCC measurements, the fourteen Am-Li spectra produce similar doubles and triples count rates. The singles count rates varied by as much as 20% between the different spectra, although they are usually not used in quantitative analysis, being dominated by scattering which is highly dependent on item placement.

  20. Evaluation of Am–Li neutron spectra data for active well type neutron multiplicity measurements of uranium

    SciTech Connect

    Goddard, Braden; Croft, Stephen; Lousteau, Angela; Peerani, Paolo

    2016-05-25

    Safeguarding nuclear material is an important and challenging task for the international community. One particular safeguards technique commonly used for uranium assay is active neutron correlation counting. This technique involves irradiating unused uranium with ( α,n) neutrons from an Am-Li source and recording the resultant neutron pulse signal which includes induced fission neutrons. Although this non-destructive technique is widely employed in safeguards applications, the neutron energy spectra from an Am-Li sources is not well known. Several measurements over the past few decades have been made to characterize this spectrum; however, little work has been done comparing the measured spectra of various Am-Li sources to each other. This paper examines fourteen different Am-Li spectra, focusing on how these spectra affect simulated neutron multiplicity results using the code Monte Carlo N-Particle eXtended (MCNPX). Two measurement and simulation campaigns were completed using Active Well Coincidence Counter (AWCC) detectors and uranium standards of varying enrichment. The results of this work indicate that for standard AWCC measurements, the fourteen Am-Li spectra produce similar doubles and triples count rates. Finally, the singles count rates varied by as much as 20% between the different spectra, although they are usually not used in quantitative analysis.

  1. Evaluation of Am–Li neutron spectra data for active well type neutron multiplicity measurements of uranium

    DOE PAGES

    Goddard, Braden; Croft, Stephen; Lousteau, Angela; ...

    2016-05-25

    Safeguarding nuclear material is an important and challenging task for the international community. One particular safeguards technique commonly used for uranium assay is active neutron correlation counting. This technique involves irradiating unused uranium with ( α,n) neutrons from an Am-Li source and recording the resultant neutron pulse signal which includes induced fission neutrons. Although this non-destructive technique is widely employed in safeguards applications, the neutron energy spectra from an Am-Li sources is not well known. Several measurements over the past few decades have been made to characterize this spectrum; however, little work has been done comparing the measured spectra ofmore » various Am-Li sources to each other. This paper examines fourteen different Am-Li spectra, focusing on how these spectra affect simulated neutron multiplicity results using the code Monte Carlo N-Particle eXtended (MCNPX). Two measurement and simulation campaigns were completed using Active Well Coincidence Counter (AWCC) detectors and uranium standards of varying enrichment. The results of this work indicate that for standard AWCC measurements, the fourteen Am-Li spectra produce similar doubles and triples count rates. Finally, the singles count rates varied by as much as 20% between the different spectra, although they are usually not used in quantitative analysis.« less

  2. A Preliminary Evaluation of Reach: Training Early Childhood Teachers to Support Children's Social and Emotional Development

    ERIC Educational Resources Information Center

    Conners-Burrow, Nicola A.; Patrick, Terese; Kyzer, Angela; McKelvey, Lorraine

    2017-01-01

    This paper describes the development, implementation and preliminary evaluation of the Reaching Educators and Children (REACH) program, a training and coaching intervention designed to increase the capacity of early childhood teachers to support children's social and emotional development. We evaluated REACH with 139 teachers of toddler and…

  3. Synthesis and evaluation of boron compounds for neutron capture therapy of malignant brain tumors

    SciTech Connect

    Soloway, A.H.; Barth, R.F.

    1990-01-01

    Boron neutron capture therapy offers the potentiality for treating brain tumors currently resistant to treatment. The success of this form of therapy is directly dependent upon the delivery of sufficient numbers of thermal-neutrons to tumor cells which possess high concentrations of B-10. The objective of this project is to develop chemical methodology to synthesize boron-containing compounds with the potential for becoming incorporated into rapidly-dividing malignant brain tumor cells and excluded from normal components of the brain and surrounding tissues, to develope biological methods for assessing the potential of the compound by use of cell culture or intratumoral injection, to develop analytical methodology for measuring boron in cells and tissue using direct current plasma atomic emission spectroscopy (DCP-AES) and alpha track autoradiography, to develop biochemical and HPLC procedures for evaluating compound uptake and tissue half-life, and to develop procedures required to assess both in vitro and vivo efficacy of BNCT with selected compounds.

  4. Evaluation of AGNI SFR core neutronics parameters with VESTA and ERANOS

    NASA Astrophysics Data System (ADS)

    Ecrabet, Fabrice; Haeck, Wim; Chaitanya Tadepalli, Sai

    2014-06-01

    This paper presents the calculation of core neutronics parameters for so called AGNI Sodium Fast Reactor (SFR) model performed with ERANOS code and Monte Carlo depletion interface software VESTA. The AGNI core has been developed at IRSN for its own R&D needs, i.e. to test performance of calculation codes for safety assessment of a generation IV SFR project. The ERANOS code is used as reference code for SFR core calculations at IRSN. In this work, VESTA calculations have been performed and compared with corresponding ERANOS results. These calculations have a double purpose: mastering the use of tools for the evaluation of SFR core static neutronics parameters and validate the use of VESTA for SFR cores.

  5. Oak Ridge Reservation site evaluation report for the Advanced Neutron Source

    SciTech Connect

    Sigmon, B.; Heitzman, A.C. Jr.; Morrissey, J.

    1990-03-01

    The Advanced Neutron Source (ANS) is a research reactor that is the US Department of Energy (DOE) plans to build for initial service late in this century. The primary purpose of the ANS is to provide a useable neutron flux for scattering experiments 5 to 10 times as a high as that generated by any existing research reactor, secondary purposes include production of a variety of transuranic and other isotopes and irradiation of materials. The ANS is proposed to be located on the DOE Oak Ridge Reservation (ORR) at Oak Ridge, Tennessee, and operated by the Oak Ridge National Laboratory (ORNL). This report documents the evaluation of alternative sites on the ORR and the selection of a site for the ANS.

  6. Boron neutron capture therapy for the treatment of cerebral gliomas. I. Theoretical evaluation of the efficacy of various neutron beams.

    PubMed

    Zamenhof, R G; Murray, B W; Brownell, G L; Wellum, G R; Tolpin, E I

    1975-01-01

    The technique of boron neutron capture therapy in the treatment of cerebral gliomas depends upon the selective loading of the tumor with a 10B-enriched compound and subsequent irradiation of the brain with low-energy neutrons. The charged particles produced in the 10B (n,alpha) 7Li reaction have ranges in tissue of less than 10 mum so that the dose distribution closely follows the 10B distribution even to the cellular level. The effectiveness of this therapy procedure is dependent not only on the 10B compound but on the spectral characteristics of the neutron source as well. Hence, an optimization of these characteristics will increase the chances of therapeutic success. Transport calculations using a neutral particle transport code have been made to determine the dose-depth distributions within a simple head phantom for five different incident neutron beams. Comparison of these beams to determine their relative therapeutic efficacy was made by the use of a maximum useable depth criterion. In particular, with presently available compounds, the MIT reactor (MITR) therapy beam (a) is not inferior to a pure thermal neutron beam, (b) would be marginally improved if its gamma-ray contamination were eliminated, (c) is superior to a partially 10B-filtered MITR beam, and (d) produces a maximum useable depth which is strongly dependent upon the tumor-to-blood ratio of 10B concentrations and weakly dependent upon the absolute 10B concentration in tumor. A pure epithermal neutron beam with a mean energy of 37 eV is shown to have close to the optimal characteristics for boron neutron capture therapy. Futhermore, these optimal characteristics can be approximated by a judiciously D2O moderated and 10B-filtered 252Cf neutron source. This tailored 252Cf source would have at least a 1.5 cm greater maximum useable depth than the MITR therapy beam for realistic 10B concentrations. However, at least one gram of 252Cf would be needed to make this a practical therapy source. If the

  7. Preliminary evaluation of fiber composite reinforcement of truck frame rails

    NASA Technical Reports Server (NTRS)

    Faddoul, J. R.

    1977-01-01

    The use of graphite fiber/resin matrix composite to effectively reinforce a standard steel truck frame rail is studied. A preliminary design was made and it was determined that the reinforcement weight could be reduced by a factor of 10 when compared to a steel reinforcement. A section of a 1/3 scale reinforced rail was fabricated to demonstrate low cost manufacturing techniques. The scale rail section was then tested and increased stiffness was confirmed. No evidence of composite fatigue was found after 500,000 cycles to a fiber stress of 34,000 psi. The test specimen failed in bending in a static test at a load 50 percent greater than that predicted for a non-reinforced rail.

  8. Fabrication and Preliminary Evaluation of Metal Matrix Microencapsulated Fuels

    SciTech Connect

    Terrani, Kurt A; Kiggans, Jim; Snead, Lance Lewis

    2012-01-01

    The metal matrix microencapsulated (M3) fuel concept for light water reactors (LWRs), consisting of coated fuel particles dispersed in a zirconium metal matrix, is introduced. Fabrication of M3 fuels by hot pressing, hot isostatic pressing, or extrusion methodologies has been demonstrated over the temperature range 800-1050 C. Various types of coated fuel particles with outermost layers of pyrocarbon, SiC, ZrC, and TiN have been incorporated into the zirconium metal matrix. Mechanical particle-particle and chemical particle-matrix interactions have been observed during the preliminary characterization of as-fabricated M3 specimens. Irradiation of three M3 rodlets with surrogate coated fuel particles was carried out at mean rod temperature of 400 C to 4.6 dpa in the zirconium metal matrix. Due to absence of texture in the metal matrix no irradiation growth strain (<0.09%) was detected during the post-irradiation examination.

  9. Measurements of the thermal neutron flux for an accelerator-based photoneutron source.

    PubMed

    Taheri, Ali; Pazirandeh, Ali

    2016-12-01

    To have access to an appropriate neutron source is one of the most demanding requirements for neutron studies. This is important specially in laboratory and clinical applications, which need more compact and accessible sources. The most known neutron sources are fission reactors and natural isotopes, but there is an increasing interest for using accelerator based neutron sources because of their advantages. In this paper, we shall present a photo-neutron source prototype which is designed and fabricated to be used for different neutron researches including in-laboratory neutron activation analysis and neutron imaging, and also preliminary studies in boron neutron capture therapy (BNCT). Series of experimental tests were conducted to examine the intensity and quality of the neutron field produced by this source. Monte-Carlo simulations were also utilized to provide more detailed evaluation of the neutron spectrum, and determine the accuracy of the experiments. The experiments demonstrated a thermal neutron flux in the order of 10(7) (n/cm(2).s), while simulations affirmed this flux and showed a neutron spectrum with a sharp peak at thermal energy region. According to the results, about 60 % of produced neutrons are in the range of thermal to epithermal neutrons.

  10. National Evaluation of the Weatherization Assistance Program: Preliminary Evaluation Plan for Program Year 2006

    SciTech Connect

    Ternes, Mark P; Schweitzer, Martin; Tonn, Bruce Edward; Schmoyer, Richard L; Eisenberg, Joel Fred

    2007-02-01

    . For example, the use of computerized audits has increased, cooling and baseload measures have been added, weatherization approaches tailored to the unique construction characteristics of mobile homes have been developed, the weatherization of large multifamily buildings has expanded and become more sophisticated, the flexibility to improve 'energy-related' health and safety has been provided, and leveraging with utilities, other state programs, and owners of large multifamily buildings has increased considerably. The Department of Energy tasked ORNL with planning the new evaluation in light of its experience in conducting the previous national evaluation and the metaevaluations. This preliminary evaluation plan, developed by ORNL, documents how the new national evaluation will be performed. In the remaining portion of this section, the purpose and fundamental questions the evaluation will address are identified and how these questions were derived is discussed.

  11. Axial Neutron Flux Evaluation in a Tokamak System: a Possible Transmutation Blanket Position for a Fusion-Fission Transmutation System

    NASA Astrophysics Data System (ADS)

    Velasquez, Carlos E.; de P. Barros, Graiciany; Pereira, Claubia; Fortini Veloso, Maria A.; Costa, Antonella L.

    2012-08-01

    A sub-critical advanced reactor based on Tokamak technology with a D-T fusion neutron source is an innovative type of nuclear system. Due to the large number of neutrons produced by fusion reactions, such a system could be useful in the transmutation process of transuranic elements (Pu and minor actinides (MAs)). However, to enhance the MA transmutation efficiency, it is necessary to have a large neutron wall loading (high neutron fluence) with a broad energy spectrum in the fast neutron energy region. Therefore, it is necessary to know and define the neutron fluence along the radial axis and its characteristics. In this work, the neutron flux and the interaction frequency along the radial axis are evaluated for various materials used to build the first wall. W alloy, beryllium, and the combination of both were studied, and the regions more suitable to transmutation were determined. The results demonstrated that the best zone in which to place a transmutation blanket is limited by the heat sink and the shield block. Material arrangements of W alloy/W alloy and W alloy/beryllium would be able to meet the requirements of the high fluence and hard spectrum that are needed for transuranic transmutation. The system was simulated using the MCNP code, data from the ITER Final Design Report, 2001, and the Fusion Evaluated Nuclear Data Library/MC-2.1 nuclear data library.

  12. Advanced modeling of prompt fission neutrons

    SciTech Connect

    Talou, Patrick

    2009-01-01

    Theoretical and numerical studies of prompt fission neutrons are presented. The main results of the Los Alamos model often used in nuclear data evaluation work are reviewed briefly, and a preliminary assessment of uncertainties associated with the evaluated prompt fission neutron spectrum for n (0.5 MeV)+{sup 239}Pu is discussed. Advanced modeling of prompt fission neutrons is done by Monte Carlo simulations of the evaporation process of the excited primary fission fragments. The successive emissions of neutrons are followed in the statistical formalism framework, and detailed information, beyond average quantities, can be inferred. This approach is applied to the following reactions: {sup 252}Cf (sf), n{sub th} + {sup 239}Pu, n (0.5 MeV)+{sup 235}U, and {sup 236}Pu (sf). A discussion on the merits and present limitations of this approach concludes this presentation.

  13. Evaluation of Beta-Delayed Neutron Emission Probabilities and Half-Lives for Z = 2–28

    SciTech Connect

    Birch, M.; Singh, B.; Dillmann, I.; Abriola, D.; Johnson, T.D.; McCutchan, E.A.; Sonzogni, A.A.

    2015-09-15

    We present an evaluation and compilation of β-delayed neutron probabilities and half-lives for nuclei in the region Z = 2–28 ({sup 8}He–{sup 80}Ni). This article includes the recommended values of these quantities as well as a compiled list of experimental measurements for each nucleus in the region for which β-delayed neutron emission is possible. The literature cut-off for this work is August 15{sup th}, 2015. Some notable cases as well as new standards for β-delayed neutron measurements in this mass region are also discussed.

  14. Evaluation of a personal and environmental dosemeter based on CR-39 track detectors in quasi-monoenergetic neutron fields.

    PubMed

    Caresana, M; Ferrarini, M; Parravicini, A; Sashala Naik, A

    2014-10-01

    In this paper, the evaluation of the dosimetric capability of a detector based on a CR-39 solid-state nuclear track detector coupled to a 1 cm thickness of PMMA radiator was made with the aim of understanding the applicability of this technique to personal and environmental neutron dosimetry. The dosemeter has been exposed to monoenergetic and quasi-monoenergetic neutron beams at PTB in Braunschweig, Germany and at Ithemba Laboratories, in Faure, South Africa, with peak energies ranging from 0.565 to 100 MeV. The results showed a response that is almost independent of the neutron energy in the whole energy range.

  15. Micro-focused Small Angle Neutron Scattering and Imaging for Science and Engineering Using RTP--A Preliminary Study

    SciTech Connect

    Mohamed, Abdul Aziz; Al Rashid Megat Ahmad, Megat Harun; Md Idris, Faridah; Azman, Azraf; Jamro, Rafhayudi; Ibrahim, Mohd Rizal Mamat; Rahman, Anwar Abdul

    2010-01-05

    Malaysian Nuclear Agency's (Nuclear Malaysia) Small Angle Neutron Scattering (SANS) facility--(MYSANS)--is utilizing low flux of thermal neutron at the agency's 1 MW TRIGA reactor. As the design nature of the 8 m SANS facility can allow object resolution in the range between 5 and 80 nm to be obtained. It can be used to study alloys, ceramics and polymers in certain area of problems that relate to samples containing strong scatterers or contrast. The current SANS system at Malaysian Nuclear Agency is only capable to measure Q in limited range with a PSD (128x128) fixed at 4 m from the sample. The existing reactor hall that incorporate this MYSANS facility has a layout that prohibits the rebuilding of MYSANS therefore the position between the wavelength selector (HOPG) and sample and the PSD cannot be increased for wider Q range. The flux of the neutron at current sample holder is very low which around 10{sup 3} n/cm{sup 2}/sec. Thus it is important to rebuild the MYSANS to maximize the utilization of neutron. Over the years, the facility has undergone maintenance and some changes have been made. Modification on secondary shutter and control has been carried out to improve the safety level of the instrument. A compact micro-focus SANS method can suit this objective together with an improve cryostat system. This paper will explain some design concept and approaches in achieving higher flux and the modification needs to establish the micro-focused SANS.

  16. Evaluation of Neutron Radiography Reactor LEU-Core Start-Up Measurements

    SciTech Connect

    Bess, John D.; Maddock, Thomas L.; Smolinski, Andrew T.; Marshall, Margaret A.

    2014-11-04

    Benchmark models were developed to evaluate the cold-critical start-up measurements performed during the fresh core reload of the Neutron Radiography (NRAD) reactor with Low Enriched Uranium (LEU) fuel. Experiments include criticality, control-rod worth measurements, shutdown margin, and excess reactivity for four core loadings with 56, 60, 62, and 64 fuel elements. The worth of four graphite reflector block assemblies and an empty dry tube used for experiment irradiations were also measured and evaluated for the 60-fuel-element core configuration. Dominant uncertainties in the experimental keff come from uncertainties in the manganese content and impurities in the stainless steel fuel cladding as well as the 236U and erbium poison content in the fuel matrix. Calculations with MCNP5 and ENDF/B-VII.0 neutron nuclear data are approximately 1.4% (9σ) greater than the benchmark model eigenvalues, which is commonly seen in Monte Carlo simulations of other TRIGA reactors. Simulations of the worth measurements are within the 2σ uncertainty for most of the benchmark experiment worth values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.

  17. Evaluation of Neutron Radiography Reactor LEU-Core Start-Up Measurements

    DOE PAGES

    Bess, John D.; Maddock, Thomas L.; Smolinski, Andrew T.; ...

    2014-11-04

    Benchmark models were developed to evaluate the cold-critical start-up measurements performed during the fresh core reload of the Neutron Radiography (NRAD) reactor with Low Enriched Uranium (LEU) fuel. Experiments include criticality, control-rod worth measurements, shutdown margin, and excess reactivity for four core loadings with 56, 60, 62, and 64 fuel elements. The worth of four graphite reflector block assemblies and an empty dry tube used for experiment irradiations were also measured and evaluated for the 60-fuel-element core configuration. Dominant uncertainties in the experimental keff come from uncertainties in the manganese content and impurities in the stainless steel fuel cladding asmore » well as the 236U and erbium poison content in the fuel matrix. Calculations with MCNP5 and ENDF/B-VII.0 neutron nuclear data are approximately 1.4% (9σ) greater than the benchmark model eigenvalues, which is commonly seen in Monte Carlo simulations of other TRIGA reactors. Simulations of the worth measurements are within the 2σ uncertainty for most of the benchmark experiment worth values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.« less

  18. Preliminary Evaluation, Texas State Library Communication Network, 1968.

    ERIC Educational Resources Information Center

    Texas State Library, Austin. Field Services Div.

    In 1968 the Texas State Library established a library communications network under Title III of the Librar y Services and Construction Act. The objective of this study was to evaluate the network after six months of operation. Part I of the study consists of a general evaluation by Peat, Marwick, Mitchell and Co., based on operational data…

  19. Preliminary supersonic flight test evaluation of performance seeking control

    NASA Technical Reports Server (NTRS)

    Orme, John S.; Gilyard, Glenn B.

    1993-01-01

    Digital flight and engine control, powerful onboard computers, and sophisticated controls techniques may improve aircraft performance by maximizing fuel efficiency, maximizing thrust, and extending engine life. An adaptive performance seeking control system for optimizing the quasi-steady state performance of an F-15 aircraft was developed and flight tested. This system has three optimization modes: minimum fuel, maximum thrust, and minimum fan turbine inlet temperature. Tests of the minimum fuel and fan turbine inlet temperature modes were performed at a constant thrust. Supersonic single-engine flight tests of the three modes were conducted using varied after burning power settings. At supersonic conditions, the performance seeking control law optimizes the integrated airframe, inlet, and engine. At subsonic conditions, only the engine is optimized. Supersonic flight tests showed improvements in thrust of 9 percent, increases in fuel savings of 8 percent, and reductions of up to 85 deg R in turbine temperatures for all three modes. The supersonic performance seeking control structure is described and preliminary results of supersonic performance seeking control tests are given. These findings have implications for improving performance of civilian and military aircraft.

  20. Clinical laboratory evaluation of autoimmune autonomic ganglionopathy: Preliminary observations

    PubMed Central

    Goldstein, David S.; Holmes, Courtney; Imrich, Richard

    2014-01-01

    Several forms of chronic autonomic failure manifest as neurogenic orthostatic hypotension, including autoimmune autonomic ganglionopathy (AAG) and pure autonomic failure (PAF). AAG and PAF are thought to differ in pathogenesis, AAG reflecting decreased ganglionic neurotransmission due to circulating antibodies to the neuronal nicotinic receptor and PAF being a Lewy body disease with prominent loss of sympathetic noradrenergic nerves. AAG therefore would be expected to differ from PAF in terms of clinical laboratory findings indicating postganglionic noradrenergic denervation. Both diseases are rare. Here we report preliminary observations about clinical physiologic, neuropharmacologic, neurochemical, and neuroimaging data that seem to fit with the hypothesized pathogenetic difference between AAG and PAF. Patients with either condition have evidence of baroreflex–sympathoneural and baroreflex–cardiovagal failure. Both disorders feature low plasma levels of catecholamines during supine rest, but plasma levels of the other endogenous catechols, dihydroxyphenylalanine (DOPA), dihydroxyphenylacetic acid (DOPAC), and dihydroxyphenylglycol (DHPG), seem to be lower in PAF than in AAG, probably reflecting decreased norepinephrine synthesis and turnover in PAF, due to diffuse sympathetic noradrenergic denervation. PAF entails cardiac sympathetic denervation, whereas cardiac sympathetic neuroimaging by thoracic 6-[18F]fluorodopamine scanning indicates intact myocardial sympathetic innervation in AAG. PMID:19155193

  1. Development of a high spatial resolution neutron imaging system and performance evaluation

    NASA Astrophysics Data System (ADS)

    Cao, Lei

    The combination of a scintillation screen and a charged coupled device (CCD) camera is a digitized neutron imaging technology that has been widely employed for research and industry application. The maximum of spatial resolution of scintillation screens is in the range of 100 mum and creates a bottleneck for the further improvement of the overall system resolution. In this investigation, a neutron sensitive micro-channel plate (MCP) detector with pore pitch of 11.4 mum is combined with a cooled CCD camera with a pixel size of 6.8 mum to provide a high spatial resolution neutron imaging system. The optical path includes a high reflection front surface mirror for keeping the camera out of neutron beam and a macro lens for achieving the maximum magnification that could be achieved. All components are assembled into an aluminum light tight box with heavy radiation shielding to protect the camera as well as to provide a dark working condition. Particularly, a remote controlled stepper motor is also integrated into the system to provide on-line focusing ability. The best focus is guaranteed through use of an algorithm instead of perceptual observation. An evaluation routine not previously utilized in the field of neutron radiography is developed in this study. Routines like this were never previously required due to the lower resolution of other systems. Use of the augulation technique to obtain presampled MTF addresses the problem of aliasing associated with digital sampling. The determined MTF agrees well with the visual inspection of imaging a testing target. Other detector/camera combinations may be integrated into the system and their performances are also compared. The best resolution achieved by the system at the TRIGA Mark II reactor at the University of Texas at Austin is 16.2 lp/mm, which is equivalent to a minimum resolvable spacing of 30 mum. The noise performance of the device is evaluated in terms of the noise power spectrum (NPS) and the detective quantum

  2. Final evaluation of characterizing pipe-over-pack containers using high efficiency neutron counters

    SciTech Connect

    Carson, Pete; Stanfield, Sean B; Wachter, Joe; Cramer, Doug; Harvill, Joe

    2009-01-01

    Nondestructive assay (NDA) measurements of Transuranic (TRU) waste at Los Alamos National Laboratory (LANL) packed in Pipe-over-Pack Containers (POC) contain a number of complexities. The POC is highly attenuating to both gamma rays and neutrons which presents a difficult waste matrix for correct quantification of material in the container. Currently there are a number ofPOC containers at LANL that require evaluation for shipment to the Waste Isolation Pilot Plant (WIPP) in Carlsbad, NM. Updated data has been evaluated that finalizes the evaluation of characterizing Pipe-Over-Pack Containers. Currently at LANL, a single instrument has been used to explore the appropriateness of both passive neutron and quantitative gamma ray methods for measuring POC's. The passive neutron approach uses the Reals coincidence count rate to establish plutonium mass and other parameters of interest for TRU waste. The quantitative gamma ray method assumes a homogeneous distribution of radioactive source material with the surrounding material throughout the drum volume. Drums are assayed with a calibration based on the known density of the matrix. Both methods are supplemented by a simultaneous isotopic measurement using Multi-Group Analysis (MGA) to determine the plutonium isotopic composition. If MGA fails to provide a viable isotopic result Fixed Energy Response function Analysis with Multiple efficiencies (FRAM) has been used to replace the MGA results. Acceptable Knowledge (AK) may also be used in certain instances. This report will discuss the two methods in detail. Included in the discussion will be descriptions of the setup parameters and calibration techniques for the instrument. A number of test measurements have been performed to compare HENC data with certified historical data. Empty POCs loaded with known sources have also been measured to determine the viability of the technique. A comparison between calorimetry data, historical measurements and HENC data will also be

  3. Qualitative process evaluation of urban community work: a preliminary view.

    PubMed

    Chrisman, Noel J; Senturia, Kirsten; Tang, Gary; Gheisar, Bookda

    2002-04-01

    Community-based and participatory research have become significant activities during the past 15 years as public health practitioners and researchers have sought new ways to provide effective disease prevention and health promotion programs. It is also important that more examples of evaluation schemes be contributed for field testing. The process evaluation model offered here was based on an eclectic literature search because the evaluators did not know what directions this Centers for Disease Control and Prevention (CDC)-funded Urban Research Center would take and wanted to be thorough. Participatory action research using predominantly qualitative methods provided a research approach congruent with the capacity-building and power-sharing principles of the center. Seattle Partners for Healthy Communities is not a traditional community project, acting primarily as a broker for expertise and community needs. However, it has been successful in supporting and evaluating community health projects.

  4. Super-Efficient Refrigerator Program (SERP) evaluation volume 2: Preliminary impact and market transformation assessment

    SciTech Connect

    Lee, A.D.; Conger, R.L.

    1996-08-01

    The Super Efficient Refrigerator Program (SERP) is a collaborative utility program intended to transform the market for energy-efficient and environmentally friendly refrigerators. It is one of the first examples of a large-scale {open_quotes}market transformation{close_quotes} energy efficiency program. This report documents the preliminary impact and market transformation evaluation of SERP ({open_quotes}the Program{close_quotes}). Pacific Northwest National Laboratory (PNNL) conducted this evaluation for the U.S. Department of Energy. This study focuses on the preliminary impact evaluation and market transformation assessment, but also presents limited process evaluation information. It is based on interviews with refrigerator dealers and manufacturers, interviews with utility participants, industry data, and information from the Program administrators. Results from this study complement those from prior process evaluation also conducted by PNNL. 42 refs., 5 figs., 4 tabs.

  5. Quantitative fuel motion determination with the CABRI fast neutron hodoscope; Evaluation methods and results

    SciTech Connect

    Baumung, K. ); Augier, G. )

    1991-12-01

    The fast neutron hodoscope installed at the CABRI reactor in Cadarache, France, is employed to provide quantitative fuel motion data during experiments in which single liquid-metal fast breeder reactor test pins are subjected to simulated accident conditions. Instrument design and performance are reviewed, the methods for the quantitative evaluation are presented, and error sources are discussed. The most important findings are the axial expansion as a function of time, phenomena related to pin failure (such as time, location, pin failure mode, and fuel mass ejected after failure), and linear fuel mass distributions with a 2-cm axial resolution. In this paper the hodoscope results of the CABRI-1 program are summarized.

  6. Boron neutron capture therapy of the rat 9L gliosarcoma: evaluation of the effects of shark cartilage.

    PubMed

    Morris, G M; Coderre, J A; Micca, P L; Lombardo, D T; Hopewell, J W

    2000-04-01

    A number of anti-angiogenic substances are now under evaluation, both experimentally and clinically, as potential agents for the treatment of cancer. It has recently been demonstrated that anti-angiogenic agents can increase the therapeutic potential of photon irradiation in a range of tumour models. In the present communication a preliminary assessment is made of the effects of shark cartilage on the response of the rat 9L gliosarcoma to boron neutron capture therapy (BNCT). Shark cartilage was administered orally as an aqueous suspension at a daily dose of approximately 2000 mg kg-1 body weight. The mean survival time of rats receiving no treatment was 20.7 +/- 0.5 days post intracranial tumour implantation. Administration of shark cartilage alone extended the survival time. Two of the rats treated with shark cartilage were healthy and fully active at the end of the evaluation period (43 days post implantation). At autopsy the brain tumours of these animals were a factor of approximately 4 smaller than controls. In a repeat study with shark cartilage alone the survival time was extended by approximately 30%. After boronophenylalanine-mediated BNCT, with or without shark cartilage, the survival time of rats that eventually became moribund was increased by a factor of approximately 2 relative to controls. In both treatment groups approximately 20% of rats were healthy at 1 year after BNCT. There was no evidence of residual tumour at post-mortem. It was concluded that shark cartilage, when given alone, significantly increased the survival time of tumour-bearing rats, presumably owing to an anti-angiogenic effect. However, the survival data suggested that boronophenylalanine-mediated BNCT did not appear to be enhanced by the administration of shark cartilage.

  7. Neutron measurements

    SciTech Connect

    McCall, R.C.

    1981-01-01

    Methods of neutron detection and measurement are discussed. Topics include sources of neutrons, neutrons in medicine, interactions of neutrons with matter, neutron shielding, neutron measurement units, measurement methods, and neutron spectroscopy. (ACR)

  8. Evaluating secondary neutron doses of a refined shielded design for a medical cyclotron using the TLD approach

    NASA Astrophysics Data System (ADS)

    Lin, Jye-Bin; Tseng, Hsien-Chun; Liu, Wen-Shan; Lin, Ding-Bang; Hsieh, Teng-San; Chen, Chien-Yi

    2013-11-01

    An increasing number of cyclotrons at medical centers in Taiwan have been installed to generate radiopharmaceutical products. An operating cyclotron generates immense amounts of secondary neutrons from reactions such the 18O(p, n)18F, used in the production of FDG. This intense radiation can be hazardous to public health, particularly to medical personnel. To increase the yield of 18F-FDG from 4200 GBq in 2005 to 48,600 GBq in 2011, Chung Shan Medical University Hospital (CSMUH) has prolonged irradiation time without changing the target or target current to meet requirements regarding the production 18F. The CSMUH has redesigned the CTI Radioisotope Delivery System shield. The lack of data for a possible secondary neutron doses has increased due to newly designed cyclotron rooms. This work aims to evaluate secondary neutron doses at a CTI cyclotron center using a thermoluminescent dosimeter (TLD-600). Two-dimensional neutron doses were mapped and indicated that neutron doses were high as neutrons leaked through self-shielded blocks and through the L-shaped concrete shield in vault rooms. These neutron doses varied markedly among locations close to the H218O target. The Monte Carlo simulation and minimum detectable dose are also discussed and demonstrated the reliability of using the TLD-600 approach. Findings can be adopted by medical centers to identify radioactive hot spots and develop radiation protection.

  9. Preliminary data for the 20 May 1974, simultaneous evaluation of remote sensors experiment. [water pollution monitoring

    NASA Technical Reports Server (NTRS)

    Johnson, R. W.; Batten, C. E.; Bowker, D. E.; Bressette, W. E.; Grew, G. W.

    1975-01-01

    Several remote sensors were simultaneously used to collect data over the tidal James River from Hopewell to Norfolk, Virginia. Sensors evaluated included the Multichannel-Ocean Color Sensor, multispectral scanners, and multispectral photography. Ground truth measurements and remotely sensed data are given. Preliminary analysis indicates that suspended sediment and concentrated industrial effluent are observable from all sensors.

  10. A Preliminary Evaluation of Causal Models of Male and Female Acquisition of Pilot Skills

    DTIC Science & Technology

    1997-01-01

    Male and Female Causal Models...Clearance number 97-531 A Preliminary Evaluation of Causal Models of Male and Female Acquisition of Pilot Skills12 Thomas R. Carretta and Malcolm James...knowledge and flying skills was tested on separate samples of male and female students. Causal model parameters were estimated separately for each

  11. An Evaluation of Migrant Head Start Programs. Appendices. Preliminary Report on Home Base Findings.

    ERIC Educational Resources Information Center

    Reyes (J.A.) Associates, Inc., Washington, DC.

    Utilizing specially designed interview schedules to evaluate the kinds of services children and families receive from various Migrant Head Start programs throughout the country, this preliminary report on home base findings consists of questions asked of the staff at every Migrant Head Start site across the country and questions asked of parents…

  12. Preliminary Evaluation of an Aviation Safety Thesaurus' Utility for Enhancing Automated Processing of Incident Reports

    NASA Technical Reports Server (NTRS)

    Barrientos, Francesca; Castle, Joseph; McIntosh, Dawn; Srivastava, Ashok

    2007-01-01

    This document presents a preliminary evaluation the utility of the FAA Safety Analytics Thesaurus (SAT) utility in enhancing automated document processing applications under development at NASA Ames Research Center (ARC). Current development efforts at ARC are described, including overviews of the statistical machine learning techniques that have been investigated. An analysis of opportunities for applying thesaurus knowledge to improving algorithm performance is then presented.

  13. A Preliminary Evaluation of Fast ForWord-Language as an Adjuvant Treatment in Language Intervention

    ERIC Educational Resources Information Center

    Fey, Marc E.; Finestack, Lizbeth H.; Gajewski, Byron J.; Popescu, Mihai; Lewine, Jeffrey D.

    2010-01-01

    Purpose: Fast ForWord-Language (FFW-L) is designed to enhance children's processing of auditory-verbal signals and, thus, their ability to learn language. As a preliminary evaluation of this claim, we examined the effects of a 5-week course of FFW-L as an adjuvant treatment with a subsequent 5-week conventional narrative-based language…

  14. Preliminary safety evaluation for the spent nuclear fuel project`s cold vacuum drying system

    SciTech Connect

    Garvin, L.J., Westinghouse Hanford

    1996-07-01

    This preliminary safety evaluation (PSE) considers only the Cold Vacuum Drying System (CVDS) facility and its mission as it relates to the integrated process strategy (WHC 1995). The purpose of the PSE is to identify those CBDS design functions that may require safety- class and safety-significant accident prevention and mitigation features.

  15. Description and Preliminary Training Evaluation of an Arc Welding Simulator. Research Report SRR 73-23.

    ERIC Educational Resources Information Center

    Abrams, Macy L.; And Others

    A prototype arc welding training simulator was designed to provide immediate, discriminative feedback and the capacity for concentrated practice. Two randomly selected groups of welding trainees were compared to evaluate the simulator, one group being trained using the simulator and the other using conventional practice. Preliminary data indicated…

  16. Preliminary Technical and Legal Evaluation of Disposing of Nonhazardous Oil Field Waste into Salt Caverns

    SciTech Connect

    Ayers, Robert C.; Caudle, Dan; Elcock, Deborah; Raivel, Mary; Veil, John; and Grunewald, Ben

    1999-01-21

    This report presents an initial evaluation of the suitability, feasibility, and legality of using salt caverns for disposal of nonhazardous oil field wastes. Given the preliminary and general nature of this report, we recognize that some of our findings and conclusions maybe speculative and subject to change upon further research on this topic.

  17. Preliminary joint X-ray and neutron protein crystallographic studies of ecDHFR complexed with folate and NADP+.

    PubMed

    Wan, Qun; Kovalevsky, Andrey Y; Wilson, Mark A; Bennett, Brad C; Langan, Paul; Dealwis, Chris

    2014-06-01

    A crystal of Escherichia coli dihydrofolate reductase (ecDHFR) complexed with folate and NADP+ of 4×1.3×0.7 mm (3.6 mm3) in size was obtained by sequential application of microseeding and macroseeding. A neutron diffraction data set was collected to 2.0 Å resolution using the IMAGINE diffractometer at the High Flux Isotope Reactor within Oak Ridge National Laboratory. A 1.6 Å resolution X-ray data set was also collected from a smaller crystal at room temperature. The neutron and X-ray data were used together for joint refinement of the ecDHFR-folate-NADP+ ternary-complex structure in order to examine the protonation state, protein dynamics and solvent structure of the complex, furthering understanding of the catalytic mechanism.

  18. Preliminary joint X-ray and neutron protein crystallographic studies of ecDHFR complexed with folate and NADP+

    PubMed Central

    Wan, Qun; Kovalevsky, Andrey Y.; Wilson, Mark A.; Bennett, Brad C.; Langan, Paul; Dealwis, Chris

    2014-01-01

    A crystal of Escherichia coli dihydrofolate reductase (ecDHFR) complexed with folate and NADP+ of 4 × 1.3 × 0.7 mm (3.6 mm3) in size was obtained by sequential application of microseeding and macroseeding. A neutron diffraction data set was collected to 2.0 Å resolution using the IMAGINE diffractometer at the High Flux Isotope Reactor within Oak Ridge National Laboratory. A 1.6 Å resolution X-ray data set was also collected from a smaller crystal at room temperature. The neutron and X-ray data were used together for joint refinement of the ecDHFR–folate–NADP+ ternary-complex structure in order to examine the protonation state, protein dynamics and solvent structure of the complex, furthering understanding of the catalytic mechanism. PMID:24915100

  19. Preliminary ride-quality evaluation of the HM.2 Hoverferry

    NASA Technical Reports Server (NTRS)

    Mcclurken, E. W., Jr.; Jacobson, I. D.; Kuhlthau, A. R.

    1974-01-01

    The results of a forty-minute exposure of the HM.2 Hoverferry are presented. Quantitative evaluations were made from aft seats on the starboard side for a sea state considered calm and visually estimated at one-half to one foot. Since this type of craft is sensitive to sea state, the conclusions are based on ideal conditions. Some drawings are included.

  20. Methodology for worker neutron exposure evaluation in the PDCF facility design.

    PubMed

    Scherpelz, R I; Traub, R J; Pryor, K H

    2004-01-01

    A project headed by Washington Group International is meant to design the Pit Disassembly and Conversion Facility (PDCF) to convert the plutonium pits from excessed nuclear weapons into plutonium oxide for ultimate disposition. Battelle staff are performing the shielding calculations that will determine appropriate shielding so that the facility workers will not exceed target exposure levels. The target exposure levels for workers in the facility are 5 mSv y(-1) for the whole body and 100 mSv y(-1) for the extremity, which presents a significant challenge to the designers of a facility that will process tons of radioactive material. The design effort depended on shielding calculations to determine appropriate thickness and composition for glove box walls, and concrete wall thicknesses for storage vaults. Pacific Northwest National Laboratory (PNNL) staff used ORIGEN-S and SOURCES to generate gamma and neutron source terms, and Monte Carlo (computer code for) neutron photon (transport) (MCNP-4C) to calculate the radiation transport in the facility. The shielding calculations were performed by a team of four scientists, so it was necessary to develop a consistent methodology. There was also a requirement for the study to be cost-effective, so efficient methods of evaluation were required. The calculations were subject to rigorous scrutiny by internal and external reviewers, so acceptability was a major feature of the methodology. Some of the issues addressed in the development of the methodology included selecting appropriate dose factors, developing a method for handling extremity doses, adopting an efficient method for evaluating effective dose equivalent in a non-uniform radiation field, modelling the reinforcing steel in concrete, and modularising the geometry descriptions for efficiency. The relative importance of the neutron dose equivalent compared with the gamma dose equivalent varied substantially depending on the specific shielding conditions and lessons

  1. Grazing incidence neutron optics

    NASA Technical Reports Server (NTRS)

    Gubarev, Mikhail V. (Inventor); Ramsey, Brian D. (Inventor); Engelhaupt, Darell E. (Inventor)

    2012-01-01

    Neutron optics based on the two-reflection geometries are capable of controlling beams of long wavelength neutrons with low angular divergence. The preferred mirror fabrication technique is a replication process with electroform nickel replication process being preferable. In the preliminary demonstration test an electroform nickel optics gave the neutron current density gain at the focal spot of the mirror at least 8 for neutron wavelengths in the range from 6 to 20 .ANG.. The replication techniques can be also be used to fabricate neutron beam controlling guides.

  2. Grazing Incidence Neutron Optics

    NASA Technical Reports Server (NTRS)

    Gubarev, Mikhail V. (Inventor); Ramsey, Brian D. (Inventor); Engelhaupt, Darell E. (Inventor)

    2013-01-01

    Neutron optics based on the two-reflection geometries are capable of controlling beams of long wavelength neutrons with low angular divergence. The preferred mirror fabrication technique is a replication process with electroform nickel replication process being preferable. In the preliminary demonstration test an electroform nickel optics gave the neutron current density gain at the focal spot of the mirror at least 8 for neutron wavelengths in the range from 6 to 20.ANG.. The replication techniques can be also be used to fabricate neutron beam controlling guides.

  3. Improving eating disorders mental health literacy: a preliminary evaluation of the "Should I say something?" workshop.

    PubMed

    Gratwick-Sarll, Kassandra; Bentley, Caroline

    2014-01-01

    A repeated measures, uncontrolled, preliminary evaluation of a single 3-hour workshop-"Should I Say Something?"-aimed at improving eating disorders mental health literacy, was conducted in a sample of 177 university undergraduates. Following participation in the workshop, significant increases in eating disorder recognition and knowledge, and significant decreases in stigmatizing attitudes, were reported by participants. Moreover, 85% of participants reported that they provided assistance to someone whom they suspected had a mental health condition, including an eating disorder, during the 3-month follow-up period. This study provides preliminary evidence that "Should I Say Something?" may be effective in improving the mental health literacy of young people.

  4. Preliminary Evaluation of Thematic Mapper Image Data Quality

    NASA Technical Reports Server (NTRS)

    Macdonald, R. B.; Hall, F. G.; Pitts, D. E.; Bizzell, R. M.; Yao, S.; Sorensen, C.; Reyna, E.; Carnes, J.

    1985-01-01

    Improvements in the ability to monitor renewable resources/vegegation due to improvements in the spatial, spectral and radiometric resolution of TM data were evaluated. Results presented from the first 4 months of analysis presented include: (1) geometric performance; (2) band-to-band registration; (3) modulation transfer function; and (4) crop separabililty performance. Crop separability in Webster County, Iowa and in Mississippi County, Arkansas as determined by cluster and principal components analyses is assessed.

  5. Real time evaluation of monolateral clubfoot with sonoelastography. Preliminary results

    PubMed Central

    Masala, Salvatore; Manenti, Guglielmo; Antonicoli, Marco; Morosetti, Daniele; Claroni, Giulia; Simonetti, Giovanni

    2012-01-01

    Summary Purpose: to assess the real time elastosonography (RTE) as a primary diagnostic tool for the evaluation of mechanical properties of Achilles tendons in patients affected by not surgically treated monolateral clubfoot. Materials and method: six patients were evaluated, four males and two females, mean age 1.2 ± 1.3 months, treated with Ponseti method, and afterward, they underwent RTE examination of the Achilles tendon in club-foot. A following ROI (region of interest) was positioned on the distal third of the tendon and the obtained data was examined retrospectively. Results: in the examined cohort of patients, the mean value ROI 1/mean value ROI 2 ratio was 2.0 ± 0.18, with an increased red area in the RTE evaluation of the affected tendon, while in the contralateral foot the mean observed value was 2.50 ± 2.1. Conclusion: RTE is a feasible and simple technique, which allows the study of the mechanical properties of Achilles tendons in children with clubfoot. PMID:23738274

  6. Efficacy of oleuropein against UVB irradiation: preliminary evaluation.

    PubMed

    Perugini, P; Vettor, M; Rona, C; Troisi, L; Villanova, L; Genta, I; Conti, B; Pavanetto, F

    2008-04-01

    Oleuropein, a phenolic compound derived from olive leaves and oil, is known to possess several biological properties, many of which may be attributed to its antioxidant and free radical-scavenging activities. Nevertheless, up to now, the cosmetic activity of this molecule has not been extensively investigated. The aim of this work was to evaluate the cosmetic properties of oleuropein against UVB-induced erythema. To this end, an emulsion and an emulgel containing oleuropein were prepared, applied and evaluated on healthy volunteers who had undergone UVB irradiation to investigate its protective and/or lenitive activity. Protective effect was assayed by application of topical preparations before irradiation and lenitive effect was evaluated after erythema induction. Vitamin E was used as the reference compound. Our study was carried out by using noninvasive techniques to assess specific skin parameters: barrier function, skin colour and microcirculation. Results clearly showed that oleuropein formulations highlighted lenitive efficacy by reducing erythema, transepidermal water loss and blood flow of about 22%, 35% and 30% respectively. The study allowed us to point out the lenitive property of oleuropein, opening the way to further trials to deepen our specific knowledge about this natural molecule, which could be used in association with other active ingredients in cosmetics to repair UV damages.

  7. Nondestructive evaluation of neutron irradiation embrittlement for reactor vessel steel by magnetomechanical acoustic emission technique

    SciTech Connect

    Maeda, Noriyoshi; Yamaguchi, Atsunori; Saito, Kiyoshi; Hirasawa, Taiji; Komura, Ichiroh; Chujou, Noriyuki

    1999-10-01

    A modified magnetomechanical acoustic emission (MAE) technique denoted Pulse MAE, in which the magnetizing current has a rectangular wave form, was developed as an NDE technique. Its applicability to the radiation damage for reactor pressure vessel steel was evaluated. The reactor pressure vessel steel A533B base metal and weld metal were irradiated to the two fluence levels: 5 {times} 10{sup 22} and 3 {times} 10{sup 23} n/m{sup 2} at 288 C. One side of the specimen was electropolished after irradiation. Pulse MAE signals were measured with a 350 kHz resonance frequency AE sensor at the moment when the magnetizing voltage is applied from zero to the set-up value abruptly. The AE signals were analyzed and the peak voltage Vp was determined for the measuring parameter. The peak voltage Vp showed the tendency to increase monotonically with increasing neutron fluence. The relationship between the Vp and mechanical properties such as yield stress, tensile strength and Charpy transition temperature were also obtained. The Pulse MAE technique proved to have the possibility to detect and evaluate the neutron irradiation embrittlement. The potential of the Pulse MAE as an effective NDE technique and applicability to the actual components are discussed.

  8. The use of the neutronic calculation code CORNER for evaluating the protection of fast neutron reactor and CNFC equipment

    NASA Astrophysics Data System (ADS)

    Shekhanova, M. E.

    2017-01-01

    In this paper we propose a method of using neutronic calculation code CORNER to the analysis of experiments on the protection of fast neutron reactor and CNFC equipment. An example of Winfrith Graphite Benchmark experiment calculation using this approach is presented. This task can be considered as one step in the general theme of the safety analysis of FR with liquid metal coolant, their fuel cycles and related equipment. CORNER implement a solution of the kinetic equation with a source in the three-dimensional hexagonal geometry based on Sn-method. The purpose of this paper is a demonstration of the application of CORNER’s possibilities for the analysis of the actual reactor problems.

  9. Preliminary field evaluation of high efficiency steel filters

    SciTech Connect

    Bergman, W.; Larsen, G.; Lopez, R.

    1995-02-01

    We have conducted an evaluation of two high efficiency steel filters in the exhaust of an uranium oxide grit blaster at the Y-12 Plant in Oak Ridge Tennessee. The filters were installed in a specially designed filter housing with a reverse air-pulse cleaning system for automatically cleaning the filters in-place. Previous tests conducted on the same filters and housing at LLNL under controlled conditions using Arizona road dust showed good cleanability with reverse air pulses. Two high efficiency steel filters, containing 64 pleated cartridge elements housed in the standard 2` x 2` x 1` HEPA frame, were evaluated in the filter test housing using a 1,000 cfm slip stream containing a high concentration of depleted uranium oxide dust. One filter had the pleated cartridges manufactured to our specifications by the Pall Corporation and the other by Memtec Corporation. Test results showed both filters had a rapid increase in pressure drop with time, and reverse air pulses could not decrease the pressure drop. We suspected moisture accumulation in the filters was the problem since there were heavy rains during the evaluations, and the pressure drop of the Memtec filter decreased dramatically after passing clean, dry air through the filter and after the filter sat idle for one week. Subsequent laboratory tests on a single filter cartridge confirmed that water accumulation in the filter was responsible for the increase in filter pressure drop and the inability to lower the pressure drop by reverse air pulses. No effort was made to identify the source of the water accumulation and correct the problem because the available funds were exhausted.

  10. World Opinion and the Soviet Satellite: A Preliminary Evaluation

    NASA Technical Reports Server (NTRS)

    1957-01-01

    Less than two weeks after the launch of Sputnik I, the United States Information Agency conducted an informal analysis of public opinion on this subject. The analysis yielded four clear conclusions: (1) Soviet claims of scientific and technological superiority were widely accepted in the United States; (2) U.S. allies were concerned about a shift in the balance of military power; (3) the overall credibility of Soviet propaganda was greatly strengthened; and (4) American prestige was dealt a severe blow. The report also concluded that the near-hysteria in the United States in turn increased the level of concern in countries friendly to the United States. An evaluation is presented.

  11. Preliminary flight evaluation of an engine performance optimization algorithm

    NASA Technical Reports Server (NTRS)

    Lambert, H. H.; Gilyard, G. B.; Chisholm, J. D.; Kerr, L. J.

    1991-01-01

    A performance seeking control (PSC) algorithm has undergone initial flight test evaluation in subsonic operation of a PW 1128 engined F-15. This algorithm is designed to optimize the quasi-steady performance of an engine for three primary modes: (1) minimum fuel consumption; (2) minimum fan turbine inlet temperature (FTIT); and (3) maximum thrust. The flight test results have verified a thrust specific fuel consumption reduction of 1 pct., up to 100 R decreases in FTIT, and increases of as much as 12 pct. in maximum thrust. PSC technology promises to be of value in next generation tactical and transport aircraft.

  12. Preliminary evaluation of a space AMTEC power conversion system

    NASA Technical Reports Server (NTRS)

    Crowley, Christopher J.; Sievers, Robert K.

    1991-01-01

    As original evaluation of a space solar energy source coupled with Alkali Metal Thermoelectric Conversion (AMTEC) is presented here. This study indicates that an AMTEC system would have 30 percent of the mass of a photovoltaic system and 70 percent of the mass of a Stirling cycle system at the 35-kWe level of power generation modules typical of the baseline for the U.S. Space Station. The operating temperatures and sodium heat pipe components for solar receiver/TES hardware (currently being developed by NASA) integrate well with AMTEC power conversion. AMTEC is therefore an attractive alternative specifically for space solar power generation.

  13. Preliminary surface-emitting laser logic device evaluation

    NASA Astrophysics Data System (ADS)

    Libby, S. I.; Parker, M. A.; Olbright, G. R.; Swanson, P. D.

    1993-03-01

    This report discusses the evaluation of a monolithically integrated heterojunction phototransistor and vertical-cavity surface-emitting laser, designated the surface-Emitting Laser Logic device (CELL). Included is a discussion of the device structure and theory of operation, test procedures, results, and conclusions. Also presented is the CELL's opto-electronic input/output characteristics which includes spectral analysis, characteristic emitted light versus current and current versus voltage curves, input wavelength tolerance, output wavelength sensitivity to bias current, and insensitivity to input wavelength and power within a specified range.

  14. Preliminary evaluation of a proposed injection site in Mellones

    SciTech Connect

    Ortiz, N.V.; Rada, H.M.

    1996-08-01

    A hydrogeological evaluation was carried out in the Melones area to determine the feasibility of disposing brackish water and brines associated with oil production activities. The region is located towards north-central Hamaca, in the Anzoategui state, and covers an area of approximately 454 km{sup 2}. The study was based on the examination and interpretation of available stratigraphic and structural maps, well logs and formation water analysis. Engineering properties were estimated from 42 wells, selected from a total of 575 wells, where complete sets of well logs were available. The most suitable injection interval, integrated by the 02/3, D1-D2-D3-D4 and E1-E2 sands from the upper part of the Oficina Formation, was selected by addressing certain technical requirements for suitable potential disposal sites and injection intervals. A two-dimensional finite difference flow model was used to simulate the long-term hydraulic head buildup under projected operating conditions. After examination of the important characteristics considered in the evaluation process, it appears that the Melones area favorably meets most criteria.

  15. Restoring accommodation: surgical technique and preliminary evaluation in rabbits

    NASA Astrophysics Data System (ADS)

    Tahi, Hassan; Chapon, Pascal F.; Hamaoui, Marie; Lee, William E.; Holden, Brien; Parel, Jean-Marie A.

    1999-06-01

    Purpose. To evaluate an innovative surgical technique for phaco-ersatz, a cataract surgery designed to restore accommodation. Techniques for very small capsulorhexis as well as the refilling procedure were developed. This study evaluates the feasibility and reproducibility of the surgical technique. Methods. The right eye of 8 NZW rabbits (~ 2 Kg) were operated following the ARVO Statements for the Use of Animals in Ophthalmic and Vision Research. The surgery is begun by making a small peripheral capsulorhexis of about 1 mm using. The lens content is then removed. The lens is then refilled with a novel in situ polymerizable gel and the corneal incision is closed using one 10/0 Nylon interrupted stitch. Results. The capsulorhexis technique was succesfully performed and reproducible in all animals. The average size of the capsulorhexis opening was 1. 2 mm (+/-0.14). Lens material removal and refilling of the capsular bag with an in situ polymerizable material was also performed in each trial study. Conclusion. This surgical technique seemed feasible and reproducible.

  16. Bayesian Evaluation Including Covariance Matrices of Neutron-induced Reaction Cross Sections of {sup 181}Ta

    SciTech Connect

    Leeb, H. Schnabel, G.; Srdinko, Th.; Wildpaner, V.

    2015-01-15

    A new evaluation of neutron-induced reactions on {sup 181}Ta using a consistent procedure based on Bayesian statistics is presented. Starting point of the evaluation is the description of nuclear reactions via nuclear models implemented in TALYS 1.4. A retrieval of experimental data was performed and covariance matrices of the experiments were generated from an extensive study of the corresponding literature. All reaction channels required for a transport file up to 200 MeV have been considered and the covariance matrices of cross section uncertainties for the most important channels are determined. The evaluation has been performed in one step including all available experimental data. A comparison of the evaluated cross sections and spectra with experimental data and available evaluations is performed. In general the evaluated cross section reflect our best knowledge and give a fair description of the observables. However, there are few deviations from expectation which clearly indicate the impact of the prior and the need to account for model defects. Using the results of the evaluation a complete ENDF-file similarly to those of the TENDL library is generated.

  17. SELECTION AND PRELIMINARY EVALUATION OF ALTERNATIVE REDUCTANTS FOR SRAT PROCESSING

    SciTech Connect

    Stone, M.; Pickenheim, B.; Peeler, D.

    2009-06-30

    Defense Waste Processing Facility - Engineering (DWPF-E) has requested the Savannah River National Laboratory (SRNL) to perform scoping evaluations of alternative flowsheets with the primary focus on alternatives to formic acid during Chemical Process Cell (CPC) processing. The reductants shown below were selected for testing during the evaluation of alternative reductants for Sludge Receipt and Adjustment Tank (SRAT) processing. The reductants fall into two general categories: reducing acids and non-acidic reducing agents. Reducing acids were selected as direct replacements for formic acid to reduce mercury in the SRAT, to acidify the sludge, and to balance the melter REDuction/OXidation potential (REDOX). Non-acidic reductants were selected as melter reductants and would not be able to reduce mercury in the SRAT. Sugar was not tested during this scoping evaluation as previous work has already been conducted on the use of sugar with DWPF feeds. Based on the testing performed, the only viable short-term path to mitigating hydrogen generation in the CPC is replacement of formic acid with a mixture of glycolic and formic acids. An experiment using glycolic acid blended with formic on an 80:20 molar basis was able to reduce mercury, while also targeting a predicted REDuction/OXidation (REDOX) of 0.2 expressed as Fe{sup 2+}/{Sigma}Fe. Based on this result, SRNL recommends performing a complete CPC demonstration of the glycolic/formic acid flowsheet followed by a design basis development and documentation. Of the options tested recently and in the past, nitric/glycolic/formic blended acids has the potential for near term implementation in the existing CPC equipment providing rapid throughput improvement. Use of a non-acidic reductant is recommended only if the processing constraints to remove mercury and acidify the sludge acidification are eliminated. The non-acidic reductants (e.g. sugar) will not reduce mercury during CPC processing and sludge acidification would

  18. Preliminary process engineering evaluation of ethanol production from vegetative crops

    NASA Astrophysics Data System (ADS)

    Moreira, A. R.; Linden, J. C.; Smith, D. H.; Villet, R. H.

    1982-12-01

    Vegetative crops show good potential as feedstock for ethanol production via cellulose hydrolysis and yeast fermentation. The low levels of lignin encountered in young plant tissues show an inverse relationship with the high cellulose digestibility during hydrolysis with cellulose enzymes. Ensiled sorghum species and brown midrib mutants of sorghum exhibit high glucose yields after enzyme hydrolysis as well. Vegetative crop materials as candidate feedstocks for ethanol manufacture should continue to be studied. The species studied so far are high value cash crops and result in relatively high costs for the final ethanol product. Unconventional crops, such as pigweed, kochia, and Russian thistle, which can use water efficiently and grow on relatively arid land under conditions not ideal for food production, should be carefully evaluated with regard to their cultivation requirements, photosynthesis rates, and cellulose digestibility. Such crops should result in more favorable process economics for alcohol production.

  19. Preliminary assessment of the nuclide migration from the activation zone around the proposed Spallation Neutron Source facility

    SciTech Connect

    Dole, L.R.

    1998-09-01

    The purpose of this study is to investigate the potential impacts of migrating radionuclides from the activation zone around the proposed Spallation Neutron Source (SNS). Using conservatively high estimates of the potential inventory of radioactive activation products that could form in the proposed compacted-soil shield berm around an SNS facility on the Oak Ridge Reservation (ORR), a conservative, simplified transport model was used to estimate the potential worst-case concentrations of the 12 long-lived isotopes in the groundwater under a site with the hydrologic characteristics of the ORR.

  20. Impact of the γ _{ν }NN* Electrocoupling Parameters at High Photon Virtualities and Preliminary Cross Sections off the Neutron

    NASA Astrophysics Data System (ADS)

    Gothe, Ralf W.; Tian, Ye

    2016-10-01

    Meson-photoproduction measurements and their reaction-amplitude analyses can establish more sensitively, and in some cases in an almost model-independent way, nucleon excitations and non-resonant reaction amplitudes. However, to investigate the strong interaction from already explored—where meson-cloud degrees of freedom contribute substantially to the baryon structure—to still unexplored distance scales—where quark degrees of freedom dominate and the transition from dressed to current quarks occurs—we depend on experiments that allow us to measure observables that are probing this evolving non-perturbative QCD regime over its full range. Elastic and transition form factors are uniquely suited to trace this evolution by measuring elastic electron scattering and exclusive single-meson and double-pion electroproduction cross sections off the nucleon. These exclusive measurements will be extended to higher momentum transfers with the energy-upgraded CEBAF beam at JLab to study the quark degrees of freedom, where their strong interaction is responsible for the ground and excited nucleon state formations. After establishing unprecedented high-precision data, the imminent next challenge is a high-quality analysis to extract these relevant electrocoupling parameters for various resonances that can then be compared to state-of-the-art models and QCD-based calculations. The vast majority of the available exclusive electroproduction cross sections are off the proton. Hence flavor-dependent analyses of excited light-quark baryons are lacking experimental data off the neutron. The goal is to close this gap by providing exclusive {γ }_{ν }(n) → p+ {π }- reaction cross section off deuterium and to establish a kinematical final-state-interaction (FSI) correction factor (R) map that can be determined from the data set itself. The "e1e" Jefferson Lab CLAS data set, that is analyzed, includes both a hydrogen and deuterium target run period, which allows a combined

  1. Evaluating fatigue in lupus-prone mice: preliminary assessments.

    PubMed

    Meeks, Allison; Larson, Susan J

    2012-01-01

    Fatigue is a debilitating condition suffered by many as the result of chronic disease, yet relatively little is known about its biological basis or how to effectively manage its effects. This study sought to evaluate chronic fatigue by using lupus-prone mice and testing them at three different time periods. Lupus-prone mice were chosen because fatigue affects over half of patients with Systemic Lupus Erythematosus. Eleven MLR⁺/(+) (genetic controls) and twelve MLR/MpJ-Fas/J (MRL/lpr; lupus-prone) mice were tested three times: once at 12, 16 and 20 weeks of age. All mice were subjected to a variety of behavioral tests including: forced swim, post-swim grooming, running wheel, and sucrose consumption; five of the MLR⁺/(+) and five of the MLR/lpr mice were also tested on a fixed ratio-25 operant conditioning task. MRL/lpr mice showed more peripheral symptoms of lupus than controls, particularly lymphadenopathy and proteinuria. Lupus mice spent more time floating during the forced swim test and traveled less distance in the running wheel at each testing period. There were no differences between groups in post-swim grooming or in number of reinforcers earned in the operant conditioning task indicating the behavioral changes were not likely due simply to muscle weakness or motivation. Correlations between performance in the running wheel, forced swim test and sucrose consumption were conducted and distance traveled in the running wheel was consistently negatively correlated with time spent floating. Based on these data, we conclude that the lupus-prone mice were experiencing chronic fatigue and that running wheel activity and floating during a forced swim test can be used to evaluate fatigue, although these data cannot rule out the possibility that both fatigue and a depressive-like state were mediating these effects.

  2. Preliminary resolved resonance region evaluation of copper-63 from 0 to 300 keV

    SciTech Connect

    Sobes, V.; Forget, B.; Leal, L.; Guber, K.

    2012-07-01

    A new preliminary evaluation of Cu-63 was done in the energy region from 0 to 300 keV extending the resolved resonance region of the previous, ENDF/B-VII.0, evaluation three-fold. The new evaluation was based on three experimental transmission data sets; two measured at the Oak Ridge Electron Linear Accelerator (ORELA) and one from the Massachusetts Inst. of Technology Nuclear Reactor (MITR). A total of 275 new resonances were identified and a corresponding set of external resonances was approximated to mock up the external levels. The negative external levels (bound level) were modified to match the thermal cross section values. A preliminary benchmarking calculation was made using 11 ICSBEP benchmarks. This work is in support of the DOE Nuclear Criticality Safety Program. (authors)

  3. NDP (Neutron Depth Profiling) Evaluations of Boron-Implanted Compound Semiconductors,

    DTIC Science & Technology

    1988-03-04

    This report describes recent neutron depth profiling (NDP) experiments on the distribution of implanted boron in several semiconductors. The...that were used to remove implant damage and electrically activate the boron. Keywords: Ion implants, Compound semiconductors, Neutron depth profiling .

  4. Evaluation of the ²³⁹Pu prompt fission neutron spectrum induced by neutrons of 500 keV and associated covariances

    DOE PAGES

    Neudecker, D.; Talou, P.; Kawano, T.; ...

    2015-08-01

    We present evaluations of the prompt fission neutron spectrum (PFNS) of ²³⁹Pu induced by 500 keV neutrons, and associated covariances. In a previous evaluation by Talou et al. 2010, surprisingly low evaluated uncertainties were obtained, partly due to simplifying assumptions in the quantification of uncertainties from experiment and model. Therefore, special emphasis is placed here on a thorough uncertainty quantification of experimental data and of the Los Alamos model predicted values entering the evaluation. In addition, the Los Alamos model was extended and an evaluation technique was employed that takes into account the qualitative differences between normalized model predicted valuesmore » and experimental shape data. These improvements lead to changes in the evaluated PFNS and overall larger evaluated uncertainties than in the previous work. However, these evaluated uncertainties are still smaller than those obtained in a statistical analysis using experimental information only, due to strong model correlations. Hence, suggestions to estimate model defect uncertainties are presented, which lead to more reasonable evaluated uncertainties. The calculated keff of selected criticality benchmarks obtained with these new evaluations agree with each other within their uncertainties despite the different approaches to estimate model defect uncertainties. The keff one standard deviations overlap with some of those obtained using ENDF/B-VII.1, albeit their mean values are further away from unity. Spectral indexes for the Jezebel critical assembly calculated with the newly evaluated PFNS agree with the experimental data for selected (n,γ) and (n,f) reactions, and show improvements for high-energy threshold (n,2n) reactions compared to ENDF/B-VII.1.« less

  5. Evaluation of the ²³⁹Pu prompt fission neutron spectrum induced by neutrons of 500 keV and associated covariances

    SciTech Connect

    Neudecker, D.; Talou, P.; Kawano, T.; Smith, D. L.; Capote, R.; Rising, M. E.; Kahler, A. C.

    2015-08-01

    We present evaluations of the prompt fission neutron spectrum (PFNS) of ²³⁹Pu induced by 500 keV neutrons, and associated covariances. In a previous evaluation by Talou et al. 2010, surprisingly low evaluated uncertainties were obtained, partly due to simplifying assumptions in the quantification of uncertainties from experiment and model. Therefore, special emphasis is placed here on a thorough uncertainty quantification of experimental data and of the Los Alamos model predicted values entering the evaluation. In addition, the Los Alamos model was extended and an evaluation technique was employed that takes into account the qualitative differences between normalized model predicted values and experimental shape data. These improvements lead to changes in the evaluated PFNS and overall larger evaluated uncertainties than in the previous work. However, these evaluated uncertainties are still smaller than those obtained in a statistical analysis using experimental information only, due to strong model correlations. Hence, suggestions to estimate model defect uncertainties are presented, which lead to more reasonable evaluated uncertainties. The calculated keff of selected criticality benchmarks obtained with these new evaluations agree with each other within their uncertainties despite the different approaches to estimate model defect uncertainties. The keff one standard deviations overlap with some of those obtained using ENDF/B-VII.1, albeit their mean values are further away from unity. Spectral indexes for the Jezebel critical assembly calculated with the newly evaluated PFNS agree with the experimental data for selected (n,γ) and (n,f) reactions, and show improvements for high-energy threshold (n,2n) reactions compared to ENDF/B-VII.1.

  6. Mortar radiocarbon dating: preliminary accuracy evaluation of a novel methodology.

    PubMed

    Marzaioli, Fabio; Lubritto, Carmine; Nonni, Sara; Passariello, Isabella; Capano, Manuela; Terrasi, Filippo

    2011-03-15

    Mortars represent a class of building and art materials that are widespread at archeological sites from the Neolithic period on. After about 50 years of experimentation, the possibility to evaluate their absolute chronology by means of radiocarbon ((14)C) remains still uncertain. With the use of a simplified mortar production process in the laboratory environment, this study shows the overall feasibility of a novel physical pretreatment for the isolation of the atmospheric (14)CO(2) (i.e., binder) signal absorbed by the mortars during their setting. This methodology is based on the assumption that an ultrasonic attack in liquid phase isolates a suspension of binder carbonates from bulk mortars. Isotopic ((13)C and (14)C), % C, X-ray diffractometry (XRD), and scanning electron microscopy (SEM) analyses were performed to characterize the proposed methodology. The applied protocol allows suppression of the fossil carbon (C) contamination originating from the incomplete burning of the limestone during the quick lime production, providing unbiased dating for "laboratory" mortars produced operating at historically adopted burning temperatures.

  7. A preliminary evaluation of the nonfuel mineral potential of Somalia

    USGS Publications Warehouse

    Greenwood, W.R.

    1982-01-01

    Additional exploration in Somalia is warranted for a wide variety of metallic and nonmetallic deposits. In Precambrian rocks, deposit types favorable for exploration include: a banded iron formation; platinum-bearing mafic-ultramafic complexes; tin-bearing quartz veins; phosphorite; stratabound base-metal deposits; uranium associated with Precambrian(?) syenite; apatite, molybdenum, and alumina in alkalic rocks; Jurassic and Cretaceous black shales; possible bedded-barite and massive base- and precious-metal sulfide deposits; vein barite in Tertiary rocks in fault zones; sepiolite and bentonite for drilling muds and other industrial uses; celestite; possible Tertiary zeolite; and uranium deposits. Several of these deposit types could be Jointly developed and integrated into domestic industries; for example, phosphate and gypsum, or bentonite for pelletized iron from the banded iron deposits. Other deposits such as barite and sepiolite are of value because of their proximity to major drilling operations in the Arabian Gulf. Still other deposits, such as alumina and banded iron, might be marketable because of proximity to aluminum and iron-refining industries now being constructed in Saudi Arabia. Some deposits, such as celestite, can be developed with little capital investment; others, such as the iron deposits, would require large capital commitments. Exploration and evaluation for many of these deposits can be accomplished by Somali geologists with a few advisors. Most of the deposits require feasibility studies conducted by teams of economic geologists, extractive metallurgists, and economists. Some marginal deposits could be exploited if cooperative development schemes could be negotiated with governments in nearby countries.

  8. Preliminary evaluation of the persistence of organic gunshot residue.

    PubMed

    Arndt, James; Bell, Suzanne; Crookshanks, Lindsey; Lovejoy, Marco; Oleska, Casey; Tulley, Tanya; Wolfe, Drew

    2012-10-10

    The organic components of gunshot residue (OGSR, also called firearms discharge residue (FDR) or cartridge discharge residue (CDR)) have been studied and discussed in the literature. These residues, consisting of particulates such as burned and unburned powder as well as molecular compounds, are rarely used in casework except for purposes such as shooting reconstructions. Molecular compounds that survive the firing event or that are created as a result of the firing event could, with focused research and development, open a new avenue for forensic gunshot residue analysis. In this study, the persistence of organic gunshot residue was evaluated using diphenylamine (DPA) as a target analyte and ion mobility spectrometry (IMS) as the detection system. Samples were collected from hands using a solvent swabbing technique and the swab was analyzed using direct thermal desorption for sample introduction into the IMS. OGSR was found to persist for at least 4 h. Although DPA is a widely used industrial compound, analysis of numerous blank and background samples (n∼100) did not show any significant response for DPA using this detector. Variations were noted among individuals and as such, the data set does not support estimation of a half-life as has been done for traditional primer residues. No secondary transfers were observed, suggesting the possibility of skin adhesion via interactions between the lipophilic organic compounds and skin lipids. IMS proved valuable as a means of generating patterns for forensic pattern matching and shows promise as a screening tool applied to firearms discharge.

  9. Naturally induced secondary radiation in interplanetary space: Preliminary analyses for gamma radiation and radioisotope production from thermal neutron activation

    NASA Astrophysics Data System (ADS)

    Plaza-Rosado, Heriberto

    1991-09-01

    Thermal neutron activation analyses were carried out for various space systems components to determine gamma radiation dose rates and food radiation contamination levels. The space systems components selected were those for which previous radiation studies existed. These include manned space vehicle radiation shielding, liquid hydrogen propellant tanks for a Mars mission, and a food supply used as space vehicle radiation shielding. The computational method used is based on the fast neutron distribution generated by the BRYNTRN and HZETRN transport codes for Galactic Cosmic Rays (GCR) at solar minimum conditions and intense solar flares in space systems components. The gamma dose rates for soft tissue are calculated for water and aluminum space vehicle slab shields considering volumetric source self-attenuation and exponential buildup factors. In the case of the lunar habitat with regolith shielding, a completely exposed spherical habitat was assumed for mathematical convenience and conservative calculations. Activation analysis of the food supply used as radiation shielding is presented for four selected nutrients: potassium, calcium, sodium, and phosphorus. Radioactive isotopes that could represent a health hazard if ingested are identified and their concentrations are identified. For nutrients soluble in water, it was found that all induced radioactivity was below the accepted maximum permissible concentrations.

  10. Naturally induced secondary radiation in interplanetary space: Preliminary analyses for gamma radiation and radioisotope production from thermal neutron activation

    NASA Technical Reports Server (NTRS)

    Plaza-Rosado, Heriberto

    1991-01-01

    Thermal neutron activation analyses were carried out for various space systems components to determine gamma radiation dose rates and food radiation contamination levels. The space systems components selected were those for which previous radiation studies existed. These include manned space vehicle radiation shielding, liquid hydrogen propellant tanks for a Mars mission, and a food supply used as space vehicle radiation shielding. The computational method used is based on the fast neutron distribution generated by the BRYNTRN and HZETRN transport codes for Galactic Cosmic Rays (GCR) at solar minimum conditions and intense solar flares in space systems components. The gamma dose rates for soft tissue are calculated for water and aluminum space vehicle slab shields considering volumetric source self-attenuation and exponential buildup factors. In the case of the lunar habitat with regolith shielding, a completely exposed spherical habitat was assumed for mathematical convenience and conservative calculations. Activation analysis of the food supply used as radiation shielding is presented for four selected nutrients: potassium, calcium, sodium, and phosphorus. Radioactive isotopes that could represent a health hazard if ingested are identified and their concentrations are identified. For nutrients soluble in water, it was found that all induced radioactivity was below the accepted maximum permissible concentrations.

  11. [Preliminary evaluation of Chile's First Citizen Consensus Conference].

    PubMed

    Pellegrini Filho, Alberto; Zurita, Laura

    2004-05-01

    This piece provides an initial assessment of the First Citizen Consensus Conference, an event held in the city of Santiago, Chile, from 22-24 November 2003, on the subject of "The Management of My Medical Record." This conference was the first citizen consensus conference that has been held in Chile as well as the first such conference in Latin America. Consensus conferences were devised by the Danish Board of Technology in 1987 as a way to assess science and technology issues through discussions between experts and a panel of lay persons. At the end of a consensus conference, the lay persons express their opinions and recommendations in a consensus report that is directed at policymakers, decision-makers, and the public in general. The objective of a consensus conference is to bridge the gaps that routinely exist among the general public, experts, and elected officials. So far, the Danish Board of Technology has organized more than 20 of these conferences, using a methodology that has become established as a model. Taking into account the changes that have occurred in the relationship between science and society at large, the Pan American Health Organization has decided to support the holding of consensus conferences in Latin America and the Caribbean. The First Citizen Consensus Conference adapted the Danish methodology to conditions in Chile, and this piece assesses the modifications that were made. In addition, some 6 to 12 months after the conference, there will be an external evaluation of the outcomes and impact of the conference, especially in the communications media, public debate, decision-making, and perceptions of the persons who were involved. Despite the criticisms made in this piece and some shortcomings that are pointed out, the First Citizen Consensus Conference achieved all of its objectives and will serve as an excellent model for similar conferences in other countries of the Americas.

  12. Evaluation of Damage Tolerance of Advanced SiC/SiC Composites after Neutron Irradiation

    NASA Astrophysics Data System (ADS)

    Ozawa, Kazumi; Katoh, Yutai; Nozawa, Takashi; Hinoki, Tatsuya; Snead, Lance L.

    2011-10-01

    Silicon carbide composites (SiC/SiC) are attractive candidate materials for structural and functional components in fusion energy systems. The effect of neutron irradiation on damage tolerance of the nuclear grade SiC/SiC composites (plain woven Hi-Nicalon™ Type-S reinforced CVI matrix composites multilayer interphase and unidirectional Tyranno™-SA3 reinforced NITE matrix with carbon mono-layer interphase) was evaluated by means of miniaturized single-edged notched beam test. No significant changes in crack extension behavior and in the load-loadpoint displacement characteristics such as the peak load and hysteresis loop width were observed after irradiation to 5.9 × 1025 n/m2 (E > 0.1 MeV) at 800°C and to 5.8 × 1025 n/m2 at 1300°C. By applying a global energy balance analysis based on non-linear fracture mechanics, the energy release rate for these composite materials was found to be unchanged by irradiation with a value of 3±2 kJ/m2. This has led to the conclusion that, for these fairly aggressive irradiation conditions, the effect of neutron irradiation on the fracture resistance of these composites appears insignificant.

  13. Neutronics Evaluation of Lithium-Based Ternary Alloys in IFE Blankets

    SciTech Connect

    Jolodosky, A.; Fratoni, M.

    2014-11-20

    Pre-conceptual fusion blanket designs require research and development to reflect important proposed changes in the design of essential systems, and the new challenges they impose on related fuel cycle systems. One attractive feature of using liquid lithium as the breeder and coolant is that it has very high tritium solubility and results in very low levels of tritium permeation throughout the facility infrastructure. However, lithium metal vigorously reacts with air and water and presents plant safety concerns. If the chemical reactivity of lithium could be overcome, the result would have a profound impact on fusion energy and associated safety basis. The overriding goal of this project is to develop a lithium-based alloy that maintains beneficial properties of lithium (e.g. high tritium breeding and solubility) while reducing overall flammability concerns. To minimize the number of alloy combinations that must be explored, only those alloys that meet certain nuclear performance metrics will be considered for subsequent thermodynamic study. The specific scope of this study is to evaluate the neutronics performance of lithium-based alloys in the blanket of an inertial confinement fusion (ICF) engine. The results of this study will inform the development of lithium alloys that would guarantee acceptable neutronics performance while mitigating the chemical reactivity issues of pure lithium.

  14. Neutron metrology laboratory facility simulation.

    PubMed

    Pereira, Mariana; Salgado, Ana P; Filho, Aidano S; Pereira, Walsan W; Patrão, Karla C S; Fonseca, Evaldo S

    2014-10-01

    The Neutron Low Scattering Laboratory in Brazil has been completely rebuilt. Evaluation of air attenuation parameters and neutron component scattering in the room was done using Monte Carlo simulation code. Neutron fields produced by referenced neutron source were used to calculate neutron scattering and air attenuation.

  15. Evaluation of neutron flux parameters in irradiation sites of research reactor using the Westcott-formalism for the k0 neutron activation analysis method

    NASA Astrophysics Data System (ADS)

    Kasban, H.; Hamid, Ashraf

    2015-12-01

    Instrumental Neutron Activation Analysis using k0 (k0-INAA) method has been used to determine a number of elements in sediment samples collected from El-Manzala Lake in Egypt. k0-INAA according to Westcott's formalism has been implemented using the complete irradiation kit of the fast pneumatic rabbit and some selected manually loaded irradiation sites for short and long irradiation at Egypt Second Research Reactor (ETRR-2). Zr-Au and Co sets as neutron flux monitors are used to determine the neutron flux parameters (f and α) in each irradiation sites. Two reference materials IAEA Soil-7 samples have been inserted and implemented for data validation and an internal monostandard multi monitor used (k0 based IM-NAA). It was given a good agreement between the experimental analyzed values and that obtained of the certified values. The major and trace elements in the sediment samples have been evaluated with the use of Co as an internal and Au as an external monostandard comparators. The concentrations of the elements (Cr, Mn and Zn) in the sediment samples of the present work are discussed regarding to those obtained from other sites.

  16. Evaluating the performance of two neutron spectrum unfolding codes based on iterative procedures and artificial neural networks

    NASA Astrophysics Data System (ADS)

    Ortiz-Rodríguez, J. M.; Reyes Alfaro, A.; Reyes Haro, A.; Solís Sánches, L. O.; Miranda, R. Castañeda; Cervantes Viramontes, J. M.; Vega-Carrillo, H. R.

    2013-07-01

    In this work the performance of two neutron spectrum unfolding codes based on iterative procedures and artificial neural networks is evaluated. The first one code based on traditional iterative procedures and called Neutron spectrometry and dosimetry from the Universidad Autonoma de Zacatecas (NSDUAZ) use the SPUNIT iterative algorithm and was designed to unfold neutron spectrum and calculate 15 dosimetric quantities and 7 IAEA survey meters. The main feature of this code is the automated selection of the initial guess spectrum trough a compendium of neutron spectrum compiled by the IAEA. The second one code known as Neutron spectrometry and dosimetry with artificial neural networks (NDSann) is a code designed using neural nets technology. The artificial intelligence approach of neural net does not solve mathematical equations. By using the knowledge stored at synaptic weights on a neural net properly trained, the code is capable to unfold neutron spectrum and to simultaneously calculate 15 dosimetric quantities, needing as entrance data, only the rate counts measured with a Bonner spheres system. Similarities of both NSDUAZ and NSDann codes are: they follow the same easy and intuitive user's philosophy and were designed in a graphical interface under the LabVIEW programming environment. Both codes unfold the neutron spectrum expressed in 60 energy bins, calculate 15 dosimetric quantities and generate a full report in HTML format. Differences of these codes are: NSDUAZ code was designed using classical iterative approaches and needs an initial guess spectrum in order to initiate the iterative procedure. In NSDUAZ, a programming routine was designed to calculate 7 IAEA instrument survey meters using the fluence-dose conversion coefficients. NSDann code use artificial neural networks for solving the ill-conditioned equation system of neutron spectrometry problem through synaptic weights of a properly trained neural network. Contrary to iterative procedures, in neural

  17. Evaluating the performance of two neutron spectrum unfolding codes based on iterative procedures and artificial neural networks

    SciTech Connect

    Ortiz-Rodriguez, J. M.; Reyes Alfaro, A.; Reyes Haro, A.; Solis Sanches, L. O.; Miranda, R. Castaneda; Cervantes Viramontes, J. M.; Vega-Carrillo, H. R.

    2013-07-03

    In this work the performance of two neutron spectrum unfolding codes based on iterative procedures and artificial neural networks is evaluated. The first one code based on traditional iterative procedures and called Neutron spectrometry and dosimetry from the Universidad Autonoma de Zacatecas (NSDUAZ) use the SPUNIT iterative algorithm and was designed to unfold neutron spectrum and calculate 15 dosimetric quantities and 7 IAEA survey meters. The main feature of this code is the automated selection of the initial guess spectrum trough a compendium of neutron spectrum compiled by the IAEA. The second one code known as Neutron spectrometry and dosimetry with artificial neural networks (NDSann) is a code designed using neural nets technology. The artificial intelligence approach of neural net does not solve mathematical equations. By using the knowledge stored at synaptic weights on a neural net properly trained, the code is capable to unfold neutron spectrum and to simultaneously calculate 15 dosimetric quantities, needing as entrance data, only the rate counts measured with a Bonner spheres system. Similarities of both NSDUAZ and NSDann codes are: they follow the same easy and intuitive user's philosophy and were designed in a graphical interface under the LabVIEW programming environment. Both codes unfold the neutron spectrum expressed in 60 energy bins, calculate 15 dosimetric quantities and generate a full report in HTML format. Differences of these codes are: NSDUAZ code was designed using classical iterative approaches and needs an initial guess spectrum in order to initiate the iterative procedure. In NSDUAZ, a programming routine was designed to calculate 7 IAEA instrument survey meters using the fluence-dose conversion coefficients. NSDann code use artificial neural networks for solving the ill-conditioned equation system of neutron spectrometry problem through synaptic weights of a properly trained neural network. Contrary to iterative procedures, in neural

  18. Benchmark Evaluation of the Neutron Radiography (NRAD) Reactor Upgraded LEU-Fueled Core

    SciTech Connect

    John D. Bess

    2001-09-01

    Benchmark models were developed to evaluate the cold-critical start-up measurements performed during the fresh core reload of the Neutron Radiography (NRAD) reactor with Low Enriched Uranium (LEU) fuel. The final upgraded core configuration with 64 fuel elements has been completed. Evaluated benchmark measurement data include criticality, control-rod worth measurements, shutdown margin, and excess reactivity. Dominant uncertainties in keff include the manganese content and impurities contained within the stainless steel cladding of the fuel and the 236U and erbium poison content in the fuel matrix. Calculations with MCNP5 and ENDF/B-VII.0 nuclear data are approximately 1.4% greater than the benchmark model eigenvalue, supporting contemporary research regarding errors in the cross section data necessary to simulate TRIGA-type reactors. Uncertainties in reactivity effects measurements are estimated to be ~10% with calculations in agreement with benchmark experiment values within 2s. The completed benchmark evaluation de-tails are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Experiments (IRPhEP Handbook). Evaluation of the NRAD LEU cores containing 56, 60, and 62 fuel elements have also been completed, including analysis of their respective reactivity effects measurements; they are also available in the IRPhEP Handbook but will not be included in this summary paper.

  19. Evaluation of an agro--ecosystem model using cosmicray neutron soil moisture

    NASA Astrophysics Data System (ADS)

    Carr, Benjamin David

    The properties of the land surface affect the interaction of the surface and the atmosphere. The partitioning of absorbed shortwave radiation into emitted radiation, sensible heat flux, latent heat flux, and soil heat flux is determined by the presence of soil moisture. When the land surface is dry, there will be higher sensible heat flux, emitted radiation and soil heat flux. However, when liquid water is present, latent energy will be used to change the phase of water from solid to liquid and liquid to gas. This latent heat flux moves water and energy to a different part of the atmosphere. A contributing factor to soil moisture available for latent heat flux is the water table. With a shallow water table (< 5 m), plant roots are able to extract water for growth and generally an increase in latent heat flux is seen. In the Midwest U.S., the management of fields changes the latent heat flux through different crop choices, planting and harvest date, fertilizer application, and tile drainage. Therefore, land surface models, like Agro--IBIS, need to be simulated and evaluated at the field--scale. Agro--IBIS is an agroecosystem model that is able to incorporate changes in vegetation growth as well as management practices, which in turn impact soil moisture available for latent heat flux. Agro--IBIS has been updated with the soil physics of HYDRUS--1D in order to accurately simulate the impact of the water table. In measuring soil moisture, a consistent challenge is the representative scale of the instrument, which is often a point. A newer method of obtaining soil moisture over the field--scale is using a cosmic--ray neutron detector, which is sensitive to a diameter of 700 m and to a depth of ˜ 20 cm. I used soil moisture observed by the cosmic--ray neutron detector in an agricultural field to evaluate estimates made with the Agro--IBIS model over a growing season of maize and a growing season of soybean. Because of the large area observed by the cosmic-ray neutron

  20. Preliminary Evaluation of the Korean Seismological Research Station Short-Period Array

    DTIC Science & Technology

    1975-07-29

    PREUMINARV (VAIUAVION OF THE KOREAN SEISMOlOCICAl RESEARCH STAIION SHORT PERIOO ARRAY TECHNICAL REPORT NO. S VELA NETWORK EVAIUAT10N AND AUTOMATIC... accomplished under the tech. nical direction of the Air Force Technical Applications Center under Contract No. F08606-7 5-(,-0029. FORMATION SERVICE...34 ALEX(01)-TR-75-05 PRELIMINARY EVALUATION OF THE KOREAN SEISMOLOGICAL RESEARCH STATION SHORT PERIOD ARRAY TECHNICAL REPORT NO. 5 VELA NETWORK

  1. User-centered evaluation of handle shape and size and input controls for a neutron detector.

    PubMed

    Herring, Scarlett R; Castillejos, Pamela; Hallbeck, M Susan

    2011-11-01

    Current neutron detectors are big, heavy, difficult to use and are not ergonomically designed. Good handle design and easy to use control mechanisms are imperative for comfort, usability and accuracy for hand-held tools. Two studies were performed to assess these factors; Study I explored handle design (shape and size) preference and Study II evaluated the effects of control mechanisms, device orientations and word orientation on performance time. According to research findings, the recommended handle perimeter is 11 cm with a diameter range of 3.5-4.0 cm. These results demonstrated that as the handle perimeter decreased the handle becomes less preferred by first responders when using layered gloves. For control type, the fastest performance time was found with vertical push buttons and a vertical word orientation. These objective results matched the subjective results, which showed that the most preferred controller was a vertical push button control.

  2. Field test and evaluation of the passive neutron coincidence collar for prototype fast reactor fuel subassemblies

    SciTech Connect

    Menlove, H.O.; Keddar, A.

    1982-08-01

    The passive neutron Coincidence Collar, which was developed for the verification of plutonium content in fast reactor fuel subassemblies, has been field tested using Prototype Fast Reactor fuel. For passive applications, the system measures the /sup 240/Pu-effective mass from the spontaneous fission rate, and in addition, a self-interrogation technique is used to determine the fissile content in the subassembly. Both the passive and active modes were evaluated at the Windscale Works in the United Kingdom. The results of the tests gave a standard deviation 0.75% for the passive count and 3 to 7% for the active measurement for a 1000-s counting time. The unit will be used in the future for the verification of plutonium in fresh fuel assemblies.

  3. Comparisons of Neutron Cross Sections and Isotopic Composition Calculations for Fission-Product Evaluations

    NASA Astrophysics Data System (ADS)

    Kim, Do Heon; Gil, Choong-Sup; Chang, Jonghwa; Lee, Yong-Deok

    2005-05-01

    The neutron absorption cross sections for 18 fission products evaluated within the framework of the KAERI (Korea Atomic Energy Research Institute)-BNL (Brookhaven National Laboratory) international collaboration have been compared with ENDF/B-VI.7. Also, the influence of the new evaluations on the isotopic composition calculations of the fission products has been estimated through the OECD/NEA burnup credit criticality benchmarks (Phase 1B) and the LWR/Pu recycling benchmarks. These calculations were performed by WIMSD-5B with the 69-group libraries prepared from three evaluated nuclear data libraries: ENDF/B-VI.7, ENDF/B-VI.8 including the new evaluations in the resonance region covering the thermal region, and the expected ENDF/B-VII including those in the upper resonance region up to 20 MeV. For Xe-131, the composition calculated with ENDF/B-VI.8 shows a maximum difference of 5.02% compared to ENDF/B-VI.7. However, the isotopic compositions of all the fission products calculated with the expected ENDF/B-VII show no differences when compared to ENDF/B-VI.7 for the thermal reactor benchmark cases.

  4. Evaluation of {sup 28,29,30}Si neutron induced cross sections for ENDF/B-VI

    SciTech Connect

    Hetrick, D.M.; Larson, D.C.; Larson, N.M.; Leal, L.C.; Epperson, S.J.

    1997-04-01

    Separate evaluations have been done for the three stable isotopes of silicon for ENDF/B-VI. The evaluations are based on analysis of experimental data, supplemented by results of nuclear model calculations. The computational methods and the parameters required as input to the nuclear model codes are reviewed. Discussion of the evaluated data given for resonance parameters, neutron induced reaction cross sections, associated angular and energy distributions, and gamma-ray production cross sections is included. Extensive comparisons of the evaluated cross sections to measured data are shown in this report. The evaluations include all necessary data to allow KERMA (Kinetic Energy Released in MAterials) and displacement cross sections to be calculated directly. These quantities are fundamental to studies of neutron heating and radiation damage.

  5. R-Matrix Evaluation of {sup 16}O neutron cross sections up to 6.3 MeV

    SciTech Connect

    Sayer, R.O.; Leal, L.C.; Larson, N.M.; Spencer, R.R.; and Wright, R.Q.

    2000-08-01

    In this paper the authors describe an evaluation of {sup 16}O neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Resonance analyses were performed with the computer code SAMMY [LA98] which utilizes Bayes' method, a generalized least squares technique.

  6. In-plant test and evaluation of the neutron collar for verification of PWR fuel assemblies at Resende, Brazil

    SciTech Connect

    Menlove, H.O.; Marzo, M.A.S.; de Almeida, S.G.; de Almeida, M.C.; Moitta, L.P.M.; Conti, L.F.; de Paiva, J.R.T.

    1985-11-01

    The neutron-coincidence collar has been evaluated for the measurement of pressurized-water reactor (PWR) fuel assemblies at the Fabrica de Elementos Combustiveis plant in Resende, Brazil. This evaluation was part of the cooperative-bilateral-safeguards technical-exchange program between the United States and Brazil. The neutron collar measures the STVU content per unit length of full fuel assemblies using neutron interrogation and coincidence counting. The STYU content is measured in the passive mode without the AmLi neutron-interrogation source. The extended evaluation took place over a period of 6 months with both scanning and single-zone measurements. The results of the tests gave a coincidence-response standard deviation of 0.7% (sigma = 1.49% for mass) for the active case and 2.5% for the passive case in 1000-s measurement times. The length measurement in the scanning mode was accurate to 0.77%. The accuracies of different calibration methods were evaluated and compared.

  7. Calculation of Maxwellian-averaged cross sections and their uncertainties using ENDF/B-VII.1 evaluated neutron library

    NASA Astrophysics Data System (ADS)

    Pritychenko, Boris

    2011-10-01

    Present contribution represents a first application of ENDF/B-VII.1 neutron library for calculation of Maxwellian-averaged cross sections and astrophysical reaction rates. Recent improvements in neutron cross section evaluations and more extensive utilization of covariance files, by the CSEWG collaboration, allowed us to perform complete calculations and provide additional insights on all currently available neutron-induced reaction data. Nuclear reaction calculations using ENDF libraries and current Java technologies will be discussed and new results will be presented. This work was sponsored by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy, under Contract No. DE-AC02-98CH10886 with Brookhaven Science Associates, LLC.

  8. Preliminary Assessment of the Nuclide Migration from the Activation Zone Around the Proposed Spallation Neutron Source Facility

    SciTech Connect

    Dole, L.R.

    1998-09-01

    The purpose of this study is to investigate the potential impacts of migrating radionuclides from the activation zone around the proposed Spallation Neutron Source (SNS). Using conservatively high estimates of the potential inventory of radioactive activation products that could form in the proposed compacted-soil shield berm around an SNS facility on the Oak Ridge Reservation (ORR), a conservative, simplified transport model was used to estimate the potential worst-case concentrations of the 12 long-lived isotopes in the groundwater under a site with the hydrologic characteristics of the ORR. Of the 12, only 3 isotopes showed any potential to exceed the U.S. Nuclear Regulatory Commission (NRC) 10 Code of Federal Regulations (CFR) Part 20 Drinking Water Limits (DWLs). These isotopes were 14C, 22Na, and 54Mn. The latter two activation products have very short half-lives of 2.6 years and 0.854 year, respectively. Therefore, these will decay before reaching an off-site receptor, and they cannot pose off-site hazards. However, for this extremely conservative model, which overestimates the mobility of the contaminant, 14C, which has a 5,730-year half-life, was shown to represent a potential concern in the context of this study's conservative assumptions. This study examines alternative modifications to the SNS shield berm and makes recommendations.

  9. Preliminary survey and evaluation of nonaquifer thermal energy storage concepts for seasonal storage

    SciTech Connect

    Blahnik, D.E.

    1980-11-01

    Thermal energy storage enables the capture and retention of heat energy (or cold) during one time period for use during another. Seasonal thermal energy storage (STES) involves a period of months between the input and recovery of energy. The purpose of this study was to make a preliminary investigation and evaluation of potential nonaquifer STES systems. Current literature was surveyed to determine the state of the art of thermal energy storage (TES) systems such as hot water pond storage, hot rock storage, cool ice storage, and other more sophisticated concepts which might have potential for future STES programs. The main energy sources for TES principally waste heat, and the main uses of the stored thermal energy, i.e., heating, cooling, and steam generation are described. This report reviews the development of sensible, latent, and thermochemical TES technologies, presents a preliminary evaluation of the TES methods most applicable to seasonal storage uses, outlines preliminary conclusions drawn from the review of current TES literature, and recommends further research based on these conclusions. A bibliography of the nonaquifer STES literature review, and examples of 53 different TES concepts drawn from the literature are provided. (LCL)

  10. Notification: Preliminary Research to Evaluate Proposed Superfund Sites on the U.S. EPA's National Priorities List

    EPA Pesticide Factsheets

    Project #OPE-FY13-0018, April 4, 2013. The Office of Inspector General plans to begin preliminary research to evaluate proposed Superfund sites on the U.S. Environmental Protection Agency’s National Priorities List.

  11. Preliminary evaluation of beta-spodumene as a fusion reactor structural material

    SciTech Connect

    Kelsey, P.V. Jr.; Schmunk, R.E.; Henslee, S.P.

    1981-01-01

    Beta-spodumene was investigated as a candidate material for use in fusion reactor environments. Properties which support the use of beta-spodumene include good thermal shock resistance, a very low coefficient of thermal expansion, a low-Z composition which would result in minimum impact on the plasma, and flexibility in fabrication processes. Specimens were irradiated in the Advanced Test Reactor (ATR) to a fluence of 5.3 x 10/sup 22/ n/m/sup 2/, E > 0.1 MeV, and 4.9 x 10/sup 23/ n/m/sup 2/ thermal fluence in order to obtain a preliminary evaluation of the impact of irradiation on the material. Preliminary data indicate that the mechanical properties of beta-spodumene are little affected by irradiation. Gas production and release have also been investigated.

  12. INITIAL EVALUATION OF A PULSED WHITE SPECTRUM NEUTRON GENERATOR FOR EXPLOSIVE DETECTION

    SciTech Connect

    King, Michael J.; Miller, Gill T.; Reijonen, Jani; Ji, Qing; Andresen, Nord; Gicquel,, Frederic; Kavlas, Taneli; Leung, Ka-Ngo; Kwan, Joe

    2008-06-02

    Successful explosive material detection in luggage and similar sized containers is acritical issue in securing the safety of all airline passengers. Tensor Technology Inc. has recently developed a methodology that will detect explosive compounds with pulsed fast neutron transmission spectroscopy. In this scheme, tritium beams will be used to generate neutrons with a broad energy spectrum as governed by the T(t,2n)4He fission reaction that produces 0-9 MeV neutrons. Lawrence Berkeley National Laboratory (LBNL), in collaboration with Tensor Technology Inc., has designedand fabricated a pulsed white-spectrum neutron source for this application. The specifications of the neutron source are demanding and stringent due to the requirements of high yield and fast pulsing neutron emission, and sealed tube, tritium operation. In a unique co-axial geometry, the ion source uses ten parallel rf induction antennas to externally couple power into a toroidal discharge chamber. There are 20 ion beam extraction slits and 3 concentric electrode rings to shape and accelerate the ion beam into a titanium cone target. Fast neutron pulses are created by using a set ofparallel-plate deflectors switching between +-1500 volts and deflecting the ion beams across a narrow slit. The generator is expected to achieve 5 ns neutron pulses at tritium ion beam energies between 80 - 120 kV. First experiments demonstrated ion source operation and successful beam pulsing.

  13. Preliminary geotechnical evaluation of deep borehole facilities for nuclear waste disposal in shales

    SciTech Connect

    Nataraj, M.S. New Orleans Univ., LA . Dept. of Civil Engineering)

    1991-01-01

    This study is concerned with a preliminary engineering evaluation of borehole facilities for nuclear waste disposal in shales. Some of the geotechnical properties of Pierre, Rhinestreet, and typical illite shale have been collected. The influence of a few geotechnical properties on strength and deformation of host material is briefly examined. It appears that Pierre shale is very unstable and requires support to prevent collapse. Typical illite shale is more stable than Rhinestreet shale, although it undergoes relatively more deformation. 16 refs., 5 figs., 3 tabs.

  14. Preliminary evaluation of the pretreatment of fuel alcohol fermentation stillage through an anaerobic filter

    SciTech Connect

    Jacquez, R.B.; Sales, A.; Wang, W.

    1982-11-01

    The objective of this research was to conduct a preliminary evaluation of the pretreatment of fuel alcohol fermentation stillage by means of an anaerobic filter. The first phase of the investigation was devoted to characterizing the stillage. The second phase of the investigation studied the reduction of suspended solids by centrifugation. In the third phase of the investigation laboratory scale anaerobic filters were tested as a means of pretreating the fermentation stillage. Overall, the anaerobic filter was demonstrated to be an effective means of pretreating fermentation stillage.

  15. Evaluation of the neutron background in an HPGe target for WIMP direct detection when using a reactor neutrino detector as a neutron veto system

    SciTech Connect

    Ji, Xiangpan; Xu, Ye Lin, Junsong; Feng, Yulong; Li, Haolin

    2013-11-15

    A direct WIMP (weakly interacting massive particle) detector with a neutron veto system is designed to better reject neutrons. The experimental configuration is studied in this paper involves 984 Ge modules placed inside a reactor-neutrino detector. The neutrino detector is used as a neutron veto device. The neutron background for the experimental design is estimated using the Geant4 simulation. The results show that the neutron background can decrease to O(0.01) events per year per tonne of high-purity germanium and it can be ignored in comparison with electron recoils.

  16. Experimental evaluation of boron neutron capture therapy of human breast carcinoma implanted on nude mice

    NASA Astrophysics Data System (ADS)

    Bose, Satya Ranjan

    2000-06-01

    An in-pool small animal irradiation neutron tube (SAINT) facility was designed, constructed and installed at the University of Virginia Nuclear Research Reactor (UVAR). Thermal neutron flux profiles were measured by foil activation analysis (gold) and verified with DORT and MCNP computer code models. The gamma-ray absorbed dose in the neutron-gamma mixed field was determined from TLD measurements. The SAINT thermal neutron flux was used to investigate the well characterized human breast cancer cell line MCF-7B on both in-vitro samples and in- vivo animal subjects. Boronophenylalanine (BPA enriched in 95% 10B) was used as a neutron capturing agent. The in-vitro response of MCF-7B human breast carcinoma cells to BPA in a mixed field of neutron-gamma radiation or pure 60Co gamma radiation was investigated. The best result (lowest surviving fraction) was observed in cell cultures pre-incubated with BPA and given the neutron irradiation. The least effective treatment consisted of 60Co irradiation only. Immunologically deficient nude mice were inoculated subcutaneously with human breast cancer MCF-7B cells and estradiol pellets (to support tumor growth). The tumor volume in the mouse control group increased over time, as expected. The group of mice exposed only to neutron treatment exhibited initial tumor volume reduction lasting until 35 days following the treatment, followed by renewed tumor growth. Both groups given BPA plus neutron treatment showed continuous reduction in tumor volume over the 55-day observation period. The group given the higher BPA concentration showed the best tumor reduction response. The results on both in-vitro and in-vivo studies showed increased cell killing with BPA, substantiating the incorporation of BPA into the tumor or cell line. Therefore, BNCT may be a possible choice for the treatment of human breast carcinoma. However, prior to the initiation of any clinical studies, it is necessary to determine the therapeutic efficacy in a large

  17. Towards an improved evaluation of neutron-induced fission cross sections on actinides

    NASA Astrophysics Data System (ADS)

    Goriely, S.; Hilaire, S.; Koning, A. J.; Capote, R.

    2011-03-01

    Mean-field calculations can now provide all the nuclear ingredients required to describe the fission path from the equilibrium deformation up to the nuclear scission point. The information obtained from microscopic mean-field models has been included in the TALYS reaction code to improve the predictions of neutron-induced fission cross sections. The nuclear inputs concern not only the details of the energy surface along the fission path, but also the coherent estimate of the nuclear level density derived within the combinatorial approach on the basis of the same single-particle properties, in particular at the fission saddle points. The predictive power of such a microscopic approach is tested on the experimental data available for the uranium isotopic chain. It is also shown that the various inputs can be tuned to reproduce, at best, experimental data in one unique coherent framework, so that in a close future it should become possible to make, on the basis of such models, accurate fission-cross-section calculations and the corresponding estimates for nuclei, energy ranges, or reaction channels for which no data exist. Such model uncertainties are usually not taken into account in data evaluations.

  18. Description and evaluation of nuclear masses based on residual proton-neutron interactions

    SciTech Connect

    Fu, G. J.; Lei, Y.; Jiang, H.; Zhao, Y. M.; Sun, B.; Arima, A.

    2011-09-15

    In this paper we study the residual proton-neutron interactions and make use of the systematics of these interactions to describe experimental data of nuclear masses and to predict some of the unknown masses. The odd-even effect staggering of the residual proton-neutron interaction between the last proton and the last neutron is found and argued in terms of pairing interactions. Two local mass relations, which work very accurately for masses of four neighboring nuclei, are discovered. The accuracy of our predicted masses for medium and heavy nuclei is competitive with that of the AME2003 extrapolations, with the virtue of simplicity.

  19. New technique to improve the accuracy of albedo neutron dosimeter evaluations

    NASA Astrophysics Data System (ADS)

    Hankins, D. E.

    The calibration factor for albedo neutron dosimeters varies greatly depending upon the energy of the neutrons in the exposure. Calibration results obtained over an eight-year period at each Lawrence Livermore National Laboratory facility where neutron exposure may occur were reviewed. A stronger relationship than expected was found between the ratio of the readings of the 9-in. to 3-in. spheres and the percent thermal. Readings from personnel and albedo badges were reviewed. The readings were consistent with the use of a calibration factor for the albedo dosimeter which varies with changes in the ratio of the personnel and albedo dosimeter TLD readings.

  20. Evaluation of neutron sources for ISAGE-in-situ-NAA for a future lunar mission.

    PubMed

    Li, X; Breitkreutz, H; Burfeindt, J; Bernhardt, H-G; Trieloff, M; Hopp, J; Jessberger, E K; Schwarz, W H; Hofmann, P; Hiesinger, H

    2011-11-01

    For a future Moon landing, a concept for an in-situ NAA involving age determination using the (40)Ar-(39)Ar method is developed. A neutron source (252)Cf is chosen for sample irradiation on the Moon. A special sample-in-source irradiation geometry is designed to provide a homogeneous distribution of neutron flux at the irradiation position. Using reflector, the neutron flux is likely to increase by almost 200%. Sample age of 1Ga could be determined. Elemental analysis using INAA is discussed.

  1. Collinear Cluster Tripartition as a Neutron Source--Evaluation of the Setup Parameters

    SciTech Connect

    Kamanin, D. V.; Kuznetsova, E. A.; Aleksandrov, A. A.; Aleksandrova, I. A.; Borzakov, S. B.; Chelnokov, M. L.; Pham Minh, D.; Kondratyev, N. A.; Kopach, Yu. N.; Panteleev, Ts.; Penionzhkevich, Yu. E.; Svirikhin, A. I.; Sokol, E. A.; Testov, D. A.; Zhuchko, V. E.; Yeremin, A. V.; Pyatkov, Yu. V.; Jacobs, N.; Ryabov, Yu. V.

    2010-04-30

    Forthcoming experiments aimed at studying the mechanism of collinear cluster tripartition are planning to be performed with the new facility. Charged products will be registered with the double arm time-of-flight spectrometer composed of mosaics of PIN -diodes and MCP (micro channel plates) based timing detectors. Several tens of {sup 3}He-filled counters will be gathered round the {sup 252}Cf source. In order to choose an optimal configuration of the neutron detector and other parameters of the experiment special modeling has performed using both 'neutron barrel' and known MCNP code. The first test run of the new facility is in progress also its 'neutron skin' in under construction.

  2. Neutron Cross Section Processing Methods for Improved Integral Benchmarking of Unresolved Resonance Region Evaluations

    NASA Astrophysics Data System (ADS)

    Walsh, Jonathan A.; Forget, Benoit; Smith, Kord S.; Brown, Forrest B.

    2016-03-01

    In this work we describe the development and application of computational methods for processing neutron cross section data in the unresolved resonance region (URR). These methods are integrated with a continuous-energy Monte Carlo neutron transport code, thereby enabling their use in high-fidelity analyses. Enhanced understanding of the effects of URR evaluation representations on calculated results is then obtained through utilization of the methods in Monte Carlo integral benchmark simulations of fast spectrum critical assemblies. First, we present a so-called on-the-fly (OTF) method for calculating and Doppler broadening URR cross sections. This method proceeds directly from ENDF-6 average unresolved resonance parameters and, thus, eliminates any need for a probability table generation pre-processing step in which tables are constructed at several energies for all desired temperatures. Significant memory reduction may be realized with the OTF method relative to a probability table treatment if many temperatures are needed. Next, we examine the effects of using a multi-level resonance formalism for resonance reconstruction in the URR. A comparison of results obtained by using the same stochastically-generated realization of resonance parameters in both the single-level Breit-Wigner (SLBW) and multi-level Breit-Wigner (MLBW) formalisms allows for the quantification of level-level interference effects on integrated tallies such as keff and energy group reaction rates. Though, as is well-known, cross section values at any given incident energy may differ significantly between single-level and multi-level formulations, the observed effects on integral results are minimal in this investigation. Finally, we demonstrate the calculation of true expected values, and the statistical spread of those values, through independent Monte Carlo simulations, each using an independent realization of URR cross section structure throughout. It is observed that both probability table

  3. Neutronics Evaluation of Lithium-Based Ternary Alloys in IFE Blankets

    SciTech Connect

    Jolodosky, A.; Fratoni, M.

    2015-09-22

    , low electrical conductivity and therefore low MHD pressure drop, low chemical reactivity, and extremely low tritium inventory; the addition of sodium (FLiNaBe) has been considered because it retains the properties of FliBe but also lowers the melting point. Although many of these blanket concepts are promising, challenges still remain. The limited amount of beryllium available poses a problem for ceramic breeders such as the HCPB. FLiBe and FLiNaBe are highly viscous and have a low thermal conductivity. Lithium lead possesses a poor thermal conductivity which can cause problems in both DCLL and LiPb blankets. Additionally, the tritium permeation from these two blankets into plant components can be a problem and must be reduced. Consequently, Lawrence Livermore National Laboratory (LLNL) is attempting to develop a lithium-based alloy—most likely a ternary alloy—which maintains the beneficial properties of lithium (e.g. high tritium breeding and solubility) while reducing overall flammability concerns for use in the blanket of an inertial fusion energy (IFE) power plant. The LLNL concept employs inertial confinement fusion (ICF) through the use of lasers aimed at an indirect-driven target composed of deuterium-tritium fuel. The fusion driver/target design implements the same physics currently experimented at the National Ignition Facility (NIF). The plant uses lithium in both the primary coolant and blanket; therefore, lithium-related hazards are of primary concern. Although reducing chemical reactivity is the primary motivation for the development of new lithium alloys, the successful candidates will have to guarantee acceptable performance in all their functions. The scope of this study is to evaluate the neutronics performance of a large number of lithium-based alloys in the blanket of the IFE engine and assess their properties upon activation. This manuscript is organized as follows: Section 12 presents the models and methodologies used for the analysis; Section

  4. PWR core design, neutronics evaluation and fuel cycle analysis for thorium-uranium breeding recycle

    SciTech Connect

    Bi, G.; Liu, C.; Si, S.

    2012-07-01

    This paper was focused on core design, neutronics evaluation and fuel cycle analysis for Thorium-Uranium Breeding Recycle in current PWRs, without any major change to the fuel lattice and the core internals, but substituting the UOX pellet with Thorium-based pellet. The fuel cycle analysis indicates that Thorium-Uranium Breeding Recycle is technically feasible in current PWRs. A 4-loop, 193-assembly PWR core utilizing 17 x 17 fuel assemblies (FAs) was taken as the model core. Two mixed cores were investigated respectively loaded with mixed reactor grade Plutonium-Thorium (PuThOX) FAs and mixed reactor grade {sup 233}U-Thorium (U{sub 3}ThOX) FAs on the basis of reference full Uranium oxide (UOX) equilibrium-cycle core. The UOX/PuThOX mixed core consists of 121 UOX FAs and 72 PuThOX FAs. The reactor grade {sup 233}U extracted from burnt PuThOX fuel was used to fabrication of U{sub 3}ThOX for starting Thorium-. Uranium breeding recycle. In UOX/U{sub 3}ThOX mixed core, the well designed U{sub 3}ThOX FAs with 1.94 w/o fissile uranium (mainly {sup 233}U) were located on the periphery of core as a blanket region. U{sub 3}ThOX FAs remained in-core for 6 cycles with the discharged burnup achieving 28 GWD/tHM. Compared with initially loading, the fissile material inventory in U{sub 3}ThOX fuel has increased by 7% via 1-year cooling after discharge. 157 UOX fuel assemblies were located in the inner of UOX/U{sub 3}ThOX mixed core refueling with 64 FAs at each cycle. The designed UOX/PuThOX and UOX/U{sub 3}ThOX mixed core satisfied related nuclear design criteria. The full core performance analyses have shown that mixed core with PuThOX loading has similar impacts as MOX on several neutronic characteristic parameters, such as reduced differential boron worth, higher critical boron concentration, more negative moderator temperature coefficient, reduced control rod worth, reduced shutdown margin, etc.; while mixed core with U{sub 3}ThOX loading on the periphery of core has no

  5. Preliminary Benchmark Evaluation of Japan’s High Temperature Engineering Test Reactor

    SciTech Connect

    John Darrell Bess

    2009-05-01

    A benchmark model of the initial fully-loaded start-up core critical of Japan’s High Temperature Engineering Test Reactor (HTTR) was developed to provide data in support of ongoing validation efforts of the Very High Temperature Reactor Program using publicly available resources. The HTTR is a 30 MWt test reactor utilizing graphite moderation, helium coolant, and prismatic TRISO fuel. The benchmark was modeled using MCNP5 with various neutron cross-section libraries. An uncertainty evaluation was performed by perturbing the benchmark model and comparing the resultant eigenvalues. The calculated eigenvalues are approximately 2-3% greater than expected with an uncertainty of ±0.70%. The primary sources of uncertainty are the impurities in the core and reflector graphite. The release of additional HTTR data could effectively reduce the benchmark model uncertainties and bias. Sensitivity of the results to the graphite impurity content might imply that further evaluation of the graphite content could significantly improve calculated results. Proper characterization of graphite for future Next Generation Nuclear Power reactor designs will improve computational modeling capabilities. Current benchmarking activities include evaluation of the annular HTTR cores and assessment of the remaining start-up core physics experiments, including reactivity effects, reactivity coefficient, and reaction-rate distribution measurements. Long term benchmarking goals might include analyses of the hot zero-power critical, rise-to-power tests, and other irradiation, safety, and technical evaluations performed with the HTTR.

  6. Synthesis and preliminary in vivo toxicity evaluation of an iodinated sulfidoborate

    SciTech Connect

    Miura, M.; Micca, P.L.; Heinrichs, J.C.; Slatkin, D.N.

    1992-12-31

    An iodine-labeled {sup 10}B-carrier would enable the biodistribution of {sup 10}B to be imaged noninvasively in patients so as to optimize the timing of neutron exposure for BNCT. While Na{sub 2}B{sub l2}H{sub 11}SH [BSH] is in clinical use for BNCT in Japan, its disulfido dimer Na{sub 4}B{sub 24}H{sub 22}S{sub 2} [BSSB] is also under consideration. We describe the synthesis of an iodinated product of the dimer for possible use in BNCT and compare its toxicity in normal mice to that of BSSB. Periodination of BSSB can be carried out under reaction conditions similar to those used for B{sub 12}H{sup 12}{sup {minus}2}. We surmise from this preliminary in vivo experiment that IBSSB may be slightly hepatotoxic to mice. Since the putative weight ratio of iodine to boron-10 in IBSSB is 11.5, the presence of a therapeutically adequate concentration of {sup 10}B in tumor, for example 30 {mu}g {sup 10}B per gram tumor, would be associated with 345 {mu}g I per gram tumor. This would be suitable for imaging a tumor in the brain and for quantifying the iodine using computed tomography [CT] without using conventional contrast enhancement. {sup 10}B concentrations useful for BNCT of malignant gliomas should be readily quantified by conventional CT using {sup 10}B-IBSSB as a combined radiographic contrast agent and {sup 10}B-carrier. Alternatively, iodine-radiolabeled IBSSB would allow visualization and quantification of iodine in the tumor by single photon emission computed tomography [SPECT]. Because boron and iodine are linked covalently in IBSSB, quantification of iodine in the tumor would thereby also quantify boron in the tumor noninvasively using either radiolabeled or nonradiolabeled IBSSB in SPECT or CT, respectively, provided that in vivo deiodination of IBSSB is sufficiently slow.

  7. Synthesis and preliminary in vivo toxicity evaluation of an iodinated sulfidoborate

    SciTech Connect

    Miura, M.; Micca, P.L.; Heinrichs, J.C.; Slatkin, D.N.

    1992-01-01

    An iodine-labeled [sup 10]B-carrier would enable the biodistribution of [sup 10]B to be imaged noninvasively in patients so as to optimize the timing of neutron exposure for BNCT. While Na[sub 2]B[sub l2]H[sub 11]SH [BSH] is in clinical use for BNCT in Japan, its disulfido dimer Na[sub 4]B[sub 24]H[sub 22]S[sub 2] [BSSB] is also under consideration. We describe the synthesis of an iodinated product of the dimer for possible use in BNCT and compare its toxicity in normal mice to that of BSSB. Periodination of BSSB can be carried out under reaction conditions similar to those used for B[sub 12]H[sup 12][sup [minus]2]. We surmise from this preliminary in vivo experiment that IBSSB may be slightly hepatotoxic to mice. Since the putative weight ratio of iodine to boron-10 in IBSSB is 11.5, the presence of a therapeutically adequate concentration of [sup 10]B in tumor, for example 30 [mu]g [sup 10]B per gram tumor, would be associated with 345 [mu]g I per gram tumor. This would be suitable for imaging a tumor in the brain and for quantifying the iodine using computed tomography [CT] without using conventional contrast enhancement. [sup 10]B concentrations useful for BNCT of malignant gliomas should be readily quantified by conventional CT using [sup 10]B-IBSSB as a combined radiographic contrast agent and [sup 10]B-carrier. Alternatively, iodine-radiolabeled IBSSB would allow visualization and quantification of iodine in the tumor by single photon emission computed tomography [SPECT]. Because boron and iodine are linked covalently in IBSSB, quantification of iodine in the tumor would thereby also quantify boron in the tumor noninvasively using either radiolabeled or nonradiolabeled IBSSB in SPECT or CT, respectively, provided that in vivo deiodination of IBSSB is sufficiently slow.

  8. A successful trial utilizing the Leuzinger-Bohleber methodology for evaluation of psychoanalytic treatment: preliminary report.

    PubMed

    Rascón, Socorro Ramonet; Corona, Pablo Cuevas; Lartigue, Teresa; Rios, Josefina Mendoza; Garza, David López

    2005-10-01

    Utilizing audio-recorded psychoanalytic interviews of both patients and their analysts, group discussions of these interviews, and the application of questionnaires commonly used in psychotherapy research, the authors investigate the potential use of the Leuzinger-Bohleber methodology as an objective evaluative instrument to assess the quality of psychoanalytic treatment. Preliminary study results were obtained through interviews conducted with seven analysts and their respective patients, three of whom were treated with psychoanalysis (three or more sessions per week, for a duration of no less than one year) and four with psychotherapy (one or two sessions per week, for a duration of no less than one year). Patients were found to be eager to participate, and no adverse experiences were reported by analysts, patients or the research team. In addition to the interviews, further data were obtained through review of mailed-in questionnaires completed by 21 patients. The authors present both preliminary observations regarding the methodology as a whole, as well as the detailed results of one specific case subject treated with psychotherapy. Review of study findings supports the utilization of this methodology as an evaluative instrument which may ultimately advance current knowledge of the process and outcome of psychoanalytic treatment.

  9. Preliminary study on quality evaluation of pecans with terahertz time-domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Bin; Cao, Wei; Mathanker, Sunil; Zhang, Weili; Wang, Ning

    2010-11-01

    This paper reports a preliminary work on a feasibility study of applying terahertz (THz) technology for pecan quality evaluation. A set of native pecan nuts collected in 2009 were used during the experiment. Each pecan nutmeat was manually sliced at a thickness of about 1mm, 2mm, and 3mm and a size of about 2cm (length) ×1cm (width). Pecan shell and inner separator were also cut into the same size. The absorption spectra for the nutmeat slices, shell, and inner separator were collected using a THz time-domain spectroscopy (THz-TDS) developed by a group of researchers at Oklahoma State University. The test results show that nutmeat, shell, and inner separator had different absorption characteristics within the bandwidth of 0.2-2.0 THz. To study the capability of insect damage detection of the THz spectroscopy, the absorption spectra of insects (living manduca sexta and dry pecan weevil) were also collected. Due to high water contents in the insects, very obvious spectral characteristics were found. The results from the preliminary study show a potential of THz technology applied for quality detection of bio-products. However, since bio-products mostly have high water content and are handled under an environment with certain levels of water content, practical issues needs to be further investigated to make the THz technology a feasible tool for quality evaluation.

  10. Preliminary Content Evaluation of the North Anna High Burn-Up Sister Fuel Rod Segments for Transportation in the 10-160B and NAC-LWT

    SciTech Connect

    Ketusky, E.

    2016-08-09

    The U.S. Department of Energy’s (DOE’s) Used Fuel Disposition Campaign (UFDC) Program has transported high-burnup nuclear sister fuel rods from a commercial nuclear power plant for purposes of evaluation and testing. The evaluation and testing of high-burnup used nuclear fuel is integral to DOE initiatives to collect information useful in determining the integrity of fuel cladding for future safe transportation of the fuel, and for determining the effects of aging, on the integrity of UNF subjected to extended storage and subsequent transportation. The UFDC Program, in collaboration with the U.S. Nuclear Regulatory Commission and the commercial nuclear industry, has obtained individual used nuclear fuel rods for testing. The rods have been received at Oak Ridge National Laboratory (ORNL) for both separate effects testing (SET) and small-scale testing (SST). To meet the research objectives, testing on multiple 6 inch fuel rod pins cut from the rods at ORNL will be performed at Pacific Northwest National Laboratory (PNNL). Up to 10 rod equivalents will be shipped. Options were evaluated for multiple shipments using the 10-160B (based on 4.5 rod equivalents) and a single shipment using the NAC-LWT. Based on the original INL/Virginia Power transfer agreement, the rods are assumed to 152 inches in length with a 0.374-inch diameter. This report provides a preliminary content evaluation for use of the 10-160B and NAC-LWT for transporting those fuel rod pins from ORNL to PNNL. This report documents the acceptability of using these packagings to transport the fuel segments from ORNL to PNNL based on the following evaluations: enrichment, A2 evaluation, Pu-239 FGE evaluation, heat load, shielding (both gamma and neutron), and content weight/structural evaluation.

  11. Evaluation of kalman filters and genetic algorithms for delayed neutron nondestructive assay data analyses.

    SciTech Connect

    Aumeier, S. E.; Forsmann, J. H.; Engineering Division

    1998-04-01

    The ability to nondestructively determine the presence and quantity of fissile/fertile nuclei in various matrices is important in several areas of nuclear applications, including international and domestic safeguards, radioactive waste characterization, and nuclear facility operations. An analysis was performed to determine the feasibility of identifying the masses of individual fissionable isotopes from a cumulative delayed-neutron signal resulting from the neutron irradiation of several uranium and plutonium isotopes. The feasibility of two separate data-processing techniques was studied: Kalman filtering and genetic algorithms. The basis of each technique is reviewed, and the structure of the algorithms as applied to the delayed-neutron analysis problem is presented. The results of parametric studies performed using several variants of the algorithms are presented. The effect of including additional constraining information such as additional measurements and known relative isotopic concentration is discussed. The parametric studies were conducted using simulated delayed-neutron data representative of the cumulative delayed-neutron response following irradiation of a sample containing {sup 238}U, {sup 235}U, {sup 239}Pu, and {sup 240}Pu. The results show that by processing delayed-neutron data representative of two significantly different fissile/fertile fission ratios, both Kalman filters and genetic algorithms are capable of yielding reasonably accurate estimates of the mass of individual isotopes contained in a given assay sample.

  12. Evaluation of Kalman filters and genetic algorithms for delayed-neutron nondestructive assay data analyses

    SciTech Connect

    Aumeier, S.E.; Forsmann, J.H.

    1998-04-01

    The ability to nondestructively determine the presence and quantity of fissile/fertile nuclei in various matrices is important in several areas of nuclear applications, including international and domestic safeguards, radioactive waste characterization, and nuclear facility operations. An analysis was performed to determine the feasibility of identifying the masses of individual fissionable isotopes from a cumulative delayed-neutron signal resulting form the neutron irradiation of several uranium and plutonium isotopes. The feasibility of two separate data-processing techniques was studied: Kalman filtering and genetic algorithms. The basis of each technique is reviewed, and the structure of the algorithms as applied to the delayed-neutron analysis problem is presented. The results of parametric studies performed using several variants of the algorithms are presented. The effect of including additional constraining information such as additional measurements and known relative isotopic concentration is discussed. The parametric studies were conducted using simulated delayed-neutron data representative of the cumulative delayed-neutron response following irradiation of a sample containing {sup 238}U, {sup 235}U, {sup 239}Pu, and {sup 240}Pu. The results show that by processing delayed-neutron data representative of two significantly different fissile/fertile fission ratios, both Kalman filters and genetic algorithms are capable of yielding reasonably accurate estimates of the mass of individual isotopes contained in a given assay sample.

  13. Development of the wireless ultra-miniaturized inertial measurement unit WB-4: preliminary performance evaluation.

    PubMed

    Lin, Zhuohua; Zecca, Massimiliano; Sessa, Salvatore; Bartolomeo, Luca; Ishii, Hiroyuki; Takanishi, Atsuo

    2011-01-01

    This paper presents the preliminary performance evaluation of our new wireless ultra-miniaturized inertial measurement unit (IMU) WB-4 by compared with the Vicon motion capture system. The WB-4 IMU primarily contains a mother board for motion sensing, a Bluetooth module for wireless data transmission with PC, and a Li-Polymer battery for power supply. The mother board is provided with a microcontroller and 9-axis inertial sensors (miniaturized MEMS accelerometer, gyroscope and magnetometer) to measure orientation. A quaternion-based extended Kalman filter (EKF) integrated with an R-Adaptive algorithm for automatic estimation of the measurement covariance matrix is implemented for the sensor fusion to retrieve the attitude. The experimental results showed that the wireless ultra-miniaturized WB-4 IMU could provide high accuracy performance at the angles of roll and pitch. The yaw angle which has reasonable performance needs to be further evaluated.

  14. Preliminary safety evaluation (PSE) for Sodium Storage Facility at the Fast Flux Test Facility

    SciTech Connect

    Bowman, B.R.

    1994-09-30

    This evaluation was performed for the Sodium Storage Facility (SSF) which will be constructed at the Fast Flux Test Facility (FFTF) in the area adjacent to the South and West Dump Heat Exchanger (DHX) pits. The purpose of the facility is to allow unloading the sodium from the FFTF plant tanks and piping. The significant conclusion of this Preliminary Safety Evaluation (PSE) is that the only Safety Class 2 components are the four sodium storage tanks and their foundations. The building, because of its imminent risk to the tanks under an earthquake or high winds, will be Safety Class 3/2, which means the building has a Safety Class 3 function with the Safety Class 2 loads of seismic and wind factored into the design.

  15. Evaluation of the cosmic-ray neutron method for measuring integral soil moisture dynamics of a forested head water catchment

    NASA Astrophysics Data System (ADS)

    Bogena, H. R.; Metzen, D.; Baatz, R.; Hendricks Franssen, H.; Huisman, J. A.; Montzka, C.; Vereecken, H.

    2011-12-01

    Measurements of low-energy secondary neutron intensity above the soil surface by cosmic-ray soil moisture probes (CRP) can be used to estimate soil moisture content. CRPs utilise the fact that high-energy neutrons initiated by cosmic rays are moderated (slowed to lower energies) most effectively by collisions with hydrogen atoms contained in water molecules in the soil. The conversion of neutron intensity to soil moisture content can potentially be complicated because neutrons are also moderated by aboveground water storage (e.g. vegetation water content, canopy storage of interception). Recently, it was demonstrated experimentally that soil moisture content derived from CRP measurements agrees well with average moisture content from gravimetric soil samples taken within the footprint of the cosmic ray probe, which is proposed to be up to several hundred meters in size [1]. However, the exact extension and shape of the CRP integration footprint is still an open question and it is also unclear how CRP measurements are affected by the soil moisture distribution within the footprint both in horizontal and vertical directions. In this paper, we will take advantage of an extensive wireless soil moisture sensor network covering most of the estimated footprint of the CRP. The network consists of 150 nodes and 900 soil moisture sensors which were installed in the small forested Wüstebach catchment (~27 ha) in the framework of the Transregio32 and the Helmholtz initiative TERENO (Terrestrial Environmental Observatories) [2]. This unique soil moisture data set provides a consistent picture of the hydrological status of the catchment in a high spatial and temporal resolution and thus the opportunity to evaluate the CRP measurements in a rigorous way. We will present first results of the comparison with a specific focus on the sensitivity of the CRP measurements to soil moisture variation in both the horizontal and vertical direction. Furthermore, the influence of forest

  16. R-Matrix Evaluation of 16O Neutron Cross Sections up to 6.3 MeV

    SciTech Connect

    Sayer, R.O.

    2000-08-21

    In this paper we describe an evaluation of {sup 16}O neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Resonance analyses were performed with the computer code SAMMY [LA98] which utilizes Bayes method, a generalized least squares technique. Over the years the nuclear community has developed a collection of evaluated nuclear data for applications in thermal, fast reactor, and fusion systems. However, typical neutron spectra in criticality safety applications are different from the spectra relevant to thermal, fast reactor, and fusion systems. In fact, the neutron spectra important for these non-reactor systems appear to peak in the epithermal energy range. Nuclear data play a major role in the calculation of the criticality safety margins for these systems. A thorough examination of how the present collection of nuclear data evaluations behaves in criticality safety calculations is needed. Many older evaluations will probably need to be revised, and new evaluations will be needed. Oxygen is an important element in criticality safety applications where oxides are present in significant abundance. The existing ENDF/B-VI.5 evaluation is expressed in terms of point-wise cross sections derived from the analysis of G. Hale [HA91]. Unfortunately such an evaluation is not directly useful for resonance analysis of data from samples in which oxygen is combined with other elements; for that purpose, Reich-Moore resonance parameters are needed. This paper addresses the task of providing those parameters. In the following sections we discuss the data, resonance analysis procedure, and results.

  17. RE-EVALUATION OF THE NEUTRON EMISSION FROM THE SOLAR FLARE OF 2005 SEPTEMBER 7, DETECTED BY THE SOLAR NEUTRON TELESCOPE AT SIERRA NEGRA

    SciTech Connect

    González, L. X.; Valdés-Galicia, J. F.; Musalem, O.; Hurtado, A.; Sánchez, F.; Muraki, Y.; Sako, T.; Matsubara, Y.; Nagai, Y.; Watanabe, K.; Shibata, S.; Sakai, T.

    2015-12-01

    The X17.0 solar flare of 2005 September 7 released high-energy neutrons that were detected by the Solar Neutron Telescope (SNT) at Sierra Negra, Mexico. In three separate and independent studies of this solar neutron event, several of its unique characteristics were studied; in particular, a power-law energy spectra was estimated. In this paper, we present an alternative analysis, based on improved numerical simulations of the detector using GEANT4, and a different technique for processing the SNT data. The results indicate that the spectral index that best fits the neutron flux is around 3, in agreement with previous works. Based on the numerically calculated neutron energy deposition on the SNT, we confirm that the detected neutrons might have reached an energy of 1 GeV, which implies that 10 GeV protons were probably produced; these could not be observed at Earth, as their parent flare was an east limb event.

  18. Preliminary Evaluation of Alternate Designs for HFIR Low-Enriched Uranium Fuel

    SciTech Connect

    Renfro, David; Chandler, David; Cook, David; Ilas, Germina; Jain, Prashant; Valentine, Jennifer

    2014-10-30

    Engineering design studies of the feasibility of conversion of the High Flux Isotope Reactor (HFIR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel are ongoing at Oak Ridge National Laboratory (ORNL) as part of an effort sponsored by the U.S. Department of Energy’s Global Threat Reduction Initiative (GTRI)/Reduced Enrichment for Research and Test Reactors (RERTR) program. The fuel type selected by the program for the conversion of the five high-power research reactors in the U.S. that still use HEU fuel is a new U-Mo monolithic fuel. Studies by ORNL have previously indicated that HFIR can be successfully converted using the new fuel provided (1) the reactor power can be increased from 85 MW to 100 MW and (2) the fuel can be fabricated to a specific reference design. Fabrication techniques for the new fuel are under development by the program but are still immature, especially for the “complex” aspects of the HFIR fuel design. In FY 2012, the program underwent a major shift in focus to emphasize developing and qualifying processes for the fabrication of reliable and affordable LEU fuel. In support of this new focus and in an effort to ensure that the HFIR fuel design is as suitable for reliable fabrication as possible, ORNL undertook the present study to propose and evaluate several alternative design features. These features include (1) eliminating the fuel zone axial contouring in the previous reference design by substituting a permanent neutron absorber in the lower unfueled region of all of the fuel plates, (2) relocating the burnable neutron absorber from the fuel plates of the inner fuel element to the side plates of the inner fuel element (the fuel plates of the outer fuel element do not contain a burnable absorber), (3) relocating the fuel zone inside the fuel plate to be centered on the centerline of the depth of the plate, and (4) reshaping the radial contour of the relocated fuel zone to be symmetric about this centerline. The

  19. Preliminary Evaluation of Alternate Designs for HFIR Low-Enriched Uranium Fuel

    SciTech Connect

    Renfro, David G; Chandler, David; Cook, David Howard; Ilas, Germina; Jain, Prashant K; Valentine, Jennifer R

    2014-11-01

    Engineering design studies of the feasibility of conversion of the High Flux Isotope Reactor (HFIR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel are ongoing at Oak Ridge National Laboratory (ORNL) as part of an effort sponsored by the U.S. Department of Energy s Global Threat Reduction Initiative (GTRI)/Reduced Enrichment for Research and Test Reactors (RERTR) program. The fuel type selected by the program for the conversion of the five high-power research reactors in the U.S. that still use HEU fuel is a new U-Mo monolithic fuel. Studies by ORNL have previously indicated that HFIR can be successfully converted using the new fuel provided (1) the reactor power can be increased from 85 MW to 100 MW and (2) the fuel can be fabricated to a specific reference design. Fabrication techniques for the new fuel are under development by the program but are still immature, especially for the complex aspects of the HFIR fuel design. In FY 2012, the program underwent a major shift in focus to emphasize developing and qualifying processes for the fabrication of reliable and affordable LEU fuel. In support of this new focus and in an effort to ensure that the HFIR fuel design is as suitable for reliable fabrication as possible, ORNL undertook the present study to propose and evaluate several alternative design features. These features include (1) eliminating the fuel zone axial contouring in the previous reference design by substituting a permanent neutron absorber in the lower unfueled region of all of the fuel plates, (2) relocating the burnable neutron absorber from the fuel plates of the inner fuel element to the side plates of the inner fuel element (the fuel plates of the outer fuel element do not contain a burnable absorber), (3) relocating the fuel zone inside the fuel plate to be centered on the centerline of the depth of the plate, and (4) reshaping the radial contour of the relocated fuel zone to be symmetric about this centerline. The present

  20. Evaluating outcomes of palliative photodynamic therapy: instrument development and preliminary results

    NASA Astrophysics Data System (ADS)

    Goodell, Teresa T.; Bargo, Paulo R.; Jacques, Steven L.

    2002-06-01

    Background: Subjective measures are considered the gold standard in palliative care evaluation, but no studies have evaluated palliative photodynamic therapy (PDT) subjectively. If PDT is to be accepted as a palliative therapy for later-stage obstructing esophageal and lung cancer, evidence of its effectiveness and acceptability to patients must be made known. Study Design/Materials and Methods: This ongoing study's major aim is to evaluate subjective outcomes of PDT in patients with obstructing esophageal and lung cancer. Existing measures of health status, dysphagia and performance status were supplemented with an instrument developed to evaluate PDT symptom relief and side effect burden, the PDT Side Effects Survey (PSES). Results: PDT patients treated with porfimer sodium (Photofrin) and 630-nm light experienced reduced dysphagia grade and stable performance status for at least one month after PDT (N= 10-17), but these effects did not necessarily persist at three months. Fatigue, appetite and quality of life may be the most burdensome issues for these patients. Conclusions: Preliminary data suggest that the PSES is an acceptable and valid tool for measuring subjective outcomes of palliative PDT. This study is the first attempt to systematically evaluate subjective outcomes of palliative PDT. Multi-center outcomes research is needed to draw generalizable conclusions that will establish PDT's effectiveness in actual clinical practice and enhance the wider adoption of PDT as a cancer symptom relief modality.

  1. Preliminary evaluation of alternative waste form solidification processes. Volume II. Evaluation of the processes

    SciTech Connect

    Not Available

    1980-08-01

    This Volume II presents engineering feasibility evaluations of the eleven processes for solidification of nuclear high-level liquid wastes (HHLW) described in Volume I of this report. Each evaluation was based in a systematic assessment of the process in respect to six principal evaluation criteria: complexity of process; state of development; safety; process requirements; development work required; and facility requirements. The principal criteria were further subdivided into a total of 22 subcriteria, each of which was assigned a weight. Each process was then assigned a figure of merit, on a scale of 1 to 10, for each of the subcriteria. A total rating was obtained for each process by summing the products of the subcriteria ratings and the subcriteria weights. The evaluations were based on the process descriptions presented in Volume I of this report, supplemented by information obtained from the literature, including publications by the originators of the various processes. Waste form properties were, in general, not evaluated. This document describes the approach which was taken, the developent and application of the rating criteria and subcriteria, and the evaluation results. A series of appendices set forth summary descriptions of the processes and the ratings, together with the complete numerical ratings assigned; two appendices present further technical details on the rating process.

  2. 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.

  3. Pilot Implementation and Preliminary Evaluation of START:AV Assessments in Secure Juvenile Correctional Facilities.

    PubMed

    Desmarais, Sarah L; Sellers, Brian G; Viljoen, Jodi L; Cruise, Keith R; Nicholls, Tonia L; Dvoskin, Joel A

    2012-01-01

    The Short-Term Assessment of Risk and Treatability: Adolescent Version (START:AV) is a new structured professional judgment guide for assessing short-term risks in adolescents. The scheme may be distinguished from other youth risk assessment and treatment planning instruments by its inclusion of 23 dynamic factors that are each rated for both vulnerability and strength. In addition, START:AV is also unique in that it focuses on multiple adverse outcomes-namely, violence, self-harm, suicide, unauthorized leave, substance abuse, self-neglect, victimization, and general offending-over the short-term (i.e., weeks to months) rather than long-term (i.e., years). This paper describes a pilot implementation and preliminary evaluation of START:AV in three secure juvenile correctional facilities in the southern United States. Specifically, we examined the descriptive characteristics and psychometric properties of START:AV assessments completed by 21 case managers on 291 adolescent offenders (250 boys and 41 girls) at the time of admission. Results provide preliminary support for the feasibility of completing START:AV assessments as part of routine practice. Findings also highlight differences in the characteristics of START:AV assessments for boys and girls and differential associations between the eight START:AV risk domains. Though results are promising, further research is needed to establish the reliability and validity of START:AV assessments completed in the field.

  4. A Preliminary Evaluation of Fast ForWord-Language as an Adjuvant Treatment in Language Intervention

    PubMed Central

    Fey, Marc E.; Finestack, Lizbeth H.; Gajewski, Byron J.; Popescu, Mihai; Lewine, Jeffrey D.

    2010-01-01

    Purpose Fast ForWord-Language (FFW-L) is designed to enhance children's processing of auditory–verbal signals and, thus, their ability to learn language. As a preliminary evaluation of this claim, we examined the effects of a 5-week course of FFW-L as an adjuvant treatment with a subsequent 5-week conventional narrative-based language intervention (NBLI) that targeted narrative comprehension and production and grammatical output. Method Twenty-three children 6–8 years of age with language impairments were assigned randomly to 1 of 3 intervention sequences: (a) FFW-L/NBLI, (b) NBLI/FFW-L, or (c) wait/NBLI. We predicted that after both treatment periods, the FFW-L/NBLI group would show greater gains on measures of narrative ability, conversational grammar, and nonword repetition than the other groups. Results After the first 5-week study period, the intervention groups, taken together (i.e., FFW-L/NBLI and NBLI/FFW-L), significantly outperformed the no-treatment wait/NBLI group on 2 narrative measures. At the final test period, all 3 groups displayed significant time-related effects on measures of narrative ability, but there were no statistically significant between-groups effects of intervention sequence. Conclusions This preliminary study provides no evidence to support the claim that FFW-L enhances children's response to a conventional language intervention. PMID:19696435

  5. Nubac Disc Arthroplasty: Preclinical Studies and Preliminary Safety and Efficacy Evaluations

    PubMed Central

    Songer, Matthew; Pimenta, Luis; Werner, Dieter; Reyes-Sanchez, Alejandro; Balsano, Massimo; Agrillo, Umberto; Coric, Domagoj; Davenport, Kenneth; Yuan, Hansen

    2007-01-01

    Background Disc arthroplasty is gaining popularity for treatment of low-back pain caused by degenerative disc disease (DDD). It can involve total disc replacement or partial disc or nucleus replacement (or augmentation). Compared with total disc replacement, nucleus replacement is less invasive, has less surgical risk, has faster postoperative recovery, and doesn't “burn bridges” should further surgery be required. However, nucleus replacement has a high risk of implant expulsion because the device is not fixed to the vertebrae. Nubac is the first polyetheretherketone (PEEK)-on-PEEK articulated disc arthroplasty device designed to optimally restore the lumbar anatomy and biomechanics. Methods ISO 10993 standards were used to evaluate the biocompatibility of the PEEK material. Chemical and thermal–mechanical tests and in vivo study assessed PEEK's biostability after exposure to high g irradiation and harsh oxidative conditions. Biomechanical tests to evaluate kinematic properties and anatomical restoration of the implanted lumbar motion segments and implant expulsion risk assessments were performed with a human cadaveric model. Because of the novelty of PEEK-on-PEEK as a self-mating articulating material, extensive wear tests were conducted with unidirectional and coupled motions. Static and fatigue strength also were tested. Animal study with a baboon model was conducted with gross, radiographic, biomechanical, and histological evaluations at 6 and 12 months postoperatively. Preliminary clinical data were collected through a prospective multicenter cohort study. Results PEEK demonstrated exceptional biocompatibility and biodurability. Nubac restored disc height and motion segment range of motion. The unique articulating design of the Nubac demonstrated low risk of implant expulsion in a human cadaveric model. Wear tests showed that the Nubac has minimal wear and compares favorably to other disc arthroplasty materials. The Nubac also had excellent static and

  6. Gravitational waves from rotating neutron stars and evaluation of fast chirp transform techniques

    NASA Astrophysics Data System (ADS)

    Strohmayer, Tod E.

    2002-04-01

    X-ray observations suggest that neutron stars in low mass x-ray binaries (LMXB) are rotating with frequencies in the range 300-600 Hz. These spin rates are significantly less than the break-up rates for essentially all realistic neutron star equations of state, suggesting that some process may limit the spin frequencies of accreting neutron stars to this range. If the accretion-induced spin up torque is in equilibrium with gravitational radiation losses, these objects could be interesting sources of gravitational waves. I present a brief summary of current measurements of neutron star spins in LMXBs based on the observations of high-Q oscillations during thermonuclear bursts (so-called 'burst oscillations'). Further measurements of neutron star spins will be important in exploring the gravitational radiation hypothesis in more detail. To this end, I also present a study of fast chirp transform (FCT) techniques as described by Jenet and Prince (Prince T A and Jenet F A 2000 Phys. Rev. D 62 122001) in the context of searching for the chirping signals observed during x-ray bursts.

  7. Evaluation of ZnS-family phosphors for neutron detectors using photon counting method

    NASA Astrophysics Data System (ADS)

    Kubota, N.; Katagiri, M.; Kamijo, K.; Nanto, H.

    2004-08-01

    A neutron detection sheet composed of ZnS:Ag as phosphor and 6LiF as neutron converter has been conventionally used for neutron detectors including imaging detectors because of its larger luminescence rate for α ray and shorter lifetime. However, the week point of ZnS:Ag phosphor is the slow component of the lifetime. Thus, we began to investigate other ZnS-family phosphors without the slow component of lifetime for neutron detectors using the photon counting method which needs a smaller number of photons of one order of magnitude. In this study, ZnO:Zn, ZnO:Ga, ZnSSe:Ag phosphor ceramics without the slow component of lifetime has been tried to fabricate using an electric furnace or a Spark Plasma Sintering (SPS) apparatus to appropriate for neutron detectors under high counting rates. The ZnO:Zn fabricated by means of the SPS method had the fastest lifetime of 4 ns though its detection efficiency was to be one-eighths as compared with a standard ZnS:Ag/ 6LiF detection sheet.

  8. Gravitational Waves from Rotating Neutron Stars and Evaluation of fast Chirp Transform Techniques

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod E.; White, Nicholas E. (Technical Monitor)

    2000-01-01

    X-ray observations suggest that neutron stars in low mass X-ray binaries (LMXB) are rotating with frequencies from 300 - 600 Hz. These spin rates are significantly less than the break-up rates for essentially all realistic neutron star equations of state, suggesting that some process may limit the spin frequencies of accreting neutron stars to this range. If the accretion induced spin up torque is in equilibrium with gravitational radiation losses, these objects could be interesting sources of gravitational waves. I present a brief summary of current measurements of neutron star spins in LMXBs based on the observations of high-Q oscillations during thermonuclear bursts (so called 'burst oscillations'). Further measurements of neutron star spins will be important in exploring the gravitational radiation hypothesis in more detail. To this end I also present a study of fast chirp transform (FCT) techniques as described by Jenet and Prince in the context of searching for the chirping signals observed during X-ray bursts.

  9. Evaluating Preschool Children Knowledge about Healthy Lifestyle: Preliminary Examination of the Healthy Lifestyle Evaluation Instrument

    ERIC Educational Resources Information Center

    Grammatikopoulos, Vasilis; Konstantinidou, Elisavet; Tsigilis, Nikolaos; Zachopoulou, Evridiki; Tsangaridou, Niki; Liukkonen, Jarmo

    2008-01-01

    The aim of this study was to develop an instrument to evaluate the knowledge of preschool children about healthy lifestyle behavior. The innovation was that the instrument was designed to get direct evidence about healthy lifestyle from children aged 4-6 years old. Usually, children knowledge is estimated indirectly (parents, teachers), but the…

  10. Preliminary Evaluation of MapReduce for High-Performance Climate Data Analysis

    NASA Technical Reports Server (NTRS)

    Duffy, Daniel Q.; Schnase, John L.; Thompson, John H.; Freeman, Shawn M.; Clune, Thomas L.

    2012-01-01

    MapReduce is an approach to high-performance analytics that may be useful to data intensive problems in climate research. It offers an analysis paradigm that uses clusters of computers and combines distributed storage of large data sets with parallel computation. We are particularly interested in the potential of MapReduce to speed up basic operations common to a wide range of analyses. In order to evaluate this potential, we are prototyping a series of canonical MapReduce operations over a test suite of observational and climate simulation datasets. Our initial focus has been on averaging operations over arbitrary spatial and temporal extents within Modern Era Retrospective- Analysis for Research and Applications (MERRA) data. Preliminary results suggest this approach can improve efficiencies within data intensive analytic workflows.

  11. Preliminary development and evaluation of an algae-based air regeneration system

    NASA Technical Reports Server (NTRS)

    Nienow, J. A.

    2000-01-01

    The potential of air regeneration system based on the growth of microalgae on the surface of porous ceramic tubes is evaluated. The algae have been maintained in the system for extended periods, up to 360 days. Preliminary measurements of the photosynthetic capacity have been made for Chlorella vulgaris (UTEX 259), Neospongiococcum punctatum (UTEX 786), Stichococcus sp., and Gloeocapsa sp. Under standard test conditions (photosynthetic photon flux approximately 66 micromoles m-2 s-1, initial CO2 concentration approximately 450 micromoles mol-1), mature tubes remove up to 0.2 micromoles of CO2 per tube per minute. The rate of removal increases with photon flux up to at least 225 micromoles m-2 s-1 (PPF); peak rates of 0.35 micromoles of CO2 per tube per minute have been achieved with Chlorella vulgaris. These rates correspond to between 120 and 210 micromoles of CO2 removed per square meter of projected area per minute.

  12. (11)C-labeling and preliminary evaluation of vortioxetine as a PET radioligand.

    PubMed

    Andersen, Valdemar L; Hansen, Hanne D; Herth, Matthias M; Knudsen, Gitte M; Kristensen, Jesper L

    2014-06-01

    Vortioxetine is a new multi-modal drug against major depressive disorder with high affinity for a range of different serotonergic targets in the CNS. We report the (11)C-labeling of vortioxetine with [(11)C]MeI using a Suzuki-protocol that allows for the presence of an unprotected amine. Preliminary evaluation of [(11)C]vortioxetine in a Danish Landrace pig showed rapid brain uptake and brain distribution in accordance with the pharmacological profile, all though an unexpected high binding in cerebellum was also observed. [(11)C]vortioxetine displayed slow tracer kinetics with peak uptake after 60 min and with limited wash-out from the brain. Further studies are needed but this radioligand may prove to be a valuable tool in unraveling the clinical effects of vortioxetine.

  13. Preliminary evaluation of a two-interval, two-alternative infant behavioral testing procedurea)

    PubMed Central

    Browning, Jenna; Buss, Emily; Leibold, Lori J.

    2014-01-01

    The purpose of this study was to evaluate the feasibility and efficiency of an observer-based, two-interval forced-choice infant psychophysical testing procedure. Ten of 11 infants (7–9 months of age) achieved a criterion of 80%-correct detection of a 50-dB sound pressure level noise band in a single testing session. Fewer trials were needed to reach criterion using the two-interval procedure than previously reported for the single-interval observer-based psychophysical procedure [Olsho, Koch, Halpin, and Carter (1987). Devel. Psychol. 23, 627–640]. These results provide preliminary evidence that the two-interval procedure is feasible and efficient while controlling for observer and listener response bias. PMID:25190427

  14. Sexual violence therapy group in a women's correctional facility: a preliminary evaluation.

    PubMed

    Karlsson, Marie E; Bridges, Ana J; Bell, Jessica; Petretic, Patricia

    2014-06-01

    This pilot study was an evaluation of an 8-week exposure-based therapy group targeting sexual trauma in incarcerated women, an underserved population with high rates of trauma exposure. Preliminary findings from 14 female prisoners showed significant decreases in depressive and anxiety symptoms from pre- to posttreatment. Of the women who were above the screening cutoff for possible posttraumatic stress disorder (PTSD; n = 13), depression (n = 12), and generalized anxiety disorder (GAD; n = 12) at pretreatment, approximately 60% had recovered, meaning they had symptom reductions that placed them below the cutoff at posttreatment (n = 8 for PTSD; n = 8 for depression, and n = 9 for GAD). In addition, 85% of participants reported a clinically significant reduction in depressive symptoms and 50% in GAD symptoms. The findings show promise for successful group treatment of sexual violence sequelae in incarcerated women.

  15. Preliminary evaluation of the effect of a dynamic preferential runway system upon community noise disturbance

    NASA Technical Reports Server (NTRS)

    Patterson, H. P.; Edmiston, R. P.; Connor, W. K.

    1972-01-01

    A dynamic preferential runway system (DPRS) was developed for John F. Kennedy International Airport for the purpose of controlling short term noise exposure in the neighboring communities. The DPRS is a computer-aided procedure for optimum selection of runways from the standpoint of noise and is based upon a community disturbance model which takes into account flyover levels, size of exposed populations, time of day and week, and persistence of overflights. A preliminary evaluation of the DPRS is presented on the basis of social survey data and telephone complaint records, for the trial period of August and September, 1971. Comparative use is made of data taken in a previous survey of the same community areas in 1969.

  16. Preliminary Evaluation of Atomization Characteristics of Improved Biodiesel for Gas Turbine Application

    NASA Astrophysics Data System (ADS)

    Kumaran, P.; Gopinathan, M.; Razali, N. M.; Kuperjans, Isabel; Hariffin, B.; Hamdan, H.

    2013-06-01

    Biodiesel is one of the clean burning alternative fuels derived from natural resources and animal fats which is promising fuel for gas turbine application. However, inferior properties of biodiesel such as high viscosity, density and surface tension results in inferior atomization and high emission, hence impedes the fuel compatible for gas turbine application and emits slightly higher emission pollutants due to inferior atomization. This research work focuses on preliminary evaluation of the atomization characteristics of derived from Malaysian waste cooking oil which is the physical properties are subsequently improved by a microwave assisted post treatment scheme. The results shows with improvement in physical properties achieved through the post treatment, biodiesel exhibits significantly better atomization characteristics in terms of spray angle, spray length, sauter mean diameter and shorter evaporation time compared to the biodiesel before improvement and fossil diesel.

  17. Preliminary safety evaluation of an aircraft impact on a near-surface radioactive waste repository

    SciTech Connect

    Lo Frano, R.; Forasassi, G.; Pugliese, G.

    2013-07-01

    The aircraft impact accident has become very significant in the design of a nuclear facilities, particularly, after the tragic September 2001 event, that raised the public concern about the potential damaging effects that the impact of a large civilian airplane could bring in safety relevant structures. The aim of this study is therefore to preliminarily evaluate the global response and the structural effects induced by the impact of a military or commercial airplane (actually considered as a 'beyond design basis' event) into a near surface radioactive waste (RWs) disposal facility. The safety evaluation was carried out according to the International safety and design guidelines and in agreement with the stress tests requirements for the security track. To achieve the purpose, a lay out and a scheme of a possible near surface repository, like for example those of the El Cabril one, were taken into account. In order to preliminarily perform a reliable analysis of such a large-scale structure and to determine the structural effects induced by such a types of impulsive loads, a realistic, but still operable, numerical model with suitable materials characteristics was implemented by means of FEM codes. In the carried out structural analyses, the RWs repository was considered a 'robust' target, due to its thicker walls and main constitutive materials (steel and reinforced concrete). In addition to adequately represent the dynamic response of repository under crashing, relevant physical phenomena (i.e. penetration, spalling, etc.) were simulated and analysed. The preliminary assessment of the effects induced by the dynamic/impulsive loads allowed generally to verify the residual strength capability of the repository considered. The obtained preliminary results highlighted a remarkable potential to withstand the impact of military/large commercial aircraft, even in presence of ongoing concrete progressive failure (some penetration and spalling of the concrete wall) of the

  18. Evaluation of two-stage system for neutron measurement aiming at increase in count rate at Japan Atomic Energy Agency-Fusion Neutronics Source.

    PubMed

    Shinohara, K; Ishii, K; Ochiai, K; Baba, M; Sukegawa, A; Sasao, M; Kitajima, S

    2014-11-01

    In order to increase the count rate capability of a neutron detection system as a whole, we propose a multi-stage neutron detection system. Experiments to test the effectiveness of this concept were carried out on Fusion Neutronics Source. Comparing four configurations of alignment, it was found that the influence of an anterior stage on a posterior stage was negligible for the pulse height distribution. The two-stage system using 25 mm thickness scintillator was about 1.65 times the count rate capability of a single detector system for d-D neutrons and was about 1.8 times the count rate capability for d-T neutrons. The results suggested that the concept of a multi-stage detection system will work in practice.

  19. Evaluation of two-stage system for neutron measurement aiming at increase in count rate at Japan Atomic Energy Agency-Fusion Neutronics Source

    SciTech Connect

    Shinohara, K. Ochiai, K.; Sukegawa, A.; Ishii, K.; Kitajima, S.; Baba, M.; Sasao, M.

    2014-11-15

    In order to increase the count rate capability of a neutron detection system as a whole, we propose a multi-stage neutron detection system. Experiments to test the effectiveness of this concept were carried out on Fusion Neutronics Source. Comparing four configurations of alignment, it was found that the influence of an anterior stage on a posterior stage was negligible for the pulse height distribution. The two-stage system using 25 mm thickness scintillator was about 1.65 times the count rate capability of a single detector system for d-D neutrons and was about 1.8 times the count rate capability for d-T neutrons. The results suggested that the concept of a multi-stage detection system will work in practice.

  20. Design and optimization of a beam shaping assembly for BNCT based on D-T neutron generator and dose evaluation using a simulated head phantom.

    PubMed

    Rasouli, Fatemeh S; Masoudi, S Farhad

    2012-12-01

    A feasibility study was conducted to design a beam shaping assembly for BNCT based on D-T neutron generator. The optimization of this configuration has been realized in different steps. This proposed system consists of metallic uranium as neutron multiplier, TiF(3) and Al(2)O(3) as moderators, Pb as reflector, Ni as shield and Li-Poly as collimator to guide neutrons toward the patient position. The in-air parameters recommended by IAEA were assessed for this proposed configuration without using any filters which enables us to have a high epithermal neutron flux at the beam port. Also a simulated Snyder head phantom was used to evaluate dose profiles due to the irradiation of designed beam. The dose evaluation results and depth-dose curves show that the neutron beam designed in this work is effective for deep-seated brain tumor treatments even with D-T neutron generator with a neutron yield of 2.4×10(12) n/s. The Monte Carlo Code MCNP-4C is used in order to perform these calculations.

  1. Coupled neutronics and thermal-hydraulics numerical simulations of a Molten Fast Salt Reactor (MFSR)

    NASA Astrophysics Data System (ADS)

    Laureau, A.; Rubiolo, P. R.; Heuer, D.; Merle-Lucotte, E.; Brovchenko, M.

    2014-06-01

    Coupled neutronics and thermalhydraulic numerical analyses of a molten salt fast reactor are presented. These preliminary numerical simulations are carried-out using the Monte Carlo code MCNP and the Computation Fluid Dynamic code OpenFOAM. The main objectives of this analysis performed at steady-reactor conditions are to confirm the acceptability of the current neutronic and thermalhydraulic designs of the reactor, to study the effects of the reactor operating conditions on some of the key MSFR design parameters such as the temperature peaking factor. The effects of the precursor's motion on the reactor safety parameters such as the effective fraction of delayed neutrons have been evaluated.

  2. The evaluation of neutron and gamma ray dose equivalent distributions in patients and the effectiveness of shield materials for high energy photons radiotherapy facilities.

    PubMed

    Ghassoun, J; Senhou, N

    2012-04-01

    In this study, the MCNP5 code was used to model radiotherapy room of a medical linear accelerator operating at 18 MV and to evaluate the neutron and the secondary gamma ray fluences, the energy spectra and the dose equivalent distributions inside a liquid tissue-equivalent (TE) phantom. The obtained results were compared with measured data published in the literature. Moreover, the shielding effects of various neutron material shields on the radiotherapy room wall were also investigated. Our simulation results showed that paraffin wax containing boron carbide presents enough effectiveness to reduce both neutron and secondary gamma ray doses.

  3. Preliminary Evaluation of Removing Used Nuclear Fuel From Nine Shutdown Sites

    SciTech Connect

    Maheras, Steven J.; Best, Ralph; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.; McConnell, Paul

    2013-04-30

    The Blue Ribbon Commission on America’s Nuclear Future identified removal of stranded used nuclear fuel at shutdown sites as a priority so that these sites may be completely decommissioned and put to other beneficial uses. In this report, a preliminary evaluation of removing used nuclear fuel from nine shutdown sites was conducted. The shutdown sites included Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, and Zion. At these sites a total of 7649 used nuclear fuel assemblies and a total of 2813.2 metric tons heavy metal (MTHM) of used nuclear fuel are contained in 248 storage canisters. In addition, 11 canisters containing greater-than-Class C (GTCC) low-level radioactive waste are stored at these sites. The evaluation was divided in four components: • characterization of the used nuclear fuel and GTCC low-level radioactive waste inventory at the shutdown sites • an evaluation of the onsite transportation conditions at the shutdown sites • an evaluation of the near-site transportation infrastructure and experience relevant to the shipping of transportation casks containing used nuclear fuel from the shutdown sites • an evaluation of the actions necessary to prepare for and remove used nuclear fuel and GTCC low-level radioactive waste from the shutdown sites. Using these evaluations the authors developed time sequences of activities and time durations for removing the used nuclear fuel and GTCC low-level radioactive waste from a single shutdown site, from three shutdown sites located close to each other, and from all nine shutdown sites.

  4. Transport analysis of measured neutron leakage spectra from spheres as tests of evaluated high energy cross sections

    NASA Technical Reports Server (NTRS)

    Bogart, D. D.; Shook, D. F.; Fieno, D.

    1973-01-01

    Integral tests of evaluated ENDF/B high-energy cross sections have been made by comparing measured and calculated neutron leakage flux spectra from spheres of various materials. An Am-Be (alpha,n) source was used to provide fast neutrons at the center of the test spheres of Be, CH2, Pb, Nb, Mo, Ta, and W. The absolute leakage flux spectra were measured in the energy range 0.5 to 12 MeV using a calibrated NE213 liquid scintillator neutron spectrometer. Absolute calculations of the spectra were made using version 3 ENDF/B cross sections and an S sub n discrete ordinates multigroup transport code. Generally excellent agreement was obtained for Be, CH2, Pb, and Mo, and good agreement was observed for Nb although discrepancies were observed for some energy ranges. Poor comparative results, obtained for Ta and W, are attributed to unsatisfactory nonelastic cross sections. The experimental sphere leakage flux spectra are tabulated and serve as possible benchmarks for these elements against which reevaluated cross sections may be tested.

  5. Preliminary evaluation of crisis-relocation fallout-shelter options. Volume 2. Detailed analysis

    SciTech Connect

    Santini, D.J.; Clinch, J.M.; Davis, F.H.; Hill, L.G.; Lynch, E.P.; Tanzman, E.A.; Wernette, D.R.

    1982-12-01

    This report presents a preliminary, detailed evaluation of various shelter options for use if the President orders crisis relocation of the US urban population because of strong expectation of a nuclear war. The availability of livable shelter space at 40 ft/sup 2/ per person (congregate-care space) by state is evaluated. Options are evaluated for construction of fallout shelters allowing 10 ft/sup 2/ per person - such shelters are designed to provide 100% survival at projected levels of radioactive fallout. The FEMA concept of upgrading existing buildings to act as fallout shelters can, in principle, provide adequate shelter throughout most of the US. Exceptions are noted and remedies proposed. In terms of upgrading existing buildings to fallout shelter status, great benefits are possible by turning away from a standard national approach and adopting a more site-specific approach. Existing FEMA research provides a solid foundation for successful crisis relocation planning, but the program can be refined by making suitable modifications in its locational, engineering, and institutionally specific elements.

  6. Novel modular 2-DOF microsurgical forceps for transoral laser microsurgeries: Ergonomic design and preliminary evaluation.

    PubMed

    Chauhan, Manish; Barresi, Giacinto; Deshpande, Nikhil; Caldwell, Darwin G; Mattos, Leonardo S

    2016-08-01

    Transoral Laser Microsurgeries (TLM) demand a great level of control and precision in intraoperative tissue manipulation. The optimal eradication of the diseased tissue is possible only with coordinated control of the laser aiming for incision and the microsurgical tools for orienting and stretching the tissue. However, the traditional microsurgical tools are long, single purpose, one degree-of-freedom (DOF), rigid tools with small range of motion and a normal grasping handle inducing non-ergonomic usage. This paper presents a novel, modular microsurgical tool to overcome the challenges of the traditional tools and improve the surgeon-tool usage experience. The novel design adds a rotational DOF to expand the reach and functionality of the tool. The device is provided with an ergonomic grasping handle that avoids extreme wrist excursions and is capable of adapting to the variety of tools used in TLM within the same design. The performance of the new microsurgical tool was evaluated through a subjective assessment with both medical students and expert surgeons. The evaluation demonstrated a general acceptance of the new forceps tool, with the expert surgeons providing positive appraisals for the improved functionality and user experience with the tool, which indicates towards the potential suitability of the device for TLM. The parameters assessed in the preliminary evaluation not only provide a sense of the advantages of the novel design, but also guide future evolution of the tool design.

  7. A preliminary evaluation work on a 3D ultrasound imaging system for 2D array transducer

    NASA Astrophysics Data System (ADS)

    Zhong, Xiaoli; Li, Xu; Yang, Jiali; Li, Chunyu; Song, Junjie; Ding, Mingyue; Yuchi, Ming

    2016-04-01

    This paper presents a preliminary evaluation work on a pre-designed 3-D ultrasound imaging system. The system mainly consists of four parts, a 7.5MHz, 24×24 2-D array transducer, the transmit/receive circuit, power supply, data acquisition and real-time imaging module. The row-column addressing scheme is adopted for the transducer fabrication, which greatly reduces the number of active channels . The element area of the transducer is 4.6mm by 4.6mm. Four kinds of tests were carried out to evaluate the imaging performance, including the penetration depth range, axial and lateral resolution, positioning accuracy and 3-D imaging frame rate. Several strong reflection metal objects , fixed in a water tank, were selected for the purpose of imaging due to a low signal-to-noise ratio of the transducer. The distance between the transducer and the tested objects , the thickness of aluminum, and the seam width of the aluminum sheet were measured by a calibrated micrometer to evaluate the penetration depth, the axial and lateral resolution, respectively. The experiment al results showed that the imaging penetration depth range was from 1.0cm to 6.2cm, the axial and lateral resolution were 0.32mm and 1.37mm respectively, the imaging speed was up to 27 frames per second and the positioning accuracy was 9.2%.

  8. Informationist programme in support of biomedical research: a programme description and preliminary findings of an evaluation

    PubMed Central

    Whitmore, Susan C.; Grefsheim, Suzanne F.; Rankin, Jocelyn A.

    2008-01-01

    Background The informationist programme at the Library of the National Institutes of Health (NIH) in Bethesda, MD, USA has grown to 14 informationists working with 40 clinical and basic science research teams. Purpose This case report, intended to contribute to the literature on informationist programmes, describes the NIH informationist programme including implementation experiences, the informationists' training programme, their job responsibilities and programme outcomes. Brief description The NIH informationist programme was designed to enhance the library's service capacity. Over time, the steps for introducing the service to new groups were formalized to ensure support by leadership, the team being served and the library. Job responsibilities also evolved from traditional library roles to a wide range of knowledge management activities. The commitment by the informationist, the team and the library to continuous learning is critical to the programme's success. Results/outcomes NIH scientists reported that informationists saved them time and contributed to teamwork with expert searching and point-of-need instruction. Process evaluation helped refine the programme. Evaluation method High-level, preliminary outcomes were identified from a survey of scientists receiving informationist services, along with key informant interviews. Process evaluation examined service implementation, informationists' training, and service components. Anecdotal evidence has also indicated a favorable response to the programme. PMID:18494648

  9. Formulation and experimental evaluation of closed-form control laws for the rapid maneuvering of reactor neutronic power

    SciTech Connect

    Bernard, J.A. . Nuclear Reactor Lab.)

    1989-09-01

    This report describes both the theoretical development and the experimental evaluation of a novel, robust methodology for the time-optimal adjustment of a reactor's neutronic power under conditions of closed-loop digital control. Central to the approach are the MIT-SNL Period-Generated Minimum Time Control Laws' which determine the rate at which reactivity should be changed in order to cause a reactor's neutronic power to conform to a specified trajectory. Using these laws, reactor power can be safely raised by five to seven orders of magnitude in a few seconds. The MIT-SNL laws were developed to facilitate rapid increases of neutronic power on spacecraft reactors operating in an SDI environment. However, these laws are generic and have other applications including the rapid recovery of research and test reactors subsequent to an unanticipated shutdown, power increases following the achievement of criticality on commercial reactors, power adjustments on commercial reactors so as to minimize thermal stress, and automated startups. The work reported here was performed by the Massachusetts Institute of Technology under contract to the Sandia National Laboratories. Support was also provided by the US Department of Energy's Division of University and Industry Programs. The work described in this report is significant in that a novel solution to the problem of time-optimal control of neutronic power was identified, in that a rigorous description of a reactor's dynamics was derived in that the rate of change of reactivity was recognized as the proper control signal, and in that extensive experimental trials were conducted of these newly developed concepts on actual nuclear reactors. 43 refs., 118 figs., 11 tabs.

  10. NDP (neutron depth profiling) evaluations of boron-implanted compound semiconductors

    SciTech Connect

    Bowman, R.C.; Knudsen, J.F.; Downing, R.G.

    1988-03-04

    This report describes recent neutron depth profiling (NDP) experiments on the distribution of implanted boron in several semiconductors. The objectives are to compare the boron profiles for different materials that had been simultaneously implanted and to assess the effects of annealing treatments that were used to remove implant damage and electrically activate the boron.

  11. A preliminary evaluation of certain NDA techniques for RH-TRU characterization

    SciTech Connect

    Hartwell, J.K.; Yoon, W.Y.; Peterson, H.K.

    1997-11-01

    This report presents the results of modeling efforts to evaluate selected NDA assay methods for RH-TRU waste characterization. The target waste stream was Content Code 104/107 113-liter waste drums that comprise the majority of the INEL`s RH-TRU waste inventory. Two NDA techniques are treated in detail. One primary NDA technique examined is gamma-ray spectrometry to determine the drum fission and activation product content, and fuel sample inventory calculations using the ORIGEN code to predict the total drum inventory. A heavily shielded and strongly collimated HPGe spectrometer system was designed using MCNP modeling. Detection limits and expected precision of this approach were estimated by a combination of Monte Carlo modeling and synthetic gamma-ray spectrum generation. This technique may allow the radionuclide content of these wastes to be determined with relative standard deviations of 20 to 50% depending on the drum matrix and radionuclide. The INEL Passive/Active Neutron (PAN) assay system is the second primary technique considered. A shielded overpack for the 113-liter CC104/107 RH-TRU drums was designed to shield the PAN detectors from excessive gamma radiation. MCNP modeling suggests PAN detection limits of about 0.06 g {sup 235}U and 0.04 g {sup 239}Pu during active assays. 12 refs., 2 figs., 6 tabs.

  12. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM ANAEROBIC DIGESTER GAS - PHASE I. CONCEPTUAL DESIGN, PRELIMINARY COST, AND EVALUATION STUDY

    EPA Science Inventory

    The report discusses Phase I (a conceptual design, preliminary cost, and evaluation study) of a program to demonstrate the recovery of energy from waste methane produced by anaerobic digestion of waste water treatment sludge. The fuel cell is being used for this application becau...

  13. Preliminary Evaluation of a Social Skills Training and Facilitated Play Early Intervention Programme for Extremely Shy Young Children in China

    ERIC Educational Resources Information Center

    Li, Yan; Coplan, Robert J.; Wang, Yuemin; Yin, Jingtong; Zhu, Jingjing; Gao, Zhuqing; Li, Linhui

    2016-01-01

    The goal of this study was to provide a preliminary evaluation of a social skills and facilitated play early intervention programme to promote social interaction, prosocial behaviours and socio-communicative skills among young extremely shy children in China. Participants were a sample of n = 16 extremely shy young children attending kindergarten…

  14. Preliminary Evaluation of Commercial Off the Shelf (COTS) Packing Materials for Flight Medication Dispenser (FMD) Technology Development

    NASA Technical Reports Server (NTRS)

    Du, B.; Daniels, V.; Crady, C.; Putcha, L.

    2011-01-01

    This slide presentation reviews preliminary results of the program to evaluate Commercial Off the Shelf (COTS) packaging materials for pharmaceutical stability. The need for improved packaging is due to possible changes in chemical and/or physical properties of the drugs, which cause reported reduced potency and/or altered bioavailability and decreased efficacy.

  15. Treatment Integrity Assessment of a Daily Report Card Intervention: A Preliminary Evaluation of Two Methods and Frequencies

    ERIC Educational Resources Information Center

    Sanetti, Lisa M. Hagermoser; Chafouleas, Sandra M.; O'Keeffe, Breda V.; Kilgus, Stephen P.

    2013-01-01

    Although intuitively appealing, teacher self-report of treatment integrity is not currently recommended as a method for collecting treatment integrity data. Education researchers have not, however, evaluated features of a treatment integrity self-reporting system that may facilitate accurate self-report. In this preliminary investigation, four…

  16. R-Matrix Evaluation of Cl Neutron Cross Sections up to 1.2 MeV

    SciTech Connect

    Sayer, R.O.

    2003-03-27

    We have performed an evaluation of {sup 35}Cl, {sup 37}Cl, and {sup nat}Cl neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Resonance analyses were carried out with the computer code SAMMY, which utilizes Bayes' method, a generalized least squares technique. A recent modification of SAMMY enabled us to calculate charged particle penetrabilities for the proton exit channel. Our resonance parameter representation describes the data much better than does ENDF/B-VI, and it should lead to improved criticality safety calculations for systems where Cl is present.

  17. Outcome measures to evaluate new technology for tonsillectomy: preliminary experience with Coblation

    NASA Astrophysics Data System (ADS)

    Shah, Udayan K.; Puchalski, Robert; Briggs, Marianne; Chiavacci, Rosetta; Galinkin, Jeffrey

    2001-05-01

    Evaluating the benefits of new surgical technologies does not end with the observation of successful instrument-to- tissue interaction. The impact of new technologies in medicine today is also gauged by improvements in patients' daily activities and performance. We present our outcomes assessment tool for judging the value of applying a novel tonsillectomy technique, plasma- mediated ablation using Coblation technology. Plasma- mediated ablation (PMA) achieves soft tissue resection in the oropharynx by energizing protons to break bonds. Less heat is released, allowing for less thermal injury, and possibly less pain, than with tonsillectomy performed using electrocautery alone. Children undergoing tonsillectomy by PMA, were evaluated using our outcomes-based scale, which asked families to report the degree of interruption of normal activities for the patient and their family during the post-tonsillectomy recovery period. A preliminary review of several outcomes assessments exemplify the benefits and limitations of this tool. The tracking of valuable data is weighed against the limitations of a short time course relative to the duration of disability, and a poor response rate. Future work aims to improve this data collection tool to allow application to other new technologies in otolaryngology.

  18. A preliminary evaluation of sediment quality assessment values for freshwater ecosystems

    USGS Publications Warehouse

    Smith, Sherri L.; MacDonald, Donald D.; Keenleyside, Karen A.; Ingersoll, Christopher G.; Field, L. Jay

    1996-01-01

    Sediment quality assessment values were developed using a weight of evidence approach in which matching biological and chemical data from numerous modelling, laboratory, and field studies performed on freshwater sediments were compiled and analyzed. Two assessment values (a threshold effect level (TEL) and a probable effect level(PEL)) were derived for 23 substances, including eight trace metals, six individual polycyclic aromatic hydrocarbons (PAHs), total polychlorinated biphenyls (PCBs), and eight pesticides. The two values defined three ranges of chemical concentrations; those that were (1) rarely, (2) occasionally, and (3) frequently associated with adverse biological effects. An evaluation of the percent incidence of adverse biological effects within the three concentration ranges indicated that the reliability of the TELs (i.e., the degree to which the TELs represent concentrations within the data set below which adverse effects rarely occur) was consistently good. However, this preliminary evaluation indicated that most of the PELs were less reliable (i.e., they did not adequately represent concentrations within the data set above which adverse effects frequently occur). Nonetheless, these values were often comparable to other biological effects-based assessment values (which were themselves reliable), which increased the level of confidence that could be placed in our values. This method is being used as a basis for developing national sediment quality guidelines for freshwater systems in Canada and sediment effect concentrations as part of the Assessment and Remediation of Contaminated Sediments (ARCS) program in the Great Lakes.

  19. Assessment of Risk in Chronic Airways Disease Evaluation (ARCADE): Protocol and preliminary data.

    PubMed

    Gale, Nichola S; Albarrati, Ali M; Munnery, Margaret M; Munnery, Iain C; Irfan, Mujammil; Bolton, Charlotte E; Rambaran, Curtis N; Singer, Ruth M Tal; Cockcroft, John R; Shale, Dennis J

    2014-11-01

    Chronic obstructive pulmonary disease (COPD) is a multisystem disease. Established comorbidities include cardiovascular disease, osteoporosis, loss of muscle mass and function, depression, and impaired quality of life. The natural history is not well understood. The Assessment of Risk in Chronic Airways Disease Evaluation (ARCADE) is a longitudinal study of comorbidities in COPD. The primary aims are to delineate the progression and interrelationships of cardiovascular disease and associated comorbidities. Each year ARCADE aims to recruit 250 patients diagnosed with COPD and 50 comparators (free from respiratory disease). Assessments include spirometry, body composition, blood pressure, aortic stiffness (pulse wave velocity (PWV)), noninvasive measures of cardiac output, systemic inflammatory mediators, blood and urine biochemistry, and physical and health outcomes. These will be repeated at 2 and 5 years. In the first year of recruitment, 350 patients and 100 comparators were recruited. The reproducibility of aortic PWV, cardiac output, stroke volume, and cardiac index was evaluated and accepted in 30 patients free from overt cardiovascular disease. The preliminary data from ARCADE have demonstrated acceptable reproducibility of hemodynamic outcome measures. Further longitudinal data collection will increase knowledge of the progression and interactions between cardiovascular risk factors and other comorbidities in COPD.

  20. The Preventing Relational Aggression in Schools Everyday Program: A Preliminary Evaluation of Acceptability and Impact

    PubMed Central

    Leff, Stephen S.; Waasdorp, Tracy Evian; Paskewich, Brooke; Gullan, Rebecca Lakin; Jawad, Abbas F.; MacEvoy, Julie Paquette; Feinberg, Betsy E.; Power, Thomas J.

    2011-01-01

    Despite recent research suggesting that relationally aggressive behaviors occur frequently and may lead to physically aggressive actions within urban school settings, there has been little prior research to develop and evaluate relational aggression prevention efforts within the urban schools. The current article describes the development and preliminary evaluation of the Preventing Relational Aggression in Schools Everyday (PRAISE) Program. PRAISE is a 20-session classroom-based universal prevention program, designed to be appropriate and responsive to the needs of youth within the urban school context. Results suggest strong acceptability for the program and feasibility of implementation. Further, the program was especially beneficial for girls. For instance, girls in classrooms randomly assigned to the PRAISE Program demonstrated higher levels of knowledge for social information processing and anger management techniques and lower levels of relational aggression following treatment as compared to similar girls randomly assigned to a no-treatment control condition. Further, relationally aggressive girls exhibited similar benefits from the program (greater knowledge and lower levels of relational aggression) plus lower levels of overt aggression following treatment as compared to relationally aggressive girls within the control classrooms. In contrast, the program was not associated with improvements for boys across most measures. The significance and implications of the findings for research and practice are discussed. PMID:21686034

  1. Preliminary evaluation of a novel energy-resolved photon-counting gamma ray detector

    PubMed Central

    Meng, L.-J.; Tan, J.W.; Spartiotis, K.; Schulman, T.

    2016-01-01

    In this paper, we present the design and preliminary performance evaluation of a novel energy-resolved photon-counting (ERPC) detector for gamma ray imaging applications. The prototype ERPC detector has an active area of 4.4 cm × 4.4 cm, which is pixelated into 128 × 128 square pixels with a pitch size of 350 µm × 350µm. The current detector consists of multiple detector hybrids, each with a CdTe crystal of 1.1 cm × 2.2 cm × 1 mm, bump-bonded onto a custom-designed application-specific integrated circuit (ASIC). The ERPC ASIC has 2048 readout channels arranged in a 32 × 64 array. Each channel is equipped with pre- and shaping-amplifiers, a discriminator, peak/hold circuitry and an analog-to-digital converter (ADC) for digitizing the signal amplitude. In order to compensate for the pixel-to-pixel variation, two 8-bit digital-to-analog converters (DACs) are implemented into each channel for tuning the gain and offset. The ERPC detector is designed to offer a high spatial resolution, a wide dynamic range of 12–200 keV and a good energy resolution of 3–4 keV. The hybrid detector configuration provides a flexible detection area that can be easily tailored for different imaging applications. The intrinsic performance of a prototype ERPC detector was evaluated with various gamma ray sources, and the results are presented. PMID:28260825

  2. Preliminary geothermal evaluation of the Mokapu Peninsula on the Island of Oahu, Hawaii

    SciTech Connect

    Not Available

    1981-08-01

    Preliminary geological, geochemical, and geophysical field surveys have been conducted on Mokapu Peninsula on the island of Oahu in an effort to determine whether sufficient indications of geothermal potential exist within or adjacent to the peninsula to justify further, more detailed, exploratory efforts. An evaluation of existing geologic data as well as recently completed mapping on Mokapu indicate that the peninsula is located on the edge of or immediately adjacent to the inferred caldera of Koolau volcano. Geochemical surveys conducted within and around the Mokapu Peninsula included mercury and radon ground gas surveys as well as a limited evaluation of groundwater chemistry. Groundwater sampling on Mokapu Peninsula was severely restricted due to the absence of wells within the study area and thus water chemistry analyses were limited to the Nuupia fish ponds. Schlumberger resistivity soundings were completed in three locations on the peninsula: KVS1, in the northeast quadrant within the Ulupau crater, KVS2 in the northwest quadrant along the main jet runway, and KVS3 in the southeast along Mokapu Road. KVS1 encountered a relatively high resistivity to a depth of approximately 20 meters below sea level which was underlain by a basement resistivity of about 2 to 3 ohm meters. KVS2 and KVS3 detected similar resistivities of 2 to 3 ohm meters at much shallower depths (approximately equivalent to local sea level) below a thin, moderately resistive layer having an impedance ranging from 15 to 118 ohm meters.

  3. Antioxidant properties and preliminary evaluation of phytochemical composition of different anatomical parts of amaranth.

    PubMed

    Kraujalis, Paulius; Venskutonis, Petras R; Kraujalienė, Vaida; Pukalskas, Audrius

    2013-09-01

    Antioxidant properties of amaranth extracts isolated sequentially by acetone and methanol/water from defatted plant leaves, flowers, stems and seeds were assessed by ABTS(+•), DPPH(•), ORAC and total phenols content (TPC) assays. In addition, antioxidant properties of solid plant material were evaluated by the direct QUENCHER method using the same assays. Leaves and flowers of amaranth as well as their extracts possessed the highest antioxidant activities. Radical scavenging capacity in ABTS(+•) assay for leaves, flowers, stems and seeds evaluated by QUENCHER method were 144.24 ± 2.41, 112.33 ± 7.45, 19.05 ± 1.13 and 21.82 ± 1.06 μmol trolox equivalents in 1 g of dry weight, respectively. On-line HPLC-DPPH(•) assay was used to determine the activity of separated compounds and it was observed that rutin was the main radical scavenger in amaranth extracts. Preliminary screening of extract composition was performed by UPLC/ESI-QTOF-MS and rutin, nicotiflorin, isoquercitrin, 4-hydroxybenzoic and p-coumaric acids were identified by measuring their accurate mass and retention time.

  4. Evaluation of a neutron-photon shield for transuranic (TRU) waste containers

    SciTech Connect

    Wishau, R. J.; Gallegos, M.; Ruby, R.; Sullivan, E. J.

    2004-01-01

    The Los Alamos National Laboratory (LANL) Operational Health Physics Group, with the support of the Nuclear Materials Technology Waste Management Group, has developed a wrap-around shield for use with 0.208 cubic meter (55 gallon) drums containing transuranic (TRU) waste. The shield or 'drum cover' as it is called, is innovative in its ability to attenuate both neutron and photon radiation associated with TRU waste. This poster presents information on the design, fabrication and field use of the drum cover. Design details to be presented include the composition of the shield including the materials used, thicknesses, weight, dimensions and fastener arrangement. Information on the source supplier for the shield materials, the fabrication vendor and the drum cover cost are provided. Shielding data show the unique effectiveness of the drum cover and its ability to reduce neutron and photon radiation exposures as low as reasonably achievable (ALARA). These data include x-ray testing of the assembled shield materials, as well as field experience report on the drum cover using TRU waste containers and neutron source drums. The poster includes discussion and photographs of recent field uses for the drum cover, user experience and acceptance of the drum cover and suggestions for future use and enhancement of the drum cover design.

  5. The performance evaluation of gamma- and neutron-sensitive superheated emulsion (bubble) detectors.

    PubMed

    Vaijapurkar, S G; Senwar, Kana Ram; Hooda, J S; Parihar, A

    2008-01-01

    The superheated emulsion (bubble) detectors have been developed at Defence Laboratory, Jodhpur (DLJ), India, for measurement of gamma doses. The developed detectors have been tested at Radiation Safety and System Division (RSSD), Bhabha Atomic Research Center (BARC), Mumbai (India) and DLJ having ISO-17025 accredited facility for testing and calibration of Radiation Monitors. A series of experiments were conducted to determine the gamma and neutron sensitivity of these detectors, i.e. batch homogeneity, reproducibility, dose equivalent rate effect, gamma/neutron dose equivalent response, gamma/neutron energy response and change in gamma sensitivity as a function of temperature. All the results were within +/- 20% of themselves. It is observed that the response of the detector is dependent upon temperature. The recommended ideal working temperature range of the detector is 20-28 degrees C, but a temperature correction is required beyond approximately 30 masculineC. The temperature compensation may be possible up to 45 degrees C in improved version using specially prepared reversible thermo-sensitive polymer gel. The detector may have applications in radio-diagnosis, R&D laboratories, and health physics as well as an indicator of gamma radiation for dirty bomb to be useful for first responder in any radiological emergency.

  6. Evaluation of gamma-ray exposure buildup factors and neutron shielding for bismuth borosilicate glasses

    NASA Astrophysics Data System (ADS)

    Singh, Vishwanath P.; Badiger, N. M.; Chanthima, N.; Kaewkhao, J.

    2014-05-01

    Gamma-ray exposure buildup factor (EBF) values and neutron shielding effectiveness of bismuth borosilicate (BBS) glass systems in composition (50-x)SiO2:15B2O3:2Al2O3:10CaO:23Na2O:xBi2O3 (where x=0, 5, 10, 15 and 20 mol%) were calculated. The EBF values were computed for photon energy 0.015-15 MeV up to penetration depths of 40 mfp (mean free path) by the geometrical progression (G-P) method. The EBF values were found dependent upon incident photon energy, penetration and bismuth molar concentration. In low- and high-energy photon regions, the EBF values were minimum whereas maximum in the intermediate-energy region. The fast neutron removal cross sections for energy 2-12 MeV were calculated by the partial density method. The BBS glass with 20 mol% Bi2O3 is found to be superior gamma-ray and neutron transparent shielding. The EBF values of the BBS glasses were compared with steel-magnetite concrete and lead. The investigation was carried out to explore the advantages of the BBS glasses in different radiation shielding applications.

  7. Preliminary 3D In-situ measurements of the texture evolution of strained H2O ice during annealing using neutron Laue diffractometry

    NASA Astrophysics Data System (ADS)

    Journaux, Baptiste; Montagnat, Maurine; Chauve, Thomas; Ouladdiaf, Bachir; Allibon, John

    2015-04-01

    Dynamic recrystallization (DRX) strongly affects the evolution of microstructure (grain size and shape) and texture (crystal preferred orientation) in materials during deformation at high temperature. Since texturing leads to anisotropic physical properties, predicting the effect of DRX is essential for industrial applications, for interpreting geophysical data and modeling geodynamic flows, and predicting ice sheet flow and climate evolution. A large amount of literature is available related to metallurgy, geology or glaciology, but there remains overall fundamental questions about the relationship between nucleation, grain boundary migration and texture development at the microscopic scale. Previous measurements of DRX in ice were either conducted using 2D ex-situ techniques such as AITA [1,2] or Electron Backscattering Diffraction (EBSD) [3], or using 3D statistical ex-situ [4] or in-situ [5] techniques. Nevertheless, all these techniques failed to observe at the scale of nucleation processes during DRX in full 3D. Here we present a new approach using neutron Laue diffraction, which enable to perform 3D measurements of in-situ texture evolution of strained polycrystalline H2O ice (>2% at 266 K) during annealing at the microscopic scale. Thanks the CYCLOPS instrument [6] (Institut Laue Langevin Grenoble, France) and the intrinsic low background of this setup, preliminary observations enabled us to follow, in H2O ice, the evolution of serrated grain boundaries, and kink-band during annealing. Our observations show a significant evolution of the texture and internal misorientation over the course of few hours at an annealing temperature of 268.5 K. In the contrary, ice kink-band structures seem to be very stable over time at near melting temperatures. The same samples have been analyzed ex-situ using EBSD for comparison. These results represent a first step toward in-situ microscopic measurements of dynamic recrystallization processes in ice during strain. This

  8. Case study of preliminary cyclic load evaluation and triaxial soil testing in offshore wind farm planning

    NASA Astrophysics Data System (ADS)

    Otto, Daniel; Ossig, Benjamin; Kreiter, Stefan; Kouery, Saed; Moerz, Tobias

    2010-05-01

    In 2020 Germany aims to produce 20% of its electrical power trough renewable energy sources. Assigned Offshore Wind farms in the German exclusive economic zone of the North- and the Baltic Sea are important step toward a fulfilment of this goal. However the save erecting of 5-6 MW wind power plants (total construction size: > 200m) in water depth of around 40 m is related to unprecedented technical, logistical and financial challenges. With an intended lifetime expectation of 50 years for the foundations, construction materials and the soils around the foundation are subject to high and continued stresses from self-weight, waves, wind and current. These stresses are not only static, but have also a significant cyclic component. An estimated 250 million cyclic load changes may lead to an accumulation of plastic deformation in the soil that potentially may affect operability or lifespan of the plant. During a preliminary geotechnical site survey of one of the largest (~150 km2) offshore wind project sites within the German Bight (~45 km North off the island Juist) a total of 16 drill cores with in situ cone penetration data and a total sample length of ~800 m where recovered. Preliminary foundation designs and static self weight and lateral load calculations were used to design a cycling triaxial lab testing program on discrete natural soil samples. Individual tests were performed by foundation type and at vertical and lateral load maxima to evaluate the long-term soil behaviour under cyclic load. Tests have been performed on granular, cohesive and intermediate natural soils. Following an introduction to the unique MARUM triaxial apparatus and testing conditions, the cyclic triaxial test results are shown and explained. Furthermore cyclic shear strength and stiffness are compared to their static counterparts. Unique soil behaviour like abrupt partial failure, pore pressure response and unexpected in part load independent cyclic deformation behaviour is discussed and

  9. Neutronic evaluation of fissile fuel breeding blankets for the fission-suppressed Tandem-Mirror Hybrid Reactor

    SciTech Connect

    Johnson, J.O.; Burns, T.J.

    1984-06-01

    A computational study was performed on the blanket design of the Lawrence Livermore National Laboratory (LLNL) fission-suppressed Tandem Mirror Hybrid Reactor (TMHR) to qualify the methods and data bases available at Oak Ridge National Laboratory (ORNL) for use in analyzing the neutronic performance of fissile fuel breeding blankets. The eventual goal of the study was to establish the capability for analysis and optimization of advanced fissile fuel production blanket designs. Discrete ordinates radiation transport calculations were performed in one-dimensional cylindrical geometry to obtain the blanket spatial distribution and energy spectra of the neutron and gamma-ray fluxes resulting from the monoenergetic (14.1 MeV) fusion first wall source. Key macroscopic cross sections of the blanket materials were then folded with the flux spectra to obtain reaction rates critical to evaluating blanket feasibility. Finally, a time-dependent depletion analysis was performed to evaluate the blanket performance during equilibrium cycle conditions. The results of the study are presented both as graphs and tables.

  10. Preliminary evaluation of a high-resolution workstation for diagnostic interpretation of portable radiographs

    NASA Astrophysics Data System (ADS)

    Honeyman-Buck, Janice C.; Huda, Walter; Palmer, Carole K.; Frost, Meryll M.; Moser, Robert; Staab, Edward V.

    1995-04-01

    A cost effectiveness study on the feasibility of using computed radiography (CR) instead of screen-film methods for portable radiographs indicates that we could only justify CR if film were eliminated. Before purchasing CR equipment, we needed to evaluate the use of softcopy to replace film for routine clinical use. The evaluation had to cover image quality, human factors, and efficiency measures. Screen-film radiographs were digitized and used to simulate CR in two studies. The first study evaluated the quality of digitized images and the workstation user interface. Twenty-one radiographs were selected at random from scopes in the radiology department, were digitized, and transferred to a megascan workstation. Five radiologists were asked to assess the quality of the images and the ease of operation of the workstation while an observer recorded their comments and scores. The second study evaluated the feasibility of using the workstation in a clinical environment. Four radiologists read adult and pediatric portable images in film and softcopy format. Reports were evaluated for differences and timing statistics were kept. The results of the first study indicate that image quality may be acceptable for diagnostic purposes and suggests some changes in the user interface. Newborn infant images were the least acceptable in softcopy, largely due to magnification artifacts introduced when viewing very small images. The evaluation was based on a digitizer as a simulator for a CR unit and the digitizer did not exhibit the same resolution characteristics as CR. Films that were unacceptable from the digitizer are expected to be acceptable with CR. The results of the second study indicated that the high resolution diagnostic workstation could be used in a clinical setting, and that the diagnostic readings were not significantly different between film and softcopy displays. The results also indicated that, depending on the radiologist and the type of images, more time was

  11. Partitioning planning studies: Preliminary evaluation of metal and radionuclide partitioning the high-temperature thermal treatment systems

    SciTech Connect

    Liekhus, K.; Grandy, J.; Chambers, A.

    1997-03-01

    A preliminary study of toxic metals and radionuclide partitioning during high-temperature processing of mixed waste has been conducted during Fiscal Year 1996 within the Environmental Management Technology Evaluation Project. The study included: (a) identification of relevant partitioning mechanisms that cause feed material to be distributed between the solid, molten, and gas phases within a thermal treatment system; (b) evaluations of existing test data from applicable demonstration test programs as a means to identify and understand elemental and species partitioning; and, (c) evaluation of theoretical or empirical partitioning models for use in predicting elemental or species partitioning in a thermal treatment system. This preliminary study was conducted to identify the need for and the viability of developing the tools capable of describing and predicting toxic metals and radionuclide partitioning in the most applicable mixed waste thermal treatment processes. This document presents the results and recommendations resulting from this study that may serve as an impetus for developing and implementing these predictive tools.

  12. Extracting equation of state parameters from black hole-neutron star mergers: Aligned-spin black holes and a preliminary waveform model

    NASA Astrophysics Data System (ADS)

    Lackey, Benjamin D.; Kyutoku, Koutarou; Shibata, Masaru; Brady, Patrick R.; Friedman, John L.

    2014-02-01

    Information about the neutron-star equation of state is encoded in the waveform of a black hole-neutron star system through tidal interactions and the possible tidal disruption of the neutron star. During the inspiral this information depends on the tidal deformability Λ of the neutron star, and we find that the best-measured parameter during the merger and ringdown is consistent with Λ as well. We performed 134 simulations where we systematically varied the equation of state as well as the mass ratio, neutron star mass, and aligned spin of the black hole. Using these simulations we develop an analytic representation of the full inspiral-merger-ringdown waveform calibrated to these numerical waveforms; we use this analytic waveform and a Fisher matrix analysis to estimate the accuracy to which Λ can be measured with gravitational-wave detectors. We find that although the inspiral tidal signal is small, coherently combining this signal with the merger-ringdown matter effect improves the measurability of Λ by a factor of ˜3 over using just the merger-ringdown matter effect alone. However, incorporating correlations between all the waveform parameters then decreases the measurability of Λ by a factor of ˜3. The uncertainty in Λ increases with the mass ratio, but decreases as the black hole spin increases. Overall, a single Advanced LIGO detector can only marginally measure Λ for mass ratios Q =2-5, black hole spins JBH/MBH2=-0.5-0.75, and neutron star masses MNS=1.2M⊙-1.45M⊙ at an optimally oriented distance of 100 Mpc. For the proposed Einstein Telescope, however, the uncertainty in Λ is an order of magnitude smaller.

  13. Preliminary evaluation of a heat pipe heat exchanger on a regenerative turbofan

    NASA Technical Reports Server (NTRS)

    Kraft, G. A.

    1975-01-01

    A preliminary evaluation was made of a regenerative turbofan engine using a heat pipe heat exchanger. The heat exchanger had an effectiveness of 0.70, a pressure drop of 3 percent on each side, and used sodium for the working fluid in the stainless steel heat pipes. The engine was compared to a reference turbofan engine originally designed for service in 1979. Both engines had a bypass ratio of 4.5 and a fan pressure ratio of 2.0. The design thrust of the engines was in the 4000 N range at a cruise condition of Mach 0.98 and 11.6 km. It is shown that heat pipe heat exchangers of this type cause a large weight and size problem for the engine. The penalties were too severe to be overcome by the small uninstalled fuel consumption advantage. The type of heat exchanger should only be considered for small airflow engines in flight applications. Ground applications might prove more suitable and flexible.

  14. Inherited pelvic organ prolapse in the mouse: preliminary evaluation of a new murine model

    PubMed Central

    MCNANLEY, Anna R.; JOHNSON, Aimee M.; FLYNN, Michael K.; WOOD, Ronald W.; KENNEDY, Scott D.; REEDER, Jay E.

    2013-01-01

    Objectives/Introduction To report the initial anatomic, radiographic, and genetic evaluations of a novel form of spontaneous pelvic organ prolapse (S-POP) in mice. Methods We observed S-POP in a colony of UPII-SV40T transgenic mice developed for studies on bladder cancer. We utilized magnetic resonance imaging and necropsy to characterize this finding. We have established a breeding colony to identify inheritance patterns and for future studies. Results Selective breeding isolated the S-POP phenotype from the transgene. In contrast to other animal models, the S-POP mouse does not require an obligatory antecedent event to manifest pelvic organ prolapse. Necropsy and imaging demonstrate significant displacement of the pelvic organs distal to the pelvic floor in both sexes. The appearance of the POP is similar to that seen in the human female phenotype. Preliminary breeding studies indicate an autosomal dominant inheritance pattern. Conclusions This mouse may be an effective animal model for the study of POP in humans. PMID:18802654

  15. A preliminary clinical evaluation of external snehan and asanas in the patients of sciatica

    PubMed Central

    Singh, Akhilesh K; Singh, Om P

    2013-01-01

    Lower back pain radiating to either on one leg or both legs along the course of sciatic nerve is a common ailment in the clinical practice, this type of peculiar symptomatology is termed as "Sciatica" in modern medicine. The medical treatment is unsatisfactory for both the patient and the neurosurgeons, as the surgical treatment has its own hazards and the cost of the surgical procedure and medical treatment is prohibitory to most of the Indian patients. Hence, most of the patients present themselves to the practitioners of Indian medicines like Ayurveda and yoga. This study was designed to evaluate the preliminary clinical effects of Bahya Snehan and Asanas in the patients of sciatica. This was a prospective randomized active control trial. A total of 60 participants showing classical symptoms of Sciatica between 18 and 65 years of age were randomly assigned to receive Ayurvedic or Yogic measure. One group received Snehan (external) with Bhujang and Shalabh Asana while another group received Bhujang and Salabh Asana only. Both groups practiced supervised intervention for 4 weeks. The signs and symptoms like Katishool (pain), tenderness, Stambha (rigidity), difficulty in walking, pain on bending forward were graded and interpreted at the end of the trail Significant improvement was observed in both groups before and after external Snehan with Bhujang and Shalabh Asana and in another group Bhujang and Salabh Asana only. Conclusions: Both groups, one with Snehan with asanas and the second with asanas only showed significant improvement in the patients of sciatica (Gridhrasi). PMID:23439799

  16. Preliminary Evaluation of Probiotic Properties of Lactobacillus Strains Isolated from Sardinian Dairy Products

    PubMed Central

    Pisano, Maria Barbara; Viale, Silvia; Conti, Stefania; Deplano, Maura; Melis, Maria Paola; Deiana, Monica

    2014-01-01

    Twenty-three Lactobacillus strains of dairy origin were evaluated for some functional properties relevant to their use as probiotics. A preliminary subtractive screening based on the abilities to inhibit the growth of microbial pathogens and hydrolyze conjugated bile salts was applied, and six strains were selected for further characterization including survival under gastrointestinal environmental conditions, adhesion to gut epithelial tissue, enzymatic activity, and some safety properties. All selected strains maintained elevated cell numbers under conditions simulating passage through the human gastrointestinal tract, well comparable to the values obtained for the probiotic strain Lactobacillus rhamnosus GG, and were able to adhere to Caco-2 cells to various extents (from 3 to 20%). All strains exhibited high aminopeptidase, and absent or very low proteolytic and strong β-galactosidase activities; none was found to be haemolytic or to produce biogenic amines and all were susceptible to tetracycline, chloramphenicol, erythromycin, ampicillin, and amoxicillin/clavulanic acid. Our results indicate that the Lactobacillus strains analyzed could be considered appropriate probiotic candidates, due to resistance to GIT simulated conditions, antimicrobial activity, adhesion to Caco-2 cell-line, and absence of undesirable properties. They could be used as adjunct cultures for contributing to the quality and health related functional properties of dairy products. PMID:25054135

  17. Preliminary evaluation of PTSD Coach, a smartphone app for post-traumatic stress symptoms.

    PubMed

    Kuhn, Eric; Greene, Carolyn; Hoffman, Julia; Nguyen, Tam; Wald, Laura; Schmidt, Janet; Ramsey, Kelly M; Ruzek, Josef

    2014-01-01

    PTSD Coach is a mobile application (app) designed to help individuals who have post-traumatic stress disorder (PTSD) symptoms better understand and self-manage their symptoms. It has wide-scale use (over 130,000 downloads in 78 countries) and very favorable reviews but has yet to be evaluated. Therefore, this study examines user satisfaction, perceived helpfulness, and usage patterns of PTSD Coach in a sample of 45 veterans receiving PTSD treatment. After using PTSD Coach for several days, participants completed a survey of satisfaction and perceived helpfulness and focus groups exploring app use and benefit from use. Data indicate that participants were very satisfied with PTSD Coach and perceived it as being moderately to very helpful with their PTSD symptoms. Analysis of focus group data resulted in several categories of app use: to manage acute distress and PTSD symptoms, at scheduled times, and to help with sleep. These findings offer preliminary support for the acceptability and perceived helpfulness of PTSD Coach and suggest that it has potential to be an effective self-management tool for PTSD. Although promising, future research is required to validate this, given study limitations.

  18. Investigation of human exposure to triclocarban after showering and preliminary evaluation of its biological effects.

    PubMed

    Schebb, Nils Helge; Inceoglu, Bora; Ahn, Ki Chang; Morisseau, Christophe; Gee, Shirley J; Hammock, Bruce D

    2011-04-01

    The antibacterial soap additive triclocarban (TCC) is widely used in personal care products. TCC has a high environmental persistence. We developed and validated a sensitive online solid-phase extraction-LC-MS/MS method to rapidly analyze TCC and its major metabolites in urine and other biological samples to assess human exposure. We measured human urine concentrations 0-72 h after showering with a commercial bar soap containing 0.6% TCC. The major route of renal elimination was excretion as N-glucuronides. The absorption was estimated at 0.6% of the 70±15 mg of TCC in the soap used. The TCC-N-glucuronide urine concentration varied widely among the subjects, and continuous daily use of the soap led to steady state levels of excretion. In order to assess potential biological effects arising from this exposure, we screened TCC for the inhibition of human enzymes in vitro. We demonstrate that TCC is a potent inhibitor of the enzyme soluble epoxide hydrolase (sEH), whereas TCC's major metabolites lack strong inhibitory activity. Topical administration of TCC at similar levels to rats in a preliminary in vivo study, however, failed to alter plasma biomarkers of sEH activity. Overall the analytical strategy described here revealed that use of TCC soap causes exposure levels that warrant further evaluation.

  19. Development and Preliminary Evaluation of a Spray Deposition Sensing System for Improving Pesticide Application.

    PubMed

    Kesterson, Melissa A; Luck, Joe D; Sama, Michael P

    2015-12-17

    An electronic, resistance-based sensor array and data acquisition system was developed to measure spray deposition from hydraulic nozzles. The sensor surface consisted of several parallel tin plated copper traces of varying widths with varying gap widths. The system contained an embedded microprocessor to monitor output voltage corresponding to spray deposition every second. In addition, a wireless module was used to transmit the voltage values to a remote laptop. Tests were conducted in two stages to evaluate the performance of the sensor array in an attempt to quantify the spray deposition. Initial tests utilized manual droplet placement on the sensor surface to determine the effects of temperature and droplet size on voltage output. Secondary testing utilized a spray chamber to pass nozzles at different speeds above the sensor surface to determine if output varied based on different application rates or spray droplet classification. Results from this preliminary analysis indicated that manual droplets of 5 and 10 μL resulted in significantly different values from the sensors while temperature did not consistently affect output. Spray chamber test results indicated that different application rates and droplet sizes could be determined using the sensor array.

  20. Design and preliminary evaluation of an exoskeleton for upper limb resistance training

    NASA Astrophysics Data System (ADS)

    Wu, Tzong-Ming; Chen, Dar-Zen

    2012-06-01

    Resistance training is a popular form of exercise recommended by national health organizations, such as the American College of Sports Medicine (ACSM) and the American Heart Association (AHA). This form of training is available for most populations. A compact design of upper limb exoskeleton mechanism for homebased resistance training using a spring-loaded upper limb exoskeleton with a three degree-of-freedom shoulder joint and a one degree-of-freedom elbow joint allows a patient or a healthy individual to move the upper limb with multiple joints in different planes. It can continuously increase the resistance by adjusting the spring length to train additional muscle groups and reduce the number of potential injuries to upper limb joints caused by the mass moment of inertia of the training equipment. The aim of this research is to perform a preliminary evaluation of the designed function by adopting an appropriate motion analysis system and experimental design to verify our prototype of the exoskeleton and determine the optimal configuration of the spring-loaded upper limb exoskeleton.

  1. Preliminary evaluation of a new fibre-optic cerebral oximetry system.

    PubMed

    Phillips, J P; Langford, R M; Kyriacou, P A; Jones, D P

    2008-12-01

    A new system for measuring the oxygen saturation of blood within tissue has been developed, for a variety of patient monitoring applications. A particular unmet need is in the central nervous system, and this project aims to devise a means for measuring blood oxygen saturation in the brain tissue of patients recovering from neurosurgery or head injury. Coupling light sources and a photodetector to optical fibres results in a probe small enough to pass through a cranial bolt of the type already in use for intra-cranial pressure monitoring. The development and evaluation of a two-wavelength fibre-optic reflectance photoplethysmography (PPG) system are described. It was found that good quality red and near-infrared PPG signals could be obtained from the finger using a fibre-optic probe. Experiments were conducted to find the inter-fibre spacings that yield signals most suitable for calculating oxygen saturation. Reliable signals could be obtained for inter-fibre spacings between 2 mm and 5 mm, the latter being the size of the maximum aperture in the cranial bolt. A preliminary measurement from human brain tissue is also presented.

  2. Preliminary evaluation of potential substitutes for chlorofluorocarbon refrigerants at Lawrence Livermore National Laboratory

    SciTech Connect

    Rogozen, M.B. )

    1989-12-30

    Chlorofluorocarbons (CFCs) are organic compounds composed of carbon, chlorine and fluorine. CFCs are widely used as refrigerants, solvents, and blowing agents, and, although they are chemically inert in the lower atmosphere, CFCs break apart upon reaching the stratosphere and release chlorine, which destroys ozone molecules that serve as the earth's natural barrier to harmful ultraviolet radiation. Growing concern about the damage to stratospheric ozone has led to an international treaty to limit production and use of certain chlorofluorocarbons. Since the use of CFCs is so extensive, major efforts are under way to identify, test, and commercialize CFC substitutes. The objectives of the preliminary investigation reported here were to identify likely substitutes for CFCs used a refrigerants at Lawrence Livermore National Laboratory (LLNL), and to evaluate current information on their feasibility and health effects. Section 2 contains a brief discussion of the regulatory background. Section 3 describes the chlorofluorocarbon refrigerants currently used at LLNL. Substitutes are identified and discussed in Section 4. Section 5 contains recommendations for further research, and references are presented in Section 6. 29 refs., 3 figs., 3 tabs.

  3. A Preliminary Evaluation of Using Fill Materials to Stabilize Used Nuclear Fuel During Storage and Transportation

    SciTech Connect

    Maheras, Steven J.; Best, Ralph; Ross, Steven B.; Lahti, Erik A.; Richmond, David J.

    2012-08-01

    This report contains a preliminary evaluation of potential fill materials that could be used to fill void spaces in and around used nuclear fuel contained in dry storage canisters in order to stabilize the geometry and mechanical structure of the used nuclear fuel during extended storage and transportation after extended storage. Previous work is summarized, conceptual descriptions of how canisters might be filled were developed, and requirements for potential fill materials were developed. Elements of the requirements included criticality avoidance, heat transfer or thermodynamic properties, homogeneity and rheological properties, retrievability, material availability and cost, weight and radiation shielding, and operational considerations. Potential fill materials were grouped into 5 categories and their properties, advantages, disadvantages, and requirements for future testing were discussed. The categories were molten materials, which included molten metals and paraffin; particulates and beads; resins; foams; and grout. Based on this analysis, further development of fill materials to stabilize used nuclear fuel during storage and transportation is not recommended unless options such as showing that the fuel remains intact or canning of used nuclear fuel do not prove to be feasible.

  4. Ultra-high-speed studies of shock phenomena in a miniaturized system: A preliminary evaluation

    SciTech Connect

    Trott, W.M.; Erickson, K.L.

    1997-09-01

    A laboratory-scale experimental test system for small-scale of shock phenomena has been assembled. This system uses a variety of miniature test platforms in which shock loading is provided by laser-driven flyer impact. Acceptor materials include thin-film explosives and high-density metal foils. Optical access is provided for high-speed optical diagnostics such as optically recording velocity interferometry and single-pulse Raman spectroscopy. The experimental assembly for Raman studies features a common laser source for both flyer generation and excitation of Raman scattering (to achieve high timing precision) and a detection scheme that uses the coupling fiber for the excitation source to collect with high efficiency backscattered Raman light. Preliminary system evaluation experiments indicate that detailed particle velocity studies of the dynamic material properties of high-density metals under short-pulse, high-strain-rate loading can be performed in a miniaturized test configuration. Single-pulse Raman studies on shock compressed thin film explosives also appear feasible if the thickness and grain structure of these films can be tailored to enhance the Raman scattering signal sufficiently. Possible improvements in the experimental design and a number of likely applications of these techniques are also discussed.

  5. Evaluation of the 232Th Neutron Cross Sections between 4 keV and 140 keV

    SciTech Connect

    Volev, K.; Koyumdjieva, N.; Brusegan, A.; Borella, A.; Siegler, P.; Schillebeeckx, P.; Janeva, N.; Lukyanov, A.; Leal, L.

    2005-05-24

    An evaluation of the 232Th neutron total and capture cross sections has been performed in the energy region between 4 keV and 140 keV. The evaluation results from a simultaneous analysis of capture, transmission, and self-indication measurement data, including the most recent capture cross-section data obtained at the GELINA facility of the Institute for Reference Materials and Measurements at Geel (B) and at the n-TOF facility at CERN (CH). The experimental data have been analysed in terms of average resonance parameters exploiting two independent theoretical approaches -- the Characteristic Function model and the Hauser-Feshbach-Moldauer theory. The resulting parameters are consistent with the resolved resonance parameters deduced from the transmission measurements of Olsen et al. at the ORELA facility.

  6. Characterization of a Pulse Neutron Source Yield under Field Conditions

    SciTech Connect

    Barzilov, Alexander; Novikov, Ivan; Womble, Phillip C.; Hopper, Lindsay

    2009-03-10

    Technique of rapid evaluation of a pulse neutron sources such as neutron generators under field conditions has been developed. The phoswich sensor and pulse-shape discrimination techniques have been used for the simultaneous measurements of fast neutrons, thermal neutrons, and photons. The sensor has been calibrated using activation neutron detectors and a pulse deuterium-tritium fusion neutron source.

  7. Evaluation of the characteristics of the neutron reference field using D2O-moderated 252Cf source.

    PubMed

    Kowatari, M; Fujii, K; Takahashi, M; Yoshizawa, M; Shimizu, S; Kawasaki, K; Yamaguchi, Y

    2007-01-01

    The ambient/personal dose equivalent per fluence for D(2)O moderated (252)Cf neutron source was determined by measurement. An appropriate subtraction of the scattered neutrons is required for the accurate measurement of direct neutrons. A cubic shadow object was used for the subtraction of the scattered neutrons from the surroundings. The scattered neutrons to be subtracted vary with the position of the shadow object due to the large volume of the source. Using the Monte Carlo code MCNP-4C, the optimum positions of the shadow object were surveyed for subtracting the scattered neutrons. The energy spectra of direct neutrons were measured in the optimum position. The dosimetric parameters for the D(2)O moderated (252)Cf neutron source were reasonable, taking into account the uncertainties of the parameters.

  8. Bruyères-le-Châtel Neutron Evaluations of Actinides with the TALYS Code: The Fission Channel

    NASA Astrophysics Data System (ADS)

    Romain, P.; Morillon, B.; Duarte, H.

    2016-01-01

    For several years, various neutron evaluations of plutonium and uranium isotopes have been performed at Bruyères-le-Châtel (BRC), from 1 keV up to 30 MeV. Since only nuclear reaction models have been used to produce these evaluations, our approach was named the "Full Model" approach. Total, shape elastic and direct inelastic cross sections were obtained from the coupled channels model using a dispersive optical potential developed for actinides, with a large enough coupling scheme including the lowest octupolar band. All other cross sections were calculated using the Hauser-Feshbach theory (TALYS code) with a pre-equilibrium component above 8-10 MeV. In this paper, we focus our attention on the fission channel. More precisely, we will present the BRC contribution to fission modeling and the philosophy adopted in our "Full Model" approach. Performing evaluations with the "Full Model" approach implies the optimization of a large number of model parameters. With increasing neutron incident energy, many residual nuclei produced by nucleon emission also lead to fission. All available experimental data assigned to various fission mechanisms of the same nucleus were used to determine fission barrier parameters. For uranium isotopes, triple-humped fission barriers were required in order to reproduce accurately variations of the experimental fission cross sections. Our BRC fission modeling has shown that the effects of the class II or class III states located in the wells of the fission barrier sometimes provide an anti-resonant transmission rather than a resonant one. Consistent evaluations were produced for a large series of U and Pu isotopes. Resulting files were tested against integral data.

  9. Evaluation of homogeneity of a certified reference material by instrumental neutron activation analysis

    SciTech Connect

    Kratochvil, B.; Duke, M.J.M.; Ng, D.

    1986-01-01

    The homogeneity of the marine reference material TORT-1, a spray-dried and acetone-extracted hepatopancreatic material from the lobster, was tested for 26 elements by instrumental neutron activation analysis (INAA). Through a one-way analysis of variance based on six analyses on each of six bottles of TORT-1, it was concluded that the between-bottle heterogeneity is no greater than the within-bottle heterogeneity. The analytical results for those elements for which values were provided by NRC agree with the NRC values within 95% confidence limits. 8 references, 6 tables.

  10. A Mobile App to Aid Smoking Cessation: Preliminary Evaluation of SmokeFree28

    PubMed Central

    Wong, Wai Chi

    2015-01-01

    Background Little is known about the effectiveness of mobile apps in aiding smoking cessation or their validity for automated collection of data on smoking cessation outcomes. Objective We conducted a preliminary evaluation of SF28 (SF28 is the name of the app, short for SmokeFree28)—an app aimed at helping smokers to be smoke-free for 28 days. Methods Data on sociodemographic characteristics, smoking history, number of logins, and abstinence at each login were uploaded to a server from SF28 between August 2012 and August 2013. Users were included if they were aged 16 years or over, smoked cigarettes at the time of registration, had set a quit date, and used the app at least once on or after their quit date. Their characteristics were compared with data from a representative sample of smokers trying to stop smoking in England. The percentage of users recording 28 days of abstinence was compared with a value of 15% estimated for unaided quitting. Correlations were assessed between recorded abstinence for 28 days and well-established abstinence predictors. Results A total of 1170 users met the inclusion criteria. Compared with smokers trying to quit in England, they had higher consumption, and were younger, more likely to be female, and had a non-manual rather than manual occupation. In total, 18.9% (95% CI 16.7-21.1) were recorded as being abstinent from smoking for 28 days or longer. The mean number of logins was 8.5 (SD 9.0). The proportion recording abstinence for 28 days or longer was higher in users who were older, in a non-manual occupation, and in those using a smoking cessation medication. Conclusions The recorded 28-day abstinence rates from the mobile app, SF28, suggest that it may help some smokers to stop smoking. Further evaluation by means of a randomized trial appears to be warranted. PMID:25596170

  11. Preliminary Design and Evaluation of an Airfoil with Continuous Trailing-Edge Flap

    NASA Technical Reports Server (NTRS)

    Shen, Jinwei; Thornburgh, Robert P.; Kreshock, Andrew R.; Wilbur, Matthew L.; Liu, Yi

    2012-01-01

    This paper presents the preliminary design and evaluation of an airfoil with active continuous trailing-edge flap (CTEF) as a potential rotorcraft active control device. The development of structural cross-section models of a continuous trailing-edge flap airfoil is described. The CTEF deformations with MFC actuation are predicted by NASTRAN and UM/VABS analyses. Good agreement is shown between the predictions from the two analyses. Approximately two degrees of CTEF deflection, defined as the rotation angle of the trailing edge, is achieved with the baseline MFC-PZT bender. The 2D aerodynamic characteristics of the continuous trailing-edge flap are evaluated using a CFD analysis. The aerodynamic efficiency of a continuous trailing-edge flap is compared to that of a conventional discrete trailing-edge flap (DTEF). It is found that the aerodynamic characteristics of a CTEF are equivalent to those of a conventional DTEF with the same deflection angle but with a smaller flap chord. A fluid structure interaction procedure is implemented to predict the deflection of the continuous trailingedge flap under aerodynamic pressure. The reductions in CTEF deflection are overall small when aerodynamic pressure is applied: 2.7% reduction is shown with a CTEF deflection angle of two degrees and at angle of attack of six degrees. In addition, newly developed MFC-PMN actuator is found to be a good supplement to MFC-PZT when applied as the bender outside layers. A mixed MFC-PZT and MFC-PMN bender generates 3% more CTEF deformation than an MFC-PZT only bender and 5% more than an MFC-PMN only bender under aerodynamic loads.

  12. Neutron Capture Cross Section of 239Pu

    NASA Astrophysics Data System (ADS)

    Mosby, S.; Arnold, C.; Bredeweg, T. A.; Chyzh, A.; Couture, A.; Henderson, R.; Jandel, M.; Kwan, E.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Wu, C. Y.

    2014-05-01

    The Detector for Advanced Neutron Capture Experiments (DANCE) has been used to measure the 239Pu(n,γ) cross section from 10 eV to the keV region. Three experimental run conditions were used to characterize the prompt fission γ-ray spectrum across the entire energy regime, measure the cross section in the resolved resonance region, and obtain necessary count rate well into the keV region. The preliminary cross sections are in good agreement with current evaluations from 10 eV to 80 keV.

  13. Preliminary time-of-flight neutron diffraction studies of Escherichia coli ABC transport receptor phosphate-binding protein at the Protein Crystallography Station

    PubMed Central

    Sippel, K. H.; Bacik, J.; Quiocho, F. A.; Fisher, S. Z.

    2014-01-01

    Inorganic phosphate is an essential molecule for all known life. Organisms have developed many mechanisms to ensure an adequate supply, even in low-phosphate conditions. In prokaryotes phosphate transport is instigated by the phosphate-binding protein (PBP), the initial receptor for the ATP-binding cassette (ABC) phosphate transporter. In the crystal structure of the PBP–phosphate complex, the phosphate is completely desolvated and sequestered in a deep cleft and is bound by 13 hydrogen bonds: 12 to protein NH and OH donor groups and one to a carboxylate acceptor group. The carboxylate plays a key recognition role by accepting a phosphate hydrogen. PBP phosphate affinity is relatively consistent across a broad pH range, indicating the capacity to bind monobasic (H2PO4 −) and dibasic (HPO4 2−) phosphate; however, the mechanism by which it might accommodate the second hydrogen of monobasic phosphate is unclear. To answer this question, neutron diffraction studies were initiated. Large single crystals with a volume of 8 mm3 were grown and subjected to hydrogen/deuterium exchange. A 2.5 Å resolution data set was collected on the Protein Crystallography Station at the Los Alamos Neutron Science Center. Initial refinement of the neutron data shows significant nuclear density, and refinement is ongoing. This is the first report of a neutron study from this superfamily. PMID:24915101

  14. Evaluation of B10Plus+* proportional detectors for neutron coincidence counting

    SciTech Connect

    Beddingfield, David H.; Yoon, Seokryung

    2015-07-01

    GE-Reuter-Stokes (GERS) has developed a new line of neutron proportional counters, the B10Plus+* proportional counter. The detector design is intended to serve as a cost-effective alternative to traditional {sup 3}He proportional counters in a variety of applications. The detector is a hybrid design 10B-lined tube optimized with the addition of a small quantity of 3He gas to improve the detector performance and efficiency. As a demonstration of the B10Plus+* detector, GERS has constructed a Uranium Neutron Collar (UNCL) system consisting of B-10Plus+* proportional counters. GERS has designed and built a demonstration UNCL system intended to match the performance of a Type-I UNCL design in Pressurized Water Reactor (PWR) geometry operating in thermal mode. GERS offered their system on loan to the International Atomic Energy Agency (IAEA) Safeguards Division of Technical and Scientific Services for an assessment of the detector technology and the demonstration system. We have characterized the demonstration UNCL system and compared its performance with a traditional Type-I UNCL design in regular use by the IAEA. This paper summarizes our findings and observations during the characterization and testing activity. (authors)

  15. Neutron Dosimetry on the Full-Core First Generation VVER-440 Aimed at Reactor Support Structure Load Evaluation

    NASA Astrophysics Data System (ADS)

    Borodkin, P.; Borodkin, G.; Khrennikov, N.; Konheiser, J.; Noack, K.

    2009-08-01

    Reactor support structures (RSS), especially the ferritic steel wall of the water tank, of first-generation VVER-440 are non-restorable reactor equipment, and their lifetime may restrict plant-life. All operated Russian first generation VVER-440 have a reduced core with dummy assemblies except Unit 4 of Novovoronezh nuclear power plant (NPP). In comparison with other reactors, the full-core loading scheme of this reactor provides the highest neutron fluence on the reactor pressure vessel (RPV) and RSS accumulated over design service-life and its prolongation. The radiation load parameters on the RPV and RSS that have resulted from this core loading scheme should be evaluated by means of precise calculations and validated by ex-vessel neutron dosimetry to provide the reliable assessment of embrittlement parameters of these reactor components. The results of different types of calculations and their comparison with measured data have been analyzed in this paper. The calculational analysis of RSS fluence rate variation in dependence on the core loading scheme, including the standard and low leakage core as well as the introduction of dummy assemblies, is presented in this paper.

  16. An Evaluation of the Rheumatology Coverage of Index Medicus. A Preliminary Report

    ERIC Educational Resources Information Center

    Thorpe, Peter

    1972-01-01

    A preliminary investigation which revealed the omission of four full length articles on rheumatology from Index Medicus'' is reported upon. Further investigations are in progress and will be reported at a later date. (Author/SJ)

  17. PRELIMINARY EVALUATION OF DWPF IMPACTS OF BORIC ACID USE IN CESIUM STRIP FOR SWPF AND MCU

    SciTech Connect

    Stone, M.

    2010-09-28

    A new solvent system is being evaluated for use in the Modular Caustic-Side Solvent Extraction Unit (MCU) and in the Salt Waste Processing Facility (SWPF). The new system includes the option to replace the current dilute nitric acid strip solution with boric acid. To support this effort, the impact of using 0.01M, 0.1M, 0.25M and 0.5M boric acid in place of 0.001M nitric acid was evaluated for impacts on the DWPF facility. The evaluation only covered the impacts of boric acid in the strip effluent and does not address the other changes in solvents (i.e., the new extractant, called MaxCalix, or the new suppressor, guanidine). Boric acid additions may lead to increased hydrogen generation during the SRAT and SME cycles as well as change the rheological properties of the feed. The boron in the strip effluent will impact glass composition and could require each SME batch to be trimmed with boric acid to account for any changes in the boron from strip effluent additions. Addition of boron with the strip effluent will require changes in the frit composition and could lead to changes in melt behavior. The severity of the impacts from the boric acid additions is dependent on the amount of boric acid added by the strip effluent. The use of 0.1M or higher concentrations of boric acid in the strip effluent was found to significantly impact DWPF operations while the impact of 0.01M boric acid is expected to be relatively minor. Experimental testing is required to resolve the issues identified during the preliminary evaluation. The issues to be addressed by the testing are: (1) Impact on SRAT acid addition and hydrogen generation; (2) Impact on melter feed rheology; (3) Impact on glass composition control; (4) Impact on frit production; and (5) Impact on melter offgas. A new solvent system is being evaluated for use in the Modular Caustic-Side Solvent Extraction Unit (MCU) and in the Salt Waste Processing Facility (SWPF). The new system includes the option to replace the

  18. Development and Preliminary Evaluation of a Particulate Matter Emission Factor Model for European Motor Vehicles.

    PubMed

    Singh, Rakesh B; Colls, Jeremy J

    2000-10-01

    Although modeling of gaseous emissions from motor vehicles is now quite advanced, prediction of particulate emissions is still at an unsophisticated stage. Emission factors for gasoline vehicles are not reliably available, since gasoline vehicles are not included in the European Union (EU) emission test procedure. Regarding diesel vehicles, emission factors are available for different driving cycles but give little information about change of emissions with speed or engine load. We have developed size-specific speed-dependent emission factors for gasoline and diesel vehicles. Other vehicle-generated emission factors are also considered and the empirical equation for re-entrained road dust is modified to include humidity effects. A methodology is proposed to calculate modal (accelerating, cruising, or idling) emission factors. The emission factors cover particle size ranges up to 10 um, either from published data or from user-defined size distributions. A particulate matter emission factor model (PMFAC), which incorporates virtually all the available information on particulate emissions for European motor vehicles, has been developed. PMFAC calculates the emission factors for five particle size ranges [i.e., total suspended particulates (TSP), PM10, PM5, PM25, and PM1] from both vehicle exhaust and nonexhaust emissions, such as tire wear, brake wear, and re-entrained road dust. The model can be used for an unlimited number of roads and lanes, and to calculate emission factors near an intersection in user-defined elements of the lane. PMFAC can be used for a variety of fleet structures. Hot emission factors at the user-defined speed can be calculated for individual vehicles, along with relative cold-to-hot emission factors. The model accounts for the proportions of distance driven with cold engines as a function of ambient temperature and road type (i.e., urban, rural, or motorway). A preliminary evaluation of PMFAC with an available dispersion model to predict the

  19. Development and preliminary evaluation of a particulate matter emission factor model for European motor vehicles.

    PubMed

    Singh, R B; Colls, J J

    2000-10-01

    Although modeling of gaseous emissions from motor vehicles is now quite advanced, prediction of particulate emissions is still at an unsophisticated stage. Emission factors for gasoline vehicles are not reliably available, since gasoline vehicles are not included in the European Union (EU) emission test procedure. Regarding diesel vehicles, emission factors are available for different driving cycles but give little information about change of emissions with speed or engine load. We have developed size-specific speed-dependent emission factors for gasoline and diesel vehicles. Other vehicle-generated emission factors are also considered and the empirical equation for re-entrained road dust is modified to include humidity effects. A methodology is proposed to calculate modal (accelerating, cruising, or idling) emission factors. The emission factors cover particle size ranges up to 10 microns, either from published data or from user-defined size distributions. A particulate matter emission factor model (PMFAC), which incorporates virtually all the available information on particulate emissions for European motor vehicles, has been developed. PMFAC calculates the emission factors for five particle size ranges [i.e., total suspended particulates (TSP), PM10, PM5, PM2.5, and PM1] from both vehicle exhaust and nonexhaust emissions, such as tire wear, brake wear, and re-entrained road dust. The model can be used for an unlimited number of roads and lanes, and to calculate emission factors near an intersection in user-defined elements of the lane. PMFAC can be used for a variety of fleet structures. Hot emission factors at the user-defined speed can be calculated for individual vehicles, along with relative cold-to-hot emission factors. The model accounts for the proportions of distance driven with cold engines as a function of ambient temperature and road type (i.e., urban, rural, or motorway). A preliminary evaluation of PMFAC with an available dispersion model to predict

  20. Preliminary Evaluation of the Control of Microbial Fouling by Laboratory and Pilot-Scale Air-Stripping Columns

    DTIC Science & Technology

    1985-03-01

    AD-A186 558 TECHNICAL REPORT AD NATICK/TR-87/039 PRELIMINARY EVALUATION OF THE CONTROL OF MICROBIAL FOULING BY LABORATORY AND PILOT-SCALE AIR ...Scale Air -Stripping Columns. 12. PERSONAL AUTHOR(S) Darrell Seekins, Morris Rogers 13a. TYPE OF REPORT 13b. TIME COVERED 114. DATE OF REPORT (Year...TERMS (Continue on reverse if necessary and identify by block number) FIELD GROUP TSUB-GROUP Air -Stripping Microbial Fouling Aeration Biogrowth Control

  1. Preliminary Evaluations of Polymer-based Lithium Battery Electrolytes Under Development for the Polymer Electrolyte Rechargeable Systems Program

    NASA Technical Reports Server (NTRS)

    Manzo, Michelle A.; Bennett, William R.

    2003-01-01

    A component screening facility has been established at The NASA Glenn Research Center (GRC) to evaluate candidate materials for next generation, lithium-based, polymer electrolyte batteries for aerospace applications. Procedures have been implemented to provide standardized measurements of critical electrolyte properties. These include ionic conductivity, electronic resistivity, electrochemical stability window, cation transference number, salt diffusion coefficient and lithium plating efficiency. Preliminary results for poly(ethy1ene oxide)-based polymer electrolyte and commercial liquid electrolyte are presented.

  2. Evaluation of Liver Stiffness After Radioembolization by Real-Time ShearWave™ Elastography: Preliminary Study

    SciTech Connect

    Bas, Ahmet; Samanci, Cesur; Gulsen, Fatih Cantasdemir, Murat; Kabasakal, Levent; Kantarci, Fatih; Numan, Furuzan

    2015-08-15

    PurposeTo evaluate the effect of ShearWave™ elastography (SWE) for the assessment of liver fibrosis after radioembolization (RE) in patients with liver malignancies.Materials and MethodsWe prospectively examined the effects of SWE before and after RE in 17 adult patients, from June 2012 to September 2013. All patients underwent SWE within 1 month before and 3 months (96.3 ± 22.9 days) after RE. Measurements were taken in segments III, IV, V, and VI (lateral/medial left lobe and anterior/posterior right lobe, respectively). Liver stiffness was studied in the 39 treated segments.ResultsThe mean stiffness of liver tissue according to the pre-RE SWE measurements was not different from the post-RE SWE measurements in the segments that did not undergo RE. Conversely, segments treated with RE were significantly stiffer according to the post-RE SWE measurements (mean SWE 17.4 kPa) than according to the baseline measurements (7.0 kPa) (p < 0.001). Patients with hepatocellular carcinoma and preexisting infection with hepatitis B and C viruses had higher pre-embolization stiffness, and the post-embolization stiffness of the treated segments in these patients was higher than that in the remainder of the study population.ConclusionThese data suggest that SWE measurements of liver stiffness increase as early as the third month after RE. SWE could be used as a noninvasive complementary imaging method for preliminary assessment of liver fibrosis before and after RE.

  3. Fast and simple method for Goss texture evaluation by neutron diffraction

    NASA Astrophysics Data System (ADS)

    Kucerakova, M.; Kolařík, K.; Čapek, J.; Vratislav, S.; Kalvoda, L.

    2016-09-01

    Requirement of low power losses is one of the crucial demands laid on properties of electric steel sheets used in construction of various magnetic circuits. For cold-rolled grain- oriented (CRGO) Fe-3%Si sheets used in majority of power distribution transformers, the Goss texture {110}<001> is known to provide the best utility properties (low power loses, high magnetic permeability). Due to the coarse grain size of CRGO steel, neutron diffraction (ND) is dominantly used to characterize the sheets' texture in order to achieve statistically significant data. In this paper, we present a fast and simple method for characterization of Goss texture perfection level in CRGO steel sheets based on monochromatic ND. The method is tested on 8 samples differing in fabrication technology and magnetic properties. Satisfactory performance of the method and its suitability for a detail texture analyses is tested by juxtaposition of the obtained textural and the magnetic characteristics measured by Barkhausen method.

  4. Evaluation of the need for emergency heat exchangers for long term emergency cooling of the Advanced Neutron Source Reactor

    SciTech Connect

    Khayat, M.I.; Anderson, J.L.; Battle, R.E.; March-Leuba, J.

    1994-05-01

    This report summarizes the work performed to evaluate the heat transferred to the light water pools from the primary piping system for the Advanced Neutron Source reactor (ANSR) conceptual design. It has been determined that the ANSR primary piping system will remove sufficient heat from the primary coolant system to the pools for certain design basis event accidents without the emergency heat exchangers if the design parameters, such as pool volumes and pipe sizes (length and surface area), are selected appropriately. Based on this analysis, the emergency heat exchangers might be removed, and their function can be performed by the primary piping passing through the light water pools described in the conceptual design report. This study also shows that connecting the pipe chase pool and the heat exchanger pools improve performance for ANSR emergency heat removal.

  5. Evaluation of the Role of Probiotics in Endodontic Treatment: A Preliminary Study

    PubMed Central

    Bohora, Aarti; Kokate, Sharad

    2017-01-01

    Aims and Objectives: The principal goal of endodontics is the prevention of periapical infection. Acute and chronic apical periodontitis occur due to the persistence of pathogenic microorganisms such as Enterococcus faecalis and Candida albicans harboring the root canal systems of the teeth. The concept of the use of probiotics in addressing endodontic disease is new and has not been studied adequately. On the basis of the success of probiotics in periodontal treatment, this preliminary work was performed (a) to evaluate the antibacterial efficacy of probiotics against common endodontic pathogens, i.e. E. faecalis and C. albicans, and (b) to evaluate the potential use of probiotic therapy as an additive in endodontic treatment procedures. Materials and Methods: Two commercial probiotics were selected and evaluated based upon the numbers and concentration of organisms. Pathogenic test organisms were C. albicans (ATCC 10231) and E. faecalis (ATCC 29212). Phase 1 of the study was conducted by agar cup method test to evaluate the antibacterial activity of the selected probiotics against E. faecalis and C. albicans by measuring zones of inhibition (ZOI) in mm. Microorganisms from probiotic samples were isolated following manufacturer's instructions. Pathogenic organisms were set to a 0.1 McFarland standard challenge. Circular wells of 8 mm diameter were punched in each of the poured plates. Appropriately diluted test samples were added to the above-punched wells. The volume of the solution added to each well was 100 μl. The plates were incubated in an upright position at 37°C for 24 hours under aerobic conditions. Post incubation, ZOI was measured (mm). Phase 2 was conducted by mixing 9 ml of 30% poloxamer 407 and de Man, Rogosa and Sharpe (MRS) broth in a test tube with 500 μl of either E. faecalis or C. albicans set at an optical density (OD) of 0.252, together with 500 μl of test probiotic strain, set at a respective OD. Samples were then incubated at 37°C for

  6. Evaluated 182,183,184,186W Neutron Cross Sections and Covariances in the Resolved Resonance Region

    SciTech Connect

    Pigni, Marco T; Leal, Luiz C

    2015-01-01

    Oak Ridge National Laboratory (ORNL) has recently completed the resonance parameter evaluation of four tungsten isotopes, i.e., 182,183,184,186W, in the neutron energy range of thermal up to several keV. This nuclear data work was performed with support from the US Nuclear Criticality Safety Program (NCSP) in an effort to provide improved tungsten cross section and covariance data for criticality safety analyses. The evaluation methodology uses the Reich-Moore approximation of the R-matrix formalism of the code SAMMY to fit high-resolution measurements performed in 2010 and 2012 at the Geel linear accelerator facility (GELINA), as well as other experimental data sets on natural tungsten available in the EXFOR library. In the analyzed energy range, this work nearly doubles the resolved resonance region (RRR) present in the latest US nuclear data library ENDF/B-VII.1. In view of the interest in tungsten for distinct types of nuclear applications and the relatively homogeneous distribution of the isotopic tungsten—namely, 182W(26.5%), 183W(14.31%), 184W(30.64%), and 186W(28.43%) - the completion of these four evaluations represents a significant contribution to the improvement of the ENDF library. This paper presents an overview of the evaluated resonance parameters and related covariances for total and capture cross sections on the four tungsten isotopes.

  7. A preliminary evaluation of alternatives for disposal of INEL low-level waste and low-level mixed waste

    SciTech Connect

    Smith, T.H.; Roesener, W.S.; Jorgenson-Waters, M.J.

    1993-07-01

    The Mixed and Low-Level Waste Disposal Facility (MLLWDF) project was established in 1992 by the US Department of Energy Idaho Operations Office to provide enhanced disposal capabilities for Idaho National Engineering Laboratory (INEL) low-level mixed waste and low-level waste. This Preliminary Evaluation of Alternatives for Disposal of INEL Low-Level Waste and Low-Level Mixed Waste identifies and evaluates-on a preliminary, overview basis-the alternatives for disposal of that waste. Five disposal alternatives, ranging from of no-action`` to constructing and operating the MLLWDF, are identified and evaluated. Several subalternatives are formulated within the MLLWDF alternative. The subalternatives involve various disposal technologies as well as various scenarios related to the waste volumes and waste forms to be received for disposal. The evaluations include qualitative comparisons of the projected isolation performance for each alternative, and facility, health and safety, environmental, institutional, schedule, and rough order-of-magnitude life-cycle cost comparisons. The performance of each alternative is evaluated against lists of ``musts`` and ``wants.`` Also included is a discussion of other key considerations for decisionmaking. The analysis of results indicated further study is necessary to obtain the best estimate of long-term future waste volume and characteristics from the INEL Environmental Restoration activities and the expanded INEL Decontamination and Decommissioning Program.

  8. Evaluation of radiochemical neutron activation analysis methods for determination of arsenic in biological materials.

    PubMed

    Paul, Rick L

    2011-01-01

    Radiochemical neutron activation analysis (RNAA) with retention on hydrated manganese dioxide (HMD) has played a key role in the certification of As in biological materials at NIST. Although this method provides very high and reproducible yields and detection limits at low microgram/kilogram levels, counting geometry uncertainties may arise from unequal distribution of As in the HMD, and arsenic detection limits may not be optimal due to significant retention of other elements. An alternate RNAA procedure with separation of arsenic by solvent extraction has been investigated. After digestion of samples in nitric and perchloric acids, As(III) is extracted from 2 M sulfuric acid solution into a solution of zinc diethyldithiocarbamate in chloroform. Counting of (76)As allows quantitation of arsenic. Addition of an (77)As tracer solution prior to dissolution allows correction for chemical yield and counting geometries, further improving reproducibility. The HMD and solvent extraction procedures for arsenic were compared through analysis of SRMs 1577c (bovine liver), 1547 (peach leaves), and 1575a (pine needles). Both methods gave As results in agreement with certified values with comparable reproducibility. However, the solvent extraction method yields a factor of 3 improvement in detection limits and is less time-consuming than the HMD method. The new method shows great promise for use in As certification in reference materials.

  9. Evaluation of precision and accuracy of selenium measurements in biological materials using neutron activation analysis

    SciTech Connect

    Greenberg, R.R.

    1988-01-01

    In recent years, the accurate determination of selenium in biological materials has become increasingly important in view of the essential nature of this element for human nutrition and its possible role as a protective agent against cancer. Unfortunately, the accurate determination of selenium in biological materials is often difficult for most analytical techniques for a variety of reasons, including interferences, complicated selenium chemistry due to the presence of this element in multiple oxidation states and in a variety of different organic species, stability and resistance to destruction of some of these organo-selenium species during acid dissolution, volatility of some selenium compounds, and potential for contamination. Neutron activation analysis (NAA) can be one of the best analytical techniques for selenium determinations in biological materials for a number of reasons. Currently, precision at the 1% level (1s) and overall accuracy at the 1 to 2% level (95% confidence interval) can be attained at the U.S. National Bureau of Standards (NBS) for selenium determinations in biological materials when counting statistics are not limiting (using the {sup 75}Se isotope). An example of this level of precision and accuracy is summarized. Achieving this level of accuracy, however, requires strict attention to all sources of systematic error. Precise and accurate results can also be obtained after radiochemical separations.

  10. Evaluation of vectorized Monte Carlo algorithms on GPUs for a neutron Eigenvalue problem

    SciTech Connect

    Du, X.; Liu, T.; Ji, W.; Xu, X. G.; Brown, F. B.

    2013-07-01

    Conventional Monte Carlo (MC) methods for radiation transport computations are 'history-based', which means that one particle history at a time is tracked. Simulations based on such methods suffer from thread divergence on the graphics processing unit (GPU), which severely affects the performance of GPUs. To circumvent this limitation, event-based vectorized MC algorithms can be utilized. A versatile software test-bed, called ARCHER - Accelerated Radiation-transport Computations in Heterogeneous Environments - was used for this study. ARCHER facilitates the development and testing of a MC code based on the vectorized MC algorithm implemented on GPUs by using NVIDIA's Compute Unified Device Architecture (CUDA). The ARCHER{sub GPU} code was designed to solve a neutron eigenvalue problem and was tested on a NVIDIA Tesla M2090 Fermi card. We found that although the vectorized MC method significantly reduces the occurrence of divergent branching and enhances the warp execution efficiency, the overall simulation speed is ten times slower than the conventional history-based MC method on GPUs. By analyzing detailed GPU profiling information from ARCHER, we discovered that the main reason was the large amount of global memory transactions, causing severe memory access latency. Several possible solutions to alleviate the memory latency issue are discussed. (authors)

  11. Eco-Doppler evaluation of intestinal peristalsis in normal and in some pathological conditions: preliminary data.

    PubMed

    La Bella, A; Gimondo, P; Camboni, M

    1993-01-01

    Duplex-Doppler sonography could be employed in the quantitative investigation of intestinal motility. Preliminary data indicate reproductivity of the method in normal subjects and possible clinical applications in some pathological conditions affecting intestinal transit. Particularly, the possibility to discriminate between segments at different peristaltic activity seems to be very useful in intestinal obstruction. Further studies are necessary to validate this method.

  12. Developing Parenting Skills through Health Visitors: Preliminary Results from an Evaluation Study.

    ERIC Educational Resources Information Center

    Stevenson, Jim

    Preliminary results of a study of the extent to which training health visitors in behavior modification techniques improves the effectiveness of their work with families of young children are presented. A total of 14 health visitors were recruited and assigned to training and delay-of-training groups. Selected from case loads, participating…

  13. Satellite Power Systems (SPS): Concept development and evaluation program: Preliminary assessment

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A preliminary assessment of a potential Satellite Power System (SPS) is provided. The assessment includes discussion of technical and economic feasibility; the effects of microwave power transmission beams on biological, ecological, and electromagnetic systems; the impact of SPS construction, deployment, and operations on the biosphere and on society; and the merits of SPS compared to other future energy alternatives.

  14. A PRELIMINARY METHODOLOGY FOR EVALUATING THE COST-EFFECTIVENESS OF ALTERNATIVE INDOOR AIR QUALITY APPROACHES

    EPA Science Inventory

    The report defines a simplified methodology that can be used by indoor air quality (IAQ) diagnosticians, architects/engineers, building owners/operators, and the scientific community for preliminary comparison of the cost-effectiveness of alternative IAQ control measures for any ...

  15. Evaluation of equivalent dose from neutrons and activation products from a 15-MV X-ray LINAC

    PubMed Central

    Israngkul-Na-Ayuthaya, Isra; Suriyapee, Sivalee; Pengvanich, Phongpheath

    2015-01-01

    A high-energy photon beam that is more than 10 MV can produce neutron contamination. Neutrons are generated by the [γ,n] reactions with a high-Z target material. The equivalent neutron dose and gamma dose from activation products have been estimated in a LINAC equipped with a 15-MV photon beam. A Monte Carlo simulation code was employed for neutron and photon dosimetry due to mixed beam. The neutron dose was also experimentally measured using the Optically Stimulated Luminescence (OSL) under various conditions to compare with the simulation. The activation products were measured by gamma spectrometer system. The average neutron energy was calculated to be 0.25 MeV. The equivalent neutron dose at the isocenter obtained from OSL measurement and MC calculation was 5.39 and 3.44 mSv/Gy, respectively. A gamma dose rate of 4.14 µSv/h was observed as a result of activations by neutron inside the treatment machine. The gamma spectrum analysis showed 28Al, 24Na, 54Mn and 60Co. The results confirm that neutrons and gamma rays are generated, and gamma rays remain inside the treatment room after the termination of X-ray irradiation. The source of neutrons is the product of the [γ,n] reactions in the machine head, whereas gamma rays are produced from the [n,γ] reactions (i.e. neutron activation) with materials inside the treatment room. The most activated nuclide is 28Al, which has a half life of 2.245 min. In practice, it is recommended that staff should wait for a few minutes (several 28Al half-lives) before entering the treatment room after the treatment finishes to minimize the dose received. PMID:26265661

  16. Evaluation of equivalent dose from neutrons and activation products from a 15-MV X-ray LINAC.

    PubMed

    Israngkul-Na-Ayuthaya, Isra; Suriyapee, Sivalee; Pengvanich, Phongpheath

    2015-11-01

    A high-energy photon beam that is more than 10 MV can produce neutron contamination. Neutrons are generated by the [γ,n] reactions with a high-Z target material. The equivalent neutron dose and gamma dose from activation products have been estimated in a LINAC equipped with a 15-MV photon beam. A Monte Carlo simulation code was employed for neutron and photon dosimetry due to mixed beam. The neutron dose was also experimentally measured using the Optically Stimulated Luminescence (OSL) under various conditions to compare with the simulation. The activation products were measured by gamma spectrometer system. The average neutron energy was calculated to be 0.25 MeV. The equivalent neutron dose at the isocenter obtained from OSL measurement and MC calculation was 5.39 and 3.44 mSv/Gy, respectively. A gamma dose rate of 4.14 µSv/h was observed as a result of activations by neutron inside the treatment machine. The gamma spectrum analysis showed (28)Al, (24)Na, (54)Mn and (60)Co. The results confirm that neutrons and gamma rays are generated, and gamma rays remain inside the treatment room after the termination of X-ray irradiation. The source of neutrons is the product of the [γ,n] reactions in the machine head, whereas gamma rays are produced from the [n,γ] reactions (i.e. neutron activation) with materials inside the treatment room. The most activated nuclide is (28)Al, which has a half life of 2.245 min. In practice, it is recommended that staff should wait for a few minutes (several (28)Al half-lives) before entering the treatment room after the treatment finishes to minimize the dose received.

  17. Evaluation of Aluminum-Boron Carbide Neutron Absorbing Materials for Interim Storage of Used Nuclear Fuel

    SciTech Connect

    Wang, Lumin; Wierschke, Jonathan Brett

    2015-04-08

    The objective of this work was to understand the corrosion behavior of Boral® and Bortec® neutron absorbers over long-term deployment in a used nuclear fuel dry cask storage environment. Corrosion effects were accelerated by flowing humidified argon through an autoclave at temperatures up to 570°C. Test results show little corrosion of the aluminum matrix but that boron is leaching out of the samples. Initial tests performed at 400 and 570°C were hampered by reduced flow caused by the rapid build-up of solid deposits in the outlet lines. Analysis of the deposits by XRD shows that the deposits are comprised of boron trioxide and sassolite (H3BO3). The collection of boron- containing compounds in the outlet lines indicated that boron was being released from the samples. Observation of the exposed samples using SEM and optical microscopy show the growth of new phases in the samples. These phases were most prominent in Bortec® samples exposed at 570°C. Samples of Boral® exposed at 570°C showed minimal new phase formation but showed nearly the complete loss of boron carbide particles. Boron carbide loss was also significant in Boral samples at 400°C. However, at 400°C phases similar to those found in Bortec® were observed. The rapid loss of the boron carbide particles in the Boral® is suspected to inhibit the formation of the new secondary phases. However, Material samples in an actual dry cask environment would be exposed to temperatures closer to 300°C and less water than the lowest test. The results from this study conclude that at the temperature and humidity levels present in a dry cask environment, corrosion and boron leaching will have no effect on the performance of Boral® and Bortec® to maintain criticality control.

  18. Preliminary results of UCN τ

    NASA Astrophysics Data System (ADS)

    Pattie, Robert; UCNtau Collaboration

    2017-01-01

    There is currently a 4 σ discrepancy between measurements of the neutron lifetime performed using cold neutron beams and those performed with ultracold neutron (UCN) storage vessels. The UCN τ experiment uses an asymmetric magneto-gravitational UCN trap with in situ counting of surviving neutrons to measure the neutron lifetime. This design eliminates a major systematic of previous bottle experiments related to the loss of UCN on material trap walls and with unloading neutrons from the storage vessel. A new in situ detection system was used in the 2015-2016 run that was able to measure the population of surviving UCN at different heights in the trap, providing important information on spectral evolution. Understanding the behavior of quasi-bound UCN in a bottle experiment is essential to achieving a subsecond precision measurement of τn. We will present the preliminary results from the 2015-2016 data set and an update on the UCN τ experiment.

  19. Evaluation of the thermal-neutron constants for /sup 233/U, /sup 235/U, /sup 239/Pu and /sup 241/Pu

    SciTech Connect

    Stehn, J.R.; Divadeenam, M.; Holden, N.E.

    1982-01-01

    A consistent set of best values of the 2200 meter/second neutron cross sections, Westcott g-factors, and fission neutron yields for /sup 233/U, /sup 235/U, /sup 239/Pu and /sup 241/Pu are presented. A least squares fitting program, LSF, is used to obtain the best fit and to estimate the sensitivity of these fissile parameters to the quoted uncertainties in experimental data. The half-lives of the uranium and plutonium nuclides have been evaluated and these have been used to reassess the significant experimental data. The latest revision of the spontaneous fission neutron yield anti nu, of /sup 252/Cf and the foil thickness corrections to the fission neutron yield ratios of fissile nuclei to /sup 252/Cf are included. These lead to greater consistency in the data used for anti nu (/sup 252/Cf). Similarly, the /sup 234/U half-life as revised leads to improved consistency in the /sup 235/U fission cross section. Comparison is made with the values from ENDF/B-V and other evaluations.

  20. Quality control and performance evaluation of k0-based neutron activation analysis at the Portuguese research reactor

    NASA Astrophysics Data System (ADS)

    Dung, H. M.; Freitas, M. C.; Blaauw, M.; Almeida, S. M.; Dionisio, I.; Canha, N. H.

    2010-10-01

    The quality control (QC) and performance evaluation for the k0-based neutron activation analysis ( k0-NAA) at the Portuguese research reactor (RPI) has been developed with the intention of using the method to meet the demands of trace element analysis for the applications in environmental, epidemiological and nutritional studies amongst others. The QC and performance evaluation include the following aspects: (1) estimation of the overall/combined standard uncertainty from the primary uncertainty sources; (2) validation of the method using a synthetic multi-element standard (SMELS); and (3) analysis of the certified reference materials from the National Institute of Standards and Technology (USA): NIST-SRM-1633a and NIST-SRM-1648 and the reference material from the International Atomic Energy Agency: IAEA-RM-336, for the purpose of controlling the overall accuracy and precision of the analytical results. The obtained results revealed that the k0-NAA method established at the RPI was fit for the purpose. The overall/combined standard uncertainty was estimated for elements of interest in the intended applications. The laboratory's analytical results as compared to the assigned values with the bias were less than 12% for most elements, except for a few elements which biased within 13-18%. The u-score values for most elements were less than |1.64|, except for Co, La and Ti within |1.64|-|1.96| and Sc, Cr, K and Sb within |1.96|-|2.58|. The NIST-1633a was also analyzed over 14 months for the purpose of evaluating the reproducibility of the method. The quality factors of k0-NAA established at RPI were evaluated, proving that the method meets the requirements of trace element analysis, which is also considering the method's performance for which the k0-NAA affords a specific, rapid and convenient capability for the intended applications.

  1. Atmospheric neutrons

    NASA Technical Reports Server (NTRS)

    Korff, S. A.; Mendell, R. B.; Merker, M.; Light, E. S.; Verschell, H. J.; Sandie, W. S.

    1979-01-01

    Contributions to fast neutron measurements in the atmosphere are outlined. The results of a calculation to determine the production, distribution and final disappearance of atmospheric neutrons over the entire spectrum are presented. An attempt is made to answer questions that relate to processes such as neutron escape from the atmosphere and C-14 production. In addition, since variations of secondary neutrons can be related to variations in the primary radiation, comment on the modulation of both radiation components is made.

  2. Evaluation of Hylife-II and Sombrero using 175- and 566- group neutron transport and activation cross sections

    SciTech Connect

    Cullen, D; Latkowski, J; Sanz, J

    1999-06-18

    Recent modifications to the TART Monte Carlo neutron and photon transport code enable calculation of 566-group neutron spectra. This expanded group structure represents a significant improvement over the 50- and 175-group structures that have been previously available. To support use of this new capability, neutron activation cross section libraries have been created in the 175- and 566-group structures starting from the FENDL/A-2.0 pointwise data. Neutron spectra have been calculated for the first walls of the HYLIFE-II and SOMBRERO inertial fusion energy power plant designs and have been used in subsequent neutron activation calculations. The results obtained using the two different group structures are compared to each other as well as to those obtained using a 175-group version of the EAF3.1 activation cross section library.

  3. Preliminary volcanic hazards evaluation for Los Alamos National Laboratory Facilities and Operations : current state of knowledge and proposed path forward

    SciTech Connect

    Keating, Gordon N.; Schultz-Fellenz, Emily S.; Miller, Elizabeth D.

    2010-09-01

    The integration of available information on the volcanic history of the region surrounding Los Alamos National Laboratory indicates that the Laboratory is at risk from volcanic hazards. Volcanism in the vicinity of the Laboratory is unlikely within the lifetime of the facility (ca. 50–100 years) but cannot be ruled out. This evaluation provides a preliminary estimate of recurrence rates for volcanic activity. If further assessment of the hazard is deemed beneficial to reduce risk uncertainty, the next step would be to convene a formal probabilistic volcanic hazards assessment.

  4. Synthesis and preliminary biological evaluation of a compound library of triazolylcyclitols.

    PubMed

    Carrau, Gonzalo; Drewes, Carine C; Shimada, Ana Lúcia B; Bertucci, Ana; Farsky, Sandra H P; Stefani, Helio A; Gonzalez, David

    2013-07-15

    A small library of compounds was prepared by a combination of toluene dioxygenase (TDO)-catalyzed enzymatic dihydroxylation and copper(I)-catalyzed Hüisgen cycloaddition. Some compounds were obtained by coupling an alkyne and a conduritol derivative, while more complex structures were obtained by a double Hüisgen reaction of a dialkyne and two molecules of the cyclitol. The compounds were fully characterized and subjected to preliminary biological screening.

  5. Neutron dosimetry

    DOEpatents

    Quinby, Thomas C.

    1976-07-27

    A method of measuring neutron radiation within a nuclear reactor is provided. A sintered oxide wire is disposed within the reactor and exposed to neutron radiation. The induced radioactivity is measured to provide an indication of the neutron energy and flux within the reactor.

  6. Neutron guide

    DOEpatents

    Greene, Geoffrey L.

    1999-01-01

    A neutron guide in which lengths of cylindrical glass tubing have rectangular glass plates properly dimensioned to allow insertion into the cylindrical glass tubing so that a sealed geometrically precise polygonal cross-section is formed in the cylindrical glass tubing. The neutron guide provides easier alignment between adjacent sections than do the neutron guides of the prior art.

  7. The enigmatic Mongol-Okhotsk Belt in NE Mongolia - a preliminary evaluation of the geodynamic development

    NASA Astrophysics Data System (ADS)

    Denise, Bussien; Nergui, Martin-Gombojav; Wilfried, Winkler; Quadt Albrecht, Von

    2010-05-01

    The Mongol-Okhotsk Belt (MOB) extends from Central Mongolia across eastern Siberia towards the Okhotsk Sea in the northwestern Pacific. The belt formed in a late stage of Jurassic orogeny in the composite Central Asian Orogenic Belt by the consumption of the Mongol-Okhotsk ocean (MOO). The Late Paleozoic-Mesozoic sediments associated with the belt in Mongolia are investigated in order to evaluate the timing and mode of ocean formation, the subduction and the collision of the framing margins. We apply an advanced provenance analysis including (1) heavy mineral and sandstone framework grain analysis and (2) U/Pb laser ablation ICPMS dating, trace element, and Hf isotope analysis of detrital zircons. We differentiate three tectono-stratigraphic units: (1) the Adaatsag and Doschgol terranes, which are supposed to represent the suture zone, (2) the Hangai-Hentei basin to the northwest of the suture, and (3) the Ereendavaa terrane and the Middle Gobi volcanic belt to the southeast. The latter two are concurrent with the northern and southern margins of the former MOO (in modern coordinates) respectively. The northern margin development is documented by ophiolitic accretionary wedge and fore-arc deposits. The southern margin is represented by Devonian-Carboniferous sediments presumably laid down on deformed and metamorphosed Neoproterozoic-Early Paleozoic continental and ophiolitic basement, which initially was accreted against the North Asia Craton (Siberia) by the closure of the Paleoasian ocean in the Ordovician. The available tectono-stratigraphic arguments together with biostratigraphic and radiometric age data suggest that the Mongol-Okhotsk ocean opened in Late Silurian, possibly by back-arc spreading within the Early Paleozoic collage due to northward subduction of the Paleotethys/Paleopacific ocean under the accreted Mongolian margin. The syn-sedimentary U/Pb detrital zircon age patterns and Hf isotopic values (epsilon Hf +6 - +7 in Devonian and Permo

  8. Use of a TLD-based multisphere spectrometry system to measure the neutron spectra around a not-self-shielded PET cyclotron: Preliminary results.

    PubMed

    Guimarães, A M; Lacerda, M A S; Santos, J A L; Maletta, P G M; Rodrigues, S L M; Andrade, R S; Vilela, E C; da Silva, T A

    2012-12-01

    In the present work, we utilized the BSS system with TLD-600 and TLD-700 to measure the neutron spectra around the GE-PETtrace 8 cyclotron of the Development Centre of Nuclear Technology (CDTN/CNEN) in Belo Horizonte, Brazil. The cyclotron is capable of accelerating protons up to 16.5 MeV, to production of fluorine-18. Four points inside the bunker of the cyclotron were studied. Two points in front of the primary radiation beam and other two opposed to the primary radiation beam. The measurements were unfolded with the BUMS and the NSDUAZ computer codes. The dosimetric quantities obtained were in agreement with the other published data and were coherent with the expected from theoretical estimates obtained from source term informed by the manufacturer of the cyclotron.

  9. Synthesis and evaluation of thymidine kinase 1-targeting carboranyl pyrimidine nucleoside analogs for boron neutron capture therapy of cancer.

    PubMed

    Agarwal, Hitesh K; Khalil, Ahmed; Ishita, Keisuke; Yang, Weilian; Nakkula, Robin J; Wu, Lai-Chu; Ali, Tehane; Tiwari, Rohit; Byun, Youngjoo; Barth, Rolf F; Tjarks, Werner

    2015-07-15

    A library of sixteen 2nd generation amino- and amido-substituted carboranyl pyrimidine nucleoside analogs, designed as substrates and inhibitors of thymidine kinase 1 (TK1) for potential use in boron neutron capture therapy (BNCT) of cancer, was synthesized and evaluated in enzyme kinetic-, enzyme inhibition-, metabolomic-, and biodistribution studies. One of these 2nd generation carboranyl pyrimidine nucleoside analogs (YB18A [3]), having an amino group directly attached to a meta-carborane cage tethered via ethylene spacer to the 3-position of thymidine, was approximately 3-4 times superior as a substrate and inhibitor of hTK1 than N5-2OH (2), a 1st generation carboranyl pyrimidine nucleoside analog. Both 2 and 3 appeared to be 5'-monophosphorylated in TK1(+) RG2 cells, both in vitro and in vivo. Biodistribution studies in rats bearing intracerebral RG2 glioma resulted in selective tumor uptake of 3 with an intratumoral concentration that was approximately 4 times higher than that of 2. The obtained results significantly advance the understanding of the binding interactions between TK1 and carboranyl pyrimidine nucleoside analogs and will profoundly impact future design strategies for these agents.

  10. Neutron activation and other analytical data for plutonic rocks from North America and Africa. National Uranium Resource Evaluation

    SciTech Connect

    Price, V.; Fay, W.M.; Cook, J.R.

    1982-09-01

    The objective of this report is to retrieve the elements of an analytical study of granites and associated other plutonic rocks which was begun as a part of the U.S. Department of Energy's National Uranium Resource Evaluation (NURE) program. A discussion of the Savannah River Laboratory (SRL) neutron activation analysis system is given so that a user will understand the linmitations of the data. Enough information is given so that an experienced geochemist can clean up the data set to the extent required by any project. The data are generally good as they are presented. It is intended that the data be read from a magnetic tape written to accompany this report. Microfiche tables of the data follow the text. These tables were prepared from data on the tape, and programs which will read the tape are presented in the section THE DATA TAPE. It is our intent to write a later paper which will include a thoroughly scrubbed data set and a technical discussion of results of the study. 1 figure.

  11. Synthesis and evaluation of thymidine kinase 1-targeting carboranyl pyrimidine nucleoside analogues for boron neutron capture therapy of cancer

    PubMed Central

    Agarwal, Hitesh K.; Khalil, Ahmed; Ishita, Keisuke; Yang, Weilian; Nakkula, Robin J.; Wu, Lai-Chu; Ali, Tehane; Tiwari, Rohit; Byun, Youngjoo; Barth, Rolf F.; Tjarks, Werner

    2015-01-01

    A library of sixteen 2nd generation amino- and amido-substituted carboranyl pyrimidine nucleoside analogues, designed as substrates and inhibitors of thymidine kinase 1 (TK1) for potential use in boron neutron capture therapy (BNCT) of cancer, was synthesized and evaluated in enzyme kinetic-, enzyme inhibition-, metabolomic-, and biodistribution studies. One of these 2nd generation carboranyl pyrimidine nucleoside analogues (YB18A [3]), having an amino group directly attached to a meta-carborane cage tethered via ethylene spacer to the 3-position of thymidine, was approximately 3–4 times superior as a substrate and inhibitor of hTK1 than N5-2OH (2), a 1st generation carboranyl pyrimidine nucleoside analogue. Both 2 and 3 appeared to be 5′-monophosphorylated in TK1(+) RG2 cells, both in vitro and in vivo. Biodistribution studies in rats bearing intracerebral RG2 glioma resulted in selective tumor uptake of 3 with an intratumoral concentration that was approximately 4 times higher than that of 2. The obtained results significantly advance the understanding of the binding interactions between TK1 and carboranyl pyrimidine nucleoside analogues and will profoundly impact future design strategies for these agents. PMID:26087030

  12. "m=1" coatings for neutron guides

    NASA Astrophysics Data System (ADS)

    Cooper-Jensen, C. P.; Vorobiev, A.; Klinkby, E.; Kapaklis, V.; Wilkens, H.; Rats, D.; Hjörvarsson, B.; Kirstein, O.; Bentley, P. M.

    2014-07-01

    A substantial fraction of the price for a supermirror neutron guide system is the shielding, which is needed because of the gamma radiation produced as a result of neutron absorption in the supermirror layers. Traditional coatings have been made of nickel-titanium heterostructures, but Ni and Ti also have a fairly high absorption cross section for cold and thermal neutrons. We examine a number of alternatives to Ni as part of a study to reduce the gamma radiation from neutron guides. Materials such as diamond and Be have higher neutron scattering density than Ni, smaller absorption cross section, and when a neutron is absorbed they emit gamma photons with lower energies. We present reflectivity data comparing Ni with Be and preliminary results from diamond coatings showing there use as neutron guide coatings. Calculations show that Be and diamond coatings emit two orders of magnitude fewer gamma photons compared to Ni, mainly because of the lower absorption cross section.

  13. Evaluating a Contribution of the Knock-on Deuterons to the Neutron Yield in the Experiments with Weakly Collisional Plasma Jets (Part 1)

    SciTech Connect

    Ryutov, D. D.

    2015-12-01

    Laser-generated interpenetrating plasma jets are widely used in the studies of collisionless interaction of counter-streaming plasmas in conjunction with possible formation of collisionless shocks. In a number of experiments of this type the plasma is formed on plastic targets made of CH or CD. The study of the DD neutron production from the interaction between two CD jets on the one hand and between a CD jet and a CH jet could serve as a qualitative indicator of the collisionless shock formation. The purpose of this memo is a discussion of the effect of collisions on the neutron generation in the interpenetrating CH and CD jets. First, the kinematics of the large-deflection collisions of the deuterons and carbon are discussed. Then the scattering angles are related with the corresponding Rutherford cross-section. After that expression for the number of the backscattered deuterons is provided, and their contribution to the neutron yield is evaluated. The results may be of some significance to the kinetic codes benchmarking and developing the neutron diagnostic.

  14. Evaluation of the /sup 252/Cf-source-driven neutron noise analysis method for measuring the subcriticality of LWR fuel storage casks

    SciTech Connect

    Mihalczo, J.T.

    1987-01-01

    The /sup 252/Cf-source-driven neutron noise analysis method was evaluated to determine if it could be used to measure the subcriticality of storage casks of burnt light water reactor (LWR) fuel submerged in fuel storage pools, fully loaded and as they are being loaded. Measurements of k/sub eff/ would provide the parameter most directly related to the criticality safety of storage cask configurations of LWR fuel and could allow proper credit for fuel burnup without reliance on calculations. This, in turn, could lead to more cost-effective cask designs. Evaluation of the method for this application was based on experiments already completed at a critical experiments facility using arrays of pressurized water reactor (PWR) fuel pins typical of the size of storage cask configurations, the existence of neutron detectors that can function in shipping cask environments, and the ability to construct ionization chambers containing /sup 252/Cf of adequate intensity for these measurements.

  15. Preliminary economic evaluation of the use of graphite composite materials in surface transportation, phase 1 results

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Composite materials are discussed with emphasis on the identification of the characteristics of those materials that make them attractive for use in surface transportation. Potential uses of graphite composites are given including automotive applications and the effects of materials substitution on vehicle characteristics and performance. Preliminary estimates of the economic effects of the use of graphite composite materials on vehicle manufacturers and consumers are included. The combined impact on the national economy of vehicle design changes to meet mandated fuel efficiency requirements and the extensive use of graphite composite materials in the automotive industry is considered.

  16. PRELIMINARY EVALUATION OF LANDSAT-4 THEMATIC MAPPER DATA FOR THEIR GEOMETRIC AND RADIOMETRIC ACCURACIES.

    USGS Publications Warehouse

    Podwysoki, M.H.; Falcone, N.; Bender, L.U.; Jones, O.D.; ,

    1985-01-01

    This report describes results of some preliminary analyses of Landsat-4 Thematic Mapper data for the NASA Landsat Image Quality Analysis program. The work is being done under interagency agreement S-12407-C between the U. S. Geological Survey and NASA-Goddard Space Flight Center. Landsat-4 TM scenes for Washington, D. C. Macon, Georgia (40050-15333, September 4, 1982) and Cape Canaveral, Florida have been examined to determine their geometric and radiometric accuracy. In addition, parts of these scenes are also being analyzed to determine the ability to identify specific rock types with the added near-infrared TM bands.

  17. Preliminary In Vivo Evaluation of a Hybrid Armored Vascular Graft Combining Electrospinning and Additive Manufacturing Techniques.

    PubMed

    Spadaccio, Cristiano; Nappi, Francesco; De Marco, Federico; Sedati, Pietro; Sutherland, Fraser W H; Chello, Massimo; Trombetta, Marcella; Rainer, Alberto

    2016-01-01

    In this study, we tested in vivo effectiveness of a previously developed poly-l-lactide/poly-ε-caprolactone armored vascular graft releasing heparin. This bioprosthesis was designed in order to overcome the main drawbacks of tissue-engineered vascular grafts, mainly concerning poor mechanical properties, thrombogenicity, and endothelialization. The bioprosthesis was successfully implanted in an aortic vascular reconstruction model in rabbits. All grafts implanted were patent at four weeks postoperatively and have been adequately populated by endogenous cells without signs of thrombosis or structural failure and with no need of antiplatelet therapy. The results of this preliminary study might warrant for further larger controlled in vivo studies to further confirm these findings.

  18. Preliminary evaluation of Raboral V-RG® oral rabies vaccine in Arctic foxes (Vulpes lagopus).

    PubMed

    Follmann, Erich; Ritter, Don; Swor, Rhonda; Dunbar, Mike; Hueffer, Karsten

    2011-10-01

    We tested the Raboral V-RG® recombinant oral rabies vaccine for its response in Arctic foxes (Vulpes lagopus), the reservoir of rabies virus in the circumpolar North. The vaccine, which is currently the only licensed oral rabies vaccine in the United States, induced a strong antibody response and protected foxes against a challenge of 500,000 mouse intracerebral lethal dose 50% of an Arctic rabies virus variant. However, one unvaccinated control fox survived challenge with rabies virus, either indicating a high resistance of Arctic foxes to rabies infection or a previous exposure that induced immunity. This preliminary study suggested that Raboral V-RG vaccine may be efficacious in Arctic foxes.

  19. UAS Integration into the NAS: iHTL: DAA Display Evaluation Preliminary Results

    NASA Technical Reports Server (NTRS)

    Fern, Lisa; Rorie, Conrad; Shively, Jay

    2014-01-01

    The integrated human-in-the-loop (iHITL) simulation examined the effect of four different Detect-and-Avoid (DAA) display concepts on unmanned aircraft system (UAS) pilots' ability to maintain safe separation. The displays varied in the type and amount of guidance they provided to pilots. The study's background and methodology are discussed, followed by a presentation of the preliminary 'measured response' data (i.e., pilots' end-to-end response time in reacting to traffic alerts on their DAA display). Results indicate that display type had moderate to no affect on pilot measured response times.

  20. AFCI-2.0 Library of Neutron Cross Section Covariances

    SciTech Connect

    Herman, M.; Herman,M.; Oblozinsky,P.; Mattoon,C.; Pigni,M.; Hoblit,S.; Mughabghab,S.F.; Sonzogni,A.; Talou,P.; Chadwick,M.B.; Hale.G.M.; Kahler,A.C.; Kawano,T.; Little,R.C.; Young,P.G.

    2011-06-26

    Neutron cross section covariance library has been under development by BNL-LANL collaborative effort over the last three years. The primary purpose of the library is to provide covariances for the Advanced Fuel Cycle Initiative (AFCI) data adjustment project, which is focusing on the needs of fast advanced burner reactors. The covariances refer to central values given in the 2006 release of the U.S. neutron evaluated library ENDF/B-VII. The preliminary version (AFCI-2.0beta) has been completed in October 2010 and made available to the users for comments. In the final 2.0 release, covariances for a few materials were updated, in particular new LANL evaluations for {sup 238,240}Pu and {sup 241}Am were adopted. BNL was responsible for covariances for structural materials and fission products, management of the library and coordination of the work, while LANL was in charge of covariances for light nuclei and for actinides.

  1. A Preliminary Guide for Conducting Naturalistic Evaluation in Studying Museum Environment.

    ERIC Educational Resources Information Center

    Wolf, Robert L.; Tymitz, Barbara L.

    This document presents guidelines for use by museum staff members as they evaluate their institutional capabilities and programs. Guidelines are based on a new evaluation perspective--naturalistic evaluation--which can help museum staff assess their programs in a more interpretative, less judgmental way. Naturalistic evaluation is characterized by…

  2. Synthesis and in vitro evaluation of thiododecaborated α, α- cycloalkylamino acids for the treatment of malignant brain tumors by boron neutron capture therapy.

    PubMed

    Hattori, Yoshihide; Kusaka, Shintaro; Mukumoto, Mari; Ishimura, Miki; Ohta, Yoichiro; Takenaka, Hiroshi; Uehara, Kouki; Asano, Tomoyuki; Suzuki, Minoru; Masunaga, Shin-Ichiro; Ono, Koji; Tanimori, Shinji; Kirihata, Mitsunori

    2014-12-01

    Boron-neutron capture therapy (BNCT) is an attractive technique for cancer treatment. As such, α, α-cycloalkyl amino acids containing thiododecaborate ([B12H11](2-)-S-) units were designed and synthesized as novel boron delivery agents for BNCT. In the present study, new thiododecaborate α, α-cycloalkyl amino acids were synthesized, and biological evaluation of the boron compounds as boron carrier for BNCT was carried out.

  3. Evaluation of the mental health benefits of yoga in a secondary school: a preliminary randomized controlled trial.

    PubMed

    Khalsa, Sat Bir S; Hickey-Schultz, Lynn; Cohen, Deborah; Steiner, Naomi; Cope, Stephen

    2012-01-01

    The goal of this study was to evaluate potential mental health benefits of yoga for adolescents in secondary school. Students were randomly assigned to either regular physical education classes or to 11 weeks of yoga sessions based upon the Yoga Ed program over a single semester. Students completed baseline and end-program self-report measures of mood, anxiety, perceived stress, resilience, and other mental health variables. Independent evaluation of individual outcome measures revealed that yoga participants showed statistically significant differences over time relative to controls on measures of anger control and fatigue/inertia. Most outcome measures exhibited a pattern of worsening in the control group over time, whereas changes in the yoga group over time were either minimal or showed slight improvements. These preliminary results suggest that implementation of yoga is acceptable and feasible in a secondary school setting and has the potential of playing a protective or preventive role in maintaining mental health.

  4. Preliminary Statistical Analysis of the 1995 Evaluation by NASA LaRC of the IAI Automatic Balance Calibration Machine

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Tripp, John S.

    1999-01-01

    The NASA Langley Research Center (LARC) participated in a national cooperative evaluation of the Israel Aircraft Industries (IAI) automatic balance calibration machine at Microcraft, San Diego in September 1995. A LaRC-designed six-component strain gauge balance was selected for test and calibration during LaRC's scheduled evaluation period. Eight calibrations were conducted using three selected experimental designs. Raw data were exported to LaRC facilities for reduction and statistical analysis using the techniques outlined in Tripp and Tcheng (1994). This report presents preliminary assessments of the results, and compares IAI calibration results with manual calibration results obtained at the Modern Machine and Tool Co., Inc. (MM & T). Newport News, VA. A more comprehensive report is forthcoming.

  5. Seismic Evaluation and Preliminary Design of Regular Setback Masonry Infilled Open Ground Storey RC Frame

    NASA Astrophysics Data System (ADS)

    Hashmi, Arshad K.

    2016-06-01

    Current seismic code presents certain stringent factors for defining frame as regular and irregular. Thereby these stringent factors only decide the type of analysis (i.e. equivalent static analysis or dynamic analysis) to be done. On the contrary, development of new simplified methods such as pushover analysis can give lateral load capacity of any structure (e.g. regular or irregular frame etc.) easily. Design by iterative procedure with the help of pushover analysis for serviceability requirement (i.e. inter storey drift limitation) provided by present seismic code, can provide an alternative to present practicing procedure. Present paper deals with regular setback frame in combination with vulnerable layout of masonry infill walls over the frame elevation (i.e. probable case of "Vertical Stiffness Irregularities"). Nonlinear time history analysis and Capacity Spectrum Method have been implemented to investigate the seismic performance of these frames. Finally, recently developed preliminary design procedure satisfying the serviceability criterion of inter storey drift limitation has been employed for the preliminary design of these frames.

  6. Radiological evaluation of the Cresco system in combination with Osseospeed implants: a preliminary 3-year report

    PubMed Central

    BALDINI, N.; DE SANCTIS, M.; CAGIDIACO, M.C.; BALLERI, P.; VIGNOLETTI, F.; GORACCI, C.; FERRARI, M.

    2014-01-01

    SUMMARY Aim. In this preliminary study, the 3-year radiological outcomes of Osseospeed implant-supported fixed complete or partial prostheses made with two different laboratory protocols were compared. Methods. A convenience sample of 34 patients, who were either partially or completely edentulous in either jaw, were randomly assigned to two groups, of 17 patients each, using either a traditional laboratory protocol (control group) or the Cresco one (test group). The study’s objective was an assessment of marginal bone loss around implants, measured on intraoral radiographs at 3-year follow-up. Results. None of the implants inserted was lost during the study and radiological measurements of marginal bone level changes revealed that the mean marginal bone loss was respectively 0,73±0,33mm for test group and 0,88±1,13mm for control group. The differences between test and control groups were not statistically significant. Conclusion. This preliminary study did not demonstrate statistically significant differences in marginal bone loss around implant-prostheses prepared with the two different laboratory protocols, over the 3-year observational period. PMID:25694796

  7. A method for using neutron elastic scatter to create a variable energy neutron beam from a nearly monoenergetic neutron source

    NASA Astrophysics Data System (ADS)

    Whetstone, Z. D.; Kearfott, K. J.

    2015-07-01

    This work describes preliminary investigation into the design of a compact, portable, variable energy neutron source. The proposed method uses elastic neutron scatter at specific angles to reduce the energy of deuterium-deuterium or deuterium-tritium (D-T) neutrons. The research focuses on D-T Monte Carlo simulations, both in idealized and more realistic scenarios. Systematic uncertainty of the method is also analyzed. The research showed promise, but highlighted the need for discrimination of multiply-scattered neutrons, either through a pulsed generator or associated particle imaging.

  8. SU-E-T-567: Neutron Dose Equivalent Evaluation for Pencil Beam Scanning Proton Therapy with Apertures

    SciTech Connect

    Geng, C; Schuemann, J; Moteabbed, M; Paganetti, H

    2015-06-15

    Purpose: To determine the neutron contamination from the aperture in pencil beam scanning during proton therapy. Methods: A Monte Carlo based proton therapy research platform TOPAS and the UF-series hybrid pediatric phantoms were used to perform this study. First, pencil beam scanning (PBS) treatment pediatric plans with average spot size of 10 mm at iso-center were created and optimized for three patients with and without apertures. Then, the plans were imported into TOPAS. A scripting method was developed to automatically replace the patient CT with a whole body phantom positioned according to the original plan iso-center. The neutron dose equivalent was calculated using organ specific quality factors for two phantoms resembling a 4- and 14-years old patient. Results: The neutron dose equivalent generated by the apertures in PBS is 4–10% of the total neutron dose equivalent for organs near the target, while roughly 40% for organs far from the target. Compared to the neutron dose equivalent caused by PBS without aperture, the results show that the neutron dose equivalent with aperture is reduced in the organs near the target, and moderately increased for those organs located further from the target. This is due to the reduction of the proton dose around the edge of the CTV, which causes fewer neutrons generated in the patient. Conclusion: Clinically, for pediatric patients, one might consider adding an aperture to get a more conformal treatment plan if the spot size is too large. This work shows the somewhat surprising fact that adding an aperture for beam scanning for facilities with large spot sizes reduces instead of increases a potential neutron background in regions near target. Changran Geng is supported by the Chinese Scholarship Council (CSC) and the National Natural Science Foundation of China (Grant No. 11475087)

  9. Cast Stone Oxidation Front Evaluation: Preliminary Results For Samples Exposed To Moist Air

    SciTech Connect

    Langton, C. A.; Almond, P. M.

    2013-11-26

    The rate of oxidation is important to the long-term performance of reducing salt waste forms because the solubility of some contaminants, e.g., technetium, is a function of oxidation state. TcO{sub 4}{sup -} in the salt solution is reduced to Tc(IV) and has been shown to react with ingredients in the waste form to precipitate low solubility sulfide and/or oxide phases. Upon exposure to oxygen, the compounds containing Tc(IV) oxidize to the pertechnetate ion, Tc(VII)O{sub 4}{sup -}, which is very soluble. Consequently the rate of technetium oxidation front advancement into a monolith and the technetium leaching profile as a function of depth from an exposed surface are important to waste form performance and ground water concentration predictions. An approach for measuring contaminant oxidation rate (effective contaminant specific oxidation rate) based on leaching of select contaminants of concern is described in this report. In addition, the relationship between reduction capacity and contaminant oxidation is addressed. Chromate (Cr(VI) was used as a non-radioactive surrogate for pertechnetate, Tc(VII), in Cast Stone samples prepared with 5 M Simulant. Cast Stone spiked with pertechnetate was also prepared and tested. Depth discrete subsamples spiked with Cr were cut from Cast Stone exposed to Savannah River Site (SRS) outdoor ambient temperature fluctuations and moist air. Depth discrete subsamples spiked with Tc-99 were cut from Cast Stone exposed to laboratory ambient temperature fluctuations and moist air. Similar conditions are expected to be encountered in the Cast Stone curing container. The leachability of Cr and Tc-99 and the reduction capacities, measured by the Angus-Glasser method, were determined for each subsample as a function of depth from the exposed surface. The results obtained to date were focused on continued method development and are preliminary and apply to the sample composition and curing / exposure conditions described in this report. The

  10. Evaluation of the Doppler-Broadening of Gamma-Ray Spectra from Neutron Inelastic Scattering on Light Nuclei

    SciTech Connect

    Womble, Phillip C.; Barzilov, Alexander; Novikov, Ivan; Howard, Joseph; Musser, Jason

    2009-03-10

    Neutron-induced gamma-ray reactions are extensively used in the nondestructive analysis of materials and other areas where the information about the chemical composition of a substance is crucial. The common technique to find the intensity of the gamma ray is to fit gamma-ray line shape with an analytical function, for example, a Gaussian. However, the Gaussian fitting may fail if the gamma-ray peak is Doppler-broadened since this leads to the miscalculation of the area of the peak and, therefore, to misidentification of the material. Due to momentum considerations, Doppler-broadening occurs primarily with gamma rays from neutron-induced inelastic scattering reactions with light nuclei. The recoiling nucleus of interest must have excited states whose lifetimes are much smaller than the time of flight in the material. We have examined various light nuclei bombarded by 14 MeV neutrons to predict when the peak shape of a neutron-induced gamma ray emitted from these nuclei will be Doppler-broadened. We have found that nearly all the gamma rays from neutron-induced gamma-ray reactions on light elements (A<20) are Doppler-broadened with only a few exceptions. This means that utilization of resolution curves derived from isotopic sources or thermal neutron capture reactions have little value in the analysis.

  11. Microscopic calculations of nuclear and neutron matter, symmetry energy and neutron stars

    DOE PAGES

    Gandolfi, S.

    2015-02-01

    We present Quantum Monte Carlo calculations of the equation of state of neutron matter. The equation of state is directly related to the symmetry energy and determines the mass and radius of neutron stars, providing then a connection between terrestrial experiments and astronomical observations. As a result, we also show preliminary results of the equation of state of nuclear matter.

  12. Loss-of-coolant accident analyses of the Advanced Neutron Source Reactor

    SciTech Connect

    Chen, N.C.J.; Yoder, G.L. ); Wendel, M.W. )

    1991-01-01

    Currently in the conceptual design stage, the Advanced Neutron Source Reactor (ANSR) will operate at a high heat flux, a high mass flux, an a high degree of coolant subcooling. Loss-of-coolant accident (LOCA) analyses using RELAP5 have been performed as part of an early evaluation of ANSR safety issues. This paper discusses the RELAP5 ANSR conceptual design system model and preliminary LOCA simulation results. Some previous studies were conducted for the preconceptual design. 12 refs., 7 figs.

  13. The neutron channeling phenomenon.

    PubMed

    Khanouchi, A; Sabir, A; Boulkheir, M; Ichaoui, R; Ghassoun, J; Jehouani, A

    1997-01-01

    Shields, used for protection against radiation, are often pierced with vacuum channels for passing cables and other instruments for measurements. The neutron transmission through these shields is an unavoidable phenomenon. In this work we study and discuss the effect of channels on neutron transmission through shields. We consider an infinite homogeneous slab, with a fixed thickness (20 lambda, with lambda the mean free path of the neutron in the slab), which contains a vacuum channel. This slab is irradiated with an infinite source of neutrons on the left side and on the other side (right side) many detectors with windows equal to 2 lambda are placed in order to evaluate the neutron transmission probabilities (Khanouchi, A., Aboubekr, A., Ghassoun, J. and Jehouani, A. (1994) Rencontre Nationale des Jeunes Chercheurs en Physique. Casa Blanca Maroc; Khanouchi, A., Sabir, A., Ghassoun, J. and Jehouani, A. (1995) Premier Congré International des Intéractions Rayonnements Matière. Eljadida Maroc). The neutron history within the slab is simulated by the Monte Carlo method (Booth, T. E. and Hendricks, J. S. (1994) Nuclear Technology 5) and using the exponential biasing technique in order to improve the Monte Carlo calculation (Levitt, L. B. (1968) Nuclear Science and Engineering 31, 500-504; Jehouani, A., Ghassoun, J. and Aboubker, A. (1994) In Proceedings of the 6th International Symposium on Radiation Physics, Rabat, Morocco). Then different geometries of the vacuum channel have been studied. For each geometry we have determined the detector response and calculated the neutron transmission probability for different detector positions. This neutron transmission probability presents a peak for the detectors placed in front of the vacuum channel. This study allowed us to clearly identify the neutron channeling phenomenon. One application of our study is to detect vacuum defects in materials.

  14. The Utility of Pitch Elevation in the Evaluation of Oropharyngeal Dysphagia: Preliminary Findings

    ERIC Educational Resources Information Center

    Malandraki, Georgia A.; Hind, Jacqueline A.; Gangnon, Ronald; Logemann, Jeri A.; Robbins, JoAnne

    2011-01-01

    Purpose: To evaluate the utility of a pitch elevation task in the assessment of oropharyngeal dysphagia. Method: This study was a pilot prospective cohort study including 40 consecutive patients (16 male and 24 female) who were referred by their physician for a swallowing evaluation. Patients were evaluated with a noninstrumental clinical…

  15. Preliminary Design, Feasibility and Cost Evaluation of 1- to 15-Kilometer Height Steel Towers

    NASA Technical Reports Server (NTRS)

    Shanker, Ajay

    2003-01-01

    Design and construction of tall towers is an on-going research program of NASA. The agency has already done preliminary review in this area and has determined that multi-kilometer height towers are technically and economically feasible. The proposed towers will provide high altitude launch platforms reaching above eighty percent of Earth's atmosphere and provide tremendous gains in the potential energy as well as substantial reduction in aerodynamic drag. NASA has also determined that a 15-KM tower will have many useful applications in: (i)Meteorology,(ii)Oceanography, (iii)Astronomy, (iv)High Altitude Launch, (v)Physics Drop Tower, (vi) Biosphere Research, (vii) Nanotechnology, (viii) Energy/Power, (ix)Broadband Wireless Technology, (x)Space Transportation and (xi)Space Tourism.

  16. Economic Evaluation of Short-Term Wind Power Forecasts in ERCOT: Preliminary Results; Preprint

    SciTech Connect

    Orwig, K.; Hodge, B. M.; Brinkman, G.; Ela, E.; Milligan, M.; Banunarayanan, V.; Nasir, S.; Freedman, J.

    2012-09-01

    Historically, a number of wind energy integration studies have investigated the value of using day-ahead wind power forecasts for grid operational decisions. These studies have shown that there could be large cost savings gained by grid operators implementing the forecasts in their system operations. To date, none of these studies have investigated the value of shorter-term (0 to 6-hour-ahead) wind power forecasts. In 2010, the Department of Energy and National Oceanic and Atmospheric Administration partnered to fund improvements in short-term wind forecasts and to determine the economic value of these improvements to grid operators, hereafter referred to as the Wind Forecasting Improvement Project (WFIP). In this work, we discuss the preliminary results of the economic benefit analysis portion of the WFIP for the Electric Reliability Council of Texas. The improvements seen in the wind forecasts are examined, then the economic results of a production cost model simulation are analyzed.

  17. A Preliminary Evaluation of Child Restraints and Anchorage Systems for an Australian Car

    PubMed Central

    Charlton, Judith L.; Fildes, Brian; Laemmle, Ronald; Smith, Stuart; Douglas, Fiona

    2004-01-01

    This study examined the performance of three rear-facing and two forward-facing child restraints (CRS) with three anchorage systems: standard seatbelt, LATCH (flexible) and ISOFIX (rigid). Frontal (64 km/h) and side impact (15 km/h) HyGe sled tests were conducted using a sedan buck. Overall, the preliminary findings suggested superior performance of rigid over seatbelt and flexible anchorages, particularly in side impacts. The results also suggest a need for design improvement for CRS with flexible anchorages to increase stability in side impacts. The findings have important implications for the proposed introduction of changes to Australian Standards for CRS to permit both flexible and rigid systems to coexist with conventional seatbelt anchorage systems. PMID:15319118

  18. Preliminary evaluation of environmental issues on the use of peat as an energy source

    SciTech Connect

    King, R.; Richardson, S.; Walters, A.; Boesch, L.; Thomson, W.; Irons, J.

    1980-03-14

    A study to characterize the environmental issues, that would arise from an extensive peat utilization program has been initiated. The objectives of this preliminary report are to: identify the environmental issues and potential problems; examine the significance of issues in the geographical regions where peat use could be developed; and establish a methodology by which issues can be resolved or clarified through future coordinated private, state, and federal programs. An overview of peat development including discussions on conversion technologies, extraction and harvesting procedures, and land reclamation is presented. Environmental concerns are in the areas of water resources and quality, air quality, health and safety issues, solid waste management, and land reclamation. The general environmental issues, resource availability, and attitudes associated with potential peat development in ten states, containing an estimated 90 percent of US peat resources were described. The ten states reviewed are Alaska, Minnesota, Michigan, Maine, North and South Carolina, Wisconsin, New York, Florida, and Louisiana. (DMC)

  19. EVALUATION OF AN ACTIVE PERSONAL DOSIMETRY SYSTEM IN INTERVENTIONAL RADIOLOGY AND NEURORADIOLOGY: PRELIMINARY RESULTS.

    PubMed

    Mangiarotti, M; D'Ercole, L; Quaretti, P; Moramarco, L; Lafe, E; Zappoli Thyrion, F

    2016-12-01

    Active personal dosimeters (APD) supply real-time data on radiation dose rates and equivalent doses, enabling reduction of operator exposure to radiation in diagnostic and surgical procedures. Data from the use of the Raysafe i2 APD system in an angiography room are reported. Preliminary characterisation of the APD system was first carried out in terms of angular dependence and of Hp(10) response during the simulation of five typical surgical protocols. Reference measurements, simultaneously obtained from TLDs, were used to obtain a correction factor. APD data for patients and for primary and secondary operators were then recorded over 52 surgical procedures. The correlation between kerma air product (KAP) and reference point air kerma (Kar) and operator dose as a function of position with respect to the source of radiation is reported. The data indicate that the APD system could help operators to optimise behaviours and use of room protection to effectively minimise radiation dose.

  20. Preliminary In Vivo Evaluation of a Hybrid Armored Vascular Graft Combining Electrospinning and Additive Manufacturing Techniques

    PubMed Central

    Spadaccio, Cristiano; Nappi, Francesco; De Marco, Federico; Sedati, Pietro; Sutherland, Fraser W.H.; Chello, Massimo; Trombetta, Marcella; Rainer, Alberto

    2016-01-01

    In this study, we tested in vivo effectiveness of a previously developed poly-l-lactide/poly-ε-caprolactone armored vascular graft releasing heparin. This bioprosthesis was designed in order to overcome the main drawbacks of tissue-engineered vascular grafts, mainly concerning poor mechanical properties, thrombogenicity, and endothelialization. The bioprosthesis was successfully implanted in an aortic vascular reconstruction model in rabbits. All grafts implanted were patent at four weeks postoperatively and have been adequately populated by endogenous cells without signs of thrombosis or structural failure and with no need of antiplatelet therapy. The results of this preliminary study might warrant for further larger controlled in vivo studies to further confirm these findings. PMID:26949333

  1. Neutron detector

    DOEpatents

    Stephan, Andrew C.; Jardret; Vincent D.

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  2. Next Generation Munitions Handler: Human-Machine Interface and Preliminary Performance Evaluation

    SciTech Connect

    Draper, J.V.; Jansen, J.F.; Pin, F.G.; Rowe, J.C.

    1999-04-25

    The Next Generation Munitions Handler/Advanced Technology Demonstrator (NGMI-VATTD) is a technology demonstrator for the application of an advanced robotic device for re-arming U.S. Air Force (USAF) and U.S. Navy (USN) tactical fighters. It comprises two key hardware components: a heavy-lift dexterous manipulator (HDM) and a nonholonomic mobility platform. The NGMWATTD is capable of lifting weapons up to 4400 kg (2000 lb) and placing them on any weapons rack on existing fighters (including the F-22 Raptor). This report describes the NGMH mission with particular reference to human-machine interfaces. It also describes preliminary testing to garner feedback about the heavy-lift manipulator arm from experienced fighter load crewmen. The purpose of the testing was to provide preliminary information about control system parameters and to gather feed- back from users about manipulator arm functionality. To that end, the Air Force load crewmen interacted with the NGMWATTD in an informal testing session and provided feedback about the performance of the system. Certain con- trol system parameters were changed during the course of the testing and feedback from the participants was used to make a rough estimate of "good" initial operating parameters. Later, formal testing will concentrate within this range to identify optimal operating parameters. User reactions to the HDM were generally positive, All of the USAF personnel were favorably impressed with the capabilities of the system. Fine-tuning operating parameters created a system even more favorably regarded by the load crews. Further adjustment to control system parameters will result in a system that is operationally efficient, easy to use, and well accepted by users.

  3. Estimation of Orbital Neutron Detector Spatial Resolution by Systematic Shifting of Differential Topographic Masks

    NASA Technical Reports Server (NTRS)

    McClanahan, T. P.; Mitrofanov, I. G.; Boynton, W. V.; Chin, G.; Livengood, T.; Starr, R. D.; Evans, L. G.; Mazarico, E.; Smith, D. E.

    2012-01-01

    We present a method and preliminary results related to determining the spatial resolution of orbital neutron detectors using epithermal maps and differential topographic masks. Our technique is similar to coded aperture imaging methods for optimizing photonic signals in telescopes [I]. In that approach photon masks with known spatial patterns in a telescope aperature are used to systematically restrict incoming photons which minimizes interference and enhances photon signal to noise. Three orbital neutron detector systems with different stated spatial resolutions are evaluated. The differing spatial resolutions arise due different orbital altitudes and the use of neutron collimation techniques. 1) The uncollimated Lunar Prospector Neutron Spectrometer (LPNS) system has spatial resolution of 45km FWHM from approx. 30km altitude mission phase [2]. The Lunar Rennaissance Orbiter (LRO) Lunar Exploration Neutron Detector (LEND) with two detectors at 50km altitude evaluated here: 2) the collimated 10km FWHM spatial resolution detector CSETN and 3) LEND's collimated Sensor for Epithermal Neutrons (SETN). Thus providing two orbital altitudes to study factors of: uncollimated vs collimated and two average altitudes for their effect on fields-of-view.

  4. Assessment of the neutron cross section database for mercury for the ORNL spallation source

    SciTech Connect

    Leal, L.C.; Spencer, R.R.; Ingersoll, D.T.; Gabriel, T.A.

    1996-06-01

    Neutron source generation based on a high energy particle accelerator has been considered as an alternative to the canceled Advanced Neutron Source project at Oak Ridge National Laboratory. The proposed technique consists of a spallation neutron source in which neutrons are produced via the interaction of high-energy charged particles in a heavy metal target. Preliminary studies indicate that liquid mercury bombarded with GeV protons provides an excellent neutron source. Accordingly, a survey has been made of the available neutron cross-section data. Since it is expected that spectral modifiers, specifically moderators, will also be incorporated into the source design, the survey included thermal energy, resonance region, and high energy data. It was found that data of individual isotopes were almost non-existent and that the only evaluation found for the natural element had regions of missing data or discrepant data. Therefore, it appears that to achieve the desired degree of accuracy in the spallation source design it is necessary to re-evaluate the mercury database including making new measurements. During the presentation the currently available data will be presented and experiments proposed which can lead to design quality cross sections.

  5. Configuration evaluation and criteria plan. Volume 2: Evaluation critera plan (preliminary). Space Transportation Main Engine (STME) configuration study

    NASA Technical Reports Server (NTRS)

    Bair, E. K.

    1986-01-01

    The unbiased selection of the Space Transportation Main Engine (STME) configuration requires that the candidate engines be evaluated against a predetermined set of criteria which must be properly weighted to emphasize critical requirements defined prior to the actual evaluation. The evaluation and selection process involves the following functions: (1) determining if a configuration can satisfy basic STME requirements (yes/no); (2) defining the evaluation criteria; (3) selecting the criteria relative importance or weighting; (4) determining the weighting sensitivities; and (5) establishing a baseline for engine evaluation. The criteria weighting and sensitivities are cost related and are based on mission models and vehicle requirements. The evaluation process is used as a coarse screen to determine the candidate engines for the parametric studies and as a fine screen to determine concept(s) for conceptual design. The criteria used for the coarse and fine screen evaluation process is shown. The coarse screen process involves verifying that the candidate engines can meet the yes/no screening requirements and a semi-subjective quantitative evaluation. The fine screen engines have to meet all of the yes/no screening gates and are then subjected to a detailed evaluation or assessment using the quantitative cost evaluation processes. The option exists for re-cycling a concept through the quantitative portion of the screening and allows for some degree of optimization. The basic vehicle is a two stage LOX/HC, LOX/LH2 parallel burn vehicle capable of placing 150,000 lbs in low Earth orbit (LEO).

  6. Atmospheric neutrons

    NASA Technical Reports Server (NTRS)

    Preszler, A. M.; Moon, S.; White, R. S.

    1976-01-01

    Additional calibrations of the University of California double-scatter neutron detector and additional analysis corrections lead to slightly changed neutron fluxes. The theoretical angular distributions of Merker (1975) are in general agreement with the reported experimental fluxes but do not give the peaks for vertical upward and downward moving neutrons. The theoretical neutron escape current is in agreement with the experimental values from 10 to 100 MeV. The experimental fluxes obtained agree with those of Kanbach et al. (1974) in the overlap region from 70 to 100 MeV.

  7. A binding energy study of the Atomic Mass Evaluation 2012 and an updated beta-decay study of neutron-rich 74Cu

    NASA Astrophysics Data System (ADS)

    Tracy, James L., Jr.

    A study of ground state binding energy values listed in the Atomic Mass Evaluation 2012 (AME2012) using an interpretive approach, as opposed to the exploratory methods of previous models, is presented. This model is based on a postulate requiring all protons to pair with available neutrons to form bound alpha clusters as the ground state for an N = Z core upon which excess neutrons are added. For each core, the trend of the binding energy as a function of excess neutrons in the isotopic chain can be fit with a three-term quadratic function. The quadratic parameter reveals a smooth decaying exponential function. By re-envisioning the determination of mass excess, the constant-term fit parameters, representing N = Z nuclei, reveal a near-symmetry around Z = 50. The linear fit parameters exhibit trends which are linear functions of core size. A neutron drip-line prediction is compared against current models. By considering the possibility of an alpha-cluster core, a new ground-state structure grouping scheme is presented; nucleon-nucleon pairing is shown to have a greater role in level filling. This model, referred to as the Alpha-Deuteron-Neutron Model, yields promising first results when considering root-mean-square variances from the AME2012. The beta-decay of the neutron-rich isotope 74Cu has been studied using three high-purity Germanium clover detectors at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. A high-resolution mass separator greatly improved the purity of the 74Cu beam by removing isobaric contaminants, thus allowing decay through its isobar chain to the stable 74Ge at the center of the LeRIBSS detector array without any decay chain member dominating. Using coincidence gating techniques, 121 gamma-rays associated with 74Cu were isolated from the collective singles spectrum. Eighty-seven of these were placed in an expanded level scheme, and updated beta-feeding level intensities and log( ft) values are presented based on

  8. Synthesis and evaluation of boron compounds for neutron capture therapy of malignant brain tumors. Technical progress report No. 1, May 1, 1990--January 31, 1991

    SciTech Connect

    Soloway, A.H.; Barth, R.F.

    1990-12-31

    Boron neutron capture therapy offers the potentiality for treating brain tumors currently resistant to treatment. The success of this form of therapy is directly dependent upon the delivery of sufficient numbers of thermal-neutrons to tumor cells which possess high concentrations of B-10. The objective of this project is to develop chemical methodology to synthesize boron-containing compounds with the potential for becoming incorporated into rapidly-dividing malignant brain tumor cells and excluded from normal components of the brain and surrounding tissues, to develope biological methods for assessing the potential of the compound by use of cell culture or intratumoral injection, to develop analytical methodology for measuring boron in cells and tissue using direct current plasma atomic emission spectroscopy (DCP-AES) and alpha track autoradiography, to develop biochemical and HPLC procedures for evaluating compound uptake and tissue half-life, and to develop procedures required to assess both in vitro and vivo efficacy of BNCT with selected compounds.

  9. The DAMPE Neutron Detector

    NASA Astrophysics Data System (ADS)

    Yan, Zhang; Tao, Ma; Yongyi, Huang

    2016-07-01

    The first Chinese space observatory DAMPE (DArk Matter Particle Explorer) was successfully launched on Dec. 17th, 2015. One major scientific object of DAMPE is to measure electrons between 5GeV to 10TeV with excellent energy resolution (1.5% at 800GeV) to search for possible dark matter signatures. The detector consists of four subsystems: a plastic scintillator detector (PSD), a silicon-tungsten tracker (STK), a BGO calorimeter (BGO), and a neutron detector (NUD). The NUD on board DAMPE is designed to detect moderated neutrons via the boron capture of thermal neutrons in boron-doped plastics. Given the fact that hadron showers initiated in the BGO calorimeter by incident nuclei tend to be followed by significantly more neutron activities comparing to electromagnetic cascades triggered by electrons, the NUD provides an additional order of magnitude hadron rejection capability to improve the overall e/p discrimination of DAMPE up to 10 ^{5}. Preliminary analysis of the in-orbit data is given, together with comparisons to the results obtained by a detailed GEANT4 simulation of the NUD instrument.

  10. First Evaluation of the Biologic Effectiveness Factors of Boron Neutron Capture Therapy (BNCT) in a Human Colon Carcinoma Cell Line

    SciTech Connect

    Dagrosa, Maria Alejandra; Crivello, Martin; Perona, Marina; Thorp, Silvia; Santa Cruz, Gustavo Alberto; Pozzi, Emiliano; Casal, Mariana; Thomasz, Lisa; Cabrini, Romulo; Kahl, Steven; Juvenal, Guillermo Juan; Pisarev, Mario Alberto

    2011-01-01

    Purpose: DNA lesions produced by boron neutron capture therapy (BNCT) and those produced by gamma radiation in a colon carcinoma cell line were analyzed. We have also derived the relative biologic effectiveness factor (RBE) of the neutron beam of the RA-3- Argentine nuclear reactor, and the compound biologic effectiveness (CBE) values for p-boronophenylalanine ({sup 10}BPA) and for 2,4-bis ({alpha},{beta}-dihydroxyethyl)-deutero-porphyrin IX ({sup 10}BOPP). Methods and Materials: Exponentially growing human colon carcinoma cells (ARO81-1) were distributed into the following groups: (1) BPA (10 ppm {sup 10}B) + neutrons, (2) BOPP (10 ppm {sup 10}B) + neutrons, (3) neutrons alone, and (4) gamma rays ({sup 60}Co source at 1 Gy/min dose-rate). Different irradiation times were used to obtain total absorbed doses between 0.3 and 5 Gy ({+-}10%) (thermal neutrons flux = 7.5 10{sup 9} n/cm{sup 2} sec). Results: The frequency of micronucleated binucleated cells and the number of micronuclei per micronucleated binucleated cells showed a dose-dependent increase until approximately 2 Gy. The response to gamma rays was significantly lower than the response to the other treatments (p < 0.05). The irradiations with neutrons alone and neutrons + BOPP showed curves that did not differ significantly from, and showed less DNA damage than, irradiation with neutrons + BPA. A decrease in the surviving fraction measured by 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium bromide (MTT) assay as a function of the absorbed dose was observed for all the treatments. The RBE and CBE factors calculated from cytokinesis block micronucleus (CBMN) and MTT assays were, respectively, the following: beam RBE: 4.4 {+-} 1.1 and 2.4 {+-} 0.6; CBE for BOPP: 8.0 {+-} 2.2 and 2.0 {+-} 1; CBE for BPA: 19.6 {+-} 3.7 and 3.5 {+-} 1.3. Conclusions: BNCT and gamma irradiations showed different genotoxic patterns. To our knowledge, these values represent the first experimental ones obtained for the RA-3 in a

  11. Preliminary evaluation of a virtual reality dental simulation system on drilling operation.

    PubMed

    Wang, Dangxiao; Zhao, Siming; Li, Teng; Zhang, Yuru; Wang, Xiaoyan

    2015-01-01

    To evaluate the fidelity of the iDental system and investigate its utility and performance on simulated drilling operations, user studies consisting of objective and subjective evaluations were performed. A voxel-based drilling simulation sub-system in the iDental system was employed for evaluation. Twenty participants were enrolled to take part in the experiments and were divided into two groups: novice and resident. A combined evaluation method including objective and subjective methods was employed. The objective evaluation included two dental drilling tasks: caries removal operation and pulp chamber opening operation. In the subjective method, participants were required to complete a questionnaire to evaluate the fidelity of the system after the operation task. Based on the structured global assessment scales in the questionnaire, the average subjective evaluation scores of the proposed metrics were greater than 4.5, demonstrating that the system operated above medium fidelity. Dentists expressed great interest and positive attitudes toward the potential of the iDental system. The objective evaluation data including time spent and the volume of removed healthy and carious tissue were obtained. Although no significant differences could be found between the two groups, the volume of removed caries and the depth of pulp chamber insertion manifested small standard deviations. Evaluation results illustrated that dentists were willing to use the virtual reality training system. Several future research topics were identified, including increasing the task difficulty, improving the system fidelity and introducing appropriate finger rest points.

  12. Site selection and preliminary evaluation of potential solar-industrial-process-heat applications for federal buildings in Texas

    SciTech Connect

    Branz, M A

    1980-09-30

    The potential for solr process heat applications for federal buildings in Texas is assessed. The three sites considered are Reese Air Force Base, Lubbock; Fort Bliss, El Paso; and Dyess Air Force Base, Abilene. The application at Lubbock is an electroplating and descaling facility for aircraft maintenance. The one at El Paso is a laundry facility. The Abilene system would use solar heat to preheat boiler feedwater makeup for the base hospital boiler plant. The Lubbock site is found to be the most appropriate one for a demonstration plant, with the Abilene site as an alternate. The processes at each site are described. A preliminary evaluation of the potential contribution by solar energy to the electroplating facility at Reese AFB is included. (LEW)

  13. Extraction, preliminary characterization and evaluation of in vitro antitumor and antioxidant activities of polysaccharides from Mentha piperita.

    PubMed

    Liu, Xin; Sun, Zhen-Liang; Jia, Ai-Rong; Shi, Ya-Ping; Li, Rui-Hong; Yang, Pei-Ming

    2014-09-15

    This study describes the extraction, preliminary characterization and evaluation of the in vitro antitumor and antioxidant activities of polysaccharides extracted from Mentha piperita (MPP). The optimal parameters for the extraction of MPP were obtained by Box-Behnken experimental design and response surface methodology (RSM) at the ratio of water to raw material of 20, extraction time of 1.5 h and extraction temperature at 80 °C. Chemical composition analysis showed that MPP was mainly composed of glucuronic acid, galacturonic acid, glucose, galactose and arabinose, and the molecular weight of its two major fractions were estimated to be about 2.843 and 1.139 kDa, respectively. In vitro bioactivity experiments showed that MPP not only inhibited the growth of A549 cells but possessed potent inhibitory action against DNA topoisomerase I (topo I), and an appreciative antioxidant action as well. These results indicate that MPP may be useful for developing safe natural health products.

  14. [Preliminary evaluation of the usefulness of vascular prostheses Protegraft DV 1900 manufactured by B. Braun Melsungen AG].

    PubMed

    Pardela, M; Woś, S; Witkowski, K; Gołab, K; Piecuch, J; Orkisz, W; Kozłowski, A

    1991-01-01

    The authors carried out preliminary clinical evaluation of usefulness of the knitted vascular prostheses Protegraft DV 1900 of B. Braun Melsungen AG's firm. 10 prostheses of that firm were used for investigation implanting biforked protheses to six patients and single prostheses to four patients. Such qualities were taken into account: their behaviour in the operation field during the operation so blood percolating through the wall, shredding of the edges, passing of the suture through the prostheses as well as wall rigor after blood coagulation. It was observed that the vascular prostheses Protegraft DV 1900 together with the advantages ascribed until now to prostheses from woven materials and, first of all, a very short period of bleeding through the wall after releasing the clip.

  15. Extraction, Preliminary Characterization and Evaluation of in Vitro Antitumor and Antioxidant Activities of Polysaccharides from Mentha piperita

    PubMed Central

    Liu, Xin; Sun, Zhen-Liang; Jia, Ai-Rong; Shi, Ya-Ping; Li, Rui-Hong; Yang, Pei-Ming

    2014-01-01

    This study describes the extraction, preliminary characterization and evaluation of the in vitro antitumor and antioxidant activities of polysaccharides extracted from Mentha piperita (MPP). The optimal parameters for the extraction of MPP were obtained by Box-Behnken experimental design and response surface methodology (RSM) at the ratio of water to raw material of 20, extraction time of 1.5 h and extraction temperature at 80 °C. Chemical composition analysis showed that MPP was mainly composed of glucuronic acid, galacturonic acid, glucose, galactose and arabinose, and the molecular weight of its two major fractions were estimated to be about 2.843 and 1.139 kDa, respectively. In vitro bioactivity experiments showed that MPP not only inhibited the growth of A549 cells but possessed potent inhibitory action against DNA topoisomerase I (topo I), and an appreciative antioxidant action as well. These results indicate that MPP may be useful for developing safe natural health products. PMID:25226538

  16. Neutron multiplicity ,easurements With 3He alternative: Straw neutron detectors

    DOE PAGES

    Mukhopadhyay, Sanjoy; Wolff, Ronald S.; Meade, John A.; ...

    2015-01-27

    Counting neutrons emitted by special nuclear material (SNM) and differentiating them from the background neutrons of various origins is the most effective passive means of detecting SNM. Unfortunately, neutron detection, counting, and partitioning in a maritime environment are complex due to the presence of high-multiplicity spallation neutrons (commonly known as “ship effect”) and to the complicated nature of the neutron scattering in that environment. In this study, a prototype neutron detector was built using 10B as the converter in a special form factor called “straws” that would address the above problems by looking into the details of multiplicity distributions ofmore » neutrons originating from a fissioning source. This paper describes the straw neutron multiplicity counter (NMC) and assesses the performance with those of a commercially available fission meter. The prototype straw neutron detector provides a large-area, efficient, lightweight, more granular (than fission meter) neutron-responsive detection surface (to facilitate imaging) to enhance the ease of application of fission meters. Presented here are the results of preliminary investigations, modeling, and engineering considerations leading to the construction of this prototype. This design is capable of multiplicity and Feynman variance measurements. This prototype may lead to a near-term solution to the crisis that has arisen from the global scarcity of 3He by offering a viable alternative to fission meters. This paper describes the work performed during a 2-year site-directed research and development (SDRD) project that incorporated straw detectors for neutron multiplicity counting. The NMC is a two-panel detector system. We used 10B (in the form of enriched boron carbide: 10B4C) for neutron detection instead of 3He. In the first year, the project worked with a panel of straw neutron detectors, investigated its characteristics, and developed a data acquisition (DAQ) system to collect

  17. Preliminary evaluation of septic-system absorption-field architecture types in a profile-limited soil.

    PubMed

    Mathis, Amanda J; Brye, Kristofor R; Dunn, Sam

    2011-01-01

    Managing household wastewater is an issue that affects hundreds of thousands of people in rural communities nationwide, many of whom rely on septic systems as their primary means of household wastewater disposal. Septic system absorption field products with architectures quite different from traditional pipe-and-gravel systems are being installed in many states with variances from initial design specifications. The objective of this study was to evaluate the performance, as measured by the in-product height of stored solution, of four differing absorption-field product architecture types in a profile-limited soil that was loaded at the maximum allowable rate based on soil morphology. Five chamber, two gravel-less pipe, two polystyrene aggregate, and four pipe-and-gravel systems were installed in a profile-limited, Captina silt loam soil (fine-silty, siliceous, active, mesic Typic Fragiudult) and dosed with raw effluent at rates determined by current State of Arkansas regulations via individual peristaltic pumps. Free-solution monitoring ports were installed within each product, where the depth to free solution was measured periodically and used to evaluate product performance. Data collected from January through August 2009 indicated that preliminary system performance was unaffected by product architecture type. All products performed similarly under dry soil conditions. However, differences among individual products were observed during periods of hydrologic stress (i.e., wet soil conditions). Surfacing of effluent was not observed atop any product, indicating that the current loading rate design method is functioning properly. Preliminary results indicate that some alternative absorption-field products perform similarly to the traditional pipe-and-gravel system, thus providing flexibility and options for homeowners.

  18. Development of a preliminary relative risk model for evaluating regional ecological conditions in the Delaware River Estuary, USA.

    PubMed

    Iannuzzi, Timothy J; Durda, Judi L; Preziosi, Damian V; Ludwig, David F; Stahl, Ralph G; DeSantis, Amanda A; Hoke, Robert A

    2010-01-01

    Effective environmental management and restoration of urbanized systems such as the Delaware River Estuary requires a holistic understanding of the relative importance of various stressor-related impacts throughout the watershed, both historical and ongoing. To that end, it is important to involve as many stakeholders as possible in the management process and to develop a system for sharing of scientific data and information, as well as effective technical tools for evaluating and disseminating the data needed to make management decisions. In this study, we describe a preliminary assessment that was undertaken to evaluate the relative risks for the variety of stressors currently operating within the Delaware Estuary using a relative risk model (RRM) framework. This model was constructed using existing data and information on the ecological conditions and stressors in the main-stem Delaware River below the head of tide at Trenton, New Jersey, USA. A large database was developed with pertinent data from a variety of library, scientific, and regulatory sources. Data were compiled, reviewed, and characterized before development of the Estuary-specific RRM. Our primary goals and objectives in developing this preliminary RRM for the Estuary were to 1) determine if the RRM framework can be adapted to a large complex estuarine system such as the Delaware River, 2) identify the issues associated with adapting the model framework to the various management issues and regional areas/habitats of the River, 3) help identify data needs and potential refinements that might be needed to more specifically quantify relative stressor risks in various areas and habitats of the Estuary to better inform future management goals/actions by Stakeholders. The key conclusions of our preliminary assessment are 1) a diverse suite of stressors is likely affecting the ecological conditions of the Delaware Estuary, 2) chemical (toxicants/contaminants) and physical (sedimentation, habitat loss

  19. The Development and Preliminary Evaluation of an Education Intervention to Prevent Driveway Run-Over Incidents

    ERIC Educational Resources Information Center

    Armstrong, Kerry A.; Watling, Hanna; Davey, Jeremy

    2016-01-01

    Objective: While driveway run-over incidents continue to be a cause of serious injury and deaths among young children in Australia, few empirically evaluated educational interventions have been developed which address these incidents. Addressing this gap, this study describes the development and evaluation of a paper-based driveway safety…

  20. Assessing QuADEM: Preliminary Notes on a New Method for Evaluating Online Language Learning Courseware

    ERIC Educational Resources Information Center

    Strobl, Carola; Jacobs, Geert

    2011-01-01

    In this article, we set out to assess QuADEM (Quality Assessment of Digital Educational Material), one of the latest methods for evaluating online language learning courseware. What is special about QuADEM is that the evaluation is based on observing the actual usage of the online courseware and that, from a checklist of 12 different components,…

  1. New JEFF-3.2 Sodium Neutron Induced Cross-sections Evaluation for Neutron Fast Reactors Applications: from 0 to 20 MeV

    NASA Astrophysics Data System (ADS)

    Archier, P.; Noguère, G.; De Saint Jean, C.; Plompen, A. J. M.; Rouki, C.

    2014-04-01

    In the framework of the ASTRID project, a new 23Na evaluation, containing re-evaluated nuclear data and associated covariances, has been prepared to be submitted for the future JEFF-3.2 library. This work has been motivated mainly because the current JEFF-3.1.1 sodium evaluation showed large differences with microscopic measurements and does not have covariances data. Recent experimental data from IRMM and high resolution measurements from Larson have been simultaneously analyzed with the data assimilation code CONRAD and a good agreement with the evaluated cross-sections has been achieved. Experimental systematic uncertainties have been propagated to the nuclear reaction model parameters in order to produce a coherent set of covariance data. Several figures are provided in this paper to illustrate the new features of this evaluation.

  2. Evaluation of the spectrometric and dose characteristics of neutron fields inside the Russian segment of the ISS by fission detectors

    NASA Astrophysics Data System (ADS)

    Shurshakov, V. A.; Vorob'ev, I. B.; Nikolaev, V. A.; Lyagushin, V. I.; Akatov, Yu. A.; Kushin, V. V.

    2016-03-01

    The results of measuring the dose and the energy spectrum of neutrons inside the Russian segment of the International Space Station (ISS) from March 21 until November 10, 2002 are presented. Statistically reliable results of measurement are obtained by using thorium- and uranium-based fission detectors with cadmium and boron filters. The kits of the detectors with filters have been arranged in three compartments within assembled passive detectors in the BRADOS space experiment. The ambient dose rate H* = 139 μSv day and an energy spectrum of neutrons in the range of 10-2-104 MeV is obtained as average for the ISS compartments and is compared with the measurements carried out inside the compartments of the MIR space station. Recommendations on how to improve the procedure for using the fission detectors to measure the characteristics of neutron fields inside the compartments of space stations are formulated.

  3. Synthesis, evaluation and preliminary antibacterial testing of hybrid composites based on urethane oligodimethacrylates and Ag nanoparticles.

    PubMed

    Buruiana, Tinca; Melinte, Violeta; Chibac, Andreea; Matiut, Simona; Balan, Lavinia

    2012-01-01

    A series of urethane dimethacrylates differing structurally by the nature of the spacer (PTHF, PCL, PEG) and the presence or absence of the carboxylic acid groups was synthesized via an isocyanate route frequently encountered in ionomer chemistry. (1)H-NMR and FT-IR spectroscopy confirmed the structure of the macromers. Subsequently, the progress of photo-polymerization of all dimethacrylates under UV irradiation was investigated by FT-IR spectroscopy and photo-DSC with respect to conversion and polymerization rate using Irgacure as an initiator. The results of spectroscopic analysis suggested the lower reactivity of some non-carboxylic analogues during the formation of cross-linked polymers, the degree of conversion depending on the structure and viscosity. Photo-polymerization may provide many advantages for incorporating silver nanoparticles (2.5 wt%) into macromers in order to obtain hybrid nanocomposite films with controllable thickness and hydrophobicity. Combined analyses of UV spectroscopy and transmission electron microscopy confirmed the existence of nanosized silver (mean diameter 12 ± 0.7 nm) uniformly distributed in the polymer matrix. Preliminary results concerning the antibacterial activity of some composite films (thickness approx. 24 μm) showed that the obtained nanomaterial could have an excellent bactericidal effect and effectiveness in reducing bacterial growth (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923).

  4. Preliminary evaluation of an experimental clinical chemistry analyzer developed for space medicine.

    PubMed

    Wu, A H; Gornet, T G; Schenkel, O; Smith-Cronin, L; Graham, G A; Tonnesen, A S; McKinley, B A

    1993-01-01

    An experimental clinical chemistry analyzer system was designed and built to demonstrate the feasibility of clinical chemistry as part of a medical-care system at NASA's planned space station Freedom. We report the performance of the experimental analyzer, called a medical development unit (MDU), for selected analytes in a laboratory setting in preparation for a preliminary clinical trial at patients' bedsides in an intensive-care unit. Within-run CVs ranged from 0.7% for sodium to 7.1% for phosphorus; day-to-day CVs ranged from 1.0% for chloride to 23.4% for calcium. Correlation of patients' blood sample analyses compared well with those by Ektachem E700 and other high-volume central laboratory analyzers (r ranged from 0.933 for creatine kinase MB isoenzyme to 0.997 for potassium), except for hemoglobin (r = 0.901) and calcium (r = 0.823). Although several CVs obtained in this study exceeded theoretical desired precision limits based on biological variations, performance was adequate for clinical laboratory diagnosis. We examined the effect of potentially interfering concentrations of hemoglobin, bilirubin, and lipids: the only effect was negative interference with calcium analyses by high concentrations of bilirubin. We also examined the effects of preanalytical variables and the performance of experimental sample-transfer cups designed to retain sample and reference liquid in microgravity. Continued development of the MDU system is recommended, especially automation of sample processing.

  5. A preliminary evaluation of the relationship between bioconcentration and hydrophobicity for surfactants

    SciTech Connect

    Tolls, J.; Sijm, D.T.H.M.

    1995-10-01

    A statistical analysis was done of the relationship between hydrophobicity and bioconcentration parameters (uptake and elimination rate constants and bioconcentration factor) predicted by the diffusive mass-transfer (DMT) concept of bioconcentration developed previously. The authors employed polychlorinated biphenyls and benzenes (PCB/zs) as model compounds and the octanol/water partition coefficient as hydrophobicity parameter. They conclude that the model is consistent with the data. Subsequently, they applied the DMT concept to a set of preliminary bioconcentration data for surfactants using the critical micelle concentration (CMC) as hydrophobicity parameter. The obtained relationships qualitatively agree with the DMT concept, indicating that hydrophobicity is of great influence on surfactant bioconcentration. Finally, they investigated the hydrophobicity-bioconcentration relationships of surfactants and PCB/zs using aqueous solubility as common hydrophobicity parameter and found the relationships between the bioconcentration parameters and hydrophobicity to agree with the DMT concept. These findings are based on total radiolabel data. Therefore, they need to be confirmed using compound-specific surfactant bioconcentration data.

  6. Preliminary Mission Results and Project Evaluation of the Delfi-C3 Nano-satellite

    NASA Astrophysics Data System (ADS)

    Bouwmeester, J.; Aalbers, G. T.; Ubbels, W. J.

    2008-08-01

    This paper discusses preliminary mission results of Delfi-C3 up till the early operations phase. The first section will discuss the design philosophy of Delfi-C3. To reduce operational risks, Delfi-C3 followed the KISS principle and is designed to be Single-Point-of-Failure- free. A balance is made between adoption of professional space engineering customs and standards on one hand and the limitations of small satellites, financial budgets and limited human resources on the other hand. The second section of the paper discusses the project planning and management of Delfi-C3. Addressed are reasonable timelines for the development of a nano-satellite, how to deal with a launch slip and the occasional conflicts between the interest of the students and the interest of the project. The third section of the paper will present the results of the early operations of Delfi-C3. Discussed are the performance of the payloads, the bus and the ground network of the satellite. Finally, an early statement of the mission success will be given.

  7. Upper limb vibration prototype with sports and rehabilitation applications: development, evaluation and preliminary study

    PubMed Central

    Neilson, Richard D.; Aphale, Sumeet S.; Cardinale, Marco

    2017-01-01

    Vibration stimulation as an exercise intervention has been studied increasingly for its potential benefits and applications in sports and rehabilitation. Vibratory exercise devices should be capable of generating highly precise and repeatable vibrations and should be capable of generating a range of vibration amplitudes and frequencies in order to provide different training protocols. Many devices used to exercise the upper body provide limited variations to exercise regimes mostly due to the fact that only vibration frequency can be controlled. The authors present an upper limb vibration exercise device with a novel actuator system and design which attempts to address these limitations. Preliminary results show that this device is capable of generating highly precise and repeatable vibrations with independent control over amplitude and frequency. Furthermore, the results also show that this solution provides a higher neuromuscular stimulation (i.e. electromyography activity) when compared with a control condition. The portability of this device is an advantage, and though in its current configuration it may not be suitable for applications requiring higher amplitude levels the technology is scalable. PMID:28261493

  8. Biogeographic perspective of speciation among desert tortoises in the genus Gopherus: a preliminary evaluation

    USGS Publications Warehouse

    Edwards, Taylor; Vaughn, Mercy; Meléndez Torres, Cristina; Karl, Alice E.; Rosen, Philip C.; Berry, Kristin H.; Murph, Robert W.

    2013-01-01

    The enduring processes of time, climate, and adaptation have sculpted the distribution of organisms we observe in the Sonoran Desert. One such organism is Morafka’s desert tortoise, Gopherus morafkai. We apply a genomic approach to identify the evolutionary processes driving diversity in this species and present preliminary findings and emerging hypotheses. The Sonoran Desert form of the tortoise exhibits a continuum of genetic similarity spanning 850 km of Sonoran desertscrub extending from Empalme, Sonora, to Kingman, Arizona. However, at the ecotone between desertscrub and foothills thornscrub we identify a distinct, Sinaloan lineage and this occurrence suggests a more complex evolutionary history for G. morafkai. By using multiple loci from throughout the tortoise’s genome, we aim to determine if divergence between these lineages occurred in allopatry, and further to investigate for signatures of past or current genetic introgression. This international, collaborative project will assist state and federal agencies in developing management strategies that best preserve the evolutionary potential of Morafka’s desert tortoise. Ultimately, an understanding of the evolutionary history of desert tortoises will not only clarify the forces that have driven the divergence in this group, but also contribute to our knowledge of the biogeographic history of the Southwestern deserts and how diversity is maintained within them.

  9. Preliminary evaluation of ground-water flow in Bear Creek Valley, the Oak Ridge Reservation, Tennessee

    USGS Publications Warehouse

    Bailey, Z.C.

    1988-01-01

    Bear Creek Valley, Tennessee contains hazardous waste disposal sites where contaminants leach into ground and surface water. Groundwater flow and the potential migration of contaminants is poorly understood. The Valley is underlain by calcareous shale that contains limestone units. Ridges to the north and south are underlain by interbedded sandstones, siltstone and shale, and by massive, siliceous dolomite, respectively. The bedrock, which dips about 45 degrees southeast, is overlain by regolith to a maximum thickness of 80 ft. Observed hydraulic conductivities for the regolith range from 0.01 to 13 ft/day, and for the bedrock, from 0.001 to 11 ft/day. Groundwater flow is probably toward streams and is preferential along strike because of an areal anisotropy in hydraulic conductivity. A cross sectional groundwater flow model was used to test the conceptualized flow system and to help identify areas where additional data are needed. The preliminary model shows a pattern of recharge at both ridges, flow toward the valley, and upward flow that discharges into Bear Creek. Final model values of hydraulic conductivity in the bedrock range from 0.01 to 0.1 ft/day and reflect an areal anisotropy ratio of 1:5. Simulated recharge was 10 inches/year. (USGS)

  10. Benthic foraminifera from two coastal lakes of southern Latium (Italy). Preliminary evaluation of environmental quality.

    PubMed

    Carboni, Maria Gabriella; Succi, Maria Cristina; Bergamin, Luisa; Di Bella, Letizia; Frezza, Virgilio; Landini, Bruna

    2009-01-01

    Benthic foraminifera and sediment texture were studied on a total of 37 samples, collected from two brackish-water coastal basins: Fogliano Lake and Lungo Lake (central Italy). The research was performed as a preliminary low-cost survey to highlight the degree of the environmental stress and to recognize a possible anthropogenic disturbance. The sedimentological and foraminiferal data were processed by bivariate and multivariate statistical analysis. Three distinct assemblages, referable to different environments were recognized for the Fogliano Lake: inner, intermediate and outer lagoon. Only the outer lagoon assemblage was found in the Lungo Lake. The distribution of foraminifera in the Fogliano Lake suggests a natural environmental stress probably due to the ecological instability typical of marginal environments, while the absence of the inner and intermediate lagoon assemblages in the Lungo Lake suggests an environmental disturbance possibly related to human activities. An interdisciplinary survey including geochemical analyses is recommended in order to deduce the nature and degree of pollution in the Lungo Lake.

  11. Large climate-moderating envelopes for enclosed structures: a preliminary evaluation of energy conservation potential

    SciTech Connect

    Wendt, R.L.; Giles, G.E.; Park, J.E.

    1981-12-01

    An investigation was made of the basic impacts of putting a large secondary enclosure around a number of functions and thereby creating a Large Climate Moderating Envelope (LCME). This study is a preliminary estimate of the energy conservation benefits of an LCME. A hypothetical LMCE design was chosen and a coupled fluid dynamic and energy transport analysis was performed to estimate the energy conservation potential of this design. The heat transfer models included insolation, outside air temperature and wind, thermal radiation exchange with the sky, and between the fabric and ground and thermal storage in the earth mass beneath the LCME. The energy transported within the fluid by the buoyancy driven circulation was modeled as an incompressible fluid utilizing the Boussinesq approximation. The climatic conditions were assumed to vary in smooth repeating daily cycles. The numerical simulation of climatic variation was continued until the results within the LCME achieved a repeating daily cycle. The results for selected seasonally characteristic days were utilized to estimate the annual energy consumption of structures within an LCME relative to similar structures exposed to the exterior environment. The relative annual energy savings for summer-dominated climates was estimated to be approx. 70%. The energy savings for a winter-dominated climate LCME were estimated to be somewhat smaller but the LCME concept could offer significant benefits for agricultural applications for this type of climate.

  12. Sewage sludge drying by energy recovery from OFMSW composting: preliminary feasibility evaluation.

    PubMed

    Rada, Elena Cristina; Ragazzi, Marco; Villotti, Stefano; Torretta, Vincenzo

    2014-05-01

    In this paper an original energy recovery method from composting is analyzed. The integrated system exploits the heat available from the aerobic biochemical process in order to support the drying of sewage sludge, using a specific solar greenhouse. The aim is to tackle the problem of organic waste treatment, with specific regard to food waste. This is done by optimizing the energy consumption of the aerobic process of composting, using the heat produced to solve a second important waste management problem such as the sewage waste treatment. Energy and mass balances are presented in a preliminary feasibility study. Referring to a composting plant with a capacity of 15,000 t/y of food waste, the estimation of the power from recovered heat for the entire plant resulted about 42 kW. The results demonstrated that the energy recoverable can cover part of the heat necessary for the treatment of sludge generated by the population served by the composting plant (in terms of food waste and green waste collection). The addition of a renewable source such as solar energy could cover the residual energy demand. The approach is presented in detail in order for it to be replicated in other case studies or at full scale applications.

  13. Evaluation of (50)Cr, (52)Cr, (53)Cr, (54)Cr Neutron Cross Section Data for Energies up to 200 MeV

    SciTech Connect

    Pereslavtsev, P; Konobeyev, A; Fischer, U; Leal, Luiz C

    2011-01-01

    This work is on the evaluation of high energy general purpose neutron cross section data for the stable isotopes (50)Cr, (52)Cr, (53)Cr and (54)Cr. The GNASH and TALYS codes were applied for the nuclear reaction calculations that involve neutrons, protons, deuterons, tritons, hellions, alphas and photons in the energy range from 1 keV up to 200 MeV. The main focus of this work was on the quality of the evaluated data and their representation in ENDF files prepared in accordance with ENDF-6 format rules. Global optical model potentials were used for all particles in the calculations. The Geometry-Dependent Hybrid preequilibrium model (GDH) was included in TALYS for a better description of the complex particle emissions. The best fit of the experimental data was achieved by adjusting the nuclear model parameters. The data files include also newly evaluated resonance parameters and their covariances. Covariance data for all reaction channels were evaluated by the Unified Monte Carlo Approach. The new structure of the evaluated data files is discussed.

  14. MCNP calculations for container inspection with tagged neutrons

    NASA Astrophysics Data System (ADS)

    Boghen, G.; Donzella, A.; Filippini, V.; Fontana, A.; Lunardon, M.; Moretto, S.; Pesente, S.; Zenoni, A.

    2005-12-01

    We are developing an innovative tagged neutrons inspection system (TNIS) for cargo containers: the system will allow us to assay the chemical composition of suspect objects, previously identified by a standard X-ray radiography. The operation of the system is extensively being simulated by using the MCNP Monte Carlo code to study different inspection geometries, cargo loads and hidden threat materials. Preliminary simulations evaluating the signal and the signal over background ratio expected as a function of the system parameters are presented. The results for a selection of cases are briefly discussed and demonstrate that the system can operate successfully in different filling conditions.

  15. Developments for neutron-induced fission at IGISOL-4

    NASA Astrophysics Data System (ADS)

    Gorelov, D.; Penttilä, H.; Al-Adili, A.; Eronen, T.; Hakala, J.; Jokinen, A.; Kankainen, A.; Kolhinen, V. S.; Koponen, J.; Lantz, M.; Mattera, A.; Moore, I. D.; Pohjalainen, I.; Pomp, S.; Rakopoulos, V.; Reinikainen, J.; Rinta-Antila, S.; Simutkin, V.; Solders, A.; Voss, A.; Äystö, J.

    2016-06-01

    At the IGISOL-4 facility, neutron-rich, medium mass nuclei have usually been produced via charged particle-induced fission of natural uranium and thorium. Neutron-induced fission is expected to have a higher production cross section of the most neutron-rich species. Development of a neutron source along with a new ion guide continues to be one of the major goals since the commissioning of IGISOL-4. Neutron intensities at different angles from a beryllium neutron source have been measured in an on-line experiment with a 30 MeV proton beam. Recently, the new ion guide coupled to the neutron source has been tested as well. Details of the neutron source and ion guide design together with preliminary results from the first neutron-induced fission experiment at IGISOL-4 are presented in this report.

  16. Neutronic reactor

    DOEpatents

    Wende, Charles W. J.

    1976-08-17

    A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield.

  17. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Zinn, W.H.; Anderson, H.L.

    1958-09-16

    Means are presenied for increasing the reproduction ratio of a gaphite- moderated neutronic reactor by diminishing the neutron loss due to absorption or capture by gaseous impurities within the reactor. This means comprised of a fluid-tight casing or envelope completely enclosing the reactor and provided with a valve through which the casing, and thereby the reactor, may be evacuated of atmospheric air.

  18. Neutron tubes

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  19. Neutron source

    DOEpatents

    Cason, J.L. Jr.; Shaw, C.B.

    1975-10-21

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

  20. Development and preliminary evaluation of a behavioural HIV-prevention programme for teenage girls of Latino descent in the USA.

    PubMed

    Davidson, Tatiana M; Lopez, Cristina M; Saulson, Raelle; Borkman, April L; Soltis, Kathryn; Ruggiero, Kenneth J; de Arellano, Michael; Wingood, Gina M; Diclemente, Ralph J; Danielson, Carla Kmett

    2014-01-01

    National data suggests that teenage girls of Latino descent in the USA are disproportionately affected by HIV, with the US Centers for Disease Control and Prevention reporting the rate of new infections being approximately four times higher compared to White women of comparable age . This paper highlights the need for an effective single-sex HIV-prevention programme for teenage girls of Latino descent and describes the development and preliminary evaluation of Chicas Healing, Informing, Living and Empowering (CHILE), a culturally-tailored, HIV-prevention programme exclusively for teenage girls of Latino descent that was adapted from Sisters Informing, Healing, Living and Empowering (SiHLE), an evidence-based HIV- prevention program that is culturally tailored for African American young women. Theatre testing, a pre-testing methodology to assess consumer response to a demonstration of a product, was utilised to evaluate the relevance and utility of the HIV programme as well as opportunities for the integration of cultural constructs. Future directions for the evaluation of CHILE are discussed.

  1. Development and preliminary evaluation of a behavioural HIV prevention program for teenage girls of Latino descent in the USA

    PubMed Central

    Davidson, Tatiana M.; Lopez, Cristina M.; Saulson, Raelle; Borkman, April L.; Soltis, Kathryn; Ruggiero, Kenneth J.; de Arellano, Michael; Wingood, Gina M.; DiClemente, Ralph J.; Danielson, Carla Kmett

    2014-01-01

    National data suggests that teenage girls of Latino descent in the USA are disproportionately affected by HIV with the rate of new infections being approximately 4 times higher compared to White women of comparable age (Centers for Disease Control and Prevention 2013). This paper highlights the need for an effective single-sex HIV prevention program for teenage girls of Latino descent and describes the development and preliminary evaluation of Chicas Healing, Informing, Living and Empowering (CHILE), a culturally-tailored, HIV prevention programme exclusively for teenage girls of Latino descent that was adapted from Sisters Informing, Healing, Living, and Empowering (SiHLE), an evidence-based HIV prevention program that is culturally tailored for African American young women. Theatre testing, a pre-testing methodology to assess consumer response to a demonstration of a product, was utilised to evaluate the relevance and utility of the HIV program as well as opportunities for the integration of cultural constructs. Future directions for the evaluation of CHILE are discussed. PMID:24697607

  2. Neutron-fragment and Neutron-neutron Correlations in Low-energy Fission

    SciTech Connect

    Lestone, J.P.

    2016-01-15

    A computational method has been developed to simulate neutron emission from thermal-neutron induced fission of {sup 235}U and from spontaneous fission of {sup 252}Cf. Measured pre-emission mass-yield curves, average total kinetic energies and their variances, both as functions of mass split, are used to obtain a representation of the distribution of fragment velocities. Measured average neutron multiplicities as a function of mass split and their dependence on total kinetic energy are used. Simulations can be made to reproduce measured factorial moments of neutron-multiplicity distributions with only minor empirical adjustments to some experimental inputs. The neutron-emission spectra in the rest-frame of the fragments are highly constrained by ENDF/B-VII.1 prompt-fission neutron-spectra evaluations. The n-f correlation measurements of Vorobyev et al. (2010) are consistent with predictions where all neutrons are assumed to be evaporated isotropically from the rest frame of fully accelerated fragments. Measured n-f and n-n correlations of others are a little weaker than the predictions presented here. These weaker correlations could be used to infer a weak scission-neutron source. However, the effect of neutron scattering on the experimental results must be studied in detail before moving away from a null hypothesis that all neutrons are evaporated from the fragments.

  3. Alameda-Contra Costa Transit District (AC Transit) Fuel Cell Transit Buses: Preliminary Evaluation Results

    SciTech Connect

    Chandler, K.; Eudy, L.

    2007-03-01

    This report provides an evaluation of three prototype fuel cell-powered transit buses operating at AC Transit in Oakland, California, and six baseline diesel buses similar in design to the fuel cell buses.

  4. Topaz II preliminary safety assessment

    NASA Astrophysics Data System (ADS)

    Marshall, Albert C.; Standley, Vaughn; Voss, Susan S.; Haskin, Eric

    1993-01-01

    The Strategic Defense Initiative Organization (SDIO) decided to investigate the possibility of launching a Russian Topaz II space nuclear power system. A preliminary safety assessment was conducted to determine whether or not a space mission could be conducted safely and within budget constraints. As part of this assessment, a safety policy and safety functional requirements were developed to guide both the safety assessment and future Topaz II activities. A review of the Russian flight safety program was conducted and documented. Our preliminary safety assessment included a top level event tree, neutronic analysis of normal and accident configurations, an evaluation of temperature coefficients of reactivity, a reentry and disposal analysis, and analysis of postulated launch abort impact accidents, and an analysis of postulated propellant fire and explosion accidents. Based on the assessment, it appears that it will be possible to safely launch the Topaz II system in the U.S. with some possible system modifications. The principal system modifications will probably include design changes to preclude water flooded criticality and to assure intact reentry.

  5. Topaz II preliminary safety assessment

    SciTech Connect

    Marshall, A.C. ); Standley, V. ); Voss, S.S. ); Haskin, E. . Dept. of Chemical and Nuclear Engineering)

    1992-01-01

    The Strategic Defense Initiative Organization (SDIO) decided to investigate the possibility of launching a Russian Topaz 11 space nuclear power system. A preliminary safety assessment was conducted to determine whether or not a space mission could be conducted safely and within budget constraints. As part of this assessment, a safety policy and safety functional requirements were developed to guide both the safely assessment and future Topaz II activities. A review of the Russian flight safety program was conducted and documented. Our preliminary safety assessment included a top level event tree, neutronic analysis of normal and accident configurations, an evaluation of temperature coefficients of reactivity, a reentry and disposal analysis, and analysis of postulated launch abort impact accidents, and an analysis of postulated propellant fire and explosion accidents. Based on the assessment, it appears that it will be possible to safely launch the Topaz II system in the US with some possible system modifications. The principal system modifications will probably include design changes to preclude water flooded criticality and to assure intact reentry.

  6. Topaz II preliminary safety assessment

    SciTech Connect

    Marshall, A.C. ); Standley, V. ); Voss, S.S. ); Haskin, E. )

    1993-01-10

    The Strategic Defense Initiative Organization (SDIO) decided to investigate the possibility of launching a Russian Topaz II space nuclear power system. A preliminary safety assessment was conducted to determine whether or not a space mission could be conducted safely and within budget constraints. As part of this assessment, a safety policy and safety functional requirements were developed to guide both the safety assessment and future Topaz II activities. A review of the Russian flight safety program was conducted and documented. Our preliminary safety assessment included a top level event tree, neutronic analysis of normal and accident configurations, an evaluation of temperature coefficients of reactivity, a reentry and disposal analysis, and analysis of postulated launch abort impact accidents, and an analysis of postulated propellant fire and explosion accidents. Based on the assessment, it appears that it will be possible to safely launch the Topaz II system in the U.S. with some possible system modifications. The principal system modifications will probably include design changes to preclude water flooded criticality and to assure intact reentry.

  7. Preliminary evaluation of effects of best management practices in the Black Earth Creek, Wisconsin, priority watershed

    USGS Publications Warehouse

    Walker, J.F.; Graczyk, D.J.; Olem, H.

    1993-01-01

    Nonpoint-source contamination accounts for a substantial part of the water quality problems in many watersheds. The Wisconsin Nonpoint Source Water Pollution Abatement Program provides matching money for voluntary implementation of various best management practices (BMPs). The effectiveness of BMPs on a drainage-basin scale has not been adequately assessed in Wisconsin by use of data collected before and after BMP implementation. The U.S. Geological Survey, in cooperation with the Wisconsin Department of Natural Resources, monitored water quality in the Black Earth Creek watershed in southern Wisconsin from October 1984 through September 1986 (pre-BMP conditions). BMP implementation began during the summer of 1989 and is planned to continue through 1993. Data collection resumed in fall 1989 and is intended to provide information during the transitional period of BMP implementation (1990-93) and 2 years of post-BMP conditions (1994-95). Preliminary results presented for two subbasins in toe Black Earth Creek watershed (Brewery and Garfoot Creeks) are based on data collected during pre-BMP conditions and the first 3 years of the transitional period. The analysis includes the use of regressions to control for natural variability in the data and, hence, enhance the ability to detect changes. Data collected to date (1992) indicate statistically significant differences in storm mass transport of suspended sediment and ammonia nitrogen at Brewery Creek. The central tendency of the regression residuals has decreased with the implementation of BMPs; hence, the improvement in water quality in the Brewery Creek watershed is likely a result of BMP implementation. Differences in storm mass transport at Garfoot Creek were not detected, primarily because of an insufficient number of storms in the transitional period. As practice implementation continues, the additional data will be used to determine the level of management which results in significant improvements in water

  8. A Preliminary Evaluation of Supersonic Transport Category Vehicle Operations in the National Airspace System

    NASA Technical Reports Server (NTRS)

    Underwood, Matthew C.; Guminsky, Michael D.

    2015-01-01

    Several public sector businesses and government agencies, including the National Aeronautics and Space Administration are currently working on solving key technological barriers that must be overcome in order to realize the vision of low-boom supersonic flights conducted over land. However, once these challenges are met, the manner in which this class of aircraft is integrated in the National Airspace System may become a potential constraint due to the significant environmental, efficiency, and economic repercussions that their integration may cause. Background research was performed on historic supersonic operations in the National Airspace System, including both flight deck procedures and air traffic controller procedures. Using this information, an experiment was created to test some of these historic procedures in a current-day, emerging Next Generation Air Transportation System (NextGen) environment and observe the interactions between commercial supersonic transport aircraft and modern-day air traffic. Data was gathered through batch simulations of supersonic commercial transport category aircraft operating in present-day traffic scenarios as a base-lining study to identify the magnitude of the integration problems and begin the exploration of new air traffic management technologies and architectures which will be needed to seamlessly integrate subsonic and supersonic transport aircraft operations. The data gathered include information about encounters between subsonic and supersonic aircraft that may occur when supersonic commercial transport aircraft are integrated into the National Airspace System, as well as flight time data. This initial investigation is being used to inform the creation and refinement of a preliminary Concept of Operations and for the subsequent development of technologies that will enable overland supersonic flight.

  9. Design and preliminary evaluation of a self-steering, pneumatically driven colonoscopy robot.

    PubMed

    Dehghani, Hossein; Welch, C Ross; Pourghodrat, Abolfazl; Nelson, Carl A; Oleynikov, Dmitry; Dasgupta, Prithviraj; Terry, Benjamin S

    2017-04-01

    Colonoscopy is a diagnostic procedure to detect pre-cancerous polyps and tumours in the colon, and is performed by inserting a long tube equipped with a camera and biopsy tools. Despite the medical benefits, patients undergoing this procedure often complain about the associated pain and discomfort. This discomfort is mostly due to the rough handling of the tube and the creation of loops during the insertion. The overall goal of this work is to minimise the invasiveness of traditional colonoscopy. In pursuit of this goal, this work presents the development of a semi-autonomous colonoscopic robot with minimally invasive locomotion. The proposed robotic approach allows physicians to concentrate mainly on the diagnosis rather than the mechanics of the procedure. In this paper, an innovative locomotion approach for robotic colonoscopy is addressed. Our locomotion approach takes advantage of longitudinal expansion of a latex tube to propel the robot's tip along the colon. This soft and compliant propulsion mechanism, in contrast to minimally invasive mechanisms used in, for example, inchworm-like robots, has shown promising potential. In the preliminary ex vivo experiments, the robot successfully advanced 1.5 metres inside an excised curvilinear porcine colon with average speed of 28 mm/s, and was capable of traversing bends up to 150 degrees. The robot creates less than 6 N of normal force at its tip when it is pressurised with 90 kPa. This maximum force generates pressure of 44.17 mmHg at the tip, which is significantly lower than safe intraluminal human colonic pressure of 80 mmHg. The robot design inherently prevents loop formation in the colon, which is recognised as the main cause of post procedural pain in patients. Overall, the robot has shown great promise in an ex vivo experimental setup. The design of an autonomous control system and in vivo experiments are left as future work.

  10. A Preliminary Design of a Calibration Chamber for Evaluating the Stability of Unsaturated Soil Slope

    NASA Astrophysics Data System (ADS)

    Hsu, H.-H.

    2012-04-01

    The unsaturated soil slopes, which have ground water tables and are easily failure caused by heavy rainfalls, are widely distributed in the arid and semi-arid areas. For analyzing the stability of slope, in situ tests are the direct methods to obtain the test site characteristics. The cone penetration test (CPT) is a popular in situ test method. Some of the CPT empirical equations established from calibration chamber tests. The CPT performed in calibration chamber was commonly used clean quartz sand as testing material in the past. The silty sand is observed in many actual slopes. Because silty sand is relatively compressible than quartz sand, it is not suitable to apply the correlations between soil properties and CPT results built from quartz sand to silty sand. The experience on CPT calibration in silty sand has been limited. CPT calibration tests were mostly performed in dry or saturated soils. The condition around cone tip during penetration is assumed to be fully drained or fully undrained, yet it was observed to be partially drained for unsaturated soils. Because of the suction matrix has a great effect on the characteristics of unsaturated soils, they are much sensitive to the water content than saturated soils. The design of an unsaturated calibration chamber is in progress. The air pressure is supplied from the top plate and the pore water pressure is provided through the high air entry value ceramic disks located at the bottom plate of chamber cell. To boost and uniform distribute the unsaturated effect, four perforated burettes are installed onto the ceramic disks and stretch upwards to the midheight of specimen. This paper describes design concepts, illustrates this unsaturated calibration chamber, and presents the preliminary test results.

  11. A preliminary evaluation of a combined tire- and refuse-derived fuel (TDF-RDF)

    SciTech Connect

    Stessel, R.I.; Amari, T.; Themelis, N.J.; Wearnick, I.K.

    1999-07-01

    In dense urban areas of the US, it is now becoming clear that waste management is far from economically-optimum. Even with the popularity of inexpensive land disposal, hauling and recycling costs are driving up the average waste bill. An historic option has been refuse-derived fuel, or RDF. Difficulties included low energy content and difficulty obtaining uniformity. Today, many resource-recovery technologies used in RDF are finding their way into materials recovery facilities (MRFs), some of which are reviving the automated processing of waste. Any MRF, automated or not, will have residue streams. Currently, one of the most significant problems is waste tires. Local options are difficult to locate in dense urban areas. As fuels, tires typically have energy contents considerably above those for which most solid-fuel combustors are designed, leading to thermal imbalances and various forms of failure. This paper suggests a new fuel that can be either co-fired with coal, or used in its own right in a combustor primarily designed for coal: TDF-RDF. A preliminary examination is undertaken of thermal and emissions characteristics, and possible costs for a few applications of the fuel. Immediately, TDF is already cleaner-burning than many coals, even in sulfur emissions. RDF has been widely-regarded as being similarly cleanly. Posited MRF residue streams should be still cleaner, and more consistent, than RDF. Overall, there is quite a potential for developing a fuel that would allow old coal powerplants in historic urban centers to be better neighbors, while helping with a few problems in municipal waste management.

  12. Evaluation of Passive Multilayer Cloud Detection Using Preliminary CloudSat and CALIPSO Cloud Profiles

    NASA Astrophysics Data System (ADS)

    Minnis, P.; Sun-Mack, S.; Chang, F.; Huang, J.; Nguyen, L.; Ayers, J. K.; Spangenberg, D. A.; Yi, Y.; Trepte, C. R.

    2006-12-01

    During the last few years, several algorithms have been developed to detect and retrieve multilayered clouds using passive satellite data. Assessing these techniques has been difficult due to the need for active sensors such as cloud radars and lidars that can "see" through different layers of clouds. Such sensors have been available only at a few surface sites and on aircraft during field programs. With the launch of the CALIPSO and CloudSat satellites on April 28, 2006, it is now possible to observe multilayered systems all over the globe using collocated cloud radar and lidar data. As part of the A- Train, these new active sensors are also matched in time ad space with passive measurements from the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Microwave Scanning Radiometer - EOS (AMSR-E). The Clouds and the Earth's Radiant Energy System (CERES) has been developing and testing algorithms to detect ice-over-water overlapping cloud systems and to retrieve the cloud liquid path (LWP) and ice water path (IWP) for those systems. One technique uses a combination of the CERES cloud retrieval algorithm applied to MODIS data and a microwave retrieval method applied to AMSR-E data. The combination of a CO2-slicing cloud retireval technique with the CERES algorithms applied to MODIS data (Chang et al., 2005) is used to detect and analyze such overlapped systems that contain thin ice clouds. A third technique uses brightness temperature differences and the CERES algorithms to detect similar overlapped methods. This paper uses preliminary CloudSat and CALIPSO data to begin a global scale assessment of these different methods. The long-term goals are to assess and refine the algorithms to aid the development of an optimal combination of the techniques to better monitor ice 9and liquid water clouds in overlapped conditions.

  13. Five-Kilometers Time Trial: Preliminary Validation of a Short Test for Cycling Performance Evaluation

    PubMed Central

    Dantas, Jose Luiz; Pereira, Gleber; Nakamura, Fabio Yuzo

    2015-01-01

    Background: The five-kilometer time trial (TT5km) has been used to assess aerobic endurance performance without further investigation of its validity. Objectives: This study aimed to perform a preliminary validation of the TT5km to rank well-trained cyclists based on aerobic endurance fitness and assess changes of the aerobic endurance performance. Materials and Methods: After the incremental test, 20 cyclists (age = 31.3 ± 7.9 years; body mass index = 22.7 ± 1.5 kg/m2; maximal aerobic power = 360.5 ± 49.5 W) performed the TT5km twice, collecting performance (time to complete, absolute and relative power output, average speed) and physiological responses (heart rate and electromyography activity). The validation criteria were pacing strategy, absolute and relative reliability, validity, and sensitivity. Sensitivity index was obtained from the ratio between the smallest worthwhile change and typical error. Results: The TT5km showed high absolute (coefficient of variation < 3%) and relative (intraclass coefficient correlation > 0.95) reliability of performance variables, whereas it presented low reliability of physiological responses. The TT5km performance variables were highly correlated with the aerobic endurance indices obtained from incremental test (r > 0.70). These variables showed adequate sensitivity index (> 1). Conclusions: TT5km is a valid test to rank the aerobic endurance fitness of well-trained cyclists and to differentiate changes on aerobic endurance performance. Coaches can detect performance changes through either absolute (± 17.7 W) or relative power output (± 0.3 W.kg-1), the time to complete the test (± 13.4 s) and the average speed (± 1.0 km.h-1). Furthermore, TT5km performance can also be used to rank the athletes according to their aerobic endurance fitness. PMID:26448846

  14. Sewage sludge drying by energy recovery from OFMSW composting: Preliminary feasibility evaluation

    SciTech Connect

    Rada, Elena Cristina; Ragazzi, Marco; Villotti, Stefano; Torretta, Vincenzo

    2014-05-01

    Highlights: • The aim is to support the drying of sewage sludge, using a solar greenhouse. • The system allows the exploitation of heat available from OFMSW aerobic process. • Another aim is to face the problem of OFMSW treatment, in particular food waste. • Energy and mass balances are presented for a case study. - Abstract: In this paper an original energy recovery method from composting is analyzed. The integrated system exploits the heat available from the aerobic biochemical process in order to support the drying of sewage sludge, using a specific solar greenhouse. The aim is to tackle the problem of organic waste treatment, with specific regard to food waste. This is done by optimizing the energy consumption of the aerobic process of composting, using the heat produced to solve a second important waste management problem such as the sewage waste treatment. Energy and mass balances are presented in a preliminary feasibility study. Referring to a composting plant with a capacity of 15,000 t/y of food waste, the estimation of the power from recovered heat for the entire plant resulted about 42 kW. The results demonstrated that the energy recoverable can cover part of the heat necessary for the treatment of sludge generated by the population served by the composting plant (in terms of food waste and green waste collection). The addition of a renewable source such as solar energy could cover the residual energy demand. The approach is presented in detail in order for it to be replicated in other case studies or at full scale applications.

  15. Evaluating a Contribution of the Knock-on Deuterons to the Neutron Yield in the Experiments with Weakly Collisional Plasma Jets (Part 2)

    SciTech Connect

    Ryutov, D. D.

    2015-12-08

    Part 1 of this note considered the kinematics of large-angle scattering (LAS) of the deuterons on the counter-streaming carbon ions, with both flows having the same velocity V. Due to a large mass ratio mC/mD, the backscattered deuterons have high velocity of up to (24/7)V. This significantly increases the cross-section for the neutron production in the collisions between the back-scattered and incoming deuterons and may provide significant contribution to the total neutron yield, despite the smallness of a large-angle Coulomb cross-section. This effect becomes particularly important when only one of the colliding streams is made of CD, whereas the other stream is made of CH. Part 1 evaluated the neutron yield produced by this mechanism and have found that its relative role increases for higher plasma densities and lower velocities. Part 2 discusses signatures of this effect which can be used to identify it experimentally and also discusses in some more detail its spatio-temporal characteristics. It goes without saying that a complete quantitative assessment should be based on numerical simulations accounting for the large-angle scattering.

  16. Design of a neutron-TPC prototype and its performance evaluation based on an alpha-particle test

    NASA Astrophysics Data System (ADS)

    Huang, Meng; Li, Yu-Lan; Niu, Li-Bo; Li, Jin; Deng, Zhi; He, Li; Zhang, Hong-Yan; Cheng, Xiao-Lei; Fu, Jian-Qiang; Li, Yuan-Jing

    2015-08-01

    A neutron-TPC (nTPC) is being developed for use as a fast neutron spectrometer in the fields of nuclear physics, nuclear reactor operation monitoring, and thermo-nuclear fusion plasma diagnostics. An nTPC prototype based on a GEM-TPC (Time Projection Chamber with Gas Electron Multiplier amplification) has been assembled and tested using argon-hydrocarbon mixture as the working gas. By measuring the energy deposition of the recoil proton in the sensitive volume and the angle of the proton track, the incident neutron energy can be deduced. A Monte Carlo simulation was carried out to analyze the parameters affecting the energy resolution of the nTPC, and gave an optimized resolution under ideal conditions. An alpha particle experiment was performed to verify its feasibility, and to characterize its performance, including energy resolution and spatial resolution. Based on the experimental measurement and analysis, the energy resolution (FWHM) of the nTPC prototype is predicted to be better than 3.2% for 5 MeV incident neutrons, meeting the performance requirement (FWHM<5%) for the nTPC prototype.

  17. Studies on osteoporosis. V. Comparison of methods of evaluation of osteoporosis and study of chromosome changes induced by neutron activation

    SciTech Connect

    Robin, J.C.; Sirianni, S.R.; Pragay, D.A.; Ambrus, J.L.

    1981-01-01

    In vivo activation analysis was compared with ashing and atomic absorption spectrophotometry for the determination of total skeletal calcium content in mice. The results were close to identical. The possible mutagenic-carcinogenic effect of repeated exposure to whole body neutron irradiation was studied by chromosome analysis. Under the conditions of these experiments, no significant chromosome changes were seen.

  18. Evaluation of a digital data acquisition system and optimization of n-{gamma} discrimination for a compact neutron spectrometer

    SciTech Connect

    Giacomelli, L.; Zimbal, A.; Reginatto, M.; Tittelmeier, K.

    2011-01-15

    A compact NE213 liquid scintillation neutron spectrometer with a new digital data acquisition (DAQ) system is now in operation at the Physikalisch-Technische Bundesanstalt (PTB). With the DAQ system, developed by ENEA Frascati, neutron spectrometry with high count rates in the order of 5x10{sup 5} s{sup -1} is possible, roughly an order of magnitude higher than with an analog acquisition system. To validate the DAQ system, a new data analysis code was developed and tests were done using measurements with 14-MeV neutrons made at the PTB accelerator. Additional analysis was carried out to optimize the two-gate method used for neutron and gamma (n-{gamma}) discrimination. The best results were obtained with gates of 35 ns and 80 ns. This indicates that the fast and medium decay time components of the NE213 light emission are the ones that are relevant for n-{gamma} discrimination with the digital acquisition system. This differs from what is normally implemented in the analog pulse shape discrimination modules, namely, the fast and long decay emissions of the scintillating light.

  19. Evaluation of a digital data acquisition system and optimization of n-γ discrimination for a compact neutron spectrometer.

    PubMed

    Giacomelli, L; Zimbal, A; Reginatto, M; Tittelmeier, K

    2011-01-01

    A compact NE213 liquid scintillation neutron spectrometer with a new digital data acquisition (DAQ) system is now in operation at the Physikalisch-Technische Bundesanstalt (PTB). With the DAQ system, developed by ENEA Frascati, neutron spectrometry with high count rates in the order of 5×10(5) s(-1) is possible, roughly an order of magnitude higher than with an analog acquisition system. To validate the DAQ system, a new data analysis code was developed and tests were done using measurements with 14-MeV neutrons made at the PTB accelerator. Additional analysis was carried out to optimize the two-gate method used for neutron and gamma (n-γ) discrimination. The best results were obtained with gates of 35 ns and 80 ns. This indicates that the fast and medium decay time components of the NE213 light emission are the ones that are relevant for n-γ discrimination with the digital acquisition system. This differs from what is normally implemented in the analog pulse shape discrimination modules, namely, the fast and long decay emissions of the scintillating light.

  20. Fast, quantitative, and nondestructive evaluation of hydrided LWR fuel cladding by small angle incoherent neutron scattering of hydrogen

    SciTech Connect

    Yan, Y.; Qian, S.; Littrell, K.; Parish, C. M.; Plummer, L. K.

    2015-02-13

    A non-destructive neutron scattering method to precisely measure the uptake of hydrogen and the distribution of hydride precipitates in light water reactor (LWR) fuel cladding was developed. Zircaloy-4 cladding used in commercial LWRs was used to produce hydrided specimens. The hydriding apparatus consists of a closed stainless steel vessel that contains Zr alloy specimens and hydrogen gas. Following hydrogen charging, the hydrogen content of the hydrided specimens was measured using the vacuum hot extraction method, by which the samples with desired hydrogen concentration were selected for the neutron study. Optical microscopy shows that our hydriding procedure results in uniform distribution of circumferential hydrides across the wall. Small angle neutron incoherent scattering was performed in the High Flux Isotope Reactor at Oak Ridge National Laboratory. This study demonstrates that the hydrogen in commercial Zircaloy-4 cladding can be measured very accurately in minutes by this nondestructive method over a wide range of hydrogen concentrations from a very small amount ( 20 ppm) to over 1000 ppm. The hydrogen distribution in a tube sample was obtained by scaling the neutron scattering rate with a factor determined by a calibration process using standard, destructive direct chemical analysis methods on the specimens. This scale factor will be used in future tests with unknown hydrogen concentrations, thus providing a nondestructive method for absolute hydrogen concentration determination.

  1. Fast, quantitative, and nondestructive evaluation of hydrided LWR fuel cladding by small angle incoherent neutron scattering of hydrogen

    DOE PAGES

    Yan, Y.; Qian, S.; Littrell, K.; ...

    2015-02-13

    A non-destructive neutron scattering method to precisely measure the uptake of hydrogen and the distribution of hydride precipitates in light water reactor (LWR) fuel cladding was developed. Zircaloy-4 cladding used in commercial LWRs was used to produce hydrided specimens. The hydriding apparatus consists of a closed stainless steel vessel that contains Zr alloy specimens and hydrogen gas. Following hydrogen charging, the hydrogen content of the hydrided specimens was measured using the vacuum hot extraction method, by which the samples with desired hydrogen concentration were selected for the neutron study. Optical microscopy shows that our hydriding procedure results in uniform distributionmore » of circumferential hydrides across the wall. Small angle neutron incoherent scattering was performed in the High Flux Isotope Reactor at Oak Ridge National Laboratory. This study demonstrates that the hydrogen in commercial Zircaloy-4 cladding can be measured very accurately in minutes by this nondestructive method over a wide range of hydrogen concentrations from a very small amount ( 20 ppm) to over 1000 ppm. The hydrogen distribution in a tube sample was obtained by scaling the neutron scattering rate with a factor determined by a calibration process using standard, destructive direct chemical analysis methods on the specimens. This scale factor will be used in future tests with unknown hydrogen concentrations, thus providing a nondestructive method for absolute hydrogen concentration determination.« less

  2. Conducting Polymers for Neutron Detection

    SciTech Connect

    Kimblin, Clare; Miller, Kirk; Vogel, Bob; Quam, Bill; McHugh, Harry; Anthony, Glen; Mike, Grover

    2007-12-01

    Conjugated polymers have emerged as an attractive technology for large-area electronic applications. As organic semiconductors, they can be used to make large-area arrays of diodes or transistors using fabrication techniques developed for polymer coatings, such as spraying and screen-printing. We have demonstrated both neutron and alpha detection using diodes made from conjugated polymers and have done preliminary work to integrate a boron carbide layer into the conventional polymer device structure to capture thermal neutrons. The polymer devices appear to be insensitive to gamma rays, due to their small physical thickness and low atomic number.

  3. Exploring neutron detection with HADES

    NASA Astrophysics Data System (ADS)

    Chlad, L.

    2016-08-01

    The HADES experiment at GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt (Germany) is fixed target experiment using SIS-18 accelerator to study collisions of protons, heavy-ions or secondary pions with target nuclei. HADES was designed and provides very accurate measurement of di-electrons and charged hadrons. The pion induced reactions provide unique opportunity to study exclusive reactions with neutrons in the final state. Using the inclusive channel π- + p → π- + π+ n we can optimize the selection criteria for neutron hits in TOF/RPC. Dedicated simulations are compared with preliminary results of real data analysis for reaction channels with two neutral particles in the final state.

  4. Development and Preliminary Evaluation of Aryl Ester Boundary Additives for Perfluoropolyethers

    NASA Technical Reports Server (NTRS)

    Williams, John R.; Feuchter, Debra K.; Jones, William R., Jr.

    1994-01-01

    A series of additives were developed for evaluation as boundary lubrication enhancers for perfluoropolyethers. They are composed of a hydrocarbon aryl component (for lubrication improvement) and a fluorinated side chain (for solubility enhancement). The two moieties are joined by an ester linkage. Five boundary additives were evaluated in a perfluoropolyether basestock (Fomblin Z25) using a specially designed four-ball apparatus. Additives were evaluated at a one wt percent concentration. Conditions included: an atmosphere of dry air at atmospheric pressure, a 200N load, a speed of 100 rpm, room temperature, and 440C stainless steel specimens. Two monoesters, 2,4,6-trimethyl E2 and H5PDFO yielded wear rate reductions of approximately 60 and 35 percent, respectively. One diester, H4(E2)(sub 2), had no activity, while two other diesters (a diester of bisphenol A and H4(E4)(sub 2)) were pro-wear.

  5. Preliminary evaluation of spectral, normal and meteorological crop stage estimation approaches

    NASA Technical Reports Server (NTRS)

    Cate, R. B.; Artley, J. A.; Doraiswamy, P. C.; Hodges, T.; Kinsler, M. C.; Phinney, D. E.; Sestak, M. L. (Principal Investigator)

    1980-01-01

    Several of the projects in the AgRISTARS program require crop phenology information, including classification, acreage and yield estimation, and detection of episodal events. This study evaluates several crop calendar estimation techniques for their potential use in the program. The techniques, although generic in approach, were developed and tested on spring wheat data collected in 1978. There are three basic approaches to crop stage estimation: historical averages for an area (normal crop calendars), agrometeorological modeling of known crop-weather relationships agrometeorological (agromet) crop calendars, and interpretation of spectral signatures (spectral crop calendars). In all, 10 combinations of planting and biostage estimation models were evaluated. Dates of stage occurrence are estimated with biases between -4 and +4 days while root mean square errors range from 10 to 15 days. Results are inconclusive as to the superiority of any of the models and further evaluation of the models with the 1979 data set is recommended.

  6. Evaluation of cross sections for neutron-induced reactions in sodium. [10/sup -5/ eV to 20 MeV

    SciTech Connect

    Larson, D.C.

    1980-09-01

    An evaluation of the neutron-induced cross sections of /sup 23/Na has been done for the energy range from 10/sup -5/ eV to 20 MeV. All significant cross sections are given, including differential cross sections for production of gamma rays. The recommended values are based on experimental data where available, and use results of a consistent model code analysis of available data to predict cross sections where there are no experimental data. This report describes the evaluation that was submitted to the Cross Section Evaluation Working Group (CSEWG) for consideration as a part of the Evaluated Nuclear Data File, Version V, and subsequently issued as MAT 1311. 126 references, 130 figures, 14 tables.

  7. Preliminary evaluation of the air and fuel specific-impulse characteristics of several potential ram-jet fuels IV : hydrogen, a-methylnaphthalene, and carbon / Benson E. Gammon

    NASA Technical Reports Server (NTRS)

    Gammon, Benson E

    1951-01-01

    A preliminary analytical evaluation of the air and fuel specific-impulse characteristics of hydrogen, a-methylnapthalene, and graphite carbon has been made. Adiabatic constant-pressure combustion flame temperatures for each fuel at several equivalence ratios were calculated for an initial air temperature of 560 degrees R and a pressure of 2 atmospheres.

  8. Description and Preliminary Evaluation of a Curriculum for Teaching Conversational Skills to Children with High-Functioning Autism and Other Social Cognition Challenges

    ERIC Educational Resources Information Center

    Müller, Eve; Cannon, Lynn R.; Kornblum, Courtney; Clark, Jonna; Powers, Michal

    2016-01-01

    Purpose: The purpose of this clinical focus article is to provide (a) a detailed description of a school-based intervention designed to teach children with high-functioning autism spectrum disorders (HF-ASDs) and other social cognition challenges both the "how" and the "why" of conversation and (b) a preliminary evaluation of…

  9. Design and evaluation of a patient website to reduce crowding in emergency departments: a preliminary study.

    PubMed

    Schiro, Jessica; Marcilly, Romaric; Leroy, Nicolas; Wawrzyniak, Clément; Martinot, Alain; Pelayo, Sylvia

    2015-01-01

    The study aims to identify the information useful to support a patients' EDs' choice in order to design a patient Web-based system. For that purpose, a focus group and a formative user test have been performed. The results show that five types of information can be relevant. The spontaneous favored information is the "distance" to EDs. The "Wait time", that is sanctified in literature, is only used in a second time. A larger summative evaluation should be planned to evaluate and validate the befits of this kind of tool.

  10. Preliminary Evaluation of Greases for Space Mechanisms Using a Vacuum Spiral Orbit Tribometer

    NASA Technical Reports Server (NTRS)

    Marchetti, Mario; Jones, William R., Jr.; Street, Kenneth W.; Pepper, Stephen V.; Jansen, Mark J.

    2001-01-01

    Most currently used greases for space applications are based on perfluoropolyalkylethers (PFPE) and multiply alkylated cyclopentane (MAC) oils. Evaluation of the greases includes outgassing properties, rheological behavior, and particularly the ability to create EHL films under conditions as close as possible to an actual application. A spiral orbit tribometer (SOT) has been developed to conduct accelerated tests under realistic conditions. The SOT was employed to evaluate two greases used in space mechanisms: a PFPE oil with polytetrafluoroethylene (PTFE) thickener, and a multiply alkylated cyclopentane oil with n-octadecylterephthalamate soap. The results from the greases are in agreement with results previously obtained with the base oils.

  11. Formative usability evaluation of a web-based insulin self-titration system: preliminary results.

    PubMed

    Gude, Wouter T; Simon, Airin C R; Peute, Linda W P; Holleman, Frits; Hoekstra, Joost B L; Peek, Niels; Jaspers, Monique W M

    2012-01-01

    We developed a web-based system supporting patients in insulin self-titration and their caregivers in monitoring patients' self-management activities. Since usability flaws could cause user attrition and compromise patient safety, we evaluated the system's usability prior to its implementation in practice. Two pairs of researchers conducted cognitive walkthrough sessions and identified 81 unique usability problems, including four with a potential impact on patient safety. Usability evaluations could reveal many usability problems and allow solving the problems while avoiding user attrition and potential adverse patient events.

  12. Preliminary Evaluations Related to the Ranges of Hematological and Biochemical Variables in Hospitalized Patients with Stroke

    PubMed Central

    Chitsaz, Ahmad; Tolou-Ghamari, Zahra; Ashtari, Fereshteh

    2013-01-01

    Background: According to the international reports, brain stroke is the main reason of death and disability. In ischemic stroke, early and precise classification of patients who may profit from conflicting finest therapeutic interference is necessary if enhanced effects in terms of survival are to be talented. Due to uncomplicated, easy performance, and inexpensive method the aim of this preliminary study was to investigate changes related to biochemical and hematological variables in patients with stroke. Methods: A cross-sectional study located at the neurology ward of the Ayatolah Kashani and Alzahra Hospitals’ (conducted to Isfahan Neurosciences Research Center) was carried out on fifty patients (females; n = 20 and males; n = 30) between April 1, 2012 and September 31, 2012. The data from subjects’ records were taken for analyzing variables. The statistical analysis of d-base was performed using (SPSS) for windows. Results: Analysis of available data showed that with a mean of 182.4 mg/dl, blood sugar (BS) ranged from 75 to 300 mg/dl (n = 15/50). The changes in hemoglobin (Hgb) (mean 4.6 g/dl, n = 27/50), platelet (mean 210, 653/mm3, n = 26/50) and lymphocyte (Lymph) (mean 37, n = 26/50) seems to be significant. The mean age of females was 76 years (ranged 46-93 years). The mean age of males was 70 years (ranged 31-90 years). Information related to previous drug history was available only in 24 patients. In 5 out of 22 cases ischemic heart disease (IHD) were positive. In 8 out of 29 cases, diabetes mellitus was positive. In 5 out of 28 cases, hypertension (HTN) was positive. In the four patients both IHD and HTN were positive. Conclusions: Any considerable alter in patients’ biochemical and hematological figures (BS, Hgb, Plt and Lymph) may necessitate further attention related to inter- and intra-individual variability in clinical supervision and drug's assortment. Therefore, success in treatment could be achieved by the close management of clinical

  13. Hyperacuity test to evaluate vision through dense cataracts: research preliminary to a clinical study in India

    NASA Astrophysics Data System (ADS)

    Enoch, Jay M.; Giraldez, Maria J.; Huang, Doahua; Hirose, Hiroshi; Knowles, Richard A.; Namperumalsamy, P.; LaBree, Lauri; Azen, Stanley P.

    1995-03-01

    Using high luminance point-of-light stimuli, Vernier judgments can be made in the presence of markedly degraded retinal imagery. Without coaching, observers perform center-of-gravity assessments of relative locations of degraded point images. We seek to defined, presurgery, individuals who will derive the most benefit from advanced cataract removal (a form of triage), and to determine which of two cataractous eyes has the better postsurgical visual prognosis. There are incredible and growing backlogs of patients with severe cataracts (and other dense media opacities) in the developing world, and generally, limited resources are available for provision of health care. Postcataract surgical failure rates for good visual function are often high, and only one eye is operated on in over 95% of indigent patients treated. Prior to initiating advanced studies in the developing world, at Berkeley we conducted preliminary research on Vernier acuity test techniques on normal adult subjects. We sought to determine the number of repeat trials necessary; to compare a two-point and a three-point Vernier display; to determine the shape of the measured response function at large gap separations between test points (required when testing advanced cataract patients); to assess the effect(s) of a broad range of uncorrected refractive errors on outcomes; and to consider means to minimize refraction-based errors. From these and prior data and analyses, we defined a protocol for use in the developing world. Using a newly designed and rugged precision instrument, these tests were repeated on an advanced cataract population at Aravind Eye Hospital in Madurai, India. Although we had much prior experience in India, the initial protocol required major revision on site. Necessary changes in test methods and analytical approaches were made, and next stages in this program were planned. And a new and simple gap `visual acuity' (gap `VA') test was added to the protocol, which greatly facilitated

  14. Analyzing of the Die Away Curve of the Msl Dynamic Albedo of Neutrons (dan) Instrument

    NASA Astrophysics Data System (ADS)

    Varenikov, A.; Jun, I.; Litvak, M. L.

    2012-12-01

    The Dynamic Albedo of Neutrons (DAN) is flown on board Mars Science Laboratory (MSL) to provide measurements of the dynamic albedo of thermal and epithermal neutrons induced by a pulse 14 MeV neutron generator. The DAN instrument consists of pulse neutron generator (DAN/PNG) electrically and logically combined with neutron detection system (DAN/DE). The major science objective of DAN instrument is to detect and provide quantitative estimates of the hydrogen content in the sub-surface layer of Mars. The amplitude and shape of the die-away time profile strongly depends on the content, depth and geometry distribution of water ice/bound layer. Die-away curves of thermal neutrons are simulated using a Monte Carlo transport code (MCNPX) for a homogeneous model of regolith with different contents of water. Tw different cases were considered in the initial simulations: single layered model and double layered model. In the first case, the sub-surface is modelled as a homogeneous single layer with different water contents. The preliminary results show that DAN could measure the water content as low as 0.1-0.2 weight %. The second case includes the sub-surface described by two layers. It is used to evaluate the DAN sensitivity to detect water depth (where the bottom layer is richer in water content than the upper layer).

  15. Analysis of the Nuclear Structure of 186 Re Using Neutron-Induced Reactions

    NASA Astrophysics Data System (ADS)

    Matters, David; McClory, John; Carroll, James; Chiara, Chris; Fotiades, Nikolaos; Devlin, Matt; Nelson, Ron O.

    2015-04-01

    Evaluated nuclear structure data for 186 Re identifies the majority of spin-parity assignments as tentative, with approximate values associated with the energies of several levels and transitions. In particular, the absence of known transitions that feed the Jπ =8+ isomer motivates their discovery, which would have astrophysical implications and a potential application in the development of an isomer power source. Using the GErmanium Array for Neutron Induced Excitations (GEANIE) spectrometer at the Los Alamos Neutron Science Center (LANSCE) Weapons Neutron Research (WNR) facility, the (n,2n γ) and (n,n' γ) reactions in a 99.52% enriched 187 Re target were used to measure γ-ray excitation functions in 186 Re and 187 Re, respectively. A preliminary analysis of the data obtained from the experiment reveals several new transitions in 186 Re and 187 Re.

  16. Use of Web 2.0 Social Media Platforms to Promote Community-Engaged Research Dialogs: A Preliminary Program Evaluation

    PubMed Central

    Valdez Soto, Miguel; Bishop, Shawn G; Aase, Lee A; Timimi, Farris K; Montori, Victor M; Patten, Christi A

    2016-01-01

    Background Community-engaged research is defined by the Institute of Medicine as the process of working collaboratively with groups of people affiliated by geographic proximity, special interests, or similar situations with respect to issues affecting their well-being. Traditional face-to-face community-engaged research is limited by geographic location, limited in resources, and/or uses one-way communications. Web 2.0 technologies including social media are novel communication channels for community-engaged research because these tools can reach a broader audience while promoting bidirectional dialogs. Objective This paper reports on a preliminary program evaluation of the use of social media platforms for promoting engagement of researchers and community representatives in dialogs about community-engaged research. Methods For this pilot program evaluation, the Clinical and Translational Science Office for Community Engagement in Research partnered with the Social Media Network at our institution to create a WordPress blog and Twitter account. Both social media platforms were facilitated by a social media manager. We used descriptive analytics for measuring engagement with WordPress and Twitter over an 18-month implementation period during 2014-2016. For the blog, we examined type of user (researcher, community representative, other) and used content analysis to generate the major themes from blog postings. For use of Twitter, we examined selected demographics and impressions among followers. Results There were 76 blog postings observed from researchers (48/76, 64%), community representatives (23/76, 32%) and funders (5/76, 8%). The predominant themes of the blog content were research awareness and dissemination of community-engaged research (35/76, 46%) and best practices (23/76, 30%). For Twitter, we obtained 411 followers at the end of the 18-month evaluation period, with an increase of 42% (from 280 to 411) over the final 6 months. Followers reported varied

  17. Preliminary evaluation of daylily cultivars for rust resistance in a landscaping setting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A large, established landscape collection of 575 newer cultivars was evaluated for daylily rust which had not been sprayed with fungicides to prevent infection during 2013. The warm, damp summer of 2013 was ideal for spread of daylily rust. A total of 119 of the 575 cultivars received a median ratin...

  18. Preliminary Evaluation of Office of Academic Achievement's Programs 1990-1991. Report No. 91-4.

    ERIC Educational Resources Information Center

    Swanson, Judy

    Three programs sponsored by the Seattle (Washington) public schools' Office of Academic Achievement were evaluated: the Academic Achievement Project, Early Childhood Model (ECM) Schools, and Pilot Projects. Academic Achievement projects were designed to increase the academic achievement of at-risk learners and to decrease disproportionality. The…

  19. Preliminary evaluation of AERMOD using site specific stack and ambient sampling data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A cotton ginning industry-supported project was initiated in 2008 to develop a robust particulate matter (PM) dispersion modeling dataset that could be used for evaluating current and future PM dispersion models. This paper compares total PM data collected by the industry-supported study at one gin ...

  20. Preliminary evaluation of the Accident Response Mobile Manipulation System for accident site salvage operations

    SciTech Connect

    Trujillo, J.M.; Morse, W.D.; Jones, D.P.

    1994-10-01

    This paper describes and evaluates operational experiences with the Accident Response Mobile Manipulation System (ARMMS) during simulated accident site salvage operations which might involve nuclear weapons. The ARMMS is based upon a teleoperated mobility platform with two Schilling Titan 7F Manipulators.