Science.gov

Sample records for energy activation cross

  1. Transitions, cross sections and neutron binding energy in 186Re by Prompt Gamma Activation Analysis

    NASA Astrophysics Data System (ADS)

    Lerch, A. G.; Hurst, A. M.; Firestone, R. B.; Revay, Zs.; Szentmiklosi, L.; McHale, S. R.; McClory, J. W.; Detwiler, B.; Carroll, J. J.

    2014-03-01

    The nuclide 186Re possesses an isomer with 200,000 year half-life while its ground state has a half-life of 3.718 days. It is also odd-odd and well-deformed nucleus, so should exhibit a variety of other interesting nuclear-structure phenomena. However, the available nuclear data is rather sparse; for example, the energy of the isomer is only known to within + 7 keV and, with the exception of the J?=1- ground state, every proposed level is tentative in the ENSDF. Previously, Prompt Gamma Activation Analysis (PGAA) was utilized to study natRe with 186,188Re being produced via thermal neutron capture. Recently, an enriched 185Re target was irradiated by thermal neutrons at the Budapest Research Reactor to build on those results. Prompt (primary and secondary) and delayed gamma-ray transitions were measured with a large-volume, Compton-suppressed HPGe detector. Absolute cross sections for each gamma transition were deduced and corrected for self attenuation within the sample. Fifty-two primary gamma-ray transitions were newly identified and used to determine a revised value of the neutron binding energy. DICEBOX was used to simulate the decay scheme and the total radiative thermal neutron capture cross section was found to be 97+/-3 b Supported by DTRA (Detwiler) through HDTRA1-08-1-0014.

  2. Validation and divergence of the activation energy barrier crossing transition at the AOT/lecithin reverse micellar interface.

    PubMed

    Narayanan, S Shankara; Sinha, Sudarson Sekhar; Sarkar, Rupa; Pal, Samir Kumar

    2008-03-13

    In this report, the validity and divergence of the activation energy barrier crossing model for the bound to free type water transition at the interface of the AOT/lecithin mixed reverse micelle (RM) has been investigated for the first time in a wide range of temperatures by time-resolved solvation of fluorophores. Here, picosecond-resolved solvation dynamics of two fluorescent probes, ANS (1-anilino-8-naphthalenesulfonic acid, ammonium salt) and Coumarin 500 (C-500), in the mixed RM have been carefully examined at 293, 313, 328, and 343 K. Using the dynamic light scattering (DLS) technique, the size of the mixed RMs at different temperatures was found to have an insignificant change. The solvation process at the reverse micellar interface has been found to be the activation energy barrier crossing type, in which interface-bound type water molecules get converted into free type water molecules. The activation energies, Ea, calculated for ANS and C-500 are 7.4 and 3.9 kcal mol(-1), respectively, which are in good agreement with that obtained by molecular dynamics simulation studies. However, deviation from the regular Arrhenius type behavior was observed for ANS around 343 K, which has been attributed to the spatial heterogeneity of the probe environments. Time-resolved fluorescence anisotropy decay of the probes has indicated the existence of the dyes in a range of locations in RM. With the increase in temperature, the overall anisotropy decay becomes faster revealing the lability of the microenvironment at elevated temperatures. PMID:18281975

  3. Activation cross sections of deuteron induced reactions on niobium in the 30-50 MeV energy range

    NASA Astrophysics Data System (ADS)

    Ditrói, F.; Tárkányi, F.; Takács, S.; Hermanne, A.; Ignatyuk, A. V.

    2016-04-01

    Activation cross-sections of deuterons induced reactions on Nb targets were determined with the aim of different applications and comparison with theoretical models. We present the experimental excitation functions of 93Nb(d,x)93m,90Mo, 92m,91m,90Nb, 89,88Zr and 88,87m,87gY in the energy range of 30-50 MeV. The results were compared with earlier measurements and with the cross-sections calculated by means of the theoretical model codes ALICE-D, EMPIRE-D and TALYS (on-line TENDL-2014 and TENDL-2015 libraries). Possible applications of the radioisotopes are discussed in detail.

  4. Activation cross-sections of proton induced reactions on vanadium in the 37-65 MeV energy range

    NASA Astrophysics Data System (ADS)

    Ditrói, F.; Tárkányi, F.; Takács, S.; Hermanne, A.

    2016-08-01

    Experimental excitation functions for proton induced reactions on natural vanadium in the 37-65 MeV energy range were measured with the activation method using a stacked foil irradiation technique. By using high resolution gamma spectrometry cross-section data for the production of 51,48Cr, 48V, 48,47,46,44m,44g,43Sc and 43,42K were determined. Comparisons with the earlier published data are presented and results predicted by different theoretical codes (EMPIRE and TALYS) are included. Thick target yields were calculated from a fit to our experimental excitation curves and compared with the earlier experimental yield data. Depth distribution curves to be used for thin layer activation (TLA) are also presented.

  5. Measurement of activation cross-sections for high-energy neutron-induced reactions of Bi and Pb

    NASA Astrophysics Data System (ADS)

    Zaman, Muhammad; Kim, Guinyun; Kim, Kwangsoo; Naik, Haladhara; Shahid, Muhammad; Lee, Manwoo

    2015-08-01

    The cross-sections for 209Bi(n, 4n)206Bi, 209Bi(n, 5n)205Bi, natPb(n, xn)204mPb, natPb(n, xn)203Pb, natPb(n, xn)202mPb,natPb(n, xn)201Pb, natPb(n, xn)200Pb, natPb(n, αxn)203Hg and natPb(n, p xn)202Tl reactions were determined at the Korean Institute of Radiological and Medical Sciences (KIRAMS), Korea in the neutron energy range of 15.2 to 37.2 MeV. The above cross-sections were obtained by using the activation and off-line γ-ray spectrometric technique. The quasi-monoenergetic neutron used for the above reactions are based on the 9Be(p, n) reaction. Simulations of the spectral flux from the Be target were done using the MCNPX program. The cross-sections were estimated with the TALYS 1.6 code using the default parameter. The data from the present work and literature were compared with the data from the EAF-2010 and the TENDL-2013 libraries, and calculated values of TALYS 1.6 code. It shows that appropriate level density model, the γ-ray strength function, and the spin cut-off parameter are needed to obtain a good agreement between experimental data and theoretical values from TALYS 1.6 code.

  6. Activation energy and capture cross section of majority carrier traps in Zn doped InP

    NASA Technical Reports Server (NTRS)

    Rybicki, George; Williams, Wendell

    1993-01-01

    Schottky barrier diodes were fabricated on Zn doped InP Wafers. The diodes were radiation damaged with 2 MeV protons to a dose of 2 x 10(exp 12)cm(sup -2). The damage was analyzed by DLTS (deep level transient spectroscopy) using the double correlation technique. Capture cross sections were measured directly. Two major defects were observed in the DLTS spectra. The first defect, was H4 at Ev + 0.29 eV, with capture cross section 1.1 x 10(exp -17)cm(sup 2). The second defect, was H5 at Ev + 0.53 eV. Its capture cross section varied with temperature as described by the relationship sigma = sigma(sub 0) exp(delta(E)/kT) where sigma(sub 0) = 1.3 x 10(exp -19)cm(sup 2) and delta(E) = .08 eV. This relationship yields a sigma of 5.9 x 10(exp -21)cm(sup 2) at room temperature. The surprisingly small capture cross section of H5 and its temperature dependence are discussed in terms of the multiphonon emission process for carrier capture at the defect. The advantages of the improved experimental techniques used are also discussed.

  7. ACTIV87: Fast Neutron Activation Cross Section File

    Energy Science and Technology Software Center (ESTSC)

    1993-08-01

    4. HISTORICAL BACKGROUND AND INFORMATION ACTIV87 is a compilation of fast neutron induced activation reaction cross-sections. The compilation covers energies from threshold to 20 MeV and is based on evaluated data taken from other evaluated data libraries and individual evaluations. The majority of these evaluations were performed by using available experimental data. The aforementioned available experimental data were used in the selection of needed parameters for theoretical computations and for normalizing the results of suchmore » computations. Theoretical calculations were also used for interpolation and extrapolation of experimental cross-section data. All of the evaluated data curves were compared with experimental data that had been reported over the four year period preceding 1987. Only those cross-sections not in contradiction with experimental data that was current in 1987 were retained in the activation file, ACTIV87. In cases of several conflicting evaluations, that evaluation was chosen which best corresponded to the experimental data. A few evaluated curves were renormalized in accordance with the results of the latest precision measurements. 5. APPLICATION OF THE DATA 6. SOURCE AND SCOPE OF DATA The following libraries and individual files of evaluated neutron cross-section data were used for the selection of the activation cross-sections: the BOSPOR Library, the Activation File of the Evaluated Nuclear Data Library, the Evaluated Neutron Data File (ENDF/B-V) Activation File, the International Reactor Dosimetry File (IRDF-82), and individual evaluations carried out under various IAEA research contracts. The file of selected reactions contains 206 evaluated cross-section curves of the (n,2n), (n,p) and (n,a) reactions which lead to radioactive products and may be used in many practical applications of neutron activation analysis. Some competing activation reactions, usually with low cross-section values, are given for completeness.« less

  8. Extension of the energy range of experimental activation cross-sections data of deuteron induced nuclear reactions on indium up to 50MeV.

    PubMed

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2015-11-01

    The energy range of our earlier measured activation cross-sections data of longer-lived products of deuteron induced nuclear reactions on indium were extended from 40MeV up to 50MeV. The traditional stacked foil irradiation technique and non-destructive gamma spectrometry were used. No experimental data were found in literature for this higher energy range. Experimental cross-sections for the formation of the radionuclides (113,110)Sn, (116m,115m,114m,113m,111,110g,109)In and (115)Cd are reported in the 37-50MeV energy range, for production of (110)Sn and (110g,109)In these are the first measurements ever. The experimental data were compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS 1.6 nuclear model code as listed in the on-line library TENDL-2014. PMID:26226220

  9. A Modified activation method for reaction total cross section and yield measurements at low astrophysically relevant energies

    NASA Astrophysics Data System (ADS)

    Artemov, S. V.; Igamov, S. B.; Karakhodjaev, A. A.; Radyuk, G. A.; Tojiboyev, O. R.; Salikhbaev, U. S.; Ergashev, F. Kh.; Nam, I. V.; Aliev, M. K.; Kholbaev, I.; Rumi, R. F.; Khalikov, R. I.; Eshkobilov, Sh. Kh.; Muminov, T. M.

    2016-07-01

    The activation method is proposed for collection of the sufficient statistics during the investigation of the nuclear astrophysical reactions at low energies with the short-living residual nuclei formation. The main feature is a multiple cyclical irradiation of a target by an ion beam and measurement of the radioactivity decay curve. The method was tested by the yield measurement of the 12C(p,γ)13N reaction with detecting the annihilation γγ- coincidences from 13N(β+ν)13C decay at the two-arm scintillation spectrometer.

  10. Cross Cultural Watershed Partners. Activities Manual.

    ERIC Educational Resources Information Center

    Stapp, William B.; And Others

    The Global Rivers Environmental Education Network (GREEN) has developed this manual of background information and activities for teachers and students who are interested in adding a cross cultural component to their watershed education program, or who wish to include an environmental context to their cross cultural experience. The instructional…

  11. Activation cross-sections of proton induced nuclear reactions on thulium in the 20-45 MeV energy range.

    PubMed

    Tárkányi, F; Hermanne, A; Takács, S; Ditrói, F; Spahn, I; Ignatyuk, A V

    2012-01-01

    Cross-sections of proton induced nuclear reactions on (169)Tm were measured in the 20-45MeV energy range using the standard stacked-foil irradiation technique and high resolution gamma-ray spectroscopy. Experimental cross-sections and derived integral yields are reported for the production of (169,167,166)Yb and (168,167,166)Tm radioisotopes. The experimental data are analysed and compared to results of the earlier measurements and the theoretical model codes ALICE-IPPE, EMPIRE and TALYS. Application of the new cross-sections to the production of the (167)Tm medical radioisotope is discussed. PMID:21920768

  12. Activation Energy

    NASA Technical Reports Server (NTRS)

    Gadeken, Owen

    2002-01-01

    Teaming is so common in today's project management environment that most of us assume it comes naturally. We further assume that when presented with meaningful and challenging work, project teams will naturally engage in productive activity to complete their tasks. This assumption is expressed in the simple (but false) equation: Team + Work = Teamwork. Although this equation appears simple and straightforward, it is far from true for most project organizations whose reality is a complex web of institutional norms based on individual achievement and rewards. This is illustrated by the very first successful team experience from my early Air Force career. As a young lieutenant, I was sent to Squadron Officer School, which was the first in the series of Air Force professional military education courses I was required to complete during my career. We were immediately formed into teams of twelve officers. Much of the course featured competition between these teams. As the most junior member of my team, I quickly observed the tremendous pressure to show individual leadership capability. At one point early in the course, almost everyone in our group was vying to become the team leader. This conflict was so intense that it caused us to fail miserably in our first outdoor team building exercise. We spent so much time fighting over leadership that we were unable to complete any of the events on the outdoor obstacle course. This complete lack of success was so disheartening to me that I gave our team little hope for future success. What followed was a very intense period of bickering, conflict, and even shouting matches as our dysfunctional team tried to cope with our early failures and find some way to succeed. British physician and researcher Wilfred Bion (Experiences in Groups, 1961) discovered that there are powerful psychological forces inherent in all groups that divert from accomplishing their primary tasks. To overcome these restraining forces and use the potential

  13. Energy differential cross sections for F9+-impact single and double ionization of He

    NASA Astrophysics Data System (ADS)

    Pindzola, M. S.; Lee, T. G.; Colgan, J.

    2015-07-01

    Time-dependent close-coupling methods are used to calculate energy differential cross sections for the single and double ionization of He by impact with F9+ ions at 4.0 MeV amu-1. Single ionization energy differential cross sections using both a one active electron method and a two active electron method are compared with recent experimental results. Double ionization energy differential cross sections using a two active electron method are presented to guide future experiments.

  14. Extension of the energy range of the experimental activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium up to 65MeV.

    PubMed

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2015-04-01

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides (159)Dy, (157)Dy, (155)Dy, (161)Tb, (160)Tb, (156)Tb, (155)Tb, (154m2)Tb, (154m1)Tb, (154g)Tb, (153)Tb, (152)Tb and (151)Tb are reported in the 36-65MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013. PMID:25644082

  15. Energy: A Cross-Curricular Approach.

    ERIC Educational Resources Information Center

    Lalonde, Christine

    This guide is based on the premise that lives (and lifestyles) revolve around the production, consumption, and conversion of energy. Yet for such an all-encompassing concept little accompanying factual knowledge exists at the grade-school level. The objectives (and the resulting activities and extensions) are focused on the needs of the upper…

  16. Energy assessment: physical activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physical activity is an important component of total energy expenditure, contributing to energy intake needs; it also provides certain health benefits. This review chapter provides state-of-the-art information to researchers and clinicians who are interested in developing research studies or interv...

  17. Measurements of the cross section for the (182)W(n,p)(182(m+g))Ta and (184)(n,p)(184)Ta reactions in the 14MeV energy range using the activation technique.

    PubMed

    Song, Yueli; Zhou, Fengqun; Tian, Mingli; Li, Yong; Yuan, Shuqing; Lan, Changlin

    2015-04-01

    The cross section for the (182)W(n,p)(182(m+g))Ta and (184)W(n,p)(184)Ta reactions has been measured in the neutron energy range of 13.5-14.7MeV using the activation technique and a coaxial HPGe γ-ray detector. In our experiment, the fast neutrons were produced by the T(d,n)(4)He reaction at the ZF-300-II Intense Neutron Generator at Lanzhou University. Natural wolfram foils of 99.9% purity were used as target materials. The neutron flux was determined using the monitor reaction (93)Nb(n,2n)(92m)Nb and the neutron energies were determined using the method of cross-section ratio measurements employing the (90)Zr(n,2n)(89)Zr to (93)Nb(n,2n)(92m)Nb reactions. The results of this work are compared with experimental data found in the literature and the estimates obtained from a published empirical formula based on the statistical model with Q-value dependence and odd-even effects taken into consideration. PMID:25617709

  18. Science Activities in Energy: Chemical Energy.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Presented is a science activities in energy package which includes 15 activities relating to chemical energy. Activities are simple, concrete experiments for fourth, fifth and sixth grades which illustrate principles and problems relating to energy. Each activity is outlined on a single card which is introduced by a question. A teacher's…

  19. Science Activities in Energy: Electrical Energy.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Presented is a science activities in energy package which includes 16 activities relating to electrical energy. Activities are simple, concrete experiments for fourth, fifth and sixth grades which illustrate principles and problems relating to energy. Each activity is outlined in a single card which is introduced by a question. A teacher's…

  20. Science Activities in Energy: Solar Energy.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Presented is a science activities in energy package which includes 12 activities relating to solar energy. Activities are simple, concrete experiments for fourth, fifth, and sixth grades, which illustrate principles and problems relating to energy. Each activity is outlined on a single card which is introduced by a question. A teacher's supplement…

  1. Changing Conceptions of Activation Energy.

    ERIC Educational Resources Information Center

    Pacey, Philip D.

    1981-01-01

    Provides background material which relates to the concept of activation energy, fundamental in the study of chemical kinetics. Compares the related concepts of the Arrhenius activation energy, the activation energy at absolute zero, the enthalpy of activation, and the threshold energy. (CS)

  2. Measurements of the neutron activation cross sections for Bi and Co at 386 MeV.

    PubMed

    Yashima, H; Sekimoto, S; Ninomiya, K; Kasamatsu, Y; Shima, T; Takahashi, N; Shinohara, A; Matsumura, H; Satoh, D; Iwamoto, Y; Hagiwara, M; Nishiizumi, K; Caffee, M W; Shibata, S

    2014-10-01

    Neutron activation cross sections for Bi and Co at 386 MeV were measured by activation method. A quasi-monoenergetic neutron beam was produced using the (7)Li(p,n) reaction. The energy spectrum of these neutrons has a high-energy peak (386 MeV) and a low-energy tail. Two neutron beams, 0° and 25° from the proton beam axis, were used for sample irradiation, enabling a correction for the contribution of the low-energy neutrons. The neutron-induced activation cross sections were estimated by subtracting the reaction rates of irradiated samples for 25° irradiation from those of 0° irradiation. The measured cross sections were compared with the findings of other studies, evaluated in relation to nuclear data files and the calculated data by Particle and Heavy Ion Transport code System code. PMID:24368868

  3. Mechanism of intersystem crossing of thermally activated delayed fluorescence molecules.

    PubMed

    Ogiwara, Toshinari; Wakikawa, Yusuke; Ikoma, Tadaaki

    2015-04-01

    The spin sublevel dynamics of the excited triplet state in thermally activated delayed fluorescence (TADF) molecules have not been investigated for high-intensity organic light-emitting diode materials. Understanding the mechanism for intersystem crossing (ISC) is thus important for designing novel TADF materials. We report the first study on the ISC dynamics of the lowest excited triplet state from the lowest excited singlet state with charge-transfer (CT) character of TADF molecules with different external quantum efficiencies (EQEs) using time-resolved electron paramagnetic resonance methods. Analysis of the observed spin polarization indicates a strong correlation of the EQE with the population rate due to ISC induced by hyperfine coupling with the magnetic nuclei. It is concluded that molecules with high EQE have an extremely small energy gap between the (1)CT and (3)CT states, which allows an additional ISC channel due to the hyperfine interactions. PMID:25774790

  4. The energy dependence of the total charm cross section

    SciTech Connect

    Vogt, R

    2007-10-18

    We discuss the energy dependence of the total charm cross section and some of its theoretical uncertainties including the quark mass, scale choice and the parton densities. We compare the next-to-leading order calculation of the total cross section with results obtained using PYTHIA.

  5. Non-Stationary Effects and Cross Correlations in Solar Activity

    NASA Astrophysics Data System (ADS)

    Nefedyev, Yuri; Panischev, Oleg; Demin, Sergey

    2016-07-01

    In this paper within the framework of the Flicker-Noise Spectroscopy (FNS) we consider the dynamic properties of the solar activity by analyzing the Zurich sunspot numbers. As is well-known astrophysics objects are the non-stationary open systems, whose evolution are the quite individual and have the alternation effects. The main difference of FNS compared to other related methods is the separation of the original signal reflecting the dynamics of solar activity into three frequency bands: system-specific "resonances" and their interferential contributions at lower frequencies, chaotic "random walk" ("irregularity-jump") components at larger frequencies, and chaotic "irregularity-spike" (inertial) components in the highest frequency range. Specific parameters corresponding to each of the bands are introduced and calculated. These irregularities as well as specific resonance frequencies are considered as the information carriers on every hierarchical level of the evolution of a complex natural system with intermittent behavior, consecutive alternation of rapid chaotic changes in the values of dynamic variables on small time intervals with small variations of the values on longer time intervals ("laminar" phases). The jump and spike irregularities are described by power spectra and difference moments (transient structural functions) of the second order. FNS allows revealing the most crucial points of the solar activity dynamics by means of "spikiness" factor. It is shown that this variable behaves as the predictor of crucial changes of the sunspot number dynamics, particularly when the number comes up to maximum value. The change of averaging interval allows revealing the non-stationary effects depending by 11-year cycle and by inside processes in a cycle. To consider the cross correlations between the different variables of solar activity we use the Zurich sunspot numbers and the sequence of corona's radiation energy. The FNS-approach allows extracting the

  6. Activities Handbook for Energy Education.

    ERIC Educational Resources Information Center

    DeVito, Alfred; Krockover, Gerald H.

    The purpose of this handbook is to present information about energy and to translate this information into learning activities for children. Chapter 1, "Energy: A Delicate Dilemma," presents activities intended to provide an introduction to energy and energy usage. Chapter 2, "What are the Sources of Energy?" provides background information and…

  7. Energy Adventure Center. Activity Book.

    ERIC Educational Resources Information Center

    Carlton, Linda L.

    Energy activities are provided in this student activity book. They include: (1) an energy walk; (2) forms of energy in the home; (3) energy conversion; (4) constructing a solar hot dog cooker (with instructions for drawing a parabola); (5) interviewing senior citizens to learn about energy use in the past; (6) packaging materials; (7) insulation;…

  8. Science Activities in Energy: Conservation.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Presented is a science activities in energy package which includes 14 activities relating to energy conservation. Activities are simple, concrete experiments for fourth, fifth and sixth grades, which illustrate principles and problems relating to energy. Each activity is outlined on a simple card which is introduced by a question. A teacher's…

  9. Cross-impacts analysis development and energy policy analysis applications

    SciTech Connect

    Roop, J.M.; Scheer, R.M.; Stacey, G.S.

    1986-12-01

    Purpose of this report is to describe the cross-impact analysis process and microcomputer software developed for the Office of Policy, Planning, and Analysis (PPA) of DOE. First introduced in 1968, cross-impact analysis is a technique that produces scenarios of future conditions and possibilities. Cross-impact analysis has several unique attributes that make it a tool worth examining, especially in the current climate when the outlook for the economy and several of the key energy markets is uncertain. Cross-impact analysis complements the econometric, engineering, systems dynamics, or trend approaches already in use at DOE. Cross-impact analysis produces self-consistent scenarios in the broadest sense and can include interaction between the economy, technology, society and the environment. Energy policy analyses that couple broad scenarios of the future with detailed forecasting can produce more powerful results than scenario analysis or forecasts can produce alone.

  10. Fission cross sections in the intermediate energy region

    SciTech Connect

    Lisowski, P.W.; Gavron, A.; Parker, W.E.; Ullmann, J.L.; Balestrini, S.J. ); Carlson, A.D.; Wasson, O.A. ); Hill, N.W. )

    1991-01-01

    Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission cross section data for {sup 235}U and {sup 238}U compared to intranuclear cascade and statistical model predictions.

  11. Classroom Activities for Cross-Cultural Learning.

    ERIC Educational Resources Information Center

    Zanger, Virginia Vogel, Ed.; And Others

    One-fourth of the students in Boston public schools have parents who were born outside of the United States. This guide contains a series of classroom activities, produced by Boston teachers and aides, that are designed to take advantage of the abundant cultural diversity found in Boston schools by encouraging these dual-culture students to share…

  12. High Energy Measurement of the Deuteron Photodisintegration Differential Cross Section

    SciTech Connect

    Elaine Schulte

    2002-05-01

    New measurements of the high energy deuteron photodisintegration differential cross section were made at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia. Two experiments were performed. Experiment E96-003 was performed in experimental Hall C. The measurements were designed to extend the highest energy differential cross section values to 5.5 GeV incident photon energy at forward angles. This builds upon previous high energy measurements in which scaling consistent with the pQCD constituent counting rules was observed at 90 degrees and 70 degrees in the center of mass. From the new measurements, a threshold for the onset of constituent counting rule scaling seems present at transverse momentum approximately 1.3 GeV/c. The second experiment, E99-008, was performed in experimental Hall A. The measurements were designed to explore the angular distribution of the differential cross section at constant energy. The measurements were made symmetric about 90 degrees

  13. Science Activities in Energy: Wind Energy.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Included in this science activities energy package are 12 activities related to wind energy for elementary students. Each activity is outlined on a single card and is introduced by a question. Topics include: (1) At what time of day is there enough wind to make electricity where you live?; (2) Where is the windiest spot on your schoolground?; and…

  14. Locating Minimum Energy Crossing Points Using Eom-Cc Methods

    NASA Astrophysics Data System (ADS)

    Epifanovsky, E.; Krylov, A. I.

    2009-06-01

    Non-adiabatic and spin-forbidden processes involve transitions between electronic states through potential energy surface (PES) crossings. They are often found in atmospheric and combustion chemistry, photochemistry and photobiology. To describe the kinetics of such processes, a version of transition state theory can be applied. Locating the minimum energy crossing point of the PESs is the first step of characterizing a spin-forbidden reaction. The point corresponds to the transition state of the process. This work presents a computational procedure for minimizing singlet-triplet crossings of PESs, which is applied to a benchmark series of methylene-related radicals, formaldehyde, and oxybenzene, an intermediate in atmospheric formation of phenol. The intersection minimum in the studied methylene-related radicals is located very close to the excited state minimum, singlet for CH_2 and triplet for CHF and CF_2. The crossing in oxybenzene is found along the CO wagging coordinate. In the case of para-benzyne, which has a singlet-triplet adiabatic excitation energy of less than 0.2 eV, the crossing minimum is unexpectedly located 0.65 eV above the ground state equilibrium energy and corresponds to a distorted ring geometry.

  15. Science Activities in Energy: Solar Energy II.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Included in this science activities energy package are 14 activities related to solar energy for secondary students. Each activity is outlined on a single card and is introduced by a question such as: (1) how much solar heat comes from the sun? or (2) how many times do you have to run water through a flat-plate collector to get a 10 degree rise in…

  16. pi+- p differential cross sections at low energies

    SciTech Connect

    H. Denz; P. Amaudruz; J.T. Brack; J. Breitschopf; P. Camerini; J.L. Clark; H. Clement; L. Felawka; E. Fragiacomo; E.F. Gibson; N. Grion; G.J. Hofman; B. Jamieson; E.L. Mathie; R. Meier; G. Moloney; D. Ottewell; O. Patarakin; J.D. Patterson; M.M. Pavan; S. Piano; K. Raywood; R.A. Ristinen; R. Rui; M.E. Sevior; G.R. Smith; J. Stahov; R. Tacik; G.J. Wagner; F. von Wrochem; D.M. Yeomans

    2005-12-03

    Differential cross sections for pi- p and pi+ p elastic scattering were measured at five energies between 19.9 and 43.3 MeV. The use of the CHAOS magnetic spectrometer at TRIUMF, supplemented by a range telescope for muon background suppression, provided simultaneous coverage of a large part of the full angular range, thus allowing very precise relative cross section measurements. The absolute normalization was determined with a typical accuracy of 5 %. This was verified in a simultaneous measurement of muon proton elastic scattering. The measured cross sections show some deviations from phase shift analysis predictions, in particular at large angles and low energies. From the new data we determine the real part of the isospin forward scattering amplitude.

  17. Cross-Grade Comparison of Students' Understanding of Energy Concepts

    ERIC Educational Resources Information Center

    Saglam-Arslan, Aysegul

    2010-01-01

    The aims of this cross-grade study were (1) to determine the level of understanding of energy concepts of students at different academic grades and the differences in understanding between these grades and (2) to analyse the conceptual development of these students. Two hundred and forty-three students at 3 different levels (high school,…

  18. Fusion cross section of 12C+13C at sub-barrier energies

    NASA Astrophysics Data System (ADS)

    Zhang, N. T.; Tang, X. D.; Chen, H.; Chesneanu, D.; Straticiuc, M.; Trache, L.; Burducea, I.; Li, K. A.; Li, Y. J.; Ghita, D. G.; Margineanu, R.; Pantelica, A.; Gomoiu, C.

    2016-02-01

    In the recent work at Notre Dame, correlations between three carbon isotope fusion systems have been studied and it is found that the fusion cross sections of 12C+13Cand 13C+13C provide an upper limit on the fusion cross section of the astrophysically important 12C+12C reaction.The aim of this work is to continue such research by measuring the fusion cross section of the 12C+13C reaction to lower energies. In this experiment, the off-line activity measurement was performed in the ultra-low background laboratory 12C+13C and the fusion cross section for has been determined in the energy range of Ec.m. =2.5-6.8 MeV. Comparison between this work and several models is also presented.

  19. Activities for Teaching Solar Energy.

    ERIC Educational Resources Information Center

    Mason, Jack Lee; Cantrell, Joseph S.

    1980-01-01

    Plans and activities are suggested for teaching elementary children about solar energy. Directions are included for constructing a flat plate collector and a solar oven. Activities for a solar field day are given. (SA)

  20. Energy transfer between laser beams crossing in ignition hohlraums

    SciTech Connect

    Michel, P; Divol, L; Williams, E A; Thomas, C A; Callahan, D A; Weber, S; Haan, S W; Salmonson, J D; Dixit, S; Hinkel, D E; Edwards, M J; MacGowan, B J; Lindl, J D; Glenzer, S H; Suter, L J

    2008-10-03

    The full scale modeling of power transfer between laser beams crossing in plasmas is presented. A new model was developed, allowing calculation of the propagation and coupling of pairs of laser beams with their associated plasma wave in three dimensions. The full laser beam smoothing techniques used in ignition experiments are modeled, and their effects on crossed-beam energy transfer is investigated. A shift in wavelength between the beams can move the instability off resonance and reduce the transfer, hence preserving the symmetry of the capsule implosion.

  1. Improved activation cross sections for vanadium and titanium

    SciTech Connect

    Muir, D.W.; Arthur, E.D.

    1983-01-01

    Vanadium alloys such as V-20Ti and V-Cr-Ti are attractive candidates for use as structural materials in fusion-reactor blankets. The virtual absence of long-lived activation products in these alloys suggest the possibility of reprocessing on an intermediate time scale. We have employed the modern Hauser-Feshbach nuclear-model code GNASH to calculate cross sections for neutron-activation reactions in /sup 50/V and /sup 51/V, to allow a more accurate assessment of induced radioactivity in vanadium alloys. In addition, cross sections are calculated for the reactions /sup 46/Ti(n,2n) and /sup 45/Ti(n,2n) in order to estimate the production of /sup 44/Ti, a 1.2-MeV gamma-ray source with a half-life of 47 years.

  2. Activation cross sections of proton induced nuclear reactions on palladium up to 80MeV.

    PubMed

    Tárkányi, F; Ditrói, F; Takács, S; Csikai, J; Hermanne, A; Uddin, M S; Baba, M

    2016-08-01

    Activation cross sections of proton induced nuclear reactions on palladium were measured up to 80MeV by using the stacked foil irradiation technique and gamma ray spectrometry. The beam intensity, the incident energy and the energy degradation were controlled by a method based on flux constancy via normalization to the excitation functions of monitor reactions measured in parallel. Excitation functions for direct and cumulative cross-sections were measured for the production of (104m,104g,105g,106m,110m)Ag, (100,101)Pd, (99m,99g,100,101m,101g,102m,102g,105)Rh and (103,97)Ru radioisotopes. The cross section data were compared with the theoretical predictions of TENDL-2014 and -2015 libraries. For practical applications thick target yields were derived from the measured excitation functions. Application in the field of medical radionuclide production is shortly discussed. PMID:27235887

  3. Energy Dependent DVCS Cross Sections from JLab Hall A

    NASA Astrophysics Data System (ADS)

    Hyde, Charles; JLab Hall A Collaboration

    2013-10-01

    In 2010, in experiments E07-007 (hydrogen target) and E08-025 (deuterium target), the Jefferson Lab Hall A collaboration measured the helicity-dependent and helicity-independent cross sections at fixed xB = 0 . 36 , at Q2 = 1 . 5 , 1 . 75 , and 2 . 0 GeV2, and at two beam energies, 4.45 and 5.55 GeV. We detected the scattered electron in the Hall A High Resolution Spectrometer (HRS-L), and the coincidence photon in an upgraded 208 element PbF2 calorimeter. Exclusivity is inferred by missing mass in the (e ,e' γ) X reaction. In the unpolarized cross sections, the | DVCS | 2 and ℜe [DVCS† BH ] terms have different kinematic dependencies on the incident beam energy. I present preliminary results on the energy-dependence of the cross sections, and discuss their sensitivity to the Generalized Parton Distributions (GPDs). US DOE, NSF, and French IN2P3 and ANR.

  4. Cross-checking the symmetry energy at high densities

    NASA Astrophysics Data System (ADS)

    Yong, Gao-Chan

    2016-04-01

    By considering both the effects of the nucleon-nucleon short-range correlations and the isospin-dependent in-medium inelastic baryon-baryon scattering cross section in the transport model, two unrelated Au + Au experimental measurements at 400 MeV/nucleon beam energy are simultaneously analyzed, and a mildly soft symmetry energy (L (ρ0)=37 MeV) at supra-saturation densities is obtained. This result is compatible with recent result [Phys. Rev. C 92, 064304 (2015), 10.1103/PhysRevC.92.064304] shown by comparing the available data on the electric dipole polarizability with the theoretical predictions.

  5. Methods and procedures for evaluation of neutron-induced activation cross sections

    SciTech Connect

    Gardner, M.A.

    1981-09-01

    One cannot expect measurements alone to supply all of the neutron-induced activation cross-section data required by the fission reactor, fusion reactor, and nuclear weapons development communities, given the wide ranges of incident neutron energies, the great variety of possible reaction types leading to activation, and targets both stable and unstable. Therefore, the evaluator must look to nuclear model calculations and systematics to aid in fulfilling these cross-section data needs. This review presents some of the recent developments and improvements in the prediction of neutron activation cross sections, with specific emphasis on the use of empirical and semiempirical methods. Since such systematics require much less nuclear informaion as input and much less computational time than do the multistep Hauser-Feshbach codes, they can often provide certain cross-section data at a sufficient level of accuracy within a minimum amount of time. The cross-section information that these systematics can and cannot provide and those cases in which they can be used most reliably are discussed.

  6. Cross-domain active learning for video concept detection

    NASA Astrophysics Data System (ADS)

    Li, Huan; Li, Chao; Shi, Yuan; Xiong, Zhang; Hauptmann, Alexander G.

    2011-08-01

    As video data from a variety of different domains (e.g., news, documentaries, entertainment) have distinctive data distributions, cross-domain video concept detection becomes an important task, in which one can reuse the labeled data of one domain to benefit the learning task in another domain with insufficient labeled data. In this paper, we approach this problem by proposing a cross-domain active learning method which iteratively queries labels of the most informative samples in the target domain. Traditional active learning assumes that the training (source domain) and test data (target domain) are from the same distribution. However, it may fail when the two domains have different distributions because querying informative samples according to a base learner that initially learned from source domain may no longer be helpful for the target domain. In our paper, we use the Gaussian random field model as the base learner which has the advantage of exploring the distributions in both domains, and adopt uncertainty sampling as the query strategy. Additionally, we present an instance weighting trick to accelerate the adaptability of the base learner, and develop an efficient model updating method which can significantly speed up the active learning process. Experimental results on TRECVID collections highlight the effectiveness.

  7. Modeling crossed-beam energy transfer for inertial confinement fusion

    NASA Astrophysics Data System (ADS)

    Marion, D. J. Y.; Debayle, A.; Masson-Laborde, P.-E.; Loiseau, P.; Casanova, M.

    2016-05-01

    We developed a numerical code that describes both the energy transfer occurring when two or more laser beams overlap in a weakly non-homogeneous plasma, and the beam energy losses associated with the electron-ion collisions. The numerical solutions are validated with both the exact analytical solutions in homogeneous plasmas, and with new approximate analytical solutions in non-homogeneous plasmas that include the aforementioned inverse bremsstrahlung effect. Comparisons with kinetic particle-in-cell simulations are satisfactory, provided the acoustic wave-breaking limit and the self-focusing regime are not reached. An application of the Cross-Beam Energy Transfer model is shown for a typical case of indirect-drive implosion in a gold hohlraum.

  8. Strong optical activity from twisted-cross photonic metamaterials.

    PubMed

    Decker, M; Ruther, M; Kriegler, C E; Zhou, J; Soukoulis, C M; Linden, S; Wegener, M

    2009-08-15

    Following a recent theoretical suggestion and microwave experiments, we fabricate photonic metamaterials composed of pairs of twisted gold crosses using two successive electron-beam-lithography steps and intermediate planarization via a spin-on dielectric. The resulting two effective resonances of the coupled system lie in the 1-2 microm wavelength regime and exhibit pronounced circular dichroism, while the circular polarization conversion is very small. In between the two resonances, we find a fairly broad spectral regime with strong optical activity, i.e., with a pure rotation of incident linear polarization. The measured optical transmittance spectra agree well with theory. PMID:19684829

  9. Proton capture cross sections on neutron-magic 144Sm at astrophysically relevant energies

    NASA Astrophysics Data System (ADS)

    Kinoshita, N.; Hayashi, K.; Ueno, S.; Yatsu, Y.; Yokoyama, A.; Takahashi, N.

    2016-02-01

    Background: The p nuclei, which are not produced by neutron capture processes, are present with a typical isotopic abundance of 0.01%-0.3%. Abundance decreases with an increase in atomic number. However, the neutron-magic isotopes of 92Mo and 144Sm exhibit unusually large abundances in comparison. A combination of proton and α -particle capture reactions and neutron emission reactions are key to understanding this issue. Currently, complex network calculations do not have access to much experimental data, and hence require theoretically predicted reaction rates in order to estimate final abundances produced in nucleosynthesis. Purpose: Few experimental cross sections of (p ,γ) reactions on heavy nuclides with mass numbers of 130-150 have been reported. The 144Sm(p ,γ )145Eu reaction is the main destruction pathway for the nucleosynthesis of the 144Sm nuclide. In the present paper, experimental cross sections of the 144Sm(p ,γ )145Eu reaction at a range including astrophysically relevant energies for the p process were determined to compare with theoretical predictions using the Hauser-Feshback statistical model. Methods: The 144Sm was deposited on a high-purity Al foil with the molecular plating method. Stacks consisting of Ta degrader foils, 144Sm targets, and Cu foils used as flux monitors were irradiated with 14.0-MeV proton beams. The 144Sm(p ,γ )145Eu cross sections were determined from the 145Eu activities and the proton fluence estimated from the 65Zn activity in the Cu monitor foil. The proton energies bombarded on each 144Sm target were estimated using srim2013. Results: We determined the 144Sm(p ,γ )145Eu cross sections at proton energies between 2.8 and 7.6 MeV. These energies encompass nucleosynthesis temperatures between 3 and 5 GK. The cross sections at energies higher than 3.8 MeV agreed well with theoretically predicted cross sections using talys using the generalized superfluid (GS) model for level densities. However, calculations using non

  10. Partial cross sections of helium satellites at medium photon energies

    SciTech Connect

    Wehlitz, R.; Sellin, I.A.; Hemmers, O.

    1997-04-01

    Still of current interest is the important role of single ionization with excitation compared to single ionization alone. The coupling between the electrons and the incoming photon is a single-particle operator. Thus, an excitation in addition to an ionization, leading to a so-called satellite line in a photoelectron spectrum, is entirely due to electron-electron interaction and probes the electron correlation in the ground and final state. Therefore the authors have undertaken the study of the intensity of helium satellites He{sup +}nl (n = 2 - 6) relative to the main photoline (n = 1) as a function of photon energy at photon energies well above threshold up to 900 eV. From these results they could calculate the partial cross-sections of the helium satellites. In order to test the consistency of their satellite-to-1s ratios with published double-to-single photoionization ratios, the authors calculated the double-to-single photoionization ratio from their measured ratios using the theoretical energy-distribution curves of Chang and Poe and Le Rouzo and Dal Cappello which proved to be valid for photon energies below 120 eV. These calculated double-to-single ionization ratios agree fairly well with recent ion measurements. In the lower photon energy range the authors ratios agree better with the ratios of Doerner et al. while for higher photon energies the agreement is better with the values of Levin et al.

  11. Protein A-like activity and streptococcal cross-reactions.

    PubMed Central

    Kingston, D

    1981-01-01

    Recognition of the protein A-like activity of some strains of group A streptococci has thrown doubt on much previous work suggesting antigenic cross-reactions between these streptococci and mammalian tissues. The strains used in our previous studies have now been examined by the mixed reverse passive antiglobulin reaction (MRPAH) for the 'non-specific' absorption of purified Fc portion of human IgG. They were found to have only traces of activity. The strain of Staphylococcus aureus used to control 'non-specific' absorption by bacterial cell walls was strongly positive. Protein A-like material as detected in this way was not therefore responsible for our earlier results. PMID:7039880

  12. Crossed-beam energy transfer in direct-drive implosions

    SciTech Connect

    Seka, W; Edgell, D H; Michel, D T; Froula, D H; Goncharov, V N; Craxton, R S; Divol, L; Epstein, R; Follett, R; Kelly, J H; Kosc, T Z; Maximov, A V; McCrory, R L; Meyerhofer, D D; Michel, P; Myatt, J F; Sangster, T C; Shvydky, A; Skupsky, S; Stoeckl, C

    2012-05-22

    Direct-drive-implosion experiments on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have showed discrepancies between simulations of the scattered (non-absorbed) light levels and measured ones that indicate the presence of a mechanism that reduces laser coupling efficiency by 10%-20%. This appears to be due to crossed-beam energy transfer (CBET) that involves electromagnetic-seeded, low-gain stimulated Brillouin scattering. CBET scatters energy from the central portion of the incoming light beam to outgoing light, reducing the laser absorption and hydrodynamic efficiency of implosions. One-dimensional hydrodynamic simulations including CBET show good agreement with all observables in implosion experiments on OMEGA. Three strategies to mitigate CBET and improve laser coupling are considered: the use of narrow beams, multicolor lasers, and higher-Z ablators. Experiments on OMEGA using narrow beams have demonstrated improvements in implosion performance.

  13. Solar Energy Project, Activities: Biology.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of biology experiments. Each unit presents an introduction; objectives; skills and knowledge needed; materials; methods; questions; recommendations for further work; and a teacher information sheet. The teacher information…

  14. Activation energy measurements of cheese

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperature sweeps of cheeses using small amplitude oscillatory shear tests produced values for activation energy of flow (Ea) between 30 and 44 deg C. Soft goat cheese and Queso Fresco, which are high-moisture cheeses and do not flow when heated, exhibited Ea values between 30 and 60 kJ/mol. The ...

  15. Active calibration target for bistatic radar cross-section measurements

    NASA Astrophysics Data System (ADS)

    Pienaar, M.; Odendaal, J. W.; Joubert, J.; Cilliers, J. E.; Smit, J. C.

    2016-05-01

    Either passive calibration targets are expensive and complex to manufacture or their bistatic radar cross section (RCS) levels are significantly lower than the monostatic RCS levels of targets such as spheres, dihedral, and trihedral corner reflectors. In this paper the performance of an active calibration target with relative high bistatic RCS values is illustrated as a reference target for bistatic RCS measurements. The reference target is simple to manufacture, operates over a wide frequency range, and can be configured to calibrate all four polarizations (VV, HH, HV, and VH). Bistatic RCS measurements of canonical targets, performed in a controlled environment, are calibrated with the reference target and the results are compared to simulated results using FEKO.

  16. Activation Energies of Plasmonic Catalysts.

    PubMed

    Kim, Youngsoo; Dumett Torres, Daniel; Jain, Prashant K

    2016-05-11

    The activation energy of a catalytic reaction serves not only as a metric of the efficacy of a catalyst but also as a potential indicator of mechanistic differences between the catalytic and noncatalytic reaction. However, activation energies are quite underutilized in the field of photocatalysis. We characterize in detail the effect of visible light excitation on the activation enthalpy of an electron transfer reaction photocatalyzed by plasmonic Au nanoparticles. We find that in the presence of visible light photoexcitation, the activation enthalpy of the Au nanoparticle-catalyzed electron transfer reaction is significantly reduced. The reduction in the activation enthalpy depends on the excitation wavelength, the incident laser power, and the strength of a hole scavenger. On the basis of these results, we argue that the activation enthalpy reduction is directly related to the photoelectrochemical potential built-up on the Au nanoparticle under steady-state light excitation, analogous to electrochemical activation. Under optimum light excitation conditions, a potential as high as 240 mV is measured. The findings constitute more precise insights into the mechanistic role and energetic contribution of plasmonic excitation to chemical reactions catalyzed by transition metal nanoparticles. PMID:27064549

  17. H-N2 interaction energies, transport cross sections, and collision integrals

    NASA Technical Reports Server (NTRS)

    Stallcop, James R.; Partridge, Harry; Walch, Stephen P.; Levin, Eugene

    1992-01-01

    The energies for the interaction of a hydrogen atom with a nitrogen molecule have been calculated for large separation distances using a complete-active-space self-consistent-field/externally contracted configuration interaction method. H-N2 transport cross sections and collision integrals have been calculated using sudden approximations and a semiclassical description of the scattering. The values of these quantities are found to be close to the corresponding values determined from the average (isotropic) potential energy. The collision integrals are applied to determine diffusion and viscosity coefficients; the theoretical diffusion agrees well with the measured data available from experiments at low temperatures.

  18. Energy Technology: A Cross-Curricular Approach in Japan

    ERIC Educational Resources Information Center

    Yamazaki, Sadato; King, Cyril; Shinde, Mika; Ohiwa, Osamu; Hirai, Sohichiro

    2004-01-01

    This article briefly describes a curriculum study that had two main purposes. The first purpose was to develop and reflect upon a new energy technology curriculum at the lower secondary school level using an action research method. The second purpose was to determine the effect of collaborative activities, with the families of the pupils enrolled…

  19. Energy and angle differential cross sections for the electron-impact double ionization of helium

    SciTech Connect

    Colgan, James P; Pindzola, M S; Robicheaux, F

    2008-01-01

    Energy and angle differential cross sections for the electron-impact double ionization of helium are calculated using a non-perturbative time-dependent close-coupling method. Collision probabilities are found by projection of a time evolved nine dimensional coordinate space wave function onto fully antisymmetric products of spatial and spin functions representing three outgoing Coulomb waves. At an incident energy of 106 eV, we present double energy differential cross sections and pentuple energy and angle differential cross sections. The pentuple energy and angle differential cross sections are found to be in relative agreement with the shapes observed in recent (e,3e) reaction microscope experiments. Integration of the differential cross sections over all energies and angles yields a total ionization cross section that is also in reasonable agreement with absolute crossed-beams experiments.

  20. High energy activation data library (HEAD-2009)

    NASA Astrophysics Data System (ADS)

    Korovin, Yu. A.; Natalenko, A. A.; Stankovskiy, A. Yu.; Mashnik, S. G.; Konobeyev, A. Yu.

    2010-12-01

    A proton activation data library for 682 nuclides from 1H to 210Po in the energy range from 150 MeV up to 1 GeV was developed. To calculate proton activation data, the MCNPX 2.6.0 and CASCADE/INPE codes were chosen. Different intranuclear cascade, preequilibrium, and equilibrium nuclear reaction models and their combinations were used. The optimum calculation models have been chosen on the basis of statistical correlations for calculated and experimental proton data taken from the EXFOR library of experimental nuclear data. All the data are written in ENDF-6 format. The library is called HEPAD-2008 (High-Energy Proton Activation Data). A revision of IEAF-2005 neutron activation data library has been performed. A set of nuclides for which the cross-section data can be (and were) updated using more modern and improved models is specified, and the corresponding calculations have been made in the present work. The new version of the library is called IEAF-2009. The HEPAD-2008 and IEAF-2009 are merged to the final HEAD-2009 library.

  1. High energy activation data library (HEAD-2009)

    SciTech Connect

    Mashnik, Stepan G; Korovin, Yury A; Natalenko, Anatoly A; Konobeyev, Alexander Yu; Stankovskiy, A Yu

    2010-01-01

    A proton activation data library for 682 nuclides from 1 H to 210Po in the energy range from 150 MeV up to 1 GeV was developed. To calculate proton activation data, the MCNPX 2.6.0 and CASCADE/INPE codes were chosen. Different intranuclear cascade, preequilibrium, and equilibrium nuclear reaction models and their combinations were used. The optimum calculation models have been chosen on the basis of statistical correlations for calculated and experimental proton data taken from the EXFOR library of experimental nuclear data. All the data are written in ENDF-6 format. The library is called HEPAD-2008 (High-Energy Proton Activation Data). A revision of IEAF-2005 neutron activation data library has been performed. A set of nuclides for which the cross-section data can be (and were) updated using more modern and improved models is specified, and the corresponding calculations have been made in the present work. The new version of the library is called IEAF-2009. The HEPAD-2008 and IEAF-2009 are merged to the final HEAD-2009 library.

  2. Energy harvesting from vibration with cross-linked polypropylene piezoelectrets

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoqing; Wu, Liming; Sessler, Gerhard M.

    2015-07-01

    Piezoelectret films are prepared by modification of the microstructure of polypropylene foam sheets cross-linked by electronic irradiation (IXPP), followed by proper corona charging. Young's modulus, relative permittivity, and electromechanical coupling coefficient of the fabricated films, determined by dielectric resonance spectra, are about 0.7 MPa, 1.6, and 0.08, respectively. Dynamic piezoelectric d33 coefficients up to 650 pC/N at 200 Hz are achieved. The figure of merit (FOM, d33 ṡ g33) for a more typical d33 value of 400 pC/N is about 11.2 GPa-1. Vibration-based energy harvesting with one-layer and two-layer stacks of these films is investigated at various frequencies and load resistances. At an optimum load resistance of 9 MΩ and a resonance frequency of 800 Hz, a maximum output power of 120 μW, referred to the acceleration g due to gravity, is obtained for an energy harvester consisting of a one-layer IXPP film with an area of 3.14 cm2 and a seismic mass of 33.7 g. The output power can be further improved by using two-layer stacks of IXPP films in electric series. IXPP energy harvesters could be used to energize low-power electronic devices, such as wireless sensors and LED lights.

  3. Energy harvesting from vibration with cross-linked polypropylene piezoelectrets

    SciTech Connect

    Zhang, Xiaoqing; Wu, Liming; Sessler, Gerhard M.

    2015-07-15

    Piezoelectret films are prepared by modification of the microstructure of polypropylene foam sheets cross-linked by electronic irradiation (IXPP), followed by proper corona charging. Young’s modulus, relative permittivity, and electromechanical coupling coefficient of the fabricated films, determined by dielectric resonance spectra, are about 0.7 MPa, 1.6, and 0.08, respectively. Dynamic piezoelectric d{sub 33} coefficients up to 650 pC/N at 200 Hz are achieved. The figure of merit (FOM, d{sub 33} ⋅ g{sub 33}) for a more typical d{sub 33} value of 400 pC/N is about 11.2 GPa{sup −1}. Vibration-based energy harvesting with one-layer and two-layer stacks of these films is investigated at various frequencies and load resistances. At an optimum load resistance of 9 MΩ and a resonance frequency of 800 Hz, a maximum output power of 120 μW, referred to the acceleration g due to gravity, is obtained for an energy harvester consisting of a one-layer IXPP film with an area of 3.14 cm{sup 2} and a seismic mass of 33.7 g. The output power can be further improved by using two-layer stacks of IXPP films in electric series. IXPP energy harvesters could be used to energize low-power electronic devices, such as wireless sensors and LED lights.

  4. Measurements of fusion neutron yields by neutron activation technique: Uncertainty due to the uncertainty on activation cross-sections

    NASA Astrophysics Data System (ADS)

    Stankunas, Gediminas; Batistoni, Paola; Sjöstrand, Henrik; Conroy, Sean

    2015-07-01

    The neutron activation technique is routinely used in fusion experiments to measure the neutron yields. This paper investigates the uncertainty on these measurements as due to the uncertainties on dosimetry and activation reactions. For this purpose, activation cross-sections were taken from the International Reactor Dosimetry and Fusion File (IRDFF-v1.05) in 640 groups ENDF-6 format for several reactions of interest for both 2.5 and 14 MeV neutrons. Activation coefficients (reaction rates) have been calculated using the neutron flux spectra at JET vacuum vessel, both for DD and DT plasmas, calculated by MCNP in the required 640-energy group format. The related uncertainties for the JET neutron spectra are evaluated as well using the covariance data available in the library. These uncertainties are in general small, but not negligible when high accuracy is required in the determination of the fusion neutron yields.

  5. WAPA Daily Energy Accounting Activities

    Energy Science and Technology Software Center (ESTSC)

    1990-10-01

    ISA (Interchange, Scheduling, & Accounting) is the interchange scheduling system used by the DOE Western Area Power Administration to perform energy accounting functions associated with the daily activities of the Watertown Operations Office (WOO). The system's primary role is to provide accounting functions for scheduled energy which is exchanged with other power companies and power operating organizations. The system has a secondary role of providing a historical record of all scheduled interchange transactions. The followingmore » major functions are performed by ISA: scheduled energy accounting for received and delivered energy; generation scheduling accounting for both fossil and hydro-electric power plants; metered energy accounting for received and delivered totals; energy accounting for Direct Current (D.C.) Ties; regulation accounting; automatic generation control set calculations; accounting summaries for Basin, Heartland Consumers Power District, and the Missouri Basin Municipal Power Agency; calculation of estimated generation for the Laramie River Station plant; daily and monthly reports; and dual control areas.« less

  6. Prediction of energy expenditure and physical activity in preschoolers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate, nonintrusive, and feasible methods are needed to predict energy expenditure (EE) and physical activity (PA) levels in preschoolers. Herein, we validated cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on accelerometry and heart rate (HR) ...

  7. Correlates of college students' physical activity: cross-cultural differences.

    PubMed

    Seo, Dong-Chul; Torabi, Mohammad R; Jiang, Nan; Fernandez-Rojas, Xinia; Park, Bock-Hee

    2009-10-01

    This study examined cross-cultural differences in personal and behavioral determinants of vigorous-intensity and moderate-intensity physical activity (PA) among college students living in distinctly different cultures, that is, the United States, Costa Rica, India, and South Korea. Participants of this study were recruited from randomly chosen public universities in the 4 countries during the 2006-2007 academic year. A total of 4685 students participated in the study (response rate 90%). Vigorous-intensity PA was measured by asking on how many of the past 7 days the participants participated in PA for at least 20 minutes that made them sweat or breathe hard. For moderate-intensity PA, participants were asked on how many of the past 7 days they participated in PA for at least 30 minutes that did not make them sweat or breathe hard. Findings indicate that whereas perceived overweight and fruit and vegetable consumption are relatively culture-free predictors of PA, gender and TV/video watching are culture-specific predictors. Binge drinking was not predictive of meeting the vigorous-intensity and moderate-intensity PA guidelines in any of the 4 countries. PMID:19661101

  8. Investigation of activation cross-sections of alpha-induced nuclear reactions on natural cadmium

    NASA Astrophysics Data System (ADS)

    Khandaker, Mayeen Uddin; Kim, Kwangsoo; Lee, Manwoo; Kim, Guinyun

    2014-08-01

    We measured production cross-sections of Sn, In, and Cd radionuclides from alpha-induced reactions on natCd from their respective threshold to 45 MeV by using a stacked-foil activation technique at the MC-50 cyclotron of the Korea Institute of Radiological and Medical Sciences. The results were compared with the earlier measurements as well as with the theoretical values obtained from the TENDL-2012 library based on the TALYS 1.4 code. Our measurements for the 110,113g,117mSn, 108m,108g,109g,110m,110g,111g,113m,114m,115m,116m,117m,117gIn, and 111m,115gCd radionuclides in the energy region from the threshold energy to 45 MeV are in general good agreement with the other experimental data and calculated results. The integral yields for thick target were also deduced using the measured cross-sections and the stopping power of natural cadmium target and found in agreement with the directly measured yields available in the literature. The measured cross-sections find importance in various practical applications including nuclear medicine and improvement of nuclear model calculations.

  9. Low-Energy Electron Elastic Cross Sections for Lanthanide Atoms

    NASA Astrophysics Data System (ADS)

    Felfli, Z.; Msezane, A. Z.; Sokolovski, D.

    2009-05-01

    Dramatically sharp resonances characterize the near-threshold electron elastic scattering total cross sections for the lanthanide atoms, whose energy positions are identified with the binding energies (BEs) of the negative ions formed during the collisions as Regge resonances. The recently developed Regge-pole methodology which naturally embodies the crucial electron correlation effects together with a Thomas-Fermi type potential incorporating the vital core-polarization interaction are used for the calculations[1]. The extracted BEs of the lanthanide negative ions vary from 0.016 eV for Tm^- to 0.631 eV for Pr^-. All the negative ions of the lanthanides can be classified as weakly bound (BEs < 1.0 eV), while only three are tenuously bound (BEs < 0.1 eV) [2]. Ramsauer-Townsend minima, shape resonances and the Wigner threshold behavior for these lanthanides are also determined. Extracted EAs for La and the open d- and f- sub-shell Ce atoms agree excellently with the measured data [3, 4] while for Nd and Eu the agreement with calculated values [5] is outstanding. [1] D. Sokolovski et al, Phys. Rev. A76, 012705 (2007) [2] Z. Felfli et al, Phys. Rev. A 79, At Press (2009) [3] A. M. Covington et al, J. Phys. B 31, L855 (1998) [4] C.W. Walter et al, Phys. Rev. A 76, 052702 (2007) [5] S.M. O'Malley and D.R. Beck, Phys. Rev. A78, 012510 (2008) Supported by U.S. DOE, Division of Chemical Sciences.

  10. Energy Activities for the Primary Classroom. Revised.

    ERIC Educational Resources Information Center

    Tierney, Blue, Comp.

    An energy education program at the primary level should help students to understand the nature and importance of energy, consider different energy sources, learn about energy conservation, prepare for energy related careers, and become energy conscious in other career fields. The activities charts, readings, and experiments provided in this…

  11. Steering quantum transitions between three crossing energy levels

    SciTech Connect

    Ivanov, S. S.; Vitanov, N. V.

    2008-02-15

    We calculate the propagator and the transition probabilities for a coherently driven three-state quantum system. The energies of the three states change linearly in time, whereas the interactions between them are pulse shaped. We derive a highly accurate analytic approximation by assuming independent pairwise Landau-Zener transitions occurring instantly at the relevant avoided crossings, and adiabatic evolution elsewhere. Quantum interferences are identified, which occur due to different possible evolution paths in Hilbert space between an initial and a final state. A detailed comparison with numerical results for Gaussian-shaped pulses demonstrates a remarkable accuracy of the analytic approximation. We use the analytic results to derive estimates for the half-width of the excitation profile, and for the parameters required for creation of a maximally coherent superposition of the three states. These results are of potential interest in ladder climbing in alkali-metal atoms by chirped laser pulses, in quantum rotors, in transitions between Zeeman sublevels of a J=1 level in a magnetic field, and in control of entanglement of a pair of spin-1/2 particles. The results for the three-state system can be generalized, without essential difficulties, to higher dimensions.

  12. Neutron capture cross section of {sup 15}N at stellar energies

    SciTech Connect

    Meissner, J.; Schatz, H.; Herndl, H.; Wiescher, M.; Beer, H.; Kaeppeler, F.

    1996-02-01

    The neutron capture rate on {sup 15}N may be of considerable importance for {ital s}-process nucleosynthesis in red giants as well as for the nucleosynthesis in inhomogeneous big bang scenarios. We measured the reaction cross section of {sup 15}N({ital n},{gamma}){sup 16}N at the Forschungszentrum Karlsruhe with a fast cyclic neutron activation technique at laboratory neutron energies of 25, 152, and 370 keV. Direct capture and shell model calculations were performed to interpret the results. The presented reaction rate is 30{endash}50{percent} smaller than the previously used theoretical rates. {copyright} {ital 1996 The American Physical Society.}

  13. Comprehensive Cross-Training among STEM Disciplines in Geothermal Energy

    NASA Astrophysics Data System (ADS)

    Nunn, J. A.; Dutrow, B. L.

    2012-12-01

    One of the foremost areas of sustainability is society's need for energy. The US uses more energy per capita than any other country in the world with most of this energy coming from fossil fuels. With its link to climate change coupled with declining resources, renewable alternatives are being pursued. Given the high demand for energy, it is not a question of if these alternatives will be utilized but when and where. One of the "greenest" of the green technologies is geothermal energy. It is a renewable resource with a small environmental footprint. To educate advanced undergraduate and graduate students from across STEM disciplines in geothermal energy, a series of three distinct but linked and related courses are being developed and taught. Courses are focused on one of the STEM disciplines to provide students with essential discipline-specific knowledge and taught by different faculty members in the departments of geology, petroleum engineering and mathematics. These courses provide the foundation necessary for interdisciplinary research projects. The first course on Geologic Properties and Processes of Geothermal Energy was developed and taught in 2012. The class had an enrollment of 27 students including: 5 undergraduates and 4 graduate students in Geology, 12 undergraduates and two graduate students in Petroleum Engineering, and 4 non-matriculated undergraduate students. The course began with the essentials of heat and mass transfer, a common deficiency for all students, then progressed to the geologic materials of these systems: minerals, rocks and fluids. To provide students with first hand experience, two short research projects were embedded into the course. The first project involved analyses of cuttings from a well-studied geothermal system (Salton Sea, CA). Students were in teams consisting of both engineers and geologists. The first assignment was to identify minerals in the cuttings. They were then provided with XRD patterns for their cuttings to

  14. The cross-bridge spring: can cool muscles store elastic energy?

    PubMed

    George, N T; Irving, T C; Williams, C D; Daniel, T L

    2013-06-01

    Muscles not only generate force. They may act as springs, providing energy storage to drive locomotion. Although extensible myofilaments are implicated as sites of energy storage, we show that intramuscular temperature gradients may enable molecular motors (cross-bridges) to store elastic strain energy. By using time-resolved small-angle x-ray diffraction paired with in situ measurements of mechanical energy exchange in flight muscles of Manduca sexta, we produced high-speed movies of x-ray equatorial reflections, indicating cross-bridge association with myofilaments. A temperature gradient within the flight muscle leads to lower cross-bridge cycling in the cooler regions. Those cross-bridges could elastically return energy at the extrema of muscle lengthening and shortening, helping drive cyclic wing motions. These results suggest that cross-bridges can perform functions other than contraction, acting as molecular links for elastic energy storage. PMID:23618763

  15. Activated Brain Endothelial Cells Cross-Present Malaria Antigen

    PubMed Central

    Howland, Shanshan W.; Poh, Chek Meng; Rénia, Laurent

    2015-01-01

    In the murine model of cerebral malaria caused by P. berghei ANKA (PbA), parasite-specific CD8+ T cells directly induce pathology and have long been hypothesized to kill brain endothelial cells that have internalized PbA antigen. We previously reported that brain microvessel fragments from infected mice cross-present PbA epitopes, using reporter cells transduced with epitope-specific T cell receptors. Here, we confirm that endothelial cells are the population responsible for cross-presentation in vivo, not pericytes or microglia. PbA antigen cross-presentation by primary brain endothelial cells in vitro confers susceptibility to killing by CD8+ T cells from infected mice. IFNγ stimulation is required for brain endothelial cross-presentation in vivo and in vitro, which occurs by a proteasome- and TAP-dependent mechanism. Parasite strains that do not induce cerebral malaria were phagocytosed and cross-presented less efficiently than PbA in vitro. The main source of antigen appears to be free merozoites, which were avidly phagocytosed. A human brain endothelial cell line also phagocytosed P. falciparum merozoites. Besides being the first demonstration of cross-presentation by brain endothelial cells, our results suggest that interfering with merozoite phagocytosis or antigen processing may be effective strategies for cerebral malaria intervention. PMID:26046849

  16. Hadron cross sections at ultra high energies and unitarity bounds on diffraction dissociation

    NASA Technical Reports Server (NTRS)

    Yodh, G. B.; Gaisser, T. K.

    1985-01-01

    It was shown that if unitarity bounds on diffractive cross sections are valid at ultra high energies then diffractive dominance models which ascribe the increase in total hadron-hadron cross sections to diffractive processes only are ruled out. Calculations also show that cosmic ray cross sections derived from air shower experiments at ultra high energies clearly rule out models for hadron-hadron cross sections with nat.log ns energy dependence and favor those with nat.log n(2)s variation.

  17. Activation cross sections of proton induced nuclear reactions on gold up to 65MeV.

    PubMed

    Ditrói, F; Tárkányi, F; Takács, S; Hermanne, A

    2016-07-01

    Activation cross sections of proton induced reactions on gold for production of (197m,197g,195m,195g, 193m,193g,192)Hg, (196m,196g(cum),195g(cum),194,191(cum))Au, (191(cum))Pt and (192)Ir were measured up to 65MeV proton energy, some of them for the first time. The new data are in acceptably good agreement with the recently published earlier experimental data in the overlapping energy region. The experimental data are compared with the predictions of the TALYS 1.6 (results in TENDL-2015 on-line library) and EMPIRE 3.2 code. PMID:27156194

  18. Energy Storage. Teachers Guide. Science Activities in Energy.

    ERIC Educational Resources Information Center

    Jacobs, Mary Lynn, Ed.

    Included in this science activities energy package for students in grades 4-10 are 12 activities related to energy storage. Each activity is outlined on the front and back of a single sheet and is introduced by a key question. Most of the activities can be completed in the classroom with materials readily available in any community. Among the…

  19. Enhancement and suppresion of the neutrino-nucleon total cross section at ultra-high energies

    NASA Astrophysics Data System (ADS)

    Jalilian-Marian, Jamal

    2003-10-01

    We argue that high gluon density effects at small x are important for calculation of ultra-high energy neutrino nucleon cross sections due to the phenomenon of geometric scaling. We calculate the cross section for ν N arrow μ X, including high gluon density effects, using the all twist formalism of McLerran and Venugopalan and show that it can be related to the dipole nucleon cross section measured in DIS experiments. For neutrino energies of E_ν ˜ 10^12 GeV, the geometric scaling region extends all the way up to Q^2 ˜ M^2_W. We show that geometric scaling can lead to an enhancement of neutrino nucleon total cross section by 1-2 orders of magnitude compared to the leading twist cross section and discuss the implications for neutrino observatories. At extremely high energies, gluon saturation effects suppress the neutrino nucleon total cross section and lead to its unitarization.

  20. Enhancement and suppression of the neutrino-nucleon total cross section at ultrahigh energies

    NASA Astrophysics Data System (ADS)

    Jalilian-Marian, Jamal

    2003-09-01

    We argue that high gluon density effects at small x are important for the calculation of ultrahigh energy neutrino-nucleon cross sections due to the phenomenon of geometric scaling. We calculate the cross section for νN→μX, including high gluon density effects, using the all twist formalism of McLerran and Venugopalan and show that it can be related to the dipole nucleon cross section measured in deep inelastic scattering experiments. For neutrino energies of Eν˜1012 GeV, the geometric scaling region extends all the way up to Q2˜M2W. We show that geometric scaling can lead to an enhancement of the neutrino-nucleon total cross section by an order of magnitude compared to the leading twist cross section and discuss the implications for neutrino observatories. At extremely high energies, gluon saturation effects suppress the neutrino-nucleon total cross section and lead to its unitarization.

  1. Elastic and total cross sections for simple biomolecules in the intermediate energy range

    NASA Astrophysics Data System (ADS)

    Gupta, Dhanoj; Naghma, Rahla; Antony, Bobby

    2015-09-01

    The elastic and total cross sections for formaldehyde, acetaldehyde, acetone, 2-butanone and formamide are calculated using the spherical complex optical potential formalism in the intermediate energy range from 50 eV to 10 keV. These cross sections find application to various fields like radiation damage and biological sciences. The present results are compared with the available experimental and theoretical data and are found to give excellent agreement. The elastic cross sections reported for most of the targets in the present energy range are done for the first time. The energy dependence of the contribution of ionization and elastic cross section with respect to the total cross section and the correlation of total cross section with polarizability of the molecules are also studied.

  2. Elastic and total cross sections for simple biomolecules in the intermediate energy range

    SciTech Connect

    Gupta, Dhanoj; Naghma, Rahla; Antony, Bobby

    2015-09-15

    The elastic and total cross sections for formaldehyde, acetaldehyde, acetone, 2-butanone and formamide are calculated using the spherical complex optical potential formalism in the intermediate energy range from 50 eV to 10 keV. These cross sections find application to various fields like radiation damage and biological sciences. The present results are compared with the available experimental and theoretical data and are found to give excellent agreement. The elastic cross sections reported for most of the targets in the present energy range are done for the first time. The energy dependence of the contribution of ionization and elastic cross section with respect to the total cross section and the correlation of total cross section with polarizability of the molecules are also studied.

  3. Second Language Proficiency and Cross-Language Lexical Activation

    ERIC Educational Resources Information Center

    van Hell, Janet G.; Tanner, Darren

    2012-01-01

    Although research has consistently shown that a bilingual's two languages interact on multiple levels, it is also well-established that bilinguals can vary considerably in their proficiency in the second language (L2). In this paper we review empirical studies that have examined how differences in L2 proficiency modulate cross-language…

  4. Curve crossing for low-energy elastic scattering of He/+/ by Ne.

    NASA Technical Reports Server (NTRS)

    Bobbio, S. M.; Doverspike, L. D.; Champion, R. L.

    1973-01-01

    The perturbation seen in the experimental differential elastic-scattering cross section for the 40-eV He/+/ + Ne system has been attributed to a single crossing of two intermolecular potential-energy curves. A new theoretical treatment of the curve-crossing problem, namely, that of Delos and Thorson, is employed to obtain the crossing probabilities and phases associated with the crossing. These are determined by utilizing ab initio potentials involved in the crossing and are further used in a partial-wave calculation of the cross section, which is compared with our experiment. The origin of the oscillatory structure observed in the differential cross section is discussed in semiclassical terms by defining the problem in terms of two pseudo-deflection-functions. A rainbow effect is shown to be related to a particular feature (a maximum rather than a minimum) of these deflection functions.

  5. Stress optimization of leaf-spring crossed flexure pivots for an active Gurney flap mechanism

    NASA Astrophysics Data System (ADS)

    Freire Gómez, Jon; Booker, Julian D.; Mellor, Phil H.

    2015-04-01

    The EU's Green Rotorcraft programme is pursuing the development of a functional and airworthy Active Gurney Flap (AGF) for a full-scale helicopter rotor blade. Interest in the development of this `smart adaptive rotor blade' technology lies in its potential to provide a number of aerodynamic benefits, which would in turn translate into a reduction in fuel consumption and noise levels. The AGF mechanism selected employs leaf-spring crossed flexure pivots. These provide important advantages over bearings as they are not susceptible to seizing and do not require maintenance (i.e. lubrication or cleaning). A baseline design of this mechanism was successfully tested both in a fatigue rig and in a 2D wind tunnel environment at flight-representative deployment schedules. For full validation, a flight test would also be required. However, the severity of the in-flight loading conditions would likely compromise the mechanical integrity of the pivots' leaf-springs in their current form. This paper investigates the scope for stress reduction through three-dimensional shape optimization of the leaf-springs of a generic crossed flexure pivot. To this end, a procedure combining a linear strain energy formulation, a parametric leaf-spring profile definition and a series of optimization algorithms is employed. The resulting optimized leaf-springs are proven to be not only independent of the angular rotation at which the pivot operates, but also linearly scalable to leaf-springs of any length, minimum thickness and width. Validated using non-linear finite element analysis, the results show very significant stress reductions relative to pivots with constant cross section leaf-springs, of up to as much as 30% for the specific pivot configuration employed in the AGF mechanism. It is concluded that shape optimization offers great potential for reducing stress in crossed flexure pivots and, consequently, for extending their fatigue life and/or rotational range.

  6. $p/bar{p}$ Cross Sections for the Tevatron Energy Scan

    SciTech Connect

    Goldschmidt, Nathan; /Fermilab

    2011-01-01

    The Tevatron energy scan will present unique operational challenges for the CDF detector as a whole and the CLC luminosity detector in particular. The primary concern for CLC operations is the energy dependence of the p{bar p} cross section. In this note, values for the hadronic p{bar p} cross section at the center-of-mass energies to be visited during the scan are tabulated.

  7. Energy Activities for Junior High Science.

    ERIC Educational Resources Information Center

    Beaver, David; And Others

    This document is a collection of six energy education activities for junior high school science. Its purpose is to help promote knowledge about energy, provide laboratory experiences, provoke inquiry, and relate energy to society through the science curriculum. The six activities are designed to take one to three class periods. Two of the…

  8. Crossing Active Faults on the Sakhalin II Onshore Pipeline Route: Analysis Methodology and Basic Design

    NASA Astrophysics Data System (ADS)

    Vitali, Luigino; Mattiozzi, Pierpaolo

    2008-07-01

    Twin oil (20 & 24 inch) and gas (20 & 48 inch) pipeline systems stretching 800 km are being constructed to connect offshore hydrocarbon deposits from the Sakhalin II concession in the North to an LNG plant and oil export terminal in the South of Sakhalin island. The onshore pipeline route follows a regional fault zone and crosses individual active faults at 19 locations. Sakhalin Energy, Design and Construction companies took significant care to ensure the integrity of the pipelines, should large seismic induced ground movements occur during the Operational life of the facilities. Complex investigations including the identification of the active faults, their precise location, their particular displacement values and assessment of the fault kinematics were carried out to provide input data for unique design solutions. Lateral and reverse offset displacements of 5.5 and 4.5 m respectively were determined as the single-event values for the design level earthquake (DLE)—the 1000-year return period event. Within the constraints of a pipeline route largely fixed, the underground pipeline fault crossing design was developed to define the optimum routing which would minimize stresses and strain using linepipe materials which had been ordered prior to the completion of detailed design, and to specify requirements for pipe trenching shape, materials, drainage system, etc. This Paper describes the steps followed to formulate the concept of the special trenches and the analytical characteristics of the Model.

  9. Crossing Active Faults on the Sakhalin II Onshore Pipeline Route: Pipeline Design and Risk Analysis

    NASA Astrophysics Data System (ADS)

    Mattiozzi, Pierpaolo; Strom, Alexander

    2008-07-01

    Twin oil (20 & 24 inch) and gas (20 & 48 inch) pipeline systems stretching 800 km are being constructed to connect offshore hydrocarbon deposits from the Sakhalin II concession in the North to an LNG plant and oil export terminal in the South of Sakhalin island. The onshore pipeline route follows a regional fault zone and crosses individual active faults at 19 locations. Sakhalin Energy, Design and Construction companies took significant care to ensure the integrity of the pipelines, should large seismic induced ground movements occur during the Operational life of the facilities. Complex investigations including the identification of the active faults, their precise location, their particular displacement values and assessment of the fault kinematics were carried out to provide input data for unique design solutions. Lateral and reverse offset displacements of 5.5 and 4.5 m respectively were determined as the single-event values for the design level earthquake (DLE)—the 1000-year return period event. Within the constraints of a pipeline route largely fixed, the underground pipeline fault crossing design was developed to define the optimum routing which would minimize stresses and strain using linepipe materials which had been ordered prior to the completion of detailed design, and to specify requirements for pipe trenching shape, materials, drainage system, etc. Detailed Design was performed with due regard to actual topography and to avoid the possibility of the trenches freezing in winter, the implementation of specific drainage solutions and thermal protection measures.

  10. Crossing Active Faults on the Sakhalin II Onshore Pipeline Route: Analysis Methodology and Basic Design

    SciTech Connect

    Vitali, Luigino; Mattiozzi, Pierpaolo

    2008-07-08

    Twin oil (20 and 24 inch) and gas (20 and 48 inch) pipeline systems stretching 800 km are being constructed to connect offshore hydrocarbon deposits from the Sakhalin II concession in the North to an LNG plant and oil export terminal in the South of Sakhalin island. The onshore pipeline route follows a regional fault zone and crosses individual active faults at 19 locations. Sakhalin Energy, Design and Construction companies took significant care to ensure the integrity of the pipelines, should large seismic induced ground movements occur during the Operational life of the facilities. Complex investigations including the identification of the active faults, their precise location, their particular displacement values and assessment of the fault kinematics were carried out to provide input data for unique design solutions. Lateral and reverse offset displacements of 5.5 and 4.5 m respectively were determined as the single-event values for the design level earthquake (DLE)--the 1000-year return period event. Within the constraints of a pipeline route largely fixed, the underground pipeline fault crossing design was developed to define the optimum routing which would minimize stresses and strain using linepipe materials which had been ordered prior to the completion of detailed design, and to specify requirements for pipe trenching shape, materials, drainage system, etc. This Paper describes the steps followed to formulate the concept of the special trenches and the analytical characteristics of the Model.

  11. Crossing Active Faults on the Sakhalin II Onshore Pipeline Route: Pipeline Design and Risk Analysis

    SciTech Connect

    Mattiozzi, Pierpaolo; Strom, Alexander

    2008-07-08

    Twin oil (20 and 24 inch) and gas (20 and 48 inch) pipeline systems stretching 800 km are being constructed to connect offshore hydrocarbon deposits from the Sakhalin II concession in the North to an LNG plant and oil export terminal in the South of Sakhalin island. The onshore pipeline route follows a regional fault zone and crosses individual active faults at 19 locations. Sakhalin Energy, Design and Construction companies took significant care to ensure the integrity of the pipelines, should large seismic induced ground movements occur during the Operational life of the facilities. Complex investigations including the identification of the active faults, their precise location, their particular displacement values and assessment of the fault kinematics were carried out to provide input data for unique design solutions. Lateral and reverse offset displacements of 5.5 and 4.5 m respectively were determined as the single-event values for the design level earthquake (DLE) - the 1000-year return period event. Within the constraints of a pipeline route largely fixed, the underground pipeline fault crossing design was developed to define the optimum routing which would minimize stresses and strain using linepipe materials which had been ordered prior to the completion of detailed design, and to specify requirements for pipe trenching shape, materials, drainage system, etc. Detailed Design was performed with due regard to actual topography and to avoid the possibility of the trenches freezing in winter, the implementation of specific drainage solutions and thermal protection measures.

  12. 57Co (n,γ) 58Co reaction cross section: Thermal and resonance integral measurements and energy dependence

    NASA Astrophysics Data System (ADS)

    Maidana, Nora L.; Mesa, Joel; Vanin, Vito R.; Castro, Ruy M.; Dias, Mauro S.; Koskinas, Marina F.

    2004-07-01

    The 57Co (n,γ) 58Co thermal and resonance integral cross section were measured as 51 (5) b and 20.0 (19) b , respectively, by irradiating aliquots of 57Co solution sealed inside quartz bottles near the core of the IEA-R1 IPEN research reactor and counting the gamma-ray residual activity. The irradiations were monitored using Au-Al alloy foils, with and without Cd cover. The gamma-ray measurements were performed with a shielded HPGe detector. Westcott formalism was applied for the average neutron flux determination. The cross section energy dependence was evaluated using the multilevel Breit-Wigner expression considering the first two resonances and the statistical model for energies above the second resonance. Maxwellian averaged neutron capture cross section with neutron temperatures between 5 and 100 keV were also evaluated.

  13. {sup 57}Co(n,{gamma}){sup 58}Co reaction cross section: Thermal and resonance integral measurements and energy dependence

    SciTech Connect

    Maidana, Nora L.; Mesa, Joel; Vanin, Vito R.; Castro, Ruy M.; Dias, Mauro S.; Koskinas, Marina F.

    2004-07-01

    The {sup 57}Co(n,{gamma}){sup 58}Co thermal and resonance integral cross section were measured as 51(5) b and 20.0(19) b, respectively, by irradiating aliquots of {sup 57}Co solution sealed inside quartz bottles near the core of the IEA-R1 IPEN research reactor and counting the gamma-ray residual activity. The irradiations were monitored using Au-Al alloy foils, with and without Cd cover. The gamma-ray measurements were performed with a shielded HPGe detector. Westcott formalism was applied for the average neutron flux determination. The cross section energy dependence was evaluated using the multilevel Breit-Wigner expression considering the first two resonances and the statistical model for energies above the second resonance. Maxwellian averaged neutron capture cross section with neutron temperatures between 5 and 100 keV were also evaluated.

  14. Energy Conservation Activity Packet, Grade 5.

    ERIC Educational Resources Information Center

    Bakke, Ruth

    This activity packet for grade 5 is one of a series developed in response to concern for energy conservation. It contains activities that stress an energy conservation ethic and includes many values clarification activities for grade five. The packet is divided into two parts and provides the teacher with background information, concepts and…

  15. Photon gluon fusion cross sections at HERA energy

    NASA Astrophysics Data System (ADS)

    Engelen, J. J.; Dejong, S. J.; Poletiek, M.; Vermaseren, J. A. M.

    1988-01-01

    Cross sections for heavy flavor production through photon gluon fusion in electron proton collisions are presented. The electron photon vertex is taken into account explicitly, and the Q sq of the exchanged photon ranges from nearly zero (almost real photon) to the kinematically allowed maximum. The QCD scale is set by the mass of the produced quarks. The formalism is also applicable to the production of light quarks as long as the invariant mass of the pair is sufficiently high, so cross sections for u anti-u, d anti-d, and s anti-s production are also given.

  16. Techniques for Promoting Active Learning. The Cross Papers.

    ERIC Educational Resources Information Center

    Cross, K. Patricia

    This guide offers suggestions for implementing active learning techniques in the community college classroom. The author argues that, although much of the literature on active learning emphasizes collaboration and small-group learning, active learning does not always involve interaction. It must also involve reflection and self-monitoring of both…

  17. Dynamical thresholds and quantum undulations in the energy dependence of rotationally inelastic integral cross sections

    SciTech Connect

    Schinke, R.

    1981-12-01

    We report the observation of distinct structures in the energy dependence of rotationally inelastic integral cross sections for the systems He--Na/sub 2/ and Ne--Na/sub 2/. The calculations are performed within the infinite-order-sudden and the coupled states approximation using accurate ab initio potential energy surfaces. The integral cross section for a 0..-->..j' transition typically rises steeply at low energies, reaches a maximum, and declines slowly to the high energy region showing more or less pronounced quantum undulations. The onset of the cross section is determined by dynamical constraints rather than energy conservation. All structures in the integral cross sections are explained in terms of the energy dependence of rotational rainbow features in the corresponding differential cross sections. In particular, the undulations at higher energies stem from the supernumerary rotational rainbows. In this sense they are interpreted as analogous to the glory maxima in the elastic integral cross section for scattering from isotropic potentials. The observed structures are sensitive to the anisotropy of the repulsive branch of the potential energy surface.

  18. Total reaction cross sections in CEM and MCNP6 at intermediate energies

    SciTech Connect

    Kerby, Leslie M.; Mashnik, Stepan G.

    2015-05-14

    Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region (50 MeV to 5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used in the preequilibrium and evaporation stages of CEM are based on the Dostrovsky et al. model, published in 1959. Better cross section models are now available. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results.

  19. Low-Energy Neutrino Cross-Section Measurements at SNS

    NASA Astrophysics Data System (ADS)

    Stancu, Ion

    2006-05-01

    We discuss the proposal to build a neutrino facility at the Spallation Neutron Source (SNS) presently under construction at the Oak Ridge National Laboratory (ORNL). This facility can host an extensive, long-term program to study neutrino-nucleus cross-sections in the range of interest for nuclear astrophysics and nuclear theory.

  20. Activation cross sections for reactions induced by 14 MeV neutrons on natural tantalum

    SciTech Connect

    Luo Junhua; Tuo Fei; Kong Xiangzhong

    2009-05-15

    Cross sections for (n,2n), (n,p), (n,n{sup '}{alpha}), (n,t), (n,d{sup '}), and (n,{alpha}) reactions have been measured on tantalum isotopes at the neutron energies of 13.5 to 14.7 MeV using the activation technique. Data are reported for the following reactions: {sup 181}Ta(n,2n){sup 180}Ta{sup g}, {sup 181}Ta(n,p){sup 181}Hf, {sup 181}Ta(n,n{sup '}{alpha}){sup 177}Lu{sup m}, {sup 181}Ta(n,t){sup 179}Hf{sup m2}, {sup 181}Ta(n,d{sup '}){sup 180}Hf{sup m}, and {sup 181}Ta(n,{alpha}){sup 178}Lu{sup m}. The neutron fluences were determined using the monitor reaction {sup 27}Al(n,{alpha}){sup 24}Na. Results were discussed and compared with the previous works.

  1. Alpha capture reaction cross section measurements on Sb isotopes by activation method

    NASA Astrophysics Data System (ADS)

    Korkulu, Z.; Özkan, N.; Kiss, G. G.; Szücs, T.; Fülöp, Zs; Güray, R. T.; Gyürky, Gy; Halász, Z.; Somorjai, E.; Török, Zs; Yalçin, C.

    2016-01-01

    Alpha induced reactions on natural and enriched antimony targets were investigated via the activation technique in the energy range from 9.74 MeV to 15.48 MeV, close to the upper end of the Gamow window at a temperature of 3 GK relevant to the γ-process. The experiments were carried out at the Institute for Nuclear Research, the Hungarian Academy of Sciences (MTA Atomki). 121Sb(α,γ)125I, 121Sb(α,n)124I and 123Sb(α,n)126I reactions were measured using a HPGe detector. In this work, the 121Sb(α,n)124 cross section results and the comparison with the theoretical predictions (obtained with standard settings of the statistical model codes NON-SMOKER and TALYS) were presented.

  2. The Relationship between Cross-Culture Communication Activities and Student Motivation in Studying Second Language

    ERIC Educational Resources Information Center

    Youssef, Hussein Zanaty Mohammed

    2009-01-01

    The purpose of this study was to examine the positive impact of second language learners' cross-cultural awareness in the target language. More specifically, the pedagogical desired outcomes include: (1) exploring how students can increase their motivation in learning a foreign language by engaging in the cross-cultural activity "Sister School…

  3. Cross-Linguistic Activation in Bilingual Sentence Processing: The Role of Word Class Meaning

    ERIC Educational Resources Information Center

    Baten, Kristof; Hofman, Fabrice; Loeys, Tom

    2011-01-01

    This study investigates how categorial (word class) semantics influences cross-linguistic interactions when reading in L2. Previous homograph studies paid little attention to the possible influence of different word classes in the stimulus material on cross-linguistic activation. The present study examines the word recognition performance of…

  4. Lecturers' Perception of Research Activities for Knowledge Production in Universities in Cross River State, Nigeria

    ERIC Educational Resources Information Center

    Uchendu, C. C.; Osim, R. O.; Odigwe, F. N.; Alade, F. N.

    2014-01-01

    This study examined lecturers' perception of research activities for knowledge production in universities in Cross River State, Nigeria. Two hypotheses were isolated to give direction to this investigation. 240 university lecturers were sampled from a population of 1,868 from the two universities in Cross River State, using stratified random…

  5. Intrinsic free energy in active nematics

    NASA Astrophysics Data System (ADS)

    Thampi, Sumesh P.; Doostmohammadi, Amin; Golestanian, Ramin; Yeomans, Julia M.

    2015-10-01

    Basing our arguments on the theory of active liquid crystals, we demonstrate, both analytically and numerically, that the activity can induce an effective free energy which enhances ordering in extensile systems of active rods and in contractile suspensions of active discs. We argue that this occurs because any ordering fluctuation is enhanced by the flow field it produces. A phase diagram in the temperature-activity plane compares ordering due to a thermodynamic free energy to that resulting from the activity. We also demonstrate that activity can drive variations in concentration, but for a different physical reason that relies on the separation of hydrodynamic and diffusive time scales.

  6. Quantifying the Level of Cross-State Renewable Energy Transactions (Presentation)

    SciTech Connect

    Heeter, J.; Beiter, P.; Flores, F.; Hurlbut, D.; Liu, C.

    2015-02-01

    This presentation and associated spreadsheet examine the level of cross-state renewable energy transactions. Most state renewable portfolio standard (RPS) policies allow for out-of-state renewable energy or renewable energy certificates to count towards compliance. This analysis focuses on compliance for 2012 and provides stakeholders with an understanding of the extent to which RPSs are being met.

  7. Safety enhancement of oil trunk pipeline crossing active faults on Sakhalin Island

    NASA Astrophysics Data System (ADS)

    Tishkina, E.; Antropova, N.; Korotchenko, T.

    2015-11-01

    The article explores the issues concerning safety enhancement of pipeline active fault crossing on Sakhalin Island. Based on the complexity and analysis results, all the faults crossed by pipeline system are classified into five categories - from very simple faults to extremely complex ones. The pipeline fault crossing design is developed in accordance with the fault category. To enhance pipeline safety at fault crossing, a set of methods should be applied: use of pipes of different safety classes and special trench design in accordance with soil permeability characteristics.

  8. Understanding Tensions: Activity Systems Analysis of Cross-Continental Collaboration

    ERIC Educational Resources Information Center

    Ryder, LanHui Zhang; Yamagata-Lynch, Lisa

    2014-01-01

    Using the lens of Vygotsky's sociocultural theory, activity theory, and Engeström's activity systems analysis, this qualitative study explores students' experiences in the context of a sixteen-week transpacific collaboration between seven students at Northern Illinois University (NIU) and seven students from Shandong Normal…

  9. Fragmentation cross sections and binding energies of neutron-rich nuclei

    NASA Astrophysics Data System (ADS)

    Tsang, M. B.; Lynch, W. G.; Friedman, W. A.; Mocko, M.; Sun, Z. Y.; Aoi, N.; Cook, J. M.; Delaunay, F.; Famiano, M. A.; Hui, H.; Imai, N.; Iwasaki, H.; Motobayashi, T.; Niikura, M.; Onishi, T.; Rogers, A. M.; Sakurai, H.; Suzuki, H.; Takeshita, E.; Takeuchi, S.; Wallace, M. S.

    2007-10-01

    An exponential dependence of the fragmentation cross section on the average binding energy is observed and reproduced with a statistical model. The observed functional dependence is robust and allows the extraction of binding energies from measured cross sections. From the systematics of Cu isotope cross sections, the binding energies of Cu76,77,78,79 have been extracted. They are 636.94±0.4,647.1±0.4,651.6±0.4, and 657.8±0.5 MeV, respectively. Specifically, the uncertainty of the binding energy of Cu75 is reduced from 980 keV, as listed in the 2003 mass table of Audi, Wapstra, and Thibault to 400 keV. The predicted cross sections of two near drip-line nuclei, Na39 and Mg40 from the fragmentation of Ca48 are discussed.

  10. Fragmentation cross sections and binding energies of neutron-rich nuclei

    SciTech Connect

    Tsang, M. B.; Lynch, W. G.; Mocko, M.; Cook, J. M.; Delaunay, F.; Famiano, M. A.; Hui, H.; Rogers, A. M.; Wallace, M. S.; Friedman, W. A.; Sun, Z. Y.; Aoi, N.; Imai, N.; Motobayashi, T.; Takeuchi, S.; Iwasaki, H.; Onishi, T.; Sakurai, H.; Suzuki, H.; Niikura, M.

    2007-10-15

    An exponential dependence of the fragmentation cross section on the average binding energy is observed and reproduced with a statistical model. The observed functional dependence is robust and allows the extraction of binding energies from measured cross sections. From the systematics of Cu isotope cross sections, the binding energies of {sup 76,77,78,79}Cu have been extracted. They are 636.94{+-}0.4,647.1{+-}0.4,651.6{+-}0.4, and 657.8{+-}0.5 MeV, respectively. Specifically, the uncertainty of the binding energy of {sup 75}Cu is reduced from 980 keV, as listed in the 2003 mass table of Audi, Wapstra, and Thibault to 400 keV. The predicted cross sections of two near drip-line nuclei, {sup 39}Na and {sup 40}Mg from the fragmentation of {sup 48}Ca are discussed.

  11. Low-energy electron elastic scattering cross sections for excited Au and Pt atoms

    NASA Astrophysics Data System (ADS)

    Felfli, Zineb; Eure, Amanda R.; Msezane, Alfred Z.; Sokolovski, Dmitri

    2010-05-01

    Electron elastic total cross sections (TCSs) and differential cross sections (DCSs) in both impact energy and scattering angle for the excited Au and Pt atoms are calculated in the electron impact energy range 0 ⩽ E ⩽ 4.0 eV. The cross sections are found to be characterized by very sharp long-lived resonances whose positions are identified with the binding energies of the excited anions formed during the collisions. The recent novel Regge-pole methodology wherein is embedded through the Mulholland formula the electron-electron correlations is used together with a Thomas-Fermi type potential incorporating the crucial core-polarization interaction for the calculations of the TCSs. The DCSs are evaluated using a partial wave expansion. The Ramsauer-Townsend minima, the shape resonances and the binding energies of the excited Au - and Pt - anions are extracted from the cross sections, while the critical minima are determined from the DCSs.

  12. Barrier Crossing and Transport Activated by Kangaroo Fluctuations

    NASA Astrophysics Data System (ADS)

    Kostur, M.; Luczka, J.

    1999-01-01

    We study barrier crossing of Brownian particles in a bistable symmetric potential and transport of Brownian particles in spatially periodic structures, driven by both kangaroo fluctuations and thermal equilibrium noise of zero mean values. We consider exponentially and algebraically correlated kangaroo fluctuations. Starting with the full Newton--Langevin equation for the Brownian particle and by introducing scaling as well as dimensionless variables, we show that the equation is very well approximated by overdamped dynamics in which inertial effects can be neglected. We analyze properties of selected macroscopic characteristics of the system such as the mean first passage time (MFPT) of particles from one minimum of the bistable potential to the other and mean stationary velocity of particles moving in a spatially periodic potential. In dependence upon statistics of kangaroo fluctuations and temperature of the system, macroscopic characteristics exhibit distinctive non-monotonic behavior. Accordingly, there exist optimal statistics of fluctuations optimizing macroscopic characteristics.

  13. Activation Cross-Sections for 14.2 MeV Neutrons on Molybdenum

    NASA Astrophysics Data System (ADS)

    Srinivasa Rao, C. V.; Lakshmana Das, N.; Thirumala Rao, B. V.; Rama Rao, J.

    1981-12-01

    Using the activation method, the cross-section for the following reactions on molybdenum were measured employing the mixed powder technique and Ge(Li) gamma-ray spectroscopy: 94Mo(n, 2n)93mMo, 3.5 ± 0.5 mbarn; 92Mo(n, 2n)91mMo, 19 ± 3 mbarn; 92Mo(n, 2n)91m+gMo, 226 ± 11 mbarn; 100Mo(n, p)100m2Nb, 9 ± 1 mbarn; 98Mo(n, p)98Nb, 10 ± 1 mbarn; 97Mo(n, p)97mNb, 5 ± 1 mbarn; 96Mo(n, p)96Nb, 12 ± 2 mbarn; 92Mo(n, α)89mZr, 2.1 ± 0.5 mbarn; and 92Mo(n, α)89m+gZr 24 ± 6 mbarn; the neutron energy was 14.2 ± 0.2 MeV. The experimental cross-sections were compared with the predictions of evaporation model and of different versions of pre-equilibrium model. The master equation approach appears to give satisfactory results.

  14. Tuning the implosion symmetry of ICF targets via controlled crossed-beam energy transfer

    SciTech Connect

    Michel, P; Divol, L; Williams, E; Weber, S; Thomas, C A; Callahan, D A; Haan, S W; Salmonson, J D; Dixit, S; Hinkel, D E; Edwards, M J; MacGowan, B J; Lindl, J D; Glenzer, S H; Suter, L

    2008-07-29

    Radiative hydrodynamics simulations of ignition experiments show that energy transfer between crossing laser beams allows tuning of the implosion symmetry. A new full-scale, three dimensional quantitative model has been developed for crossed-beam energy transfer, allowing calculations of the propagation and coupling of multiple laser beams and their associated plasma waves in ignition hohlraums. This model has been implemented in a radiative-hydrodynamics code, demonstrating control of the implosion symmetry by a wavelength separation between cones of laser beams.

  15. Measurements of ultra-low-energy electron scattering cross sections of atoms and molecules

    SciTech Connect

    Kitajima, M.; Shigemura, K.; Kurokawa, M.; Odagiri, T.; Kato, H.; Hoshino, M.; Tanaka, H.; Ito, K.

    2014-03-05

    A new experimental technique for the total cross section measurements of ultra-low energy electron collisions with atoms and molecules utilizing the synchrotron radiation is presented. The technique employs a combination of the penetrating field technique and the threshold photoionization of rare gas atoms using the synchrotron radiation as an electron source in order to produce a high resolution electron beam at very low energy. Absolute total cross sections for electron scattering from He, Ne, Ar, Kr, and Xe in the energy region from extremely low electron energy to 20 eV are presented.

  16. The energy distribution cross section in threshold electron-atom impact ionization

    NASA Technical Reports Server (NTRS)

    Temkin, A.

    1974-01-01

    The flatness of the energy differential cross section in impact ionization is derived analytically in the Wannier theory. However it is shown that the Wannier zone is confined to a region of the order E/5 is less than or equal to epsilon is less than or equal to 4E/5, where E is the available energy and epsilon is the energy of the electrons. By contrasting the known results of photoionization and photodetachment, one can cogently argue that in the complementary region where electrons share their energy very unequally the cross section rises to a value independent of E, and that this region determines the form of the threshold law.

  17. Solar energy education. Renewable energy activities for general science

    SciTech Connect

    Not Available

    1985-01-01

    Renewable energy topics are integrated with the study of general science. The literature is provided in the form of a teaching manual and includes such topics as passive solar homes, siting a home for solar energy, and wind power for the home. Other energy topics are explored through library research activities. (BCS)

  18. Solar Energy Education. Renewable energy activities for biology

    SciTech Connect

    Not Available

    1982-01-01

    An instructional aid for teachers is presented that will allow biology students the opportunity to learn about renewable energy sources. Some of the school activities include using leaves as collectors of solar energy, solar energy stored in wood, and a fuel value test for green and dry woods. A study of organic wastes as a source of fuel is included. (BCS)

  19. Parameter-free calculation of charge-changing cross sections at high energy

    NASA Astrophysics Data System (ADS)

    Suzuki, Y.; Horiuchi, W.; Terashima, S.; Kanungo, R.; Ameil, F.; Atkinson, J.; Ayyad, Y.; Cortina-Gil, D.; Dillmann, I.; Estradé, A.; Evdokimov, A.; Farinon, F.; Geissel, H.; Guastalla, G.; Janik, R.; Knoebel, R.; Kurcewicz, J.; Litvinov, Yu. A.; Marta, M.; Mostazo, M.; Mukha, I.; Nociforo, C.; Ong, H. J.; Pietri, S.; Prochazka, A.; Scheidenberger, C.; Sitar, B.; Strmen, P.; Takechi, M.; Tanaka, J.; Tanihata, I.; Vargas, J.; Weick, H.; Winfield, J. S.

    2016-07-01

    Charge-changing cross sections at high energies are expected to provide useful information on nuclear charge radii. No reliable theory to calculate the cross section has yet been available. We develop a formula using Glauber and eikonal approximations and test its validity with recent new data on carbon isotopes measured at around 900 A MeV. We first confirm that our theory reproduces the cross sections of 12,13,14C+12C consistently with the known charge radii. Next we show that the cross sections of C-1912 on a proton target are all well reproduced provided the role of neutrons is accounted for. We also discuss the energy dependence of the charge-changing cross sections.

  20. Energy-efficiency testing activities of the Mobile Energy Laboratory

    SciTech Connect

    Parker, G.B.

    1991-01-01

    This report summarizes energy-efficiency testing activities during the first and second quarters of fiscal year 1990 applying the Mobile Energy Laboratory (MEL) testing capabilities. Four MELs, developed by the US Department of Energy (DOE) Federal Energy Management Program (FEMP), are administered by Pacific Northwest Laboratory (PNL) for energy testing and program support functions at federal facilities. The using agencies principally fund MEL applications, while DOE/FEMP funds program administration and capability enhancement activities. This report fulfills the requirements established in the MEL Use Plan (PNL-6861) for semiannual reporting on energy-efficiency testing activities using the MEL capabilities. The MEL Use Committee, formally established in 1989, developed the MEL Use Plan and meets semiannually to establish priorities for energy-efficient testing applications using the MEL capabilities.

  1. On two-parameter models of photon cross sections: Application to dual-energy CT imaging

    SciTech Connect

    Williamson, Jeffrey F.; Li Sicong; Devic, Slobodan; Whiting, Bruce R.; Lerma, Fritz A.

    2006-11-15

    The goal of this study is to evaluate the theoretically achievable accuracy in estimating photon cross sections at low energies (20-1000 keV) from idealized dual-energy x-ray computed tomography (CT) images. Cross-section estimation from dual-energy measurements requires a model that can accurately represent photon cross sections of any biological material as a function of energy by specifying only two characteristic parameters of the underlying material, e.g., effective atomic number and density. This paper evaluates the accuracy of two commonly used two-parameter cross-section models for postprocessing idealized measurements derived from dual-energy CT images. The parametric fit model (PFM) accounts for electron-binding effects and photoelectric absorption by power functions in atomic number and energy and scattering by the Klein-Nishina cross section. The basis-vector model (BVM) assumes that attenuation coefficients of any biological substance can be approximated by a linear combination of mass attenuation coefficients of two dissimilar basis substances. Both PFM and BVM were fit to a modern cross-section library for a range of elements and mixtures representative of naturally occurring biological materials (Z=2-20). The PFM model, in conjunction with the effective atomic number approximation, yields estimated the total linear cross-section estimates with mean absolute and maximum error ranges of 0.6%-2.2% and 1%-6%, respectively. The corresponding error ranges for BVM estimates were 0.02%-0.15% and 0.1%-0.5%. However, for photoelectric absorption frequency, the PFM absolute mean and maximum errors were 10.8%-22.4% and 29%-50%, compared with corresponding BVM errors of 0.4%-11.3% and 0.5%-17.0%, respectively. Both models were found to exhibit similar sensitivities to image-intensity measurement uncertainties. Of the two models, BVM is the most promising approach for realizing dual-energy CT cross-section measurement.

  2. Solar Energy Project, Activities: General Solar Topics.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of activities which introduce students to concepts and issues relating to solar energy. Lessons frequently presented in the context of solar energy as it relates to contemporary energy problems. Each unit presents an introduction; objectives; necessary skills and knowledge; materials; method;…

  3. New data on activation cross section for deuteron induced reactions on ytterbium up to 50 MeV

    NASA Astrophysics Data System (ADS)

    Tárkányi, F.; Ditrói, F.; Takács, S.; Hermanne, A.; Ignatyuk, A. V.

    2014-10-01

    Activation cross sections of deuteron induced reactions on ytterbium for production of 177g,173,172,171,170,169,167Lu, 177,175,169Yb and 173,168,167,165Tm were extended up to 50 MeV deuteron energy. The new data are in acceptable agreement with the earlier experimental data in the overlapping energy region. The experimental data are compared with the predictions of the ALICE-D, EMPIRE-D and TALYS 1.4 (TENDL-2013 on-line library results) codes.

  4. Titanium spallation cross sections between 30 and 584 MeV and Ar-39 activities on the moon

    NASA Technical Reports Server (NTRS)

    Steinbrunn, F.; Fireman, E. L.

    1974-01-01

    The production cross sections of Ar-39 for Ti spallation at 45-, 319-, 433-, and 584-MeV proton energies were measured to be 0.37 + or - 09, 12.4 + or - 3.7, 9.1 + or - 2.7, and 17.8 + or - 6.2 mb, respectively. Normalized Ar-39 production rates and activities are also derived for protons above 40 Mev and for three differential proton spectra. It is concluded that even for samples of high-Ti content, Ti spallation by solar protons below 200-MeV energy does not contribute significantly to their Ar-39 radioactivity.

  5. EuropeaN Energy balance Research to prevent excessive weight Gain among Youth (ENERGY) project: Design and methodology of the ENERGY cross-sectional survey

    PubMed Central

    2011-01-01

    Background Obesity treatment is by large ineffective long term, and more emphasis on the prevention of excessive weight gain in childhood and adolescence is warranted. To inform energy balance related behaviour (EBRB) change interventions, insight in the potential personal, family and school environmental correlates of these behaviours is needed. Studies on such multilevel correlates of EBRB among schoolchildren in Europe are lacking. The ENERGY survey aims to (1) provide up-to-date prevalence rates of measured overweight, obesity, self-reported engagement in EBRBs, and objective accelerometer-based assessment of physical activity and sedentary behaviour and blood-sample biomarkers of metabolic function in countries in different regions of Europe, (2) to identify personal, family and school environmental correlates of these EBRBs. This paper describes the design, methodology and protocol of the survey. Method/Design A school-based cross-sectional survey was carried out in 2010 in seven different European countries; Belgium, Greece, Hungary, the Netherlands, Norway, Slovenia, and Spain. The survey included measurements of anthropometrics, child, parent and school-staff questionnaires, and school observations to measure and assess outcomes (i.e. height, weight, and waist circumference), EBRBs and potential personal, family and school environmental correlates of these behaviours including the social-cultural, physical, political, and economic environmental factors. In addition, a selection of countries conducted accelerometer measurements to objectively assess physical activity and sedentary behaviour, and collected blood samples to assess several biomarkers of metabolic function. Discussion The ENERGY survey is a comprehensive cross-sectional study measuring anthropometrics and biomarkers as well as assessing a range of EBRBs and their potential correlates at the personal, family and school level, among 10-12 year old children in seven European countries. This study

  6. The Role of Cross-Language Activation in Syntactic Ambiguity

    ERIC Educational Resources Information Center

    Yeh, Li-Hao

    2011-01-01

    There is much evidence demonstrating that bilinguals activate lexical representations from both of their languages in a non-selective manner even in sentence context. Comparatively less research has examined the extent to which bilingual lexical representations interacts with syntactic processing in sentence context. The purpose of this study is…

  7. Cross-Language Activation of Phonology in Young Bilingual Readers

    ERIC Educational Resources Information Center

    Jared, Debra; Cormier, Pierre; Levy, Betty Ann; Wade-Woolley, Lesly

    2012-01-01

    We investigated whether children who were learning to read simultaneously in English and French activate phonological representations from only the language in which they are reading or from both of their languages. Children in French Immersion programs in Grade 3 were asked to name aloud cognates, interlingual homographs, interlingual homophones,…

  8. Measurements of the proton-air cross section with high energy cosmic ray experiments

    NASA Astrophysics Data System (ADS)

    Abbasi, Rasha

    2016-07-01

    Detecting Ultra High Energy Cosmic Rays (UHECRs) enables us to measure the proton-air inelastic cross section σinel p-air at energies that we are unable to access with particle accelerators. The proton-proton cross section σp-p is subsequently inferred from the proton-air cross section at these energies. UHECR experiments have been reportingon the proton-air inelastic cross section starting with the Fly's Eye in 1984 at √s =30 TeV and ending with the most recent result of the Telescope Array experiment at √s = 95 TeV in 2015. In this proceeding, I will summarize the most recent experimental results on the σinel p-air measurements from the UHECR experiments.

  9. Hybrid energy harvesting using active thermal backplane

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Wook; Lee, Dong-Gun

    2016-04-01

    In this study, we demonstrate the concept of a new hybrid energy harvesting system by combing solar cells with magneto-thermoelectric generator (MTG, i.e., thermal energy harvesting). The silicon solar cell can easily reach high temperature under normal operating conditions. Thus the heated solar cell becomes rapidly less efficient as the temperature of solar cell rises. To increase the efficiency of the solar cell, air or water-based cooling system is used. To surpass conventional cooling devices requiring additional power as well as large working space for air/water collectors, we develop a new technology of pairing an active thermal backplane (ATB) to solar cell. The ATB design is based on MTG technology utilizing the physics of the 2nd order phase transition of active ferromagnetic materials. The MTG is cost-effective conversion of thermal energy to electrical energy and is fundamentally different from Seebeck TEG devices. The ATB (MTG) is in addition to being an energy conversion system, a very good conveyor of heat through both conduction and convection. Therefore, the ATB can provide dual-mode for the proposed hybrid energy harvesting. One is active convective and conductive cooling for heated solar cell. Another is active thermal energy harvesting from heat of solar cell. These novel hybrid energy harvesting device have potentially simultaneous energy conversion capability of solar and thermal energy into electricity. The results presented can be used for better understanding of hybrid energy harvesting system that can be integrated into commercial applications.

  10. Large cross section for super energy transfer from hyperthermal atoms to ambient molecules

    NASA Astrophysics Data System (ADS)

    Ma, Jianqiang; Wilhelm, Michael J.; Smith, Jonathan M.; Dai, Hai-Lung

    2016-04-01

    The experimentally measured cross section for super energy transfer collisions between a hyperthermal H atom and an ambient molecule is presented here. This measurement substantiates an emerging energy transfer mechanism with significant cross section, whereby a major fraction of atomic translational energy is converted into molecular vibrational energy through a transient collision-induced reactive complex. Specifically, using nanosecond time-resolved infrared emission spectroscopy, it is revealed that collisions between hyperthermal hydrogen atoms (with 59 kcal/mol of kinetic energy) and ambient SO2 result in the production of vibrationally highly excited SO2 with >14 000 cm-1 of internal energy. The lower limit of the cross section for this super energy transfer process is determined to be 0.53 ±0.05 Å2, i.e., 2% of all hard-sphere collisions. This cross section is orders of magnitude greater than that predicted by the exponential energy gap law, which is commonly used for describing collisional energy transfer through repulsive interactions.

  11. Energy and Energy Conservation Activities for High School Students.

    ERIC Educational Resources Information Center

    Bottinelli, Charles A., Ed.; Dow, John O., Ed.

    This manual contains fifteen energy activities suitable for high school physical and environmental science and mathematics classrooms. The activities are independent, each having its own objectives, introduction, and background information. A special section of each activity is written for the instructor and contains limits, sample data, and…

  12. Extending the energy range of materials activation modelling

    NASA Astrophysics Data System (ADS)

    Forrest, R. A.

    2004-08-01

    Activation calculations are an essential contribution to understanding the interactions of fusion materials with neutrons. The existing state-of-the-art tools such as EASY-2003 enable calculations to be carried out with neutrons up to 20 MeV. Plans to expose fusion components to high neutron fluxes include the IFMIF materials testing facility. This accelerator-based device will produce neutrons with a high-energy tail up to about 55 MeV. In order to carry out activation calculations on materials exposed to such neutrons it is necessary to extend the energy range of the data libraries. An extension of the European Activation System (EASY) to a new version, EASY-2004, for testing has been completed. The existing reactions have been extended up to 60 MeV and new classes of reactions added using calculated cross sections. Results of preliminary calculations in an IFMIF relevant neutron field are given.

  13. Total cross sections and ρ at high energy

    NASA Astrophysics Data System (ADS)

    Selyugin, O. V.

    2014-02-01

    Analysis of the new experimental data obtained by the TOTEM Collaboration at LHC at s=7 TeV at small momentum transfer is presented. The impact of the different assumptions on the extraction of the parameters of the elastic scattering amplitude, especially on the size of the total cross sections, is examined. It is shown that the contribution of the Coulomb amplitude and Coulomb-hadron interference term should be taken into account in the analysis of the existing experimental data at small momentum transfer. Our new method of extracting the real part of the hadron scattering amplitude from experimental data shows the inconsistency of the size of ρ=0.14 to the parameters of the imaginary part of the hadron scattering amplitude obtained by the TOTEM Collaboration. The analysis of the data is compared with the similar analysis in the Regge approach for the hadron scattering amplitude.

  14. Lexical Activation in Bilinguals' Speech Production Is Dynamic: How Language Ambiguous Words Can Affect Cross-Language Activation

    ERIC Educational Resources Information Center

    Hermans, Daan; Ormel, E.; van Besselaar, Ria; van Hell, Janet

    2011-01-01

    Is the bilingual language production system a dynamic system that can operate in different language activation states? Three experiments investigated to what extent cross-language phonological co-activation effects in language production are sensitive to the composition of the stimulus list. L1 Dutch-L2 English bilinguals decided whether or not a…

  15. Energy-dependent parameterization of heavy-ion absorption cross sections

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.; Wilson, J. W.

    1986-01-01

    An energy-dependent parameterization of the total absorption (reaction) cross sections for heavy ion (Z equal to or greater than 2) collisions at energies above 25 MeV per nucleon is presented. The formula will be especially useful in heavy-ion transport applications.

  16. 75 FR 11938 - Chart Energy and Chemicals, Inc., La Crosse, WI; Notice of Termination of Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... of Machinists and Aerospace Workers, Lodge 2191, on behalf of workers of Chart Energy and Chemical... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration Chart Energy and Chemicals, Inc., La Crosse, WI; Notice of...

  17. Collision Cross Sections for O + Ar(+) Collisions in the Energy Range 0.03-500 eV.

    PubMed

    Sycheva, A A; Balint-Kurti, G G; Palov, A P

    2016-07-14

    The interatomic potentials of the a(2)Π and b(2)Π states of the OAr(+) molecule are calculated using the relativistic complete-active space Hartree-Fock method followed by a multireference configuration interaction calculation with an aug-cc-pwCVNZ-DK basis sets where N is 4 and 5. The calculations were followed by an extrapolation to the complete basis set limit. An avoided crossing between the two potential energy curves is found at an internuclear separation of 5.75 bohr (3.04 Å). As the transition probability between the curves is negligible in the relative collision energy range 0.03-500 eV of interest here, collisions on the lower adiabatic a(2)Π potential may be treated without reference to the upper state. For low energies and orbital angular momentum quantum numbers, the one-dimensional radial Schrödinger equation is solved numerically using a Numerov algorithm method to determine the phase shift. The semiclassical JWKB approximation was employed for relative energies greater than 5 eV and orbital angular quantum numbers higher than 500. Differential, integral, transport (diffusion), and viscosity cross sections for elastic collisions of oxygen atoms with argon ions are calculated for the first time for the range of relative collision energies studied. The calculated cross sections are expected to be of utility in the fields of nanotechnology and arc welding. The combination of an Ar(+)((2)P) ion and a O((3)P) atom gives rise to a total of 12 different molecular electronic states that are all coupled by spin-orbit interactions. Potential energy curves for all 12 states are computed at the complete active space self-consistent field (CASSCF) level and scattering calculations performed. The results are compared with those obtained using just the lowest potential energy curve. PMID:26741565

  18. Isoelectronic sequence fits to configuration-averaged photoionization cross sections and ionization energies

    SciTech Connect

    Clark, R.E.H.; Cowan, R.D.; Bobrowicz, F.W.

    1986-05-01

    Hartree--Fock wave functions have been used to calculate configuration -averaged photoionization cross sections and ionization energies for orbitals 1s< or =nl< or =5g in He-like through Al-like isoelectroni csequences. The photoionization cross sections have been fitted as a function of the nuclear charge, Z, and photon energy, X, in threshold units, with average error of less than 10%. The ionization energies have been fitted as a function of Z with errors of less than 0.5%

  19. An analysis of MCNP cross-sections and tally methods for low-energy photon emitters

    NASA Astrophysics Data System (ADS)

    DeMarco, John J.; Wallace, Robert E.; Boedeker, Kirsten

    2002-04-01

    Monte Carlo calculations are frequently used to analyse a variety of radiological science applications using low-energy (10-1000 keV) photon sources. This study seeks to create a low-energy benchmark for the MCNP Monte Carlo code by simulating the absolute dose rate in water and the air-kerma rate for monoenergetic point sources with energies between 10 keV and 1 MeV. The analysis compares four cross-section datasets as well as the tally method for collision kerma versus absorbed dose. The total photon attenuation coefficient cross-section for low atomic number elements has changed significantly as cross-section data have changed between 1967 and 1989. Differences of up to 10% are observed in the photoelectric cross-section for water at 30 keV between the standard MCNP cross-section dataset (DLC-200) and the most recent XCOM/NIST tabulation. At 30 keV, the absolute dose rate in water at 1.0 cm from the source increases by 7.8% after replacing the DLC-200 photoelectric cross-sections for water with those from the XCOM/NIST tabulation. The differences in the absolute dose rate are analysed when calculated with either the MCNP absorbed dose tally or the collision kerma tally. Significant differences between the collision kerma tally and the absorbed dose tally can occur when using the DLC-200 attenuation coefficients in conjunction with a modern tabulation of mass energy-absorption coefficients.

  20. Rotationally elastic total cross sections for NH3 on electron impact over a wide energy range

    NASA Astrophysics Data System (ADS)

    Vinodkumar, Minaxi; Limbachiya, Chetan; Antony, Bobby

    2011-10-01

    Electron molecule collisions are important over incident energy from very low (0.01 eV) to intermediate and high energies (10 keV). We present rotationally elastic total cross sections for electron scattering for NH3 from 0.01 eV to 2 keV using two different theoretical formalisms. We use Quantemol-N formalism for calculating total cross sections up to threshold of the target and the Spherical Optical Complex Potential (SCOP) method for calculating total cross sections beyond threshold up to 2 keV. Electron molecule collisions are important over incident energy from very low (0.01 eV) to intermediate and high energies (10 keV). We present rotationally elastic total cross sections for electron scattering for NH3 from 0.01 eV to 2 keV using two different theoretical formalisms. We use Quantemol-N formalism for calculating total cross sections up to threshold of the target and the Spherical Optical Complex Potential (SCOP) method for calculating total cross sections beyond threshold up to 2 keV. MVK and BA thank DST, CGL thanks UGC new Delhi.

  1. Effects of Nuclear Cross Sections at Different Energies on Space Radiation Exposure from Galactic Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Li, Zi-Wei; Adams, James H., Jr.

    2007-01-01

    Space radiation from galactic cosmic rays (GCR) is a major hazard to space crews, especially in long duration human space explorations. For this reason, they will be protected by radiation shielding that fragments the GCR heavy ions. Here we investigate how sensitive the crew's radiation exposure is to nuclear fragmentation cross sections at different energies. We find that in deep space cross sections between about 0.2 and 1.2 GeV/u have the strongest effect on dose equivalent behind shielding in solar minimum GCR environments, and cross sections between about 0.6 and 1.7 GeV/u are the most important at solar maximum'. On the other hand, at the location of the International Space Station, cross sections at_higher -energies, between about 0.6 and 1.7 GeV /u at solar minimum and between about 1.7 and 3.4 GeV/u'at,solar maximum, are the most important This is. due-to the average geomagnetic cutoff for the ISS orbit. We also show the effect of uncertainties in the fragmentation cross sections on the elemental energy spectra behind shielding. These results help to focus the studies of fragmentation cross sections on the proper energy range in order to improve our predictions of crew exposures.

  2. Ab initio cross sections for low-energy inelastic H+Na collisions

    NASA Astrophysics Data System (ADS)

    Belyaev, A. K.; Grosser, J.; Hahne, J.; Menzel, T.

    1999-09-01

    We report ab initio results for the integral cross section of the process H+Na(3s)-->H+Na(3p) for collision energies from the threshold (2.1 eV) to 600 eV. We achieve a reasonable agreement with the experimental data, which are available for energies above 10 eV. The main contributions to the cross section come from a rotational coupling mechanism in the NaH triplet molecular system and from a curve-crossing mechanism in the singlet system. At very low energy (2.1-2.4 eV), the process is governed by a centrifugal barrier in the exit channel leading to orbital resonances. The Landau-Zener model provides a reasonable qualitative description of the radial coupling mechanism at high energies, but fails below 10 eV.

  3. Energy dependence of breakup cross sections of the halo nucleus {sup 8}B and effective interactions

    SciTech Connect

    Bertulani, C.A.; Lotti, P.; Sagawa, H.

    1998-01-01

    We study the energy dependence of the cross sections for nucleon removal of {sup 8}B projectiles. It is shown that the Glauber model calculations with nucleon-nucleon t-matrix reproduce well the energy dependence of the breakup cross sections of {sup 8}B. A distorted wave Born approximation (DWBA) model for the breakup cross section is also proposed and results are compared with those of the Glauber model. We show that to obtain an agreement between the DWBA calculations, the Glauber formalism, and the experimental data, it is necessary to modify the energy behavior of the effective interaction. In particular, the breakup potential has a quite different energy dependence than the strong absorption potential. {copyright} {ital 1998} {ital The American Physical Society}

  4. Mindfulness and satisfaction in physical activity: A cross-sectional study in the Dutch population.

    PubMed

    Tsafou, Kalliopi-Eleni; De Ridder, Denise Td; van Ee, Raymond; Lacroix, Joyca Pw

    2016-09-01

    Both satisfaction and mindfulness relate to sustained physical activity. This study explored their relationship. We conducted a cross-sectional study with 398 Dutch participants who completed measures on trait mindfulness, mindfulness and satisfaction with physical activity, physical activity habits, and physical activity. We performed mediation and moderated mediation. Satisfaction mediated the effect of mindfulness on physical activity. Mindfulness was related to physical activity only when one's habit was weak. The relation of mindfulness with satisfaction was stronger for weak compared to strong habit. Understanding the relationship between mindfulness and satisfaction can contribute to the development of interventions to sustain physical activity. PMID:25631662

  5. Hyperspherical hidden crossing calculation of Ps formation in low-energy e+-Na collisions

    NASA Astrophysics Data System (ADS)

    Ward, S. J.; Shertzer, J.

    2011-05-01

    The hyperspherical hidden crossing method (HHCM) can provide important insight into scattering processes. Previously, we have used the HHCM to calculate the Ps(1s)-formation cross section in low-energy e+-H and e+-Li collisions. Here we apply the HHCM to low-energy e+-Na collisions. We use the Peach model potential and treat e+e-Na+ as an effective three-body system. We calculate the Ps(1s)-formation cross sections for 0 <= L <= 3 and compare our results with a hyperspherical close-coupling calculation. The HHCM provides an explanation for the small S-wave Ps(1s)-formation cross section. The S-wave Stückelberg phase is close to π for the three collision systems due to destructive interference between the two amplitudes that correspond to different paths leading to Ps(1s) formation.

  6. Effects of Nuclear Cross Sections at Different Energies on the Radiation Hazard from Galactic Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Lin, Z. W.; Adams, J. H., Jr.

    2006-01-01

    The radiation hazard for astronauts from galactic cosmic rays is a major obstacle in long duration human space explorations. Space radiation transport codes have been developed to calculate radiation environment on missions to the Moon, Mars or beyond. We have studied how uncertainties in fragmentation cross sections at different energies affect the accuracy of predictions from such radiation transport. We find that, in deep space, cross sections between 0.3 and 0.85 GeV/u usually have the largest effect on dose-equivalent behind shielding in solar minimum GCR environments, and cross sections between 0.85 and 1.2 GeV/u have the largest effect in solar maximum GCR environments. At the International Space Station, cross sections at higher energies have the largest effect due to the geomagnetic cutoff.

  7. Bcr is a substrate for Transglutaminase 2 cross-linking activity

    PubMed Central

    2011-01-01

    Background Breakpoint cluster region (Bcr) is a multi-domain protein that contains a C-terminal GTPase activating protein (GAP) domain for Rac. Transglutaminase 2 (TG2) regulates Bcr by direct binding to its GAP domain. Since TG2 has transglutaminase activity that has been implicated in the response to extreme stress, we investigated if Bcr can also act as a substrate for TG2. Results We here report that activation of TG2 by calcium caused the formation of covalently cross-linked Bcr. Abr, a protein related to Bcr but lacking its N-terminal oligomerization domain, was not cross-linked by TG2 even though it forms a complex with it. A Bcr mutant missing the first 62 amino acid residues remained monomeric in the presence of activated TG2, showing that this specific domain is necessary for the cross-linking reaction. Calcium influx induced by a calcium ionophore in primary human endothelial cells caused cross-linking of endogenous Bcr, which was inhibited by the TG2 inhibitor cystamine. Treatment of cells with cobalt chloride, a hypoxia-mimetic that causes cellular stress, also generated high molecular weight Bcr complexes. Cross-linked Bcr protein appeared in the TritonX-100-insoluble cell fraction and further accumulated in cells treated with a proteasome inhibitor. Conclusions Bcr thus represents both an interacting partner under non-stressed conditions and a target of transglutaminase activity for TG2 during extreme stress. PMID:21310073

  8. Elastic cross sections for low-energy electron collisions with tetrahydropyran

    NASA Astrophysics Data System (ADS)

    Souza Barbosa, Alessandra; Bettega, Márcio H. F.

    2016-02-01

    We report on calculated elastic cross sections for low-energy electron collisions with the cyclic ether tetrahydropyran (C5H10O). The calculations were carried out with the Schwinger multichannel method implemented with norm-conserving pseudopotentials in the static-exchange-polarization approximation for energies up to 20 eV. Our cross sections are compared with previous results obtained for cyclohexane and 1,4-dioxane, since the three molecules present similar structures. The calculated differential cross sections for these three molecules present similarities, except at low scattering angles, where the differential cross sections of tetrahydropyran present a sharp increase due to the permanent dipole moment of the molecule. The similarities observed in the cross sections reveal that the molecular geometry plays an important role in the description of scattering process. We also compared our calculated elastic integral cross section for tetrahydropyran with experimental total cross sections data available in the literature and found a good qualitative agreement between both results. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  9. Elastic cross sections for low-energy electron collisions with tetrahydropyran

    NASA Astrophysics Data System (ADS)

    Barbosa, Alessandra Souza; Bettega, Márcio H. F.

    2016-02-01

    We report on calculated elastic cross sections for low-energy electron collisions with the cyclic ether tetrahydropyran (C5H10O). The calculations were carried out with the Schwinger multichannel method implemented with norm-conserving pseudopotentials in the static-exchange-polarization approximation for energies up to 20 eV. Our cross sections are compared with previous results obtained for cyclohexane and 1,4-dioxane, since the three molecules present similar structures. The calculated differential cross sections for these three molecules present similarities, except at low scattering angles, where the differential cross sections of tetrahydropyran present a sharp increase due to the permanent dipole moment of the molecule. The similarities observed in the cross sections reveal that the molecular geometry plays an important role in the description of scattering process. We also compared our calculated elastic integral cross section for tetrahydropyran with experimental total cross sections data available in the literature and found a good qualitative agreement between both results.

  10. Energy and Mass-Number Dependence of Hadron-Nucleus Total Reaction Cross Sections

    NASA Astrophysics Data System (ADS)

    Kohama, Akihisa; Iida, Kei; Oyamatsu, Kazuhiro

    2016-09-01

    We thoroughly investigate how proton-nucleus total reaction cross sections depend on the target mass number A and the proton incident energy. In doing so, we systematically analyze nuclear reaction data that are sensitive to nuclear size, namely, proton-nucleus total reaction cross sections and differential elastic cross sections, using a phenomenological black-sphere approximation of nuclei that we are developing. In this framework, the radius of the black sphere is found to be a useful length scale that simultaneously accounts for the observed proton-nucleus total reaction cross section and first diffraction peak in the proton elastic differential cross section. This framework, which is shown here to be applicable to antiprotons, is expected to be applicable to any kind of projectile that is strongly attenuated in the nucleus. On the basis of a cross-section formula constructed within this framework, we find that a less familiar A1/6 dependence plays a crucial role in describing the energy dependence of proton-nucleus total reaction cross sections.

  11. Energy-dependent excitation cross section measurements of the diagnostic lines of Fe XVII.

    PubMed

    Brown, G V; Beiersdorfer, P; Chen, H; Scofield, J H; Boyce, K R; Kelley, R L; Kilbourne, C A; Porter, F S; Gu, M F; Kahn, S M; Szymkowiak, A E

    2006-06-30

    By implementing a large-area, gain-stabilized microcalorimeter array on an electron beam ion trap, the electron-impact excitation cross sections for the dominant x-ray lines in the Fe XVII spectrum have been measured as a function of electron energy establishing a benchmark for atomic calculations. The results show that the calculations consistently predict the cross section of the resonance line to be significantly larger than measured. The lower cross section accounts for several problems found when modeling solar and astrophysical Fe XVII spectra. PMID:16907303

  12. Validation Analyses of IEAF-2001 Activation Cross-Section Data for SS-316 and F82H Steels Irradiated in a White d-Li Neutron Field

    NASA Astrophysics Data System (ADS)

    Simakov, S. P.; Fischer, U.; v. Möllendorff, U.; Schmuck, I.; Tsige-Tamirat, H.; Wilson, P. P. H.

    2005-05-01

    The evaluated intermediate-energy activation cross-section library IEAF-2001 has been tested against integral experiments with SS-316 and F82H steels exposed to a white neutron flux spectrum extending up to 55 MeV. By making use of the ALARA inventory code the expected γ-active product nuclide inventories were calculated and compared with the measured one. It was found that IEAF-2001 reasonably agrees with experimental data for most of the detected radioisotopes. The reasons for some larger disagreements were found to be the uncertainty of the sample elemental composition, non-validated neutron activation reaction cross sections, and sequential charge particle reactions.

  13. Au, Bi, Co and Nb cross-section measured by quasimonoenergetic neutrons from p + 7Li reaction in the energy range of 18-36 MeV

    NASA Astrophysics Data System (ADS)

    Majerle, M.; Bém, P.; Novák, J.; Šimečková, E.; Štefánik, M.

    2016-09-01

    Au, Bi, Co and Nb samples were irradiated several times with quasi-monoenergetic neutrons from p + 7Li reaction in the energy range of 18-36 MeV. The activities of the samples were measured with the HPGe detector and the reaction rates were calculated. The cross-sections were extracted using the SAND-II method with the reference cross-sections from the EAF-2010 database. The uncertainties of the final results are discussed.

  14. Effects of nuclear cross sections at different energies on the radiation hazard from galactic cosmic rays.

    PubMed

    Lin, Z W; Adams, J H

    2007-03-01

    The radiation hazard for astronauts from galactic cosmic rays (GCR) is a major obstacle to long-duration human space exploration. Space radiation transport codes have been developed to calculate the radiation environment on missions to the Moon, Mars, and beyond. We have studied how uncertainties in fragmentation cross sections at different energies affect the accuracy of predictions from such radiation transport calculations. We find that, in deep space, cross sections at energies between 0.3 and 0.85 GeV/nucleon have the largest effect in solar maximum GCR environments. At the International Space Station, cross sections at higher energies have the largest effect due to the geomagnetic cutoff. PMID:17316078

  15. Rotational Energy Transfer Cross Sections in N2-N2 Collisions

    NASA Technical Reports Server (NTRS)

    Huo, Winifred M.; Green, Sheldon; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    Rotational inelastic transitions of N2 have been studied in the coupled state (CS, also called centrifugal sudden) and infinite-order-sudden (IOS) approximations, using the N2-N2 rigid-rotor potential of van der Avoird et al. For benchmarking purposes, close coupling (CC) calculations have also been carried out over a limited energy range and for even j - even j collisions only. Both the CC and CS cross sections have been obtained with and without exchange symmetry, whereas exchange is neglected in the IOS calculations. The CS results track the CC cross sections rather well. At total energies between 113 to 219 cm(exp -1) the average deviation is 14%. The deviation decrease with increasing energy, indicating that the CS approximation can be used as a substitute at higher energies when the CC calculations become impractical. Comparison between the CS and IOS cross sections at the high energy end of the CS calculation, 500 - 680 cm(exp-1), shows significant differences between the two. In addition, the IOS results exhibits sensitivity to the amount of inelasticity and the results for large DELTA J transitions are subjected to bigger errors. At total energy 113 cm(exp -1) and above, the average deviation between state-to-state cross sections calculated with even and odd exchange symmetries is 1.5%.

  16. Energy-absorption capability and scalability of square cross section composite tube specimens

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.

    1987-01-01

    Static crushing tests were conducted on graphite/epoxy and Kevlar/epoxy square cross section tubes to study the influence of specimen geometry on the energy-absorption capability and scalability of composite materials. The tube inside width-to-wall thickness (W/t) ratio was determined to significantly affect the energy-absorption capability of composite materials. As W/t ratio decreases, the energy-absorption capability increases nonlinearly. The energy-absorption capability of Kevlar epoxy tubes was found to be geometrically scalable, but the energy-absorption capability of graphite/epoxy tubes was not geometrically scalable.

  17. Energy-absorption capability and scalability of square cross section composite tube specimens

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.

    1989-01-01

    Static crushing tests were conducted on graphite/epoxy and Kevlar/epoxy square cross section tubes to study the influence of specimen geometry on the energy-absorption capability and scalability of composite materials. The tube inside width-to-wall thickness (W/t) ratio was determined to significantly affect the energy-absorption capability of composite materials. As W/t ratio decreases, the energy-absorption capability increases nonlinearly. The energy-absorption capability of Kevlar epoxy tubes was found to be geometrically scalable, but the energy-absorption capability of graphite/epoxy tubes was not geometrically scalable.

  18. Endpoint behavior of high-energy scattering cross sections

    SciTech Connect

    Chay, Junegone; Kim, Chul

    2010-11-01

    In high-energy processes near the endpoint, there emerge new contributions associated with spectator interactions. Away from the endpoint region, these new contributions are suppressed compared to the leading contribution, but the leading contribution becomes suppressed as we approach the endpoint and the new contributions become comparable. We present how the new contributions scale as we reach the endpoint and show that they are comparable to the suppressed leading contributions in deep inelastic scattering by employing a power-counting analysis. The hadronic tensor in deep inelastic scattering is shown to factorize including the spectator interactions, and it can be expressed in terms of the light cone distribution amplitudes of initial hadrons. We also consider the contribution of the spectator contributions in Drell-Yan processes. Here the spectator interactions are suppressed compared to double parton annihilation according to the power counting.

  19. Energy deposition model based on electron scattering cross section data from water molecules

    NASA Astrophysics Data System (ADS)

    Muñoz, A.; Oiler, J. C.; Blanco, F.; Gorfinkiel, J. D.; Limão-Vieira, P.; Maira-Vidal, A.; Borge, M. J. G.; Tengblad, O.; Huerga, C.; Téllez, M.; García, G.

    2008-10-01

    A complete set of electrons scattering cross sections by water molecules over a broad energy range, from the me V to the Me V ranges, is presented in this study. These data have been obtained by combining experiments and calculations and cover most relevant processes, both elastic and inelastic, which can take place in the considered energy range. A new Monte Carlo simulation programme has been developed using as input parameter these cross sectional data as well as experimental energy loss spectra. The simulation procedure has been applied to obtain electron tracks and energy deposition plots in water when irradiated by a Ru-106 plaque as those used for brachyteraphy of ocular tumours. Finally, the low energy electron tracks provided by the present model have been compared with those obtained with other codes available in the literature

  20. Comparative study of the neutrino-nucleon cross section at ultrahigh energies

    SciTech Connect

    Goncalves, V. P.; Hepp, P.

    2011-01-01

    The high-energy neutrino cross section is a crucial ingredient in the calculation of the event rate in high-energy neutrino telescopes. Currently, there are several approaches that predict different behaviors for its magnitude for ultrahigh energies. In this paper, we present a comparison between the predictions based on linear Dokshitzer-Gribov-Lipatov-Altarelli-Parisi dynamics, nonlinear QCD, and the imposition of a Froissart-like behavior at high energies. In particular, we update the predictions based on the color glass condensate, presenting for the first time the results for {sigma}{sub {nu}N} using the solution of the running coupling Balitsky-Kovchegov equation. Our results demonstrate that the current theoretical uncertainty for the neutrino-nucleon cross section reaches a factor of three for neutrino energies around 10{sup 11} GeV and increases to a factor of five for 10{sup 13} GeV.

  1. Sensitivity of Activation Cross Sections of Tungsten to Nuclear Reaction Mechanisms

    SciTech Connect

    Avrigeanu, V.; Forrest, R.A.; Koning, A.J.

    2005-05-24

    In order to reduce the deviation of calculated-to-experimental activity (C/E) following benchmark experiments with pure W irradiated by 14-MeV neutrons, of interest for safety aspects and waste management of power plants, a detailed analysis of the activation cross sections was carried out using the computer codes EMPIRE-II and TALYS as well as local parameter sets within the STAPRE-H code. The sensitivity of the calculated cross sections to various model parameters is derived and discussed in connection with improving the C/E of the benchmark experiment.

  2. Pion and Kaon Lab Frame Differential Cross Sections for Intermediate Energy Nucleus-Nucleus Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Blattnig, Steve R.

    2008-01-01

    Space radiation transport codes require accurate models for hadron production in intermediate energy nucleus-nucleus collisions. Codes require cross sections to be written in terms of lab frame variables and it is important to be able to verify models against experimental data in the lab frame. Several models are compared to lab frame data. It is found that models based on algebraic parameterizations are unable to describe intermediate energy differential cross section data. However, simple thermal model parameterizations, when appropriately transformed from the center of momentum to the lab frame, are able to account for the data.

  3. Au photofission cross section by quasimonochromatic photons in the intermediate energy region

    SciTech Connect

    Lucherini, V.; Guaraldo, C.; De Sanctis, E.; Sandri, P.L.; Polli, E.; Reolon, A.R.; Iljinov, A.S.; Lo Nigro, S.; Aiello, S.; Bellini, V.; and others

    1989-03-01

    The photofission cross section of Au was determined in the energy range 100--300 MeV by means of a quasimonochromatic photon beam. The nuclear fissility P/sub f/ was calculated using the recently measured total photoabsorption cross sections. The nuclear excitation energy E/sup */, charge and mass of compound nucleus were obtained by means of an intranuclear cascade Monte Carlo calculation. The fissility values determined for Au, Bi, and U were compared with the predictions of the cascade-evaporation model and remarkably fitted by the calculation.

  4. Cross sections for one-neutron knock-out from 37Ca at intermediate energy

    NASA Astrophysics Data System (ADS)

    Bürger, A.; Azaiez, F.; Algora, A.; Al-Khatib, A.; Bastin, B.; Benzoni, G.; Borcea, R.; Bourgeois, C.; Bringel, P.; Clément, E.; Dalouzy, J.-C.; Dlouhý, Z.; Dombrádi, Z.; Drouart, A.; Engelhardt, C.; Franchoo, S.; Fülöp, Z.; Görgen, A.; Grévy, S.; Hübel, H.; Ibrahim, F.; Korten, W.; Mrázek, J.; Navin, A.; Rotaru, F.; Roussel Chomaz, P.; Saint-Laurent, M.-G.; Sletten, G.; Sohler, D.; Sorlin, O.; Stanoiu, M.; Stefan, I.; Theisen, C.; Timis, C.; Verney, D.; Williams, S.

    2012-12-01

    The cross section for the knock-out of a deeply bound valence neutron from 37Ca at an incident beam energy of 60AMeV has been measured along with momentum distributions of the residual nuclei and γ rays from the de-excitation of the first excited state in 36Ca. As for other cases of deeply bound nucleons studied using knock-out reactions, the reduction of the measured cross section compared to theoretical predictions is stronger than those observed for near-magic stable nuclei. Both the momentum distributions and the excitation energy of the first excited state in 36Ca indicate a sizable N=16 gap.

  5. On the Cross-Energy Cross-Pitch-Angle Coherence of Electrons in the Outer Radiation Belt

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Reeves, G. D.; Tu, W.; Cunningham, G.; Henderson, M. G.; Kletzing, C.; Redmon, R. J.

    2014-12-01

    Relativistic electrons, mainly trapped in the Earth's outer radiation belt, present a highly hazardous radiation environment for electronic hardware on board satellites and spacecraft. Thus developing a predictive capability for MeV electron levels as well as understanding the physics have been deemed critical for both space research and industry communities. In this work, we first demonstrate that a high cross-energy cross-pitch-angle coherence exists between the trapped ~MeV electrons and precipitating ~100s KeV electrons—observed respectively by Van Allen Probes and NOAA POES satellites in different orbits—by conducting a correlation survey on measurements from both high- and low-altitudes. Then, based upon the results, we further test the possibility of using a linear prediction filter model, driven by POES observations from low-Earth-orbits, to predict the energization of MeV electrons after geomagnetic storms, as well as the evolving distributions of MeV electrons in real time. Finally, to account for this high coherence, we provide our hypothesis based upon theoretical calculations and numerical simulations for individual events using diffusion codes with realistic particle and wave inputs from missions including Van Allen Probes. Results from this study unveil new knowledge on radiation belt dynamics, add new science significance to a long existing space infrastructure, and provide practical and useful tools to the whole space community.

  6. Active faults crossing trunk pipeline routes: some important steps to avoid disaster

    NASA Astrophysics Data System (ADS)

    Besstrashnov, V. M.; Strom, A. L.

    2011-05-01

    Assessment of seismic strong motion hazard produced by earthquakes originating within causative fault zones allows rather low accuracy of localisation of these structures that can be provided by indirect evidence of fault activity. In contrast, the relevant accuracy of localisation and characterisation of active faults, capable of surface rupturing, can be achieved solely by the use of direct evidence of fault activity. This differentiation requires strict definition of what can be classified as "active fault" and the normalisation of methods used for identification and localisation of active faults crossing oil and natural gas trunk pipelines.

  7. Cross-language Activation and the Phonetics of Code-switching

    NASA Astrophysics Data System (ADS)

    Piccinini, Page Elizabeth

    It is now well established that bilinguals have both languages activated to some degree at all times. This cross-language activation has been documented in several research paradigms, including picture naming, reading, and electrophysiological studies. What is less well understood is how the degree a language is activated can vary in different language environments or contexts. Furthermore, when investigating effects of order of acquisition and language dominance, past research has been mixed, as the two variables are often conflated. In this dissertation, I test how degree of cross-language activation can vary according to context by examining phonetic productions in code-switching speech. Both spontaneous speech and scripted speech are analyzed. Follow-up perception experiments are conducted to see if listeners are able to anticipate language switches, potentially due to the phonetic cues in the signal. Additionally, by focusing on early bilinguals who are L1 Spanish but English dominant, I am able to see what plays a greater role in cross-language activation, order of acquisition or language dominance. I find that speakers do have intermediate phonetic productions in code-switching contexts relative to monolingual contexts. Effects are larger and more consistent in English than Spanish. Similar effects are found in speech perception. Listeners are able to anticipate language switches from English to Spanish but not Spanish to English. Together these results suggest that language dominance is a more important factor than order of acquisition in cross-language activation for early bilinguals. Future models on bilingual language organization and access should take into account both context and language dominance when modeling degrees of cross-language activation.

  8. Total reaction cross sections in CEM and MCNP6 at intermediate energies

    DOE PAGESBeta

    Kerby, Leslie M.; Mashnik, Stepan G.

    2015-05-14

    Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region (50 MeV to 5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used inmore » the preequilibrium and evaporation stages of CEM are based on the Dostrovsky et al. model, published in 1959. Better cross section models are now available. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results.« less

  9. Total reaction cross sections in CEM and MCNP6 at intermediate energies

    NASA Astrophysics Data System (ADS)

    Kerby, Leslie M.; Mashnik, Stepan G.

    2015-08-01

    Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region (∼ 50 MeV to ∼ 5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used in the preequilibrium and evaporation stages of CEM are based on the Dostrovsky et al. model, published in 1959. Better cross section models are available now. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results. Our current results indicate this is, in fact, the case.

  10. Average Neutron Total Cross Sections in the Unresolved Energy Range From ORELA High Resolutio Transmission Measurements

    SciTech Connect

    Derrien, H

    2004-05-27

    Average values of the neutron total cross sections of {sup 233}U, {sup 235}U, {sup 238}U, and {sup 239}Pu have been obtained in the unresolved resonance energy range from high-resolution transmission measurements performed at ORELA in the past two decades. The cross sections were generated by correcting the effective total cross sections for the self-shielding effects due to the resonance structure of the data. The self-shielding factors were found by calculating the effective and true cross sections with the computer code SAMMY for the same Doppler and resolution conditions as for the transmission measurements, using an appropriate set of resonance parameters. Our results are compared to results of previous measurements and to the current ENDF/B-VI data.

  11. Measurements of Deuteron-Induced Activation Cross Sections for IFMIF Accelerator Structural Materials

    SciTech Connect

    Nakao, Makoto; Hori, Jun-ichi; Ochiai, Kentaro; Sato, Satoshi; Yamauchi, Michinori; Nishitani, Takeo; Ishioka, Noriko S.

    2005-05-24

    Activation cross sections for deuteron-induced reactions on aluminum, copper, and tungsten were measured by using a stacked-foil method. The stacked foils were irradiated with deuteron beam at the AVF cyclotron in the TIARA facility, JAERI. We obtained the activation cross sections for 27Al(d,2p)27Mg, 27Al(d,x)24Na, natCu(d,x)62,63Zn, 61,64Cu, and natW(d,x)181-184,186Re, 187W in the 22-40 MeV region. These cross sections were compared with other experimental ones and the data in the ACSELAM library calculated by the ALICE-F code.

  12. STAT2 Is Required for TLR-Induced Murine Dendritic Cell Activation and Cross-Presentation.

    PubMed

    Xu, Jun; Lee, Michael H; Chakhtoura, Marita; Green, Benjamin L; Kotredes, Kevin P; Chain, Robert W; Sriram, Uma; Gamero, Ana M; Gallucci, Stefania

    2016-07-01

    TLR-stimulated cross-presentation by conventional dendritic cells (cDCs) is important in host defense and antitumor immunity. We recently reported that cDCs lacking the type I IFN signaling molecule STAT2 are impaired in cross-presenting tumor Ags to CD8(+) T cells. To investigate how STAT2 affects cross-presentation, we determined its requirements for dendritic cell activation. In this study, we report that STAT2 is essential for the activation of murine female cDCs upon TLR3, -4, -7, and -9 stimulation. In response to various TLR ligands, Stat2(-/-) cDCs displayed reduced expression of costimulatory molecules and type I IFN-stimulated genes. The cDC responses to exogenous IFN-α that we evaluated required STAT2 activation, indicating that the canonical STAT1-STAT2 heterodimers are the primary signaling transducers of type I IFNs in cDCs. Interestingly, LPS-induced production of IL-12 was STAT2 and type I IFN receptor (IFNAR) dependent, whereas LPS-induced production of TNF-α and IL-6 was STAT2 and IFNAR independent, suggesting a specific role of the IFNAR-STAT2 axis in the stimulation of proinflammatory cytokines by LPS in cDCs. In contrast, R848- and CpG-induced cytokine production was less influenced by the IFNAR-STAT2 axis. Short kinetics and IFNAR blockade studies showed that STAT2 main function is to transduce signals triggered by autocrine type I IFNs. Importantly, Stat2(-/-) cDCs were deficient in cross-presenting to CD8(+) T cells in vitro upon IFN-α, CpG, and LPS stimulation, and also in cross-priming and licensing cytotoxic T cell killers in vivo. We conclude that STAT2 plays a critical role in TLR-induced dendritic cell activation and cross-presentation, and thus is vital in host defense. PMID:27233962

  13. Cross section for production of low-energy electron-positron pairs by relativistic heavy ions

    NASA Technical Reports Server (NTRS)

    Eby, P. B.

    1991-01-01

    Starting with the lowest-order unscreened QED matrix element for electron-positron pair production by heavy charged particles, the paper calculates the cross section for this process differential in all independent variables and valid for all pair energies small compared to the incident particle energy. Integration over the possible emission angles of one of the pair members gives an expression that is valid for low-energy pairs that can be compared with previous work based on the Weizsaecker-Williams method. Integration over the possible angles of the other pair member then yields an expression identical to one derived by Racah. The high energy-transfer limit of the expression for the cross section integrated over electron and positron angles is found to be identical to that of Kelner in the unscreened case.

  14. Cross sections for elastic electron scattering by tetramethylsilane in the intermediate-energy range

    SciTech Connect

    Sugohara, R. T.; Lee, M.-T.; Iga, I.; Souza, G. L. C. de; Homem, M. G. P.

    2011-12-15

    Organosilicon compounds are of current interest due to the numerous applications of these species in industries. Some of these applications require the knowledge of electron collision cross sections, which are scarce for such compounds. In this work, we report absolute values of differential, integral, and momentum-transfer cross sections for elastic electron scattering by tetramethylsilane (TMS) measured in the 100-1000 eV energy range. The relative-flow technique is used to normalize our data. In addition, the independent-atom-model (IAM) and the additivity rule (AR), widely used to model electron collisions with light hydrocarbons, are also applied for e{sup -}-TMS interaction. The comparison of our measured results of cross sections and the calculated data shows good agreement, particularly near the higher-end of incident energies.

  15. Crossing statistic: Bayesian interpretation, model selection and resolving dark energy parametrization problem

    SciTech Connect

    Shafieloo, Arman

    2012-05-01

    By introducing Crossing functions and hyper-parameters I show that the Bayesian interpretation of the Crossing Statistics [1] can be used trivially for the purpose of model selection among cosmological models. In this approach to falsify a cosmological model there is no need to compare it with other models or assume any particular form of parametrization for the cosmological quantities like luminosity distance, Hubble parameter or equation of state of dark energy. Instead, hyper-parameters of Crossing functions perform as discriminators between correct and wrong models. Using this approach one can falsify any assumed cosmological model without putting priors on the underlying actual model of the universe and its parameters, hence the issue of dark energy parametrization is resolved. It will be also shown that the sensitivity of the method to the intrinsic dispersion of the data is small that is another important characteristic of the method in testing cosmological models dealing with data with high uncertainties.

  16. Photofission and total photoabsorption cross sections in the energy range of shadowing effects

    SciTech Connect

    Deppman, A.; Silva, G.; Anefalos, S.; Hisamoto, F.H.; Duarte, S.B.; Tavares, O.A.P.

    2006-06-15

    The energy dependence of photofission cross section for heavy nuclei has recently been well described in terms of a Monte Carlo calculation at energies from the pion photoproduction threshold up to 1 GeV [see, for instance, A. Deppman et al., Phys. Rev. Lett. 87 (2001) 182701]. Recent experimental data from CLAS (CEBAF Large Angle Spectrometer) collaboration have extended the measured photofission cross section up to 3.5 GeV for actinide and preactinide nuclei. In this work we address the calculation of photoabsorption and photofission cross sections for actinide and preactinide nuclei above 1 GeV, a region where the shadowing effect plays an important role in the nuclear photoabsorption process.

  17. Conservation Activities Related to Energy: Energy Activities for Urban Elementary Students, K-6.

    ERIC Educational Resources Information Center

    Schmidt, Joan S.; And Others

    Presented are simple activities, experiments, and demonstrations relating to energy conservation in the home. Activities are divided into four areas: (1) kitchen, (2) house, (3) transportation, and (4) heating and cooling. The material has been designed to require a minimum of preparation. Activity and game masters are provided. Activities may be…

  18. Cross-Language Activation in Children's Speech Production: Evidence from Second Language Learners, Bilinguals, and Trilinguals

    ERIC Educational Resources Information Center

    Poarch, Gregory J.; van Hell, Janet G.

    2012-01-01

    In five experiments, we examined cross-language activation during speech production in various groups of bilinguals and trilinguals who differed in nonnative language proficiency, language learning background, and age. In Experiments 1, 2, 3, and 5, German 5- to 8-year-old second language learners of English, German-English bilinguals,…

  19. Children's Preferences for Group Musical Activities in Child Care Centres: A Cross-Cultural Study

    ERIC Educational Resources Information Center

    Yim, Hoi Yin Bonnie; Ebbeck, Marjory

    2009-01-01

    This paper reports on a cross-cultural research study of children's preferences for group musical activities in child care centres. A total of 228 young children aged 4-5 years in seven child care centres in Hong Kong and in the Adelaide City of South Australia participated in the study. Both qualitative and quantitative data were collected via a…

  20. Power Perceptions and Negotiations in a Cross-National Email Writing Activity

    ERIC Educational Resources Information Center

    Liu, Yichun

    2011-01-01

    The present study investigates EFL students' perceptions of power differentials and their negotiation strategies when communicating with native English-speaking students via emails. The study involved 28 Taiwanese and American undergraduates who participated in a semester-long cross-national email writing activity. Findings show that students in…

  1. Acquisition of Compound Words in Chinese-English Bilingual Children: Decomposition and Cross-Language Activation

    ERIC Educational Resources Information Center

    Cheng, Chenxi; Wang, Min; Perfetti, Charles A.

    2011-01-01

    This study investigated compound processing and cross-language activation in a group of Chinese-English bilingual children, and they were divided into four groups based on the language proficiency levels in their two languages. A lexical decision task was designed using compound words in both languages. The compound words in one language contained…

  2. Students' Evaluation of Google Hangouts through a Cross-Cultural Group Discussion Activity

    ERIC Educational Resources Information Center

    Kobayashi, Michiko

    2015-01-01

    The study investigated perceived ease of use and usefulness of Google Hangouts as an instructional/learning tool. Forty-two teacher education students at U.S and Japanese universities participated in an online cross-cultural activity using Google Hangouts and discussed cultural differences between the two countries and their teaching philosophies.…

  3. Europe: Language Arts around the World, Volume I. Cross Curricular Activities for Grades 4-6.

    ERIC Educational Resources Information Center

    Fuchs, Lucy

    Suggesting that students in the intermediate grades can explore the world around them and practice valuable skills in spelling, reading, writing, communication, and language, this book presents cross-curricular units designed to integrate language-arts activities into the study of European cultures. The units in the book reach diverse needs by…

  4. 48 CFR 1852.228-76 - Cross-waiver of liability for space station activities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Cross-waiver of liability for space station activities. 1852.228-76 Section 1852.228-76 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

  5. 48 CFR 1852.228-76 - Cross-waiver of liability for space station activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Cross-waiver of liability for space station activities. 1852.228-76 Section 1852.228-76 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

  6. 48 CFR 1852.228-76 - Cross-waiver of liability for space station activities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Cross-waiver of liability for space station activities. 1852.228-76 Section 1852.228-76 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

  7. Solar Energy Education. Renewable energy activities for earth science

    SciTech Connect

    Not Available

    1980-01-01

    A teaching manual is provided to aid teachers in introducing renewable energy topics to earth science students. The main emphasis is placed on solar energy. Activities for the student include a study of the greenhouse effect, solar gain for home heating, measuring solar radiation, and the construction of a model solar still to obtain fresh water. Instructions for the construction of apparatus to demonstrate a solar still, the greenhouse effect and measurement of the altitude and azimuth of the sun are included. (BCS)

  8. Fibromodulin Interacts with Collagen Cross-linking Sites and Activates Lysyl Oxidase*

    PubMed Central

    Bihan, Dominique; Bonna, Arkadiusz; Rubin, Kristofer; Farndale, Richard W.

    2016-01-01

    The hallmark of fibrotic disorders is a highly cross-linked and dense collagen matrix, a property driven by the oxidative action of lysyl oxidase. Other fibrosis-associated proteins also contribute to the final collagen matrix properties, one of which is fibromodulin. Its interactions with collagen affect collagen cross-linking, packing, and fibril diameter. We investigated the possibility that a specific relationship exists between fibromodulin and lysyl oxidase, potentially imparting a specific collagen matrix phenotype. We mapped the fibromodulin-collagen interaction sites using the collagen II and III Toolkit peptide libraries. Fibromodulin interacted with the peptides containing the known collagen cross-linking sites and the MMP-1 cleavage site in collagens I and II. Interestingly, the interaction sites are closely aligned within the quarter-staggered collagen fibril, suggesting a multivalent interaction between fibromodulin and several collagen helices. Furthermore, we detected an interaction between fibromodulin and lysyl oxidase (a major collagen cross-linking enzyme) and mapped the interaction site to 12 N-terminal amino acids on fibromodulin. This interaction also increases the activity of lysyl oxidase. Together, the data suggest a fibromodulin-modulated collagen cross-linking mechanism where fibromodulin binds to a specific part of the collagen domain and also forms a complex with lysyl oxidase, targeting the enzyme toward specific cross-linking sites. PMID:26893379

  9. Cross Section Sensitivity and Uncertainty Analysis Including Secondary Neutron Energy and Angular Distributions.

    Energy Science and Technology Software Center (ESTSC)

    1991-03-12

    Version 00 SUSD calculates sensitivity coefficients for one- and two-dimensional transport problems. Variance and standard deviation of detector responses or design parameters can be obtained using cross-section covariance matrices. In neutron transport problems, this code can perform sensitivity-uncertainty analysis for secondary angular distribution (SAD) or secondary energy distribution (SED).

  10. Measuring Neutron-Proton Radiative Capture Cross-section at Low Energy

    NASA Astrophysics Data System (ADS)

    Yu, To Chin; Kovash, Michael; Matthews, June; Yang, Hongwei; Yang, Yunjie

    2015-10-01

    The experiment aims to fill in a gap in our data for the cross-section of neutron-proton radiative capture (p(n,d γ)) at energies below 500 keV. Current measurements in this energy range are scarce and inconsistent with theoretical predictions and with each other. A well-determined cross-section of the capture reaction in the low energy range is useful in nuclear physics due to its fundamental nature. The measurement is also of interest in cosmology. Big Bang Nucleosynthesis (BBN), the process by which light elements are formed in early universe, is very sensitive to the p(n,d γ) cross-section in the low energy range. The measurement enables us to put tighter constraints on the theoretical predictions of BBN. We have conducted preliminary measurements in the van de Graaff accelerator facility at the University of Kentucky. Our array of detectors consists of three plastic scintillators to serve as proton targets and deuteron detectors, and five BGO scintillators to detect γ-rays. The combination results in an over-determination of reaction kinematics that discriminates against scattering processes and other backgrounds. We have obtained some early results which show promise for the precise measurement of the p(n,d γ) cross-section.

  11. Estimation of neutron energy for first resonance from absorption cross section for thermal neutrons

    NASA Technical Reports Server (NTRS)

    Bogart, Donald

    1951-01-01

    Examination of published data for some 52 isotopes indicates that the neutron energy for which the first resonance occurs is related to the magnitude of the thermal absorption cross section. The empirical relation obtained is in qualitative agreement with the results of a simplified version of the resonance theory of the nucleus of Breit-Wigner.

  12. Analysis and Parametric Investigation of Active Open Cross Section Thin Wall Beams

    NASA Astrophysics Data System (ADS)

    Griffiths, James

    The static behaviour of active Open Cross Section Thin Wall Beams (OCSTWB) with embedded Active/Macro Fibre Composites (AFCs/MFCs) has been investigated for the purpose of advancing the fundamental theory needed in the development of advanced smart structures. An efficient code that can analyze active OCSTWB using analytical equations has been studied. Various beam examples have been investigated in order to verify this recently developed analytical active OCSTWB analysis tool. The cross sectional stiffness constants and induced force, moments and bimoment predicted by this analytical code have been compared with those predicted by the 2-D finite element beam cross section analysis codes called the Variational Asymptotic Beam Sectional (VABS) analysis and the University of Michigan VABS (UM/VABS). Good agreement was observed between the results obtained from the analytical tool and VABS. The calculated cross sectional stiffness constants and induced force/moments, the constitutive relation and the six intrinstic static equilibrium equations for OCSTWB were all used together in a first-order accurate forward difference scheme in order to determine the average twist and deflections along the beam span. In order to further verify the analytical code, the static behaviour of a number of beam examples was investigated using 3-D Finite Element Analysis (FEA). For a particular cross section, the rigid body twist and displacements were minimized with the displacements of all the nodes in the 3-D FEA model that compose the cross section. This was done for a number of cross sections along the beam span in order to recover the global beam twist and displacement profiles from the 3-D FEA results. The global twist and deflections predicted by the analytical code agreed closely with those predicted by UM/VABS and 3-D FEA. The study was completed by a parametric investigation to determine the boundary conditions and the composite ply lay-ups of the active and passive plies that

  13. Synthesis, Characterization, and Antibacterial Activity of Cross-Linked Chitosan-Glutaraldehyde

    PubMed Central

    Li, Bin; Shan, Chang-Lin; Zhou, Qing; Fang, Yuan; Wang, Yang-Li; Xu, Fei; Han, Li-Rong; Ibrahim, Muhammad; Guo, Long-Biao; Xie, Guan-Lin; Sun, Guo-Chang

    2013-01-01

    This present study deals with synthesis, characterization and antibacterial activity of cross-linked chitosan-glutaraldehyde. Results from this study indicated that cross-linked chitosan-glutaraldehyde markedly inhibited the growth of antibiotic-resistant Burkholderia cepacia complex regardless of bacterial species and incubation time while bacterial growth was unaffected by solid chitosan. Furthermore, high temperature treated cross-linked chitosan-glutaraldehyde showed strong antibacterial activity against the selected strain 0901 although the inhibitory effects varied with different temperatures. In addition, physical-chemical and structural characterization revealed that the cross-linking of chitosan with glutaraldehyde resulted in a rougher surface morphology, a characteristic Fourier transform infrared (FTIR) band at 1559 cm−1, a specific X-ray diffraction peak centered at 2θ = 15°, a lower contents of carbon, hydrogen and nitrogen, and a higher stability of glucose units compared to chitosan based on scanning electron microscopic observation, FTIR spectra, X-ray diffraction pattern, as well as elemental and thermo gravimetric analysis. Overall, this study indicated that cross-linked chitosan-glutaraldehyde is promising to be developed as a new antibacterial drug. PMID:23670533

  14. Fluoroethylenepropylene ferroelectret films with cross-tunnel structure for piezoelectric transducers and micro energy harvesters

    SciTech Connect

    Zhang, Xiaoqing; Sessler, Gerhard M.; Wang, Yujie

    2014-08-21

    Layered fluoroethylenepropylene (FEP) ferroelectret films with cross-tunnel structure were fabricated from sheets of FEP films by template-patterning followed by a fusion-bonding process and contact charging. The typical piezoelectric d{sub 33} coefficients, measured by a quasi-static method of samples not annealed, are in the range of 1000–3700 pC/N. The resonance behavior of the samples is analyzed by dielectric spectroscopy which also yields Young's modulus. Microphones built with such films exhibit a somewhat decreasing frequency response up to 1 kHz, an increase of the responses due to diffraction effects at higher frequencies, and eventually a peak probably due to a thickness resonance at about 40 kHz. Annealing at 125 °C indicates that the sensitivity stabilizes at about 40% of the original value. From this data, stable dynamic d{sub 33} coefficients of up to 300 pC/N can be calculated. A micro energy harvesting generator utilizing these films and based on the excitation of thickness vibrations is also described. With an active area of 4.3 cm{sup 2} and a seismic mass of 69.5 g, power up to 0.5 μW referred to an acceleration of 1 g can be generated at a frequency of 120 Hz.

  15. Fluoroethylenepropylene ferroelectret films with cross-tunnel structure for piezoelectric transducers and micro energy harvesters

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoqing; Sessler, Gerhard M.; Wang, Yujie

    2014-08-01

    Layered fluoroethylenepropylene (FEP) ferroelectret films with cross-tunnel structure were fabricated from sheets of FEP films by template-patterning followed by a fusion-bonding process and contact charging. The typical piezoelectric d33 coefficients, measured by a quasi-static method of samples not annealed, are in the range of 1000-3700 pC/N. The resonance behavior of the samples is analyzed by dielectric spectroscopy which also yields Young's modulus. Microphones built with such films exhibit a somewhat decreasing frequency response up to 1 kHz, an increase of the responses due to diffraction effects at higher frequencies, and eventually a peak probably due to a thickness resonance at about 40 kHz. Annealing at 125 °C indicates that the sensitivity stabilizes at about 40% of the original value. From this data, stable dynamic d33 coefficients of up to 300 pC/N can be calculated. A micro energy harvesting generator utilizing these films and based on the excitation of thickness vibrations is also described. With an active area of 4.3 cm2 and a seismic mass of 69.5 g, power up to 0.5 μW referred to an acceleration of 1 g can be generated at a frequency of 120 Hz.

  16. Reaction cross sections on carbon for neutron energies from 11. 5 to 19 MeV

    SciTech Connect

    Antolkovic, B. ); Dietze, G.; Klein, H. )

    1991-01-01

    This paper reports on neutron-induced reaction cross sections for carbon measured in the 11.5- to 19-MeV energy range. The response of an NE-213 scintillation detector is measured in steps of at least 0.5 MeV for monoenergetic neutrons, applying suitable time-of-flight techniques, and compared with Monte Carlo simulations. The total cross sections of all reactions with charged particles (except carbon recoil protons) in the exit channel are determined with respect to the n-p scattering cross section. In addition, the {sup 12}C(n,n{prime}3{alpha}) reaction is investigated for neutron energies of 11.9, 12.9, 14.0, 14.8, 17.0, and 19.0 MeV using the nuclear emulsion technique. As it is kinematically complete, this measurement yields the total and partial cross sections for the various channels of the {sup 12}C(n,n{prime}3{alpha}) reaction. The experimental data show deviations of up to {plus minus}25% from those recommended in ENDF/B-V, while a recent evaluation by Axton is partially confirmed. Reasonable agreement is found with most of the recent scattering experiments; thus, this data set represents a valuable constraint for further evaluations. The analysis performed, however, has shown that additional data from some partial reaction cross sections are needed.

  17. Enantioselective intermolecular cross Rauhut-Currier reactions of activated alkenes with acrolein.

    PubMed

    Zhou, Wei; Chen, Peng; Tao, Mengna; Su, Xiao; Zhao, Qingjie; Zhang, Junliang

    2016-06-18

    The enantioselective intermolecular cross Rauhut-Currier reaction of acrolein with active olefins has been a long-standing challenge because of the competitive MBH reaction and polymerization. Herein a highly enantioselective intermolecular cross Rauhut-Currier reaction of acrolein with 3-acyl acrylates and 2-ene-1,4-diones, which is enabled by newly designed Peng-Phos catalysts. This method is scalable and highly enantioselective (up to 96% ee). Several transformations of the R-C products are carried out to showcase the synthetic utility. PMID:27225510

  18. Cross-linking and modification of cytochrome c with redox-active metal complexes

    SciTech Connect

    Lukes, A.

    1991-05-02

    This thesis consists of two parts. The first part shows that a redox-active trinuclear metal cluster may be used as a cross-linking reagent for proteins. Electron transfer is observed in the protein oligomers. The second part involves labelling the cysteine residue of baker's yeast cytochrome c with chloromercuriferrocene. Chloromercuriferrocene reacts with cytochrome c in two interesting ways. Symmetrization produces two products; two proteins cross-linked with mercury and diferrocenylmercury. Simple substitution of FeHgCl onto the protein followed by the addition of a proton by electrophilic substitution affords ferrocene and the mercuric chloride modified protein. 16 refs., 3 figs.

  19. Optical coherence tomography for cross-sectional imaging of neural activity

    PubMed Central

    Yeh, Yi-Jou; Black, Adam J.; Landowne, David; Akkin, Taner

    2015-01-01

    Abstract. We report a functional optical coherence tomography cross-sectional scanner to detect neural activity using unmyelinated nerves dissected from squid. The nerves, unstained or stained with a voltage-sensitive dye, were imaged in a nerve chamber. Transient phase changes from backscattered light were detected during action potential propagation. The results show that the scanner can provide high spatiotemporal resolution cross-sectional images of neural activity (15  μs/A-line; 0.25  ms/B-scan; ∼8.5×5.5  μm2 in xz). The advantage of this method compared to monitoring a single depth profile z is a dramatic increase in the number of available sites that can be measured in two spatial dimensions xz with lateral scanning; therefore, the study demonstrates that two-dimensional monitoring of small-scale functional activity would also be feasible. PMID:26217674

  20. Raster image cross-correlation analysis for spatiotemporal visualization of intracellular degradation activities against exogenous DNAs

    PubMed Central

    Sasaki, Akira; Yamamoto, Johtaro; Jin, Takashi; Kinjo, Masataka

    2015-01-01

    Reducing intracellular DNA degradation is critical to enhance the efficiency of gene therapy. Exogenous DNA incorporation into cells is strictly blocked by the defense machinery of intracellular nuclease activity. Raster image correlation spectroscopy (RICS) and raster image cross-correlation spectroscopy (cross-correlation RICS; ccRICS) are image-based correlation methods. These powerful tools allow the study of spatiotemporal molecular dynamics. Here we performed spatiotemporal ccRICS analyses of fluorescent DNA and directly monitored the process of exogenous DNA degradation in living cell cytoplasm. Such direct monitors of DNA degradation allow us to determine the fate of the exogenous DNA in living cells. On comparing the process in living cells, our study shows that cytoplasmic nuclease activity differs between cell lines; therefore, we propose that the difference of nuclease activity in cytoplasm dictates a different resistance to exogenous DNA incorporation. New insight on efficient gene delivery can be provided with our study. PMID:26400011

  1. Activation of polymeric materials towards enzymatic postgrafting and cross-linking.

    PubMed

    Fatarella, E; Ciabatti, I; Cortez, J

    2012-10-10

    A methodology to activate inert polymeric materials to enzymatic functionalisation is described herein. Plasma irradiation can be used to graft compounds containing a moiety that is reactive towards an enzyme of interest. Subsequently, such enzyme can be used to either postgraft functional compounds or cross-link the polymeric materials. Argon plasma was utilised to graft 2-aminoethyl methacrylate onto cotton and wool fibres, introducing surface alkylamine groups to impart reactivity towards transglutaminase and tyrosinase. The efficiency of plasma grafting was verified by ATR-FTIR. Enzyme postgrafting of fluorescent peptides coupled with confocal microscopy was used to demonstrate transglutaminase activity towards cotton, a material typically inert to this enzyme. The grafting of alkylamines onto wool resulted in additional cross-linking by both enzymes, leading to significantly increased yarn breaking load and elongation at break. This technology permits the activation of inert materials towards enzymatic postgrafting, with applications in fields as diverse as textiles and biomaterials. PMID:22975121

  2. Raster image cross-correlation analysis for spatiotemporal visualization of intracellular degradation activities against exogenous DNAs.

    PubMed

    Sasaki, Akira; Yamamoto, Johtaro; Jin, Takashi; Kinjo, Masataka

    2015-01-01

    Reducing intracellular DNA degradation is critical to enhance the efficiency of gene therapy. Exogenous DNA incorporation into cells is strictly blocked by the defense machinery of intracellular nuclease activity. Raster image correlation spectroscopy (RICS) and raster image cross-correlation spectroscopy (cross-correlation RICS; ccRICS) are image-based correlation methods. These powerful tools allow the study of spatiotemporal molecular dynamics. Here we performed spatiotemporal ccRICS analyses of fluorescent DNA and directly monitored the process of exogenous DNA degradation in living cell cytoplasm. Such direct monitors of DNA degradation allow us to determine the fate of the exogenous DNA in living cells. On comparing the process in living cells, our study shows that cytoplasmic nuclease activity differs between cell lines; therefore, we propose that the difference of nuclease activity in cytoplasm dictates a different resistance to exogenous DNA incorporation. New insight on efficient gene delivery can be provided with our study. PMID:26400011

  3. Executive control modulates cross-language lexical activation during L2 reading: evidence from eye movements.

    PubMed

    Pivneva, Irina; Mercier, Julie; Titone, Debra

    2014-05-01

    Models of bilingual reading such as Bilingual Interactive Activation Plus (Dijkstra & van Heuven, 2002) do not predict a central role for domain-general executive control during bilingual reading, in contrast with bilingual models from other domains, such as production (e.g., the Inhibitory Control Model; Green, 1998). We thus investigated whether individual differences among bilinguals in domain-general executive control modulate cross-language activation during L2 sentence reading, over and above other factors such as L2 proficiency. Fifty French-English bilinguals read L2-English sentences while their eye movements were recorded, and they subsequently completed a battery of executive control and L2 proficiency tasks. High- and low-constraint sentences contained interlingual homographs (chat = "casual conversation" in English, "a cat" in French), cognates (piano in English and French), or L2-specific control words. The results showed that greater executive control among bilinguals but not L2 proficiency reduced cross-language activation in terms of interlingual homograph interference. In contrast, increased L2 proficiency but not executive control reduced cross-language activation in terms of cognate facilitation. These results suggest that models of bilingual reading must incorporate mechanisms by which domain-general executive control can alter the earliest stages of bilingual lexical activation. PMID:24446754

  4. Neutrino energy reconstruction and the shape of the charged current quasielastic-like total cross section

    NASA Astrophysics Data System (ADS)

    Nieves, J.; Sánchez, F.; Simo, I. Ruiz; Vacas, M. J. Vicente

    2012-06-01

    We show that because of the multinucleon mechanism effects, the algorithm used to reconstruct the neutrino energy is not adequate when dealing with quasielastic-like events, and a distortion of the total flux-unfolded cross-section shape is produced. This amounts to a redistribution of strength from high to low energies, which gives rise to a sizable excess (deficit) of low (high) energy neutrinos. This distortion of the shape leads to a good description of the MiniBooNE unfolded charged current quasielastic-like cross sections published by A. A. Aguilar-Arevalo [(MiniBooNE Collaboration), Phys. Rev. DPRVDAQ1550-7998 81, 092005 (2010)]10.1103/PhysRevD.81.092005. However, these changes in the shape are artifacts of the unfolding process that ignores multinucleon mechanisms.

  5. Application of cross-sectional time series modeling for the prediction of energy expenditure from heart rate and accelerometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate estimation of energy expenditure (EE) in children and adolescents is required for a better understanding of physiological, behavioral, and environmental factors affecting energy balance. Cross-sectional time series (CSTS) models, which account for correlation structure of repeated observati...

  6. ORELA measurements to meet fusion energy neutron cross section needs. [2 to 80 MeV

    SciTech Connect

    Larson, D C

    1980-01-01

    Major neutron cross section measurements made at the Oak Ridge Electron Linear Accelerator (ORELA) that are useful to the fusion energy program are reviewed. Cross sections for production of gamma rays with energies 0.3 < E/sub ..gamma../ < 10.5 MeV were measured as a function of neutron energy over the range 0.1 < E/sub n/ < 20.0 MeV for Li, C, N, O, F, Na, Mg, Al, Si, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Nb, Mo, Ag, Sn, Ta, W, Au, Pb, and Th. Neutron emission cross sections have been measured for /sup 7/Li, Al, Ti, Cu, and Nb for 1 < E/sub n/ < 20 MeV. Some results of recent neutron total cross section measurements from 2 to 80 MeV for eleven materials (C, O, Al, Si, Ca, Cr, Fe, Ni, Cu, Au, and Pb) of interest to the FMIT project are presented. Finally, future directions of the ORELA program are outlined. 4 figures, 3 tables.

  7. Neutron capture cross-section measurement for the 186W(n,gamma)187W reaction at 0.0536eV energy.

    PubMed

    Uddin, M S; Chowdhury, M H; Hossain, S M; Latif, Sk A; Hafiz, M A; Islam, M A; Zakaria, A K M; Azharul Islam, S M

    2008-09-01

    The thermal neutron-induced activation cross section for the (186)W(n,gamma)(187)W reaction was measured at 0.0536eV neutron energy using TRIGA Mark-II research reactor, Atomic Energy Research Establishment, Savar, Dhaka, Bangladesh. The (197)Au(n,gamma)(198)Au monitor reaction induced in a high-purity gold foil was used to determine the effective neutron beam intensity. The activities induced in sample and monitor foils were measured nondestructively by a high-resolution HPGe gamma-ray detector. The present experimental cross-section value is the first one at 0.0536eV. The obtained new cross section that amounts to 26.6+/-1.6b is 2% higher than the recently reported data in ENDF/B-VII and 5% lower than that of JENDL-3.3. PMID:18325774

  8. Cross sections for low-energy inelastic H+Li collisions

    SciTech Connect

    Belyaev, Andrey K.; Barklem, Paul S.

    2003-12-01

    We report calculations for the low-energy near-threshold inelastic collision cross sections between the Li(2s,2p,3s,3p)+H(1s) states. Results are obtained by solving the coupled-channel equations. Order-of-magnitude estimates for higher states have been made with the multichannel Landau-Zener model. Potentials and couplings from H. Croft et al [J. Phys. B 32, 81 (1999)] are employed. The calculated cross sections are much smaller than ones predicted by the classical Thomsom atom formula currently employed in astrophysics. This result is important for the interpretation of stellar spectra.

  9. Predictions for high energy neutrino cross-sections from the ZEUS global PDF fits

    NASA Astrophysics Data System (ADS)

    Cooper-Sarkar, Amanda; Sarkar, Subir

    2008-01-01

    We have updated predictions for high energy neutrino and antineutrino charged current cross-sections within the conventional DGLAP formalism of NLO QCD using a modern PDF fit to HERA data, which also accounts in a systematic way for PDF uncertainties deriving from both model uncertainties and from the experimental uncertainties of the input data sets. Furthermore the PDFs are determined using an improved treatment of heavy quark thresholds. A measurement of the neutrino cross-section outside these predictions would signal the need for extension of the conventional formalism as in BFKL resummation, or even gluon recombination effects as in the colour glass condensate model.

  10. Hardee County Energy Activities - Middle School Level.

    ERIC Educational Resources Information Center

    Allen, Rodney F., Ed.

    Described are over 70 activities designed to help students develop writing skills by examining energy issues. Intended for middle school students, the lessons were developed by Hardee County, Florida teachers. Learning strategies employed include class discussions, analogies, word puzzles, letter writing, sentence completions, vocabulary building…

  11. Solar Energy Project, Activities: Chemistry & Physics.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of chemistry and physics experiments. Each unit presents an introduction to the unit; objectives; required skills and knowledge; materials; method; questions; recommendations for further work; and a teacher information sheet.…

  12. Solar Energy Project, Activities: Junior High Science.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of the junior high science curriculum. Each unit presents an introduction; objectives; skills and knowledge needed; materials; methods; questions; recommendations for further work; and a teacher information sheet. The teacher…

  13. Solar Energy Project, Activities: Earth Science.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of earth science experiments. Each unit presents an introduction; objectives; skills and knowledge needed; materials; method; questions; recommendations for further study; and a teacher information sheet. The teacher…

  14. Energy Activities for Junior High Social Studies.

    ERIC Educational Resources Information Center

    Minnesota State Energy Agency, St. Paul.

    The document contains seven learning activities for junior high students on the energy situation. Objectives are to help students gain understanding and knowledge about the relationships between humans and their social and physical environments; solve problems and clarify issues; examine personal beliefs and values; and recognize the relationships…

  15. Conversion of energy in cross-sectional divergences under different conditions of inflow

    NASA Technical Reports Server (NTRS)

    Peters, H

    1934-01-01

    This investigation treats the conversion of energy in conically divergent channels with constant opening ratio and half included angle of from 2.6 to 90 degrees, the velocity distribution in the entrance section being varied from rectangular distribution to fully developed turbulence by changing the length of the approach. The energy conversion is not completed in the exit section of the diffuser; complete conversion requires a discharge length which depends upon the included angle and the velocity distribution in the entrance section. Lastly, a spiral fan was mounted in the extreme length and the effect of the spiral flow on the energy conversion in the cross-sectional divergence explored.

  16. Differential cross sections for electron-impact vibrational-excitation of tetrahydrofuran at intermediate impact energies

    SciTech Connect

    Do, T. P. T.; Lopes, M. C. A.; Konovalov, D. A.; White, R. D.; Brunger, M. J. E-mail: darryl.jones@flinders.edu.au; Jones, D. B. E-mail: darryl.jones@flinders.edu.au

    2015-03-28

    We report differential cross sections (DCSs) for electron-impact vibrational-excitation of tetrahydrofuran, at intermediate incident electron energies (15-50 eV) and over the 10°-90° scattered electron angular range. These measurements extend the available DCS data for vibrational excitation for this species, which have previously been obtained at lower incident electron energies (≤20 eV). Where possible, our data are compared to the earlier measurements in the overlapping energy ranges. Here, quite good agreement was generally observed where the measurements overlapped.

  17. NEUTRON CROSS SECTION COVARIANCES FROM THERMAL ENERGY TO 20 MeV.

    SciTech Connect

    ROCHMAN,D.; HERMAN, M.; OBLOZINSKY, P.; MUGHABGHAB, S.F.; PIGNI, M.; KAWANO, T.

    2007-04-27

    We describe new method for energy-energy covariance calculation from the thermal energy up to 20 MeV. It is based on three powerful basic components: (i) Atlas of Neutron Resonances in the resonance region; (ii) the nuclear reaction model code EMPIRE in the unresolved resonance and fast neutron regions, and (iii) the Bayesian code KALMAN for correlations and error propagation. Examples for cross section uncertainties and correlations on {sup 90}Zr and {sup 193}Ir illustrate this approach in the resonance and fast neutron regions.

  18. Activation energy of water structural transitions

    NASA Astrophysics Data System (ADS)

    Kholmanskiy, Alexander

    2015-06-01

    In this work, the nature of molecular motions that dominate in the thermodynamics of anomalies of liquid water properties in the range of 0-100 °C has been studied. Temperature dependencies of water properties have been approximated by exponential functions and the activation energies for water structure transitions have been evaluated. The activation energy values were compared with the energy spectra of characteristic vibrations and with those of cooperative molecular motion in the lattice-type structure of hydrogen bonds. It has been found that it is the reaction of hydrogen bond breaking that mainly limits the abnormal dynamics of water viscosity, self-diffusion, dielectric relaxation time and electric conductivity. It has been assumed that the thermodynamics of cooperative motion and resonance phenomena in water clusters form a basis for the differentiation mechanism of extrema points in temperature dependencies of water density, isobaric heat capacity, sound velocity, surface tension coefficient and compressibility.

  19. Cross-modal activation of auditory regions during visuo-spatial working memory in early deafness.

    PubMed

    Ding, Hao; Qin, Wen; Liang, Meng; Ming, Dong; Wan, Baikun; Li, Qiang; Yu, Chunshui

    2015-09-01

    Early deafness can reshape deprived auditory regions to enable the processing of signals from the remaining intact sensory modalities. Cross-modal activation has been observed in auditory regions during non-auditory tasks in early deaf subjects. In hearing subjects, visual working memory can evoke activation of the visual cortex, which further contributes to behavioural performance. In early deaf subjects, however, whether and how auditory regions participate in visual working memory remains unclear. We hypothesized that auditory regions may be involved in visual working memory processing and activation of auditory regions may contribute to the superior behavioural performance of early deaf subjects. In this study, 41 early deaf subjects (22 females and 19 males, age range: 20-26 years, age of onset of deafness < 2 years) and 40 age- and gender-matched hearing controls underwent functional magnetic resonance imaging during a visuo-spatial delayed recognition task that consisted of encoding, maintenance and recognition stages. The early deaf subjects exhibited faster reaction times on the spatial working memory task than did the hearing controls. Compared with hearing controls, deaf subjects exhibited increased activation in the superior temporal gyrus bilaterally during the recognition stage. This increased activation amplitude predicted faster and more accurate working memory performance in deaf subjects. Deaf subjects also had increased activation in the superior temporal gyrus bilaterally during the maintenance stage and in the right superior temporal gyrus during the encoding stage. These increased activation amplitude also predicted faster reaction times on the spatial working memory task in deaf subjects. These findings suggest that cross-modal plasticity occurs in auditory association areas in early deaf subjects. These areas are involved in visuo-spatial working memory. Furthermore, amplitudes of cross-modal activation during the maintenance stage were

  20. 89Y(γ,xn) reaction cross-section measurements with bremsstrahlung end-point energies of 50-65 MeV

    NASA Astrophysics Data System (ADS)

    Zaman, Muhammad; Kim, Guinyun; Kim, Kwangsoo; Shahid, Muhammad; Naik, Haladhara; Yang, Sungchul; Shin, Sung-Gyun; Cho, Moo-Hyun

    2015-10-01

    The cross-sections for 89Y(γ, n)88Y, 89Y(γ, 2n)87Y, 89Y(γ, 3n)86Y, and 89Y(γ, 4n)85Y reactions for the end-point bremsstrahlung energies of 50 and 65 MeV were determined by using an activation and an off-line γ-ray spectrometric techniques with the electron linear accelerator at the Pohang Accelerator laboratory (PAL), Korea. The photon-induced reaction cross-sections of 89Y as functions of the photon energy were taken from the TENDL-2013 nuclear data library based on the TALYS 1.6 program. For comparison with our experimental results, the flux-weighted average cross-sections for the existing experimental data with mono-energetic photons and the theoretical values from TENDL-2013 were obtained. The reaction cross-section values measured at different end-point bremsstrahlung energies from the present work and from literature are found to be in good agreement with the theoretical values. The 89Y(γ, xn, x = 1 - 4) reaction cross-sections were observed to increase sharply from their threshold values to certain energies, until the next reaction channel opens, after which it remained constant for a while until the next reaction channel opened. Then, it decrease slowly with increasing of end-point bremsstrahlung energy due to the opening of different reaction channels.

  1. Improving Cross-Cultural Training and Measurement of Cross-Cultural Learning. Volume I of the Report of Supplemental Activities.

    ERIC Educational Resources Information Center

    Center for Research and Education, Denver, CO.

    An in-depth study of the process of adaption among Peace Corps volunteers in Brazil and cross-cultural training methodology is presented in this volume, the first of two reports resulting from the project. Since ultimate aims of cross-cultural learning tend to be described in abstract terms, the fundamental issue had to do with specifying and…

  2. The Magnetic Free Energy in Active Regions

    NASA Technical Reports Server (NTRS)

    Metcalf, Thomas R.; Mickey, Donald L.; LaBonte, Barry J.

    2001-01-01

    The magnetic field permeating the solar atmosphere governs much of the structure, morphology, brightness, and dynamics observed on the Sun. The magnetic field, especially in active regions, is thought to provide the power for energetic events in the solar corona, such as solar flares and Coronal Mass Ejections (CME) and is believed to energize the hot coronal plasma seen in extreme ultraviolet or X-rays. The question remains what specific aspect of the magnetic flux governs the observed variability. To directly understand the role of the magnetic field in energizing the solar corona, it is necessary to measure the free magnetic energy available in active regions. The grant now expiring has demonstrated a new and valuable technique for observing the magnetic free energy in active regions as a function of time.

  3. Titanium spallation cross sections between 30 and 584 MeV and Ar-39 activities on the moon

    NASA Technical Reports Server (NTRS)

    Steinburnn, F.; Fireman, E. L.

    1974-01-01

    The production cross sections of Ar39 for Ti spallation at 45-, 319-, 433-, and 584-MeV proton energies were measured to be 0.37 + or - 0.09, 12.4 + or - 3.7, 9.1 + or - 2.7, and 17.8 + or - 6.2 mb, respectively. Normalized Ar39 production rates and activities are also derived for protons above 40 MeV and for three differential proton spectra of the type approximately E(- alpha). It is concluded that, even for samples of high-Ti content, Ti spallation by solar protons below 200-MeV energy does not contribute significantly to their Ar39 radioactivity.

  4. AHEAD: Integrated Activities in the High Energy Astrophysics Domain

    NASA Astrophysics Data System (ADS)

    Piro, Luigi; Natalucci, Lorenzo; Ahead Consortium

    2015-09-01

    AHEAD (Integrated Activities in the High Energy Astrophysics Domain) is a forthcoming project approved in the framework of the European Horizon 2020 program (Research Infrastructures for High Energy Astrophysics). The overall objective of AHEAD is to integrate national efforts in high-energy Astrophysics and to promote the domain at the European level, to keep its community at the cutting edge of science and technology and ensure that space observatories for high-energy astrophysics, with particular regard to Athena, are at the state of the art. AHEAD will integrate key research infrastructures for on-ground test and calibration of space-based sensors and electronics and promote their coordinated use. In parallel, the best facilities for data analysis of high-energy astrophysical observatories will be made available to the European community. The technological development will focus on the improvement of selected critical technologies, background modeling, cross calibration, and feasibility studies of space-based instrumentation for the benefit of future high energy missions like Athena, and the best exploitation of existing observatories. AHEAD will support the community via grants for collaborative studies, dissemination of results, and promotion of workshops. A strong public outreach package will ensure that the domain is well publicized at national, European and International level. Networking, joint research activities and access to infrastructures as devised in AHEAD, will serve to establish strong connections between institutes and industry to create the basis for a more rapid advancement of high-energy astrophysical science, space oriented instrumentation and cutting-edge sensor technology in Europe. This enables the development of new technologies and the associated growth of the European technology market with a dedicated technology innovation package, as well as the creation of a new generation of researchers.

  5. Helix-coil melting in rigor and activated cross-bridges of skeletal muscle.

    PubMed

    Harrington, W F; Ueno, H; Davis, J S

    1988-01-01

    The studies described in this paper focus on the structural stability of the S-2 segment of the myosin cross-bridge in rigor, relaxed and activated muscle. Enzyme-probe observations of myofibrils of rabbit psoas muscle in rigor reveal that the alpha-helical LMM/HMM hinge domain of S-2 undergoes substantial local melting near physiological temperatures when the S-2 portion of the cross-bridge is detached from the thick filament surface. This process is strongly suppressed under ionic conditions where the cross-bridge is bound to the filament backbone. Activation of glycerinated fiber bundles results in a dramatic increase (approximately 100 fold compared to rigor and relaxed fibers) in the rate of chymotryptic cleavage in the hinge domain consistent with an increase in local melting at several sites encompassing this region. Comparative plots of the apparent rate-constant for cleavage within the S-2 hinge and the isometric force generated by active fibers versus [MgATP] give similar profiles suggesting a close coupling between this conformational transition and contractile force. This interpretation appears to be in accord with recent laser T-jump experiments of rigor ("bridges up") and activated psoas muscle fibers which also suggest coupling between melting in S-2 and force generation. PMID:3044019

  6. Cross sections and barriers for nuclear fission induced by high-energy nucleons

    SciTech Connect

    Grudzevich, O. T.; Yavshits, S. G.

    2013-03-15

    The cross sections for the fission of {sup 232}Th, {sup 235,238}U, {sup 237}Np, and {sup 239}Pu target nuclei that was induced by 20- to 1000-MeV neutrons and protons were calculated. The respective calculations were based on the multiconfiguration-fission (MCFx) model, which was used to describe three basic stages of the interaction of high-energy nucleons with nuclei: direct processes (intranuclear cascade), equilibration of the emerging compound system, and the decay of the compound nucleus (statistical model). Fission barriers were calculated within the microscopic approach for isotopic chains formed by 15 to 20 nuclei of the required elements. The calculated fission cross sections were compared with available experimental data. It was shown that the input data set and the theoretical model used made it possible to predict satisfactorily cross section for nuclear fission induced by 20- to 1000-MeV nucleons.

  7. Activation cross sections of longer-lived radionuclides produced in germanium by alpha particle irradiation

    NASA Astrophysics Data System (ADS)

    Takács, S.; Takács, M. P.; Ditrói, F.; Aikawa, M.; Haba, H.; Komori, Y.

    2016-09-01

    The cross sections of alpha particles induced nuclear reactions on natural germanium were investigated by using the standard stacked foil target technique, the activation method and high resolution gamma spectrometry. Targets with thickness of about 1 μm were prepared from natural Ge by vacuum evaporation onto 25 μm thick polyimide (Kapton) backing foils. Stacks were composed of Kapton-Ge-Ge-Kapton sandwich target foils and additional titanium monitor foils with nominal thickness of 11 μm to monitor the beam parameters using the natTi(α,x)51Cr reaction. The irradiations were done with Eα = 20.7 and Eα = 51.25 MeV, Iα = 50 nA alpha particle beams for about 1 h. Direct or cumulative activation cross sections were determined for production of the 72,73,75Se, 71,72,74,76,78As, and 69Ge radionuclides. The obtained experimental cross sections were compared to the results of theoretical calculations taken from the TENDL data library based on the TALYS computer code. A comparison was made with available experimental data measured earlier. Thick target yields were deduced from the experimental cross sections and compared with the data published before.

  8. Intermediate energy cross sections for electron-impact vibrational-excitation of pyrimidine

    SciTech Connect

    Jones, D. B.; Ellis-Gibbings, L.; García, G.; Nixon, K. L.; Lopes, M. C. A.; Brunger, M. J.

    2015-09-07

    We report differential cross sections (DCSs) and integral cross sections (ICSs) for electron-impact vibrational-excitation of pyrimidine, at incident electron energies in the range 15–50 eV. The scattered electron angular range for the DCS measurements was 15°–90°. The measurements at the DCS-level are the first to be reported for vibrational-excitation in pyrimidine via electron impact, while for the ICS we extend the results from the only previous condensed-phase study [P. L. Levesque, M. Michaud, and L. Sanche, J. Chem. Phys. 122, 094701 (2005)], for electron energies ⩽12 eV, to higher energies. Interestingly, the trend in the magnitude of the lower energy condensed-phase ICSs is much smaller when compared to the corresponding gas phase results. As there is no evidence for the existence of any shape-resonances, in the available pyrimidine total cross sections [Baek et al., Phys. Rev. A 88, 032702 (2013); Fuss et al., ibid. 88, 042702 (2013)], between 10 and 20 eV, this mismatch in absolute magnitude between the condensed-phase and gas-phase ICSs might be indicative for collective-behaviour effects in the condensed-phase results.

  9. 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.

  10. 48 CFR 1852.228-78 - Cross-waiver of liability for science or space exploration activities unrelated to the...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Space Act agreement that contains the cross-waiver of liability provision authorized in 14 CFR 1266.104... for science or space exploration activities unrelated to the International Space Station. 1852.228-78... Cross-waiver of liability for science or space exploration activities unrelated to the...

  11. 48 CFR 1852.228-78 - Cross-waiver of liability for science or space exploration activities unrelated to the...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Space Act agreement that contains the cross-waiver of liability provision authorized in 14 CFR 1266.104... for science or space exploration activities unrelated to the International Space Station. 1852.228-78... Cross-waiver of liability for science or space exploration activities unrelated to the...

  12. Nucleon-induced fission cross sections of heavy nuclei in the intermediate energy region

    NASA Astrophysics Data System (ADS)

    Prokofiev, Alexander V.

    Fission is the most important nuclear reaction for society at large today due to its use in energy production. However, this has raised the problem of how to treat the long-lived radioactive waste from nuclear reactors. A radical solution would be to change the composition of the waste into stable or short-lived nuclides, which could be done through nuclear transmutation. Such a concept requires accelerator-driven systems to be designed, where those for transmutation are reactor hybrids. This thesis is a contribution to the knowledge base for developing transmutation systems, specifically with respect to the computational modeling of the underlying nuclear reactions, induced by the incident and secondary particles. Intermediate energy fission cross sections are one important type of such data. Moreover, they are essential for understanding the fission process itself and related nuclear interactions. The experimental part of this work was performed at the neutron beam facility of The Svedberg Laboratory in Uppsala. Fission cross sections of 238U, 209Bi, natPb, 208Pb, 197Au, natW, and 181Ta were measured for neutrons in the range En = 30-160 MeV using thin-film breakdown counters for the fission fragment detection. A model was developed for the determination of the efficiency of such detectors. A compilation of existing data on proton-induced fission cross sections for nuclei from 165Ho to 239Pu was performed. The results, which constitute the main body of information in this field, were added to the worldwide EXFOR database. The dependences of the cross sections on incident energy and target nucleus were studied, which resulted in systematics that make it possible to give estimates for unmeasured nuclides. Nucleon-induced fission cross sections were calculated using an extended version of the cascade exciton model. A comparison with the systematics and the experimental data obtained in the present work revealed significant discrepancies. A modification of the model

  13. Transcriptional cross-activation between toxin-antitoxin systems of Escherichia coli

    PubMed Central

    2013-01-01

    Background Bacterial toxin-antitoxin (TA) systems are formed by potent regulatory or suicide factors (toxins) and their short-lived inhibitors (antitoxins). Antitoxins are DNA-binding proteins and auto-repress transcription of TA operons. Transcription of multiple TA operons is activated in temporarily non-growing persister cells that can resist killing by antibiotics. Consequently, the antitoxin levels of persisters must have been dropped and toxins are released of inhibition. Results Here, we describe transcriptional cross-activation between different TA systems of Escherichia coli. We find that the chromosomal relBEF operon is activated in response to production of the toxins MazF, MqsR, HicA, and HipA. Expression of the RelE toxin in turn induces transcription of several TA operons. We show that induction of mazEF during amino acid starvation depends on relBE and does not occur in a relBEF deletion mutant. Induction of TA operons has been previously shown to depend on Lon protease which is activated by polyphospate accumulation. We show that transcriptional cross-activation occurs also in strains deficient for Lon, ClpP, and HslV proteases and polyphosphate kinase. Furthermore, we find that toxins cleave the TA mRNA in vivo, which is followed by degradation of the antitoxin-encoding fragments and selective accumulation of the toxin-encoding regions. We show that these accumulating fragments can be translated to produce more toxin. Conclusion Transcriptional activation followed by cleavage of the mRNA and disproportionate production of the toxin constitutes a possible positive feedback loop, which can fire other TA systems and cause bistable growth heterogeneity. Cross-interacting TA systems have a potential to form a complex network of mutually activating regulators in bacteria. PMID:23432955

  14. Active faults crossing trunk pipeline routes: some important steps to avoid the disaster

    NASA Astrophysics Data System (ADS)

    Besstrashnov, Vladimir; Strom, Alexander

    2010-05-01

    Trunk pipelines that pass through tectonically active areas connecting oil and gas reservoirs with terminals and refineries cross active faults that can produce large earthquakes. Besides strong motion affecting vast areas, these earthquakes are often associated with surface faulting that provides additional hazard to pipelines. To avoid significant economic losses and environmental pollution, pipelines should be designed to sustain both effects (shaking and direct rupturing) without pipe damage and spill. Special studies aimed to provide necessary input data for the designers should be performed in the course of engineering survey. However, our experience on conducting and review of such studies for several oil and gas trunk pipelines in Russia show urgent need of more strict definition of basic conceptions and approaches used for identification and localization of these potentially hazardous tectonic features. Identification of active faults (fault zones) considered as causative faults - sources of strong motion caused by seismic waves that affect dozens kilometers of pipeline route can be done by use of both direct and indirect evidence of Late Pleistocene - Holocene activity of faults and fault zones. Since strong motion parameters can be considered as constant within the near-field zone, which width in case of large earthquake is up to dozens kilometers, accuracy of active fault location is not so critical and ±1-2 km precision provided by use of indirect evidence is acceptable. In contrast, if one have to identify and characterize zones of potential surface rupturing that require special design of the endangered pipeline section, only direct evidence of such activity can provide reliable input data for crossing design with relevant accuracy of fault location, amount and direction of displacement. Only traces of surface faults displacing Late Pleistocene - Holocene sediments and/or geomorphic features are considered as direct evidence of fault activity. Just

  15. Energy Expenditure During Extravehicular Activity Through Apollo

    NASA Technical Reports Server (NTRS)

    Paul, Heather L.

    2011-01-01

    Monitoring crew health during manned space missions has always been an important factor to ensure that the astronauts can complete the missions successfully and within safe physiological limits. The necessity of real-time metabolic rate monitoring during extravehicular activities (EVAs) came into question during the Gemini missions, when the energy expenditure required to complete EVA tasks exceeded the life support capabilities for cooling and humidity control and crewmembers (CMs) ended the EVAs fatigued and overworked. This paper discusses the importance of real-time monitoring of metabolic rate during EVA, and provides a historical look at energy expenditure during EVA through the Apollo program.

  16. Energy Expenditure During Extravehicular Activity Through Apollo

    NASA Technical Reports Server (NTRS)

    Paul, Heather L.

    2012-01-01

    Monitoring crew health during manned space missions has always been an important factor to ensure that the astronauts can complete the missions successfully and within safe physiological limits. The necessity of real-time metabolic rate monitoring during extravehicular activities (EVAs) came into question during the Gemini missions, when the energy expenditure required to complete EVA tasks exceeded the life support capabilities for cooling and humidity control and, as a result, crew members ended the EVAs fatigued and overworked. This paper discusses the importance of real-time monitoring of metabolic rate during EVAs, and provides a historical look at energy expenditure during EVAs through the Apollo Program.

  17. Cross-Layer Cluster-Based Energy-Efficient Protocol for Wireless Sensor Networks

    PubMed Central

    Mammu, Aboobeker Sidhik Koyamparambil; Hernandez-Jayo, Unai; Sainz, Nekane; de la Iglesia, Idoia

    2015-01-01

    Recent developments in electronics and wireless communications have enabled the improvement of low-power and low-cost wireless sensors networks (WSNs). One of the most important challenges in WSNs is to increase the network lifetime due to the limited energy capacity of the network nodes. Another major challenge in WSNs is the hot spots that emerge as locations under heavy traffic load. Nodes in such areas quickly drain energy resources, leading to disconnection in network services. In such an environment, cross-layer cluster-based energy-efficient algorithms (CCBE) can prolong the network lifetime and energy efficiency. CCBE is based on clustering the nodes to different hexagonal structures. A hexagonal cluster consists of cluster members (CMs) and a cluster head (CH). The CHs are selected from the CMs based on nodes near the optimal CH distance and the residual energy of the nodes. Additionally, the optimal CH distance that links to optimal energy consumption is derived. To balance the energy consumption and the traffic load in the network, the CHs are rotated among all CMs. In WSNs, energy is mostly consumed during transmission and reception. Transmission collisions can further decrease the energy efficiency. These collisions can be avoided by using a contention-free protocol during the transmission period. Additionally, the CH allocates slots to the CMs based on their residual energy to increase sleep time. Furthermore, the energy consumption of CH can be further reduced by data aggregation. In this paper, we propose a data aggregation level based on the residual energy of CH and a cost-aware decision scheme for the fusion of data. Performance results show that the CCBE scheme performs better in terms of network lifetime, energy consumption and throughput compared to low-energy adaptive clustering hierarchy (LEACH) and hybrid energy-efficient distributed clustering (HEED). PMID:25860073

  18. Energy-dependent excitation cross section measurements of the diagnostic lines of Fe XVII

    SciTech Connect

    Brown, G V; Beiersdorfer, P; Chen, H; Scofield, J H; Boyce, K R; Kelley, R L; Kilbourne, C A; Porter, F S; Kahn, S M; Szymkowiak, A E

    2005-01-24

    By implementing a large-area, gain-stabilized microcalorimeter array on an electron beam ion trap, the electron-impact excitation cross sections for the dominant x-ray lines in the Fe XVII spectrum have been measured as a function of electron energy up to greater than three times the threshold energy, establishing a benchmark for atomic calculations. The results reveal a consistent overestimation by recent calculations of the excitation cross section of the resonance transition, which is shown to be at the root of several long-standing problems associated with modeling solar and astrophysical Fe XVII spectra. The data do not show strong contributions from resonance excitation contrary to recent statements in the literature.

  19. Neutrino cross sections and future observations of ultrahigh-energy cosmic rays.

    PubMed

    Kusenko, Alexander; Weiler, Thomas J

    2002-04-22

    We show that future detectors of ultrahigh-energy cosmic-ray neutrinos will be able to measure neutrino-nucleon cross section, sigma(nu N), at energies as high as 10(11) GeV or higher. We find that the flux of upgoing charged leptons per unit surface area produced by neutrino interactions below the surface is inversely proportional to sigma(nu N). This contrasts with the rate of horizontal air showers (HAS) due to neutrino interactions in the atmosphere, which is proportional to sigma(nu N). Thus, by comparing the HAS and upgoing air shower rates, the neutrino-nucleon cross section can be inferred. Taken together, upgoing and horizontal rates ensure a healthy total event rate, regardless of the value of sigma(nu N). PMID:11955222

  20. Comparative study of tip cross-sections for efficient galloping energy harvesting

    NASA Astrophysics Data System (ADS)

    Yang, Yaowen; Zhao, Liya; Tang, Lihua

    2013-02-01

    This letter presents a comparative study of different tip cross-sections for small scale wind energy harvesting based on galloping phenomenon. A prototype device is fabricated with a piezoelectric cantilever and a tip body with various cross-section profiles (square, rectangle, triangle, and D-shape) and tested in a wind tunnel. Experimental results demonstrate the superiority of the square-sectioned tip for the low cut-in wind speed of 2.5 m/s and the high peak power of 8.4 mW. An analytical model is established and verified by the experimental results. It is recommended that the square section should be used for small wind galloping energy harvesters.

  1. TeV strings and the neutrino-nucleon cross section at ultrahigh energies.

    PubMed

    Cornet, F; Illana, J I; Masip, M

    2001-05-01

    In scenarios with the fundamental unification scale at the TeV one expects string excitations of the standard model fields at accessible energies. We study the neutrino-nucleon cross section in these models. We show that duality of the scattering amplitude forces the existence of a tower of massive leptoquarks that mediate the process in the s channel. Using the narrow-width approximation we find a sum rule for the production rate of resonances with different spin at each mass level. We show that these contributions can increase substantially the standard model neutrino-nucleon cross section, although they seem insufficient to explain the cosmic ray events above the Greisen-Zatsepin-Kuz'min cutoff energy. PMID:11328143

  2. DFT studies on the directing group dependent arene-alkene cross-couplings: arene activation vs. alkene activation.

    PubMed

    Zhang, Lei; Fang, De-Cai

    2015-08-01

    Due to its green-chemistry advantages, the dehydrogenative Heck reaction (DHR) has experienced enormous growth over the past few decades. In this work, two competing reaction channels were comparatively studied for the Pd(OAc)2-catalyzed DHRs of arenes with alkenes, referred to herein as the arene activation mechanism and the alkene activation mechanism, respectively, which mainly differ in the involvement of the reactants in the C-H activation step. Our calculations reveal that the commonly accepted arene activation mechanism is plausible for the desired arene-alkene cross-coupling; in contrast, the alternative alkene activation mechanism is kinetically inaccessible for the desired cross-coupling, but it is feasible for the homo-coupling of alkenes. The nature of directing groups on reactants could mainly determine the dominance of the two competing reaction routes, and therefore, influence the experimental yields. A wide range of directing groups experimentally used are examined by the density functional theory (DFT) method in this work, providing theoretical guidance for screening compatible reactants. PMID:26108375

  3. MCNP Continuous-Energy Neutron Cross Section Libraries for Temperatures from 300 to 1365K.

    Energy Science and Technology Software Center (ESTSC)

    2001-04-19

    Version 00 UTXS is a project whereby continuous-energy cross section libraries in ACE format suitable for the MCNP code were generated using the NJOY94.105 processing code. Libraries for various materials were generated at typical operating temperatures of the US Pressurized Water Reactor (PWR), Boiling Water Reactor (BWR), and the Russian PWR (VVER) as well as libraries for other non-reactor applications such as nuclear medicine.

  4. Active Control by Conservation of Energy Concept

    NASA Technical Reports Server (NTRS)

    Maestrello, Lucio

    2000-01-01

    Three unrelated experiments are discussed; each was extremely sensitive to initial conditions. The initial conditions are the beginnings of the origins of the information that nonlinearity displays. Initial conditions make the phenomenon unstable and unpredictable. With the knowledge of the initial conditions, active control requires far less power than that present in the system response. The first experiment is on the control of shocks from an axisymmetric supersonic jet; the second, control of a nonlinear panel response forced by turbulent boundary layer and sound; the third, control of subharmonic and harmonics of a panel forced by sound. In all three experiments, control is achieved by redistribution of periodic energy response such that the energy is nearly preserved from a previous uncontrolled state. This type of active control improves the performance of the system being controlled.

  5. The performance of density functional approximations for the structures and relative energies of minimum energy crossing points

    NASA Astrophysics Data System (ADS)

    Abate, Bayileyegn A.; Peralta, Juan E.

    2013-12-01

    The structural parameters and relative energies of the minimum-energy crossing points (MECPs) of eight small molecules are calculated using five different representative density functional theory approximations as well as MP2, MP4, and CCSD(T) as a reference. Compared to high-level wavefunction methods, the main structural features of the MECPs of the systems included in this Letter are reproduced reasonably well by density functional approximations, in agreement with previous works. Our results show that when high-level wavefunction methods are computationally prohibitive, density functional approximations offer a good alternative for locating and characterizing the MECP in spin-forbidden chemical reactions.

  6. Get Current: Switch on Clean Energy Activity Book

    SciTech Connect

    2014-06-01

    Switching on clean energy technologies means strengthening the economy while protecting the environment. This activity book for all ages promotes energy awareness, with facts on different types of energy and a variety of puzzles in an energy theme.

  7. Nickel-Catalyzed Cross-Coupling of Redox-Active Esters with Boronic Acids.

    PubMed

    Wang, Jie; Qin, Tian; Chen, Tie-Gen; Wimmer, Laurin; Edwards, Jacob T; Cornella, Josep; Vokits, Benjamin; Shaw, Scott A; Baran, Phil S

    2016-08-01

    A transformation analogous in simplicity and functional group tolerance to the venerable Suzuki cross-coupling between alkyl-carboxylic acids and boronic acids is described. This Ni-catalyzed reaction relies upon the activation of alkyl carboxylic acids as their redox-active ester derivatives, specifically N-hydroxy-tetrachlorophthalimide (TCNHPI), and proceeds in a practical and scalable fashion. The inexpensive nature of the reaction components (NiCl2 ⋅6 H2 O-$9.5 mol(-1) , Et3 N) coupled to the virtually unlimited commercial catalog of available starting materials bodes well for its rapid adoption. PMID:27380912

  8. Cross section measurement on 139La (γ,γ') below neutron separation energy

    NASA Astrophysics Data System (ADS)

    Makinaga, A.; Rusev, G.; Schwengner, R.; Dönau, F.; Beyer, R.; Bemmerer, D.; Crespo, P.; Erhard, M.; Junghans, A. R.; Klug, J.; Nair, C.; Schilling, K. D.; Wagner, A.

    2010-06-01

    The γ-ray strength function is an important input quantity for the determination of the photoreaction rate and the neutron capture rate for astrophysics as well as for nuclear technologies. Recent studies show that extra γ-ray strength near the neutron separation energy Sn (pygmy resonance) affects the stellar reaction rate strongly. In this work, the photoabsorption cross section for 139La below Sn was measured using bremsstrahlung produced at the electron accelerator ELBE of Eorschungszentrum Dresden-Rossendorf with an electron beam of 11.5 MeV kinetic energy. Experimental result of 139La is presented.

  9. Light Charged-Particle Production Activation Cross Sections of Zr Isotopes from 14 to 20 MeV

    SciTech Connect

    Semkova, V.; Plompen, A.J.M.; Smith, D.L.

    2005-05-24

    Results of new cross-section measurements are presented for the following neutron-induced reactions: 90Zr(n,{alpha})87mSr, 90Zr(n,p)90mY, 91Zr(n,p)91mY, 91Zr(n,x)90mY, 92Zr(n,p)92Y, 92Zr(n,x)91mY, 94Zr(n,{alpha})91Sr, and 94Zr(n,p)94Y in the energy range from 14 to 21 MeV. Use was made of the activation technique in combination with high-resolution {gamma}-ray spectrometry. The irradiations were carried out at the 7-MV Van de Graaff accelerator at IRMM, Geel. Quasi-monoenergetic neutrons were produced via the 3H(d,n)4He reaction at 1, 2, 3, and 4 MeV incident deuteron energy. Both natural and samples enriched in 90Zr, 91Zr, and 92Zr were used to enhance the reaction yield or to facilitate correction for interfering reactions leading to the same product. The measured results are compared with work by other authors, TALYS-0.57 and EMPIRE-II model calculations, and current evaluated data files. Cross sections for all of the investigated reactions have been measured for the first time above 16 MeV.

  10. Production cross sections of products in the proton induced reactions on natNd in the energy region up to 45 MeV

    NASA Astrophysics Data System (ADS)

    Yang, Sung-Chul; Kim, Kwangsoo; Song, Tae-Yung; Lee, Young-Ouk; Kim, Guinyun

    2015-11-01

    The production cross sections of 141,143,144,146,148m,148g,149,150Pm, 139m,147,149Nd, 138m,142gPr, and 139gCe in the natNd(p,x) reactions were determined by a stacked-foil activation technique for the proton energy range up to 45 MeV using the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences. The measured cross sections were compared with literature data as well as data from the TENDL-2014 library based on TALYS 1.6. The production cross sections of the above radionuclides are slightly higher than the literature data but are in general agreement with values in TENDL-2014 library except for 148mPm, 148gPm, 139mNd, and 142gPr. The thick target integral yields of the produced radionuclides were also deducted from the measured cross sections.