Science.gov

Sample records for effective cross sections

  1. Coulomb and nuclear effects in breakup and reaction cross sections

    NASA Astrophysics Data System (ADS)

    Descouvemont, P.; Canto, L. F.; Hussein, M. S.

    2017-01-01

    We use a three-body continuum discretized coupled channel (CDCC) model to investigate Coulomb and nuclear effects in breakup and reaction cross sections. The breakup of the projectile is simulated by a finite number of square integrable wave functions. First we show that the scattering matrices can be split in a nuclear term and in a Coulomb term. This decomposition is based on the Lippmann-Schwinger equation and requires the scattering wave functions. We present two different methods to separate both effects. Then, we apply this separation to breakup and reaction cross sections of 7Li+208Pb . For breakup, we investigate various aspects, such as the role of the α +t continuum, the angular-momentum distribution, and the balance between Coulomb and nuclear effects. We show that there is a large ambiguity in defining the Coulomb and nuclear breakup cross sections, since both techniques, although providing the same total breakup cross sections, strongly differ for the individual components. We suggest a third method which could be efficiently used to address convergence problems at large angular momentum. For reaction cross sections, interference effects are smaller, and the nuclear contribution is dominant above the Coulomb barrier. We also draw attention to different definitions of the reaction cross section which exist in the literature and which may induce small, but significant, differences in the numerical values.

  2. Krypton charge exchange cross sections for Hall effect thruster models

    SciTech Connect

    Hause, Michael L.; Prince, Benjamin D.; Bemish, Raymond J.

    2013-04-28

    Following discharge from a Hall effect thruster, charge exchange occurs between ions and un-ionized propellant atoms. The low-energy cations produced can disturb operation of onboard instrumentation or the thruster itself. Charge-exchange cross sections for both singly and doubly charged propellant atoms are required to model these interactions. While xenon is the most common propellant currently used in Hall effect thrusters, other propellants are being considered, in particular, krypton. We present here guided-ion beam measurements and comparisons to semiclassical calculations for Kr{sup +} + Kr and Kr{sup 2+} + Kr cross sections. The measurements of symmetric Kr{sup +} + Kr charge exchange are in good agreement with both the calculations including spin-orbit effects and previous measurements. For the symmetric Kr{sup 2+} + Kr reaction, we present cross section measurements for center-of-mass energies between 1 eV and 300 eV, which spans energies not previously examined experimentally. These cross section measurements compare well with a simple one-electron transfer model. Finally, cross sections for the asymmetric Kr{sup 2+} + Kr {yields} Kr{sup +} + Kr{sup +} reaction show an onset near 12 eV, reaching cross sections near constant value of 1.6 A{sup 2} with an exception near 70-80 eV.

  3. Effect of strongly coupled plasma on photoionization cross section

    SciTech Connect

    Das, Madhusmita

    2014-01-15

    The effect of strongly coupled plasma on the ground state photoionization cross section is studied. In the non relativistic dipole approximation, cross section is evaluated from bound-free transition matrix element. The bound and free state wave functions are obtained by solving the radial Schrodinger equation with appropriate plasma potential. We have used ion sphere potential (ISP) to incorporate the plasma effects in atomic structure calculation. This potential includes the effect of static plasma screening on nuclear charge as well as the effect of confinement due to the neighbouring ions. With ISP, the radial equation is solved using Shooting method approach for hydrogen like ions (Li{sup +2}, C{sup +5}, Al{sup +12}) and lithium like ions (C{sup +3}, O{sup +5}). The effect of strong screening and confinement is manifested as confinement resonances near the ionization threshold for both kinds of ions. The confinement resonances are very much dependent on the edge of the confining potential and die out as the plasma density is increased. Plasma effect also results in appearance of Cooper minimum in lithium like ions, which was not present in case of free lithium like ions. With increasing density the position of Cooper minimum shifts towards higher photoelectron energy. The same behaviour is also true for weakly coupled plasma where plasma effect is modelled by Debye-Huckel potential.

  4. Gravitational lensing frequencies - Galaxy cross-sections and selection effects

    NASA Technical Reports Server (NTRS)

    Fukugita, Masataka; Turner, Edwin L.

    1991-01-01

    Four issues - (1) the best currently available data on the galaxy velocity-dispersion distribution, (2) the effects of finite core radii potential ellipticity on lensing cross sections, (3) the predicted distribution of lens image separations compared to observational angular resolutions, and (4) the preferential inclusion of lens systems in flux limited samples - are considered in order to facilitate more realistic predictions of multiple image galaxy-quasar lensing frequencies. It is found that (1) the SIS lensing parameter F equals 0.047 +/-0.019 with almost 90 percent contributed by E and S0 galaxies, (2) observed E and S0 core radii are remarkably small, yielding a factor of less than about 2 reduction in total lensing cross sections, (3) 50 percent of galaxy-quasar lenses have image separations greater than about 1.3 arcsec, and (4) amplification bias factors are large and must be carefully taken into account. It is concluded that flat universe models excessively dominated by the cosmological constant are not favored by the small observed galaxy-quasar lensing rate.

  5. Reducing cross-sectional data using a genetic algorithm method and effects on cross-section geometry and steady-flow profiles

    USGS Publications Warehouse

    Berenbrock, Charles E.

    2015-01-01

    The effects of reduced cross-sectional data points on steady-flow profiles were also determined. Thirty-five cross sections of the original steady-flow model of the Kootenai River were used. These two methods were tested for all cross sections with each cross section resolution reduced to 10, 20 and 30 data points, that is, six tests were completed for each of the thirty-five cross sections. Generally, differences from the original water-surface elevation were smaller as the number of data points in reduced cross sections increased, but this was not always the case, especially in the braided reach. Differences were smaller for reduced cross sections developed by the genetic algorithm method than the standard algorithm method.

  6. Jet inclusive cross sections

    SciTech Connect

    Del Duca, V.

    1992-11-01

    Minijet production in jet inclusive cross sections at hadron colliders, with large rapidity intervals between the tagged jets, is evaluated by using the BFKL pomeron. We describe the jet inclusive cross section for an arbitrary number of tagged jets, and show that it behaves like a system of coupled pomerons.

  7. Effects of cross-section on mechanical properties of Au nanowire

    SciTech Connect

    Vazinishayan, Ali; Yang, Shuming Duongthipthewa, Anchalee; Wang, Yiming

    2016-02-15

    The aim of this paper is study of the effects of multiple cross-section of Au nanowire on mechanical properties. Different cross-section models of Au nanowires including circular, hexagonal, pentagonal and rectangular were simulated by finite element modeling using ABAQUS. In this study, the bending technique was applied so that both ends of the model were clamped with mid-span under loading condition. The cross-sections had the length of 400 nm and the diameter of 40 nm, except the circular cross-section while the rest of the cross-sections had an equivalent diameter. Von Misses stresses distribution were used to define the stress distribution in the cross-section under loading condition, and elastic deformation was analyzed by the beam theory. The results disclosed that the circular and the rectangular models had highest and lowest strengths against plastic deformation, respectively.

  8. Experiment to measure total cross sections, differential cross sections and polarization effects in pp elastic scattering at RHIC

    SciTech Connect

    Guryn, W.

    1998-02-01

    The authors are describing an experiment to study proton-proton (pp) elastic scattering experiment at the Relativistic Heavy Ion Collider (RHIC). Using both polarized and unpolarized beams, the experiment will study pp elastic scattering from {radical}s = 50 GeV to {radical}s = 500 GeV in two kinematical regions. In the Coulomb Nuclear Interference (CNI) region, 0.0005 < {vert_bar}t{vert_bar} < 0.12 (GeV/c){sup 2}, they will measure and study the s dependence of the total and elastic cross sections, {sigma}{sub tot} and {sigma}{sub el}; the ratio of the real to the imaginary part of the forward elastic scattering amplitude, {rho}; and the nuclear slope parameter of the pp elastic scattering, b. In the medium {vert_bar}t{vert_bar}-region, {vert_bar}t{vert_bar} < 1.5 (GeV/c){sup 2}, they plan to study the evolution of the dip structure with s, as observed at ISR in the differential elastic cross section, d{sigma}{sub el}/dt, and the s and {vert_bar}t{vert_bar} dependence of b. With the polarized beams the following can be measured: the difference in the total cross sections as function of initial transverse spin states {Delta}{sigma}{sub T}, the analyzing power, A{sub N}, and the transverse spin correlation parameter A{sub NN}. The behavior of the analyzing power A{sub N} at RHIC energies in the dip region of d{sigma}{sub el}/dt, where a pronounced structure was found at fixed-target experiments will be studied. The relation of pp elastic scattering to the beam polarization measurement at RHIC is also discussed.

  9. 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.

  10. 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.

  11. Cross-sectional study on respiratory effect of toner exposure.

    PubMed

    Terunuma, Niina; Kurosaki, Shizuka; Kitamura, Hiroko; Hata, Koichi; Ide, Reiko; Kuga, Hiroaki; Kakiuchi, Noriaki; Masuda, Masashi; Totsuzaki, Takafumi; Osato, Atsushi; Uchino, Bungo; Kitahara, Kayo; Iwasaki, Akio; Yoshizumi, Koji; Morimoto, Yasuo; Kasai, Hiroshi; Murase, Tadashi; Higashi, Toshiaki

    2009-06-01

    In this baseline study, part of a cohort study to clarify the effect of toner exposure on the respiratory system, we surveyed 803 male toner workers and 802 referents with regard to their subjective respiratory symptoms and chest X-ray results. We also examined individual exposure history, current working conditions, and personal exposure levels to toner. There was a significantly higher prevalence of "coughing and sputum" related complaints among toner-exposed workers in the 30 and 40-year age groups. The group with toner-exposure history showed a higher odds ratio, by logistic regression, in relation to all questions regarding coughing. Mild fibrotic changes were observed in the chest X-rays of four workers who had engaged in toner-exposure work for at least a decade or more, and all four had reported allergic disease. Although we observed a tendency of higher prevalence of "coughing and sputum" in toner-exposed workers, the possibility of information bias cannot be eliminated. It should also be noted that this tendency did not exceed that of the general public. Further analysis is required in this ongoing 10-year cohort study to clarify the effect of toner exposure on the respiratory system.

  12. Cross-section Effects in the Super-Kamiokande Tau Appearance Analysis

    SciTech Connect

    Walter, Christopher

    2011-11-23

    In this talk, I explain the search for tau neutrino appearance in the atmospheric neutrino flux at Super-Kamiokande with a particular emphasis on the effect deep inelastic cross section uncertainties have on interpreting the result. In particular, I explain why the normalization of the DIS cross-section also needs to be treated as a parameter in the fit of tau normalization, and show how a neural net based on event parameters can separate various cross-section modes in the background sample.

  13. Stratospheric Determination of Effective Photodissociation Cross Sections for Molecular Oxygen: 191-204 nm

    DTIC Science & Technology

    1983-10-20

    near 200 nm, is greater than expected, indicating that the recoin- mended 6 02 Herzberg continuum cross sections may be too large. Photo- -~ chemical...ToT(A) convolved with altitude-dependent effective absorption cross sections, t’eff(ZAX)9󈧎 (Allen & Frederick , 1982, ref. 10, will subsequently be 1...The preliminary data from that flight will be used to augment this study and tighten the error estimates. IV. Theory: As Allen and Frederick 10

  14. Cost-Effective Optimization of Rubble-Mound Breakwater Cross Sections.

    DTIC Science & Technology

    1986-02-01

    a step-wise procedure is presented which can identify an optimum breakwater cross section, both in terms of structural integrity and functional I...District offices, can formulate an optimum cross-section configuration and verify its effectiveness, both in terms of structural integrity and functional...criterion can be referred to as the "structural integrity " or "survival" criterion. The second type, referred to as the "functional performance

  15. Geometric effect on photonic nanojet generated by dielectric microcylinders with non-cylindrical cross-sections

    NASA Astrophysics Data System (ADS)

    Liu, Cheng-Yang; Lin, Fan-Chih

    2016-12-01

    We experimentally report the geometric effect on photonic nanojet generated by dielectric microcylinders with non-cylindrical cross-sections. The non-cylindrical cross-sections include truncated microcylinders and elliptical microcylinders. The truncated microcylinder is formed with the cutting thickness. The elliptical microcylinder is defined by ratio of minor to major axes. The specific spatial electromagnetic fields for microcylinders with different non-cylindrical cross-sections are studied by using finite-difference time-domain calculation. The direct imaging of photonic nanojets for microcylinders with different non-cylindrical cross-sections are performed with a scanning optical microscope system. The field distribution and location of photonic nanojet depending on the various spatial shapes are experimentally demonstrated. The photonic nanojet with long focal length and low divergence could be used to scan over a target to obtain a large area image when the non-cylindrical micro-media are coupled with a conventional optical microscope.

  16. 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.

  17. Space, energy and anisotropy effects on effective cross sections and diffusion coefficients in the resonance region

    SciTech Connect

    Meftah, B.

    1982-01-01

    Present methods used in reactor analysis do not include adequately the effect of anisotropic scattering in the calculation of resonance effective cross sections. Also the assumption that the streaming term ..cap omega...del Phi is conserved when the total, absorption and transfer cross sections are conserved, is bad because the leakage from a heterogeneous cell will not be conserved and is strongly anisotropic. A third major consideration is the coupling between different regions in a multiregion reactor; currently this effect is being completely ignored. To assess the magnitude of these effects, a code based on integral transport formalism with linear anisotropic scattering was developed. Also, a more adequate formulation of the diffusion coefficient in a heterogeneous cell was derived. Two reactors, one fast, ZPR-6/5, and one thermal, TRX-3, were selected for the study. The study showed that, in general, the inclusion of linear scattering anisotropy increases the cell effective capture cross section of U-238. The increase was up to 2% in TRX-3 and 0.5% in ZPR-6/5. The effect on the multiplication factor was -0.003% ..delta..k/k for ZPR-6/5 and -0.05% ..delta..k/k for TRX-3. For the case of the diffusion coefficient, the combined effect of heterogeneity and linear anisotropy gave an increase of up to 29% in the parallel diffusion coefficient of TRX-3 and 5% in the parallel diffusion coefficient of ZPR-6/5. In contrast, the change in the perpendicular diffusion coefficient did not exceed 2% in both systems.

  18. Validation of Cross Sections for Monte Carlo Simulation of the Photoelectric Effect

    NASA Astrophysics Data System (ADS)

    Han, Min Cheol; Kim, Han Sung; Pia, Maria Grazia; Basaglia, Tullio; Batic, Matej; Hoff, Gabriela; Kim, Chan Hyeong; Saracco, Paolo

    2016-04-01

    Several total and partial photoionization cross section calculations, based on both theoretical and empirical approaches, are quantitatively evaluated with statistical analyses using a large collection of experimental data retrieved from the literature to identify the state of the art for modeling the photoelectric effect in Monte Carlo particle transport. Some of the examined cross section models are available in general purpose Monte Carlo systems, while others have been implemented and subjected to validation tests for the first time to estimate whether they could improve the accuracy of particle transport codes. The validation process identifies Scofield's 1973 non-relativistic calculations, tabulated in the Evaluated Photon Data Library(EPDL), as the one best reproducing experimental measurements of total cross sections. Specialized total cross section models, some of which derive from more recent calculations, do not provide significant improvements. Scofield's non-relativistic calculations are not surpassed regarding the compatibility with experiment of K and L shell photoionization cross sections either, although in a few test cases Ebel's parameterization produces more accurate results close to absorption edges. Modifications to Biggs and Lighthill's parameterization implemented in Geant4 significantly reduce the accuracy of total cross sections at low energies with respect to its original formulation. The scarcity of suitable experimental data hinders a similar extensive analysis for the simulation of the photoelectron angular distribution, which is limited to a qualitative appraisal.

  19. Effects of low-energy electrons on DNA constituents: effective cross sections for condensed thymidine

    NASA Astrophysics Data System (ADS)

    Panajotovic, Radmila

    2009-05-01

    Since the first experiments of low-energy electron scattering from condensed DNA [1] have been performed, the interest in studying low-energy electron-biomolecule interactions has been increasing. Knowledge of effective cross sections for single- and double-strand breaks of DNA and for vibrational and electronic excitation of nucleic bases and nucleosides are opening the door to better understanding of effects of radiation on live tissue and possibly indicating interaction pathways leading to gene mutations and cancer. The strong variation of effective cross sections for DNA single-strand breaks with incident electron energy and the resonant enhancement at 1 eV suggested that considerable damage is inflicted by very low-energy electrons to DNA, and indicates the important role of π* shape resonances in the bond-breaking process. However, the complexity of DNA, even if studied as a short single-strand chain, imposes a need to perform measurements on its isolated constituents, such as nucleic bases and nucleosides. Thymidine is one of the most important nucleosides of DNA and an important component of antiviral compounds. In the condensed phase, thymidine's 2'-deoxyribose ring is in the pentose sugar ring form, which is a true conformation of this nucleoside in DNA. Results from High-Resolution Electron Energy Loss [2] study of monomolecular films of thymidine will be discussed and the presence of resonances in the effective cross sections at incident energy below 5 eV will be commented as a possible indication of the dissociative electron attachment. In addition, results on the resonance structures in the effective cross sections for electronic excitations for the incident electron energy from 1.5 to 12 eV will be discussed as a possible pathway for strand brakes in DNA. [4pt] [1] Boudaiffa B, Cloutier P, Hunting D, Huels M A and Sanche L 2002 Rad. Res. 157 227-234[0pt] [2] Panajotovic R, Martin F, Cloutier P, Hunting, D, and Sanche L, 2006 Rad.Res. 165 452

  20. Effective inelastic scattering cross-sections for background analysis in HAXPES of deeply buried layers

    NASA Astrophysics Data System (ADS)

    Risterucci, P.; Renault, O.; Zborowski, C.; Bertrand, D.; Torres, A.; Rueff, J.-P.; Ceolin, D.; Grenet, G.; Tougaard, S.

    2017-04-01

    Inelastic background analysis of HAXPES spectra was recently introduced as a powerful method to get access to the elemental distribution in deeply buried layers or interfaces, at depth up to 60 nm below the surface. However the accuracy of the analysis highly relies on suitable scattering cross-sections able to describe effectively the transport of photoelectrons through overlayer structures consisting of individual layers with potentially very different scattering properties. Here, we show that within Tougaard's practical framework as implemented in the Quases-Analyze software, the photoelectron transport through thick (25-40 nm) multi-layer structures with widely different cross-sections can be reliably described with an effective cross-section in the form of a weighted sum of the individual cross-section of each layer. The high-resolution core-level analysis partly provides a guide for determining the nature of the individual cross-sections to be used. We illustrate this novel approach with the practical case of a top Al/Ti bilayer structure in an AlGaN/GaN power transistor device stack before and after sucessive annealing treatments. The analysis provides reliable insights on the Ti and Ga depth distributions up to nearly 50 nm below the surface.

  1. The Effect of Using Dynamic Mathematics Software: Cross Section and Visualization

    ERIC Educational Resources Information Center

    Kösa, Temel

    2016-01-01

    The main purpose of this study is to determine the effects of using dynamic mathematics software on pre-service mathematics teachers' ability to infer the shape of a cross section of a three-dimensional solid, as well as on their spatial visualization skills. The study employed a quasi-experimental design with a control group; the Purdue Spatial…

  2. Use of Relativistic Effective Core Potentials in the Calculation of Electron-Impact Ionization Cross Sections

    NASA Technical Reports Server (NTRS)

    Huo, Winifred M.; Kim, Yong-Ki

    1999-01-01

    Based on the Binary-Encounter-Bethe (BEB) model, the advantage of using relativistic effective core potentials (RECP) in the calculation of total ionization cross sections of heavy atoms or molecules containing heavy atoms is discussed. Numerical examples for Ar, Kr, Xe, and WF6 are presented.

  3. Effective photodissociation cross sections for molecular oxygen and nitric oxide in the Schumann-Runge bands

    NASA Technical Reports Server (NTRS)

    Allen, M.; Frederick, J. E.

    1982-01-01

    Accurate calculations of the atmospheric opacity and the photodissociation rate of molecular oxygen in the Schumann-Runge bands (175-205) are necessary for modeling chemistry in the terrestrial upper atmosphere. The present investigation is concerned with a single simple parameterization of effective cross sections which can be used to calculate both O2 opacity and dissociation rates. Use is made of a zenith angle dependent factor which accounts for variations shown in detailed calculations. The conducted analysis is based on the results of Frederick and Hudson (1980). Attention is given to molecular oxygen effective cross sections and nitric oxide effective cross sections. It is found that the depth of the atmosphere to which solar radiation in the 175-200 nm spectral region penetrates is a sensitive function of the rotational line widths in the Schumann-Runge bands. The oscillator strength for each band measures the cross section integrated over the band while the line width determine how the absorption is distributed in wavenumber.

  4. New Arsenic Cross Section Calculations

    SciTech Connect

    Kawano, Toshihiko

    2015-03-04

    This report presents calculations for the new arsenic cross section. Cross sections for 73,74,75 As above the resonance range were calculated with a newly developed Hauser-Feshbach code, CoH3.

  5. Doppler broadening effect on collision cross section functions - Deconvolution of the thermal averaging

    NASA Technical Reports Server (NTRS)

    Bernstein, R. B.

    1973-01-01

    The surprising feature of the Doppler problem in threshold determination is the 'amplification effect' of the target's thermal energy spread. The small thermal energy spread of the target molecules results in a large dispersion in relative kinetic energy. The Doppler broadening effect in connection with thermal energy beam experiments is discussed, and a procedure is recommended for the deconvolution of molecular scattering cross-section functions whose dominant dependence upon relative velocity is approximately that of the standard low-energy form.

  6. Effects of Pb and Bi cross sections on ATW subcriticality predictions.

    SciTech Connect

    Khalil, H. S.; Yang, W. S.

    1999-06-25

    The accelerator-driven transmutation of waste (ATW) system has been proposed for transmuting the long-lived radioactive nuclei of high-level waste to stable or short-lived species. In recent ATW design concepts, lead-bismuth eutectic (LBE), consisting of 44.5% Pb and 55.5% Bi by weight is used as the spallation target, system coolant, and reflector. Because of the excellent neutron reflection properties of LBE, the subcriticality level of ATW is quite sensitive to the cross sections of lead and bismuth. The purpose of this paper is to investigate the effects of these cross sections on subcriticality and other core characteristics of ATW and to compare the results obtained using cross sections in different evaluated nuclear data files. The effects of lead and bismuth cross sections on the core characteristics of ATW were studied using 33 group cross section sets derived from the ENDF/B-VI, ENDF/B-V, JENDL-3.2, and BROND-2.2 nuclear data. A 2000 MW(thermal) ATW configuration similar to that described in Reference 1 was used in this study. In this configuration, the spallation target region is 55 cm high and 25 cm in radius, and is surrounded by a 15-cm thick LBE buffer. The adjacent fueled region is {approximately}65 cm thick and 200 cm high. The volume fractions of fuel, coolant, and structure are 25.7%, 59.3%, and 15%, respectively. The metal alloy fuel is composed of roughly 70% zirconium, 25% transuranics (TRU), and 5% Tc-99 by weight. A thick LBE reflector surrounds the whole core; its axial thickness is 250 cm, and its radial thickness is 295.2 cm.

  7. The effects of ablation on the cross section of planetary envelopes at capturing planetesimals

    NASA Astrophysics Data System (ADS)

    Benvenuto, Omar G.; Brunini, Adrián

    2008-06-01

    We explore the cross section of giant planet envelopes at capturing planetesimals of different sizes. For this purpose we employ two sets of realistic planetary envelope models (computed assuming for the protoplanetary nebula masses of 10 and 5 times the mass of the minimum mass solar nebula), account for drag and ablation effects and study the trajectories along which planetesimals move. The core accretion of these models has been computed in the oligarchic growth regime [Fortier, A., Benvenuto, O.G., Brunini, A., 2007. Astron. Astrophys. 473, 311-322], which has also been considered for the velocities of the incoming planetesimals. This regime predicts velocities larger that those used in previous studies of this problem. As the rate of ablation is dependent on the third power of velocity, ablation is more important in the oligarchic growth regime. We compute energy and mass deposition, fractional ablated masses and the total cross section of planets for a wide range of values of the critical parameter of ablation. In computing the total cross section of the planet we have included the contributions due to mass deposited by planetesimals moving along unbound orbits. Our results indicate that, for the case of small planetary cores and low velocities for the incoming planetesimals, ablation has a negligible impact on the capture cross section in agreement with the results presented in Inaba and Ikoma [Inaba, S., Ikoma, M., 2003. Astron. Astrophys. 410, 711-723]. However for the case of larger cores and high velocities of the incoming planetesimals as predicted by the oligarchic growth regime, we find that ablation is important in determining the planetary cross section, being several times larger than the value corresponding ignoring ablation. This is so regardless of the size of the incoming planetesimals.

  8. Interaction driver-bicyclist on rural roads: Effects of cross-sections and road geometric elements.

    PubMed

    Bella, Francesco; Silvestri, Manuel

    2017-03-17

    The interaction of motorists and bicyclists, particularly during passing maneuvers, is cited as one of the primary causes of bicyclist fatalities. This paper reports the results of a driving simulator study, which sought to analyze the effects that three cross-section configurations of a two-lane rural road and four geometric elements of the road have on driver behavior, during the interaction with a cyclist. A two-lane rural road, about 11km long, was designed and implemented in an advanced-interactive driving simulator. Three different cross-sections (all with same width, but with and without a bicycle lane and for different widths of bicycle lane) were tested. Forty participants carried out three driving sessions (one for each road alignment with different cross-section) and were exposed to the condition of bicycle traffic along four geometric elements of the alignment (2 tangents with different lengths, right curve and left curve). The driving simulator experiments were designed in such a way that, along the sections where the driver-cyclist interactions occurred, the oncoming traffic was absent. Overall, 468 speed profiles and 468 lateral position profiles were plotted to obtain the descriptive variables of the driver behavior during the interaction with the cyclist. The influences of cross-sections, geometric elements and bicycle traffic conditions on driver behavior were evaluated by a multivariate variance analysis. The presence of the cyclist determined different levels of influence on driver's trajectory for the three cross-sections. A wider bicycle lane ensured a higher later clearance distance between driver and cyclist, allowing safer overtaking maneuver. The interferences of the cyclist on driver's behavior depended on the geometric elements. On tangents, the lowest lateral clearances were recorded and no speed reduction was observed, compared to the cyclist absence condition. On the left curve, the higher lateral clearance was recorded, due to the

  9. Effect of light state transitions on the apparent absorption cross section of Photosystem II in Chlorella

    SciTech Connect

    Falkowski, P.G.; Fujita, Yoshihiko

    1986-01-01

    The distribution of excitation energy between photosystems may profoundly affect the quantum yield of photosynthetic oxygen evolution. Excitation energy absorbed by pigment molecules is transferred to reaction centers, where it may potentially drive a photochemical event. To balance the photochemical events in PSII with those in PSI, excitation energy may be transferred between PSII and PSI. This type of energy transfer has been inferred primarily in the steady state quantum yield of oxygen evolution and/or fluorescence with changes in excitation wavelength. These so called ''state transitions'' have been attributed to changes in either the absorption cross section of PSII or ''spillover'' of excitation energy between the two photosystems. We report here on measurements of relative absorption cross sections of PSII under state I and state II light conditions. We simultaneously followed the yields of O/sub 2/ and the change in fluorescence yields, ..delta.. phi, as a function of flash energy using single turnover xenon flashes. Our data suggest that the effective absorption cross section of PSII does not change within +- 10% under physiological conditions in unpoisoned Chlorella pyrenoidosa. 13 refs., 3 figs.

  10. Solid-state effects on thermal-neutron cross sections and on low-energy resonances

    SciTech Connect

    Harvey, J.A.; Mook, H.A.; Hill, N.W.; Shahal, O.

    1982-01-01

    The neutron total cross sections of several single crystals (Si, Cu, sapphire), several polycrystalline samples (Cu, Fe, Be, C, Bi, Ta), and a fine-powder copper sample have been measured from 0.002 to 5 eV. The Cu powder and polycrystalline Fe, Be and C data exhibit the expected abrupt changes in cross section. The cross section of the single crystal of Si is smooth with only small broad fluctuations. The data on two single Cu crystals, the sapphire crystal, cast Bi, and rolled samples of Ta and Cu have many narrow peaks approx. 10/sup -3/ eV wide. High resolution (0.3%) transmission measurements were made on the 1.057-eV resonance in /sup 240/Pu and the 0.433-eV resonance in /sup 180/Ta, both at room and low temperatures to study the effects of crystal binding. Although the changes in Doppler broadening with temperature were apparent, no asymmetries due to a recoilless contribution were observed.

  11. Effects of space-dependent cross sections on core physics parameters for compact fast spectrum space power reactors

    NASA Astrophysics Data System (ADS)

    Lell, R. M.; Hanan, N. A.

    Effects of multigroup neutron cross section generation procedures on core physics parameters for compact fast spectrum reactors were examined. Homogeneous and space dependent multigroup cross section set were generated in 11 and 27 groups for a representative fast reactor core. These cross sections were used to compute various reactor physics parameters for the reference core. Coarse group structure and neglect of space dependence in the generation procedure resulted in inaccurate computations of reactor flux and power distributions and in significant errors regarding estimates of core reactivity and control system worth. Delayed neutron fraction was insensitive to cross section treatment, and computed reactivity coefficients were only slightly sensitive. However, neutron lifetime was found to be very sensitive to cross section treatment. Deficiencies in multigroup cross sections are reflected in core nuclear design and, consequently, in system mechanical design.

  12. Effect of cross-sectional shape on the propagation characteristics of fundamental plasmon mode guided along Au and Ag nanowires

    NASA Astrophysics Data System (ADS)

    Jitender; Kumar, Arun

    2017-01-01

    We numerically examine the effect of the cross-sectional shape on the propagation characteristics of the fundamental surface plasmon polariton (SPP) mode guided along Au and Ag nanowires. It is observed that as the cross-sectional symmetry decreases from circular to triangular via pentagonal and square, the modal confinement, loss and dispersion increases. Further the difference in propagation characteristics between circular and other cross-sections increases rapidly as the wavelength of operation decreases. The study should be useful for selecting the cross-sectional shape of the nanowire for a particular application.

  13. Radar cross section of insects

    NASA Astrophysics Data System (ADS)

    Riley, J. R.

    1985-02-01

    X-band measurements of radar cross section as a function of the angle between insect body axis and the plane of polarization are presented. A finding of particular interest is that in larger insects, maximum cross section occurs when the E-vector is perpendicular to the body axis. A new range of measurements on small insects (aphids, and planthoppers) is also described, and a comprehensive summary of insect cross-section data at X-band is given.

  14. CROSS-SECTIONAL AND LONGITUDINAL MEASUREMENTS OF NEIGHBORHOOD EXPERIENCE AND THEIR EFFECTS ON CHILDREN*

    PubMed Central

    Jackson, Margot I.; Mare, Robert D.

    2014-01-01

    Despite the abundance of research on neighborhoods’ effects on children, most studies of neighborhood effects are cross-sectional, rendering them unable to depict the dynamic nature of social life, and obscuring important aspects of community processes and outcomes. This study uses residential histories from the Los Angeles Family and Neighborhood Survey and the Child Development Supplement of the Panel Study of Income Dynamics to explore two questions: 1) How much do residential mobility and neighborhood change contribute to the overall socioeconomic variation in children’s neighborhoods? 2) Does measuring community factors at more than one point in time matter for the conclusions that we draw from research on “neighborhood effects” on children’s behavioral, cognitive and health-related well-being? Residential mobility plays a non-trivial role over the period of childhood in determining children’s exposure to neighborhoods of different economic types. However, quantitative estimates of neighborhood effects that allow neighborhood characteristics to vary through residential mobility and neighborhood change do not depict a strikingly different picture from cross-sectional estimates. Children do not experience enough variation in their local surroundings to produce meaningful differences between static and dynamic measurements of neighborhoods. We also uncover interesting regional and race/ethnic differences in neighborhood dynamics and neighborhood effects. PMID:25197150

  15. Radar Cross Section Measurements

    DTIC Science & Technology

    1986-09-30

    Radar 54 17. Measured Range Sidelobe Performance of Chirp Radar 56 18. Range and Cross Range Image of Target Dror.’ŕ Vehicle 57 19. Incoherent rms...the measured range resolution, 4.9 in, closely agrees with the theoretical performance for this weighting. The measured range sidelobe performance...Interval 4.89in. 2% kHz 300 kHz 310 kHz (b) Expanded Scale + 5 ft from Target Figure 17. Measured Range Sidelobe Performance of

  16. XCOM: Photon Cross Sections Database

    National Institute of Standards and Technology Data Gateway

    SRD 8 XCOM: Photon Cross Sections Database (Web, free access)   A web database is provided which can be used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, for any element, compound or mixture (Z <= 100) at energies from 1 keV to 100 GeV.

  17. Effective absorption cross sections and photolysis rates of anthropogenic and biogenic secondary organic aerosols

    NASA Astrophysics Data System (ADS)

    Romonosky, Dian E.; Ali, Nujhat N.; Saiduddin, Mariyah N.; Wu, Michael; Lee, Hyun Ji (Julie); Aiona, Paige K.; Nizkorodov, Sergey A.

    2016-04-01

    Mass absorption coefficient (MAC) values were measured for secondary organic aerosol (SOA) samples produced by flow tube ozonolysis and smog chamber photooxidation of a wide range of volatile organic compounds (VOC), specifically: α-pinene, β-pinene, β-myrcene, d-limonene, farnesene, guaiacol, imidazole, isoprene, linalool, ocimene, p-xylene, 1-methylpyrrole, and 2-methylpyrrole. Both low-NOx and high-NOx conditions were employed during the chamber photooxidation experiments. MAC values were converted into effective molecular absorption cross sections assuming an average molecular weight of 300 g/mol for SOA compounds. The upper limits for the effective photolysis rates of SOA compounds were calculated by assuming unity photolysis quantum yields and convoluting the absorption cross sections with a time-dependent solar spectral flux. A more realistic estimate for the photolysis rates relying on the quantum yield of acetone was also obtained. The results show that condensed-phase photolysis of SOA compounds can potentially occur with effective lifetimes ranging from minutes to days, suggesting that photolysis is an efficient and largely overlooked mechanism of SOA aging.

  18. Target correlation effects on neutron-nucleus total, absorption, and abrasion cross sections

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Townsend, Lawrence W.; Wilson, John W.

    1991-01-01

    Second order optical model solutions to the elastic scattering amplitude were used to evaluate total, absorption, and abrasion cross sections for neutron nucleus scattering. Improved agreement with experimental data for total and absorption cross sections is found when compared with first order (coherent approximation) solutions, especially below several hundred MeV. At higher energies, the first and second order solutions are similar. There are also large differences in abrasion cross section calculations; these differences indicate a crucial role for cluster knockout in the abrasion step.

  19. Cross Sections for Planetary Escape

    NASA Astrophysics Data System (ADS)

    Tully, C.

    2001-05-01

    Energetic charged-particle bombardment, dissociative recombination and photodissociation processes produce energetic recoil atoms which heat the thermosphere and can lead to escape from a planet affecting the evolution of the atmosphere. In describing these processes by Monte Carlo methods, many of the critical cross sections are not available in the energy range of interest, a few eV to 1 keV. Here we present our recent results for elastic collision and collisional dissociation cross sections relevant to Titan, Triton, Europa and the terrestrial planets [1,2]. Elastic and diffusion cross sections were calculated using both quantum mechanical techniques and the semiclassical JWKB approximation for the collision of ground state oxygen atoms in the energy range 1-10eV [2]. This involved calculation of phase shifts for each of the 18 molecular energy states of O2 which separate to two ground state O atoms. For an O thermosphere the total elastic cross section is close to that typically assumed but the escape depths are shown to be larger than those typically used. Dissociation cross sections of N + N2 were calculated using a semiclassical method, in the energy range 0-30eV. This required treating the vibrational motion quantum mechanically while the rotational and the relative translational motion were treated classically. The evolution of the system was calculated by simultaneous propagation of the classical as well as the quantal degrees of freedom. The solution to the classical part was carried out by solving Hamilton equations of motion using an effective London-Eyring-Polanyi-Sato potential energy surface, calculated by Laganá et al [3]. Propagation of the quantal wavefunction was carried out by solving the time dependent Schrödinger equation using the split operator technique with the help of the fast fourier transform which was used to calculate the second derivatives arising from the kinetic energy operator. This work was supported by NASA's Planetary

  20. Cross-Sectional Deformations of Monocoque Beams and Their Effects on the Natural Vibration Frequencies

    NASA Technical Reports Server (NTRS)

    Thomson, Robert G.; Kruszewski, Edwin T.

    1961-01-01

    The variational principle, differential equations, and boundary conditions governing the cross-sectional distortions due to inertia loading of a two-dimensional model of a thin monocoque wing are shown. A theoretical analysis of this simplified model is made in order to determine the nature of the coupling between the cross-sectional modes and the spanwise deformation modes. General solutions are obtained in finite-difference form for arbitrary cross sections and an exact solution is presented for a parabolic-arc cross section of constant cover thickness. The application of these results in evaluating the coupled frequencies of the actual structure is discussed. Frequencies evaluated for a parabolic-arc monocoque beam show good agreement with experimental values.

  1. Annular-Cross-Section CFE Chamber

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

  2. Effects of meteor head plasma distribution on radar cross sections and derived meteoroid masses

    NASA Astrophysics Data System (ADS)

    Marshall, R. A.; Close, S.; Brown, P.; Dimant, Y.

    2016-01-01

    We present calculations that relate meteor head echo radar cross sections to the meteor head plasma distribution. We use a forward model of radar scattering from meteor plasma using a finite-difference time-domain (FDTD) model of the electromagnetic wave interaction with the plasma. This model computes the meteor head RCS for a given meteor plasma distribution, specified with a peak plasma density and a characteristic size. We then relate measured RCS values to the input size and density parameters to better characterize the meteor plasma. We present simulation results that show that the RCS is directly related to the overdense meteor area; that is, the cross-section area of the meteor inside which the plasma frequency exceeds the radar frequency. This provides a direct estimate of the meteor plasma size from a given RCS measurement. Next we investigate the effect of the assumed plasma distribution. We study the RCS resulting from Gaussian, parabolic exponential and 1/r2 distributions. Comparing the different calculated RCS from these different distributions to three-frequency head echo data from the CMOR radar, we show that the 1/r2 distribution provides the best fit to the data. However, given uncertainties in the data, we cannot conclude that any distribution is the most valid. In addition, we show that the choice of distribution assumed can alter the resulting line density q by an order of magnitude for the same data.

  3. Inelastic cross sections for low-energy electrons in liquid water: exchange and correlation effects.

    PubMed

    Emfietzoglou, Dimitris; Kyriakou, Ioanna; Garcia-Molina, Rafael; Abril, Isabel; Nikjoo, Hooshang

    2013-11-01

    Low-energy electrons play a prominent role in radiation therapy and biology as they are the largest contributor to the absorbed dose. However, no tractable theory exists to describe the interaction of low-energy electrons with condensed media. This article presents a new approach to include exchange and correlation (XC) effects in inelastic electron scattering at low energies (below ∼10 keV) in the context of the dielectric theory. Specifically, an optical-data model of the dielectric response function of liquid water is developed that goes beyond the random phase approximation (RPA) by accounting for XC effects using the concept of the many-body local-field correction (LFC). It is shown that the experimental energy-loss-function of liquid water can be reproduced by including into the RPA dispersion relations XC effects (up to second order) calculated in the time-dependent local-density approximation with the addition of phonon-induced broadening in N. D. Mermin's relaxation-time approximation. Additional XC effects related to the incident and/or struck electrons are included by means of the vertex correction calculated by a modified Hubbard formula for the exchange-only LFC. Within the first Born approximation, the present XC corrections cause a significantly larger reduction (∼10-50%) to the inelastic cross section compared to the commonly used Mott and Ochkur approximations, while also yielding much better agreement with the recent experimental data for amorphous ice. The current work offers a manageable, yet rigorous, approach for including non-Born effects in the calculation of inelastic cross sections for low-energy electrons in liquid water, which due to its generality, can be easily extended to other condensed media.

  4. A Study of the Effects of Material Type and Configuration on Optical Cross Section

    NASA Astrophysics Data System (ADS)

    Feirstine, K.; Yarbrough, J.; Sharples, R.; Crosher, C.; Bowers, D.; Wellems, D.; Jenkins, G.; Rosprim, D.; Duggin, M.; Vaughn, L.

    2012-09-01

    An experiment was designed to study the effects of material type and configuration on Optical Cross Section (OCS) and spectrum. The experiment was conducted at an Air Force Research Laboratory (AFRL) far-field imaging facility, using different diffuse and specular materials and different configurations and/or combinations of each. It was hypothesized that the OCS of certain combinations of materials is dependent on the diffuseness or specularity of the materials used, but the spectrum is independent of these factors and does not change. The objective of the experiment is to capture both OCS and spectra of different material configurations using different combinations of diffuse and specular materials in the bi-static illumination condition. OCS was calculated relative to the scattering of a Spectralon material that was in the scene at all times. Results show the accurateness of the above hypothesis and illustrate other effects that material type and configuration have on OCS and spectra.

  5. Neutron capture cross section of 102Pd

    NASA Astrophysics Data System (ADS)

    Duncan, C. L.; Krane, K. S.

    2005-05-01

    The cross sections for radiative neutron capture by 102Pd have been deduced from a measurement of the γ rays emitted by 17.0-d 103Pd. The thermal cross section has been determined to be σ=1.82±0.20 b, and the effective resonance integral is I=23±4 b. We also report thermal and resonance capture cross sections for 108Pd and note possible inconsistencies with the presently accepted values of the 110Pd cross sections.

  6. Collisional Excitation Cross Sections.

    DTIC Science & Technology

    1984-08-01

    involving hydrogen atoms at low temperatures (typically 200 to 600 K), quantum mechanical tunneling effects are very important. A consistent method for...theory to use VTST semiempirically, e.g., to predict high- temperature rate constants from low - temperature ones. Because of its reliability, VTST was...comparison of the predicted rates permited an assessment of the reliability of the trajectory rates; the latter became unreliable at low temperatures for

  7. Elastic Differential Cross Sections

    NASA Technical Reports Server (NTRS)

    Werneth, Charles M.; Maung, Khin M.; Ford, William P.; Norbury, John W.; Vera, Michael D.

    2014-01-01

    The eikonal, partial wave (PW) Lippmann-Schwinger, and three-dimensional Lippmann-Schwinger (LS3D) methods are compared for nuclear reactions that are relevant for space radiation applications. Numerical convergence of the eikonal method is readily achieved when exact formulas of the optical potential are used for light nuclei (A less than or equal to 16) and the momentum-space optical potential is used for heavier nuclei. The PW solution method is known to be numerically unstable for systems that require a large number of partial waves, and, as a result, the LS3D method is employed. The effect of relativistic kinematics is studied with the PW and LS3D methods and is compared to eikonal results. It is recommended that the LS3D method be used for high energy nucleon- nucleus reactions and nucleus-nucleus reactions at all energies because of its rapid numerical convergence and stability.

  8. Parametrizations and dynamical analysis of angle-integrated cross sections for double photoionization including nondipole effects

    SciTech Connect

    Istomin, Andrei Y.; Starace, Anthony F.; Manakov, N. L.; Meremianin, A. V.; Kheifets, A. S.; Bray, Igor

    2005-11-15

    Similarly to differential cross sections for one-electron photoionization, the doubly differential cross section for double photoionization (DPI) may be conveniently described by four parameters: the singly differential (with respect to energy sharing) cross section ({sigma}{sub 0}), the dipole asymmetry parameter ({beta}), and two nondipole asymmetry parameters ({gamma} and {delta}). Here we derive two model-independent representations for these parameters for DPI from a {sup 1}S{sub 0} atomic bound state: (i) in terms of one-dimensional integrals of the polarization-invariant DPI amplitudes and (ii) in terms of the exact two-electron reduced matrix elements. For DPI of He at excess energies, E{sub exc}, of 100 eV, 450 eV, and 1 keV, we present numerical results for the asymmetry parameters within the framework of the convergent close-coupling theory and compare them with results of lowest-order (in the interelectron interaction) perturbation theory (LOPT). The results for E{sub exc}=1 keV exhibit a nondipole asymmetry that is large enough to be easily measured experimentally. We find excellent agreement between our LOPT results and other theoretical predictions and experimental data for total cross sections and ratios of double to single ionization cross sections for K-shell DPI from several multielectron atoms.

  9. 2p2h effects on the weak pion production cross section

    SciTech Connect

    Mariano, A.; Barbero, C.

    2015-05-15

    The ν{sub l}n → l{sup −}p QE reaction on the A-target is used as a signal event or/and to reconstruct the neutrino energy, using two-body kinematics. Competition of another processes could lead to misidentification of the arriving neutrinos, being important the fake events coming from the CC1π background. A precise knowledge of cross sections is a prerequisite in order to make simulations in event generators to substract the fake ones from the QE countings, and in this contribution we analyze the different nuclear effects on the CC1π channel. Our calculations also can be extended for the NC case.

  10. Hydrostatic pressure effect on photoionization cross section of a trion in quantum dots

    NASA Astrophysics Data System (ADS)

    Xie, Wenfang

    2013-11-01

    It is known experimentally that stable charged excitons can exist in low-dimensional semiconductor nanostructures. Much less is known about the properties of such charged-exciton complexes since three-body problems are very difficult to solve, even numerically. Here, we use the matrix diagonalization method and compact-density approach to investigate the charged excitons in a two-dimensional parabolic quantum dot. With typical semiconducting GaAs based materials, the photoionization cross section has been examined based on the computed energies and wave functions. We find that the photoionization cross section of charged excitons is strongly affected by the confinement frequency, hydrostatic pressure and temperature of QDs. Our results also show that the photoionization cross section of a negatively charged exciton is larger than that of a positively charged exciton.

  11. Diaphragm opening effects on shock wave formation and acceleration in a rectangular cross section channel

    NASA Astrophysics Data System (ADS)

    Pakdaman, S. A.; Garcia, M.; Teh, E.; Lincoln, D.; Trivedi, M.; Alves, M.; Johansen, C.

    2016-11-01

    Shock wave formation and acceleration in a high-aspect ratio cross section shock tube were studied experimentally and numerically. The relative importance of geometric effects and diaphragm opening time on shock formation are assessed. The diaphragm opening time was controlled through the use of slit-type (fast opening time) and petal-type (slow opening time) diaphragms. A novel method of fabricating the petal-type diaphragms, which results in a consistent burst pressure and symmetric opening without fragmentation, is presented. High-speed schlieren photography was used to visualize the unsteady propagation of the lead shock wave and trailing gas dynamic structures. Surface-mounted pressure sensors were used to capture the spatial and temporal development of the pressure field. Unsteady Reynolds-Averaged Navier-Stokes simulation predictions using the shear-stress-transport turbulence model are compared to the experimental data. Simulation results are used to explain the presence of high-frequency pressure oscillations observed experimentally in the driver section as well as the cause of the initial acceleration and subsequent rapid decay of shock velocity measured along the top and bottom channel surfaces. A one-dimensional theoretical model predicting the effect of the finite opening time of the diaphragm on the rate of driver depressurization and shock acceleration is proposed. The model removes the large amount of empiricism that accompanies existing models published in the literature. Model accuracy is assessed through comparisons with experiments and simulations. Limitations of and potential improvements in the model are discussed.

  12. Deformation effect on total reaction cross sections for neutron-rich Ne isotopes

    SciTech Connect

    Minomo, Kosho; Sumi, Takenori; Ogata, Kazuyuki; Shimizu, Yoshifumi R.; Yahiro, Masanobu; Kimura, Masaaki

    2011-09-15

    The isotope dependence of measured reaction cross sections in the scattering of {sup 28-32}Ne isotopes from a {sup 12}C target at 240 MeV/nucleon is analyzed by the double-folding model with the Melbourne g matrix. The density of the projectile is calculated by the mean-field model with the deformed Woods-Saxon potential. The deformation is evaluated by antisymmetrized molecular dynamics. The deformation of the projectile enhances calculated reaction cross sections to the measured values.

  13. Medium effects in K+ nucleus interaction from consistent analysis of integral and differential cross sections

    NASA Astrophysics Data System (ADS)

    Friedman, E.; Gal, A.; Mareš, J.

    1997-02-01

    Self-consistency in the analysis of transmission measurements for K+ on several nuclei in the momentum range of 500-700 MeV/c is achieved with a `teff(ρ)ρ' potential and new results are derived for total cross sections. The imaginary part of the teff amplitude is found to increase linearly with the average nuclear density in excess of a threshold value of 0.088+/-0.004 fm-3. This phenomenological density dependence of the K+ nucleus optical potential also gives rise to good agreement with recent measurements of differential cross sections for elastic scattering of 715 MeV/c K+ by 6Li and C.

  14. Nondipole effects in the triply differential cross section for double photoionization of He

    SciTech Connect

    Istomin, Andrei Y.; Starace, Anthony F.; Manakov, N.L.; Meremianin, A.V.

    2005-05-15

    Lowest-order nondipole effects are studied systematically in double photoionization (DPI) of the He atom. Ab initio parametrizations of the quadrupole transition amplitude for DPI from the {sup 1}S{sub 0} state are presented in terms of the exact two-electron radial matrix elements. Analytic expressions for these matrix elements within lowest-order perturbation theory (LOPT) in the interelectron interaction are also given. The corresponding parametrizations for the dipole-quadrupole triply differential cross section (TDCS) are presented for the case of an elliptically polarized photon. A general analysis of retardation-induced asymmetries of the TDCS including the circular dichroism effect at equal energy sharing is presented. Numerical LOPT estimates of nondipole asymmetries in photoelectron angular distributions for the cases of linear and circular polarization and of the circular dichroism effect at equal energy sharing are presented. We find that experimental observation of nondipole effects at excess energies of the order of tens to hundreds of eV should be feasible in TDCS measurements. Our numerical results exhibit a nondipole forward-backward asymmetry in the TDCS for DPI of He at an excess energy of 450 eV that is in qualitative agreement with existing experimental data.

  15. Synergistic effects of geometry, inertia, and dynamic contact angle on wetting and dewetting of capillaries of varying cross sections.

    PubMed

    Wang, Qiuling; Graber, Ellen R; Wallach, Rony

    2013-04-15

    Understanding the role of geometry, inertia, and dynamic contact angle on wetting and dewetting of capillary tubes has theoretical and practical aspects alike. The specific and synergistic effects of these factors were studied theoretically using a mathematical model that includes inertial and dynamic contact angle terms. After validating the model for capillaries of uniform cross section, the model was extended to capillaries with sinusoidal modulations of the radius, since in practice, capillaries rarely have uniform cross-sections. The height of the meniscus during wetting and dewetting was significantly affected by the relations between the local slope of the capillary surface and the Young contact angle. Non-dimensional variables were defined using viscous effects and gravity as the scaling parameters. Simulations using the dimensionless model showed that the inertial and dynamic contact angle terms can be neglected for narrow capillaries of uniform cross-section but not for uniform, wide cross-section capillaries. Moreover, nonuniformity in cross-sectional area induced hysteresis, deceleration, blocking, and metastable equilibrium locations. An increase in contact angle further amplified the effect of geometry on wetting and dewetting processes. These results enable characterization and modeling of fluid retention and flow in porous structures that inherently consist of capillaries of varying cross section.

  16. Two-dimensional two-photon absorbing chromophores and solvent effects on their cross-sections

    NASA Astrophysics Data System (ADS)

    Zheng, Lixin; Jen, Alex K.

    2003-02-01

    A series of 2-dimensional two-photon absorbing chromophores and their 1-dimensional analogs were studied. The influence of the solvents on the linear absorption, photoluminescence and two-photon absorption cross-sections were also examined for these chromophores. The stoke's shift increase with increasing solvent polarity, that can be adequately described by Lippert equation. Two-photon absorption cross sections were measured with femtosecond pulses by the two-photon-induced fluorescence technique. It was observed that two-photon cross-sections were also strongly dependent on the solvents, however no simple correlation with solvent polarity was found in this study. Interestingly, a linear relationship was observed in these chromophores between the molar extinction coefficient and the two-photon cross section when plotted in log-log formats. Understanding of the relationship may provide a better insight of the two-photon absorption processes, and potentially will contribute to the design of highly efficient two-photon absorbing chromophores.

  17. The Effect of New Ozone Cross Sections Applied to SBUV and TOMS Retrievals

    NASA Technical Reports Server (NTRS)

    McPeters, Richard D.; Labow, Gordon J.

    2010-01-01

    The ozone cross sections as measured by Bass and Paur have been used for processing of SBUV and TOMS data since 1986. While these cross sections were a big improvement over those previously available, there were known minor problems with accuracy for wavelengths longward of 330 nm and with the temperature dependance. Today's requirements to separate stratospheric ozone from tropospheric ozone and for the derivation of minor species such as BrO and N02 place stringent new requirements on the accuracy needed. The ozone cross section measurements of Brion, Daumont, and Malicet (BDM) are being considered for use in UV-based ozone retrievals. They have much better resolution, an extended wavelength range, and a more consistent temperature dependance. Tests show that BDM retrievals exhibit lower retrieval residuals in the satellite data; i.e., they explain our measured atmospheric radiances more accurately. Total column ozone retrieved by the TOMS instruments is about 1.5% higher than before. Ozone profiles retrieved from SBUV using the new cross sections are lower in the upper stratosphere and higher in the lower stratosphere and troposphere.

  18. Binary-Encounter-Bethe ionisation cross sections for simulation of DNA damage by the direct effect of ionising radiation.

    PubMed

    Plante, I; Cucinotta, F A

    2015-09-01

    DNA damage is of crucial importance in the understanding of the effects of ionising radiation. To refine existing DNA damage models, an approach using the Binary-Encounter-Bethe (BEB) cross sections was developed. The differential cross sections for ionisation of the molecular orbitals of the DNA bases, sugars and phosphates are calculated using the electron binding energy, the mean kinetic energy and the occupancy number of each orbital as parameters. The resulting cross section has an analytic form which is quite convenient to use for Monte-Carlo codes that randomly sample the energy loss occurring during an ionisation event. We also describe an algorithm to simulate the interactions of electrons with DNA in the radiation transport code RITRACKS using the integrated BEB cross section for the bases, sugar and phosphates.

  19. Accurate Cross Sections for Microanalysis

    PubMed Central

    Rez, Peter

    2002-01-01

    To calculate the intensity of x-ray emission in electron beam microanalysis requires a knowledge of the energy distribution of the electrons in the solid, the energy variation of the ionization cross section of the relevant subshell, the fraction of ionizations events producing x rays of interest and the absorption coefficient of the x rays on the path to the detector. The theoretical predictions and experimental data available for ionization cross sections are limited mainly to K shells of a few elements. Results of systematic plane wave Born approximation calculations with exchange for K, L, and M shell ionization cross sections over the range of electron energies used in microanalysis are presented. Comparisons are made with experimental measurement for selected K shells and it is shown that the plane wave theory is not appropriate for overvoltages less than 2.5 V. PMID:27446747

  20. Effect of local buckling on hysteretic behavior of beam-column with circular cross-section

    SciTech Connect

    Ueda, Yukio; Murakawa, Hidekazu; Shaker, R.E.

    1994-12-31

    In this paper, the hysteretic behavior of beam-column member having circular cross-section under simultaneously acting constant compressive axial load and cyclic lateral load is investigated. Elasto-plastic large deformation analysis by means of Finite Element Method (FEM) is utilized in this research. An emphasis is placed on the effect of the axial compressive load and geometrical parameters on the deterioration of the ultimate strength, the stiffness and the energy-dissipation capacity. Also, effect of the tangent modulus in the strain hardening region and different hardening rules are discussed. From this study, it is found that, in the absence of the axial compressive load, no deterioration in the strength, the stiffness and the absorbed energy are observed in all investigated members having different geometries. Meanwhile, in the case of the presence of axial load, local buckling (locally accumulated deflection under cyclic loading) may be induced depending on the geometrical parameters, namely, diameter-to-thickness ratio D/t and slenderness parameter {lambda} as well as the value of axial load ratio. Such local buckling reduces the ultimate strength and the stiffness of the member. The strength and the stiffness of the member are improved with smaller values of D/t and {lambda} and larger tangent modulus in the strain hardening region of the material.

  1. Effects of hormonal contraception on systemic metabolism: cross-sectional and longitudinal evidence

    PubMed Central

    Wang, Qin; Würtz, Peter; Auro, Kirsi; Morin-Papunen, Laure; Kangas, Antti J; Soininen, Pasi; Tiainen, Mika; Tynkkynen, Tuulia; Joensuu, Anni; Havulinna, Aki S; Aalto, Kristiina; Salmi, Marko; Blankenberg, Stefan; Zeller, Tanja; Viikari, Jorma; Kähönen, Mika; Lehtimäki, Terho; Salomaa, Veikko; Jalkanen, Sirpa; Järvelin, Marjo-Riitta; Perola, Markus; Raitakari, Olli T; Lawlor, Debbie A; Kettunen, Johannes; Ala-Korpela, Mika

    2016-01-01

    Background: Hormonal contraception is commonly used worldwide, but its systemic effects across lipoprotein subclasses, fatty acids, circulating metabolites and cytokines remain poorly understood. Methods: A comprehensive molecular profile (75 metabolic measures and 37 cytokines) was measured for up to 5841 women (age range 24–49 years) from three population-based cohorts. Women using combined oral contraceptive pills (COCPs) or progestin-only contraceptives (POCs) were compared with those who did not use hormonal contraception. Metabolomics profiles were reassessed for 869 women after 6 years to uncover the metabolic effects of starting, stopping and persistently using hormonal contraception. Results: The comprehensive molecular profiling allowed multiple new findings on the metabolic associations with the use of COCPs. They were positively associated with lipoprotein subclasses, including all high-density lipoprotein (HDL) subclasses. The associations with fatty acids and amino acids were strong and variable in direction. COCP use was negatively associated with albumin and positively associated with creatinine and inflammatory markers, including glycoprotein acetyls and several growth factors and interleukins. Our findings also confirmed previous results e.g. for increased circulating triglycerides and HDL cholesterol. Starting COCPs caused similar metabolic changes to those observed cross-sectionally: the changes were maintained in consistent users and normalized in those who stopped using. In contrast, POCs were only weakly associated with metabolic and inflammatory markers. Results were consistent across all cohorts and for different COCP preparations and different types of POC delivery. Conclusions: Use of COCPs causes widespread metabolic and inflammatory effects. However, persistent use does not appear to accumulate the effects over time and the metabolic perturbations are reversed upon discontinuation. POCs have little effect on systemic metabolism and

  2. Neutrino cross-sections: Experiments

    SciTech Connect

    Sánchez, F.

    2015-07-15

    Neutrino-nucleus cross-sections are as of today the main source of systematic errors for oscillation experiments together with neutrino flux uncertainties. Despite recent experimental and theoretical developments, future experiments require even higher precisions in their search of CP violation. We will review the experimental status and explore possible future developments required by next generation of experiments.

  3. Photoneutron cross sections for Au

    SciTech Connect

    Itoh, O.; Utsunomiya, H.; Akimune, H.; Yamagata, T.; Kondo, T.; Kamata, M.; Toyokawa, H.; Harada, H.; Kitatani, F.; Goko, S.; Nair, C.; Lui, Y.-W.

    2011-10-28

    Photoneutron cross sections were measured for Au in the entire energy range of the ({gamma},n) channel based on a direct neutron-counting technique with quasimonochromatic {gamma} rays produced in inverse Compton-scattering of laser photons with relativistic electrons. We present results of the measurement in comparison with the past data.

  4. Effective Potential Energies and Transport Cross Sections for Interactions of Hydrogen and Nitrogen

    NASA Technical Reports Server (NTRS)

    Stallcop, James R.; Partridge, Harry; Levin, Eugene; Arnold, James R. (Technical Monitor)

    2000-01-01

    The interaction energies for N2-He and N2-H2 are calculated by accurate ab initio methods. The virial coefficient and differential scattering cross section for N2-H2 are calculated; the theoretical results are compared with experimental data. The transport collision integrals for N2-H2 and N2-N2 interactions are calculated and tabulated; the results yield transport coefficients that compare well with measured data. Transport coefficients are found to be determined accurately from the interaction energies for a specific configuration of the molecule formed from the interaction partners. Comparisons with results of measurement and accurate calculations demonstrate that the transport properties of complex molecular interactions can be determined rapidly and fairly accurately from the interaction energies of simpler system using combination rules for the short-range parameters of effective interaction energies and the coefficients for the long-range forces. The coefficients for a two-parameter temperature expansion of diffusion and viscosity are tabulated for a realistic universal potential energy that is based primarily on the results of very accurate calculations of the He-He interaction energy.

  5. Denervation and castration effects on the cross-sectional area of pubococcygeus muscle fibers in male rats.

    PubMed

    Alvarado, Mayvi; Lara-García, Miguel; Cuevas, Estela; Berbel, Pere; Pacheco, Pablo

    2013-10-01

    The number of fibers in skeletal muscles changes little through life; however, the cross-sectional area of its fibers is modified as result of denervation and in some muscles by castration. The pubococcygeus muscle (Pcm) participates in micturition and ejaculatory processes and its fibers cross-sectional area is reduced in castrated rats, but denervation effects remained unknown. Here, we used a model in which unilateral denervation of this muscle in gonadally intact and castrated male rats, allowed us to explore the neural and gonadal hormone effects on the cross-sectional area of its fibers. Denervation significantly reduced the mean cross-sectional area values; likewise, the percentage distribution of its fibers. We found that castration had a greater effect than denervation. Castration resulted in a lack of fibers from 2,000 to 3,999 μm(2) , while in denervation it was from 2,500 to 3,999 μm(2) . It was interpreted that the castration effect was due to a lack of the direct gonadal hormone effect on muscle fibers, and to a reduction of the indirect hormonal action in its neuromuscular complex. In denervated Pcm of gonadally intact animals these effects were present; however, in denervated but castrated animals these were absent. Thus, combined surgeries resulted in the lowest mean cross-sectional area values with a restricted fiber distribution from 500 to 1,499 μm(2) . In conclusion, the study in this important muscle showed that cross-sectional area of its fibers depends on neural and direct/indirect gonadal hormone effects.

  6. Effect of cross-sectional buckling on the behavior of ACS support columns

    SciTech Connect

    Kennedy, J.M.; Belytschko, T.B.

    1983-01-01

    These analyses of the performance of the support columns for the above-core structures (ACS) have two principal aims: (1) to predict the forces exerted by the column in a hypothetical core-disruptive accident (HCDA) so that the motion of the ACS can be predicted in a coupled fluid-structure analysis, (2) to provide the strains and deformations of the columns so that situations which lead to complete failure of the support system can be identified. In previous studies, the columns were represented by beam elements so changes in the cross section could not be treated. While the columns in many designs are relatively thick-walled, scale-model tests performed at SRI indicate significant changes in the cross section. Therefore, models have been developed in which the portions of the column which undergo significant changes in cross section are modeled by plate elements. For the purpose of comparing the plate-beam models in the context of the loads expected in an HCDA, its predictions were compared to experimental results obtained in the SRI scale model tests. The solutions were obtained by the code SAFE/RAS; a new plate element was added to that program to perform these studies.

  7. Effectiveness Measures for Cross-Sectional Studies: A Comparison of Value-Added Models and Contextualised Attainment Models

    ERIC Educational Resources Information Center

    Lenkeit, Jenny

    2013-01-01

    Educational effectiveness research often appeals to "value-added models (VAM)" to gauge the impact of schooling on student learning net of the effect of student background variables. A huge amount of cross-sectional studies do not, however, meet VAM's requirement for longitudinal data. "Contextualised attainment models (CAM)"…

  8. The effect of scaling physiological cross-sectional area on musculoskeletal model predictions.

    PubMed

    Bolsterlee, Bart; Vardy, Alistair N; van der Helm, Frans C T; Veeger, H E J DirkJan

    2015-07-16

    Personalisation of model parameters is likely to improve biomechanical model predictions and could allow models to be used for subject- or patient-specific applications. This study evaluates the effect of personalising physiological cross-sectional areas (PCSA) in a large-scale musculoskeletal model of the upper extremity. Muscle volumes obtained from MRI were used to scale PCSAs of five subjects, for whom the maximum forces they could exert in six different directions on a handle held by the hand were also recorded. The effect of PCSA scaling was evaluated by calculating the lowest maximum muscle stress (σmax, a constant for human skeletal muscle) required by the model to reproduce these forces. When the original cadaver-based PCSA-values were used, strongly different between-subject σmax-values were found (σmax=106.1±39.9 N cm(-2)). A relatively simple, uniform scaling routine reduced this variation substantially (σmax=69.4±9.4 N cm(-2)) and led to similar results to when a more detailed, muscle-specific scaling routine was used (σmax=71.2±10.8 N cm(-2)). Using subject-specific PCSA values to simulate an shoulder abduction task changed muscle force predictions for the subscapularis and the pectoralis major on average by 33% and 21%, respectively, but was <10% for all other muscles. The glenohumeral (GH) joint contact force changed less than 1.5% as a result of scaling. We conclude that individualisation of the model's strength can most easily be done by scaling PCSA with a single factor that can be derived from muscle volume data or, alternatively, from maximum force measurements. However, since PCSA scaling only marginally changed muscle and joint contact force predictions for submaximal tasks, the need for PCSA scaling remains debatable.

  9. Evidence for the healthy immigrant effect in older Chinese immigrants: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Previous work has found that first-generation immigrants to developed nations tend to have better health than individuals born in the host country. We examined the evidence for the healthy immigrant effect and convergence of health status between Chinese immigrants (n = 147) and U.S. born whites (n = 167) participating in the cross-sectional Community Assessment of Freeway Exposure and Health study and residing in the same neighborhoods. Methods We used bivariate and multivariate models to compare disease prevalence and clinical biomarkers. Results Despite an older average age and lower socioeconomic status, Chinese immigrants were less likely to have asthma (OR = 0.20, 95% CI = 0.09–0.48) or cardiovascular disease (OR = 0.44, 95% CI = 0.20–0.94), had lower body mass index (BMI), lower inflammation biomarker levels, lower average sex-adjusted low-density lipoprotein (LDL) cholesterol, and higher average sex-adjusted high-density lipoprotein (HDL) cholesterol. However, there was no significant difference in the prevalence of diabetes or hypertension. Duration of time in the U.S. was related to cardiovascular disease and asthma but was not associated with diabetes, hypertension, BMI, HDL cholesterol, LDL cholesterol, socioeconomic status, or health behaviors. Conclusions The lower CVD and asthma prevalence among the Chinese immigrants may be partially attributed to healthier diets, more physical activity, lower BMI, and less exposure to cigarette smoke. First generation immigrant status may be protective even after about two decades. PMID:24928348

  10. Health effects of family size: cross sectional survey in Chinese adolescents

    PubMed Central

    Hesketh, T; Qu, J; Tomkins, A

    2003-01-01

    Aims: To determine whether only children differ in terms of morbidity, nutritional status, risk behaviours, and utilisation of health services from children with siblings, in China. Methods: A cross sectional survey was carried out using self completion questionnaires, anthropometry, and haemoglobin measurement in middle schools (predominant age 12–16 years) in three distinct socioeconomic areas of Zhejiang province, eastern China. Results: Data were obtained for 4197 participants. No significant differences were found between only children and those with siblings for some key indicators: underweight 19% v 18%, suicide ideation 14% v 14%, and ever smoking 17% v 15%. Only children were more likely to be overweight (4.8% v 1.5%), and to have attended a doctor (71% v 63%) or dentist (17% v 10%) in the past year. Sibling children are significantly more likely to be anaemic (42% v 32%) and to admit to depression (41% v 21%) or anxiety (45% v 37%). However, after adjusting for area, sex, and parental education levels only two differences remained: sibling children are more likely to be bullied (OR 1.5, 1.1–2.0; p = 0.006) and are less likely to confide in parents (OR 0.6, 0.3–0.8, p = 0.009). There were no significant differences in the key parameters between first and second born children. Conclusions: We found no detrimental effects of being an only child using the indicators measured. Being an only child may confer some benefits, particularly in terms of socialisation. PMID:12765907

  11. Respiratory effects associated with wood fuel use: a cross-sectional biomarker study among adolescents.

    PubMed

    Van Miert, Erik; Sardella, Antonia; Nickmilder, Marc; Bernard, Alfred

    2012-04-01

    The use of wood as heating and cooking fuel can result in elevated levels of indoor air pollution, but to what extent this is related to respiratory diseases and allergies is still inconclusive. Here, we report a cross-sectional study among 744 school adolescents (median age 15 years) using as main outcomes respiratory symptoms and diseases, exhaled nitric oxide, total and aeroallergen-specific IgE in serum, and two epithelial biomarkers in nasal lavage fluid (NALF) or serum, that is, Clara cell protein (CC16) and surfactant-associated protein D (SPD). Information about the wood fuel use and potential confounders was collected via a personal interview of the adolescent and a questionnaire filled out by the parents. Two approaches were used to limit the possible influence of confounders, that is, multivariate analysis using the complete study population or pairwise analysis of matched sub-populations obtained using an automated procedure. Wood fuel use was associated with a decrease of CC16 and an increase of SPD in serum, which resulted in a decreased serum CC16/SPD ratio (median -9%, P = 0.001). No consistent differences were observed for the biomarkers measured in exhaled breath or NALF. Wood fuel use was also associated with increased odds for asthma [odds ratio (OR) 2.2, 95% CI: 1.1-4.4, P = 0.02], hay fever (OR = 2.4, 95% CI: 1.4-4.3, P = 0.002), and sensitization against pollen allergens (OR = 2.1, 95% CI: 1.3-3.4, P = 0.002). The risks of respiratory tract infections, self-reported symptoms, and sensitization against house-dust mite were not increased by wood fuel use. The increased risks of asthma, hay fever and aeroallergen sensitization, and the changes of lung-specific biomarkers consistently pointed towards respiratory effects associated with the use of wood fuel.

  12. Determination of the effective inelastic p anti-p cross-section for the D0 Run II luminosity measurement

    SciTech Connect

    Edwards, T.; Yacoob, S.; Andeen, T.; Begel, M.; Casey, B.C.K.; Partridge, R.; Schellman, H.; Sznajder, A.; /Rio de Janeiro State U.

    2004-11-01

    The authors determine the effective inelastic p{bar p} cross-section into the D0 Luminosity Monitor for all run periods prior to September 2004. This number is used to relate the measured inelastic collision rate to the delivered luminosity. The key ingredients are the inelastic p{bar p} cross-section, the Luminosity Monitor efficiency, and the modeling of kinematic distributions for various inelastic processes used to determine the detector acceptance. The resulting value is {sigma}{sub p{bar p},eff} = 46 {+-} 3 mb.

  13. EFFECTS OF NITROGEN PHOTOABSORPTION CROSS SECTION RESOLUTION ON MINOR SPECIES VERTICAL PROFILES IN TITAN’S UPPER ATMOSPHERE

    SciTech Connect

    Luspay-Kuti, A.; Mandt, K. E.; Greathouse, T. K.; Plessis, S.

    2015-03-01

    The significant variations in both measured and modeled densities of minor species in Titan’s atmosphere call for the evaluation of possible influencing factors in photochemical modeling. The effect of nitrogen photoabsorption cross section selection on the modeled vertical profiles of minor species is analyzed here, with particular focus on C{sub 2}H{sub 6} and HCN. Our results show a clear impact of cross sections used on all neutral and ion species studied. Affected species include neutrals and ions that are not primary photochemical products, including species that do not even contain nitrogen. The results indicate that photochemical models that employ low-resolution cross sections may significantly miscalculate the vertical profiles of minor species. Such differences are expected to have important implications for Titan’s overall atmospheric structure and chemistry.

  14. Effects of Instructional Strategies Using Cross Sections on the Recognition of Anatomical Structures in Correlated CT and MR Images

    ERIC Educational Resources Information Center

    Khalil, Mohammed K.; Paas, Fred; Johnson, Tristan E.; Su, Yung K.; Payer, Andrew F.

    2008-01-01

    This research is an effort to best utilize the interactive anatomical images for instructional purposes based on cognitive load theory. Three studies explored the differential effects of three computer-based instructional strategies that use anatomical cross-sections to enhance the interpretation of radiological images. These strategies include:…

  15. Systematic study of deformation effects on fusion cross-sections using various proximity potentials

    NASA Astrophysics Data System (ADS)

    Rajbongshi, Tapan; Kalita, Kushal

    2014-06-01

    The influence of static quadrupole and hexadecapole (positive & negative) deformation of targets are studied using eleven different versions of nuclear potentials. The height and position of the interaction barrier for the reactions induced by spherical projectile (16O) on the deformed targets such as 166Er, 154Sm and 176Yb have been estimated. It is found that the nucleus-nucleus potential strongly depends on the value of the deformation parameters and orientation of the target. The experimental fusion cross-section of the reactions 16O + 176Yb, 16O +166Er and 16O +154Sm are investigated by applyingWong's formula using various parameterizations of the proximity potential as well as an assessment of the results of a multi-dimensional barrier penetration model (BPM). The fusion cross-sections by Prox 77, Prox 88, Prox 00, Prox 00DP, Denisov DP, Bass 80, CW 76 and AW 95 potentials are found to be better than the rest in comparison to experimental data.

  16. Geometry effects on magnetization dynamics in circular cross-section wires

    SciTech Connect

    Sturma, M.; Toussaint, J.-C. E-mail: daria.gusakova@cea.fr; Gusakova, D. E-mail: daria.gusakova@cea.fr

    2015-06-28

    Three-dimensional magnetic memory design based on circular-cross section nanowires with modulated diameter is the emerging field of spintronics. The consequences of the mutual interaction between electron spins and local magnetic moments in such non-trivial geometries are still open to debate. This paper describes the theoretical study of domain wall dynamics within such wires subjected to spin polarized current. We used our home-made finite element software to characterize the variety of domain wall dynamical regimes observed for different constriction to wire diameter ratios d/D. Also, we studied how sizeable geometry irregularities modify the internal micromagnetic configuration and the electron spin spatial distribution in the system, the geometrical reasons underlying the additional contribution to the system's nonadiabaticity, and the specific domain wall width oscillations inherent to fully three-dimensional systems.

  17. Tunable electromechanical coupling of a carbon nanotube-reinforced variable cross-section nanoswitch with a piezoelectric effect

    NASA Astrophysics Data System (ADS)

    Yang, W. D.; Li, Y. D.; Wang, X.

    2016-08-01

    An analytical method is presented to investigate the pull-in instability of a carbon nanotube (CNT)-reinforced variable cross-section nanoswitch with a piezoelectric effect. Governing equations with variable coefficients are derived based on the nonlocal beam model with geometrical nonlinearity and are solved using the shooting method. All the nonlinear effects of the piezoelectric voltage, van der Waals force, Casimir force, CNT volume fraction, nonlocal parameters and width ratio on the pull-in instability are investigated. The pull-in electrostatic voltage increases with the increment of nonlocal parameters, which exhibits the significant scale-dependent behavior of nanostructures. The results show that the variable cross-section improves the flexural rigidity of the cantilever-type nanoswitch effectively, and that the piezoelectric effect of the piezoelectric layer is utilized to control the electrostatic force induced by the voltage exerted on the elastic layer, owing to piezoelectric materials’ advantages of rapid response, light weight and low energy consumption.

  18. The effective absorption cross-section of thermal neutrons in a medium containing strongly or weakly absorbing centres

    NASA Astrophysics Data System (ADS)

    Drozdowicz, Krzysztof; Gabańska, Barbara; Igielski, Andrzej; Krynicka, Ewa; Woźnicka, Urszula

    2003-06-01

    The structure of a heterogeneous system influences diffusion of thermal neutrons. The thermal-neutron absorption in grained media is considered in the paper. A simple theory is presented for a two-component medium treated as grains embedded in the matrix or as a system built of two types of grains (of strongly differing absorption cross-sections). A grain parameter is defined as the ratio of the effective macroscopic absorption cross-section of the heterogeneous medium to the absorption cross-section of the corresponding homogeneous medium (consisting of the same components in the same proportions). The grain parameter depends on the ratio of the absorption cross-sections and contributions of the components and on the size of grains. The theoretical approach has been verified in experiments on prepared dedicated models which have kept required geometrical and physical conditions (silver grains distributed regularly in Plexiglas). The effective absorption cross-sections have been measured and compared with the results of calculations. A very good agreement has been observed. In certain cases the differences between the absorption in the heterogeneous and homogeneous media are very significant. A validity of an extension of the theoretical model on natural, two-component, heterogeneous mixtures has been tested experimentally. Aqueous solutions of boric acid have been used as the strongly absorbing component. Fine- and coarse-grained pure silicon has been used as the second component with well-defined thermal-neutron parameters. Small and large grains of diabase have been used as the second natural component. The theoretical predictions have been confirmed in these experiments.

  19. Cross sections for 14-eV e-H{sub 2} resonant collisions: Isotope effect in dissociative electron attachment

    SciTech Connect

    Celiberto, R.; Janev, R. K.; Wadehra, J. M.; Laricchiuta, A.

    2011-07-15

    The process of dissociative attachment of electrons to molecular hydrogen and its isotopes in the energy range at approximately 14 eV is investigated. The dissociative electron attachment cross sections for all six hydrogen isotopes are calculated over an extended range of electron energies using the local complex potential model with the excited Rydberg {sup 2}{Sigma}{sub g}{sup +} electronic state of H{sub 2}{sup -} acting as the intermediate resonant state. A significant isotope effect in theoretical electron attachment cross sections is observed, in agreement with previous predictions and experimental observations. A two-parameter analytic expression for the cross section is derived from the theory that fits accurately the numerically calculated cross sections for all isotopes. Similarly, an analytic mass-scaling relation is derived from the theory that accurately reproduces the numerically calculated rate coefficients for all isotopes in the 0.1-1000 eV temperature range by using the rate coefficient for the H{sub 2} isotope only. The latter is represented by an analytic fit expression with two parameters only.

  20. Effect of cross-section interpolated bathymetry on 2D hydrodynamic results in a large river system

    NASA Astrophysics Data System (ADS)

    Conner, J.; Tonina, D.; Welcker, C.

    2011-12-01

    Two-dimensional (2D) hydrodynamic models have been used for many river research projects including flood analysis, aquatic habitat evaluation and sediment transport studies. River topography has a strong influence on flow patterns and a dominant effect on the resulting hydraulic conditions. Thus, it is important that adequate topographic data be collected so accurate DEMs can be developed in order to create 2D hydrodynamic models that correctly represent hydraulic conditions. Many techniques and methods have been used to acquire bathymetry data, from traditional survey methods, using sonar equipment combined with GPS and more recently the use of Experimental Advance Airborne Research LiDAR (EAARL). Multi-beam sonar and EAARL provide rapid collection of bathymetry data that can be used to create high resolution three dimensional surfaces. However, these systems do not work in all river conditions requiring other methods of data collection. One method that has been employed is to collect cross section data and interpolate a surface between the cross sections. This method is a valuable technique, because cross sections can be surveyed with traditional survey equipment for wadeable streams or with a variety of watercraft. In this study, we investigated the effect cross section spacing has on developing the streambed topography and flow properties for 2D modeling. To evaluate the resulting errors that can be expected, we compared 2D model results of two reaches of the Snake River (Idaho, USA) that had complete bathymetry, with 2D model results of the same river reaches, but were developed by interpolating bathymetry between transects. We chose reaches with simple and complex channel morphologies to test the variability of error that may be expected for natural channels that fall between these types. We evaluated the error created on sediment transport by size class and habitat quality for fish species. The preliminary results indicate that increasing the cross section

  1. Electron-Impact Ionization Cross Section Database

    National Institute of Standards and Technology Data Gateway

    SRD 107 Electron-Impact Ionization Cross Section Database (Web, free access)   This is a database primarily of total ionization cross sections of molecules by electron impact. The database also includes cross sections for a small number of atoms and energy distributions of ejected electrons for H, He, and H2. The cross sections were calculated using the Binary-Encounter-Bethe (BEB) model, which combines the Mott cross section with the high-incident energy behavior of the Bethe cross section. Selected experimental data are included.

  2. Effect of diameter of nanoparticles and capture cross-section library on macroscopic dose enhancement in boron neutron capture therapy

    PubMed Central

    Farhood, Bagher

    2014-01-01

    Purpose The aim of this study is evaluation of the effect of diameter of 10B nanoparticles and various neutron capture cross-section libraries on macroscopic dose enhancement in boron neutron capture therapy (BNCT). Material and methods MCNPX Monte Carlo code was used for simulation of a 252Cf source, a soft tissue phantom and a tumor containing 10B nanoparticles. Using 252Cf as a neutron source, macroscopic dose enhancement factor (MDEF) and total dose rate in tumor in the presence of 100, 200, and 500 ppm of 10B nanoparticles with 25 nm, 50 nm, and 100 nm diameters were calculated. Additionally, the effect of ENDF, JEFF, JENDL, and CENDL neutron capture cross-section libraries on MDEF was evaluated. Results There is not a linear relationship between the average MDEF value and nanoparticles’ diameter but the average MDEF grows with increased concentration of 10B nanoparticles. There is an increasing trend for average MDEF with the tumor distance. The average MDEF values were obtained the same for various neutron capture cross-section libraries. The maximum and minimum doses that effect on the total dose in tumor were neutron and secondary photon doses, respectively. Furthermore, the boron capture related dose component reduced in some extent with increase of diameter of 10B nanoparticles. Conclusions Based on the results of this study, it can be concluded that from physical point of view, various nanoparticle diameters have no dominant effect on average MDEF value in tumor. Furthermore, it is concluded that various neutron capture cross-section libraries are resulted to the same macroscopic dose enhancements. However, it is predicted that taking into account the biological effects for various nanoparticle diameters will result in different dose enhancements. PMID:25834582

  3. The Effective Cross-section and Imaging Property of a Lensing-galaxy: Singular Isothermal Sphere with External Shear

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Wook; Kim, S. J.; Lee, D.

    2013-07-01

    We present extensive numerical studies on the imaging and caustic properties of the singular isothermal sphere (SIS) with including a wide range of external shear being even more than 1.0 (ranging from 0.0 to 2.0). Using a direct inverse mapping formula of lens system (Lee 2003), various imaging properties are investigated as a function of the shear: image separation, total or individual magnifications depending on image multiplicity (i.e., 2-, 3-, & 4-images), flux ratios of double-image, and lensing cross sections. These properties are numerically investigated for the both realms of shear in a low (i.e., γ < 1.0), and a high (i.e., γ >1.0) magnitude. To investigate the frequency of 2 (double)- and 4 (quad)-image lensing systems, we systematically analyze the effective-lensing cross-sections (see Section 3) of double-lensing and quad-lensing systems based on the power-law luminosity function of flat-spectrum radio sources obtained by Jodrell-VLA Astrometric Survey (JAVAS) and Cosmic Lens ALL-Sky Survey (CLASS). Taking into account the external shear and the magnification bias effect with survey selection bias, our analysis on the effective-lensing cross-sections shows a strong dependency of both the shear and the survey selection bias, especially for the double-lensing. It thus turns out that the variation of effective-lensing cross-section of 2-image lensing systems is very sensitive compared with the 4-image lensing systems. Therefore, we find that the observed high quads-to-doubles ratios (i.e., JAVAS & CLASS: 50% ~ 70%) should be understandable in terms of the effective shear of 0.16 ~ 0.18, which is approximately a half of the previous estimates on the corresponding shear around 0.3. Thus, our numerical analysis may provide a solution for the long standing problem of high quads-to-doubles ratio observed n gravitational lens surveys. Estimated ratios of the quads-to-doubles and the triples-to-doubles are also presented. The inverse mapping formula of the SIS

  4. Total cross sections for +/-atom collisions

    NASA Astrophysics Data System (ADS)

    Gien, T. T.

    1987-03-01

    The total cross sections for electron and positron scatterings by lithium, sodium, and potassium in the intermediate energy range from 40 to 1000 eV are calculated using the modified Glauber and second Born approximations. A model potential approach is developed to enable an exact inclusion of the core-interaction effects. Within this approach, the positron cross sections are predicted to be somewhat smaller than those of electron scattering. Calculations have also been performed with the consideration of the inert-core and frozen-core assumption and the use of the Clementi wave function to represent the target electrons. Comparison to existing experimental data is made.

  5. Modeling the Effects of Solar Cell Attitude Distribution on Optical Cross Section for Solar Panel Simulations

    NASA Astrophysics Data System (ADS)

    Feirstine, K.; Bush, K.; Crosher, C.; Klein, M.; Bowers, D.; Wellems, D.; Duggin, M.; Vaughn, L.

    2012-09-01

    The Air Force Research Laboratory (AFRL) Time-domain Analysis Simulation for Advanced Tracking (TASAT) was used to explore the variation of Optical Cross Section (OCS) with glint angle for a solar panel with different solar cell attitude distribution statistics. Simulations were conducted using a 3D model of a solar panel with various solar cell tip and tilt distribution statistics. Modeling a solar panel as a single sheet of "solar cell" material is not appropriate for OCS glint studies. However, modeling each individual solar cell on the panel, the tips and tilts of which come from a distribution of specified statistics (distribution type, mean, and standard deviation), accurately captures the solar panel OCS with glint angle. The objective of the simulations was to vary the glint measurement angle about the maximum glint position of the solar panel and observe the variations in OCS with angle for a bi-static illumination condition. OCS was calculated relative to the simulated scattering of a Spectralon material in the glint orientation. Results show the importance of solar cell attitude distribution statistics in modeling the OCS observed for a solar panel.

  6. Cross Sections From Scalar Field Theory

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Dick, Frank; Norman, Ryan B.; Nasto, Rachel

    2008-01-01

    A one pion exchange scalar model is used to calculate differential and total cross sections for pion production through nucleon- nucleon collisions. The collisions involve intermediate delta particle production and decay to nucleons and a pion. The model provides the basic theoretical framework for scalar field theory and can be applied to particle production processes where the effects of spin can be neglected.

  7. Neutron cross sections: Book of curves

    SciTech Connect

    McLane, V.; Dunford, C.L.; Rose, P.F.

    1988-01-01

    Neuton Cross Sections: Book of Curves represents the fourth edition of what was previously known as BNL-325, Neutron Cross Sections, Volume 2, CURVES. Data is presented only for (i.e., intergrated) reaction cross sections (and related fission parameters) as a function of incident-neutron energy for the energy range 0.01 eV to 200 MeV. For the first time, isometric state production cross sections have been included. 11 refs., 4 figs.

  8. Photoproduction total cross section and shower development

    NASA Astrophysics Data System (ADS)

    Cornet, F.; García Canal, C. A.; Grau, A.; Pancheri, G.; Sciutto, S. J.

    2015-12-01

    The total photoproduction cross section at ultrahigh energies is obtained using a model based on QCD minijets and soft-gluon resummation and the ansatz that infrared gluons limit the rise of total cross sections. This cross section is introduced into the Monte Carlo system AIRES to simulate extended air showers initiated by cosmic ray photons. The impact of the new photoproduction cross section on common shower observables, especially those related to muon production, is compared with previous results.

  9. Effect of momentum dependent interactions and nucleonic cross-section on directed flow (v{sub 1})

    SciTech Connect

    Jain, Anupriya; Vinayak, Karan Singh; Kumar, Suneel

    2013-07-15

    The descriptive analysis for the effect of momentum dependent interactions and nucleonic cross-section (isospin dependent and isospin-independent) on the neutron–proton directed flow (v{sub 1}), within the framework of the isospin dependent quantum molecular dynamics model is presented. Our study shows that, the directed flow of both neutrons and protons is affected by the momentum dependence of nuclear equation of state and the isospin dependence of nucleon–nucleon cross-section. A soft momentum dependent (SM) equation of state is found to be more compatible with the experimental data. -- Highlights: •Role of rapidity cut on transverse flow has been explored. •p{sub t} differential flow for protons and neutrons has been studied. •Role of MDI on directed flow has been studied.

  10. X-ray-induced electron cascades in dielectrics modeled with XCASCADE code: effect of impact ionization cross sections

    NASA Astrophysics Data System (ADS)

    Medvedev, Nikita A.

    2015-05-01

    Characterization of a free-electron laser (FEL) pulse can be done with a pump-probe scheme, using an FEL pump and a visible light probe on an optically transparent solid-state target. With such experimental scheme, pulse duration can be monitored on a shot-to-shot basis. It relies on the changes in optical properties induced by the FEL excitation of electrons. Here we analyze effects of different cross sections used in the modeling of electron kinetics. XCASCADE, a Monte Carlo toolkit for modeling x-ray-induced electron cascades (N. Medvedev, Appl. Phys. B 118 (2015) 417), is used for this purpose. Two different cross sections are compared: atomic BEB model vs complex-dielectric function formalism that accounts for collective effects in solids. It is shown that for photon and electron energies above a few tens of eV, the both models coincide very closely. For lower energies in the VUV regime, the difference in the cross sections become more significant, nevertheless producing qualitatively similar electron kinetics and increase in the density of excited electrons.

  11. Cross Sections: No. 1 Hold section at Fr 24 Looking ...

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

    Cross Sections: No. 1 Hold section at Fr 24 Looking Fwd, No 1 Hold Section at Fr 28 Looking Aft, No 2 Hold Section at Fr 48 Looking Aft, No 3 Hold Section at Fr 70 Looking Aft, No 4 Hold Section at Fr 90 Looking Aft - General John Pope, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  12. [Fast neutron cross section measurements

    SciTech Connect

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are clean'' and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its data production'' phase.

  13. Effect of shell drilling stiffness on response calculations of rectangular plates and tubes of rectangular cross-section under compression.

    SciTech Connect

    Gorman, Jhana; Hales, Jason Dean; Corona, Edmundo

    2010-05-01

    This report considers the calculation of the quasi-static nonlinear response of rectangular flat plates and tubes of rectangular cross-section subjected to compressive loads using quadrilateralshell finite element models. The principal objective is to assess the effect that the shell drilling stiffness parameter has on the calculated results. The calculated collapse load of elastic-plastic tubes of rectangular cross-section is of particular interest here. The drilling stiffness factor specifies the amount of artificial stiffness that is given to the shell element drilling Degree of freedom (rotation normal to the plane of the element). The element formulation has no stiffness for this degree of freedom, and this can lead to numerical difficulties. The results indicate that in the problems considered it is necessary to add a small amount of drilling tiffness to obtain converged results when using both implicit quasi-statics or explicit dynamics methods. The report concludes with a parametric study of the imperfection sensitivity of the calculated responses of the elastic-plastic tubes with rectangular cross-section.

  14. SNL RML recommended dosimetry cross section compendium

    SciTech Connect

    Griffin, P.J.; Kelly, J.G.; Luera, T.F.; VanDenburg, J.

    1993-11-01

    A compendium of dosimetry cross sections is presented for use in the characterization of fission reactor spectrum and fluence. The contents of this cross section library are based upon the ENDF/B-VI and IRDF-90 cross section libraries and are recommended as a replacement for the DOSCROS84 multigroup library that is widely used by the dosimetry community. Documentation is provided on the rationale for the choice of the cross sections selected for inclusion in this library and on the uncertainty and variation in cross sections presented by state-of-the-art evaluations.

  15. Cross Sections: No 6 Hold Section at Fr 178 Looking ...

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

    Cross Sections: No 6 Hold Section at Fr 178 Looking Fwd, No 7 Hold Section at No 154 Looking Fwd, No 7 Hold Section at Fr 195 Looking Fwd Showing Trans 194, No 7 Hold Section at Fr 198 Looking Fwd - General John Pope, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  16. Effect of wave function on the proton induced L XRP cross sections for {sub 62}Sm and {sub 74}W

    SciTech Connect

    Shehla,; Kaur, Rajnish; Kumar, Anil; Puri, Sanjiv

    2015-08-28

    The L{sub k}(k= 1, α, β, γ) X-ray production cross sections have been calculated for {sub 74}W and {sub 62}Sm at different incident proton energies ranging 1-5 MeV using theoretical data sets of different physical parameters, namely, the Li(i=1-3) sub-shell X-ray emission rates based on the Dirac-Fork (DF) model, the fluorescence and Coster Kronig yields based on the Dirac- Hartree-Slater (DHS) model and two sets the proton ionization cross sections based on the DHS model and the ECPSSR in order to assess the influence of the wave function on the XRP cross sections. The calculated cross sections have been compared with the measured cross sections reported in the recent compilation to check the reliability of the calculated values.

  17. Primary pressure standard based on piston-cylinder assemblies. Calculation of effective cross sectional area based on rarefied gas dynamics

    NASA Astrophysics Data System (ADS)

    Sharipov, Felix; Yang, Yuanchao; Ricker, Jacob E.; Hendricks, Jay H.

    2016-10-01

    Currently, the piston-cylinder assembly known as PG39 is used as a primary pressure standard at the National Institute of Standards and Technology (NIST) in the range of 20 kPa to 1 MPa with a standard uncertainty of 3× {{10}-6} as evaluated in 2006. An approximate model of gas flow through the crevice between the piston and sleeve contributed significantly to this uncertainty. The aim of this work is to revise the previous effective cross sectional area of PG39 and its uncertainty by carrying out more exact calculations that consider the effects of rarefied gas flow. The effective cross sectional area is completely determined by the pressure distribution in the crevice. Once the pressure distribution is known, the elastic deformations of both piston and sleeve are calculated by finite element analysis. Then, the pressure distribution is recalculated iteratively for the new crevice dimension. As a result, a new value of the effective area is obtained with a relative difference of 3× {{10}-6} from the previous one. Moreover, this approach allows us to reduce significantly the standard uncertainty related to the gas flow model so that the total uncertainty is decreased by a factor of three.

  18. Formulation and solution of the delayed gamma dose rate problem using the concept of effective delayed gamma production cross section

    SciTech Connect

    Liew, S.L.; Ku, L.P.

    1989-06-01

    With appropriate approximations, the delayed gamma dose rate problem can be formulated in terms of the effective delayed gamma production cross section. The coupled neutron-delayed-gamma transport equations then take the same form as the coupled neutron-prompt-gamma transport equations and they can, therefore, be solved directly in the same manner. This eliminates the need for the tedious and error prone flux coupling step in conventional calculations. Mathematical formulation and solution algorithms are derived. The advantages of this method are illustrated by an example of its application in the solution of a practical design problem. 62 refs., 10 figs., 1 tab.

  19. The effects of castration and hormone replacement on the cross-sectional area of pubococcygeus muscle fibers in the female rat.

    PubMed

    Lara-García, Miguel; Alvarado, Mayvi; Cuevas, Estela; Cortés-sol, Albertina; Domínguez, Andrés; Tovar, Anibal; Pacheco, Pablo

    2011-07-01

    In this study, we analyzed the effect of ovariectomy and gonadal hormone replacement on the cross-sectional area of pubococcygeus (Pcm) fibers. It was found that in comparison to intact animals, ovariectomized animals [for 2 or 6 weeks] had an increased cross-sectional area average in Pcm fibers. Ovariectomy also reduced the percentage of fibers with smaller cross-sectional area. In ovariectomized animals after 4 weeks of hormone replacement with an empty Silastic capsule or filled with testosterone propionate or dihydrotestosterone, significantly increased the cross-sectional area average and the percentage of fibers with larger size. However, 17β-estradiol but not estradiol benzoate treatment reduced the cross-sectional area average and increased the percentage of Pcm fibers with smaller size. Progesterone did not have an effect on the cross-sectional area of this muscle. We conclude that Pcm fibers of female rats are sensitive to gonadal hormones, and contrary to male castration, ovariectomy promotes an increase in their cross-sectional area. Also, we discuss according to other studies that an external mechanism which lies within the neuromuscular periphery could also participate in the modulatory hormonal effect on mass or muscle fiber size. Furthermore, in this process, estradiol is likely to regulate the fiber cross-sectional area growing produced by androgens.

  20. Vertically stabilized elongated cross-section tokamak

    DOEpatents

    Sheffield, George V.

    1977-01-01

    This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

  1. Absolute cross sections of compound nucleus reactions

    NASA Astrophysics Data System (ADS)

    Capurro, O. A.

    1993-11-01

    The program SEEF is a Fortran IV computer code for the extraction of absolute cross sections of compound nucleus reactions. When the evaporation residue is fed by its parents, only cumulative cross sections will be obtained from off-line gamma ray measurements. But, if one has the parent excitation function (experimental or calculated), this code will make it possible to determine absolute cross sections of any exit channel.

  2. Cross Sections for Electron Collisions with Acetylene

    NASA Astrophysics Data System (ADS)

    Song, Mi-Young; Yoon, Jung-Sik; Cho, Hyuck; Karwasz, Grzegorz P.; Kokoouline, Viatcheslav; Nakamura, Yoshiharu; Tennyson, Jonathan

    2017-03-01

    Cross section data are compiled from the literature for electron collisions with the acetylene (HCCH) molecule. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational and vibrational states, dissociation, ionization, and dissociative attachment. The data derived from swarm experiments are also considered. For each of these processes, the recommended values of the cross sections are presented. The literature has been surveyed through early 2016.

  3. Cross Sections for Electron Collisions with Methane

    SciTech Connect

    Song, Mi-Young Yoon, Jung-Sik; Cho, Hyuck; Itikawa, Yukikazu; Karwasz, Grzegorz P.; Kokoouline, Viatcheslav; Nakamura, Yoshiharu; Tennyson, Jonathan

    2015-06-15

    Cross section data are compiled from the literature for electron collisions with methane (CH{sub 4}) molecules. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational and vibrational states, dissociation, ionization, and dissociative attachment. The data derived from swarm experiments are also considered. For each of these processes, the recommended values of the cross sections are presented. The literature has been surveyed through early 2014.

  4. Proton Pair Production Cross Sections at BESIII

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaorong

    Using data samples collected with the BESIII detector at the BEPCII collider, the Born cross section of e + e - to pbar{p} at 12 center-of-mass energies from 2232.4 to 3671.0 MeV is provided. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal. In addition, the ratio of electric to magnetic form factors are extracted for the data samples with larger statistics. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30%. The |GE/GM| ratios are close to unity and consistent with BaBar results in the same q2 region.

  5. Universal Parameterization of Absorption Cross Sections

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.

    1997-01-01

    This paper presents a simple universal parameterization of total reaction cross sections for any system of colliding nuclei that is valid for the entire energy range from a few AMeV to a few AGeV. The universal picture presented here treats proton-nucleus collision as a special case of nucleus-nucleus collision, where the projectile has charge and mass number of one. The parameters are associated with the physics of the collision system. In general terms, Coulomb interaction modifies cross sections at lower energies, and the effects of Pauli blocking are important at higher energies. The agreement between the calculated and experimental data is better than all earlier published results.

  6. Quantitative estimates of the effects of cross section uncertainties on the derivation of GCR source composition. [Galactic Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Hinshaw, G. F.; Wiedenbeck, M. E.

    1983-01-01

    Cosmic-ray source abundance uncertainties, resulting from the cross-section uncertainties, are calculated for the elements carbon through nickel. A significant dominance of cross-section errors in the source abundance uncertainties is found for most of the elements considered, even with uncorrelated partial cross-section errors; much larger uncertainties than those reported previously are found for Ca, N, Na, Al, and S. Propagation errors are noted to preclude a significant determination of source abundances for F, Cl, and Mn. A need for an assessment of the existing cosmic-ray propagation models - especially the propagation cross-sections which they employ - is expressed, motivated by recent improvements in the resolution and statistical accuracy of observations.

  7. Pulse duration effects on laser-assisted electron transfer cross section for He2+ ions colliding with atomic hydrogen

    NASA Astrophysics Data System (ADS)

    Domínguez-Gutiérrez, Francisco Javier; Cabrera-Trujillo, Remigio

    2014-08-01

    We study the effect of the pulse duration for an ultra-fast and intense laser on the fundamental process of electron capture by analyzing the excitation probability into the n = 2 and n = 3 states when He2+ collides with atomic hydrogen in the 0.05-10 keV/amu energy range, a region of interest for diagnostic processes on plasma and fusion power reactors. We solve the time-dependent Schrödinger equation to calculate the electron capture probability by means of a finite-differences, as well as by an electron-nuclear dynamics approach. In particular, we study the effects of 1, 3, 6, and 10 fs laser pulses at FWHM, wavelength of 780 nm and intensity of 3.5 × 1012 W/cm2. We report good agreement for the laser-free state and total electron transfer cross-sections when compared to available theoretical and experimental data. The effect of the laser pulse on the electron capture probability as a function of the impact parameter is such that the charge exchange probability increases considerably in the impact parameter radial region with an increase in the amplitude oscillations and a phase shift on the Stückelberg oscillations. We find an increase on the total electron exchange cross-section for low projectile collision energy when compared to the laser-free case with a minimal effect at high collision energies. We find that the 1 fs laser pulse has a minimal effect, except for very low collision energies. Although in general, the longer the laser pulse, the larger the electron capture probability, at very low collision energies all pulse widths have an effect. For processes in the atto-second region, our findings suggest that to enhance the laser-assisted charge exchange, the best region for short pulses is at very low collision energies. We also find that the s and p state charge exchange cross section are equally affected. We provide a qualitative discussion of these findings.

  8. Effect of temperature-dependent cross sections on O4 slant column density estimation by a space-borne UV-visible hyperspectral sensor

    NASA Astrophysics Data System (ADS)

    Park, Sang Seo; Takemura, Toshihiko; Kim, Jhoon

    2017-03-01

    The sensitivities of oxygen dimer (O4) slant column densities (SCDs) were examined by applying temperature-dependent O4 cross sections using the radiative transfer model (RTM) calculation with the linearized pseudo-spherical vector discrete ordinate radiative transfer model. For the sensitivity study, we used a newly developed cross section database in place of the database used in the operational algorithm. Newly investigated O4 cross section databases for 203 K and 293 K were used for the radiance simulation by interpolating temperature for each atmospheric layer based on the vertical profile of standard atmosphere in the RTM. The effect of the temperature-dependent cross sections was a significant O4 SCD increase of 8.3% with dependence on satellite and solar viewing geometries. Furthermore, the O4 SCD generally increased by an estimated 3.9% based on the observation geometries of the Ozone Monitoring Instrument. For the long-term comparison, the O4 SCD estimated from the temperature-dependent cross sections corrects 20% of the total underestimation of O4 SCD between the observation and simulation. Although the surface pressure variation and background aerosol effect also correct the O4 SCD discrepancy, the effect of temperature-dependent cross sections was more important than the effects of surface pressure variation and background aerosols. Therefore, temperature dependence of the cross section in the RTM calculation is essential for the accurate simulation of O4 SCD.

  9. Studies on mass energy-absorption coefficients and effective atomic energy-absorption cross sections for carbohydrates

    NASA Astrophysics Data System (ADS)

    Ladhaf, Bibifatima M.; Pawar, Pravina P.

    2015-04-01

    We measured here the mass attenuation coefficients (μ/ρ) of carbohydrates, Esculine (C15H16O9), Sucrose (C12H22O11), Sorbitol (C6H14O6), D-Galactose (C6H12O6), Inositol (C6H12O6), D-Xylose (C5H10O5) covering the energy range from 122 keV up to 1330 keV photon energies by using gamma ray transmission method in a narrow beam good geometry set-up. The gamma-rays were detected using NaI(Tl) scintillation detection system with a resolution of 8.2% at 662 keV. The attenuation coefficient data were then used to obtain the total attenuation cross-section (σtot), molar extinction coefficients (ε), mass-energy absorption coefficients (μen/ρ) and effective (average) atomic energy-absorption cross section (σa,en) of the compounds. These values are found to be in good agreement with the theoretical values calculated based on XCOM data.

  10. Technical note: The effect of midshaft location on the error ranges of femoral and tibial cross-sectional parameters.

    PubMed

    Sládek, Vladimír; Berner, Margit; Galeta, Patrik; Friedl, Lukás; Kudrnová, Sárka

    2010-02-01

    In comparing long-bone cross-sectional geometric properties between individuals, percentages of bone length are often used to identify equivalent locations along the diaphysis. In fragmentary specimens where bone lengths cannot be measured, however, these locations must be estimated more indirectly. In this study, we examine the effect of inaccurately located femoral and tibial midshafts on estimation of geometric properties. The error ranges were compared on 30 femora and tibiae from the Eneolithic and Bronze Age. Cross-sections were obtained at each 1% interval from 60 to 40% of length using CT scans. Five percent of deviation from midshaft properties was used as the maximum acceptable error. Reliability was expressed by mean percentage differences, standard deviation of percentage differences, mean percentage absolute differences, limits of agreement, and mean accuracy range (MAR) (range within which mean deviation from true midshaft values was less than 5%). On average, tibial cortical area and femoral second moments of area are the least sensitive to positioning error, with mean accuracy ranges wide enough for practical application in fragmentary specimens (MAR = 40-130 mm). In contrast, tibial second moments of area are the most sensitive to error in midshaft location (MAR = 14-20 mm). Individuals present significant variation in morphology and thus in error ranges for different properties. For highly damaged fossil femora and tibiae we recommend carrying out additional tests to better establish specific errors associated with uncertain length estimates.

  11. Cross Section; Half Longitudinal Section Showing Middle Wall Reinforced with ...

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

    Cross Section; Half Longitudinal Section Showing Middle Wall Reinforced with Arch; Part Long Section Showing Inside of External Side Wall; East Entrance; Part Side South External; Part Reflected Plan of Soffite of Floor; Part Reflected Plan of Soffite of Roof - Blenheim Covered Bridge, Spanning Schoharie River, North Blenheim, Schoharie County, NY

  12. Intense laser field effects on the linear and nonlinear optical properties in a semiconductor quantum wire with triangle cross section

    NASA Astrophysics Data System (ADS)

    Barseghyan, M. G.; Duque, C. A.; Niculescu, E. C.; Radu, A.

    2014-02-01

    We study the laser field effects on the intersubband optical absorption and the refractive index changes in a GaAs/AlGaAs quantum wire with equilateral triangle cross section. The wire is under the action of a laser beam which is assumed to be non-resonant with the semiconductor structure and linearly polarized perpendicularly to the triangle side. In the effective mass approximation and for a finite potential barrier we calculate the subband states by using a finite element method. Linear, non linear and total absorption coefficients and refractive index changes are calculated as functions of the laser field for the allowed intersubband transitions. Two polarizations of the pump radiation, parallel and perpendicular to the laser field direction, are discussed.

  13. Cross sections for the formation of 69Znm,g and 71Znm,g in neutron induced reactions near their thresholds: Effect of reaction channel on the isomeric cross-section ratio

    NASA Astrophysics Data System (ADS)

    Nesaraja, C. D.; Sudár, S.; Qaim, S. M.

    2003-08-01

    Excitation functions were measured for the reactions 72Ge(n,α)69Znm,g, 69Ga(n,p)69Znm,g, 70Zn(n,2n)69Znm,g, 74Ge(n,α)71Znm,g, and 71Ga(n,p)71Znm,g over the neutron energy range of 6.3 12.4 MeV. Quasimonoenergetic neutrons in this energy range were produced via the 2H(d,n)3He reaction using a deuterium gas target at the Jülich variable energy compact cyclotron. Use was made of the activation technique in combination with high-resolution HPGe-detector γ-ray spectroscopy. In a few cases low-level β-counting was also applied. In order to decrease the interfering activities in those cases, either radiochemical separations were performed or isotopically enriched targets were used. For most of the reactions, the present measurements provide the first consistent sets of data near their thresholds. From the available experimental data, isomeric cross-section ratios were determined for the isomeric pair 69Znm,g in (n,α), (n,p), and (n,2n) reactions, and for the pair 71Znm,g in (n,α) and (n,p) reactions. Nuclear model calculations using the code STAPRE, which employs the Hauser-Feshbach (statistical model) and exciton model (precompound effects) formalisms, were undertaken to describe the formation of both isomeric and ground states of the products. The calculational results on the total (n,α), (n,p), and (n,2n) cross sections agree fairly well with the experimental data. The experimental isomeric cross-section ratios, however, are reproduced only approximately by the calculation. For both the isomeric pairs investigated, the isomeric cross-section ratio in the (n,p) reaction is higher than in other reactions.

  14. Neutrino Cross Sections at Solar Energies

    NASA Astrophysics Data System (ADS)

    Strigari, Louis

    2017-01-01

    I will review neutrino nucleus cross section measurements and uncertainties for energies applicable to solar neutrinos. I will discuss how these cross sections are important for interpreting solar neutrino experimental data, and highlight the most important neutrino-nucleus interactions that will be relevant for forthcoming dark matter direct detection experiments. NSF PHY-1522717.

  15. Neutrino flux predictions for cross section measurements

    SciTech Connect

    Hartz, Mark

    2015-05-15

    Experiments that measure neutrino interaction cross sections using accelerator neutrino sources require a prediction of the neutrino flux to extract the interaction cross section from the measured neutrino interaction rate. This article summarizes methods of estimating the neutrino flux using in-situ and ex-situ measurements. The application of these methods by current and recent experiments is discussed.

  16. Modernization of electron accelerator with a large cross section beam for radiation effects on materials

    NASA Astrophysics Data System (ADS)

    Vorobyov, M. S.; Denisov, V. V.; Koval, N. N.; Sulakshin, S. A.; Shugurov, V. V.; Yakovlev, V. V.

    2017-01-01

    The results of the work on the creation of an automated wide-aperture electron accelerator with a grid plasma cathode based on the low-pressure arc discharge and outputting of a large section beam (750×150 mm) in the atmosphere through a outlet foil window. The distinctive feature of such electron accelerator is a weak correlation of beam parameters, as well as a high current beam extraction efficiency to air, reaching ≈ (80 ÷ 90)% of the current in the accelerating gap at an accelerating voltage of 200 kV, beam current amplitude in the atmosphere up to 30A, frequency and pulse duration up to 50 s-1 and 100 μs, respectively. The electron source provides a stable continuous operation for tens of hours in a repetitively pulsed modes at the maximum average beam power in the atmosphere is ≈5 kW. Examples of applications of such accelerator in the radiation-stimulated technology are given, showing the prospects of its using in scientific and technological purposes.

  17. Effective Potential Energies and Transport Cross Sections for Atom-Molecule Interactions of Nitrogen and Nitrogen

    NASA Technical Reports Server (NTRS)

    Stallcop, James R.; Partridge, Harry; Levin, Eugene; Arnold, Jim (Technical Monitor)

    2001-01-01

    The potential energy surfaces for H2-N and N2-N interactions are calculated by accurate ab initio methods and applied to determine transport data. The results confirm that an effective potential energy for accurately determining transport properties can be calculated using a single orientation. A simple method is developed to determine the dispersion coefficients of effective potential energies Effective potential energies required for O2-O collisions are determ=ined. The H2-N, N2-N, O2-H, and O2-O collision integrals are calculated and tabulated for a large range of temperatures. The theoretical values of the N2-N and O2-O diffusion coefficients compare well with measured data available at room temperature.

  18. Effect of pylon cross-sectional geometries on propulsion integration for a low-wing transport

    NASA Technical Reports Server (NTRS)

    Ingraldi, Anthony M.; Naik, Dinesh A.; Pendergraft, Odis C., Jr.

    1993-01-01

    An experimental program was conducted in the Langley 16-Foot Transonic Tunnel to evaluate the performance effects of various types of pylons on a 1/17th-scale, low-wing transport model. The model wing was designed for cruise at a Mach number of 0.77 and a lift coefficient of 0.55. The pylons were tested at two wing semispan locations over a range of toe-in angles. The effects of toe-in angle were found to be minimal, but the variation in geometry had a more pronounced effect on the lift characteristics of the model. A pylon whose maximum thickness occurred at the wing trailing edge, known as a compression pylon, proved to be the best choice in terms of retaining the flow characteristics of the wing without pylons. Practical considerations such as structural viability may necessitate modification of the compression pylon concept in order to take advantage of its apparent benefits.

  19. Cross-sectional anatomy for computed tomography

    SciTech Connect

    Farkas, M.L.

    1988-01-01

    This self-study guide recognizes that evaluation and interpretation of CT-images demands a firm understanding of both cross-sectional anatomy and the principles of computed tomography. The objectives of this book are: to discuss the basic principles of CT, to stress the importance of cross-sectional anatomy to CT through study of selected cardinal transverse sections of head, neck, and trunk, to explain orientation and interpretation of CT-images with the aid of corresponding cross-sectional preparations.

  20. Electron collisions with phenol: Total, integral, differential, and momentum transfer cross sections and the role of multichannel coupling effects on the elastic channel.

    PubMed

    da Costa, Romarly F; de Oliveira, Eliane M; Bettega, Márcio H F; Varella, Márcio T do N; Jones, Darryl B; Brunger, Michael J; Blanco, Francisco; Colmenares, Rafael; Limão-Vieira, Paulo; García, Gustavo; Lima, Marco A P

    2015-03-14

    We report theoretical and experimental total cross sections for electron scattering by phenol (C6H5OH). The experimental data were obtained with an apparatus based in Madrid and the calculated cross sections with two different methodologies, the independent atom method with screening corrected additivity rule (IAM-SCAR), and the Schwinger multichannel method with pseudopotentials (SMCPP). The SMCPP method in the Nopen-channel coupling scheme, at the static-exchange-plus-polarization approximation, is employed to calculate the scattering amplitudes at impact energies ranging from 5.0 eV to 50 eV. We discuss the multichannel coupling effects in the calculated cross sections, in particular how the number of excited states included in the open-channel space impacts upon the convergence of the elastic cross sections at higher collision energies. The IAM-SCAR approach was also used to obtain the elastic differential cross sections (DCSs) and for correcting the experimental total cross sections for the so-called forward angle scattering effect. We found a very good agreement between our SMCPP theoretical differential, integral, and momentum transfer cross sections and experimental data for benzene (a molecule differing from phenol by replacing a hydrogen atom in benzene with a hydroxyl group). Although some discrepancies were found for lower energies, the agreement between the SMCPP data and the DCSs obtained with the IAM-SCAR method improves, as expected, as the impact energy increases. We also have a good agreement among the present SMCPP calculated total cross section (which includes elastic, 32 inelastic electronic excitation processes and ionization contributions, the latter estimated with the binary-encounter-Bethe model), the IAM-SCAR total cross section, and the experimental data when the latter is corrected for the forward angle scattering effect [Fuss et al., Phys. Rev. A 88, 042702 (2013)].

  1. The Effect of N2 Photoabsorption Cross Section Resolution on C2H6 Production in Titan’s Ionosphere

    NASA Astrophysics Data System (ADS)

    Luspay-Kuti, Adrienn; Mandt, Kathleen E.; Plessis, Sylvain; Greathouse, Thomas K.

    2014-11-01

    Titan’s rich organic chemistry begins with the photochemistry of only two molecules: N2 and CH4. The details on how higher-order hydrocarbons and nitriles are formed from these molecules have key implications for both the structure and evolution of Titan’s atmosphere, and for its surface-atmosphere interactions. Of high importance is the production of C2H6, which is a sink for CH4, and a main component in the polar lakes. Results of photochemical models, though, may be sensitive to the choice of input parameters, such as the N2 photoabsorption cross section resolution, as previously shown for nitrogen (Liang et al. (2007) ApJL 664, 115-118), and CH4 (Lavvas et al. (2011) Icarus 213, 233-251). Here we investigate the possibility of the same effect on the production rates of C2H6. We modeled production and loss rates, as well as mixing ratio and density profiles between an altitude of 600 and 1600 km for low and high resolution N2 cross sections via a coupled ion-neutral-thermal model (De La Haye et al. (2008) Icarus 197, 110-136; Mandt et al. (2012) JGR 117, E10006). Our results show a clear impact of photoabsorption cross section resolution used on all neutral and ion species contributing to C2H6 production. The magnitude of the influence varies amongst species. Ethane production profiles exhibit a significant increase with better resolution; a factor of 1.2 between 750 and 950 km, and a factor of 1.1 in the total column-integrated production rate. These values are lower limits, as additional reactions involving C2H5 not included in the model may also contribute to the production rates. The clear effect on C2H6 (which is not a parent molecule, nor does it bear nitrogen) may have important implications for other molecules in Titan’s atmosphere as well. The possible non-negligible impact of an isotope of nitrogen may argue for the inclusion of isotopes in photochemical models. For future analysis, development of a more efficient and streamlined model called

  2. Effects of air pollution on the respiratory health of children: a cross-sectional study

    SciTech Connect

    Spinaci, S.; Arossa, W.; Bugiani, M.; Natale, P.; Bucca, C.; de Candussio, G.

    1985-09-01

    To investigate the effects of air pollution on the respiratory health of children, a subject of some controversy, a comparative study was undertaken of 2,385 school children who lived in central urban, peripheral urban, and suburban areas. Daily monitoring of sulfur dioxide and total suspended particle concentrations in all areas showed that pollutant concentrations in central and peripheral urban areas were above commonly accepted safety levels for respiratory health, while concentrations in the suburban area were within acceptable limits. A questionnaire administered to each mother assessed environmental exposure to pollutants in the household, the occurrence of respiratory symptoms as well as lung diseases as diagnosed by a physician, and general information. Children were interviewed about smoking habits and any acute respiratory symptoms. Children also performed standard lung function tests. Results showed that children from both urban areas had lessened pulmonary function and a higher prevalence of bronchial secretion with common colds than did those from the suburban area. These differences persisted after corrections for exposure to indoor pollutants, active or passive smoking, socioeconomic status, and sex. Parental cigarette smoking was related to a fall in forced expiratory volume in 1 second and an increased incidence of acute respiratory illnesses and chronic cough in children. Although boys had higher lung volumes and lower air flow, regression analysis showed no significant influence of the interactions sex-geographic area and sex-smoking on lung function. It was concluded that air pollution has a significant effect on the respiratory health of children.

  3. Cross-Sectional Investigations on Epitaxial Silicon Solar Cells by Kelvin and Conducting Probe Atomic Force Microscopy: Effect of Illumination.

    PubMed

    Narchi, Paul; Alvarez, Jose; Chrétien, Pascal; Picardi, Gennaro; Cariou, Romain; Foldyna, Martin; Prod'homme, Patricia; Kleider, Jean-Paul; I Cabarrocas, Pere Roca

    2016-12-01

    Both surface photovoltage and photocurrent enable to assess the effect of visible light illumination on the electrical behavior of a solar cell. We report on photovoltage and photocurrent measurements with nanometer scale resolution performed on the cross section of an epitaxial crystalline silicon solar cell, using respectively Kelvin probe force microscopy and conducting probe atomic force microscopy. Even though two different setups are used, the scans were performed on locations within 100-μm distance in order to compare data from the same area and provide a consistent interpretation. In both measurements, modifications under illumination are observed in accordance with the theory of PIN junctions. Moreover, an unintentional doping during the deposition of the epitaxial silicon intrinsic layer in the solar cell is suggested from the comparison between photovoltage and photocurrent measurements.

  4. Effect of fiber orientation and cross section of composite tubes on their energy absorption ability in axial dynamic loading

    NASA Astrophysics Data System (ADS)

    Shokrieh, M. M.; Tozandehjani, H.; Omidi, M. J.

    2009-11-01

    The crushing behavior of composite tubes in axial impact loading is investigated. Tubes of circular and rectangular cross section are simulated using an LS-DYNA software. The effect of fiber orientation on the energy absorbed in laminated composite tubes is also studied. The results obtained show that rectangular tubes absorb less energy than circular ones, and their maximum crushing load is also lower. The composite tubes with a [+θ/ -θ] lay-up configuration absorb a minimum amount of energy at θ = 15°. The simulation results for a rectangular composite tube with a [+30/-30] lay-up configuration are compared with available experimental data. Cylindrical composite tubes fabricated from woven glass/polyester composites with different lay-ups were also tested using a drop-weight impact tester, and very good agreement between experimental and numerical results is achieved.

  5. Effect of Communication Skills Training on the Burnout of Nurses: A Cross-Sectional Study

    PubMed Central

    Darban, Fatemeh; Balouchi, Abbas; Narouipour, Abdullreza; Shahdadi, Hosein

    2016-01-01

    Introduction One of the factors influencing the burnout of nurses is their difficult and complicated relations with patients and other members of the medical team. Therefore, it is necessary that nurses to be trained on communication skills. Aim The present research aims to study the effect of communication skills training on the burnout of nurses. Materials and Methods The present research was an experimental study using pretest-posttest method. The subjects included 60 nurses working in Khatamolanbia Hospital in Iranshahr, Sistan and Baluchestan Province, Iran. The subjects were randomly divided into two groups. The required data and information were collected using Jackson and Maslach Burnout Inventory which was filled out by subjects in three steps including before the intervention, at the end of the second session, and one month after the intervention. The intervention included training on communication skills which was carried out for the intervention group as a 2-day workshop for 8 hours within a week. Results The findings showed that the mean score of frequency and intensity of burnout in the intervention group before the intervention, at the end of the intervention, and one month after the intervention was 39.3±6.2 and 61.1±8.0, 37.5±4.6 and 58.8±7.6, and 34.2±4.4 and 54.6±7.0, respectively. These changes suggest a significant decreasing trend (p=0.01). On the other hand, mean scores of burnout in the control group showed no significant difference in three steps (p<0.05). Conclusion Since communication skills training is an effective and inexpensive way for reducing the burnout among nurses, it is recommended that this approach to be taken into account by managers in order to reduce the burnout among nurses and improve the quality of healthcare services provided by them. PMID:27190832

  6. Cross-sectional Study of Vitamin D and Calcium Supplementation Effects on Chronic Periodontitis

    PubMed Central

    Miley, D. Douglas; Garcia, M. Nathalia; Hildebolt, Charles F.; Shannon, William D.; Couture, Rex A.; Anderson Spearie, Catherine L.; Dixon, Debra A.; Langenwalter, Eric M.; Mueller, Cheryl; Civitelli, Roberto

    2013-01-01

    Background Low dietary intakes of vitamin D and calcium hasten bone loss and osteoporosis. Because vitamin D metabolites may also alter the inflammatory response and have anti-microbial effects, we studied whether use of vitamin D and calcium supplements affects periodontal disease status. Methods A cohort of 51 subjects receiving periodontal maintenance therapy was recruited from 2 dental clinics. Of these, 23 were taking vitamin D (≥400 international units/day) and calcium (≥1000mg/day) supplementation, and 28 were not taking such supplementation. All subjects had ≥2 interproximal sites with ≥3 mm clinical attachment loss. Daily calcium and vitamin D intakes (from food and supplements) were estimated by nutritional analysis. The following clinical parameters of periodontal disease were recorded for the mandibular posterior teeth: gingival index, probing depth, cementoenamel junction-gingival margin distance (attachment loss), bleeding upon probing, and furcation involvement. Posterior photostimulable-phosphor bitewing radiographs were taken to determine cementoenamel-junction-alveolar-crest distances (alveolar crest height loss). Data were analyzed with a repeated-measures, multivariate analysis of variance. Results Relative to subjects who did not take vitamin D and calcium supplementation, supplement takers had shallower probing depths, fewer bleeding sites, lower gingival index values, fewer furcation involvements, less attachment loss and less alveolar crest height loss. The repeated-measures analysis indicated that collectively these differences for clinical parameters were borderline significant (P=0.08). Conclusion In these subjects receiving periodontal maintenance therapy, there was a trend for better periodontal health with intake of vitamin D and calcium supplementation. More expanded longitudinal studies are required to determine the potential of this relationship. PMID:19722793

  7. Nucleon-Nucleon Total Cross Section

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    2008-01-01

    The total proton-proton and neutron-proton cross sections currently used in the transport code HZETRN show significant disagreement with experiment in the GeV and EeV energy ranges. The GeV range is near the region of maximum cosmic ray intensity. It is therefore important to correct these cross sections, so that predictions of space radiation environments will be accurate. Parameterizations of nucleon-nucleon total cross sections are developed which are accurate over the entire energy range of the cosmic ray spectrum.

  8. Neutron Capture Cross Section of 239Pu

    NASA Astrophysics Data System (ADS)

    Mosby, S.; Arnold, C.; Bredeweg, T. A.; Chyzh, A.; Couture, A.; Henderson, R.; Jandel, M.; Kwan, E.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Wu, C. Y.

    2014-05-01

    The Detector for Advanced Neutron Capture Experiments (DANCE) has been used to measure the 239Pu(n,γ) cross section from 10 eV to the keV region. Three experimental run conditions were used to characterize the prompt fission γ-ray spectrum across the entire energy regime, measure the cross section in the resolved resonance region, and obtain necessary count rate well into the keV region. The preliminary cross sections are in good agreement with current evaluations from 10 eV to 80 keV.

  9. K-shell photoionization cross-sections.

    NASA Technical Reports Server (NTRS)

    Daltabuit, E.; Cox, D. P.

    1972-01-01

    Approximate values for the threshold energies, threshold cross sections, and energy dependence of the cross sections for K-shell photoionization are tabulated for H, He, C, N, O, Ne, Mg, Si, and S in all stages of ionization. The approximation of these data is based on the assumptions that the threshold energy is a simple function of the nuclear charge and the number of electrons present in the atom, and that the threshold values and energy dependence of the cross sections are determined only by the threshold energy.

  10. Cross Section Evaluations for Arsenic Isotopes

    SciTech Connect

    Pruet, J; McNabb, D P; Ormand, W E

    2005-03-10

    The authors present an evaluation of cross sections describing reactions with neutrons incident on the arsenic isotopes with mass numbers 75 and 74. Particular attention is paid to (n,2n) reactions. The evaluation for {sup 75}As, the only stable As isotope, is guided largely by experimental data. Evaluation for {sup 74}As is made through calculations with the EMPIRE statistical-model reaction code. Cross sections describing the production and destruction of the 26.8 ns isomer in {sup 74}As are explicitly considered. Uncertainties and covariances in some evaluated cross sections are also estimated.

  11. Is antipsychotic polypharmacy associated with metabolic syndrome even after adjustment for lifestyle effects?: a cross-sectional study

    PubMed Central

    2011-01-01

    Background Although the validity and safety of antipsychotic polypharmacy remains unclear, it is commonplace in the treatment of schizophrenia. This study aimed to investigate the degree that antipsychotic polypharmacy contributed to metabolic syndrome in outpatients with schizophrenia, after adjustment for the effects of lifestyle. Methods A cross-sectional survey was carried out between April 2007 and October 2007 at Yamanashi Prefectural KITA hospital in Japan. 334 patients consented to this cross-sectional study. We measured the components consisting metabolic syndrome, and interviewed the participants about their lifestyle. We classified metabolic syndrome into four groups according to the severity of metabolic disturbance: the metabolic syndrome; the pre-metabolic syndrome; the visceral fat obesity; and the normal group. We used multinomial logistic regression models to assess the association of metabolic syndrome with antipsychotic polypharmacy, adjusting for lifestyle. Results Seventy-four (22.2%) patients were in the metabolic syndrome group, 61 (18.3%) patients were in the pre-metabolic syndrome group, and 41 (12.3%) patients were in visceral fat obesity group. Antipsychotic polypharmacy was present in 167 (50.0%) patients. In multinomial logistic regression analyses, antipsychotic polypharmacy was significantly associated with the pre-metabolic syndrome group (adjusted odds ratio [AOR], 2.348; 95% confidence interval [CI], 1.181-4.668), but not with the metabolic syndrome group (AOR, 1.269; 95%CI, 0.679-2.371). Conclusions These results suggest that antipsychotic polypharmacy, compared with monotherapy, may be independently associated with an increased risk of having pre-metabolic syndrome, even after adjusting for patients' lifestyle characteristics. As metabolic syndrome is associated with an increased risk of cardiovascular mortality, further studies are needed to clarify the validity and safety of antipsychotic polypharmacy. PMID:21791046

  12. Coupled multigroup cross sections for hydrogen interactions in plasmas

    NASA Astrophysics Data System (ADS)

    Wienke, B. R.; Morel, J. E.; Cayton, T. E.; Howell, R. B.

    1985-10-01

    Using analytical fits to the experimental cross sections for H 3 H 2, and H 2+ interactions in plasmas, developed by Gryzinski, Riviere, Jones, and Freeman, we obtain coupled multigroup cross sections and rate coefficients for hydrogen transport applications. Multigroup cross sections and rate coefficients, for specified energy group boundaries, plasma particle and temperature profiles, and cylindrical plasma confinement radius, are generated against a spatially dependent, local Maxwellian scattering background. Cross sections are formatted for direct use in production multigroup S n, Monte Carlo, or specific transport applications. Ten coupled hydrogen reactions are included and resulting cross sections for ionization, scattering, and production can be coupled or decoupled. Reactions treated include H, H 2 ionization by electrons and protons, H, H 2 charge exchange, and H 2, H 2+ dissociative mechanisms. We detail the formalism used to compute effective cross sections and rates and give practicle results for two fusion reactors.

  13. [A cross- sectional study to evaluate the effects of introducing a Bachelor of Science in Nursing and Midwifery in Italy].

    PubMed

    Dante, Angelo; Miniussi, Claudia; Margetic, Helga; Palese, Alvisa

    2011-01-01

    The effects of advanced nursing education have been documented at the international level but there is little information available in the Italian context. In Italy, the university nursing degree was introduced almost ten years ago and is facing its first reform. The aim of this study was to describe the effects of the Bachelor of Science in Nursing and Midwifery on skills as perceived by graduates of the school, and on professional and career development. A cross-sectional study design was used. All students who attended the nursing/midwifery program of the University of Udine and Trieste from 2005/2006 to 2008/2009 (n= 114) were considered eligible to participate. Participating students completed a self-assessment portfolio a few months after registering in the program and again upon completion of the program. Effects on professional and career development were assessed through a questionnaire. All participants reported having received one or more positive effects on their professional development. Only 19% of participants obtained a career advancement within 12 months of completing the program.

  14. A cross-sectional analysis of dioxins and health effects in municipal and private waste incinerator workers in Japan

    PubMed Central

    YAMAMOTO, Kenya; KUDO, Mitsuhiro; ARITO, Heihachiro; OGAWA, Yasutaka; TAKATA, Tsutomu

    2015-01-01

    This cross-sectional study was intended to examine health effects of 678 male workers employed during an 8-yr period from 2000 to 2007 at 36 municipal and private waste incineration plants in Japan. Blood samples were obtained for analysis of concentrations of dioxins including coplanar polychlorinated biphenyls (coplanar PCBs) and evaluation of health effects. Health effects including diabetes were surveyed via a physician’s interview or clinical data from blood samples. There was a certain difference in serum concentrations of polychlorinated dibenzofurans (PCDFs) between the incinerator workers and Japanese general population, although no differences in the concentrations of total dioxins or polychlorinated dibenzo-p-dioxins (PCDDs) were found between the two groups. A few positive correlations between serum levels of PCDDs and PCDFs and the results of laboratory and physiological tests were found, but coplanar PCBs showed significant relations with 14 parameters of the tests. The background serum levels of PCDDs, PCDFs and total dioxins were significantly associated with the prevalence of diabetes. No essential differences in serum concentrations of total dioxins and in prevalence of diabetes between our subjects and the general population suggested that the incinerator workers were marginally exposed to dioxins in the workplace without any recognizable adverse health effects. PMID:26212412

  15. A cross-sectional analysis of dioxins and health effects in municipal and private waste incinerator workers in Japan.

    PubMed

    Yamamoto, Kenya; Kudo, Mitsuhiro; Arito, Heihachiro; Ogawa, Yasutaka; Takata, Tsutomu

    2015-01-01

    This cross-sectional study was intended to examine health effects of 678 male workers employed during an 8-yr period from 2000 to 2007 at 36 municipal and private waste incineration plants in Japan. Blood samples were obtained for analysis of concentrations of dioxins including coplanar polychlorinated biphenyls (coplanar PCBs) and evaluation of health effects. Health effects including diabetes were surveyed via a physician's interview or clinical data from blood samples. There was a certain difference in serum concentrations of polychlorinated dibenzofurans (PCDFs) between the incinerator workers and Japanese general population, although no differences in the concentrations of total dioxins or polychlorinated dibenzo-p-dioxins (PCDDs) were found between the two groups. A few positive correlations between serum levels of PCDDs and PCDFs and the results of laboratory and physiological tests were found, but coplanar PCBs showed significant relations with 14 parameters of the tests. The background serum levels of PCDDs, PCDFs and total dioxins were significantly associated with the prevalence of diabetes. No essential differences in serum concentrations of total dioxins and in prevalence of diabetes between our subjects and the general population suggested that the incinerator workers were marginally exposed to dioxins in the workplace without any recognizable adverse health effects.

  16. Neutron capture cross section of {sup 102}Pd

    SciTech Connect

    Duncan, C.L.; Krane, K.S.

    2005-05-01

    The cross sections for radiative neutron capture by {sup 102}Pd have been deduced from a measurement of the {gamma} rays emitted by 17.0-d {sup 103}Pd. The thermal cross section has been determined to be {sigma}=1.82{+-}0.20 b, and the effective resonance integral is I=23{+-}4 b. We also report thermal and resonance capture cross sections for {sup 108}Pd and note possible inconsistencies with the presently accepted values of the {sup 110}Pd cross sections.

  17. Benchmark cross sections for bottom quark production

    SciTech Connect

    Berger, E.L.

    1988-01-07

    A summary is presented of theoretical expectations for the total cross sections for bottom quark production, for longitudinal and transverse momentum distributions, and for b, /bar b/ momentum correlations at Fermilab fixed target and collider energies.

  18. Bibliography of photoabsorption cross-section data

    NASA Technical Reports Server (NTRS)

    Hudson, R. D.; Kieffer, L. J.

    1970-01-01

    This bibliography contains only references which report a measured or calculated photoabsorption cross section (relative or normalized) in regions of continuous absorption. The bibliography is current as of January 1, 1970.

  19. A nuclear cross section data handbook

    SciTech Connect

    Fisher, H.O.M.

    1989-12-01

    Isotopic information, reaction data, data availability, heating numbers, and evaluation information are given for 129 neutron cross-section evaluations, which are the source of the default cross sections for the Monte Carlo code MCNP. Additionally, pie diagrams for each nuclide displaying the percent contribution of a given reaction to the total cross section are given at 14 MeV, 1 MeV, and thermal energy. Other information about the evaluations and their availability in continuous-energy, discrete-reaction, and multigroup forms is provided. The evaluations come from ENDF/B-V, ENDL85, and the Los Alamos Applied Nuclear Science Group T-2. Graphs of all neutron and photon production cross-section reactions for these nuclides have been categorized and plotted. 21 refs., 5 tabs.

  20. The radar cross section of dielectric disks

    NASA Technical Reports Server (NTRS)

    Levine, D. M.

    1982-01-01

    A solution is presented for the backscatter (nonstatic) radar cross section of dielectric disks of arbitrary shape, thickness and dielectric constant. The result is obtained by employing a Kirchhoff type approximation to obtain the fields inside the disk. The internal fields induce polarization and conduction currents from which the scattered fields and the radar cross section can be computed. The solution for the radar cross section obtained in this manner is shown to agree with known results in the special cases of normal incidence, thin disks and perfect conductivity. The solution can also be written as a product of the reflection coefficient of an identically oriented slab times the physical optics solution for the backscatter cross section of a perfectly conducting disk of the same shape. This result follows directly from the Kirchhoff type approximation without additional assumptions.

  1. Energy dependence of fusion cross sections

    SciTech Connect

    Bang, J.M.; Ferreira, L.S.; Maglione, E.; Hansteen, J.M.

    1996-01-01

    Observed enhancements of fusion cross sections at low energies are explained as caused by an underestimate of beam energy due to an overestimate of the stopping energy loss. {copyright} {ital 1996 The American Physical Society.}

  2. MODELING AND FISSION CROSS SECTIONS FOR AMERICIUM.

    SciTech Connect

    ROCHMAN, D.; HERMAN, M.; OBLOZINSKY, P.

    2005-05-01

    This is the final report of the work performed under the LANL contract on the modeling and fission cross section for americium isotopes (May 2004-June 2005). The purpose of the contract was to provide fission cross sections for americium isotopes with the nuclear reaction model code EMPIRE 2.19. The following work was performed: (1) Fission calculations capability suitable for americium was implemented to the EMPIRE-2.19 code. (2) Calculations of neutron-induced fission cross sections for {sup 239}Am to {sup 244g}Am were performed with EMPIRE-2.19 for energies up to 20 MeV. For the neutron-induced reaction of {sup 240}Am, fission cross sections were predicted and uncertainties were assessed. (3) Set of fission barrier heights for each americium isotopes was chosen so that the new calculations fit the experimental data and follow the systematics found in the literature.

  3. The radar cross section of dielectric disks

    NASA Technical Reports Server (NTRS)

    Le Vine, D. M.

    1984-01-01

    A solution is presented for the backscatter (monostatic) radar cross section of dielectric disks of arbitrary shape, thickness, and dielectric constant. The result is obtained by employing a Kirchhoff-type approximation to obtain the fields inside the disk. The internal fields induce polarization and conduction currents from which the scattered fields and the radar cross section can be computed. The solution for the radar cross section obtained in this manner will be shown to agree with known results in the special cases of normal incidence, thin disks, and perfect conductivity. It will also be shown that the solution can be written as a product of the reflection coefficient of an identically oriented slab times the physical optics solution for the backscatter cross section of a perfectly conducting disk of the same shape. This result follows directly from the Kirchhoff-type approximation without additional assumptions.

  4. Evaluation of the effective cross-sections for recombination and trapping in the case of pure spinel.

    PubMed

    Boughariou, A; Damamme, G; Kallel, A

    2015-03-01

    In this paper, we have investigated the evolution of the secondary electron emission in the case of pure spinel during electron irradiation, achieved in a scanning electron microscope at room temperature, which is derived from the measurement of the induced and the secondary electron currents. It was observed from the experimental results, that there are two regimes during the charging process: a plateau followed by a linear variation, which are better identified by plotting the logarithm of the secondary electron emission yield lnσ as function of the total surface density of trapped charges in the material QT . For positive charging, E0 = 1.1 and 5 keV, the slope of the linear part, whose value is of about 10(-10) cm(2) charge(-1), is independent of the primary electron energy. It is interpreted as a microscopic cross section for electron-hole recombination. For negative charging of pure spinel, E0 = 15 and 30 keV, the slope is associated with an electron trapping cross section close to 10(-14) cm(2) charge(-1), which can be assigned to the microscopic cross section for electron trapping. This trapping cross section is four orders of magnitude lower than the recombination one.

  5. Patient perceptions of glucocorticoid side effects: a cross-sectional survey of users in an online health community

    PubMed Central

    Patel, Rikesh; Humphreys, Jennifer; McBeth, John; Dixon, William G

    2017-01-01

    Objectives To identify the side effects most important to glucocorticoid (GC) users through a survey of a UK online health community (Healthunlocked.com). Design Online cross-sectional survey. Setting Participants were recruited through Healthunlocked.com, an online social network for health. Participants Adults who were currently taking GCs, or had taken GCs in the past month. Method Responders scored the importance of listed side effects from 1 to 10, with 10 being of high importance to them. For each side effect, histograms were plotted, and the median rating and IQR were determined. Side effects were ranked by median ranking (largest to smallest) and then IQR (smallest to largest). The scores were categorised as low (scores 1–3), medium (scores 4–7) and high (scores 8–10) importance. Results 604 responders completed the survey. Histograms of side effect scores showed a skew towards high importance for weight gain, a U-shaped distribution for cardiovascular disease (CVD), diabetes, eye disease and infections, and a skew towards low importance for acne. When ranked, the side effect of most importance to responders was weight gain (median score=9, IQR 6–10) followed by insomnia and moon face with equal median score (8) and IQR (5–10). Three serious side effects, CVD, diabetes and infections, were ranked of lower importance overall but had wide ranging scores (median score=8, IQR 1–10). Conclusions The three most highly rated side effects were not clinically serious but remained important to patients, perhaps reflecting their impact on quality of life and high prevalence. This should be taken into consideration when discussing treatment options and planning future GC safety studies. PMID:28373256

  6. Ultraviolet absorption cross sections of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Lin, C. L.; Rohatgi, N. K.; Demore, W. B.

    1978-01-01

    Absorption cross-sections of hydrogen peroxide vapor and of neutral aqueous solutions of hydrogen peroxide were measured in the wavelength range from 195 to 350 nm at 296 K. The spectrophotometric procedure is described, and the reported cross-sections are compared with values obtained by other researchers. Photodissociation coefficients of atmospheric H2O2 were calculated for direct absorption of unscattered solar radiation, and the vertical distributions of these coefficients are shown for various solar zenith angles.

  7. Effect of gonadal hormones on the cross-sectional area of pubococcygeus muscle fibers in male rat.

    PubMed

    Alvarado, Mayvi; Cuevas, Estela; Lara-García, Miguel; Camacho, Miguel; Carrillo, Porfirio; Hudson, Robyn; Pacheco, Pablo

    2008-05-01

    Effects of gonadal hormones on dimorphic striated muscles such as the bulbocavernosus/levator ani complex related to male penile erection have been widely studied. However, the action of these hormones on pelvic nondimorphic muscles is not known. In the present study, the sensitivity of the male rat pubococcygeus muscle (Pcm) to gonadal hormones was studied measuring the cross-sectional area (CSA) of its fibers. For this, two experiments were done: in the first, the effect of castration, and in the second the effect of gonadal hormone administration was analyzed. We found that castration after 6 weeks significantly reduced the average CSA of the fibers of this muscle and that castration after 2 or 6 weeks reduced the percentage of fibers with higher CSAs, but only castration after 6 weeks increased the percentage of fibers with the lowest CSA. In comparison with castrated animals implanted with an empty Silastic capsule, Silastic implants of testosterone propionate or dihydrotestosterone significantly increased the average CSA of Pcm fibers, and the treatment with testosterone propionate, estradiol benzoate, or dihydrotestosterone decreased the percentage of fibers with low CSAs and increased the percentage with larger CSAs. Our results could be considered for therapy in patients with damage of the Pcm, and suffering urinary incontinence or ejaculatory dysfunctions.

  8. QuickSite Cross Section Processing

    SciTech Connect

    Richard Becker, ANL

    2003-05-27

    This AGEM-developed system produces cross sections by inputting data in both standard and custom file formats and outputting a graphic file that can be printed or further modified in a commercial graphic program. The system has evolved over several years in order to combine and visualize a changing set of field data more rapidly than was possible with commercially available cross section software packages. It uses some commercial packages to produce the input and to modify the output files. Flexibility is provided by a dynamic set of programs that are customized to accept varying input and accomodate varying output requirements. There are two basic types of routines: conversion routines and cross section generation routines. The conversion routines convery various data files to logger file format which is compatible with a standard file format for LogPlot 98, a commonly used commercial log plotting program. The cross section routines generate cross sections and apply topography to these cross sections. All of the generation routines produce a standard graphic DXF file, which is the format used in AutoCAD and can then be modified in a number of available graphics programs.

  9. Hormonal Treatment Effects on the Cross-sectional Area of Pubococcygeus Muscle Fibers After Denervation and Castration in Male Rats.

    PubMed

    Lara-García, Miguel; Alvarado, Mayvi; Cuevas, Estela; Lara-García, Omar; Sengelaub, Dale R; Pacheco, Pablo

    2017-02-08

    We explore the interaction of muscle innervation and gonadal hormone action in the pubococcygeus muscle (Pcm) after castration and hormone replacement. Male Wistar rats were castrated and the Pcm was unilaterally denervated; after 2 or 6 weeks, the cross-sectional area (CSA) of Pcm fibers was assessed. Additional groups of castrated rats were used to examine the effects of hormone replacement. At 2 weeks post surgeries, rats were implanted with Silastic capsules containing either dihydrotestosterone (DHT), estradiol benzoate (EB) or both hormones, and the CSA of Pcm fibers was assessed after 4 weeks of hormone treatment. At 2 weeks post surgeries, gonadectomy without hormone replacement resulted in reductions in the CSA of Pcm fibers, and denervation combined with castration increased the magnitude of this effect; further reductions in CSA were present at 6 weeks post surgeries, but again denervation combined with castration increased the magnitude of this effect. Hormone replacement with DHT resulted in hypertrophy in the CSA of nondenervated muscles compared to those of intact normal males, but this effect was attenuated in denervated muscles. Hormone replacement with EB treatment prevented further castration-induced reductions in CSA of nondenervated muscles, but denervation prevented this effect. Similar to that seen with treatment with EB alone, combined treatment with both DHT and EB prevented further reductions in CSA of Pcm fibers in nondenervated muscles, but again denervation attenuated this effect. Thus, while hormone replacement can reverse or prevent further castration-induced atrophy of Pcm fibers, these effects are dependent on muscle innervation. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc.

  10. Effects of clozapine on perceptual abnormalities and sensory gating: a preliminary cross-sectional study in schizophrenia.

    PubMed

    Micoulaud-Franchi, Jean-Arthur; Aramaki, Mitsuko; Geoffroy, Pierre Alexis; Richieri, Raphaëlle; Cermolacce, Michel; Faget, Catherine; Ystad, Sølvi; Kronland-Martinet, Richard; Lancon, Christophe; Vion-Dury, Jean

    2015-04-01

    The aim of the present study was to investigate the effect of second-generation antipsychotics (clozapine or another second-generation antipsychotic) on perceptual abnormalities related to sensory gating deficit. Although clozapine is known to improve sensory gating assessed neurophysiologically, we hypothesized that patients with schizophrenia treated with clozapine would report less perceptual abnormalities related to sensory gating deficit than patients treated with other second-generation antipsychotics do. Forty patients with a diagnosis of schizophrenia were investigated (10 patients treated with clozapine and 30 patients treated with another second-generation antipsychotic drug). Perceptual abnormalities were assessed with the Sensory Gating Inventory. Sensory gating was assessed through electroencephalogram with the auditory event-related potential method by measuring P50 amplitude changes in a dual click conditioning-testing procedure. Patients treated with clozapine present normal sensory gating and report less perceptual abnormalities related to sensory gating than patients treated with other second-generation antipsychotics do. Although the cross-sectional design of this study is limited because causal inferences cannot be clearly concluded, the present study suggests clinical and neurophysiological advantages of clozapine compared with other second-generation antipsychotics and provides a basis for future investigations on the effect of this treatment on perceptual abnormalities related to sensory gating deficit in patients with schizophrenia.

  11. Health effects of perceived racial and religious bullying among urban adolescents in China: a cross-sectional national study.

    PubMed

    Pan, Stephen W; Spittal, Patricia M

    2013-07-01

    Research concerning ethnocultural bullying and adolescent health in China remains extremely limited. This study among Chinese urban adolescents examines associations between ethnocultural bullying and eight health-related outcomes: suicidal ideation, suicide planning, depressive symptomology, anxiety symptomatology, fighting, injury intentionally inflicted by another, smoking and moderate/heavy alcohol consumption. Data were obtained from the World Health Organisation's 2003 Chinese Global School-based Health Survey, a cross-sectional national survey of urban adolescents in four Chinese cities. The analytic sample size was n = 8182, which represented a sampling frame of 769,835 adolescents. Statistical analysis was conducted using generalised linear mixed effects models and sampling weights. Prevalence of ethnocultural bullying was significantly higher in Urumqi, Xinjiang province (2.08%) compared with Beijing municipality (0.72%) or Wuhan, Hubei province (0.67%). Compared to participants who were not bullied, religious bullying victimisation was significantly associated with suicidal ideation, injury intentionally inflicted by another and depressive symptomology. Racial bullying victimisation was significantly associated with suicidal ideation, injury intentionally inflicted by another and among females but not males, depressive symptomology. Health effects of ethnocultural bullying appear to be distinct from that of bullying in general. Additional research on ethnocultural adolescent health issues in China is warranted.

  12. No preventive effect of dietary fiber against colon cancer in the Japanese population: a cross-sectional analysis.

    PubMed

    Nakaji, Shigeyuki; Shimoyama, Tadashi; Wada, Seiko; Sugawara, Kazuo; Tokunaga, Shoji; MacAuley, Domhnall; Baxter, David

    2003-01-01

    The report of Fuchs et al. in 1999 on the protective effects of dietary fiber (DF) against colon carcinogenesis has led many researchers to question the benefits of DF. We analyzed the relationship between dietary intake and mortality from colon cancer in Japan cross-sectionally. Dietary data were taken from the National Nutrition Survey. The standardized mortality ratio (SMR) was calculated using data from "Vital Statistics" and "the Population Census in Japan." Multiple regression analysis (stepwise variable selection method) was performed with the SMR of colon cancer as the objective variable and intake of DF, nutrients, and food groups in 1966 as the explanatory variables. The beta regression coefficient was significantly positive for intakes of fat, protein, and vitamin C and significantly negative for intakes of calcium and vitamin A to the SMR of colon cancer. However, no significant correlation was observed for DF or for any of the various food groups analyzed. In conclusion, our data do not demonstrate any protective effect of DF on colon cancer in subjects with a low fat intake (Japanese subjects), which supports Fuchs' findings in subjects with high fat intake (U.S. subjects).

  13. Relationship between efficiency and clinical effectiveness indicators in an adjusted model of resource consumption: a cross-sectional study

    PubMed Central

    2013-01-01

    Background Adjusted clinical groups (ACG®) have been widely used to adjust resource distribution; however, the relationship with effectiveness has been questioned. The purpose of the study was to measure the relationship between efficiency assessed by ACG® and a clinical effectiveness indicator in adults attended in Primary Health Care Centres (PHCs). Methods Research design: cross-sectional study. Subjects: 196, 593 patients aged >14 years in 13 PHCs in Catalonia (Spain). Measures: Age, sex, PHC, basic care team (BCT), visits, episodes (diagnoses), and total direct costs of PHC care and co-morbidity as measured by ACG® indicators: Efficiency indices for costs, visits, and episodes (costs EI, visits EI, episodes EI); a complexity or risk index (RI); and effectiveness measured by a general synthetic index (SI). The relationship between EI, RI, and SI in each PHC and BCT was measured by multiple correlation coefficients (r). Results In total, 56 of the 106 defined ACG® were present in the study population, with five corresponding to 44.5% of the patients, 11 to 68.0% of patients, and 30 present in less than 0.5% of the sample. The RI in each PHC ranged from 0.9 to 1.1. Costs, visits, and episodes had similar trends for efficiency in six PHCs. There was moderate correlation between costs EI and visits EI (r = 0.59). SI correlation with episodes EI and costs EI was moderate (r = 0.48 and r = −0.34, respectively) and was r = −0.14 for visits EI. Correlation between RI and SI was r = 0.29. Conclusions The Efficiency and Effectiveness ACG® indicators permit a comparison of primary care processes between PHCs. Acceptable correlation exists between effectiveness and indicators of efficiency in episodes and costs. PMID:24139144

  14. abo-cross: Hydrogen broadening cross-section calculator

    NASA Astrophysics Data System (ADS)

    Barklem, P. S.; Anstee, S. D.; O'Mara, B. J.

    2015-07-01

    Line broadening cross sections for the broadening of spectral lines by collisions with neutral hydrogen atoms have been tabulated by Anstee & O'Mara (1995), Barklem & O'Mara (1997) and Barklem, O'Mara & Ross (1998) for s-p, p-s, p-d, d-p, d-f and f-d transitions. abo-cross, written in Fortran, interpolates in these tabulations to make these data more accessible to the end user. This code can be incorporated into existing spectrum synthesis programs or used it in a stand-alone mode to compute line broadening cross sections for specific transitions.

  15. Effect of media use on HIV-related stigma in Sub-Saharan Africa: a cross-sectional study.

    PubMed

    Bekalu, Mesfin Awoke; Eggermont, Steven; Ramanadhan, Shoba; Viswanath, Kasisomayajula

    2014-01-01

    It is known that HIV-related stigma hinders prevention efforts. Previous studies have documented that HIV-related stigma may be associated with socioeconomic and socioecological factors. Mass media use may moderate this association, but there is limited research addressing that possibility. In this study, based on cross-sectional data pooled from the 2006-2011 Demographic and Health Surveys of 11 sub-Saharan African countries (N = 204,343), we investigated the moderating effects of exposure to mass media on HIV-related stigma. Hierarchical regression analysis indicated that HIV-related stigma tends to be higher among rural residents and individuals with low levels of education and HIV knowledge, as well as those who do not know people living with HIV. Media use was generally associated with low levels of HIV-related stigma, and attenuated the gap between individuals with high and low educational levels. However, the effect of mass media was found to be stronger among urbanites rather than among rural residents, which could lead to a widening gap between the two groups in endorsement of HIV-related stigma. The implication of this study regarding the effect of media use on HIV-related stigma in sub-Saharan Africa is twofold: 1) mass media may have the potential to minimize the gap in HIV-related stigma between individuals with high and low educational levels, and hence future efforts of reducing HIV-related stigma in the region may benefit from utilizing media; 2) due perhaps to low media penetration to rural sub-Saharan Africa, mass media could have the unintended effect of widening the urban-rural gap further unless other more customized and rural-focused communication interventions are put in place.

  16. About the Effect of Control on Flutter and Post-Flutter of a Supersonic/Hypersonic Cross-Sectional Wing

    NASA Technical Reports Server (NTRS)

    Silva, Walter A.; Librescu, Liviu; Marzocca, Piergiovanni

    2001-01-01

    The control of the flutter instability and the conversion of the dangerous character of the flutter instability boundary into the undangerous one of a cross-sectional wing in a supersonic/hypersonic flow field is presented. The objective of this paper is twofold: i) to analyze the implications of nonlinear unsteady aerodynamics and physical nonlinearities on the character of the instability boundary in the presence of a control capability, and ii) to outline the effects played in the same respect by some important parameters of the aeroelastic system. As a by-product of this analysis, the implications of the active control on the linearized flutter behavior of the system are captured and emphasized. The bifurcation behavior of the open/closed loop aeroelastic system in the vicinity of the flutter boundary is studied via the use of a new methodology based on the Liapunov First Quantity. The expected outcome of this study is: a) to greatly enhance the scope and reliability of the aeroelastic analysis and design criteria of advanced supersonic/hypersonic flight vehicles and, b) provide a theoretical basis for the analysis of more complex nonlinear aeroelastic systems.

  17. About the Effect of Control on Flutter and Post-Flutter of a Supersonic/Hypersonic Cross-Sectional Wing

    NASA Technical Reports Server (NTRS)

    Marzocca, Piergiovanni; Librescu, Liviu; Silva, Walter A.

    2000-01-01

    The control of the flutter instability and the conversion of the dangerous character of the flutter instability boundary into the undangerous one of a cross-sectional wing in a supersonic/hypersonic flow field is presented. The objective of this paper is twofold: i) to analyze the implications of nonlinear unsteady aerodynamics and physical nonlinearities on the character of the instability boundary in the presence of a control capability, and ii) to outline the effects played in the same respect by some important parameters of the aeroelastic system. As a by-product of this analysis, the implications of the active control on the linearized flutter behavior of the system are captured and emphasized. The bifurcation behavior of the open/closed loop aeroelastic system in the vicinity of the flutter boundary is studied via the use of a new methodology based on the Liapunov First Quantity. The expected outcome of this study is: a) to greatly enhance the scope and reliability of the aeroelastic analysis and design criteria of advanced supersonic/hypersonic flight vehicles and, b) provide a theoretical basis for the analysis of more complex nonlinear aeroelastic systems.

  18. Geometrical and band-structure effects on phonon-limited hole mobility in rectangular cross-sectional germanium nanowires

    SciTech Connect

    Tanaka, H. Mori, S.; Morioka, N.; Suda, J.; Kimoto, T.

    2014-12-21

    We calculated the phonon-limited hole mobility in rectangular cross-sectional [001], [110], [111], and [112]-oriented germanium nanowires, and the hole transport characteristics were investigated. A tight-binding approximation was used for holes, and phonons were described by a valence force field model. Then, scattering probability of holes by phonons was calculated taking account of hole-phonon interaction atomistically, and the linearized Boltzmann's transport equation was solved to calculate the hole mobility at low longitudinal field. The dependence of the hole mobility on nanowire geometry was analyzed in terms of the valence band structure of germanium nanowires, and it was found that the dependence was qualitatively reproduced by considering an average effective mass and the density of states of holes. The calculation revealed that [110] germanium nanowires with large height along the [001] direction show high hole mobility. Germanium nanowires with this geometry are also expected to exhibit high electron mobility in our previous work, and thus they are promising for complementary metal-oxide-semiconductor (CMOS) applications.

  19. Reduction Methods for Total Reaction Cross Sections

    NASA Astrophysics Data System (ADS)

    Gomes, P. R. S.; Mendes Junior, D. R.; Canto, L. F.; Lubian, J.; de Faria, P. N.

    2016-03-01

    The most frequently used methods to reduce fusion and total reaction excitation functions were investigated in a very recent paper Canto et al. (Phys Rev C 92:014626, 2015). These methods are widely used to eliminate the influence of masses and charges in comparisons of cross sections for weakly bound and tightly bound systems. This study reached two main conclusions. The first is that the fusion function method is the most successful procedure to reduce fusion cross sections. Applying this method to theoretical cross sections of single channel calculations, one obtains a system independent curve (the fusion function), that can be used as a benchmark to fusion data. The second conclusion was that none of the reduction methods available in the literature is able to provide a universal curve for total reaction cross sections. The reduced single channel cross sections keep a strong dependence of the atomic and mass numbers of the collision partners, except for systems in the same mass range. In the present work we pursue this problem further, applying the reduction methods to systems within a limited mass range. We show that, under these circumstances, the reduction of reaction data may be very useful.

  20. Activation evaluation and isotopic effects in the (n, p) reaction cross section on A-180 target nuclei

    SciTech Connect

    Avrigeanu, M.; Forrest, R. A.; Roman, F. L.; Avrigeanu, V.

    2006-07-01

    The fast-neutron nuclear data for the stable isotopes of tungsten, tantalum and hafnium, which are important in nuclear technology applications, have been consistently analyzed by means of the nuclear model computer codes TALYS, EMPIRE-II and STAPRE-H. The latter code uses a unique parameter set. The long-lived Hf isomers, which could be produced after a few reactions on W and Ta in the first-wall material of fusion power plants, need special consideration. The analysis, making use of global as well as local parameters within different model assumptions, aims to increase the predictive power of the models, which is of interest to basic as well as applied questions. This work suggests a physical reason for some of the discrepancies between experimental and calculated cross sections for (n, p) and (n, {alpha}) reactions on {sup 181}Ta. Thus, the rather similar Q-values for the (n, p) reaction on the {sup 179}Hf, {sup 181}Ta, and {sup 183}W odd-A target nuclei, also with similar asymmetry-parameter values, support the comparable cross sections which are predicted by all three computer code calculations at variance with the lower measured cross sections of the {sup 181}Ta(n, p) {sup 181}Hf reaction. (authors)

  1. Prospects for Precision Neutrino Cross Section Measurements

    SciTech Connect

    Harris, Deborah A.

    2016-01-28

    The need for precision cross section measurements is more urgent now than ever before, given the central role neutrino oscillation measurements play in the field of particle physics. The definition of precision is something worth considering, however. In order to build the best model for an oscillation experiment, cross section measurements should span a broad range of energies, neutrino interaction channels, and target nuclei. Precision might better be defined not in the final uncertainty associated with any one measurement but rather with the breadth of measurements that are available to constrain models. Current experience shows that models are better constrained by 10 measurements across different processes and energies with 10% uncertainties than by one measurement of one process on one nucleus with a 1% uncertainty. This article describes the current status of and future prospects for the field of precision cross section measurements considering the metric of how many processes, energies, and nuclei have been studied.

  2. The cross section for double Compton scattering

    NASA Technical Reports Server (NTRS)

    Gould, R. J.

    1984-01-01

    Employing elementary methods in nonrelativistic quantum electrodynamics, the cross section for gamma sub 0 + e yields e + gamma + gamma is computed for arbitrary energy in the spectrum of the outgoing photons. The final result is given, differential in the energy of one of these photons, for the case where the incident photon is unpolarized and has energy E sub 0 much less than mc-squared, a polarization sum and angular integration being performed for the final-state photons. The cross section has a simple algebraic form resulting from contributions from the sum of squared direct and exchange amplitudes; interference terms from these amplitudes do not contribute to the angular-integrated cross section.

  3. Intraclass correlation and design effect in BMI, physical activity and diet: a cross-sectional study of 56 countries

    PubMed Central

    Masood, Mohd; Reidpath, Daniel D

    2016-01-01

    Objectives Measuring the intraclass correlation coefficient (ICC) and design effect (DE) may help to modify the public health interventions for body mass index (BMI), physical activity and diet according to geographic targeting of interventions in different countries. The purpose of this study was to quantify the level of clustering and DE in BMI, physical activity and diet in 56 low-income, middle-income and high-income countries. Design Cross-sectional study design. Setting Multicountry national survey data. Methods The World Health Survey (WHS), 2003, data were used to examine clustering in BMI, physical activity in metabolic equivalent of task (MET) and diet in fruits and vegetables intake (FVI) from low-income, middle-income and high-income countries. Multistage sampling in the WHS used geographical clusters as primary sampling units (PSU). These PSUs were used as a clustering or grouping variable in this analysis. Multilevel intercept only regression models were used to calculate the ICC and DE for each country. Results The median ICC (0.039) and median DE (1.82) for BMI were low; however, FVI had a higher median ICC (0.189) and median DE (4.16). For MET, the median ICC was 0.141 and median DE was 4.59. In some countries, however, the ICC and DE for BMI were large. For instance, South Africa had the highest ICC (0.39) and DE (11.9) for BMI, whereas Uruguay had the highest ICC (0.434) for MET and Ethiopia had the highest ICC (0.471) for FVI. Conclusions This study shows that across a wide range of countries, there was low area level clustering for BMI, whereas MET and FVI showed high area level clustering. These results suggested that the country level clustering effect should be considered in developing preventive approaches for BMI, as well as improving physical activity and healthy diets for each country. PMID:26743697

  4. The effects of insomnia and internet addiction on depression in Hong Kong Chinese adolescents: an exploratory cross-sectional analysis.

    PubMed

    Cheung, Lee M; Wong, Wing S

    2011-06-01

    The negative association of insomnia and internet addiction with mental health is widely documented in the literature, yet little is known about their inter-relationships. The primary aim of this study was to examine the inter-relationships between insomnia, internet addiction and depression. A total of 719 Chinese adolescents in Hong Kong participated in this school-based cross-sectional study. Participants completed the Chinese version of the Pittsburgh Sleep Quality Index (PSQI), the Chinese Internet Addiction Scale (CIAS), the 12-item version of General Health Questionnaire (GHQ-12) and questions assessing internet use pattern and sociodemographic characteristics. The classification of internet addiction and insomnia was based on the CIAS cutoff global score >63 and PSQI cutoff global score >5, respectively. Multiple regression analyses tested the effects of insomnia and internet addiction on depression. Among students with internet addiction (17.2%), 51.7% were also identified as insomniacs. Internet addicts scored significantly poorer on all PSQI components, except sleep duration, than their non-addicted counterparts. After adjustment for gender and internet use time, both internet addiction (β=0.05; Sobel test Z=6.50, P<0.001) and insomnia (β=0.59; Sobel test Z=4.49, P<0.001) demonstrated a significant association with depression. Overall, there is high comorbidity between internet addiction and insomnia. Both insomnia and internet addiction emerged as significant explanatory factors, but they exerted differential effects on depression. Future research should be directed at determining the causal relationship between internet addiction and insomnia, and its underlying mechanism with depression.

  5. Optical Model and Cross Section Uncertainties

    SciTech Connect

    Herman,M.W.; Pigni, M.T.; Dietrich, F.S.; Oblozinsky, P.

    2009-10-05

    Distinct minima and maxima in the neutron total cross section uncertainties were observed in model calculations using spherical optical potential. We found this oscillating structure to be a general feature of quantum mechanical wave scattering. Specifically, we analyzed neutron interaction with 56Fe from 1 keV up to 65 MeV, and investigated physical origin of the minima.We discuss their potential importance for practical applications as well as the implications for the uncertainties in total and absorption cross sections.

  6. Universal Parameterization of Absorption Cross Sections

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.

    1999-01-01

    Our prior nuclear absorption cross sections model is extended for light systems (A less than or equal to 4) where either both projectile and target are light particles or one is a light particle and the other is a medium or heavy nucleus. The agreement with experiment is excellent for these cases as well. Present work in combination with our original model provides a comprehensive picture of absorption cross sections for light, medium, and heavy systems, a very valuable input for radiation protection studies.

  7. Covariance Evaluation Methodology for Neutron Cross Sections

    SciTech Connect

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

    2008-09-01

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

  8. Neutron Capture Cross Section of 239Pu

    NASA Astrophysics Data System (ADS)

    Mosby, S.; Arnold, C.; Bredeweg, T. A.; Couture, A.; Jandel, M.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Chyzh, A.; Henderson, R.; Kwan, E.; Wu, C. Y.

    2014-09-01

    The 239Pu(n,γ) cross section has been measured over the energy range 10 eV - 10 keV using the Detector for Advanced Neutron Capture Experiments (DANCE) as part of a campaign to produce precision (n,γ) measurements on 239Pu in the keV region. Fission coincidences were measured with a PPAC and used to characterize the prompt fission γ-ray spectrum in this region. The resulting spectra will be used to better characterize the fission component of another experiment with a thicker target to extend the (n,γ) cross section measurement well into the keV region.

  9. Precise neutron inelastic cross section measurements

    SciTech Connect

    Negret, Alexandru

    2012-11-20

    The design of a new generation of nuclear reactors requires the development of a very precise neutron cross section database. Ongoing experiments performed at dedicated facilities aim to the measurement of such cross sections with an unprecedented uncertainty of the order of 5% or even smaller. We give an overview of such a facility: the Gamma Array for Inelastic Neutron Scattering (GAINS) installed at the GELINA neutron source of IRMM, Belgium. Some of the most challenging difficulties of the experimental approach are emphasized and recent results are shown.

  10. New Parameterization of Neutron Absorption Cross Sections

    NASA Astrophysics Data System (ADS)

    Tripathi, Ram K.; Wilson, John W.; Cucinotta, Francis A.

    1997-06-01

    Recent parameterization of absorption cross sections for any system of charged ion collisions, including proton-nucleus collisions, is extended for neutron-nucleus collisions valid from approx. 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pairs (charged or uncharged). The parameters are associated with the physics of the problem. At lower energies, optical potential at the surface is important, and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  11. Infrared absorption cross sections of alternative CFCs

    NASA Technical Reports Server (NTRS)

    Clerbaux, Cathy; Colin, Reginald; Simon, Paul C.

    1994-01-01

    Absorption cross sections have obtained in the infrared atmospheric window, between 600 and 1500 cm(exp -1), for 10 alternative hydrohalocarbons: HCFC-22, HCFC-123, HCFC-124, HCFC-141b, HCFC-142b, HCFC-225ca, HCFC-225cb, HFC-125, HFC-134a, and HFC-152a. The measurements were made at three temperatures (287K, 270K and 253K) with a Fourier transform spectrometer operating at 0.03 cm(exp -1) apodized resolution. Integrated cross sections are also derived for use in radiative models to calculate the global warming potentials.

  12. New Parameterization of Neutron Absorption Cross Sections

    NASA Technical Reports Server (NTRS)

    Tripathi, Ram K.; Wilson, John W.; Cucinotta, Francis A.

    1997-01-01

    Recent parameterization of absorption cross sections for any system of charged ion collisions, including proton-nucleus collisions, is extended for neutron-nucleus collisions valid from approx. 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pairs (charged or uncharged). The parameters are associated with the physics of the problem. At lower energies, optical potential at the surface is important, and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  13. Cross-section adjustment techniques for BWR adaptive simulation

    NASA Astrophysics Data System (ADS)

    Jessee, Matthew Anderson

    Computational capability has been developed to adjust multi-group neutron cross-sections to improve the fidelity of boiling water reactor (BWR) modeling and simulation. The method involves propagating multi-group neutron cross-section uncertainties through BWR computational models to evaluate uncertainties in key core attributes such as core k-effective, nodal power distributions, thermal margins, and in-core detector readings. Uncertainty-based inverse theory methods are then employed to adjust multi-group cross-sections to minimize the disagreement between BWR modeling predictions and measured plant data. For this work, measured plant data were virtually simulated in the form of perturbed 3-D nodal power distributions with discrepancies with predictions of the same order of magnitude as expected from plant data. Using the simulated plant data, multi-group cross-section adjustment reduces the error in core k-effective to less than 0.2% and the RMS error in nodal power to 4% (i.e. the noise level of the in-core instrumentation). To ensure that the adapted BWR model predictions are robust, Tikhonov regularization is utilized to control the magnitude of the cross-section adjustment. In contrast to few-group cross-section adjustment, which was the focus of previous research on BWR adaptive simulation, multigroup cross-section adjustment allows for future fuel cycle design optimization to include the determination of optimal fresh fuel assembly designs using the adjusted multi-group cross-sections. The major focus of this work is to efficiently propagate multi-group neutron cross-section uncertainty through BWR lattice physics calculations. Basic neutron cross-section uncertainties are provided in the form of multi-group cross-section covariance matrices. For energy groups in the resolved resonance energy range, the cross-section uncertainties are computed using an infinitely-dilute approximation of the neutron flux. In order to accurately account for spatial and

  14. Neutron Fission of 235,237,239U and 241,243Pu: Cross Sections, Integral Cross Sections and Cross Sections on Excited States

    SciTech Connect

    Younes, W; Britt, H C

    2003-07-10

    In a recent paper submitted to Phys. Rev. C they have presented estimates for (n,f) cross sections on a series of Thorium, Uranium and Plutonium isotopes over the range E{sub n} = 0.1-2.5 MeV. The (n,f) cross sections for many of these isotopes are difficult or impossible to measure in the laboratory. The cross sections were obtained from previous (t,pf) reaction data invoking a model which takes into account the differences between (t,pf) and (n,f) reaction processes, and which includes improved estimates for the neutron compound formation process. The purpose of this note is: (1) to compare the estimated cross sections to current data files in both ENDF and ENDL databases; (2) to estimate ratios of cross sections relatively to {sup 235}U integrated over the ''tamped flattop'' critical assembly spectrum that was used in the earlier {sup 237}U report; and (3) to show the effect on the integral cross sections when the neutron capturing state is an excited rotational state or an isomer. The isomer and excited state results are shown for {sup 235}U and {sup 237}U.

  15. Systematic study of three-nucleon force effects in the cross section of the deuteron-proton breakup at 130 MeV

    SciTech Connect

    St. Kistryn; E. Stephan; A. Biegun; K. Bodek; A. Deltuva; E. Epelbaum; K. Ermisch; W. Gloeckle; J. Golak; N. Kalantar-Nayestanaki; H. Kamada; M. Kis; B. Klos; A. Kozela; J. Kuros-Zolnierczuk; M. Mahjour-Shafiei; U.-G. Meissner; A. Micherdzinska; A. Nogga; P. U. Sauer; R. Skibinski; R. Sworst; H. Witala; J. Zejma; W. Zipper

    2005-08-11

    High precision cross-section data of the deuteron-proton breakup reaction at 130 MeV are presented for 72 kinematically complete configurations. The data cover a large region of the available phase space, divided into a systematic grid of kinematical variables. They are compared with theoretical predictions, in which the full dynamics of the three-nucleon (3N) system is obtained in three different ways: realistic nucleon-nucleon (NN) potentials are combined with model 3N forces (3NF's) or with an effective 3NF resulting from explicit treatment of the Delta-isobar excitation. Alternatively, the chiral perturbation theory approach is used at the next-to-next-to-leading order with all relevant NN and 3N contributions taken into account. The generated dynamics is then applied to calculate cross-section values by rigorous solution of the 3N Faddeev equations. The comparison of the calculated cross sections with the experimental data shows a clear preference for the predictions in which the 3NF's are included. The majority of the experimental data points is well reproduced by the theoretical predictions. The remaining discrepancies are investigated by inspecting cross sections integrated over certain kinematical variables. The procedure of global comparisons leads to establishing regularities in disagreements between the experimental data and the theoretically predicted values of the cross sections. They indicate deficiencies still present in the assumed models of the 3N system dynamics.

  16. Effect of Primary Dendrite Orientation on Stray Grain Formation in Cross-Section Change Region During the Directional Solidification of Ni-Based Superalloy

    NASA Astrophysics Data System (ADS)

    Xuan, Weidong; Li, Chuantao; Zhao, Dengke; Wang, Baojun; Li, Chuanjun; Ren, Zhongming; Zhong, Yunbo; Li, Xi; Cao, Guanghui

    2017-02-01

    The effect of primary dendrite orientation on stray grain formation in a cross-section change region during the directional solidification of Ni-based superalloy is investigated through both experimental observations and numerical simulation. The results clearly show that the orientation of primary dendrite affects the formation of stray grains in the cross-section change region. It is observed that, for the primary dendrite without misorientation, no stray grain is formed in the cross-section change region; for the primary dendrite with a moderate misorientation (15 deg), stray grains are formed only on the side converging from the mold wall in the cross-section change region. When the misorientation is 25 deg, stray grains are formed on both the side converging from the mold wall and the side diverging from the mold wall in the cross-section change region (the converging side and the diverging side for short). The simulation results are in accordance with experimental results. Furthermore, the correlation among factors such as stray grain formation, primary dendrite orientation, and withdrawal velocity has been analyzed. The mechanism of stray grain formation in various oriented primary dendrites is discussed.

  17. Cotton fibre cross-section properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    From a structural perspective the cotton fibre is a singularly discrete, elongated plant cell with no junctions or inter-cellular boundaries. Its form in nature is essentially unadulterated from the field to the spinning mill where its cross-section properties, as for any textile fibre, are central ...

  18. Testing (Validating?) Cross Sections with ICSBEP Benchmarks

    SciTech Connect

    Kahler, Albert C. III

    2012-06-28

    We discuss how to use critical benchmarks from the International Handbook of Evaluated Criticality Safety Benchmark Experiments to determine the applicability of specific cross sections to the end-user's problem of interest. Particular attention is paid to making sure the selected suite of benchmarks includes the user's range of applicability (ROA).

  19. Neutron capture cross section of Am241

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-01

    The neutron capture cross section of Am241 for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665±33 b. Our result is in good agreement with other recent measurements. Resonance parameters for En<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. Γn neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553±7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  20. Cross-sectional structural parameters from densitometry

    NASA Technical Reports Server (NTRS)

    Cleek, Tammy M.; Whalen, Robert T.

    2002-01-01

    Bone densitometry has previously been used to obtain cross-sectional properties of bone from a single X-ray projection across the bone width. Using three unique projections, we have extended the method to obtain the principal area moments of inertia and orientations of the principal axes at each scan cross-section along the length of the scan. Various aluminum phantoms were used to examine scanner characteristics to develop the highest accuracy possible for in vitro non-invasive analysis of cross-sectional properties. Factors considered included X-ray photon energy, initial scan orientation, the angle spanned by the three scans (included angle), and I(min)/I(max) ratios. Principal moments of inertia were accurate to within +/-3.1% and principal angles were within +/-1 degrees of the expected value for phantoms scanned with included angles of 60 degrees and 90 degrees at the higher X-ray photon energy (140 kVp). Low standard deviations in the error (0.68-1.84%) also indicate high precision of calculated measurements with these included angles. Accuracy and precision decreased slightly when the included angle was reduced to 30 degrees. The method was then successfully applied to a pair of excised cadaveric tibiae. The accuracy and insensitivity of the algorithms to cross-sectional shape and changing isotropy (I(min)/I(max)) values when various included angles are used make this technique viable for future in vivo studies.

  1. Reaction cross section of 22C

    NASA Astrophysics Data System (ADS)

    Togano, Yasuhiro; Samurai Collaboration

    2014-09-01

    Reaction cross section of 22C on a carbon target at an energy of 240 MeV/nucleon have been measured by using the transmission method. The most neutron-rich carbon isotopes 22C is a candidate of a two-neutron halo nucleus. Tanaka et al. [1] measured the reaction cross section of 22C on a hydrogen target at 40 MeV/nucleon. It is showed 22C to have a large matter radius of 5 . 9 +/- 0 . 9 fm, which is much larger than the ones of carbon isotopes with N <= 14 , suggesting 22C is the halo nucleus. This reported radius has a large uncertainty due to a lack of statistics. To deduce a more accurate matter radius of 22C, the measurement of reaction cross section with higher statistics at a higher beam energy are required. The experiment was performed by using the SAMURAI spectrometer at RIBF. The 22C beam at 240 MeV/nucleon was impinged on a carbon target, and the reaction product was identified by using SAMURAI spectrometer. In the present talk, the extracted reaction cross section and derived matter density distribution of 22C will be presented.

  2. A practical approach to temperature effects in dissociative electron attachment cross sections using local complex potential theory

    NASA Astrophysics Data System (ADS)

    Sugioka, Yuji; Takayanagi, Toshiyuki

    2012-09-01

    We propose a practical computational scheme to obtain temperature dependence of dissociative electron attachment cross sections to polyatomic molecules within a local complex potential theory formalism. First we perform quantum path-integral molecular dynamics simulations on the potential energy surface for the neutral molecule in order to sample initial nuclear configurations as well as momenta. Classical trajectories are subsequently integrated on the potential energy surface for the anionic state and survival probabilities are simultaneously calculated along the obtained trajectories. We have applied this simple scheme to dissociative electron attachment processes to H2O and CF3Cl, for which several previous studies are available from both the experimental and theoretical sides.

  3. The effects of health worker motivation and job satisfaction on turnover intention in Ghana: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Motivation and job satisfaction have been identified as key factors for health worker retention and turnover in low- and middle-income countries. District health managers in decentralized health systems usually have a broadened ‘decision space’ that enables them to positively influence health worker motivation and job satisfaction, which in turn impacts on retention and performance at district-level. The study explored the effects of motivation and job satisfaction on turnover intention and how motivation and satisfaction can be improved by district health managers in order to increase retention of health workers. Methods We conducted a cross-sectional survey in three districts of the Eastern Region in Ghana and interviewed 256 health workers from several staff categories (doctors, nursing professionals, allied health workers and pharmacists) on their intentions to leave their current health facilities as well as their perceptions on various aspects of motivation and job satisfaction. The effects of motivation and job satisfaction on turnover intention were explored through logistic regression analysis. Results Overall, 69% of the respondents reported to have turnover intentions. Motivation (OR = 0.74, 95% CI: 0.60 to 0.92) and job satisfaction (OR = 0.74, 95% CI: 0.57 to 0.96) were significantly associated with turnover intention and higher levels of both reduced the risk of health workers having this intention. The dimensions of motivation and job satisfaction significantly associated with turnover intention included career development (OR = 0.56, 95% CI: 0.36 to 0.86), workload (OR = 0.58, 95% CI: 0.34 to 0.99), management (OR = 0.51. 95% CI: 0.30 to 0.84), organizational commitment (OR = 0.36, 95% CI: 0.19 to 0.66), and burnout (OR = 0.59, 95% CI: 0.39 to 0.91). Conclusions Our findings indicate that effective human resource management practices at district level influence health worker motivation and job satisfaction

  4. On the effects of improved cross-section representation in one-dimensional flow routing models applied to ephemeral rivers

    NASA Astrophysics Data System (ADS)

    Hutton, Christopher J.; Brazier, Richard E.; Nicholas, Andrew P.; Nearing, Mark

    2012-04-01

    Flash floods are an important component of the semiarid hydrological cycle, and provide the potential for groundwater recharge as well as posing a dangerous natural hazard. A number of catchment models have been applied to flash flood prediction; however, in general they perform poorly. This study has investigated whether the incorporation of light detection and ranging (lidar) derived data into the structure of a 1-D flow routing model can improve the prediction of flash floods in ephemeral channels. Two versions of this model, one based on an existing trapezoidal representation of cross-section morphology (K-Tr), and one that uses lidar data (K-Li) were applied to 5 discrete runoff events measured at two locations on the main channel of The Walnut Gulch Experimental Watershed, United States. In general, K-Li showed improved performance in comparison to K-Tr, both when each model was calibrated to individual events and during an evaluation phase when the models (and parameter sets) were applied across events. Sensitivity analysis identified that the K-Li model also had more consistency in behavioral parameter sets across runoff events. In contrast, parameter interaction within K-Tr resulted in poorly constrained behavioral parameter sets across the multidimensional parameter space. These results, revealed with a modeling focus on the structure of a particular element of a distributed catchment model, suggest that lidar derived cross-section morphology can lead to improved, and more robust flash flood prediction.

  5. Photo-ionization cross-section of donor-related in (In,Ga)N/GaN core/shell under hydrostatic pressure and electric field effects

    NASA Astrophysics Data System (ADS)

    El Ghazi, Haddou; John Peter, A.

    2017-04-01

    Hydrogenic-like donor-impurity related self and induced polarizations, bending energy and photo-ionization cross section in spherical core/shell zinc blende (In,Ga)N/GaN are computed. Based on the variational approach and within effective-mass and one parabolic approximations, the calculations are made under finite potential barrier taking into account of the discontinuity of the effective-mass and the constant dielectric. The photo-ionization cross section is studied according to the photon incident energy considering the effects of hydrostatic pressure, applied electric field, structure's radius, impurity's position and indium composition in the core. It is obtained that the influences mentioned above lead to either blue shifts or redshifts of the resonant peak of the photo-ionization cross section spectrum. The unusual behavior related to the structure radius is discussed which is as a consequence of the finite potential confinement. We have shown that the photo-ionization cross section can be controlled with adjusting the internal and external factors. These properties can be useful for producing some device applications such as quantum dot infrared photodetectors.

  6. Effects of different strength training frequencies during reduced training period on strength and muscle cross-sectional area.

    PubMed

    Tavares, Lucas Duarte; de Souza, Eduardo Oliveira; Ugrinowitsch, Carlos; Laurentino, Gilberto Candido; Roschel, Hamilton; Aihara, André Yui; Cardoso, Fabiano Nassar; Tricoli, Valmor

    2017-03-19

    This study investigated the effects of different reduced strength training (RST) frequencies on half-squat 1 RM and quadriceps cross-sectional area (QCSA). Thirty-three untrained males (24.7 ± 3.9 years; 1.73 ± 0.08 m; 74.6 ± 8.4 kg) underwent a 16-week experimental period (i.e. eight weeks of strength training [ST] followed by additional eight weeks of RST). During the ST period, the participants performed 3-4 sets of 6-12 RM, three sessions/week in half-squat and knee extension exercises. Following ST, the participants were randomly allocated to one of three groups: reduced strength training with one (RST1) or two sessions per week (RST2), and ceased training (CT). Both RST1 and RST2 groups had their training frequency and total training volume-load (i.e. RST1 = 50.3% and RST2 = 57.1%) reduced, while the CT group stopped training completely. Half-squat 1 RM (RST1 = 27.9%; RST2 = 26.7%; and CT = 28.4%) and QCSA (RST1 = 6.1%; RST2 = 6.9%; and CT = 5.8%) increased significantly (p < .05) in all groups after eight weeks of ST. No significant changes were observed in 1 RM and QCSA for RST1 and RST2 groups after the RST period, while the CT group demonstrated a decrease in half-squat 1 RM (22.6%) and QCSA (5.4%) when compared to the ST period (p < .05). In conclusion, different RST frequencies applied were able to maintain muscle mass and strength performance obtained over the regular ST period. Thus, it appears that RST frequency does not affect the maintenance of muscle mass and strength in untrained males, as long as volume-load is equated between frequencies.

  7. Relativistic corrections in K-shell ionization cross sections

    SciTech Connect

    Sheth, C.V.

    1984-03-01

    Relativistic effects on a modified version of Rutherford's scattering cross section are considered up to first-order in the Born approximation for relativistic velocities in the binary-encounter approximation (BEA). The predicted cross sections with protons as projectile are lower than the previous theoretical values at low energies and are seen to be in better agreement with measurements. An approximate relativistic correction factor which accounts for orbital electrons only is compared with exact Dirac corrections, within the BEA model.

  8. Absolute np and pp cross section determinations aimed at improving the standard for cross section measurements

    SciTech Connect

    Laptev, Alexander B; Haight, Robert C; Tovesson, Fredrik; Arndt, Richard A; Briscoe, William J; Paris, Mark W; Strakovsky, Igor I; Workman, Ron L

    2010-01-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PW As) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-V11.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  9. Absolute np and pp Cross Section Determinations Aimed At Improving The Standard For Cross Section Measurements

    SciTech Connect

    Laptev, A. B.; Haight, R. C.; Tovesson, F.; Arndt, R. A.; Briscoe, W. J.; Paris, M. W.; Strakovsky, I. I.; Workman, R. L.

    2011-06-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1 GeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  10. Tables of nuclear cross sections for galactic cosmic rays: Absorption cross sections

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    A simple but comprehensive theory of nuclear reactions is presented. Extensive tables of nucleon, deuteron, and heavy-ion absorption cross sections over a broad range of energies are generated for use in cosmic ray shielding studies. Numerous comparisons of the calculated values with available experimental data show agreement to within 3 percent for energies above 80 MeV/nucleon and within approximately 10 percent for energies as low as 30 MeV/nucleon. These tables represent the culmination of the development of the absorption cross section formalism and supersede the preliminary absorption cross sections published previously in NASA TN D-8107, NASA TP-2138, and NASA TM-84636.

  11. Tables of nuclear cross sections for galactic cosmic rays: Absorption cross sections

    NASA Astrophysics Data System (ADS)

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

    1985-05-01

    A simple but comprehensive theory of nuclear reactions is presented. Extensive tables of nucleon, deuteron, and heavy-ion absorption cross sections over a broad range of energies are generated for use in cosmic ray shielding studies. Numerous comparisons of the calculated values with available experimental data show agreement to within 3 percent for energies above 80 MeV/nucleon and within approximately 10 percent for energies as low as 30 MeV/nucleon. These tables represent the culmination of the development of the absorption cross section formalism and supersede the preliminary absorption cross sections published previously in NASA TN D-8107, NASA TP-2138, and NASA TM-84636.

  12. Extinction cross section of a dielectric strip

    NASA Astrophysics Data System (ADS)

    Dowerah, Subratananda; Chakrabarti, Aloknath

    1988-05-01

    The problem of scattering of a plane electromagnetic wave by a dielectric strip is formulated in terms of an uncoupled system of three-part Wiener-Hopf equations by using a set of approximate boundary conditions derived and utilized recently. The resulting Wiener-Hopf problems are solved approximately for sufficiently large values of the width of the strip by using Jones' method (1964). An analytical formula is derived for the excitation cross section of the strip under consideration from which numerical values are obtained in specific situations and the results are presented graphically. The radar cross section of the strip is also computed for several special circumstances and these are presented separately.

  13. Rotational averaging of multiphoton absorption cross sections

    NASA Astrophysics Data System (ADS)

    Friese, Daniel H.; Beerepoot, Maarten T. P.; Ruud, Kenneth

    2014-11-01

    Rotational averaging of tensors is a crucial step in the calculation of molecular properties in isotropic media. We present a scheme for the rotational averaging of multiphoton absorption cross sections. We extend existing literature on rotational averaging to even-rank tensors of arbitrary order and derive equations that require only the number of photons as input. In particular, we derive the first explicit expressions for the rotational average of five-, six-, and seven-photon absorption cross sections. This work is one of the required steps in making the calculation of these higher-order absorption properties possible. The results can be applied to any even-rank tensor provided linearly polarized light is used.

  14. Rotational averaging of multiphoton absorption cross sections.

    PubMed

    Friese, Daniel H; Beerepoot, Maarten T P; Ruud, Kenneth

    2014-11-28

    Rotational averaging of tensors is a crucial step in the calculation of molecular properties in isotropic media. We present a scheme for the rotational averaging of multiphoton absorption cross sections. We extend existing literature on rotational averaging to even-rank tensors of arbitrary order and derive equations that require only the number of photons as input. In particular, we derive the first explicit expressions for the rotational average of five-, six-, and seven-photon absorption cross sections. This work is one of the required steps in making the calculation of these higher-order absorption properties possible. The results can be applied to any even-rank tensor provided linearly polarized light is used.

  15. {sup 231}Pa photofission cross section

    SciTech Connect

    Soldatov, A.S.; Rudnikov, V.E.; Smirenkin, G.N.

    1995-12-01

    The measurements of the {sup 231}Pa yield and cross section photofission in the energy range 7-9 MeV are presented. These measurements are a continuation of similar measurements performed for the {gamma}-ray energy range 4.8-7 MeV. The entire collection of experimental data which combine the results obtained in the present work and in Ref. 1 was analyzed.

  16. How to Calculate Colourful Cross Sections Efficiently

    SciTech Connect

    Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank

    2008-09-03

    Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

  17. Fusion cross sections measurements with MUSIC

    NASA Astrophysics Data System (ADS)

    Carnelli, P. F. F.; Fernández Niello, J. O.; Almaraz-Calderon, S.; Rehm, K. E.; Albers, M.; Digiovine, B.; Esbensen, H.; Henderson, D.; Jiang, C. L.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Ugalde, C.; Paul, M.; Alcorta, M.; Bertone, P. F.; Lai, J.; Marley, S. T.

    2014-09-01

    The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. This work is supported by the U.S. DOE Office of Nuclear Physics under Contract No. DE-AC02-06CH11357 and the Universidad Nacional de San Martin, Argentina, Grant SJ10/39.

  18. Fusion cross sections and the new dynamics

    SciTech Connect

    Swiatecki, W.J.

    1981-05-01

    The prediction of the need for an extra push over the interaction barrier in order to make the heavier nuclei fuse is made the basis of a simple algebraic theory for the energy-dependence of the fusion cross-section. A comparison with recent experiments promises to provide a quantitative test of the New Dynamics (the theory of macroscopic nuclear shape evolutions based on the one-body dissipation concept).

  19. Inclusive jet cross section measurement at CDF

    SciTech Connect

    Pagliarone, C.

    1996-08-01

    The CDF Collaboration has measured the inclusive jet cross section using 1992-93 collider data at 1.8 TeV. The CDF measurement is in very good agreement with NLO QCD predictions for transverse energies (E{sub T}) below 200 GeV. However, it is systematically higher than NLO QCD predictions for E{sub T} above 200 GeV.

  20. Nanoscale size effects on the mechanical properties of platinum thin films and cross-sectional grain morphology

    NASA Astrophysics Data System (ADS)

    Abbas, K.; Alaie, S.; Ghasemi Baboly, M.; Elahi, M. M. M.; Anjum, D. H.; Chaieb, S.; Leseman, Z. C.

    2016-01-01

    The mechanical behavior of polycrystalline Pt thin films is reported for thicknesses of 75 nm, 100 nm, 250 nm, and 400 nm. These thicknesses correspond to transitions between nanocrystalline grain morphology types as found in TEM studies. Thinner samples display a brittle behavior, but as thickness increases the grain morphology evolves, leading to a ductile behavior. During evolution of the morphology, dramatic differences in elastic moduli (105-160 GPa) and strengths (560-1700 MPa) are recorded and explained by the variable morphology. This work suggests that in addition to the in-plane grain size of thin films, the transitions in cross-sectional morphologies of the Pt films significantly affect their mechanical behavior.

  1. Quality Quantification of Evaluated Cross Section Covariances

    SciTech Connect

    Varet, S.; Dossantos-Uzarralde, P.

    2015-01-15

    Presently, several methods are used to estimate the covariance matrix of evaluated nuclear cross sections. Because the resulting covariance matrices can be different according to the method used and according to the assumptions of the method, we propose a general and objective approach to quantify the quality of the covariance estimation for evaluated cross sections. The first step consists in defining an objective criterion. The second step is computation of the criterion. In this paper the Kullback-Leibler distance is proposed for the quality quantification of a covariance matrix estimation and its inverse. It is based on the distance to the true covariance matrix. A method based on the bootstrap is presented for the estimation of this criterion, which can be applied with most methods for covariance matrix estimation and without the knowledge of the true covariance matrix. The full approach is illustrated on the {sup 85}Rb nucleus evaluations and the results are then used for a discussion on scoring and Monte Carlo approaches for covariance matrix estimation of the cross section evaluations.

  2. Total cross sections for ultracold neutrons scattered from gases

    DOE PAGES

    Seestrom, Susan Joyce; Adamek, Evan R.; Barlow, Dave; ...

    2017-01-30

    Here, we have followed up on our previous measurements of upscattering of ultracold neutrons (UCNs) from a series of gases by making measurements of total cross sections on the following gases hydrogen, ethane, methane, isobutene, n-butane, ethylene, water vapor, propane, neopentane, isopropyl alcohol, and 3He. The values of these cross sections are important for estimating the loss rate of trapped neutrons due to residual gas and are relevant to neutron lifetime measurements using UCNs. The effects of the UCN velocity and path-length distributions were accounted for in the analysis using a Monte Carlo transport code. Results are compared to ourmore » previous measurements and with the known absorption cross section for 3He scaled to our UCN energy. We find that the total cross sections for the hydrocarbon gases are reasonably described by a function linear in the number of hydrogen atoms in the molecule.« less

  3. Total cross sections for ultracold neutrons scattered from gases

    NASA Astrophysics Data System (ADS)

    Seestrom, S. J.; Adamek, E. R.; Barlow, D.; Blatnik, M.; Broussard, L. J.; Callahan, N. B.; Clayton, S. M.; Cude-Woods, C.; Currie, S.; Dees, E. B.; Fox, W.; Hoffbauer, M.; Hickerson, K. P.; Holley, A. T.; Liu, C.-Y.; Makela, M.; Medina, J.; Morley, D. J.; Morris, C. L.; Pattie, R. W.; Ramsey, J.; Roberts, A.; Salvat, D. J.; Saunders, A.; Sharapov, E. I.; Sjue, S. K. L.; Slaughter, B. A.; Walstrom, P. L.; Wang, Z.; Wexler, J.; Womack, T. L.; Young, A. R.; Vanderwerp, J.; Zeck, B. A.

    2017-01-01

    We have followed up on our previous measurements of upscattering of ultracold neutrons (UCNs) from a series of gases by making measurements of total cross sections on the following gases hydrogen, ethane, methane, isobutene, n -butane, ethylene, water vapor, propane, neopentane, isopropyl alcohol, and 3He . The values of these cross sections are important for estimating the loss rate of trapped neutrons due to residual gas and are relevant to neutron lifetime measurements using UCNs. The effects of the UCN velocity and path-length distributions were accounted for in the analysis using a Monte Carlo transport code. Results are compared to our previous measurements and with the known absorption cross section for 3He scaled to our UCN energy. We find that the total cross sections for the hydrocarbon gases are reasonably described by a function linear in the number of hydrogen atoms in the molecule.

  4. Absolute and relative surrogate measurements of the uranium-236(n,f) cross section as a probe of angular momentum effects

    NASA Astrophysics Data System (ADS)

    Lyles, Bethany Faye

    The absolute surrogate technique and the Surrogate Ratio Method (SRM) were used to deduce the 236U(n,f) cross section over an equivalent neutron energy range of 0.1 to 20 MeV for the absolute measurement and 0.8 to 20 MeV for the relative measurement. A 42 MeV 3He2+ beam from the 88--Inch Cyclotron at Lawrence Berkeley National Laboratory was used to perform a (3He,alpha) pickup reaction on targets of 235U (Jpi=7/2 --) and 238U (Jpi=0+) and the fission decay probabilities were determined. The 235U( 3He,alphaf) and 238U(3He,alphaf) reactions were surrogates for 233U(n,f) and 236U(n,f), respectively. Using the absolute surrogate technique, the experimentally determined 238U(3He,alpha) fission probability was multiplied by a calculated neutron absorption cross section to obtain the 236 U(n,f) cross section. Using the SRM, a ratio of the experimentally determined fission probabilities, 238U(3He,alphaf) to 235U(3He,alphaf), was extracted and multiplied by the evaluated 233U(n,f) cross section to obtain the 236U(n,f) cross section. Neither the absolute surrogate nor the SRM used in this case explicitly accounted for Jpi-dependence of the fission probabilities. The cross sections extracted using the Surrogate Method were compared to directly measured cross sections and theoretical predictions. The absolute surrogate 236U(n,f) cross section trended well with the evaluated nuclear data below 3.3 MeV, but was beset with target contamination above this energy, whereas the SRM result agreed with the evaluated nuclear data to within 10% at neutron energies from 3.5 to 20 MeV and exhibited significant deviations in the low energy regime. The deduced surrogate 236U(n,f) cross section was determined as a function of the angle of the alpha particle ejectile in the direct reaction to explore different angular momentum population distributions in the compound nucleus and their effects on the extracted fission probabilities. The 236U(n,f) cross sections extracted using both the

  5. [THE USING OF THE METHOD OF RECONSTRUCTION OF OPTICAL CROSS SECTIONS FOR INVESTIGATION OF THE TROPHOTROPIC EFFECTS OF ADRENALINE AND ATENOLOL].

    PubMed

    Lopatina, E V; Kipenko, A V; Penniyaynen, V A; Pasatetskaya, N A; Tsyrline, V A

    2015-09-01

    The trophotropic effects of epinephrine and atenolol were investigated by using the organotypic culture method combined with the method of the reconstruction of optical cross sections. For the best possible image contrast was experimentally established the correction for Petri dish bottom thickness equal to 1 mm (objective lens Carl Zeiss). It was shown by method of the reconstruction of optical cross sections that growth zone in organotypic culture forms a multidimensional structure. In the presence of atenolol (10(-4) M) the thickness of the growth zone of the cardiac tissue explants was above the reference value 212%. The thickness of the growth zone in the presence of epinephrine (10(-9)-10(-13) M) did not differ from the control values. Experimentally was proved that atenolol mimics the trophotropic effects of epinephrine and these effects of epinephrine is realized primarily through β1-adrenergic receptors.

  6. Neutron Capture Cross Section Calculations with the Statistical Model

    NASA Astrophysics Data System (ADS)

    Beard, Mary; Uberseder, Ethan; Wiescher, Michael

    2014-09-01

    Hauser-Feshbach (HF) cross sections are of enormous importance for a wide range of applications, from waste transmutation and nuclear technologies, to medical applications, and nuclear astrophysics. It is a well observed result that different nuclear input models sensitively affect HF cross section calculations. Less well-known however are the effects on calculations originating from model-specific implementation details (such as level density parameter, matching energy, backshift and giant dipole parameters), as well as effects from non-model aspects, such as experimental data truncation and transmission function energy binning. To investigate the effects or these various aspects, Maxwellian-averaged neutron capture cross sections have been calculated for approximately 340 nuclei. The relative effects of these model details will be discussed.

  7. Preliminary cross section of Englebright Lake sediments

    USGS Publications Warehouse

    Snyder, Noah P.; Hampton, Margaret A.

    2003-01-01

    Overview -- The Upper Yuba River Studies Program is a CALFED-funded, multidisciplinary investigation of the feasibility of introducing anadromous fish species to the Yuba River system upstream of Englebright Dam. Englebright Lake (Figure 1 on poster) is a narrow, 14-km-long reservoir located in the northern Sierra Nevada, northeast of Marysville, CA. The dam was completed in 1941 for the primary purpose of trapping sediment derived from mining operations in the Yuba River watershed. Possible management scenarios include lowering or removing Englebright Dam, which could cause the release of stored sediments and associated contaminants, such as mercury used extensively in 19th-century hydraulic gold mining. Transport of released sediment to downstream areas could increase existing problems including flooding and mercury bioaccumulation in sport fish. To characterize the extent, grain size, and chemistry of this sediment, a coring campaign was done in Englebright Lake in May and June 2002. More than twenty holes were drilled at 7 different locations along the longitudinal axis of the reservoir (Figure 4 on poster), recovering 6 complete sequences of post-reservoir deposition and progradation. Here, a longitudinal cross section of Englebright Lake is presented (Figure 5 on poster), including pre-dam and present-day topographic profiles, and sedimentologic sections for each coring site. This figure shows the deltaic form of the reservoir deposit, with a thick upper section consisting of sand and gravel overlying silt, a steep front, and a thinner lower section dominated by silt. The methodologies used to create the reservoir cross section are discussed in the lower part of this poster.

  8. Averaging cross section data so we can fit it

    SciTech Connect

    Brown, D.

    2014-10-23

    The 56Fe cross section we are interested in have a lot of fluctuations. We would like to fit the average of the cross section with cross sections calculated within EMPIRE. EMPIRE is a Hauser-Feshbach theory based nuclear reaction code, requires cross sections to be smoothed using a Lorentzian profile. The plan is to fit EMPIRE to these cross sections in the fast region (say above 500 keV).

  9. Nuclear interaction cross sections for proton radiotherapy

    NASA Astrophysics Data System (ADS)

    Chadwick, M. B.; Jones, D. T. L.; Arendse, G. J.; Cowley, A. A.; Richter, W. A.; Lawrie, J. J.; Newman, R. T.; Pilcher, J. V.; Smit, F. D.; Steyn, G. F.; Koen, JW; Stander, JA

    Model calculations of proton-induced nuclear reaction cross sections are described for biologically-important targets. Measurements made at the National Accelerator Centre are presented for double-differential proton, deuteron, triton, helium-3 and alpha particle spectra, for 150 and 200 MeV protons incident on C, N, and O. These data are needed for Monte Carlo simulations of radiation transport and absorbed dose in proton therapy. Data relevant to the use of positron emission tomography to locate the Bragg peak are also described.

  10. Critical behavior of cross sections at LHC

    NASA Astrophysics Data System (ADS)

    Dremin, I. M.

    2016-07-01

    Recent experimental data on elastic scattering of high energy protons show that the critical regime has been reached at LHC energies. The approach to criticality is demonstrated by increase of the ratio of elastic to total cross sections from ISR to LHC energies. At LHC it reaches the value which can result in principal change of the character of proton interactions. The treatment of new physics of hollowed toroid-like hadrons requires usage of another branch of the unitarity condition. Its further fate is speculated and interpreted with the help of the unitarity condition in combination with present experimental data. The gedanken experiments to distinguish between different possibilities are proposed.

  11. Neutron absorption cross section of uranium-236

    SciTech Connect

    Macklin, R.L.; Alexander, C.W.

    1988-11-01

    U-236 neutron absorption was measured as a function of neutron time-of-flight from 20 eV to 1 MeV. The neutron flux was monitored with a /sup 6/Li glass scintillator. Average cross sections from 3 keV to 1 MeV were derived. Estimated uncertainties were less than 5% below 600 keV and increased to 9.5% at 1 MeV. Resonance parametrization from 20 eV to a few keV remains to be done. 17 refs., 5 figs., 3 tabs.

  12. Cross-sectional nanoindentation (CSN) studies on the effect of thickness on adhesion strength of thin films

    NASA Astrophysics Data System (ADS)

    Roshanghias, A.; Khatibi, G.; Pelzer, R.; Steinbrenner, J.; Bernardi, J.

    2015-01-01

    In this study the cross-sectional nanoindentation (CSN) technique has been employed to investigate the adhesion behavior of Titanium-Tungsten (TiW) thin films in various thicknesses on silicon substrate. Furthermore, the nanoindentation-induced blister (NIB) technique has been implemented on the same samples to evaluate the adhesion energy of the films with a different approach. The adhesion energy release rate of these thin films, derived by these two techniques, revealed a good agreement. Accordingly, the results show that as the thickness of the TiW layer increases, the adhesion toughness of the film decreases. It was suggested that three factors might be responsible for the superior adhesion strength of thin films with lower thicknesses: higher surface energy due to the smaller mean grain size; higher constraint from the substrate, which causes inferior fracture toughness of the coating and facilitates crack deflection from interface to surface; and, energy dissipation due to decohesion. The thickness dependency of the transition between delamination and decohesion mechanism in thin films has also been discussed and modelled.

  13. The effect of the dipole bound state on AgF- vibrationally resolved photodetachment cross sections and photoelectron angular distributions

    NASA Astrophysics Data System (ADS)

    Dao, Diep Bich; Mabbs, Richard

    2014-10-01

    The first photoelectron spectra of AgF- are recorded over the energy range 1.61-1.85 eV using the velocity map imaging technique. The resolved vibrational structure of the AgF X', v' ← AgF- X″, v″ = 0 band yields an AgF electron affinity of 1.46 ± 0.01 eV and vibrational frequency of 500 ± 40 cm-1. For the v' = 2, 3, 4 channels, the photodetachment cross sections and angular distributions undergo rapid changes over a narrow electron kinetic energy range in the region of 50 meV (approximately 13 meV below the opening of the next vibrational channel). This is consistent with Fano-like behavior indicating autodetachment following excitation to a resonant anion state lying in the detachment continuum. EOM-CCSD calculations reveal this to be a dipole bound state. The consistency of the detachment data with the vibrational autodetachment propensity rule Δv = -1 shows that the autodetachment results from breakdown of the Born-Oppenheimer approximation, coupling the vibrational and electronic degrees of freedom.

  14. Effect of time of exposure to environmental risk on the lung function of foundry workers: a cross-sectional study

    PubMed Central

    Vasconcelos de Moraes, Mônica; Padula, Rosimeire Simprini; Bernardes, Rosane Andrea Bretas; Negreiros, Alexandher; Chiavegato, Luciana Dias

    2016-01-01

    [Purpose] This cross-sectional study aimed to compare foundry workers of the metallurgical industry with high and low exposure time and with a control group. [Subject and Methods] The workers were evaluated for pulmonary function and peak expiratory flow (PEF), respiratory symptoms, smoking habits, and physical activity level. Descriptive statistical analysis and ANOVA one-way test were used. [Results] The mean age was 33.9 ± 8.25 years (18–59), pulmonary function: FVC: 95 ± 18% of predicted, FEV1: 95.0 ± 15.8% of predicted, FEV1/FVC ratio of 0.82 ± 0.09, and PEF = 499.7 ± 118.5 l/min. Overall, 85.1% of workers were classified that physically active, 7.93% of workers reported respiratory symptoms, and 14.28% reported being smokers. There was no statistically significant difference between groups for the variables of lung function. [Conclusion] The pulmonary function is preserved in foundry workers independently of exposure time. PMID:27064981

  15. Effective cross sections for production of single-strand breaks in plasmid DNA by 0.1 to 4.7 eV electrons.

    PubMed

    Panajotovic, Radmila; Martin, Frédéric; Cloutier, Pierre; Hunting, Darel; Sanche, Léon

    2006-04-01

    We determined effective cross sections for production of single-strand breaks (SSBs) in plasmid DNA [pGEM 3Zf(-)] by electrons of 10 eV and energies between 0.1 and 4.7 eV. After purification and lyophilization on a chemically clean tantalum foil, dry plasmid DNA samples were transferred into a high-vacuum chamber and bombarded by a monoenergetic electron beam. The amount of the circular relaxed DNA in the samples was separated from undamaged molecules and quantified using agarose gel electrophoresis. The effective cross sections were derived from the slope of the yield as a function of exposure and had values in the range of 10(-15)- 10(-14) cm2, giving an effective cross section of the order of 10(-18) cm2 per nucleotide. Their strong variation with incident electron energy and the resonant enhancement at 1 eV suggest that considerable damage is inflicted by very low-energy electrons to DNA, and it indicates the important role of pi* shape resonances in the bond-breaking process. Furthermore, the fact that the energy threshold for SSB production is practically zero implies that the sensitivity of DNA to electron impact is universal and is not limited to any particular energy range.

  16. Charge exchange and ionization cross sections of H{sup +}+H collision in dense quantum plasmas

    SciTech Connect

    Zhang, Ling-yu; Qi, Xin; Zhao, Xiao-ying; Meng, Dong-yuan; Xiao, Guo-qing; Duan, Wen-shan; Yang, Lei

    2013-11-15

    The plasma screening effects of dense quantum plasmas on H{sup +}+H charge exchange and ionization cross sections are calculated by the classical trajectory Monte Carlo method. For charge exchange cross sections, it is found that the screening effects reduce cross sections slightly in weak screening conditions. However, cross sections are reduced substantially in strong screening conditions. For ionization cross sections, with the increase of screening effects, cross sections for low energies increase more rapidly than those for high energies. When the screening effects are strong enough, it is found that ionization cross sections decrease with the increase of incident H{sup +} energy. In addition, the cross sections have been compared with those in weakly coupled plasmas. It is found that in weak screening conditions, plasma screening effects in the two plasmas are approximately the same, while in strong screening conditions, screening effects of dense quantum plasmas are stronger than those of weakly coupled plasmas.

  17. The 4He Total Photo-Absorption Cross Section With Two- Plus Three-Nucleon Interactions From Chiral Effective Field Theory

    SciTech Connect

    Quaglioni, S; Navratil, P

    2007-03-09

    The total photo-absorption cross section of {sup 4}He is evaluated microscopically using two- (NN) and three-nucleon (NNN) interactions based upon chiral effective field theory ({chi}EFT). The calculation is performed using the Lorentz integral transform method along with the ab initio no-core shell model approach. An important feature of the present study is the consistency of the NN and NNN interactions and also, through the Siegert theorem, of the two- and three-body current operators. This is due to the application of the {chi}EFT framework. The inclusion of the NNN interaction produces a suppression of the peak height and enhancement of the tail of the cross section. We compare to calculations obtained using other interactions and to representative experiments. The rather confused experimental situation in the giant resonance region prevents discrimination among different interaction models.

  18. Effect of Pesticide Exposure on Immunological, Hematological and Biochemical Parameters in Thai Orchid Farmers—A Cross-Sectional Study

    PubMed Central

    Aroonvilairat, Soraya; Kespichayawattana, Wannapa; Sornprachum, Thiwaree; Chaisuriya, Papada; Siwadune, Taweeratana; Ratanabanangkoon, Kavi

    2015-01-01

    Various studies have found that many Thai orchid farmers used excessive amounts of pesticides without proper protective gear, but no toxicological study has been made. This cross-sectional study aimed to evaluate the immunological, hematological and biochemical statuses of these farmers. Sixty four orchid farmers and 60 controls were studied. Plasma cholinesterase activity, the percentage and absolute number of B lymphocytes (CD19+) were significantly lower in the farmers group (3966.32 ± 1165.48 U/L, 11.61 ± 4.09% and 312.26 ± 164.83 cells/mm3, respectively) as compared to those of controls (5048.85 ± 1139.40 U/L, 14.32 ± 4.23%, 420.34 ± 195.18 cells/mm3, respectively). There was a statistically significant higher level of serum IgE among the orchid farmers (0.031 ± 0.011 mg/dL vs. 0.018 ± 0.007 mg/dL) but not IgG, IgA and IgM, levels. Serum lysozyme level, lymphocyte proliferative responses to mitogens, hematological parameters and kidney function test, were not significantly different between the two groups. The liver function profiles showed significantly lower levels of albumin and serum protein in the farmer group. Thus frequent pesticide exposure resulted in subtle changes of some biological parameters. These changes, though may not be clinically significant, strongly indicated that caution in handing pesticides by these farmers is warranted. PMID:26024358

  19. Effect of pesticide exposure on immunological, hematological and biochemical parameters in thai orchid farmers- a cross-sectional study.

    PubMed

    Aroonvilairat, Soraya; Kespichayawattana, Wannapa; Sornprachum, Thiwaree; Chaisuriya, Papada; Siwadune, Taweeratana; Ratanabanangkoon, Kavi

    2015-05-27

    Various studies have found that many Thai orchid farmers used excessive amounts of pesticides without proper protective gear, but no toxicological study has been made. This cross-sectional study aimed to evaluate the immunological, hematological and biochemical statuses of these farmers. Sixty four orchid farmers and 60 controls were studied. Plasma cholinesterase activity, the percentage and absolute number of B lymphocytes (CD19+) were significantly lower in the farmers group (3966.32±1165.48 U/L, 11.61±4.09% and 312.26±164.83 cells/mm3, respectively) as compared to those of controls (5048.85±1139.40 U/L, 14.32±4.23%, 420.34±195.18 cells/mm3, respectively). There was a statistically significant higher level of serum IgE among the orchid farmers (0.031±0.011 mg/dL vs. 0.018±0.007 mg/dL) but not IgG, IgA and IgM, levels. Serum lysozyme level, lymphocyte proliferative responses to mitogens, hematological parameters and kidney function test, were not significantly different between the two groups. The liver function profiles showed significantly lower levels of albumin and serum protein in the farmer group. Thus frequent pesticide exposure resulted in subtle changes of some biological parameters. These changes, though may not be clinically significant, strongly indicated that caution in handing pesticides by these farmers is warranted.

  20. Large cross sections for transitions with a small energy difference

    NASA Astrophysics Data System (ADS)

    McGuire, J. H.; Shakov, Kh. Kh.

    2009-05-01

    Cross sections for transitions between states with small differences in energy can be quite large. An example is the 1s-2p transition in atomic hydrogen caused by the impact of a fast charged particle [1] or a photon [3]. In such cases the actual cross section may become much larger than the simple geometric cross section. Such transitions are often difficult to observe in the laboratory. However, they can be evaluated numerically. This effect can be significant in analysis of astrophysical data, as pointed out by T. Nandi [2]. I discuss a few examples of calculations and give a physical explanation for this effect. [4pt] [1] J.H. McGuire, D. J. Land, J. G. Brennan and G. Basbas, Phys. Rev. A19, 2180 (1979).[0pt] [2] Kh.Kh. Shakov and J.H. McGuire, Phys. Rev. A67 033405 (2003). [0pt] [3] T. Nandi, private communication, 2008.

  1. Accurate universal parameterization of absorption cross sections II--neutron absorption cross sections

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Wilson, J. W.; Cucinotta, F. A.

    1997-01-01

    A recent parameterization (here after referred as paper I, Ref. [4]) of absorption cross sections for any system of charged ions collisions including proton -nucleus collisions, is extended for neutron-nucleus collisions valid from approximately 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pair (charged and/or uncharged). The parameters are associated with the physics of the problem. At lower energies, the optical potential at the surface is important and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  2. Accurate universal parameterization of absorption cross sections II — neutron absorption cross sections

    NASA Astrophysics Data System (ADS)

    Tripathi, R. K.; Wilson, John W.; Cucinotta, Francis A.

    1997-06-01

    A recent parameterization (here after referred as paper I, Ref. [4]) of absorption cross sections for any system of charged ions collisions including proton -nucleus collisions, is extended for neutron-nucleus collisions valid from ˜ 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pair (charged and/or uncharged). The parameters are associated with the physics of the problem. At lower energies, the optical potential at the surface is important and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  3. Ultrasonographic investigation of the effect of positive end-expiratory pressure on the cross-sectional area of the femoral vein.

    PubMed

    Ryu, J H; Han, S S; Choi, W J; Kim, H; Lee, S C; Do, S H; Son, Y K

    2013-02-01

    Femoral veins are commonly used as a relatively safe alternative route for central venous cannulation. Several maneuvers are used to increase the cross-sectional area of the vein. In this study, we assessed the effect of positive end-expiratory pressure (PEEP) on the cross-sectional area (CSA) of femoral veins, using ultrasound in adult patients under positive pressure ventilation. All patients received a standardized induction of general anesthesia and intravenous fluid administration. Using ultrasound, the cross-sectional areas of both femoral veins were measured in 57 adult patients in the supine position without PEEP (control) and in the supine position with PEEP of 10 cm H(2)O. Mean arterial pressure and heart rate were recorded before and after the application of PEEP at 10 cm H(2)O. The application of 10 cm H(2)O PEEP significantly increased the CSA of the right femoral vein by 47.6 % and the left femoral vein by 48.4 % (each P < 0.001). Mean arterial pressure decreased by 2.6 mmHg (95 % CI 1.3-3.9; P < 0.001), whereas no significant change in heart rate was observed (P = 0.861). The CSA of the femoral vein is augmented with the application of 10 cm H(2)O PEEP in adult patients undergoing positive pressure ventilation.

  4. Evaluation of plasma treatment effects on improving adhesive/dentin bonding by using the same tooth controls and varying cross-sectional surface areas

    PubMed Central

    Dong, Xiaoqing; Ritts, Andy Charles; Staller, Corey; Yu, Qingsong; Chen, Meng; Wang, Yong

    2013-01-01

    The objective of this study is to evaluate and verify the effectiveness of plasma treatment for improving adhesive/dentin interfacial bonding by performing micro-tensile bond strength (μTBS) test using the same-tooth controls and varying cross-sectional surface areas. Extracted unerupted human third molars were used by removing the crowns to expose the dentin surface. For each dentin surface, one half of it was treated with a non-thermal argon plasma brush, while another half was shielded with glass slide and used as untreated control. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were then applied as directed. The teeth thus prepared were further cut into micro-bar specimens with cross-sectional size of 1×1 mm2, 1×2 mm2 and 1×3 mm2 for μTBS test. The test results showed that plasma treated specimens gave substantially stronger adhesive/dentin bonding than their corresponding same tooth controls. As compared with their untreated controls, plasma treatment gave statistically significant higher bonding strength for specimens having cross-sectional area of 1×1 mm2 and 1×2 mm2, with mean increases of 30.8% and 45.1%, respectively. Interface examination using optical and electron microscopy verified that plasma treatment improved the quality of the adhesive/dentin interface by reducing defects/voids and increasing the resin tag length in dentin tubules. PMID:23841788

  5. Theoretical Formalism To Estimate the Positron Scattering Cross Section.

    PubMed

    Singh, Suvam; Dutta, Sangita; Naghma, Rahla; Antony, Bobby

    2016-07-21

    A theoretical formalism is introduced in this article to calculate the total cross sections for positron scattering. This method incorporates positron-target interaction in the spherical complex optical potential formalism. The study of positron collision has been quite subtle until now. However, recently, it has emerged as an interesting area due to its role in atomic and molecular structure physics, astrophysics, and medicine. With the present method, the total cross sections for simple atoms C, N, and O and their diatomic molecules C2, N2, and O2 are obtained and compared with existing data. The total cross section obtained in the present work gives a more consistent shape and magnitude than existing theories. The characteristic dip below 10 eV is identified due to the positronium formation. The deviation of the present cross section with measurements at energies below 10 eV is attributed to the neglect of forward angle-discrimination effects in experiments, the inefficiency of additivity rule for molecules, empirical treatment of positronium formation, and the neglect of annihilation reactions. In spite of these deficiencies, the present results show consistent behavior and reasonable agreement with previous data, wherever available. Besides, this is the first computational model to report positron scattering cross sections over the energy range from 1 to 5000 eV.

  6. Improved empirical parameterization for projectile fragmentation cross sections

    NASA Astrophysics Data System (ADS)

    Mei, B.

    2017-03-01

    A new empirical parametrization is developed for calculating the fragment cross sections in projectile fragmentation reactions at high energies (>100 MeV/nucleon). The new parametrization, FRACS, consists of two main parts, i.e., the mass yield and the isobaric distribution, on the basis of previous parametrizations. The formalism for the mass yield is improved to describe the target and the projectile energy dependences observed in measured fragmentation cross sections. The parametrization of the isobaric distribution is also modified to reproduce recent experimental data. Furthermore, an additional term is proposed and first implemented in the FRACS parametrization to account for the evident odd-even staggering effect observed in many experimental cross sections. Comparisons with extensive cross sections measured in various fragmentation reactions reveal that FRACS is in much better agreement with experimental data and can reproduce measured cross sections in most cases within a factor of 1.84, which is a much smaller rms deviation as compared to that of the recent parametrization EPAX3.

  7. Neutrino Cross Sections at Supernova Energies

    NASA Astrophysics Data System (ADS)

    Scholberg, Kate

    2017-01-01

    Neutrinos with energies between a few and a few tens of MeV are relevant for a number of physics topics. Notably, this is the energy range corresponding to emission of neutrinos from supernovae. In addition, it is relevant for studies of solar, reactor and atmospheric neutrinos, as well as for physics using accelerator-produced neutrinos from pions or radioactive nuclei decaying at rest. Surprisingly, with the exception of interactions on electrons and protons, the interactions of neutrinos with matter in this energy range are quite poorly understood, both theoretically and experimentally. This talk will describe neutrino physics and astrophysics in the supernova-neutrino energy range, the state of knowledge of cross sections on relevant nuclei, and initiatives for experimental measurements.

  8. Lunar Radar Cross Section at Low Frequency

    NASA Technical Reports Server (NTRS)

    Rodriguez, P.; Kennedy, E. J.; Kossey, P.; McCarrick, M.; Kaiser, M. L.; Bougeret, J.-L.; Tokarev, Y. V.

    2002-01-01

    Recent bistatic measurements of the lunar radar cross-section have extended the spectrum to long radio wavelength. We have utilized the HF Active Auroral Research Program (HAARP) radar facility near Gakona, Alaska to transmit high power pulses at 8.075 MHz to the Moon; the echo pulses were received onboard the NASA/WIND spacecraft by the WAVES HF receiver. This lunar radar experiment follows our previous use of earth-based HF radar with satellites to conduct space experiments. The spacecraft was approaching the Moon for a scheduled orbit perturbation when our experiment of 13 September 2001 was conducted. During the two-hour experiment, the radial distance of the satellite from the Moon varied from 28 to 24 Rm, where Rm is in lunar radii.

  9. Absolute photoneutron cross sections of Sm isotopes

    SciTech Connect

    Gheorghe, I.; Glodariu, T.; Utsunomiya, H.; Filipescu, D.; Nyhus, H.-T.; Renstrom, T.; Tesileanu, O.; Shima, T.; Takahisa, K.; Miyamoto, S.

    2015-02-24

    Photoneutron cross sections for seven samarium isotopes, {sup 144}Sm, {sup 147}Sm, {sup 148}Sm, {sup 149}Sm, {sup 150}Sm, {sup 152}Sm and {sup 154}Sm, have been investigated near neutron emission threshold using quasimonochromatic laser-Compton scattering γ-rays produced at the synchrotron radiation facility NewSUBARU. The results are important for nuclear astrophysics calculations and also for probing γ-ray strength functions in the vicinity of neutron threshold. Here we describe the neutron detection system and we discuss the related data analysis and the necessary method improvements for adapting the current experimental method to the working parameters of the future Gamma Beam System of Extreme Light Infrastructure - Nuclear Physics facility.

  10. Angle-averaged Compton cross sections

    SciTech Connect

    Nickel, G.H.

    1983-01-01

    The scattering of a photon by an individual free electron is characterized by six quantities: ..cap alpha.. = initial photon energy in units of m/sub 0/c/sup 2/; ..cap alpha../sub s/ = scattered photon energy in units of m/sub 0/c/sup 2/; ..beta.. = initial electron velocity in units of c; phi = angle between photon direction and electron direction in the laboratory frame (LF); theta = polar angle change due to Compton scattering, measured in the electron rest frame (ERF); and tau = azimuthal angle change in the ERF. We present an analytic expression for the average of the Compton cross section over phi, theta, and tau. The lowest order approximation to this equation is reasonably accurate for photons and electrons with energies of many keV.

  11. Top cross section measurement at CDF

    SciTech Connect

    Compostella, Gabriele; /INFN, CNAF /Padua U.

    2010-01-01

    This paper describes the latest measurements of the t{bar t} pair production cross section performed by the CDF Collaboration analyzing p{bar p} collisions at a center-of-mass energy of 1.96 TeV from Fermilab Tevatron, as presented at the XVIII International Workshop on Deep-Inelastic Scattering and Related Subjects. In order to test Standard Model predictions, several analysis methods are explored and all the top decay channels are considered, to better constrain the properties of the top quark and to search for possible sources of new physics affecting the pair production mechanism. Experimental results using an integrated luminosity up to 5.1 fb{sup -1} are presented.

  12. Charge Influence on Mini Black Hole's Cross Section

    NASA Astrophysics Data System (ADS)

    Caraça, R. S.; Malheiro, M.

    In this work we study the electric charge effect on the cross section production of charged mini black holes (MBH) in accelerators. We analyze the charged MBH solution using the fat brane approximation in the context of the ADD model. The maximum charge-mass ratio condition for the existence of a horizon radius is discussed. We show that the electric charge causes a decrease in this radius and, consequently, in the cross section. This reduction is negligible for protons and light-ions but can be important for heavy-ions.

  13. Iterative cross section sequence graph for handwritten character segmentation.

    PubMed

    Dawoud, Amer

    2007-08-01

    The iterative cross section sequence graph (ICSSG) is an algorithm for handwritten character segmentation. It expands the cross section sequence graph concept by applying it iteratively at equally spaced thresholds. The iterative thresholding reduces the effect of information loss associated with image binarization. ICSSG preserves the characters' skeletal structure by preventing the interference of pixels that causes flooding of adjacent characters' segments. Improving the structural quality of the characters' skeleton facilitates better feature extraction and classification, which improves the overall performance of optical character recognition (OCR). Experimental results showed significant improvements in OCR recognition rates compared to other well-established segmentation algorithms.

  14. Validity of approximate methods in molecular scattering. III - Effective potential and coupled states approximations for differential and gas kinetic cross sections

    NASA Technical Reports Server (NTRS)

    Monchick, L.; Green, S.

    1977-01-01

    Two dimensionality-reducing approximations, the j sub z-conserving coupled states (sometimes called the centrifugal decoupling) method and the effective potential method, were applied to collision calculations of He with CO and with HCl. The coupled states method was found to be sensitive to the interpretation of the centrifugal angular momentum quantum number in the body-fixed frame, but the choice leading to the original McGuire-Kouri expression for the scattering amplitude - and to the simplest formulas - proved to be quite successful in reproducing differential and gas kinetic cross sections. The computationally cheaper effective potential method was much less accurate.

  15. Evidence for a pairing anti-halo effect in the odd-even staggering in reaction cross sections of weakly bound nuclei

    SciTech Connect

    Hagino, K.; Sagawa, H.

    2011-07-15

    We investigate the spatial extension of weakly bound Ne and C isotopes by taking into account the pairing correlation with the Hartree-Fock-Bogoliubov (HFB) method and a three-body model, respectively. We show that the odd-even staggering in the reaction cross sections of {sup 30,31,32}Ne and {sup 14,15,16}C are successfully reproduced, and thus the staggering can be attributed to the pairing anti-halo effect. A correlation between a one-neutron separation energy and the anti-halo effect is demonstrated for s and p waves using the HFB wave functions.

  16. Partial wave analysis of scattering with the nonlocal Aharonov-Bohm effect and the anomalous cross section induced by quantum interference

    SciTech Connect

    Lin, D.-H.

    2004-05-01

    Partial wave theory of a three dimensional scattering problem for an arbitrary short range potential and a nonlocal Aharonov-Bohm magnetic flux is established. The scattering process of a 'hard sphere'-like potential and the magnetic flux is examined. An anomalous total cross section is revealed at the specific quantized magnetic flux at low energy which helps explain the composite fermion and boson model in the fractional quantum Hall effect. Since the nonlocal quantum interference of magnetic flux on the charged particles is universal, the nonlocal effect is expected to appear in a quite general potential system and will be useful in understanding some other phenomena in mesoscopic physics.

  17. Cross-Sectional Transport Imaging in a Multijunction Solar Cell

    SciTech Connect

    Haegel, Nancy M.; Ke, Chi-Wen; Taha, Hesham; Guthrey, Harvey; Fetzer, C. M.; King, Richard

    2015-06-14

    Combining highly localized electron-beam excitation at a point with the spatial resolution capability of optical near-field imaging, we have imaged carrier transport in a cross-sectioned multijunction (GaInP/GaInAs/Ge) solar cell. We image energy transport associated with carrier diffusion throughout the full width of the middle (GaInAs) cell and luminescent coupling from point excitation in the top cell GaInP to the middle cell. Supporting cathodoluminescence and near-field photoluminescence measurements demonstrate excitation-dependent Fermi level splitting effects that influence cross-sectioned spectroscopy results as well as transport limitations on the spatial resolution of cross-sectional measurements.

  18. Phenomenological barrier parameters for total reaction cross section

    NASA Astrophysics Data System (ADS)

    Phookan, C. K.; Kalita, K.

    2016-01-01

    A phenomenological formula for total reaction cross section is introduced for reactions induced by three types of projectiles. The formula is based on Wong's formula in which, the barrier parameters are calculated from the Bass, Aage Winther and the Akyuz Winther potentials. For the reactions studied, we find that a uniform correction of the barrier parameters can account for the total reaction cross section satisfactorily. An unusually large deviation of the barrier parameters is noticed for the reaction {}8{B} + {}^{58}{Ni}. Arguments are given that most likely the radius of the proton halo nucleus {}8{B} is not well accounted by the above potentials and hence, an increase in the effective radius of {}^8{B} is proposed. Analysis is also presented for the reaction {}^{11}{Li} + {}^{208}{Pb} by making the assumption that its reduced total reaction cross section lies on the same trajectory as that for other halo reactions.

  19. Inclined Bodies of Various Cross Sections at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Jorgensen, Leland H.

    1958-01-01

    To aid in assessing effects of cross-sectional shape on body aerodynamics, the forces and moments have been measured for bodies with circular, elliptic, square, and triangular cross sections at Mach numbers 1.98 and 3.88. Results for bodies with noncircular cross sections have been compared with results for bodies of revolution having the same axial distribution of cross-sectional area (and, thus, the same equivalent fineness ratio). Comparisons have been made for bodies of fineness ratios 6 and 10 at angles of attack from 0 deg to about 20 deg and for Reynolds numbers, based on body length, of 4.0 x 10(exp 6) and 6.7 x 10(exp 6). The results of this investigation show that distinct aerodynamic advantages can be obtained by using bodies with noncircular cross sections. At certain angles of bank, bodies with elliptic, square, and triangular cross sections develop considerably greater lift and lift-drag ratios than equivalent bodies of revolution. For bodies with elliptic cross sections, lift and pitching-moment coefficients can be correlated with corresponding coefficients for equivalent circular bodies. It has been found that the ratios of lift and pitching-moment coefficients for an elliptic body to those for an equivalent circular body are practically constant with change in both angle of attack and Mach number. These lift and moment ratios are given very accurately by slender-body theory. As a result of this agreement, the method of NACA Rep. 1048 for computing forces and moments for bodies of revolution has been simply extended to bodies with elliptic cross sections. For the cases considered (elliptic bodies of fineness ratios 6 and 10 having cross-sectional axis ratios of 1.5 and 2), agreement of theory with experiment is very good. As a supplement to the force and moment results, visual studies of the flow over bodies have been made by use of the vapor-screen, sublimation, and white-lead techniques. Photographs from these studies are included in the report.

  20. The total neutron cross section of liquid para-hydrogen

    NASA Astrophysics Data System (ADS)

    Celli, M.; Rhodes, N.; Soper, A. K.; Zoppi, M.

    1999-12-01

    We have measured, using the pulsed neutron source ISIS, the total neutron cross section of liquid para-hydrogen in the vicinity of the triple point. The experimental results compare only qualitatively with the results of the Young and Koppel theory. However, a much better agreement is found once modifications are included in the model which effectively take into account the intermolecular interactions.

  1. Single-level resonance parameters fit nuclear cross-sections

    NASA Technical Reports Server (NTRS)

    Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

    1970-01-01

    Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

  2. Total and ionization cross sections of electron scattering by fluorocarbons

    NASA Astrophysics Data System (ADS)

    Antony, B. K.; Joshipura, K. N.; Mason, N. J.

    2005-02-01

    Electron impact total cross sections (50-2000 eV) and total ionization cross sections (threshold to 2000 eV) are calculated for typical plasma etching molecules CF4, C2F4, C2F6, C3F8 and CF3I and the CFx (x = 1-3) radicals. The total elastic and inelastic cross sections are determined in the spherical complex potential formalism. The sum of the two gives the total cross section and the total inelastic cross section is used to calculate the total ionization cross sections. The present total and ionization cross sections are found to be consistent with other theories and experimental measurements, where they exist. Our total cross section results for CFx (x = 1-3) radicals presented here are first estimates on these species.

  3. Experiments on Antiprotons: Antiproton-Nucleon Cross Sections

    DOE R&D Accomplishments Database

    Chamberlain, Owen; Keller, Donald V.; Mermond, Ronald; Segre, Emilio; Steiner, Herbert M.; Ypsilantis, Tom

    1957-07-22

    In this paper experiments are reported on annihilation and scattering of antiprotons in H{sub 2}O , D{sub 2}O, and O{sub 2}. From the data measured it is possible to obtain an antiproton-proton and an antiproton-deuteron cross section at 457 Mev (lab). Further analysis gives the p-p and p-n cross sections as 104 mb for the p-p reaction cross section and 113 mb for the p-n reaction cross section. The respective annihilation cross sections are 89 and 74 mb. The Glauber correction necessary in order to pass from the p-d to the p-n cross section by subtraction of the p-p cross section is unfortunately large and somewhat uncertain. The data are compared with the p-p and p-n cross sections and with other results on p-p collisions.

  4. Hydraulic visibility and effective cross sections based on hydrodynamical modeling of flow lines gained by satellite altimetry

    NASA Astrophysics Data System (ADS)

    Biancamaria, S.; Garambois, P. A.; Calmant, S.; Roux, H.; Paris, A.; Monnier, J.; Santos da Silva, J.

    2015-12-01

    Hydrodynamic laws predict that irregularities in a river bed geometry produce spatial and temporal variations in the water level, hence in its slope. Conversely, observation of these changes is a goal of the SWOT mission with the determination of the discharge as a final objective. In this study, we analyse the relationship between river bed undulations and water surface for an ungauged reach of the Xingu river, a first order tributary of the Amazon river. It is crosscut more than 10 times by a single ENVISAT track over a hundred of km. We have determined time series of water levelsat each of these crossings, called virtual stations (VS), hence slopes of the flow line. Using the discharge series computed by Paiva et al. (2013) between 1998 and 2009, Paris et al. (submitted) determined at each VS a rating curve relating these simulated discharge with the ENVISAT height series. One parameter of these rating curves is the zero-flow depth Z 0 . We show that it is possible to explain the spatial and temporal variations of the water surface slope in terms of hydrodynamical response of the longitudinal changes of the river bed geometry given by the successive values of Z 0 . Our experiment is based on an effective, single thread representation of a braided river, realistic values for the Manning coefficient and river widths picked up on JERS images. This study confirms that simulated flow lines are consistent with water surface elevations (WSE) and slopes gained by satellite altimetry. Hydrodynamical signatures are more visible where the river bed geometry varies significantly, and for reaches with a strong downstream control. Therefore, this study suggests that the longitudinal variations of the slope might be an interesting criteria for the question of river segmentation into elementary reaches for the SWOT mission which will provide continuous measurements of the water surface elevation, the slope and the reach width.

  5. Electron Elastic-Scattering Cross-Section Database

    National Institute of Standards and Technology Data Gateway

    SRD 64 NIST Electron Elastic-Scattering Cross-Section Database (PC database, no charge)   This database provides values of differential elastic-scattering cross sections, corresponding total elastic-scattering cross sections, phase shifts, and transport cross sections for elements with atomic numbers from 1 to 96 and for electron energies between 50 eV and 20,000 eV (in steps of 1 eV).

  6. Cross sections for electron collisions with dimethyl ether

    NASA Astrophysics Data System (ADS)

    Sugohara, R. T.; Homem, M. G. P.; Iga, I.; de Souza, G. L. C.; Machado, L. E.; Ferraz, J. R.; dos Santos, A. S.; Brescansin, L. M.; Lucchese, R. R.; Lee, M. T.

    2013-08-01

    We report a joint theoretical-experimental investigation of electron collision with dimethyl ether (DME) in the low- and intermediate-energy ranges. Experimental absolute differential, integral, and momentum-transfer cross sections for elastic e--DME scattering are reported in the 100-1000 eV energy range. Our measurements were performed using a crossed electron-beam-molecular-beam geometry. The angular distribution of the scattered electrons was converted to absolute cross section using the relative flow technique. Theoretically, elastic differential, integral, and momentum-transfer cross sections, as well as the grand-total and total absorption cross sections for electron collision with DME are calculated in the 1-1000 eV energy range. A single-center-expansion technique combined with the Padé approximant method is used in our calculations. A comparison between the present experimental and theoretical data shows very good agreement. Moreover, comparison with theoretical and experimental data for e--ethanol (an isomer of DME) scattering shows interesting isomeric effects.

  7. Cross section measurements via residual nuclear decays: Analysis methods

    SciTech Connect

    Zhou Fengqun; Gao Lei; Li Kuohu; Song Yueli; Zhang Fang; Kong Xiangzhong; Luo Junhua

    2009-11-15

    We develop an approach to calculating the pure cross section of the ground state of artificial radioactive nuclides that subtracts the effect of an excited state on the ground state. We apply a formalism to obtaining pure cross sections by subtracting the effect of excited states in the reactions {sup 122}Te(n,2n){sup 121}Te{sup g} and {sup 128}Te(n,2n){sup 127}Te{sup g}, induced by neutrons of about 14 MeV. The cross sections are measured by an activation relative to the {sup 93}Nb(n,2n){sup 92}Nb{sup m} reaction and are compared with results that take into account the effect of the excited state. Measurements are carried out by {gamma} detection using a coaxial high-purity germanium (HPGe) detector. As samples, spectroscopically pure Te powder is used. The fast neutrons are produced by the {sup 3}H(d,n){sup 4}He reaction. The neutron energies in these measurements are determined using the method of cross-section ratios between the {sup 90}Zr(n,2n){sup 89}Zr{sup m+g} and {sup 93}Nb(n,2n){sup 92}Nb{sup m} reactions.

  8. Mental Visualization of Objects from Cross-Sectional Images

    ERIC Educational Resources Information Center

    Wu, Bing; Klatzky, Roberta L.; Stetten, George D.

    2012-01-01

    We extended the classic anorthoscopic viewing procedure to test a model of visualization of 3D structures from 2D cross-sections. Four experiments were conducted to examine key processes described in the model, localizing cross-sections within a common frame of reference and spatiotemporal integration of cross sections into a hierarchical object…

  9. Cross-section and panel estimates of peer effects in early adolescent cannabis use: With a little help from my 'friends once removed'.

    PubMed

    Moriarty, John; McVicar, Duncan; Higgins, Kathryn

    2016-08-01

    Peer effects in adolescent cannabis are difficult to estimate, due in part to the lack of appropriate data on behaviour and social ties. This paper exploits survey data that have many desirable properties and have not previously been used for this purpose. The data set, collected from teenagers in three annual waves from 2002 to 2004 contains longitudinal information about friendship networks within schools (N = 5020). We exploit these data on network structure to estimate peer effects on adolescents from their nominated friends within school using two alternative approaches to identification. First, we present a cross-sectional instrumental variable (IV) estimate of peer effects that exploits network structure at the second degree, i.e. using information on friends of friends who are not themselves ego's friends to instrument for the cannabis use of friends. Second, we present an individual fixed effects estimate of peer effects using the full longitudinal structure of the data. Both innovations allow a greater degree of control for correlated effects than is commonly the case in the substance-use peer effects literature, improving our chances of obtaining estimates of peer effects than can be plausibly interpreted as causal. Both estimates suggest positive peer effects of non-trivial magnitude, although the IV estimate is imprecise. Furthermore, when we specify identical models with behaviour and characteristics of randomly selected school peers in place of friends', we find effectively zero effect from these 'placebo' peers, lending credence to our main estimates. We conclude that cross-sectional data can be used to estimate plausible positive peer effects on cannabis use where network structure information is available and appropriately exploited.

  10. Effects of long-term low-level radiation exposure after the Chernobyl catastrophe on immunoglobulins in children residing in contaminated areas: prospective and cross-sectional studies

    PubMed Central

    2014-01-01

    Background After the Chernobyl nuclear incident in 1986, children in the Narodichesky region, located 80 km west of the Chernobyl Power Plant, were exposed to 137Cesium (137Cs). Little is known about the effects of chronic low-level radiation on humoral immune responses in children residing in contaminated areas. Methods In four different approaches we investigated the effect of residential 137Cs exposure on immunoglobulins A, G, M, and specific immunoglobulin E in children. In a dynamic cohort (1993–1998) we included 617 children providing 2,407 repeated measurements; 421 and 523 children in two cross-sectional samples (1997–1998 and 2008–2010, respectively); and 25 participants in a small longitudinal cohort (1997–2010). All medical exams, blood collections, and analyses were conducted by the same team. We used mixed linear models to analyze repeated measurements in cohorts and general linear regression models for cross-sectional studies. Results Residential soil contamination in 2008 was highly correlated with the individual body burden of 137Cs. Serum IgG and IgM concentrations increased between 1993 and 1998. Children with higher 137Cs soil exposure had lower serum IgG levels, which, however, increased in the small cohort assessed between 1997 and 2010. Children within the fourth quintile of 137Cs soil exposure (266–310 kBq/m2) had higher IgM serum concentrations between 1993 and 1998 but these declined between 1997 and 2010. IgA remained stable with median 137Cs exposures related to higher IgA levels, which was corroborated in the cross-sectional study of 2008–2010. Specific IgE against indoor allergens was detected less often in children with higher 137Cs exposure. Conclusions Our findings show radiation-related alterations of immunoglobulins which by themselves do not constitute adverse health effects. Further investigations are necessary to understand how these changes affect health status. PMID:24886042

  11. High resolution imaging in cross-section of a metal-oxide-semiconductor field-effect-transistor using super-higher-order nonlinear dielectric microscopy

    NASA Astrophysics Data System (ADS)

    Chinone, N.; Yamasue, K.; Honda, K.; Cho, Y.

    2013-11-01

    Scanning nonlinear dielectric microscopy (SNDM) can evaluate carrier or charge distribution in semiconductor devices. High sensitivity to capacitance variation enables SNDM to measure the super-high-order (higher than 3rd) derivative of local capacitance-voltage (C-V) characteristics directly under the tip (dnC/dVn,n = 3, 4, ...). We demonstrate improvement of carrier density resolution by measurement of dnC/dVn,n = 1, 2, 3, 4 (super-higher-order method) in the cross-sectional observation of metal-oxide-semiconductor field-effect-transistor.

  12. Effect of kinetic boundary conditions on the cross section of the scattering of an electromagnetic wave by a small metal particle

    NASA Astrophysics Data System (ADS)

    Kuznetsova, I. A.; Lebedev, M. E.; Yushkanov, A. A.

    2015-09-01

    The scattering cross section of a small spherical metal particle in the presence of a plane electromagnetic wave is calculated in the dipole approximation. On the assumption that the radius of the particle is less than the skin-layer depth, the skin effect is disregarded. The calculations are performed with the aid of the kinetic approach at an arbitrary ratio of the free-path length of electrons to the radius of the particle. The model of the diffuse—specular Fuchs boundary conditions is used to obtain the nonequilibrium distribution function. Asymptotic expressions for large particles are in agreement with the known results of the macroscopic theory.

  13. Effect of the concentration of organic dyes on their surface plasmon enhanced two-photon absorption cross section using activated Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Cohanoschi, Ion; Yao, Sheng; Belfield, Kevin D.; Hernández, Florencio E.

    2007-04-01

    In this article we present the study of the surface plasmon enhanced two-photon absorption of a hydrophilic stilbene derivative (trans-4,4'-diaminostilbene) in aqueous solution at different concentrations. The observed exponential growth of the effective two-photon absorption cross section [σ2'(Au)] is attributed to the electric-field augmentation via surface plasmon resonance between nanoparticles, i.e., hot spots, and the molecular density on Au nanospheres. An unprecedented σ2'(Au)=550 000 GM has been measured. This result opens a new universe of applications in multiphoton imaging, photodynamic therapy, telecommunications, optical limiting, and multidimensional data storage using hybrid systems.

  14. SU-E-I-43: Photoelectric Cross Section Revisited

    SciTech Connect

    Haga, A; Nakagawa, K; Kotoku, J; Horikawa, Y

    2015-06-15

    Purpose: The importance of the precision in photoelectric cross-section value increases for recent developed technology such as dual energy computed tomography, in which some reconstruction algorithms require the energy dependence of the photo-absorption in each material composition of human being. In this study, we revisited the photoelectric cross-section calculation by self-consistent relativistic Hartree-Fock (HF) atomic model and compared with that widely distributed as “XCOM database” in National Institute of Standards and Technology, which was evaluated with localdensity approximation for electron-exchange (Fock)z potential. Methods: The photoelectric cross section can be calculated with the electron wave functions in initial atomic state (bound electron) and final continuum state (photoelectron). These electron states were constructed based on the selfconsistent HF calculation, where the repulsive Coulomb potential from the electron charge distribution (Hartree term) and the electron exchange potential with full electromagnetic interaction (Fock term) were included for the electron-electron interaction. The photoelectric cross sections were evaluated for He (Z=2), Be (Z=4), C (Z=6), O (Z=8), and Ne (Z=10) in energy range of 10keV to 1MeV. The Result was compared with XCOM database. Results: The difference of the photoelectric cross section between the present calculation and XCOM database was 8% at a maximum (in 10keV for Be). The agreement tends to be better as the atomic number increases. The contribution from each atomic shell has a considerable discrepancy with XCOM database except for K-shell. However, because the photoelectric cross section arising from K-shell is dominant, the net photoelectric cross section was almost insensitive to the different handling in Fock potential. Conclusion: The photoelectric cross-section program has been developed based on the fully self-consistent relativistic HF atomic model. Due to small effect on the Fock

  15. APPARATUS FOR MEASURING TOTAL NEUTRON CROSS SECTIONS

    DOEpatents

    Cranberg, L.

    1959-10-13

    An apparatus is described for measuring high-resolution total neutron cross sections at high counting rate in the range above 50-kev neutron energy. The pulsed-beam time-of-flight technique is used to identify the neutrons of interest which are produced in the target of an electrostatic accelerator. Energy modulation of the accelerator . makes it possible to make observations at 100 energy points simultaneously. 761O An apparatus is described for monitoring the proton resonance of a liquid which is particulariy useful in the continuous purity analysis of heavy water. A hollow shell with parallel sides defines a meander chamber positioned within a uniform magnetic fieid. The liquid passes through an inlet at the outer edge of the chamber and through a spiral channel to the central region of the chamber where an outlet tube extends into the chamber perpendicular to the magnetic field. The radiofrequency energy for the monitor is coupled to a coil positioned coaxially with the outlet tube at its entrance point within the chamber. The improvement lies in the compact mechanical arrangement of the monitor unit whereby the liquid under analysis is subjected to the same magnetic field in the storage and sensing areas, and the entire unit is shielded from external electrostatic influences.

  16. Normalization of experimental electron cross sections.

    NASA Astrophysics Data System (ADS)

    Avdonina, N.; Felfli, Z.; Msezane, A. Z.

    1997-10-01

    Absolute experimental electron-impact differential cross sections (DCSs) can be obtained through an extrapolation of the relative generalized oscillator strength (GOS) values at some given impact energy E to zero momentum transfer squared K^2, the optical oscillator strength (OOS) [1]. We propose to normalize the relative experimental DCS data to the corresponding OOS value by extrapolating the GOS to K^2 = 0 without involving the nonphysical region. This is possible only by simultaneously increasing E and decreasing K^2 so that K^2 = 0 corresponds to E = ∞. Thus is avoided a divergence of fracd(GOS)d(K^2) at K^2 = 0 [2]. Another advantage of our method is that, over a wide range of small K^2 values the contribution of higher order terms of the Born series to the GOS function is negligible, contrary to the constant E case in which even order K^2 terms are non-Born [2]. Thus first Born approximation can be used to normalize relative experimental DCSs to the OOS. This method is applicable to both the excitation and ionization of atomic and molecular targets by electron impact. The latter case generalizes the method of ref. [3]. ^*Supported by AFOSR, NSF and DoE Div. of Chemical Sciences, OBES. ^1 E. N. Lassettre et al., J. Chem. Phys \\underline50, (1829) ^2 W. M. Huo, J. Chem. Phys \\underline71, 1593 (1979) ^3 A. Saenz, W Weyrich and P. Froelich, J. Phys. B \\underline29, 97 (1996)

  17. Spectroscopy and Photoabsorption Cross Sections of FNO

    NASA Astrophysics Data System (ADS)

    Burley, J. D.; Miller, C. E.; Johnston, H. S.

    1993-04-01

    The spectroscopy and photoabsorption cross sections of nitrosyl fluoride are investigated in the spectral region 350-180 nm. Results for 350-250 nm are in good agreement with the initial measurements of Johnston and Bertin and later measurements from Solgadi and Flament and Huber et al. The spectrum is assigned to a series of vibrational progressions which arise from (0, 0, 0)″ and involve excitation of the ν' 1 mode. Excitations to ( n, 0, 0)' and ( n, 0, 1)' make up the bulk of the spectrum, with promotions to ( n, 1, 0)', ( n, 0, 2)', and ( n, 1, 2)' becoming dominant at higher energies. Analysis of the spectrum results in values of ν' 1 = 1096 cm -1, ν' 2 = 480cm -1 and ν' 3 = 349 cm -1 for the excited state FNO frequencies. The experimental basis for the assignment of ν' 1 and ν' 3 is distinctly stronger than that for ν' 2. Below 250 nm, a broad, featureless continuum absorption is observed, which rises in intensity from σ = 1.77 × 10 -20cm 2 at 245 nm to 5.24 × 10 -19cm 2 at 180 nm.

  18. Cross-sectional imaging in Crohn disease.

    PubMed

    Furukawa, Akira; Saotome, Takao; Yamasaki, Michio; Maeda, Kiyosumi; Nitta, Norihisa; Takahashi, Masashi; Tsujikawa, Tomoyuki; Fujiyama, Yoshihide; Murata, Kiyoshi; Sakamoto, Tsutomu

    2004-01-01

    The role of cross-sectional imaging in the diagnosis of Crohn disease has expanded with recent technologic advances in computed tomography (CT) and magnetic resonance (MR) imaging that allow rapid acquisition of high-resolution images of the intestines. To acquire images of diagnostic quality, administration of a fairly large amount of intraluminal contrast agent prior to examination and scanning with intravenous contrast material injection are necessary. Both CT and MR imaging are reported to have a sensitivity of over 95% for the detection of Crohn disease; however, they may not allow early diagnosis. Colonoscopy and conventional enteroclysis studies are indicated for patients with early-stage disease. At more advanced stages, CT and MR imaging can help identify and characterize pathologically altered bowel segments as well as extraluminal lesions (eg, fistulas, abscesses, fibrofatty proliferation, increased vascularity of the vasa recta, mesenteric lymphadenopathy). These modalities can also clearly depict inflammatory lesion activity and conditions that require elective gastrointestinal surgery, thereby aiding in treatment planning. In the clinical setting, CT is currently the imaging modality of choice at most institutions; however, it is expected that MR imaging will soon play a comparable role. CT or MR imaging should be included in a comprehensive evaluation of patients with Crohn disease, along with conventional imaging and clinical and laboratory tests.

  19. Abdominal sarcoidosis: cross-sectional imaging findings

    PubMed Central

    Gezer, Naciye Sinem; Başara, Işıl; Altay, Canan; Harman, Mustafa; Rocher, Laurence; Karabulut, Nevzat; Seçil, Mustafa

    2015-01-01

    Sarcoidosis is a multisystem inflammatory disease of unknown etiology. The lungs and the lymphoid system are the most commonly involved organs. Extrapulmonary involvement is reported in 30% of patients, and the abdomen is the most common extrapulmonary site with a frequency of 50%–70%. Although intra-abdominal sarcoidosis is usually asymptomatic, its presence may affect the prognosis and treatment options. The lesions are less characteristic and may mimick neoplastic or infectious diseases such as lymphoma, diffuse metastasis, and granulomatous inflammation. The liver and spleen are the most common abdominal sites of involvement. Sarcoidosis of the gastrointestinal system, pancreas, and kidneys are extremely rare. Adenopathy which is most commonly found in the porta hepatis, exudative ascites, and multiple granulomatous nodules studding the peritoneum are the reported manifestations of abdominal sarcoidosis. Since abdominal sarcoidosis is less common and long-standing, unrecognized disease can result in significant morbidity and mortality. Imaging contributes to diagnosis and management of intra-abdominal sarcoidosis. In this report we reviewed the cross-sectional imaging findings of hepatobiliary, gastrointestinal, and genitourinary sarcoidosis. PMID:25512071

  20. [Fast neutron cross section measurements]. Progress report

    SciTech Connect

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are ``clean`` and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its ``data production`` phase.

  1. Graphs of the cross sections in the recommended Monte Carlo cross-section library at the Los Alamos Scientific Laboratory

    SciTech Connect

    Soran, P.D.; Seamon, R.E.

    1980-05-01

    Graphs of all neutron cross sections and photon production cross sections on the Recommended Monte Carlo Cross Section (RMCCS) library have been plotted along with local neutron heating numbers. Values for anti ..nu.., the average number of neutrons per fission, are also given.

  2. Radar Cross Section (RCS) Simulation for Wind Turbines

    DTIC Science & Technology

    2013-06-01

    research, some basic scattering characteristics of wind turbines are discussed. Several computational methods of RCS prediction are examined, citing...a wind turbine and assess its effect on the performance of radar and communication systems. In this research, some basic scattering characteristics ... characteristics of wind turbines. The radar cross section (RCS) is a parameter that is used to estimate the effect of a wind turbine on a system’s

  3. Extinction and backscatter cross sections of biological materials

    NASA Astrophysics Data System (ADS)

    Thomas, M. E.; Hahn, D. V.; Carr, A. K.; Limsui, D.; Carter, C. C.; Boggs, N. T.; Jackman, J.

    2008-04-01

    Aerosol backscatter and extinction cross-sections are required to model and evaluate the performance of both active and passive detection systems. A method has been developed that begins with laboratory measurements of thin films and suspensions of biological material to obtain the complex index refraction of the biological material from the UV to the LWIR. Using that result with particle size distribution and shape information as inputs to T-matrix or discrete dipole approximation (DDA) calculations yields the extinction cross-section and backscatter cross section as a function of wavelength. These are important inputs to the lidar equation. In a continuing effort to provide validated optical cross-sections, measurements have been made on a number of high purity biological species in the laboratory as well as measurements of material released at recent field tests. The resulting observed differences between laboratory and field measurements aid in distinguishing between intrinsic and extrinsic effects, which can affect the characteristic signatures of important biological aerosols. A variety of biological and test aerosols are examined, including Bacillus atrophaeus (BG), and Erwina, ovalbumin, silica and polystyrene.

  4. Electron impact ionisation cross sections of iron hydrogen clusters

    NASA Astrophysics Data System (ADS)

    Huber, Stefan E.; Sukuba, Ivan; Urban, Jan; Limtrakul, Jumras; Probst, Michael

    2016-09-01

    We computed electron impact ionisation cross sections (EICSs) of iron hydrogen clusters, FeH n with n = 1,2, ...,10, from the ionisation threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. The maxima of the cross sections for the iron hydrogen clusters range from 6.13 × 10-16 cm2 at 60 eV to 8.76 × 10-16 cm2 at 76 eV for BEB-AE (BEB method based on quantum-chemical data from all-electron basis sets) calculations, from 4.15 × 10-16 cm2 at 77 eV to 7.61 × 10-16 cm2 at 80 eV for BEB-ECP (BEB method based on quantum-chemical data from effective-core potentials for inner-core electrons) calculations and from 2.49 × 10-16 cm2 at 43.5 eV to 7.04 × 10-16 cm2 at 51 eV for the DM method. Cross sections calculated via the BEB method are substantially higher than the ones obtained via the DM method, up to a factor of about two for FeH and FeH2. The formation of Fe-H bonds depopulates the iron 4 s orbital, causing significantly lower cross sections for the small iron hydrides compared to atomic iron. Both the DM and BEB cross sections can be fitted perfectly against a simple expression used in modelling and simulation codes in the framework of nuclear fusion research. The energetics of the iron hydrogen clusters change substantially when exact exchange is present in the density functional, while the cluster geometries do not depend on this choice.

  5. Differential cross sections for muonic atom scattering from hydrogenic molecules

    SciTech Connect

    Adamczak, Andrzej

    2006-10-15

    The differential cross sections for low-energy muonic hydrogen atom scattering from hydrogenic molecules are directly expressed by the corresponding amplitudes for muonic atom scattering from hydrogen-isotope nuclei. The energy and angular dependence of these three-body amplitudes is thus taken naturally into account in scattering from molecules, without involving any pseudopotentials. Effects of the internal motion of nuclei inside the target molecules are included for every initial rotational-vibrational state. These effects are very significant as the considered three-body amplitudes often vary strongly within the energy interval < or approx. 0.1 eV. The differential cross sections, calculated using the presented method, have been successfully used for planning and interpreting many experiments in low-energy muon physics. Studies of {mu}{sup -} nuclear capture in p{mu} and the measurement of the Lamb shift in p{mu} atoms created in H{sub 2} gaseous targets are recent examples.

  6. Differential collision cross-sections for atomic oxygen

    NASA Technical Reports Server (NTRS)

    Torr, Douglas G.

    1991-01-01

    Differential collision cross-sections of O on N2 and other gases were measured to understand vehicle-environmental contamination effects in orbit. The following subject areas are also covered: groundbased scientific observations of rocket releases during NICARE-1; data compression study for the UVI; science priorities for UV imaging in the mid-1990's; and assessment of optimizations possible in UV imaging systems.

  7. Disentangling effects of socioeconomic status on obesity: A cross-sectional study of the Spanish adult population.

    PubMed

    Merino Ventosa, María; Urbanos-Garrido, Rosa M Maria Merino Ven Gmail Com

    2016-09-01

    This paper complements previous estimations regarding socioeconomic inequalities in obesity for Spanish adults, and provides new evidence about the mechanisms through which socioeconomic status (SES) affects obesity. Microdata from the Spanish National Health Survey (SNHS) 2011-2012 are analysed. Corrected concentration indices (CCI) are calculated to measure inequality. Path analysis is employed to disentangle direct and indirect effects of SES on obesity, where dietary patterns, physical activity and sleep habits act as mediator variables. Multivariate logistic models are used to select those exogenous variables to be included in the path diagram. Men and women are analysed separately. Our results show significant pro-rich inequality in the distribution of obesity (the poorer the more obese), particularly for women (CCI=-0.070 for men, CCI=-0.079 for women). The indirect effects of SES on obesity (those transmitted via mediator variables) are quite modest (3.3% for males, 2.4% for females) due to three reasons. Firstly, dietary habits do not show a significant mediating effect. Secondly, the mediating effect of physical activity in leisure time, although significant (14% for males, 11.1% for females), is offset by that related to main activity. Finally, sleep habits contribution to total effect of SES on obesity is statistically significant but small (roughly 1%). Our results indicate that promoting physical activity in leisure time for those with a low SES, particularly for men, would contribute to prevent obesity and to reduce health inequalities. Promotion of adequate sleep habits for women with a low SES might have a similar effect. However, interventions aimed to reduce sedentarism related to main activity, although useful to prevent obesity, would amplify the obesity socioeconomic gradient. Since effects of SES are different for men and women, socioeconomic health inequalities should be addressed also from a gender perspective.

  8. Nucleon-nucleus interaction data base: Total nuclear and absorption cross sections

    NASA Astrophysics Data System (ADS)

    Wilson, J. W.; Townsend, L. W.; Buck, W. W.; Chun, S. Y.; Hong, B. S.; Lamkin, S. L.

    1988-08-01

    Neutron total cross sections are represented for Li to Pu targets at energies above 0.1 MeV and less than 100 MeV using a modified nuclear Ramsauer formalism. The formalism is derived for energies above 100 MeV by fitting theoretical cross sections. Neutron absorption cross sections are represented by analytic expressions of similar form, but shape resonance phenomena of the Ramsauer effect is not present. Elastic differential cross sections are given as a renormalized impulse approximation. These cross section data bases are useful for nucleon transport applications.

  9. Nucleon-nucleus interaction data base: Total nuclear and absorption cross sections

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Townsend, L. W.; Buck, W. W.; Chun, S. Y.; Hong, B. S.; Lamkin, S. L.

    1988-01-01

    Neutron total cross sections are represented for Li to Pu targets at energies above 0.1 MeV and less than 100 MeV using a modified nuclear Ramsauer formalism. The formalism is derived for energies above 100 MeV by fitting theoretical cross sections. Neutron absorption cross sections are represented by analytic expressions of similar form, but shape resonance phenomena of the Ramsauer effect is not present. Elastic differential cross sections are given as a renormalized impulse approximation. These cross section data bases are useful for nucleon transport applications.

  10. Total and partial photoneutron cross sections for Pb isotopes

    NASA Astrophysics Data System (ADS)

    Kondo, T.; Utsunomiya, H.; Goriely, S.; Daoutidis, I.; Iwamoto, C.; Akimune, H.; Okamoto, A.; Yamagata, T.; Kamata, M.; Itoh, O.; Toyokawa, H.; Lui, Y.-W.; Harada, H.; Kitatani, F.; Hilaire, S.; Koning, A. J.

    2012-07-01

    Using quasimonochromatic laser-Compton scattering γ rays, total photoneutron cross sections were measured for 206,207,208Pb near neutron threshold with a high-efficiency 4π neutron detector. Partial E1 and M1 photoneutron cross sections along with total cross sections were determined for 207,208Pb at four energies near threshold by measuring anisotropies in photoneutron emission with linearly polarized γ rays. The E1 strength dominates over the M1 strength in the neutron channel where E1 photoneutron cross sections show extra strength of the pygmy dipole resonance in 207,208Pb near the neutron threshold corresponding to 0.32%-0.42% of the Thomas-Reiche-Kuhn sum rule. Several μN2 units of B(M1)↑ strength were observed in 207,208Pb just above neutron threshold, which correspond to an M1 cross section less than 10% of the total photoneutron cross section.

  11. Color dipole cross section and inelastic structure function

    NASA Astrophysics Data System (ADS)

    Jeong, Yu Seon; Kim, C. S.; Luu, Minh Vu; Reno, Mary Hall

    2014-11-01

    Instead of starting from a theoretically motivated form of the color dipole cross section in the dipole picture of deep inelastic scattering, we start with a parametrization of the deep inelastic structure function for electromagnetic scattering with protons, and then extract the color dipole cross section. Using the parametrizations of F 2(ξ = x or W 2 , Q 2) by Donnachie-Landshoff and Block et al., we find the dipole cross section from an approximate form of the presumed dipole cross section convoluted with the perturbative photon wave function for virtual photon splitting into a color dipole with massless quarks. The color dipole cross section determined this way reproduces the original structure function within about 10% for 0 .1 GeV2 ≤ Q 2 ≤10 GeV2. We discuss the dipole cross section at large and small dipole sizes and compare our results with other parametrizations.

  12. Crosstalk in rectangular cross-section heterogeneous multicore fiber

    NASA Astrophysics Data System (ADS)

    Egorova, Olga N.; Astapovich, Maxim S.; Semjonov, Sergey L.

    2016-09-01

    Using neighboring cores with different mode propagation constants (indexes) is a well-known way to reduce crosstalk in multicore fiber (MCF). However, in actual field-deployed fiber, random bends can cause a reduction in the difference between the mode indexes of neighboring cores, which consequently increases crosstalk. The level of crosstalk induced by bending in both rectangular cross-section and circular cross-section heterogeneous MCF with cores arranged in a line was investigated. The experimental results obtained indicate that in contrast to circular cross-section MCF, no bending-induced crosstalk occurs in rectangular cross-section MCF wound on the mandrel without special control of cross-section orientation. Thus, to eliminate undesirable bending-induced crosstalk in heterogeneous MCF a rectangular cross-section should be employed.

  13. Partial Photoneutron Cross Sections for 207,208Pb

    NASA Astrophysics Data System (ADS)

    Kondo, T.; Utsunomiya, H.; Goriely, S.; Iwamoto, C.; Akimune, H.; Yamagata, T.; Toyokawa, H.; Harada, H.; Kitatani, F.; Lui, Y.-W.; Hilaire, S.; Koning, A. J.

    2014-05-01

    Using linearly-polarized laser-Compton scattering γ-rays, partial E1 and M1 photoneutron cross sections along with total cross sections were determined for 207,208Pb at four energies near neutron threshold by measuring anisotropies in photoneutron emission. Separately, total photoneutron cross sections were measured for 207,208Pb with a high-efficiency 4π neutron detector. The partial cross section measurement provides direct evidence for the presence of pygmy dipole resonance (PDR) in 207,208Pb in the vicinity of neutron threshold. The strength of PDR amounts to 0.32%-0.42% of the Thomas-Reiche-Kuhn sum rule. Several μN2 units of B(M1)↑ strength were observed in 207,208Pb just above neutron threshold, which correspond to M1 cross sections less than 10% of the total photoneutron cross sections.

  14. Electron-phonon interaction effect on the energy levels and diamagnetic susceptibility of quantum wires: Parallelogram and triangle cross section

    SciTech Connect

    Khordad, R. Bahramiyan, H.

    2014-03-28

    In this paper, optical phonon modes are studied within the framework of dielectric continuum approach for parallelogram and triangular quantum wires, including the derivation of the electron-phonon interaction Hamiltonian and a discussion on the effects of this interaction on the electronic energy levels. The polaronic energy shift is calculated for both ground-state and excited-state electron energy levels by applying the perturbative approach. The effects of the electron-phonon interaction on the expectation value of r{sup 2} and diamagnetic susceptibility for both quantum wires are discussed.

  15. A Cross-Sectional Comparison of the Effects of Phonotactic Probability and Neighborhood Density on Word Learning by Preschool Children

    ERIC Educational Resources Information Center

    Hoover, Jill R.; Storkel, Holly L.; Hogan, Tiffany P.

    2010-01-01

    Two experiments examined the effects of phonotactic probability and neighborhood density on word learning by 3-, 4-, and 5-year-old children. Nonwords orthogonally varying in probability and density were taught with learning and retention measured via picture naming. Experiment 1 used a within story probability/across story density exposure…

  16. A cross sectional study of the independent effect of occupation on lung function in British coal miners.

    PubMed Central

    Lewis, S; Bennett, J; Richards, K; Britton, J

    1996-01-01

    BACKGROUND: Chronic bronchitis and emphysema are now recognised complications of occupational exposure to coal dust, and since 1992 compensation has been available for miners with impaired lung function provided that they also have x ray film evidence of pneumoconiosis. However, many miners with heavy exposure to coal dust and impairment of lung function therefore do not qualify for compensation because they do not have simple pneumoconiosis. In the present study attempts were made to determine whether coal mining is an independent risk factor for impairment of lung function in a group of Nottinghamshire miners with no evidence of simple pneumoconiosis, by comparing these men with a group of local controls who were not occupationally exposed. METHOD: Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were obtained on 1286 miners with no evidence of pneumoconiosis on x ray film. Lung function data were also obtained from a random sample of 567 men aged between 40 and 70 living in a district of Nottingham and who had never worked in the mining industry or in any other dusty occupation. Multiple linear regression in SPSS was used to estimate the mean independent effect of mining on FEV1 and FVC after adjustment for age, height, and smoking, in all miners and controls, and in a subgroup of men of 45 and under. In men of 45 and under, the independent effects of mining and smoking on the probability of a deficit of one litre or more from modelled predicted FEV1 values were computed with logistic regression in EGRET. RESULTS: There was a significant mean effect of mining on FEV1 after adjustment for age, height, and smoking of -155 ml (95% confidence interval (95% CI) -74 to -236 ml, P < 0.001), but the size of effect was inversely related to age such that in men of 45 and under the estimated mean effect of mining was -251 ml (95% CI -140 to -361 ml, P < 0.001). In this subgroup of younger men, 4.7% of miners and 0.7% of controls had a deficit

  17. Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Adamczyk, Anne; Dick, Frank

    2008-01-01

    Differential cross sections for electromagnetic dissociation in nuclear collisions are calculated for the first time. In order to be useful for three - dimensional transport codes, these cross sections have been calculated in both the projectile and lab frames. The formulas for these cross sections are such that they can be immediately used in space radiation transport codes. Only a limited amount of data exists, but the comparison between theory and experiment is good.

  18. Measured microwave scattering cross sections of three meteorite specimens

    NASA Technical Reports Server (NTRS)

    Hughes, W. E.

    1972-01-01

    Three meteorite specimens were used in a microwave scattering experiment to determine the scattering cross sections of stony meteorites and iron meteorites in the frequency range from 10 to 14 GHz. The results indicate that the stony meteorites have a microwave scattering cross section that is 30 to 50 percent of their projected optical cross section. Measurements of the iron meteorite scattering were inconclusive because of specimen surface irregularities.

  19. Left atrial vascularised thrombus diagnosed by transoesophageal cross sectional echocardiography.

    PubMed Central

    Taams, M A; Gussenhoven, E J; Lancée, C T

    1987-01-01

    This report describes a patient with a Björk-Shiley mitral valve prosthesis in whom transoesophageal cross sectional echocardiography revealed a large vascularised mass within the left atrial appendage with smoke-like opacification of blood flow in the left atrium. Transoesophageal cross sectional echocardiography gave a detailed image of the lesion which was unobtainable with precordial cross sectional echocardiography. Images Fig 1 Fig 2 PMID:3426904

  20. Analytical formulation of the quantum electromagnetic cross section

    NASA Astrophysics Data System (ADS)

    Brandsema, Matthew J.; Narayanan, Ram M.; Lanzagorta, Marco

    2016-05-01

    It has been found that the quantum radar cross section (QRCS) equation can be written in terms of the Fourier transform of the surface atom distribution of the object. This paper uses this form to provide an analytical formulation of the quantum radar cross section by deriving closed form expressions for various geometries. These expressions are compared to the classical radar cross section (RCS) expressions and the quantum advantages are discerned from the differences in the equations. Multiphoton illumination is also briefly discussed.

  1. Giant dipole resonance parameters with uncertainties from photonuclear cross sections

    NASA Astrophysics Data System (ADS)

    Plujko, V. A.; Capote, R.; Gorbachenko, O. M.

    2011-09-01

    Updated values and corresponding uncertainties of isovector giant dipole resonance (IVGDR or GDR) model parameters are presented that are obtained by the least-squares fitting of theoretical photoabsorption cross sections to experimental data. The theoretical photoabsorption cross section is taken as a sum of the components corresponding to excitation of the GDR and quasideuteron contribution to the experimental photoabsorption cross section. The present compilation covers experimental data as of January 2010.

  2. High E{sub T} jet cross sections at CDF

    SciTech Connect

    Flaugher, B.; CDF Collaboration

    1996-08-01

    The inclusive jet cross section for {ital p}{ital {anti p}} collisions at {radical}s = 1.8 TeV as measured by the CDF collaboration will be presented. Preliminary CDF measurements of the {Sigma} E{sub T} cross section at {radical}s = 1.8 TeV and the central inclusive jet cross section at {radical}s = 0.630 TeV will also be shown.

  3. Cross section dependence of event rates at neutrino telescopes.

    PubMed

    Hussain, S; Marfatia, D; McKay, D W; Seckel, D

    2006-10-20

    We examine the dependence of event rates at neutrino telescopes on the neutrino-nucleon cross section for neutrinos with energy above 1 PeV, and contrast the results with those for cosmic ray experiments. Scaling of the standard model cross sections leaves the rate of upward events essentially unchanged. Details, such as detector depth and cross section inelasticity, can influence rates. Numerical estimates of upward shower, muon, and tau event rates in the IceCube detector confirm these results.

  4. Empirical parametrization of the two-photon-exchange effect contributions to the electron-proton elastic scattering cross section

    SciTech Connect

    Qattan, I. A.; Alsaad, A.

    2011-05-15

    The most recent electron-proton elastic scattering data were re-analyzed using an empirical parametrization of the two-photon-exchange (TPE) effect contributions to {sigma}{sub R}. The TPE effect contribution F(Q{sup 2},{epsilon}) was double Taylor series expanded as a polynomial of order n keeping only terms linear in {epsilon} to account for the experimentally observed and verified linearity of the Rosenbluth plots. We fix the ratio R=G{sub Ep}/G{sub Mp} to be that obtained from a fit to the recoil-polarization data and parametrize {sigma}{sub R} first by a three-parameter formula (fit I) and then by a two-parameter formula (fit III). In contrast to previous analyses, the fit parameter G{sub Mp}{sup 2} as obtained from these fits is either smaller or equal to the values obtained from our conventional Rosenbluth fit (fit II) but never larger. The ratio g(Q{sup 2})/G{sub Mp}{sup 2} which represents the ratio of the TPE and one-photon-exchange (OPE) effect contributions to the intercept of {sigma}{sub R} is large and it ranges 3%-88%. The ratio R{sub 1{gamma}x2{gamma}={tau}}f(Q{sup 2})/G{sub Ep}{sup 2} which represents the ratio of the TPE and OPE effect contributions to the slope of {sigma}{sub R} is also large, reaching a value of 12.0-14.4 at Q{sup 2}= 5.25 (GeV/c){sup 2}. The ratio R{sub 1{gamma}x2{gamma}} as obtained from fits I and III is consistent, within error, with those obtained from previous analyses. Our formulas seem to explain the linearity of {sigma}{sub R}. Moreover, our analysis shows that the extracted G{sub Ep}{sup 2} and G{sub Mp}{sup 2} using the conventional Rosenbluth separation method can in fact be broken into the usual OPE and TPE contributions. Therefore, {sigma}{sub R} can in fact be derived under weaker conditions than those imposed by the Born approximation. Our results show that the TPE amplitudes, g(Q{sup 2})/G{sub Mp}{sup 2} and f(Q{sup 2})/G{sub Mp}{sup 2}, are sizable and grow with Q{sup 2} value up to Q{sup 2}{approx}6 (Ge

  5. Pollutant effects on genotoxic parameters and tumor-associated protein levels in adults: a cross sectional study

    PubMed Central

    De Coster, Sam; Koppen, Gudrun; Bracke, Marc; Schroijen, Carmen; Den Hond, Elly; Nelen, Vera; Van de Mieroop, Els; Bruckers, Liesbeth; Bilau, Maaike; Baeyens, Willy; Schoeters, Greet; van Larebeke, Nik

    2008-01-01

    Background This study intended to investigate whether residence in areas polluted by heavy industry, waste incineration, a high density of traffic and housing or intensive use of pesticides, could contribute to the high incidence of cancer observed in Flanders. Methods Subjects were 1583 residents aged 50–65 from 9 areas with different types of pollution. Cadmium, lead, p,p'-DDE, hexachlorobenzene, PCBs and dioxin-like activity (Calux test) were measured in blood, and cadmium, t,t'-muconic acid and 1-hydroxypyrene in urine. Effect biomarkers were prostate specific antigen, carcinoembryonic antigen and p53 protein serum levels, number of micronuclei per 1000 binucleated peripheral blood cells, DNA damage (comet assay) in peripheral blood cells and 8-hydroxy-deoxyguanosine in urine. Confounding factors were taken into account. Results Overall significant differences between areas were found for carcinoembryonic antigen, micronuclei, 8-hydroxy-deoxyguanosine and DNA damage. Compared to a rural area with mainly fruit production, effect biomarkers were often significantly elevated around waste incinerators, in the cities of Antwerp and Ghent, in industrial areas and also in other rural areas. Within an industrial area DNA strand break levels were almost three times higher close to industrial installations than 5 kilometres upwind of the main industrial installations (p < 0.0001). Positive exposure-effect relationships were found for carcinoembryonic antigen (urinary cadmium, t,t'-muconic acid, 1-hydroxypyrene and blood lead), micronuclei (PCB118), DNA damage (PCB118) and 8-hydroxy-deoxyguanosine (t,t'-muconic acid, 1-hydroxypyrene). Also, we found significant associations between values of PSA above the p90 and higher values of urinary cadmium, between values of p53 above the p90 and higher serum levels of p,p'-DDE, hexachlorobenzene and marker PCBs (PCB 138, 153 and 180) and between serum levels of p,p'-DDE above the p90 and higher serum values of carcinoembryonic

  6. The effective atomic number revisited in the light of modern photon-interaction cross-section databases.

    PubMed

    Manohara, S R; Hanagodimath, S M; Thind, K S; Gerward, L

    2010-01-01

    The effective atomic number, Z(eff), has been calculated for fatty acids and cysteine. It is shown that Z(eff) is a useful parameter for low-Z materials at any energy above 1 keV. Absorption edges of medium-Z elements may complicate the energy dependence of Z(eff) below 10 keV. The notion of Z(eff) is perhaps most useful at energies where Compton scattering is dominating, and where Z(eff) is equal to the mean atomic number, Z, over a wide energy range around 1 MeV.

  7. Inclusive Cross Section Production of J/ψ in LEP

    NASA Astrophysics Data System (ADS)

    Osati, T.; Abubakri, B.

    2017-02-01

    Cross section production is one of the observable quantities in the hadronic systems. Inclusive cross section production J/ψ may be calculated through the use of the fragmentation c → J/ψ. In this paper we calculate the inclusive cross section production J/ψ about the pole of Z 0 in the e + e ‑ annihilation, through the lowest order regim of perturbative of QCD ananlyticaly. The obtained results arrive an excellent agreement with the exprimental data to produce the inclusive cross section production c → J/ψ.

  8. Flow in tubes of non-circular cross-sections

    NASA Astrophysics Data System (ADS)

    Quadir, Raushan Ara

    Laminar, viscous, incompressible flow in tubes of noncircular cross sections is investigated. The specific aims of the investigation are (1) to look at the problems of both developing flow and fully developed flow, (2) to consider noncircular cross sections in a more systematic manner than has been done in the past, and (3) to develop a relatively simple finite element technique for producing accurate numerical solutions of flow in tubes of fairly arbitrary cross sections. Fully developed flow in tubes is governed by a Poisson type equation for the mainstream velocity. Both analytical and numerical solutions are considered. The cross sections studied include elliptic and rectangular cross sections of different aspect ratios, some triangular cross sections, and a series of crescent-shaped cross sections. The physical characteristics of the flow are examined in a systematic manner in order to determine how these characteristics are affected by certain geometrical features of the cross section. Solutions fall into three basic categories depending on the shape of the cross section. In the first category, which includes circular and elliptic cross sections, solutions are possible in closed form. In the second, including rectangular and some triangular cross sections, solutions are in the form of infinite series. In the third, including cross sections of more complicated or irregular shapes, only numerical solutions are possible. Results of calculations of velocity profiles, flow rate, pumping power, and friction factor are presented in a way which can be useful for engineering applications. In numerical studies of both developing and fully developed flow finite element techniques are used. Results are obtained for tubes of rectangular and elliptic cross sections of different aspect ratios, for tubes of crescent-shaped cross sections, and a tube whose cross section is an oval of Cassini. For fully developed flow, results are compared with the corresponding exact

  9. Thermal Neutron Capture Cross Section of {sup 22}Ne

    SciTech Connect

    Belgya, T.; Uberseder, E.; Petrich, D.; Kaeppeler, F.

    2009-01-28

    The radiative thermal neutron capture cross section of the astrophysically important {sup 22}Ne nucleus has been measured at the guided cold neutron beam of the Budapest Research Reactor. High-pressure gas-bottles filled with mixtures of enriched {sup 22}Ne and CH{sub 4} were used. The cross section was determined by means of the comparator method, and an improved decay-scheme obtained in this work. The new value for the thermal neutron cross section is 52.7{+-}0.7 mb, 18% larger than the accepted value. The influence of the new cross section on the astrophysical reaction rate is under investigation.

  10. Neutron-capture Cross Sections from Indirect Measurements

    SciTech Connect

    Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J

    2011-10-18

    Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  11. Tearing instability in a tokamak with a noncircular cross section

    NASA Astrophysics Data System (ADS)

    Arsenin, V. V.; Skovoroda, A. A.

    2016-12-01

    Using a straight-column model to describe tokamak plasma with a noncircular cross section, it is shown how to (i) find the boundary of tearing instability from the condition of existence of a magnetohydrodynamic plasma equilibrium different from that of a straight cylinder by solving a two-dimensional linear boundary-value problem with a second-order equation with respect to the flux coordinate and (ii) find the spatial structure of the tearing mode and the corresponding effective Δ' when there is only one resonance magnetic surface in the plasma for a given axial wavenumber by solving some kind of a boundary-value problem for the perturbation. The proposed approach is illustrated by numerical calculations for the case of an elliptical cross section as an example.

  12. Calculation of the cross section for top quark production

    SciTech Connect

    Berger, E.L.; Contopanagos, H.

    1996-06-21

    The authors summarize calculations of the cross section for top quark production at hadron colliders within the context of perturbative quantum chromodynamics, including resummation of the effects of initial-state soft gluon radiation to all orders in the strong coupling strength. In their approach they resume the universal leading-logarithm contributions, and they restrict the calculation to the region of phase space that is demonstrably perturbative. They compare the approach with other methods. They present predictions of the physical cross section as a function of the top quark mass in proton-antiproton reactions at center-of-mass energies of 1.8 and 2.0 TeV, and they discuss estimated uncertainties.

  13. Carbon Fragmentation Cross Sections for Hadrontherapy and Space Radiation Protection

    NASA Astrophysics Data System (ADS)

    De Napoli, M.; Agodi, C.; Cirrone, G. A. P.; Cuttone, G.; Nicolosi, D.; Pandola, L.; Raciti, G.; Romano, F.; Sardina, D.; Scuderi, V.; Tropea, S.; Bondì, M.; Cappuzzello, F.; Carbone, D.; Cavallaro, M.

    2014-05-01

    Fragmentation reactions represent a serious complication in hadrontherapy and space radiation protection. In order to predict their effects, both reliable Monte Carlo codes and experimental data are needed. The shortage of precise measurements, especially of double differential cross sections, has triggered many dedicated experiments at relativistic energies. Aiming to explore the Fermi energy regime, as well, where different reaction mechanisms are involved, we measured the 12C fragmentation at 62 AMeV on a 12C and a 197Au target. A high granularity Si-CsI hodoscope allowed to identify the charge and the mass of detected fragments and measure their energy and emission angle. In this work we report the double differential cross sections for the production of different fragments as a function of the emission angle. Experimental results are compared with the GEANT-4 Monte Carlo predictions performed using two reaction models, the Quantum Molecular Dynamic and the Binary Light Ion Cascade.

  14. Cross-Section Measurements with the Radioactive Isotope Accelerator (RIA)

    SciTech Connect

    Stoyer, M A; Moody, K J; Wild, J F; Patin, J B; Shaughnessy, D A; Stoyer, N J; Harris, L J

    2002-11-19

    RIA will produce beams of exotic nuclei of unprecedented luminosity. Preliminary studies of the feasibility of measuring cross-sections of interest to the science based stockpile stewardship (SBSS) program will be presented, and several experimental techniques will be discussed. Cross-section modeling attempts for the A = 95 mass region will be shown. In addition, several radioactive isotopes could be collected for target production or medical isotope purposes while the main in-beam experiments are running. The inclusion of a broad range mass analyzer (BRAMA) capability at RIA will enable more effective utilization of the facility, enabling the performance of multiple experiments at the same time. This option will be briefly discussed.

  15. Atherosclerotic effects of long-term old and new antiepileptic drugs monotherapy: a cross-sectional comparative study.

    PubMed

    El-Farahaty, Reham M; El-Mitwalli, Ashraf; Azzam, Hanan; Wasel, Yasser; Elrakhawy, Mohamed M; Hasaneen, Bothina Mohammed

    2015-03-01

    This work aimed to evaluate the metabolic and atherogenic effects of long-term antiepileptic drugs in a group of Egyptian epileptic patients. Sixty-nine epileptic patients on antiepileptic drug monotherapy for at least 2 years and 34 control subjects were recruited in this study. Patients were divided into 5 subgroups according to antiepileptic drugs used (valproate, carbamazepine, lamotrigine, topiramate, and levetiracetam). Fasting lipid profile (total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol), lipoprotein(a), homocysteine, free thyroxine, thyroid-stimulating hormone, and common carotid artery intima-media thickness were measured for all subjects. Significant higher mean values of low-density lipoprotein cholesterol, low-density lipoprotein / high-density lipoprotein ratio, lipoprotein(a), homocysteine, significantly lower mean value of high-density lipoprotein cholesterol, and significantly larger diameter of common carotid artery intima-media thickness were observed in each drug-treated group versus control group. Our study supports that long-term monotherapy treatment with valproate, carbamazepine, lamotrigine, and topiramate had altered markers of vascular risk that might enhance atherosclerosis, whereas levetiracetam exerted minimal effect.

  16. A comparison between theoretical and experimental state-to-state charge transfer cross sections for H(+) + H2 at 20 eV: Evidence for quantum effects

    NASA Astrophysics Data System (ADS)

    Baer, Michael; Niedner, Gereon; Toennies, J. Peter

    1988-06-01

    A 3-D quantum mechanical close coupling study for the system H(+) +H2 is communicated. The quantum calculations, caried out in the finite order swiden approximation, show a better fit to previous experiments than the classical trajectory surface hopping (TSH) calculations, and provide direct evidence for the usefulness of a quantum treatment in predicting charge transfer (CT) processes. The total differential cross sections (summed over all final vibrational states) for the CT processes were calculated, in good agreement with experimental results. It is shown that a quantum mechanical treatment of both the inelastic and the charge transfer nonadiabatic processes is feasible and provides a superior description of the experiments compared to the TSH treatment. This demonstrates the importance of quantum effects in ion-molecule charge transfer.

  17. [Evaluation of health effect among occupational population exposed to nano-titanium dioxide: a cross-sectional study].

    PubMed

    Xu, H D; Zhou, J W; Tang, S C; Kong, F L; Li, X W; Shen, Z L; Yan, L; Chen, Z J; Zhao, L; Jia, G; Zhang, J

    2016-11-06

    Objective: To characterize the health effects of nano-titanium dioxide exposure in an occupational cohort. Methods: Eighty-five male employees of a nano-titanium dioxide manufacturing enterprise in Shandong Province were evaluated in September 2014. Forty-four were exposed to nano-titanium dioxide (exposure group), and 41 were not exposed to nano-titanium dioxide (control group). We collected employees' basic information, smoking and drinking history, previous medical history, family history, and occupational history. Differences in blood pressure, hematological parameters, and blood biochemistry between the two groups were analyzed and compared. Multiple linear regression analysis was used to investigate the effect of nano-titanium dioxide exposure on blood pressure, hematological parameters, and blood biochemistry indices after controlling for age, smoking, drinking, and body mass index (BMI). Twenty-five employees from the exposure group and 25 employees from the control group were selected at random for measurement of genetic damage by cytokinesis-block micronucleus assay. Poisson regression analysis was used to investigate the effect of nano-titanium dioxide exposure on micronucleus frequency or micronucleus cell frequency after controlling for age, smoking, drinking, and BMI. Results: The median (P25-P75) surface area concentration of particles deposited in the tracheobronchial region, the surface area concentration of particles deposited in the alveolar region, and particle number concentration in the exposure group were 35.35(24.31-57.42) μ m(2)/cm(3), 173.09(116.27-270.72) μ m(2)/cm(3), and 40 244.00 (17 803.50-78 679.00) /cm(3), respectively. These values were significantly higher than those in the control group 33.90 (27.44-43.29) μm(2)/cm(3), 150.50(125.82-192.87)μm(2)/cm(3), and 18 721.00 (12 721.00-51 898.50)/cm(3), respectively. Z values were 15.47, 15.96, and 14.54, respectively (P<0.001 for all three values). Multiple linear regression analysis

  18. Effect of projectile coherence on multiple differential cross sections for 75 keV proton impact on H2

    NASA Astrophysics Data System (ADS)

    Sharma, S.; Egodapitiya, K.; Madison, D.; Schulz, M.; Hasan, A.; Laforge, A.; Moshammer, R.

    2011-10-01

    Recent results in ion-atom collision experiments suggest that discrepancies between theory and experiment are at least partly due to the representation of incoming projectile by a delocalized wave (coherent treatment). Recently we reported an experiment designed to investigate this. There, DDCS were measured for two different positions of the collimating slit. In one case the width of the proton wave packet was larger than the inter-nuclear separation of a H2 molecule (coherent case), while in the other it was much smaller than that (incoherent case). The two data sets were clearly different where in the coherent case a Young type interference structure was present and in the incoherent case it was not. Our next effort was to see the effects of projectile coherence on other processes such as single electron capture. Here we discuss the details of such an experiment and the observed results. Recent results in ion-atom collision experiments suggest that discrepancies between theory and experiment are at least partly due to the representation of incoming projectile by a delocalized wave (coherent treatment). Recently we reported an experiment designed to investigate this. There, DDCS were measured for two different positions of the collimating slit. In one case the width of the proton wave packet was larger than the inter-nuclear separation of a H2 molecule (coherent case), while in the other it was much smaller than that (incoherent case). The two data sets were clearly different where in the coherent case a Young type interference structure was present and in the incoherent case it was not. Our next effort was to see the effects of projectile coherence on other processes such as single electron capture. Here we discuss the details of such an experiment and the observed results. Funded by NSF.

  19. The Effect of Attending Steiner Schools during Childhood on Health in Adulthood: A Multicentre Cross-Sectional Study

    PubMed Central

    Fischer, H. Felix; Binting, Sylvia; Bockelbrink, Angelina; Heusser, Peter; Hueck, Christoph; Keil, Thomas; Roll, Stephanie; Witt, Claudia

    2013-01-01

    Background It is speculated that attending Steiner schools, whose pedagogical principles include an account for healthy psycho-physical development, may have long-term beneficial health effects. We examined whether the current health status differed between former attendees of German Steiner schools and adults from the general population. Furthermore, we examined factors that might explain those differences. Methods We included former Steiner school attendees from 4 schools in Berlin, Hanover, Nuremberg and Stuttgart and randomly selected population controls. Using a self-report questionnaire we assessed sociodemographics, current and childhood lifestyle and health status. Outcomes were self-reports on 16 diseases: atopic dermatitis, allergic rhinitis, bronchial asthma, chronic obstructive pulmonary disease (COPD), cardiac arrhythmia, cardiac insufficiency, angina pectoris, arteriosclerosis, hypertension, hypercholesterolemia, osteoarthritis, rheumatism, cancer, diabetes, depression and multiple sclerosis. Furthermore, participants rated the symptom burden resulting from back pain, cold symptoms, headache, insomnia, joint pain, gastrointestinal symptoms and imbalance. Unadjusted and adjusted odds ratios were calculated for each outcome. Results 1136 Steiner school attendees and 1746 controls were eligible for analysis. Both groups were comparable regarding sex, age and region, but differed in nationality and educational status. After adjusting for possible confounders, we found statistically significant effects of Steiner school attendance for osteoarthritis (OR 0.69 [0.49–0.97]) and allergic rhinitis (OR 0.77, [0.59–1.00]) as well as for symptom burden from back pain (OR 0.80, [0.64–1.00]), insomnia (OR 0.65, [0.50–0.84]), joint pain (OR 0.62, [0.48–0.82]), gastrointestinal symptoms (OR 0.76, [0.58–1.00]) and imbalance (OR 0.60, [0.38–0.93]). Conclusions The risk of most examined diseases did not differ between former Steiner school attendees and the

  20. Effects of congruence between preferred and perceived learning environments in nursing education in Taiwan: a cross-sectional study

    PubMed Central

    Yeh, Ting-Kuang; Huang, Hsiu-Mei; Chan, Wing P; Chang, Chun-Yen

    2016-01-01

    Objective To investigate the effects of congruence between preferred and perceived learning environments on learning outcomes of nursing students. Setting A nursing course at a university in central Taiwan. Participants 124 Taiwanese nursing students enrolled in a 13-week problem-based Fundamental Nursing curriculum. Design and methods Students' preferred learning environment, perceptions about the learning environment and learning outcomes (knowledge, self-efficacy and attitudes) were assessed. On the basis of test scores measuring their preferred and perceived learning environments, students were assigned to one of two groups: a ‘preferred environment aligned with perceived learning environment’ group and a ‘preferred environment discordant with perceived learning environment’ group. Learning outcomes were analysed by group. Outcome measures Most participants preferred learning in a classroom environment that combined problem-based and lecture-based instruction. However, a mismatch of problem-based instruction with students' perceptions occurred. Learning outcomes were significantly better when students' perceptions of their instructional activities were congruent with their preferred learning environment. Conclusions As problem-based learning becomes a focus of educational reform in nursing, teachers need to be aware of students' preferences and perceptions of the learning environment. Teachers may also need to improve the match between an individual student's perception and a teacher's intention in the learning environment, and between the student's preferred and actual perceptions of the learning environment. PMID:27207620

  1. Effect of Demographic Status and Lifestyle Habits on Glycaemic Levels in Apparently Healthy Subjects: A Cross-Sectional Study

    PubMed Central

    Walatara, Kasuni Nisansala Wijesena

    2016-01-01

    Aim. To identify the effects of sociodemographic status, family history, and lifestyle habits on fasting blood glucose (FBG) and fasting serum insulin (FSI) levels in apparently healthy subjects. Methods. Information was gathered using an interviewer-administered questionnaire from 227 apparently healthy nondiabetic subjects residing in a suburban area in Sri Lanka. Venous blood samples were collected after an overnight fast for FBG and FSI analysis. Correlations and differences were analyzed using SPSS (ver. 17) software. Results. The majority of the subjects were females, having secondary or tertiary education, monthly income ≥Rs. 25,000 (USD 175), and a positive family history of diabetes. Among the subjects, 10.1% were identified as prediabetics and the majority had familial diabetes with monthly income ≥Rs. 25,000 (USD 175). Subjects with high income had significantly higher mean FBG. In addition FBG had a significant correlation with age. Males and subjects with less than 6 hours/day sleeping duration at night had significantly higher FBG. Subjects with less vigorous physical activity and longer sitting duration had significantly higher FSI levels. Conclusions. Increasing age, higher income, positive familial history of diabetes, sedentary lifestyle, and short sleep at night have positive impact on glycaemic status in apparently healthy subjects. PMID:27995147

  2. Effects of Scaling and Root Planing on Gingival Status during Menstrual Cycle- A Cross-Sectional Analytical Study

    PubMed Central

    Rathore, Shivani; Dev, Yash Paul; Singh, Preetinder; Basavaraj, Patthi; Gera, Karan

    2015-01-01

    Introduction Variations in sex steroid hormones, noticeable through the menstrual cycle of women, may impact periodontal health. A relationship between female sex hormone levels and periodontal changes during puberty, pregnancy, and menopause has been reported. Little research on gingival status at different periods of menstrual cycle, but very less work has been done to observe the effect of scaling on gingival status during different periods of menstrual cycle. Materials and Methods Thirty female subjects, aged 18-25 years were selected for a three month study. In Stage 1, clinical parameters {Plaque Index (PI), Gingival Index (GI), Modified Sulcular Bleeding Index (mSBI) and Probing depth (PD)} were recorded at three different time intervals {OV (Ovulation), PM (Premenstruation), M (Menstruation)} of their menstrual cycle, without scaling and polishing. In Stage 2, all clinical parameters were recorded at their subsequent menstrual cycle after scaling and polishing. Results In interstage analysis, OV 1 > OV 2, PM 1 > PM 2 and M 1> M 2. In intrastage analysis, for PI, mean difference between all values was not statistically significant. For mSBI, PM 1 > OV 1 > M 1, also PM 2 > OV 2 > M 2. For GI, PM 1 > OV 1 > M 1, also PM 2 > OV 2 > M 2. For PD, mean difference was not statistically significant. Conclusion Ovarian hormones influence gingival status of females, with an increase observed primarily during PM and OV phases of menstrual cycle. Scaling leads to a subsequent decrease in gingival inflammation. PMID:26557613

  3. Effect of low income on health-related quality of life: a cross-sectional study in northeast China.

    PubMed

    Zhang, Ying; Ou, Fengrong; Gao, Shuang; Gao, Qian; Hu, Liwen; Liu, Yang

    2015-03-01

    Following the dramatic socioeconomic transition since the 1980s in China, some people became unemployed and experienced a significant drop in income. The aim of this study was to assess the effects of low income on health-related quality of life (HRQOL) among the population in northeast China. A total of 5100 individuals in northeast China were randomly sampled and investigated using the 36-item Short-Form Health Survey (SF-36) from November 2005 to October 2006. According to the monthly per capita income level, the population was divided into different groups for analysis. Multiple linear regressions showed that low income, older age, disease, and unemployment were the important factors that could lead to worse HRQOL. Covariance analysis showed that there were significant differences in HRQOL scores among the subgroups of the low-income population. When the income level increased, HRQOL scores improved. This study could provide valuable information for planning integrated economic and public health policies to improve the health of people living in poverty.

  4. Effect of Weekend Admissions on the Treatment Process and Outcomes of Internal Medicine Patients: A Nationwide Cross-Sectional Study.

    PubMed

    Huang, Chun-Che; Huang, Yu-Tung; Hsu, Nin-Chieh; Chen, Jin-Shing; Yu, Chong-Jen

    2016-02-01

    Many studies address the effect of weekend admission on patient outcomes. This population-based study aimed to evaluate the relationship between weekend admission and the treatment process and outcomes of general internal medicine patients in Taiwan.A total of 82,340 patients (16,657 weekend and 65,683 weekday admissions) aged ≥20 years and admitted to the internal medicine departments of 17 medical centers between 2007 and 2009 were identified from the Taiwan National Health Insurance Research Database. A generalized estimating equation (GEE) analysis was used to compare patients admitted on weekends and those admitted on weekdays.Patients who were admitted on weekends were more likely to undergo intubation (odds ratio [OR]: 1.27; 95% confidence interval [CI]: 1.16-1.39; P < 0.001) and/or mechanical ventilation (OR, 1.25; 95% CI, 1.15-1.35; P < 0.001), cardio-pulmonary resuscitation (OR: 1.45; 95% CI: 1.05-2.01; P = 0.026), and be transferred to the intensive care unit (ICU) (OR: 1.16; 95% CI: 1.03-1.30; P = 0.015) compared with those admitted on weekdays. Weekend-admitted patients also had higher odds of in-hospital mortality (OR: 1.19; 95% CI: 1.09-1.30; P < 0.001) and hospital treatment cost (OR: 1.04; 95% CI: 1.01-1.06; P = 0.008) than weekday-admitted patients.General internal medicine patients who were admitted on weekends experienced more intensive care procedures and higher ICU admission, in-hospital mortality, and treatment cost. Intensive care utilization may serve as early indicator of poorer outcomes and a potential entry point to offer preventive intervention before proceeding to intensive treatment.

  5. Assessment of effectiveness of geologic isolation systems. CIRMIS data system. Volume 4. Driller's logs, stratigraphic cross section and utility routines

    SciTech Connect

    Friedrichs, D.R.

    1980-01-01

    The Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program is developing and applying the methodology for assessing the far-field, long-term post-closure safety of deep geologic nuclear waste repositories. AEGIS is being performed by Pacific Northwest Laboratory (PNL) under contract with the Office of Nuclear Waste Isolation (ONWI) for the Department of Energy (DOE). One task within AEGIS is the development of methodology for analysis of the consequences (water pathway) from loss of repository containment as defined by various release scenarios. Analysis of the long-term, far-field consequences of release scenarios requires the application of numerical codes which simulate the hydrologic systems, model the transport of released radionuclides through the hydrologic systems to the biosphere, and, where applicable, assess the radiological dose to humans. The various input parameters required in the analysis are compiled in data systems. The data are organized and prepared by various input subroutines for use by the hydrologic and transport codes. The hydrologic models simulate the groundwater flow systems and provide water flow directions, rates, and velocities as inputs to the transport models. Outputs from the transport models are basically graphs of radionuclide concentration in the groundwater plotted against time. After dilution in the receiving surface-water body (e.g., lake, river, bay), these data are the input source terms for the dose models, if dose assessments are required. The dose models calculate radiation dose to individuals and populations. CIRMIS (Comprehensive Information Retrieval and Model Input Sequence) Data System is a storage and retrieval system for model input and output data, including graphical interpretation and display. This is the fourth of four volumes of the description of the CIRMIS Data System.

  6. Cross Sections for Inner-Shell Ionization by Electron Impact

    SciTech Connect

    Llovet, Xavier; Powell, Cedric J.; Salvat, Francesc; Jablonski, Aleksander

    2014-03-15

    An analysis is presented of measured and calculated cross sections for inner-shell ionization by electron impact. We describe the essentials of classical and semiclassical models and of quantum approximations for computing ionization cross sections. The emphasis is on the recent formulation of the distorted-wave Born approximation by Bote and Salvat [Phys. Rev. A 77, 042701 (2008)] that has been used to generate an extensive database of cross sections for the ionization of the K shell and the L and M subshells of all elements from hydrogen to einsteinium (Z = 1 to Z = 99) by electrons and positrons with kinetic energies up to 1 GeV. We describe a systematic method for evaluating cross sections for emission of x rays and Auger electrons based on atomic transition probabilities from the Evaluated Atomic Data Library of Perkins et al. [Lawrence Livermore National Laboratory, UCRL-ID-50400, 1991]. We made an extensive comparison of measured K-shell, L-subshell, and M-subshell ionization cross sections and of Lα x-ray production cross sections with the corresponding calculated cross sections. We identified elements for which there were at least three (for K shells) or two (for L and M subshells) mutually consistent sets of cross-section measurements and for which the cross sections varied with energy as expected by theory. The overall average root-mean-square deviation between the measured and calculated cross sections was 10.9% and the overall average deviation was −2.5%. This degree of agreement between measured and calculated ionization and x-ray production cross sections was considered to be very satisfactory given the difficulties of these measurements.

  7. Section Builder: A finite element tool for analysis and design of composite beam cross-sections

    NASA Astrophysics Data System (ADS)

    Chakravarty, Uttam Kumar

    SectionBuilder is an innovative finite element based tool, developed for analysis and design of composite beam cross-sections. The tool can handle the cross-sections with parametric shapes and arbitrary configurations. It can also handle arbitrary lay-ups for predefined beam cross-section geometries in a consistent manner. The material properties for each layer of the cross-section can be defined on the basis of the design requirements. This tool is capable of dealing with multi-cell composite cross-sections with arbitrary lay-ups. It has also the benefit of handling the variation of thickness of skin and D-spars for beams such as rotor blades. A typical cross-section is considered as a collection of interconnected walls. Walls with arbitrary lay-ups based on predefined geometries and material properties are generated first. The complex composite beam cross-sections are developed by connecting the walls using various types of connectors. These connectors are compatible with the walls, i.e., the thickness of the layers of the walls must match with those of the connectors at the place of connection. Cross-sections are often reinforced by core material for constructing realistic rotor blade cross-sections. The tool has the ability to integrate core materials into the cross-sections. A mapped mesh is considered for meshing parametric shapes, walls and various connectors, whereas a free mesh is considered for meshing the core materials. A new algorithm based on the Delaunay refinement algorithm is developed for creating the best possible free mesh for core materials. After meshing the cross-section, the tool determines the sectional properties using finite element analysis. This tool computes sectional properties including stiffness matrix, compliance matrix, mass matrix, and principal axes. A visualization environment is integrated with the tool for visualizing the stress and strain distributions over the cross-section.

  8. Three-nucleon force effects in cross section and spin observables of elastic deuteron-proton scattering at 90 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Amir-Ahmadi, H. R.; Castelijns, R.; Deltuva, A.; Eslami-Kalantari, M.; Garderen, E. D. Van; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Kiš, M.; Löhner, H.; Mahjour-Shafiei, M.; Mardanpour, H.; Messchendorp, J. G.; Mukherjee, B.; Savran, D.; Sekiguchi, K.; Shende, S. V.; Witała, H.; Wörtche, H. J.

    2007-04-01

    The cross section and several spin-dependent observables have been measured with high precision for the reaction H(d→,p→)d at 90 MeV/nucleon. Several calculations were performed based either purely on two-nucleon potentials or also including three-nucleon potentials (3NP). The cross sections are consistent with all calculations including 3NPs. However, no single calculation reproduces the analyzing powers and spin-transfer coefficients, although some spin observables are reproduced to various degrees by the different calculations. A good understanding of the spin structure of 3NP is still lacking.

  9. Total cross sections for positrons scattered elastically from helium based on new measurements of total ionization cross sections

    NASA Technical Reports Server (NTRS)

    Diana, L. M.; Chaplin, R. L.; Brooks, D. L.; Adams, J. T.; Reyna, L. K.

    1990-01-01

    An improved technique is presented for employing the 2.3m spectrometer to measure total ionization cross sections, Q sub ion, for positrons incident on He. The new ionization cross section agree with the values reported earlier. Estimates are also presented of total elastic scattering cross section, Q sub el, obtained by subtracting from total scattering cross sections, Q sub tot, reported in the literature, the Q sub ion and Q sub Ps (total positronium formation cross sections) and total excitation cross sections, Q sub ex, published by another researcher. The Q sub ion and Q sub el measured with the 3m high resolution time-of-flight spectrometer for 54.9eV positrons are in accord with the results from the 2.3m spectrometer. The ionization cross sections are in fair agreement with theory tending for the most part to be higher, especially at 76.3 and 88.5eV. The elastic cross section agree quite well with theory to the vicinity of 50eV, but at 60eV and above the experimental elastic cross sections climb to and remain at about 0.30 pi a sub o sq while the theoretical values steadily decrease.

  10. Effect of surface energy constant and surface asymmetry constant in the charged particle emission cross-section for the reactions $ (78,82,86) Kr +(12) C $ 78 , 82 , 86 K r + 12 C

    NASA Astrophysics Data System (ADS)

    Nazarzadeh, P.; Davoodabadi, S.

    2016-12-01

    The effects of the surface energy constant and the surface asymmetry constant in the charged particle emission cross section, have been examined by using the proximity potentials Prox77, BW91, AW95. The charged particle emission cross-section for the reactions ^{78,82,86} Kr +^{12} C have been calculated. Good consistency between the results of this work and the experimental data have been obtained using appropriate values of these constants.

  11. Cross Sections for Electron Collisions with Carbon Monoxide

    SciTech Connect

    Itikawa, Yukikazu

    2015-03-15

    Cross section data are collected and reviewed for electron collisions with carbon monoxide. Collision processes included are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational and electronic states, ionization, and dissociation. For each process, recommended values of the cross sections are presented, when possible. The literature has been surveyed through to the end of 2013.

  12. Analysis of cross sections using various nuclear potential

    SciTech Connect

    Aziz, Azni Abdul; Kassim, Hasan Abu; Yusof, Norhasliza; Muhammad Zamrun, F.

    2014-05-02

    The relevant astrophysical reaction rates which are derived from the reaction cross sections are necessary input to the reaction network. In this work, we analyse several theoretical models of the nuclear potential which give better prediction of the cross sections for some selected reactions.

  13. Learning of Cross-Sectional Anatomy Using Clay Models

    ERIC Educational Resources Information Center

    Oh, Chang-Seok; Kim, Ji-Young; Choe, Yeon Hyeon

    2009-01-01

    We incorporated clay modeling into gross anatomy and neuro-anatomy courses to help students understand cross-sectional anatomy. By making clay models, cutting them and comparing cut surfaces to CT and MR images, students learned how cross-sectional two-dimensional images were created from three-dimensional structure of human organs. Most students…

  14. Benchmark Calculations of Electron-Impact Differential Cross Sections

    SciTech Connect

    Bray, I.; Bostock, C. J.; Fursa, D. V.; Hines, C. W.; Kadyrov, A. S.; Stelbovics, A. T.

    2011-05-11

    The calculation of electron-atom excitation and ionization cross section is considered in both the non-relativistic and relativistic scattering theory. We consider electron collisions with H, He, Cs, and Hg. Differential cross sections for elastic scattering and ionization are presented.

  15. Cross sections for scattering of electrons on BF_3

    NASA Astrophysics Data System (ADS)

    Radmilovic-Radjenovic, M.; Varambhia, H. N.; Vranic, M.; Tennyson, J.; Petrovic, Z. Lj.

    2008-07-01

    We calculate cross sections for elastic scattering and electronic excitation of BF_3 molecules by low energy electrons. The R-Matrix code Quantemol-N has been used for calculations. The cross sections indicate the presence of a shape resonance of symmetry B_1 (A_2'' in D_3h) at around 4.5 eV.

  16. Electron induced inelastic and ionization cross section for plasma modeling

    NASA Astrophysics Data System (ADS)

    Verma, Pankaj; Mahato, Dibyendu; Kaur, Jaspreet; Antony, Bobby

    2016-09-01

    The present paper reports electron impact total inelastic and ionization cross section for silicon, germanium, and tin tetrahalides at energies varying from ionization threshold of the target to 5000 eV. These cross section data over a wide energy domain are very essential to understand the physico-chemical processes involved in various environments such as plasma modeling, semiconductor etching, atmospheric sciences, biological sciences, and radiation physics. However, the cross section data on the above mentioned molecules are scarce. In the present article, we report the computation of total inelastic cross section using spherical complex optical potential formalism and the estimation of ionization cross section through a semi-empirical method. The present ionization cross section result obtained for SiCl4 shows excellent agreement with previous measurements, while other molecules have not yet been investigated experimentally. Present results show more consistent behaviour than previous theoretical estimates. Besides cross sections, we have also studied the correlation of maximum ionization cross section with the square root of the ratio of polarizability to ionization potential for the molecules with known polarizabilities. A linear relation is observed between these quantities. This correlation is used to obtain approximate polarizability volumes for SiBr4, SiI4, GeCl4, GeBr4, and GeI4 molecules.

  17. DPA Cross Section Library FermiDPA 1.0

    SciTech Connect

    Pronskikh, V. S.; Mokhov, N. V.

    2013-06-05

    DPA cross section library FermiDPA 1.0 based on the industry standard NRT model calculations is described. The library contains DPA cross sections for neutrons in the energy range 10$^{-5}$ eV 20 (150) MeV. Calculations used neutron-induced reaction cross sections from ENDFB-VII database of evaluated nuclear data. The NJOY99 nuclear data processing system's module HEATR was applied to calculate NRT model radiation damage cross sections. The FermiDPA 1.0 library is a database of 395 text files (for 395 known isotopes) with DPA cross sections. It is code-independent and can be implemented in any transport code.

  18. Temperature-dependent high resolution absorption cross sections of propane

    NASA Astrophysics Data System (ADS)

    Beale, Christopher A.; Hargreaves, Robert J.; Bernath, Peter F.

    2016-10-01

    High resolution (0.005 cm-1) absorption cross sections have been measured for pure propane (C3H8). These cross sections cover the 2550-3500 cm-1 region at five temperatures (from 296 to 700 K) and were measured using a Fourier transform spectrometer and a quartz cell heated by a tube furnace. Calibrations were made by comparison to the integrated cross sections of propane from the Pacific Northwest National Laboratory. These are the first high resolution absorption cross sections of propane for the 3 μm region at elevated temperatures. The cross sections provided may be used to monitor propane in combustion environments and in astronomical sources such as the auroral regions of Jupiter, brown dwarfs and exoplanets.

  19. Fission cross section measurements of actinides at LANSCE

    SciTech Connect

    Tovesson, Fredrik; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the {sup 235}U standard. Recent measurements include the {sup 233,238}U, {sup 239,242}Pu and {sup 243}Am neutron-induced fission cross sections. In this paper preliminary results for cross section data of {sup 243}Am and {sup 233}U will be presented.

  20. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Wine, P. H.

    1988-01-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  1. Analytical approximations for X-ray cross sections 3

    NASA Astrophysics Data System (ADS)

    Biggs, Frank; Lighthill, Ruth

    1988-08-01

    This report updates our previous work that provided analytical approximations to cross sections for both photoelectric absorption of photons by atoms and incoherent scattering of photons by atoms. This representation is convenient for use in programmable calculators and in computer programs to evaluate these cross sections numerically. The results apply to atoms of atomic numbers between 1 and 100 and for photon energies greater than or equal to 10 eV. The photoelectric cross sections are again approximated by four-term polynomials in reciprocal powers of the photon energy. There are now more fitting intervals, however, than were used previously. The incoherent-scattering cross sections are based on the Klein-Nishina relation, but use simpler approximate equations for efficient computer evaluation. We describe the averaging scheme for applying these atomic results to any composite material. The fitting coefficients are included in tables, and the cross sections are shown graphically.

  2. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    NASA Astrophysics Data System (ADS)

    Nicovich, J. M.; Wine, P. H.

    1988-03-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  3. Measuring and modeling the backscattering cross section of a leaf

    NASA Technical Reports Server (NTRS)

    Senior, T. B. A.; Sarabandi, K.; Ulaby, F. T.

    1987-01-01

    Leaves are a significant feature of any vegetation canopy, and for remote sensing purposes it is important to develop an effective model for predicting the scattering from a leaf. From measurements of the X band backscattering cross section of a coleus leaf in varying stages of dryness, it is shown that a uniform resistive sheet constitutes such a model for a planar leaf. The scattering is determined by the (complex) resistivity which is, in turn, entirely specified by the gravimetric moisture content of the leaf. Using an available asymptotic expression for the scattering from a rectangular resistive plate which includes, as a special case, a metallic plate whose resistivity is zero, the computed backscattering cross sections for both principal polarizations are found to be in excellent agreement with data measured for rectangular sections of leaves with different moisture contents. If the resistivity is sufficiently large, the asymptotic expressions do not differ significantly from the physical optics ones, and for naturally shaped leaves as well as rectangular sections, the physical optics approximation in conjunction with the resistive sheet model faithfully reproduces the dominant feataures of the scattering patterns under all moisture conditions.

  4. Antinucleus-Nucleus Cross Sections Implemented in Geant4

    SciTech Connect

    Uzhinsky, V.; Apostolakis, J.; Galoyan, A.; Folger, G.; Grichine, V.M.; Ivanchenko, V.N.; Wright, D.H.; /SLAC

    2012-04-26

    Cross sections of antinucleus ({bar p}, {bar d}, {bar t}, {sup 3}{ovr He}, {sup 4}{ovr He}) interactions with nuclei in the energy range 100 MeV/c to 1000 GeV/c per antinucleon are calculated in the Glauber approximation which provides good description of all known {bar p}Across sections. The results were obtained using a new parameterization of the total and elastic {bar p}p cross sections. Simple parameterizations of the antinucleus-nucleus cross sections are proposed for use in estimating the efficiency of antinucleus detection and tracking in cosmic rays and accelerator experiments. These parameterizations are implemented in the Geant4 toolkit.

  5. Manpower Planning Models. 2. Cross Sectional Models

    DTIC Science & Technology

    1975-03-01

    to investigate various retirement policies. Concepts developed in section 9 are used, and an early retirement scheme is investigated as an...flows between the 15 classes of faculty. We call this CL.. Table II.7 gives the fractional flows after an early retirement scheme has been...one used before early retirement , a is the one used after early retirement , and a. is the case where all appointments are made into non-tenure

  6. Effects of Cross-Sectional Shape, Solidity, and Distribution of Heat-Transfer Coefficient on the Torsional Stiffness of Thin Wings Subjected to Aerodynamic Heating

    NASA Technical Reports Server (NTRS)

    Thomson, Robert G.

    1959-01-01

    A study has been made of the effects of varying the shape, solidity, and heat-transfer coefficient of thin wings with regard to their influence on the torsional-stiffness reduction induced by aerodynamic heating. The variations in airfoil shape include blunting, flattening, and combined blunting and flattening of a solid wing of symmetrical double-wedge cross section. Hollow double-wedge wings of constant skin thickness with and without internal webs also are considered. The effects of heat-transfer coefficients appropriate for laminar and turbulent flow are investigated in addition to a step transition along the chord from a lower to a higher constant value of heat-transfer coefficient. From the results given it is concluded that the flattening of a solid double wedge decreases the reduction in torsional stiffness while slight degrees of blunting increase the loss. The influence of chordwise variations in heat-transfer coefficient due to turbulent and laminar boundary-layer flow on the torsional stiffness of solid wings is negligible. The effect of a step transition in heat-transfer coefficient along the chord of a solid wing can, however, become appreciable. The torsional-stiffness reduction of multiweb and hollow double-wedge wings is substantially less than that calculated for a solid wing subjected to the same heating conditions.

  7. Independent and Combined Effects of Physical Activity and Sedentary Behavior on Blood Pressure in Adolescents: Gender Differences in Two Cross-Sectional Studies

    PubMed Central

    de Moraes, Augusto César Ferreira; Carvalho, Heráclito Barbosa; Rey-López, Juan Pablo; Gracia-Marco, Luis; Beghin, Laurent; Kafatos, Anthony; Jiménez-Pavón, David; Molnar, Dénes; De Henauw, Stefaan; Manios, Yannis; Widhalm, Kurt; Ruiz, Jonatan R.; Ortega, Francisco B.; Sjöström, Michael; Polito, Angela; Pedrero-Chamizo, Raquel; Marcos, Ascensión; Gottrand, Frederic; Moreno, Luis A.

    2013-01-01

    Objectives To examine the independent and combined association of physical activity (PA) and sedentary behavior (SB) on both systolic (SBP) and diastolic blood pressure (DBP) in adolescents from two observational studies. Methods Participants from two cross-sectional studies, one conducted in Europe (n = 3,308; HELENA study) and the other in Brazil (n = 991; BRACAH study), were selected by complex sampling. Systolic and diastolic blood pressure (outcomes), PA and SB, both independently and combined, and potential confounders were analyzed. Associations were examined by multilevel linear regression. Results Performing the recommended amount of PA (≥60 min/d) attenuated the effect of SB on DBP in BRACAH study girls and in boys from both studies. In contrast, PA did not attenuate the effects of SB on the SBP of girls in the HELENA study. The combination of less than recommended levels of PA with 2–4 h/d of sedentary behavior was found to be associated with increased SBP in boys from both studies. Conclusions Meeting current PA recommendations could mediate the association between SB and DBP in both sexes. In boys, the joint effect of low levels of PA and excessive sedentary activity increases SBP levels. Longitudinal studies are required to confirm these findings. PMID:23650506

  8. Effectiveness of diagnostic screening tests in mass screening for COPD using a cooperative regional system in a region with heavy air pollution: a cross-sectional study

    PubMed Central

    Kotaki, Kenji; Ikeda, Hisao; Fukuda, Takeshi; Yuki, Fumiko; Hasuo, Kanehiro; Kawano, Yuhei; Kawasaki, Masayuki

    2017-01-01

    Objectives This study aimed to evaluate the effectiveness of a cooperative healthcare model for early detection and diagnosis of chronic obstructive pulmonary disease (COPD). Methods This was a cross-sectional observational study. We performed diagnosis of COPD at 4 public health centres in Ōmuta, Japan from March 2015 to March 2016, by adding screening for COPD at the time of routine medical evaluations. All patients aged over 40 years were eligible to participate. Among 397 eligible patients, 293 agreed to participate in the study. Results The estimated prevalence of COPD in Ōmuta was 10% among patients aged over 40 years and was 17% among smokers. Among those who were screened, over half of them had questionnaire scores over the cut-off of 17 points and decreased FEV1/FVC%, indicating COPD (p>0.05). 30 patients with suspected COPD were referred for further investigation at a local central hospital, but only 6 underwent further medical examinations. Conclusions The combination of a COPD questionnaire and medical examination is effective as a COPD screening tool. Future research should investigate behavioural interventions for smoking cessation that can be offered in a cooperative model, as well as for improving participation in COPD screening and for encouraging early presentation for treatment in those suspected of having COPD. PMID:28082365

  9. A Cross-Sectional Study on the Prevalence, Risk Factors, and Ill Effects of Internet Addiction Among Medical Students in Northeastern India

    PubMed Central

    Nath, Kamal; Naskar, Subrata; Victor, Robin

    2016-01-01

    Objective To evaluate Internet addiction among medical students in northeastern India and gain detailed knowledge about the prevalence, risk factors, and ill effects commonly associated with the disorder. Method The cross-sectional study sample comprised 188 medical students from Silchar Medical College and Hospital (Silchar, Assam, India). Students completed a sociodemographic form and an Internet use questionnaire, both created for this study, and the Young’s 20-Item Internet Addiction Test after they received brief instructions. Data were collected during a10-day period in June 2015. Results Of the 188 medical students, 46.8% were at increased risk of Internet addiction. Those who were found to be at increased risk had longer years of Internet exposure (P = .046) and always online status (P = .033). Also, among this group, the men were more prone to develop an online relationship. Excessive Internet usage also led to poor performance in college (P < .0001) and feeling moody, anxious, and depressed (P < .0001). Conclusions The ill effects of Internet addiction include withdrawal from real-life relationships, deterioration in academic activities, and a depressed and nervous mood. Internet use for nonacademic purposes is increasing among students, thus there is an immediate need for strict supervision and monitoring at the institutional level. The possibility of becoming addicted to the Internet should be emphasized to students and their parents through awareness campaigns so that interventions and restrictions can be implemented at the individual and family levels. PMID:27486546

  10. Cross Section Sensitivity and Propagated Errors in HZE Exposures

    NASA Technical Reports Server (NTRS)

    Heinbockel, John H.; Wilson, John W.; Blatnig, Steve R.; Qualls, Garry D.; Badavi, Francis F.; Cucinotta, Francis A.

    2005-01-01

    It has long been recognized that galactic cosmic rays are of such high energy that they tend to pass through available shielding materials resulting in exposure of astronauts and equipment within space vehicles and habitats. Any protection provided by shielding materials result not so much from stopping such particles but by changing their physical character in interaction with shielding material nuclei forming, hopefully, less dangerous species. Clearly, the fidelity of the nuclear cross-sections is essential to correct specification of shield design and sensitivity to cross-section error is important in guiding experimental validation of cross-section models and database. We examine the Boltzmann transport equation which is used to calculate dose equivalent during solar minimum, with units (cSv/yr), associated with various depths of shielding materials. The dose equivalent is a weighted sum of contributions from neutrons, protons, light ions, medium ions and heavy ions. We investigate the sensitivity of dose equivalent calculations due to errors in nuclear fragmentation cross-sections. We do this error analysis for all possible projectile-fragment combinations (14,365 such combinations) to estimate the sensitivity of the shielding calculations to errors in the nuclear fragmentation cross-sections. Numerical differentiation with respect to the cross-sections will be evaluated in a broad class of materials including polyethylene, aluminum and copper. We will identify the most important cross-sections for further experimental study and evaluate their impact on propagated errors in shielding estimates.

  11. Diffusion cross sections for potassium ? and ? levels in rare gases

    NASA Astrophysics Data System (ADS)

    Yahyaei-Moayyed, F.; Hickman, A. P.; Streater, A. D.

    1996-02-01

    We have used a light-induced drift (LID) experiment to determine ratios of cross sections for diffusion of potassium in the excited 0953-4075/29/3/011/img3, 0953-4075/29/3/011/img4 and the ground 0953-4075/29/3/011/img5 levels in five rare gases. The measured ratios are combined with the ground-state cross sections and statistically averaged excited cross sections, available from a previously reported light induced diffusive pulling experiment, to obtain the absolute cross sections for individual fine structure levels. We also report calculated cross sections based on available potential curves and a coupled-channel theory. Rough qualitative agreement is generally found between the absolute cross sections inferred from experiment and the theoretical values. The light-induced drift experiments, however, measure ratios of cross section differences that are highly sensitive to the potential curves. It is found that the available potential curves are not adequate for predicting these measured ratios.

  12. Electron impact ionization cross sections of beryllium-tungsten clusters*

    NASA Astrophysics Data System (ADS)

    Sukuba, Ivan; Kaiser, Alexander; Huber, Stefan E.; Urban, Jan; Probst, Michael

    2016-01-01

    We report calculated electron impact ionization cross sections (EICSs) of beryllium-tungsten clusters, BenW with n = 1,...,12, from the ionization threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. The positions of the maxima of DM and BEB cross sections are mostly close to each other. The DM cross sections are more sensitive with respect to the cluster size. For the clusters smaller than Be4W they yield smaller cross sections than BEB and vice versa larger cross sections than BEB for clusters larger than Be6W. The maximum cross section values for the singlet-spin groundstate clusters range from 7.0 × 10-16 cm2 at 28 eV (BeW) to 54.2 × 10-16 cm2 at 43 eV (Be12W) for the DM cross sections and from 13.5 × 10-16 cm2 at 43 eV (BeW) to 38.9 × 10-16 cm2 at 43 eV (Be12W) for the BEB cross sections. Differences of the EICSs in different isomers and between singlet and triplet states are also explored. Both the DM and BEB cross sections could be fitted perfectly to a simple expression used in modeling and simulation codes in the framework of nuclear fusion research. Contribution to the Topical Issue "Atomic Cluster Collisions (7th International Symposium)", edited by Gerardo Delgado Barrio, Andrey Solov'Yov, Pablo Villarreal, Rita Prosmiti.Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2015-60583-7

  13. Review of electron impact excitation cross sections for copper atom

    SciTech Connect

    Winter, N.W.; Hazi, A.U.

    1982-02-01

    Excitation of atomic copper by electron impact plays an important role in the copper vapor laser and accurate cross sections are needed for understanding and modeling laser performance. During the past seven years, there have been several attempts to normalize the relative elastic and inelastic cross sections measured by Trajmar and coworkers. However, each of these efforts have yielded different cross sections, and the uncertainty in the correct normalization of the data has been a source of confusion and concern for the kinetic modeling efforts. This difficulty has motivated us to review previous work on the electron impact excitation of copper atom and to perform new calculations of the inelastic cross sections using the impact parameter method. In this memorandum we review the previous attempts to normalize the experimental data and provide a critical assessment of the accuracy of the resulting cross sections. We also present new theoretical cross sections for the electron impact excitation of the /sup 2/S ..-->.. /sup 2/P/sup 0/ and /sup 2/S ..-->.. /sup 2/D transitions in copper. When the experimental cross sections are renormalized to the results of the impact parameter calculations, they are a factor of three smaller than those published in the latest paper of Trajmar et. al. At impact energies above 60 eV the excitation cross sections obtained with the impact parameter method agree well with the results of the very recent, unpublished, close-coupling calculations of Henry. This agreement suggests that the present normalization of the experimental cross sections is probably the most reliable one obtained to date.

  14. Effectiveness of Albendazole for Hookworm Varies Widely by Community and Correlates with Nutritional Factors: A Cross-Sectional Study of School-Age Children in Ghana.

    PubMed

    Humphries, Debbie; Nguyen, Sara; Kumar, Sunny; Quagraine, Josephine E; Otchere, Joseph; Harrison, Lisa M; Wilson, Michael; Cappello, Michael

    2017-02-08

    Mass drug administration (MDA) targeting school-age children is recommended by the World Health Organization for the global control of soil-transmitted helminth (STH) infections. Although considered safe and cost-effective to deliver, benzimidazole anthelminthics are variably effective against the three most common STHs, and widespread use has raised concern about the potential for emerging resistance. To identify factors mediating response to albendazole, we conducted a cross-sectional study of hookworm infection in the Kintampo North Municipality of Ghana in 2011. Among 140 school-age children residing in five contiguous communities, the hookworm prevalence was 59% (82/140). The overall cure rate following administration of single-dose albendazole (400 mg) was 35% (27/76), with a community-wide fecal egg reduction rate (ERR) of 61% (95% confidence interval: 51.8-71.1). Significant disparities were observed in albendazole effectiveness by community, with a cure rate as low as 0% (N = 24) in Jato Akuraa and ERRs ranging from 53% to 95% across the five study sites. Individual host factors associated with response to deworming treatment included time since last meal, pretreatment blood hemoglobin level, and mid-upper arm circumference. These data demonstrate significant community-level variation in the effectiveness of albendazole, even among populations living in close proximity. Identification of host factors that influence response to albendazole, most notably the timing of drug administration and nutritional factors, creates an opportunity to enhance the effectiveness of deworming through targeted interventions. These findings also demonstrate the importance of measuring anthelminthic response as part of the monitoring and evaluation of community-based deworming programs.

  15. A cross-sectional study of changes in markers of immunological effects and lung health due to exposure to multi-walled carbon nanotubes.

    PubMed

    Vlaanderen, Jelle; Pronk, Anjoeka; Rothman, Nathaniel; Hildesheim, Allan; Silverman, Debra; Hosgood, H Dean; Spaan, Suzanne; Kuijpers, Eelco; Godderis, Lode; Hoet, Peter; Lan, Qing; Vermeulen, Roel

    2017-03-16

    Background Multi Wall Carbon nanotubes (MWCNTs) are manufactured nanomaterials to which workers and the general population will be increasingly exposed in coming years. Little is known about potential human health effects of exposure to MWCNTs, but effects on the lung and the immune system have been reported in animal and mechanistic studies. Objectives We conducted a cross-sectional study to assess the association between occupational exposure to MWCNTs and effects on lung health and the immune system. Methods We assessed fifty-one immune markers and three pneumoproteins in serum, complete blood cell counts (CBC), fractional exhaled nitric oxide (FENO), and lung function among twenty-two workers of a MWCNT producing facility and thirty-nine age- and gender-matched, unexposed controls. Measurements were repeated four months later among 16 workers also included in the first phase of the study. Regression analyses were adjusted for potentially confounding parameters age, body mass index, smoking, and sex and we explored potential confounding by other factors in sensitivity analyses. Results We observed significant upward trends for immune markers C-C motif ligand 20 (p = 0.005), basic fibroblast growth factor (p = 0.05), and soluble IL-1 receptor II (p = 0.0004) with increasing exposure to MWCNT. These effects were replicated in the second phase of the study and were robust to sensitivity analyses. We also observed differences in FENO and several CBC parameters between exposed and non-exposed, but no difference in lung function or the pneumoproteins. Conclusions We observed indications of early effects of occupational exposure to MWCNTs on lung health and the immune system.

  16. Assessment of knowledge of harmful effects and exposure to recreational music in college students of delhi: a cross sectional exploratory study.

    PubMed

    Gupta, Neelima; Sharma, Arun; Singh, P P; Goyal, Abhishek; Sao, Rahul

    2014-09-01

    Exposure to loud sounds results in a mild to profound degree of temporary or permanent hearing loss. Though occupational noise exposure remains the most commonly identified cause of noise-induced hearing loss, potentially hazardous noise can be encountered during recreational activities. Unfortunately not much attention is being given to the increasing trend of prolonged exposure to noisy environment, in the younger generation of Indians. The purpose of our study was to know the knowledge of college students about the harmful effects of loud music, prevailing practices with regard to exposure to recreational music and the subjective effects that this exposure is causing if any. Cross Sectional survey of College Students (n = 940), from randomly selected colleges of Delhi University. Majority of students listened to music using music-enabled phones; earphones were preferred and 56.6 % participants listened to music on a loud volume. Effects experienced due to loud sound were headache (58 %), inability to concentrate (48 %), and ringing sensation in the ear (41.8 %). Only 2.7 % respondents used ear protection device in loud volume settings. Twenty-three percent respondents complained of transient decreased hearing and other effects after exposure to loud music. 83.8 % knew that loud sound has harmful effect on hearing but still only 2.7 % used protection device. The survey indicates that we need to generate more such epidemiological data and follow up studies on the high risk group; so as to be able to convincingly sensitize the Indian young generation to take care of their hearing and the policy makers to have more information and education campaigns for this preventable cause of deafness.

  17. 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.

  18. Actinide neutron-induced fission cross section measurements at LANSCE

    SciTech Connect

    Tovesson, Fredrik K; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

  19. Nuclear reaction cross sections of exotic nuclei in the Glauber model for relativistic mean field densities

    SciTech Connect

    Patra, S. K.; Panda, R. N.; Arumugam, P.; Gupta, Raj K.

    2009-12-15

    We have calculated the total nuclear reaction cross sections of exotic nuclei in the framework of the Glauber model, using as inputs the standard relativistic mean field (RMF) densities and the densities obtained from the more recently developed effective-field-theory-motivated RMF (the E-RMF). Both light and heavy nuclei are taken as the representative targets, and the light neutron-rich nuclei as projectiles. We found the total nuclear reaction cross section to increase as a function of the mass number, for both the target and projectile nuclei. The differential nuclear elastic scattering cross sections are evaluated for some selected systems at various incident energies. We found a large dependence of the differential elastic scattering cross section on incident energy. Finally, we have applied the same formalism to calculate both the total nuclear reaction cross section and the differential nuclear elastic scattering cross section for the recently discussed superheavy nucleus with atomic number Z=122.

  20. Effect of media use on HIV/AIDS-related knowledge and condom use in sub-Saharan Africa: a cross-sectional study.

    PubMed

    Jung, Minsoo; Arya, Monisha; Viswanath, Kasisomayajula

    2013-01-01

    It is known that the level of HIV/AIDS-related knowledge and the degree of condom use varies by socioeconomic status (SES). However, there is limited research on the effect of mass media use on HIV/AIDS-related cognitive and behavioral outcomes in low-income countries and how it might influence the association between SES and HIV-related outcomes. We investigated the moderating effect of media use on the relationship between SES and HIV/AIDS-related knowledge and condom use in sub-Saharan Africa in terms of communication inequalities. Cross-sectional data from the Demographic Health Surveys from 13 sub-Saharan countries (2004-10) were pooled. Gender-stratified multivariable poisson regression of 151,209 women and 68,890 men were used to calculate adjusted relative ratios and 95% confidence intervals for the associations between SES, media use, HIV-related outcomes, and condom use. We found significant disparities in mass media use among people from different SES groups as well as among countries. Education and wealth are strongly and positively associated with awareness of HIV/AIDS and knowledge about transmission and prevention of HIV/AIDS and are significantly associated with condom use. These associations are attenuated when the use of various types of mass media is added to the models, with newspapers showing the strongest effect. The findings of this study suggest that media use has the potential to blunt the impact of socioeconomic status though not completely eliminate it. Thus, we need to pay attention to reducing communication inequalities among social groups and countries to moderate the effect of wealth and SES on HIV/AIDS.

  1. The effect of the Fermi resonance on the Raman scattering cross sections of the Fermi doublet ν1 and 2ν2 of liquid carbon disulfide in benzene.

    PubMed

    Li, Dong-Fei; Gao, Shu-Qin; Sun, Cheng-Lin; Jiang, Xiu-Lan; Li, Zuo-Wei

    2012-04-01

    The effect of the Fermi resonance (FR) on the Raman scattering cross sections (RSCSs) of the Fermi doublet ν1, 2ν2 of liquid CS2 in C6H6 using the method of changing the volume concentration of the solution is investigated. We have calculated the RSCSs of the Fermi doublet ν1, 2ν2 using Onsager's theory with the 992 cm(-1) Raman line of C6H6 as the internal standard. The result shows that the RSCS of the ν1 line decreases with decreasing the volume concentration of CS2, while that of the 2ν2 line unexpectedly increases. With decreasing the volume concentration of CS2, two main effects of the solvent effect (SE) and the FR in binary solution that can make the ν1, 2ν2 RSCSs change: the SE, as calculated, reduces both the ν1 and 2ν2 RSCSs; the FR plays a significant role in reducing the ν1 RSCS and enhancing the 2ν2 RSCS. In comparison with our previous investigation [J. Raman Spectrosc. 41 (2010) 776-779], it was found that the stronger the FR is, the more the RSCS of the ν1 decreases and the 2ν2 increases. Thus, we proposed that the result can be best explained by taking into account the effect of the FR on the RSCSs of the Fermi doublet. In addition, this paper also gives an explanation to the experimental results deviating from the theoretical results of the scattering coefficients of CS2 in solvent C6H6 as mentioned in Fini's paper.

  2. Systematics of isotopic production cross sections from interactions of relativistic 40Ca in hydrogen

    NASA Astrophysics Data System (ADS)

    Chen, C.-X.; Albergo, S.; Caccia, Z.; Costa, S.; Crawford, H. J.; Cronqvist, M.; Engelage, J.; Greiner, L.; Guzik, T. G.; Insolia, A.; Knott, C. N.; Lindstrom, P. J.; McMahon, M.; Mitchell, J. W.; Potenza, R.; Russo, G. V.; Soutoul, A.; Testard, O.; Tull, C. E.; Tuvé, C.; Waddington, C. J.; Webber, W. R.; Wefel, J. P.

    1997-09-01

    The isotopic production cross sections for 40Ca projectiles at 357, 565, and 763 MeV/nucleon interacting in a liquid hydrogen target have been measured by the Transport Collaboration at the LBL HISS facility. The systematics of these cross sections are studied, and the results indicate that nuclear structure effects are present in the isotope production process during the relativistic collisions. The newly measured cross sections are also compared with those predicted by semiempirical and parametric formulas, but the predictions do not fully describe the systematics such as the energy dependence. The consequences of the cross section systematics in galactic cosmic ray studies are also discussed.

  3. Photoionization and photoabsorption cross sections for the aluminum iso-nuclear sequence

    SciTech Connect

    Witthoeft, M.C.; García, J.; Kallman, T.R.; Palmeri, P.; Quinet, P.

    2013-01-15

    K-shell photoionization and photoabsorption cross sections are presented for Li-like to Na-like Al. The calculations are performed using the Breit–Pauli R-matrix method where the effects of radiation and Auger dampings are included. We provide electronic data files for the raw cross sections as well as those convolved with a Gaussian of width ΔE/E=10{sup −4}. In addition to total cross sections for photoabsorption and photoionization, partial cross sections are available for photoionization.

  4. Prospective cross-sectional study using questionnaire to assess the effect of a different nomenclature for psychiatric illnesses on the perception of these diseases by university students.

    PubMed

    Lau, Jerome; Kam, L S; Tsang, Y M; Chow, Boris C K; Fang, Y Y; Lam, K W; Lam, Y T; Li, Y Y; Wong, Cally H S

    2012-10-01

    OBJECTIVE. To assess the effect of a difference in nomenclature for psychiatric illness on perceptions of university students. DESIGN. Cross-sectional study. SETTING. Three local universities in Hong Kong. PARTICIPANTS. A total of 201 university students (undergraduates or postgraduates) were interviewed with a questionnaire. MAIN OUTCOME MEASURES. Score difference between the new and old nomenclature of each disease for each question of the questionnaire, using a 5-point Likert scale and an integrated score difference for each disease. RESULTS. Of the seven diseases investigated, six yielded a significant yet mild increase in positive perceptions with the new nomenclature. These diseases included schizophrenia (integrated score difference: +0.158, P<0.001), neurasthenia (integrated score difference: +0.117, P<0.001), paranoia (integrated score difference: +0.209, P<0.001), personality disorder (integrated score difference: +0.282, P<0.001), attention deficit hyperactivity disorder (integrated score difference: +0.086, P=0.005), and bipolar disorder (integrated score difference: +0.154, P<0.001). Epilepsy showed a negative perception with its new nomenclature (integrated score difference: -0.119, P<0.001). CONCLUSIONS. The new nomenclature system for psychiatric diseases achieves more positive perceptions among the university students than the old nomenclature. Epilepsy was the exception for which the old nomenclature conferred a more positive perception. Further studies on this topic involving a more general population should be advocated to confirm the improvements in perception with the new naming system for psychiatric diseases.

  5. Effects of processing parameters on the extrusion by continuous variable cross-section direct extrusion with 7A09 aluminium alloy

    NASA Astrophysics Data System (ADS)

    Li, Feng; Wu, Hongbin; Qin, Minghan

    2016-02-01

    In order to study the effects of processing parameters on the continuous variable cross-section direct extrusion (CVCDE), taking 7A09 aluminium alloy for example, the extrusion speed and forming temperature and the friction factor as key processing parameters are applied to research by finite element (FE) simulation. The research result showed that the extrusion speed had a significant influence on the maximum temperature of the billet, at the same time, both decreasing the friction factor and increasing forming temperature within a certain range were beneficial to reduce extrusion load. Both forming temperature and the extrusion speed were inversely linked to extrusion load, but the friction factor was directly proportional to extrusion load. Forming temperature had a far more important influence on extrusion load by comparison: when forming temperature increased from 380∘ to 430∘C, the peak value of extrusion load decreased by 25.6% and the flow uniformity of extruded product got improved. The process window based on both the press limit and surface defects limit was established and the most reasonable forming temperature was 405∘C under this process condition, which provided theoretical basis for formulation process of 7A09 aluminium alloy on the CVCDE extrusion.

  6. A genetic algorithm to reduce stream channel cross section data

    USGS Publications Warehouse

    Berenbrock, C.

    2006-01-01

    A genetic algorithm (GA) was used to reduce cross section data for a hypothetical example consisting of 41 data points and for 10 cross sections on the Kootenai River. The number of data points for the Kootenai River cross sections ranged from about 500 to more than 2,500. The GA was applied to reduce the number of data points to a manageable dataset because most models and other software require fewer than 100 data points for management, manipulation, and analysis. Results indicated that the program successfully reduced the data. Fitness values from the genetic algorithm were lower (better) than those in a previous study that used standard procedures of reducing the cross section data. On average, fitnesses were 29 percent lower, and several were about 50 percent lower. Results also showed that cross sections produced by the genetic algorithm were representative of the original section and that near-optimal results could be obtained in a single run, even for large problems. Other data also can be reduced in a method similar to that for cross section data.

  7. Coriolis coupling effects in the calculation of state-to-state integral and differential cross sections for the H+D2 reaction.

    PubMed

    Chu, Tian-Shu; Han, Ke-Li; Hankel, Marlies; Balint-Kurti, Gabriel G

    2007-06-07

    The quantum wavepacket parallel computational code DIFFREALWAVE is used to calculate state-to-state integral and differential cross sections for the title reaction on the BKMP2 surface in the total energy range of 0.4-1.2 eV with D2 initially in its ground vibrational-rotational state. The role of Coriolis couplings in the state-to-state quantum calculations is examined in detail. Comparison of the results from calculations including the full Coriolis coupling and those using the centrifugal sudden approximation demonstrates that both the energy dependence and the angular dependence of the calculated cross sections are extremely sensitive to the Coriolis coupling, thus emphasizing the importance of including it correctly in an accurate state-to-state calculation.

  8. Buckling and vibration analysis of a simply supported column with a piecewise constant cross section

    NASA Technical Reports Server (NTRS)

    Lake, Mark S.; Mikulas, Martin M., Jr.

    1991-01-01

    An analysis and sample results for the lateral buckling and vibration of a compressively loaded column is presented whose cross section is piecewise constant along its length. The column is symmetric about its mid-span and consists of three sections, the center section having a stiffer cross section than the two identical end sections. Buckling and vibration characteristics of the column are determined from numerical solution of the exact eigenvalue problems. Parametric structural efficiency analyses are performed using a nondimensionalized set of governing equations to determine the optimum ratio between the lengths of the center section and the outer sections based on both buckling load and vibration frequency requirements. In these analyses, two relationships exist. One is between cross-sectional mass and the cross section, and the other is a high-efficiency scheme. The effect of axial load on vibration frequency is also examined and compared with that of a uniform column.

  9. 28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE ...

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

    28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE INTERNAL STRUCTURE OF THE OVEN. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

  10. 12. CLOSEUP VIEW OF CROSS SECTION OF SPILLWAY FIFTY FEET ...

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

    12. CLOSE-UP VIEW OF CROSS SECTION OF SPILLWAY FIFTY FEET FROM LAKESHORE, SHOWING REMAINS OF SPILLWAY TIMBERS, LOOKING WEST - Three Bears Lake & Dams, North of Marias Pass, East Glacier Park, Glacier County, MT

  11. Section B, general view of steel cross with new World ...

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

    Section B, general view of steel cross with new World Trade Center 7 in background, looking northwest. (BH) - World Trade Center Site, Bounded by Vesey, Church, Liberty Streets, & Route 9A, New York County, NY

  12. Stellar (n ,γ ) cross sections of 23Na

    NASA Astrophysics Data System (ADS)

    Uberseder, E.; Heil, M.; Käppeler, F.; Lederer, C.; Mengoni, A.; Bisterzo, S.; Pignatari, M.; Wiescher, M.

    2017-02-01

    The cross section of the 23Na(n ,γ )24Na reaction was measured via the activation method at the Karlsruhe 3.7 MV Van de Graaff accelerator. NaCl samples were exposed to quasistellar neutron spectra at k T =5.1 and 25 keV produced via the 18O(p ,n )18F and 7Li(p ,n )7Be reactions, respectively. The derived capture cross sections <σ> kT =5 keV=9.1 ±0.3 mb and <σ> kT =25 keV=2.03 ±0.05 mb are significantly lower than reported in literature. These results were used to substantially revise the radiative width of the first 23Na resonance and to establish an improved set of Maxwellian average cross sections. The implications of the lower capture cross section for current models of s -process nucleosynthesis are discussed.

  13. 8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT ...

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

    8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT THAT SHOWS THE TRENCHING AND 1960 PIPELINE CORRIDOR BETWEEN THE WALL SEGMENTS, LOOKING WEST-NORTHWEST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  14. Photocopy of "sheet 6 of 8" showing cross section of ...

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

    Photocopy of "sheet 6 of 8" showing cross section of house, front elevation, fire finder stand, hip roof cap, and shiplap roof sheathing. - Badger Mountain Lookout, .125 mile northwest of Badger Mountain summit, East Wenatchee, Douglas County, WA

  15. Local Deplanation Of Double Reinforced Beam Cross Section Under Bending

    NASA Astrophysics Data System (ADS)

    Baltov, Anguel; Yanakieva, Ana

    2015-12-01

    Bending of beams, double reinforced by means of thin composite layers, is considered in the study. Approximate numerical solution is proposed, considering transitional boundary areas, where smooth quadratic transition of the elasticity modulus and deformations take place. Deplanation of the cross section is also accounted for in the areas. Their thickness is found equalizing the total stiffness of the cross section and the layer stiffness. Deplanation of the cross section of the transitional area is determined via the longitudinal deformation in the reinforcing layer, accounting for the equilibrium between the internal and the external moment, generated by the longitudinal stresses in the cross section. A numerical example is given as an illustration demonstrating model's plausibility. The model allows the design and the calculation of recycled concrete beams double reinforced by means of thin layers. The approach is in agreement with modern design of nearly zero energy buildings (NZEB).

  16. A new technique for dosimetry reaction cross-section evaluation

    SciTech Connect

    Badikov, S.A.

    2011-07-01

    Document available in abstract form only, full text of document follows: An objective of this paper is a unification of the procedure for dosimetry reaction cross-section evaluation. A set of requirements for the unified evaluation procedure is presented. A new code (ORTHO) was developed in order to meet these requirements. A statistical model, an algorithm, and the basic formulae employed in the code are described. The code was used for Ti48(n,p) reaction cross-section evaluation. The results of the evaluation are compared to International Reactor Dosimetry File (IRDF)-2002 data. The evaluated cross-sections and their correlations from this work are in good agreement with the IRDF-2002 evaluated data, whereas the uncertainties of the evaluated cross-sections are inconsistent. (authors)

  17. 4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR ...

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

    4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR FACINGS LINED WITH RUBBLE BACKING AND EARTH INFILL, LOOKING EAST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  18. Theory in Evaluation of Actinide Fission and Capture Cross Sections

    SciTech Connect

    Lynn, J. Eric

    2005-05-24

    We discuss the possibilities and limitations of the use of theory as a tool in the evaluation of actinide fission and capture cross sections. We consider especially the target 235U as an example. We emphasize the roles of intermediate structure in the fission cross section and of level width fluctuations in both intermediate structure and fine structure, noting that these lead to a breakdown of Hauser-Feshbach theory at sub-barrier and near-barrier energies. At higher energies (where fluctuation-averaged Hauser-Feshbach theory is applicable) semi-quantitative and intuitive representations of transition state spectra and barrier level density functions have to be tested against experimental data wherever these are available. Adjustment of the fission cross section against inelastic scattering to the much better known levels of the residual nucleus should then lead to a fairly sound estimate of the capture cross section. We compare such estimates with evaluated and experimental data for 235U.

  19. Superstructure Main Bridge, Cross Sections, Cantilever Structure Huey ...

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

    Superstructure - Main Bridge, Cross Sections, Cantilever Structure - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  20. Scaling Cross Sections for Ion-atom Impact Ionization

    SciTech Connect

    Igor D. Kaganovich; Edward Startsev; Ronald C. Davidson

    2003-06-06

    The values of ion-atom ionization cross sections are frequently needed for many applications that utilize the propagation of fast ions through matter. When experimental data and theoretical calculations are not available, approximate formulas are frequently used. This paper briefly summarizes the most important theoretical results and approaches to cross section calculations in order to place the discussion in historical perspective and offer a concise introduction to the topic. Based on experimental data and theoretical predictions, a new fit for ionization cross sections is proposed. The range of validity and accuracy of several frequently used approximations (classical trajectory, the Born approximation, and so forth) are discussed using, as examples, the ionization cross sections of hydrogen and helium atoms by various fully stripped ions.

  1. 36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER ...

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

    36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER PLANT, LOOKING NORTH. ONLY TWO OF THE THREE UNITS ARE VISIBLE - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  2. 20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY ...

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

    20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY SUPERSTRUCTURE AND CONCRETE PLACEMENT LINES August 2, 1927 - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  3. Radiative neutron capture cross sections on 176Lu at DANCE

    NASA Astrophysics Data System (ADS)

    Roig, O.; Jandel, M.; Méot, V.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.

    2016-03-01

    The cross section of the neutron capture reaction 176Lu(n ,γ ) has been measured for a wide incident neutron energy range with the Detector for Advanced Neutron Capture Experiments at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be (1912 ±132 ) b for one of the Lu natural isotopes, 176Lu. The resonance part was measured and compared to the Mughabghab's atlas using the R -matrix code, sammy. At higher neutron energies the measured cross sections are compared to ENDF/B-VII.1, JEFF-3.2, and BRC evaluated nuclear data. The Maxwellian averaged cross sections in a stellar plasma for thermal energies between 5 keV and 100 keV were extracted using these data.

  4. Automating the Modeling of the SEE Cross Section's Angular Dependence

    NASA Technical Reports Server (NTRS)

    Patterson, J. D.; Edmonds, L. D.

    2003-01-01

    An algorithm that automates the application of the alpha law in any SEE analysis is presented. This automation is essential for the widespread acceptance of the sophisticated cross section angular dependence model.

  5. Electron-Impact Total Ionization Cross Sections of Hydrocarbon Ions

    PubMed Central

    Irikura, Karl K.; Kim, Yong-Ki; Ali, M. A.

    2002-01-01

    The Binary-Encounter-Bethe (BEB) model for electron-impact total ionization cross sections has been applied to CH2+, CH3+, CH4+, C2H2+, C2H4+, C2H6+ and H3O+. The cross sections for the hydrocarbon ions are needed for modeling cool plasmas in fusion devices. No experimental data are available for direct comparison. Molecular constants to generate total ionization cross sections at arbitrary incident electron energies using the BEB formula are presented. A recent experimental result on the ionization of H3O+ is found to be almost 1/20 of the present theory at the cross section peak. PMID:27446718

  6. Effect of toe-spread-out exercise on hallux valgus angle and cross-sectional area of abductor hallucis muscle in subjects with hallux valgus

    PubMed Central

    Kim, Moon-Hwan; Yi, Chung-Hwi; Weon, Jong-Hyuck; Cynn, Heon-Seock; Jung, Do-Young; Kwon, Oh-Yun

    2015-01-01

    [Purpose] This study investigated whether the toe-spread-out exercise affects the hallux valgus angle, the cross-sectional area of the abductor hallucis muscle, and the hallux valgus angle during active abduction. [Subjects and Methods] Twenty-four subjects with hallux valgus were randomly assigned to orthosis and orthosis plus toe-spread-out exercise groups. The orthosis group wore the orthosis for 8 weeks, while the orthosis plus toe-spread-out group also performed the toe-spread-out exercise. The hallux valgus angle, the cross-sectional area of the abductor hallucis muscle, and the hallux valgus angle during active abduction were measured initially and after 8 weeks by radiography and ultrasonography. [Results] While there were no significant changes in the three parameters in the orthosis group, there were significant differences in the orthosis plus toe-spread-out exercise group after 8 weeks. In addition there were significant differences in the three measures between the two groups. [Conclusion] The toe-spread-out exercise reduces the hallux valgus angle and hallux valgus angle during active abduction, and increases the cross-sectional area of the abductor hallucis muscle. The toe-spread-out exercise is recommended for patients with mild to moderate hallux valgus. PMID:25995546

  7. A novel setup for the determination of absolute cross sections for low-energy electron induced strand breaks in oligonucleotides - The effect of the radiosensitizer 5-fluorouracil*

    NASA Astrophysics Data System (ADS)

    Rackwitz, Jenny; Ranković, Miloš Lj.; Milosavljević, Aleksandar R.; Bald, Ilko

    2017-02-01

    Low-energy electrons (LEEs) play an important role in DNA radiation damage. Here we present a method to quantify LEE induced strand breakage in well-defined oligonucleotide single strands in terms of absolute cross sections. An LEE irradiation setup covering electron energies <500 eV is constructed and optimized to irradiate DNA origami triangles carrying well-defined oligonucleotide target strands. Measurements are presented for 10.0 and 5.5 eV for different oligonucleotide targets. The determination of absolute strand break cross sections is performed by atomic force microscopy analysis. An accurate fluence determination ensures small margins of error of the determined absolute single strand break cross sections σ SSB . In this way, the influence of sequence modification with the radiosensitive 5-Fluorouracil (5FU) is studied using an absolute and relative data analysis. We demonstrate an increase in the strand break yields of 5FU containing oligonucleotides by a factor of 1.5 to 1.6 compared with non-modified oligonucleotide sequences when irradiated with 10 eV electrons.

  8. Nuclear Cross Sections for Space Radiation Applications

    NASA Technical Reports Server (NTRS)

    Werneth, C. M.; Maung, K. M.; Ford, W. P.; Norbury, J. W.; Vera, M. D.

    2015-01-01

    The eikonal, partial wave (PW) Lippmann-Schwinger, and three-dimensional Lippmann-Schwinger (LS3D) methods are compared for nuclear reactions that are relevant for space radiation applications. Numerical convergence of the eikonal method is readily achieved when exact formulas of the optical potential are used for light nuclei (A = 16) and the momentum-space optical potential is used for heavier nuclei. The PW solution method is known to be numerically unstable for systems that require a large number of partial waves, and, as a result, the LS3D method is employed. The effect of relativistic kinematics is studied with the PW and LS3D methods and is compared to eikonal results. It is recommended that the LS3D method be used for high energy nucleon-nucleus reactions and nucleus-nucleus reactions at all energies because of its rapid numerical convergence and stability for both non-relativistic and relativistic kinematics.

  9. On the interweaving of partial cross sections of different parity

    NASA Technical Reports Server (NTRS)

    Devries, P. L.; George, T. F.

    1979-01-01

    Partial cross sections of definite parity, calculated for electronic-rotational energy transfer in the F +H2 collision system, interweave with increasing total angular momentum J. An explanation, in terms of diabatic curve crossings induced by the centrifugal potential in the body-fixed coordinate system, predicts the interweaving to occur only in systems having half-integer J.

  10. Top Quark Pair Production Cross Section at the Tevatron

    SciTech Connect

    Peters, Reinhild Yvonne

    2015-09-25

    The top quark, discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton antiproton collider at Fermilab, has undergone intense studies in the last 20 years. Currently, CDF and D0 converge on their measurements of top-antitop quark production cross sections using the full Tevatron data sample. In these proceedings, the latest results on inclusive and differential measurements of top-antitop quark production cross sections at the Tevatron are reported.

  11. Differential cross sections for positron-xenon elastic scattering

    SciTech Connect

    Marler, J. P.; Surko, C. M.; McEachran, R. P.; Stauffer, A. D.

    2006-06-15

    Absolute measurements of differential cross sections for the elastic scattering of positrons from xenon are made at 2, 5 and 8 eV using a trap-based beam and the technique of measuring scattering cross sections in a strong magnetic field. Calculations are carried out using the relativistic Dirac equations with a static plus polarization potential. Generally good absolute agreement is found between experiment and theory.

  12. A Cross-Sectional Comparison of Army Advertising Attributes

    DTIC Science & Technology

    1990-11-01

    that identifies the needs and characteristics of individuals in the Armys’ prime market , as well as their exposure to Army advertising . One way the Army...U.S. Army Research Institute for the Behavioral and Social Sciences N Research Report 1578 A Cross-Sectional Comparison I of Army Advertising ...62785A 791 2105 H01 11. TITLE (Include Security Classification) A Cross-Sectional Comparison of Army Advertising Attributes 12. PERSONAL AUTHOR(S

  13. Enhancing the optical cross section of quantum antenna

    NASA Astrophysics Data System (ADS)

    Liu, Jingfeng; Zhou, Ming; Ying, Lei; Chen, Xuewen; Yu, Zongfu

    2017-01-01

    The classical radio-frequency antenna theory indicates that large cross sections can be realized through directional radiation. In this paper, a similar principle is applied in quantum systems, in which quantum antennas, constructed by a cluster of quantum two-level systems, explore the collective excitation of two-level systems to realize large directivity. Both the optical cross section and the coherent time can be dramatically enhanced in free space, far exceeding the case of a single two-level system.

  14. Experimental nuclear cross sections for spacecraft shield analysis

    NASA Technical Reports Server (NTRS)

    Peelle, R. W.

    1972-01-01

    Experiments have been performed to validate and to supplement the intranuclear cascade model as a method for estimating cross sections of importance to spacecraft shield design. The experimental situation is inconclusive particularly for neutron-producing reactions, but is relatively sound for reaction cross sections and for proton spectra at several hundred MeV at medium forward angles. Secondary photon contributions are imprecisely known.

  15. Photoproduction models for total cross section and shower development

    NASA Astrophysics Data System (ADS)

    Cornet, Fernando; Garcia Canal, Carlos; Grau, Agnes; Pancheri, Giulia; Sciutto, Sergio

    2015-08-01

    A model for the total photoproduction cross section, based on the ansatz that resummation of infrared gluons limits the rise induced by QCD minijets in all the total cross-sections, is used to simulate extended air showers initiated by cosmic rays with the AIRES simulation program. The impact on common shower observables, especially those related with muon production, is analysed and compared with the corresponding results obtained with previous photoproduction models.

  16. Absorption cross sections of the ClO dimer

    NASA Technical Reports Server (NTRS)

    Huder, K. J.; DeMore, W. B.

    1995-01-01

    The absorption cross sections of the ClO dimer, ClOOCl, are important to the photochemistry of ozone depletion in the Antarctic. In this work, new measurements were made of the dimer cross sections at 195 K. the results yield somewhat lower values in the long wavelength region, compared to those currently recommended in the NASA data evaluation (JPL 94-26). The corresponding solar photodissociation rates in the Antarctic are reduced by about 40%.

  17. Positronium beam production and scattering cross-sections

    NASA Astrophysics Data System (ADS)

    Leslie, Dawn Elizabeth

    In this work, the efficiency for the production of a monoenergetic positronium beam via the charge-exchange reaction of a positron beam in a gaseous target has been determined for molecular hydrogen and molecular nitrogen. In the case of molecular nitrogen, it has been found that the energy range over which a useful intensity of collimated positronium may be produced can be extended to 250eV, 100eV higher than previously achieved. This should enable measurements of the total and partial positronium cross-sections at correspondingly higher energies, where target inelastic effects are expected to be significant A recent measurement of the integrated positronium formation cross-section for xenon found a larger yield of positronium atoms compared to the other noble gases. A shoulder was also seen 10eV above the peak and it was suggested that this might be due to the production of positronium in an excited state. These findings have provided an incentive to investigate the collimated positronium production efficiency from xenon, which has been found to be surprisingly low. The quantum state of the beam atoms has also been found to be dominantly ground state. Possible reasons for these findings are discussed Total cross-sections for positronium-gas scattering have been extracted from the measurements of the positronium beam production efficiency for both molecular nitrogen and xenon. These quantities have also been determined directly by measuring the intensity of the positronium beam transmitted through a gas cell via the Beer-Lambert Law. A good consistency is found between the values obtained using this method and those determined indirectly. Recently, measurements have been made of the absolute integrated cross-section for the fragmentation of positronium in collision with helium atoms, along with the longitudinal energy distributions of the residual positrons in the energy range -Ep/=13-33eV. Measurements of the latter indicate a peak close to half the residual

  18. Photodissociation cross section of ClOOCl at 330 nm.

    PubMed

    Jin, Bing; Chen, I-Cheng; Huang, Wen-Tsung; Lien, Chien-Yu; Guchhait, Nikhil; Lin, Jim J

    2010-04-15

    The photolysis rate of ClOOCl is crucial in the catalytic destruction of polar stratospheric ozone. In this work, we determined the photodissociation cross section of ClOOCl at 330 nm with a molecular beam and with mass-resolved detection. The photodissociation cross section is the product of the absorption cross section and the dissociation quantum yield. We formed an effusive molecular beam of ClOOCl at a nozzle temperature of 200 or 250 K and determined its photodissociation probability by measuring the decrease of the ClOOCl intensity upon laser irradiation. By comparing with a reference molecule (Cl(2)), of which the absorption cross section and dissociation quantum yield are well-known, we determined the absolute photodissociation cross section of ClOOCl at 330 nm to be (2.31 +/- 0.11) x 10(-19) cm(2) at 200 K and (2.47 +/- 0.12) x 10(-19) cm(2) at 250 K. Impurity interference has been a well-recognized problem in conventional spectroscopic studies of ClOOCl; our mass-resolved measurement directly overcomes such a problem. This measurement of the ClOOCl photolysis cross section at 330 nm is particularly useful in constraining its atmospheric photolysis rate, which in the polar stratosphere peaks near this wavelength.

  19. General Constraints on Cross Sections Deduced from Surrogate Reactions

    SciTech Connect

    Younes, W

    2003-08-14

    Cross sections that cannot be measured in the laboratory, e.g. because the target lifetime is too short, can be inferred indirectly from a different reaction forming the same compound system, but with a more accessible beam/target combination (the ''surrogate-reaction'' technique). The reactions share the same compound system and a common decay mechanism, but they involve different formation processes. Therefore, an implicit constraint is imposed on the inferred cross section deduced from the measured surrogate-reaction data, through the common decay mechanism. In this paper, the mathematical consequences of this implicit constraint are investigated. General formulas are derived from upper and lower bounds on the inferred cross section, estimated from surrogate data in a procedure which does not require any modeling of the common decay process. As an example, the formulas developed here are applied to the case of the {sup 235}U(n,f) cross section, deduced from {sup 234}U(t,pf) surrogate data. The calculated bounds are not very tight in this particular case. However, by introducing a few qualitative assumptions about the physics of the fission process, meaningful bounds on the deduced cross section are obtained. Upper and lower limits for the cross-section ratio of the (n,f) reaction on the {sup 235}U isomer at E{sub x} = 77 eV relative to the (n,f) reaction on the ground state are also calculated. The generalization of this technique to other surrogate reactions is discussed.

  20. Electron cross-sections and transport in liquids and biomolecules

    NASA Astrophysics Data System (ADS)

    White, Ronald; Casey, M.; Cocks, D.; Konvalov, D.; Brunger, M. J.; Garcia, G.; Petrovic, Z.; McEachran, R.; Buckman, S. J.; de Urquijo, J.

    2016-09-01

    Modelling of electron induced processes in plasma medicine and radiation damage is reliant on accurate self-consistent sets of cross-sections for electrons in tissue. These cross-sections (and associated transport theory) must accurately account not only the electron-biomolecule interactions but also for the soft-condensed nature of tissue. In this presentation, we report on recent swarm experiments for electrons in gaseous water and tetrahydrofuran using the pulsed-Townsend experiment, and the associated development of self-consistent cross-section sets that arise from them. We also report on the necessary modifications to gas-phase cross-sections required to accurately treat electron transport in liquids. These modifications involve the treatment of coherent scattering and screening of the electron interaction potential as well as the development of a new transport theory to accommodate these cross-sections. The accuracy of the ab-initio cross-sections is highlighted through comparison of theory and experiment for electrons in liquid argon and xenon.

  1. Status of the Neutron Cross-Section Standards Database

    NASA Astrophysics Data System (ADS)

    Hambsch, Franz-Josef; Carlson, Allan D.; Vonach, Herbert

    2005-05-01

    A new evaluation of the neutron cross-section standards is now underway. This evaluation has been supported by the Working Party on International Evaluation Cooperation (WPEC), the Cross Section Evaluation Working Group (CSEWG), and an International Atomic Energy Agency Coordinated Research Program (CRP). The CRP has had the dominant role in producing these evaluations. An important goal is to produce the standards needed for the upcoming new ENDF/B-VII library. Since most neutron cross-section measurements are made relative to neutron cross-section standards, the standards evaluation is of crucial importance. The standard reactions to be evaluated are: H(n,n), 3He(n,p), 6Li(n,t), 10B(n,α), 10B(n,α1γ), C(n,n), Au(n,γ), 235U(n,f), and 238U(n,f). These standards should receive international acceptance to ensure that all evaluation projects use the same set of standards. The last complete evaluation of the standards dates back almost 20 years. In the meantime quite a number of new and improved measurements have occurred for the cross-section standards. International efforts are presently underway to update the experimental database and to improve the evaluation process. Due to the need for high-energy standards, the energy range is being extended to 200 MeV for some of the cross-section standards.

  2. Updated ozone absorption cross section will reduce air quality compliance

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Evans, M. J.; Lewis, A. C.

    2015-07-01

    Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been reevaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding fifty years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

  3. Updated ozone absorption cross section will reduce air quality compliance

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Evans, M. J.; Lewis, A. C.

    2015-12-01

    Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been re-evaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding 50 years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross-section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

  4. Measured data used in the Watusi cross-section sets

    SciTech Connect

    Mustafa, M; Nethaway, D R

    1999-02-09

    In this document we list the experimental data that were used to make up the major cross- section sets that we use in the Watusi code to calculate the amount of detector activation in device tests. In order to use experimental data to make up a cross-section set, it is often necessary to extrapolate the cross sections down to either the threshold energy or to 0.01 keV, and to extrapolate up to 20 MeV. We then fit the data to a function so that we can get a smoothed set of interpolated values at up to 321 energy points. The combined data are then processed with the Hiroshima code into flux-weighted, group-averaged cross sections for use with the output from the different physics design codes. We typically use the standard 53 or 175 energy group structures. In a recent companion memo 1 we described the make up of all of the cross-section sets in detail, giving references to both the experimental data and the theoretical calculations that were used. The following sections have the experimental data, in the form of energy-cross section pairs, for the titanium, chromium, bromine, krypton, yttrium, zirconium, iodine, europium, lutetium, and bismuth sets. The other cross-section sets are not directly based on enough experimental data to warrant their listing here. Many of the reactions used in these sets are based on calculated cross sections. In making these calculations certain parameters are sometimes adjusted so that the calculated cross sections match experimental data. In some of these cases we have made a further normalization to give a closer agreement to selected experimental data, and such normalizations are noted in this document. In other cases no further normalization was made. In Table 1 we summarize the reactions for which we present the experimental data given in Tables 2-46. In Figs. 1-35 we show plots of the experimental data together with the actual excitation functions used in the cross-section sets. Some reactions in the current sets are based on

  5. α scattering and α -induced reaction cross sections of 64Zn at low energies

    NASA Astrophysics Data System (ADS)

    Ornelas, A.; Mohr, P.; Gyürky, Gy.; Elekes, Z.; Fülöp, Zs.; Halász, Z.; Kiss, G. G.; Somorjai, E.; Szücs, T.; Takács, M. P.; Galaviz, D.; Güray, R. T.; Korkulu, Z.; Özkan, N.; Yalçın, C.

    2016-11-01

    Background: α -nucleus potentials play an essential role for the calculation of α -induced reaction cross sections at low energies in the statistical model. Uncertainties of these calculations are related to ambiguities in the adjustment of the potential parameters to experimental elastic scattering angular distributions and to the energy dependence of the effective α -nucleus potentials. Purpose: The present work studies the total reaction cross section σreac of α -induced reactions at low energies which can be determined from the elastic scattering angular distribution or from the sum over the cross sections of all open nonelastic channels. Method: Elastic and inelastic 64Zn(α ,α )64Zn angular distributions were measured at two energies around the Coulomb barrier, at 12.1 and 16.1 MeV. Reaction cross sections of the (α ,γ ) , (α ,n ) , and (α ,p ) reactions were measured at the same energies using the activation technique. The contributions of missing nonelastic channels were estimated from statistical model calculations. Results: The total reaction cross sections from elastic scattering and from the sum of the cross sections over all open nonelastic channels agree well within the uncertainties. This finding confirms the consistency of the experimental data. At the higher energy of 16.1 MeV, the predicted significant contribution of compound-inelastic scattering to the total reaction cross section is confirmed experimentally. As a by-product it is found that most recent global α -nucleus potentials are able to describe the reaction cross sections for 64Zn around the Coulomb barrier. Conclusions: Total reaction cross sections of α -induced reactions can be well determined from elastic scattering angular distributions. The present study proves experimentally that the total cross section from elastic scattering is identical to the sum of nonelastic reaction cross sections. Thus, the statistical model can reliably be used to distribute the total reaction

  6. A national cross-sectional study on effects of fluoride-safe water supply on the prevalence of fluorosis in China

    PubMed Central

    Wang, Cheng; Gao, Yanhui; Wang, Wei; Zhao, Lijun; Zhang, Wei; Han, Hepeng; Shi, Yuxia; Yu, Guangqian; Sun, Dianjun

    2012-01-01

    Objective To assess the effects of provided fluoride-safe drinking-water for the prevention and control of endemic fluorosis in China. Design A national cross-sectional study in China. Setting In 1985, randomly selected villages in 27 provinces (or cities and municipalities) in 5 geographic areas all over China. Participants Involved 81 786 children aged from 8 to 12 and 594 698 adults aged over 16. Main outcome measure The prevalence of dental fluorosis and clinical skeletal fluorosis, the fluoride concentrations in the drinking-water in study villages and in the urine of subjects. Results The study showed that in the villages where the drinking-water fluoride concentrations were higher than the government standard of 1.2 mg/l, but no fluoride-safe drinking-water supply scheme was provided (FNB areas), the prevalence rate and index of dental fluorosis in children, and prevalence rate of clinical skeletal fluorosis in adults were all significantly higher than those in the historical endemic fluorosis villages after the fluoride-safe drinking-water were provided (FSB areas). Additionally, the prevalence rate of dental fluorosis as well as clinical skeletal fluorosis, and the concentration of fluoride in urine were found increased with the increase of fluoride concentration in drinking-water, with significant positive correlations in the FNB areas. While, the prevalence rate of dental fluorosis and clinical skeletal fluorosis in different age groups and their degrees of prevalence were significantly lower in the FSB areas than those in the FNB areas. Conclusions The provision of fluoride-safe drinking-water supply schemes had significant effects on the prevention and control of dental fluorosis and skeletal fluorosis. The study also indicated that the dental and skeletal fluorosis is still prevailing in the high-fluoride drinking-water areas in China. PMID:23015601

  7. Effects of Push-ups Plus Sling Exercise on Muscle Activation and Cross-sectional Area of the Multifidus Muscle in Patients with Low Back Pain.

    PubMed

    Kim, Gye-Yeop; Kin, Se-Hun

    2013-12-01

    [Purpose] The purpose of this study was to examine the effect of lumbar stability exercises on chronic low back pain by using sling exercise and push-ups. [Subjects] Thirty adult subjects with chronic back pain participated, with 10 adults being assigned to each of 3 exercise groups: general physical therapy (PT), lumbar stability using sling exercises (Sling Ex), and sling exercise plus push-ups (Sling Ex+PU). Each group trained for 30 minutes 3 times a week for 6 weeks. The Oswestry Disability Index (ODI), surface electromyographic (sEMG) activity of the lumbar muscles, and cross-sectional area of the multifidus muscle on computed tomography (CT) were evaluated before and at 2, 4, and 6 weeks of therapy. [Results] A significant decrease in ODI was seen in all therapy groups, and this change was greater in the Sling Ex and Sling Ex+PU groups than in the PT group. No changes in sEMG activity were noted in the PT group, whereas significant increases in the sEMG activities of all lumbar muscles were found in the other 2 groups. The increases in the sEMG activities of the rectus abdominis and internal and external oblique muscles of the abdomen were greater in the Sling Ex+PU group than in the other 2 groups. [Conclusion] These findings demonstrate that Sling Ex+PU, similar to normal lumbar stabilization exercise, is effective in activating and improving the function of the lumbar muscles. These results suggest that Sling Ex+PU has a positive impact on stabilization of the lumbar region.

  8. Cross-sectional and longitudinal study protocols of the ‘ADIposity and BOne metabolism: effects of eXercise-induced weight loss in obese adolescents’ (ADIBOX) project

    PubMed Central

    Chaplais, Elodie; Naughton, Geraldine; Greene, David; Pereira, Bruno; Thivel, David; Courteix, Daniel

    2016-01-01

    Introduction A need exists for sustainable and clinically effective weight management interventions, suitable for preventing well-linked chronic disease such as diabetes and cardiovascular disease and some less investigated secondary conditions such as bone alteration. The ADIposity and BOne metabolism: effects of eXercise-induced weight loss in obese adolescents (ADIBOX) protocol was designed to provide a better understanding of the interaction between adipokines and bone hormones in adolescents with obesity and how a 10-month physical activity programme may affect these interactions. Methods and analysis The ADIBOX protocol combines 2 studies. The first study involves a total of 68 adolescents aged 12–16 years. This cross-sectional study will include both males and females (1:1 ratio), either living with obesity/overweight (n=34; body mass index (BMI) ≤97th centile and ≥85th centile) or normal weight (n=34; BMI<85th centile). The second study is a longitudinal study that will include 50 obese adolescent girls and track them over a period of 42 weeks. Weight loss programme will consist of a combination of physical activity and a normocaloric diet. Bone and adiposity-related measurements will be performed every 14 weeks. Both studies will assess participants' anthropometric profile, nutrition and physical activity, body composition, bone densitometry and blood markers of bone, growth and adiposity. Ethics and dissemination The ADIBOX protocol complies with the ethics guidelines for clinical research and has been approved by their respective ethics committee (Australian Catholic University Committee Ethic, Australia and Hospital Sud Est 1 committee, France). Findings from this protocol are expected to clarify the possible interactions between adiposity and bone in childhood obesity and will be disseminated at several research conferences and published articles in peer-reviewed journals. Trial registration number NCT02626273; Pre-results. PMID:27797988

  9. Calculation of Cross Sections in Electron-Nuclear Dynamics

    NASA Astrophysics Data System (ADS)

    Cabrera-Trujillo, R.; Sabin, John R.; Deumens, E.; Öhrn, Y.

    In this work, we present an overview of the study of total and differential cross section calculations within the electron-nuclear dynamics (END). END is a method to solve the time-dependent Schrödinger equation in a non-adiabatic approach to direct dynamics. The method takes advantage of a coherent state representation of the molecular wave function. A quantum-mechanical Lagrangian formulation is employed to approximate the Schrödinger equation, via the time-dependent variational principle, to a set of coupled first-order differential equations in time for the END. We obtain the final wave function for the system allowing the determination of collisional properties of interest, as for example, deflection functions, charge exchange probabilities and amplitudes, and differential cross sections. We discuss the use and selection of basis sets for both the electronic description of the colliding systems as well as for their importance in the description of electron capture. As quantum effects are important in many cases and lacking for classical nuclei, we discuss the Schiff methodology and its advantages over other traditional methods for including semiclassical corrections. Time-lapse rendering of the dynamics of the participating electrons and atomic nuclei provides for a detailed view of dynamical and reactive processes. Comparison to experimental and other theoretical results is provided where appropriate data are available.

  10. Measurement of Neutrino Induced Quasi-Elastic Cross Section

    NASA Astrophysics Data System (ADS)

    Kim, Jae

    2006-04-01

    The measurement of the weak mixing angle is the goal, using the data collected in the NOMAD experiment at CERN. Studying the neutrino induced Quasi-Elastic (QE) scattering, in which neutrino hits neutron and results in a muon and a proton, would enhance our understanding of the `higher-twist effect' -- an effect that parameterizes the weak mixing angle. Toward this, I developed a likelihood probability density function that enabled me to eliminate a significant portion of the background, resonance and deep inelastic scattering events. As the Monte Carlo (MC) is only reliable to a precision not better than 15 -- 20 percent, I developed several techniques to make sure that MC and DATA agreed around 5 percent. The axial mass and QE cross section can then be calculated. Techniques and the preliminary results relevant to the calculation will be presented.

  11. 45. Cross Section through the Power House, from Construction Drawing ...

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

    45. Cross Section through the Power House, from Construction Drawing 2042-F-23, entitled General Arrangement of Power Plant, Sections. (Original drawing, in the possession of Wyre Dick and Company, Livingston, New Jersey.) - Central Railroad of New Jersey, Engine Terminal, Jersey City, Hudson County, NJ

  12. 44. Cross section of the Blacksmith Shop from Construction Drawing ...

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

    44. Cross section of the Blacksmith Shop from Construction Drawing 2042-F-15, entitled Machine and Blacksmith Shop; Plan, Elevations, and Sections. (Original drawing, in the possession of Wyre Dick and Company, Livingston, New Jersey.) - Central Railroad of New Jersey, Engine Terminal, Jersey City, Hudson County, NJ

  13. Determining the partial photoionization cross-sections of ethyl radicals.

    PubMed

    FitzPatrick, B L; Maienschein-Cline, M; Butler, L J; Lee, S-H; Lin, J J

    2007-12-13

    Using a crossed laser-molecular beam scattering apparatus, these experiments photodissociate ethyl chloride at 193 nm and detect the Cl and ethyl products, resolved by their center-of-mass recoil velocities, with vacuum ultraviolet photoionization. The data determine the relative partial cross-sections for the photoionization of ethyl radicals to form C2H5+, C2H4+, and C2H3+ at 12.1 and 13.8 eV. The data also determine the internal energy distribution of the ethyl radical prior to photoionization, so we can assess the internal energy dependence of the photoionization cross-sections. The results show that the C2H4++H and C2H3++H2 dissociative photoionization cross-sections strongly depend on the photoionization energy. Calibrating the ethyl radical partial photoionization cross-sections relative to the bandwidth-averaged photoionization cross-section of Cl atoms near 13.8 eV allows us to use these data in conjunction with literature estimates of the Cl atom photoionization cross-sections to put the present bandwidth-averaged cross-sections on an absolute scale. The resulting bandwidth-averaged cross-section for the photoionization of ethyl radicals to C2H5+ near 13.8 eV is 8+/-2 Mb. Comparison of our 12.1 eV data with high-resolution ethyl radical photoionization spectra allows us to roughly put the high-resolution spectrum on the same absolute scale. Thus, one obtains the photoionization cross-section of ethyl radicals to C2H5+ from threshold to 12.1 eV. The data show that the onset of the C2H4++H dissociative photoionization channel is above 12.1 eV; this result offers a simple way to determine whether the signal observed in photoionization experiments on complex mixtures is due to ethyl radicals. We discuss an application of the results for resolving the product branching in the O+allyl bimolecular reaction.

  14. Measurement of the 242Pu neutron capture cross section

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  15. The Effects of the Habitual Consumption of Miso Soup on the Blood Pressure and Heart Rate of Japanese Adults: A Cross-sectional Study of a Health Examination

    PubMed Central

    Ito, Koji; Miyata, Kenji; Mohri, Masahiro; Origuchi, Hideki; Yamamoto, Hideo

    2017-01-01

    Objective It is recommended that middle-aged and elderly individuals reduce their salt intake because of the high prevalence of hypertension. The consumption of miso soup is associated with salt intake, and the reduced consumption of miso soup has been recommended. Recent studies have demonstrated that the consumption of miso soup can attenuate an autonomic imbalance in animal models. However, it is unclear whether these results are applicable to humans. This study examined the cross-sectional association between the frequency of miso soup consumption and the blood pressure and heart rate of human subjects. Methods A total of 527 subjects of 50 to 81 years of age who participated in our hospital health examination were enrolled in the present study and divided into four groups based on the frequency of their miso soup consumption ([bowl(s) of miso soup/week] Group 1, <1; Group2, <4; Group3, <7; Group4, ≥7). The blood pressure levels and heart rates of the subjects in each group were compared. Furthermore, a multivariable analysis was performed to determine whether miso soup consumption was an independent factor affecting the incidence of hypertension or the heart rate. Results The frequency of miso soup consumption was not associated with blood pressure. The heart rate was, however, lower in the participants who reported a high frequency of miso soup consumption. A multivariable analysis revealed that the participants who reported a high frequency of miso soup consumption were more likely to have a lower heart rate, but that the consumption of miso soup was not associated with the incidence of hypertension. Conclusion These results indicate that miso soup consumption might decrease the heart rate, but not have a significant effect on the blood pressure of in middle-aged and elderly Japanese individuals. PMID:28049996

  16. Cohabitational effect of grandparents on dietary intake among young Japanese women and their mothers living together. A multicenter cross-sectional study.

    PubMed

    Kobayashi, Satomi; Asakura, Keiko; Suga, Hitomi; Sasaki, Satoshi

    2015-08-01

    We examined the cohabitational effect of the grandparents on dietary intakes among young Japanese women and their mothers, using data from a cross-sectional multicenter study conducted in 35 of 47 prefectures in Japan. Among a total of 2032 three-generation families, 1336 female dietetic students (18-20 years), 1336 of their mothers (36-59 years), and 1560 of their paternal or maternal grandmothers (59-94 years) were included. Intake of foods and nutrients was assessed with self-administered diet history questionnaires. The prevalence of students and their mothers living with the grandparents (GP) was 36%. Students living with GP had a higher intake of fruits, vegetables, total dietary fiber, β-carotene, vitamin C and potassium and lower intake of meats than those living without GP. For mothers, fish and shellfish and vitamin C intakes were higher and meat intake was lower among participants living with GP. The median correlation coefficients of food and nutrient intakes in the students-grandmothers living together was higher than in those living apart for both paternal grandmothers (PGM) and maternal grandmothers (MGM) (all P <0.01). The median values of mothers-PGM living together were also significantly higher than in those living apart (P <0.01). However, the values of mothers-MGM did not significantly differ between those living with and without MGM. These results may suggest that family members who live together tend to share similar dietary habits. Further, the mother's dietary habits might affect those of their children even after they live apart.

  17. Comparative genotoxic and cytotoxic effects of the oral antidiabetic drugs sitagliptin, rosiglitazone, and pioglitazone in patients with type-2 diabetes: a cross-sectional, observational pilot study.

    PubMed

    Oz Gul, Ozen; Cinkilic, Nilufer; Gul, Cuma Bulent; Cander, Soner; Vatan, Ozgur; Ersoy, Canan; Yılmaz, Dilek; Tuncel, Ercan

    2013-09-18

    This cross-sectional, observational pilot study was designed to investigate the frequency of different endpoints of genotoxicity (sister-chromatid exchange, total chromosome aberrations, and micronucleus formation) and cytotoxicity (mitotic index, replication index, and nuclear division index) in the peripheral lymphocytes of patients with type-2 diabetes treated with different oral anti-diabetic agents for 6 months. A total of 104 patients who met the American Diabetes Association criteria for type-2 diabetes were enrolled in the study. Of the 104 patients, 33 were being treated with sitagliptin (100mg/day), 25 with pioglitazone (30mg/day), 22 with rosiglitazone (4mg/day), and 24 with medical nutrition therapy (control group). The results for all the genotoxicity endpoints were significantly different across the four study groups. Post hoc analysis revealed that the genotoxicity observed in the sitagliptin group was significantly higher than that observed in the medical nutrition therapy group, but lower than that occurring in subjects who received thiazolidinediones. All of the three cytotoxicity endpoints were significantly lower in patients treated by oral anti-diabetic agents compared with those who received medical nutrition therapy. However, the three indexes did not differ significantly in the sitagliptin, rosiglitazone, and pioglitazone groups. Taken together, these pilot data indicate that sitagliptin and thiazolidinediones may exert genotoxic and cytotoxic effects in patients with type-2 diabetes. Further investigations are necessary to clarify the possible long-term differences between oral anti-diabetic drugs in terms of genotoxicity and cytotoxicity, and how these can modulate the risk of developing diabetic complications in general and cancer in particular.

  18. Effects of cigarette smoking on early arthritis: a cross-sectional study-data from the Argentine Consortium for Early Arthritis (CONAART).

    PubMed

    Haye Salinas, María Jezabel; Retamozo, Soledad; Alvarez, Ana Cecilia; Maldonado Ficco, Hernán; Dal Pra, Fernando; Citera, Gustavo; Benegas, Mariana; Chaparro del Moral, Rafael; Rillo, Oscar; Secco, Anastasia; Marino Claverie, Lucila; Catalan Pellet, Antonio; Marcos, Josefina; García, Mercedes Argentina; Marcos, Juan Carlos; Barbaglia, Ana; Bellomio, Verónica; Berman, Alberto; Quiroz, Cristian; Soriano, Enrique R; Ceccato, Federico; Paira, Sergio; Vazquez, Doralia; Juarez, Vicente Ricardo; Velozo, Edson Javier; Salvatierra, Gabriela; Caeiro, Francisco

    2015-05-01

    Our objective was to analyze the effects of cigarette smoking on disease activity, functional capacity, radiographic damage, serology and presence of extraarticular manifestations in patients with rheumatoid arthritis and undifferentiated arthritis. This is a cross-sectional study of 1,305 patients (729 with rheumatoid arthritis and 576 with undifferentiated arthritis) from CONAART, the Argentine Consortium for Early Arthritis that includes patients older than 16 years with <2 years of disease. Sociodemographic data, clinical characteristics of the disease and smoking history were collected. In patients with rheumatoid arthritis the disease activity score of 28 joints was 5.4 ± 1.3 in current smokers, 5.2 ± 1.4 in former smokers and 5.1 ± 1.4 in never smokers (p = 0.011). The simple erosion narrowing score was higher in current smokers and former smokers than in never smokers (M 14.0, R Q 6.0-21.0; M 15.0, R Q 7.0-24.0; M 10.0, R Q 5.0-17.0; p = 0.006). Current smokers had higher rheumatoid factor titer (M 160.0, R Q 80.0-341.0) than former smokers (M 146.8, R Q 6.03-255.5) and never smokers (M 15.0, R Q 9.0-80.0) (p = 0.004). The variable independently associated with tobacco exposure was simple erosion narrowing score (OR = 1.03, 95 % CI 1.00-1.05; p = 0.012). In patients with undifferentiated arthritis, an association between smoking status and parameters of activity or radiographic damage was not observed. Neither was tobacco exposure related to the presence of extraarticular manifestations or to the degree of disability in any of the two groups of patients. No relation was found between disease activity and severity, and number of packs smoked per year. Tobacco.

  19. The Effects of the Habitual Consumption of Miso Soup on the Blood Pressure and Heart Rate of Japanese Adults: A Cross-sectional Study of a Health Examination.

    PubMed

    Ito, Koji; Miyata, Kenji; Mohri, Masahiro; Origuchi, Hideki; Yamamoto, Hideo

    Objective It is recommended that middle-aged and elderly individuals reduce their salt intake because of the high prevalence of hypertension. The consumption of miso soup is associated with salt intake, and the reduced consumption of miso soup has been recommended. Recent studies have demonstrated that the consumption of miso soup can attenuate an autonomic imbalance in animal models. However, it is unclear whether these results are applicable to humans. This study examined the cross-sectional association between the frequency of miso soup consumption and the blood pressure and heart rate of human subjects. Methods A total of 527 subjects of 50 to 81 years of age who participated in our hospital health examination were enrolled in the present study and divided into four groups based on the frequency of their miso soup consumption ([bowl(s) of miso soup/week] Group 1, <1; Group2, <4; Group3, <7; Group4, ≥7). The blood pressure levels and heart rates of the subjects in each group were compared. Furthermore, a multivariable analysis was performed to determine whether miso soup consumption was an independent factor affecting the incidence of hypertension or the heart rate. Results The frequency of miso soup consumption was not associated with blood pressure. The heart rate was, however, lower in the participants who reported a high frequency of miso soup consumption. A multivariable analysis revealed that the participants who reported a high frequency of miso soup consumption were more likely to have a lower heart rate, but that the consumption of miso soup was not associated with the incidence of hypertension. Conclusion These results indicate that miso soup consumption might decrease the heart rate, but not have a significant effect on the blood pressure of in middle-aged and elderly Japanese individuals.

  20. Effects of drift gas on collision cross sections of a protein standard in linear drift tube and traveling wave ion mobility mass spectrometry.

    PubMed

    Jurneczko, Ewa; Kalapothakis, Jason; Campuzano, Iain D G; Morris, Michael; Barran, Perdita E

    2012-10-16

    There has been a significant increase in the use of ion mobility mass spectrometry (IM-MS) to investigate conformations of proteins and protein complexes following electrospray ionization. Investigations which employ traveling wave ion mobility mass spectrometry (TW IM-MS) instrumentation rely on the use of calibrants to convert the arrival times of ions to collision cross sections (CCS) providing "hard numbers" of use to structural biology. It is common to use nitrogen as the buffer gas in TW IM-MS instruments and to calibrate by extrapolating from CCS measured in helium via drift tube (DT) IM-MS. In this work, both DT and TW IM-MS instruments are used to investigate the effects of different drift gases (helium, neon, nitrogen, and argon) on the transport of multiply charged ions of the protein myoglobin, frequently used as a standard in TW IM-MS studies. Irrespective of the drift gas used, recorded mass spectra are found to be highly similar. In contrast, the recorded arrival time distributions and the derived CCS differ greatly. At low charge states (7 ≤ z ≤ 11) where the protein is compact, the CCS scale with the polarizability of the gas; this is also the case for higher charge states (12 ≤ z ≤ 22) where the protein is more unfolded for the heavy gases (neon, argon, and nitrogen) but not the case for helium. This is here interpreted as a different conformational landscape being sampled by the lighter gas and potentially attributable to increased field heating by helium. Under nanoelectrospray ionization (nESI) conditions, where myoglobin is sprayed from an aqueous solution buffered to pH 6.8 with 20 mM ammonium acetate, in the DT IM-MS instrument, each buffer gas can yield a different arrival time distribution (ATD) for any given charge state.

  1. Pattern of chemotherapy-related adverse effects among adult cancer patients treated at Gondar University Referral Hospital, Ethiopia: a cross-sectional study

    PubMed Central

    Belachew, Sewunet Admasu; Erku, Daniel Asfaw; Mekuria, Abebe Basazn; Gebresillassie, Begashaw Melaku

    2016-01-01

    Background Adverse drug reactions (ADRs) are a global problem and constitute a major clinical problem in terms of human suffering. The high toxicity and narrow therapeutic index of chemotherapeutic agents makes oncology pharmacovigilance essential. The objective of the present study was to assess the pattern of ADRs occurring in cancer patients treated with chemotherapy in a tertiary care teaching hospital in Ethiopia. Methods A cross-sectional study over a 2-year period from September 2013 to August 2015 was conducted on cancer patients undergoing chemotherapy at Gondar University Referral Hospital Oncology Center. Data were collected directly from patients and their medical case files. The reported ADRs were assessed for causality using the World Health Organization’s causality assessment scale and Naranjo’s algorithm. The severities of the reported reactions were also assessed using National Cancer Institute Common Terminology CTCAE version 4.0. The Pear-son’s chi-square test was employed to examine the association between two categorical variables. Results A total of 815 ADRs were identified per 203 patients included in the study. The most commonly occurring ADRs were nausea and vomiting (18.9%), infections (16.7%), neutropenia (14.7%), fever and/or chills (11.3%), and anemia (9.3%). Platinum compounds (31.4%) were the most common group of drugs causing ADRs. Of the reported ADRs, 65.8% were grades 3–4 (severe level), 29.9% were grades 1–2 (mild level), and 4.3% were grade 5 (toxic level). Significant association was found between age, number of chemotherapeutic agents, as well as dose of chemotherapy with the occurrence of grades 3–5 toxicity. Conclusion The high incidence of chemotherapy-related ADRs among cancer patients is of concern. Setting up an effective ADR monitoring and reporting system (onco-pharmacovigilance) and creating awareness among health care professionals regarding the importance of ADR reporting may help prevent the problem

  2. Respective and Combined Effects of Impairments in Sensorimotor Systems and Cognition on Gait Performance: A Population-Based Cross-Sectional Study

    PubMed Central

    Beauchet, Olivier; Launay, Cyrille P.; Fantino, Bruno; Allali, Gilles; Annweiler, Cédric

    2015-01-01

    Background Respective and combined effects of impairments in sensorimotor systems and cognition on gait performance have not been fully studied. This study aims to describe the respective effects of impairments in muscle strength, distance vision, lower-limb proprioception and cognition on the Timed Up & Go (TUG) scores (i.e., performed TUG [pTUG], imagined TUG [iTUG] and the time difference between these two tests [delta TUG]) in older community-dwellers; and to examine their combined effects on TUG scores. Methods Based on a cross-sectional design, 1792 community-dwellers (70.2±4.8 years; 53.6% female) were recruited. Gait performance was assessed using pTUG, iTUG and delta TUG. Participants were divided into healthy individuals and 15 subgroups of individuals according to the presence of impairment in one or more subsystems involved in gait control (i.e., muscle strength and/or distance vision and/or lower-limb proprioception and/or cognition [episodic memory and executive performance]). Impairment in muscle strength, distance vision and lower-limb proprioception was defined as being in the lowest tertile of performance. Impairment in cognition was defined as abnormal episodic memory and executive tests. Results A total of 191 (10.7%) exhibited impairment in muscle strength, 188 (10.5%) in distance vision, 302 (16.9%) in lower-limb proprioception, and 42 (2.3%) in cognition. Linear regressions showed that cognitive impairment as well as dual combinations of impairments were associated with increased pTUG (P<0.02). Impairment in lower-limb proprioception was associated with decreased iTUG (P=0.015). All combinations of impairments, except those including muscle strength and the combinations of the 4 subsystems, were associated with increased delta TUG (P<0.04). Conclusion Cognitive integrity is central for efficient gait control and stability, whereas lower-limb proprioception seems to be central for gait imagery. PMID:25992567

  3. Complexity-Based Measures Inform Effects of Tai Chi Training on Standing Postural Control: Cross-Sectional and Randomized Trial Studies

    PubMed Central

    Wayne, Peter M.; Gow, Brian J.; Costa, Madalena D.; Peng, C.-K.; Lipsitz, Lewis A.; Hausdorff, Jeffrey M.; Davis, Roger B.; Walsh, Jacquelyn N.; Lough, Matthew; Novak, Vera; Yeh, Gloria Y.; Ahn, Andrew C.; Macklin, Eric A.; Manor, Brad

    2014-01-01

    Background Diminished control of standing balance, traditionally indicated by greater postural sway magnitude and speed, is associated with falls in older adults. Tai Chi (TC) is a multisystem intervention that reduces fall risk, yet its impact on sway measures vary considerably. We hypothesized that TC improves the integrated function of multiple control systems influencing balance, quantifiable by the multi-scale “complexity” of postural sway fluctuations. Objectives To evaluate both traditional and complexity-based measures of sway to characterize the short- and potential long-term effects of TC training on postural control and the relationships between sway measures and physical function in healthy older adults. Methods A cross-sectional comparison of standing postural sway in healthy TC-naïve and TC-expert (24.5±12 yrs experience) adults. TC-naïve participants then completed a 6-month, two-arm, wait-list randomized clinical trial of TC training. Postural sway was assessed before and after the training during standing on a force-plate with eyes-open (EO) and eyes-closed (EC). Anterior-posterior (AP) and medio-lateral (ML) sway speed, magnitude, and complexity (quantified by multiscale entropy) were calculated. Single-legged standing time and Timed-Up–and-Go tests characterized physical function. Results At baseline, compared to TC-naïve adults (n = 60, age 64.5±7.5 yrs), TC-experts (n = 27, age 62.8±7.5 yrs) exhibited greater complexity of sway in the AP EC (P = 0.023), ML EO (P<0.001), and ML EC (P<0.001) conditions. Traditional measures of sway speed and magnitude were not significantly lower among TC-experts. Intention-to-treat analyses indicated no significant effects of short-term TC training; however, increases in AP EC and ML EC complexity amongst those randomized to TC were positively correlated with practice hours (P = 0.044, P = 0.018). Long- and short-term TC training were positively associated with physical function

  4. Cross-sectional study on respiratory effect of toner-exposed work in manufacturing plants, Japan: pulmonary function, blood cells, and biochemical markers.

    PubMed

    Kitamura, H; Terunuma, N; Kurosaki, S; Hata, K; Ide, R; Kuga, H; Kakiuchi, N; Masuda, M; Totsuzaki, T; Osato, A; Uchino, B; Kitahara, K; Iwasaki, A; Yoshizumi, K; Morimoto, Y; Kasai, H; Murase, T; Higashi, T

    2009-06-01

    The aim of the study is to examine the relationship between toner-exposed work and health indices related to respiratory disorders and to confirm the baseline of a cohort study to clarify the effect of toner exposure in manufacturing plants. Subjects were 1614 male workers (809 toner-exposed workers and 805 referents) who were engaged in toner manufacturing plants in Japan (Fuji Xerox Co., Ltd). The age of subjects was from 19 to 59 years, and the average age was 40.2 years(median 40 years, SD 7.67). We conducted a pulmonary function test (PEFR, VC, FVC, FEV(1.0)%, V25/Ht) and a blood cell test (RBC, Hb, Hct, Plt, WBC, cell contents of WBC) and measured biochemical indices in blood (ALT, AST, gamma-GTP, CRP, IgE) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in urine. Student t-test and logistic regression analysis were applied to compare between the toner-exposed workers and the referents and to analyze the relationship among indices of effects and independent factors. There was no significant difference between the two groups in blood cell count and biochemical indices. Inflammation- and allergy-related markers such as 8OHdG and IgE also showed no significant difference between toner-exposed workers and the referents. The influence of smoking on pulmonary function indices was observed, but there was no relationship between the pulmonary function and toner-exposed work. In this article, we report a preliminary cross-sectional analysis in the subjects of a cohort study. No difference in pulmonary function indices was observed between the toner-exposed workers and the referents, and there was no consistent relationship between the exposure status and examined indices; however, the prevalence of subjective respiratory symptoms was higher in the exposed workers as presented in another report. Further analysis is important in the ongoing cohort study to clarify the effect of toner exposure on respiratory systems.

  5. An evaluation of wind turbine blade cross section analysis techniques.

    SciTech Connect

    Paquette, Joshua A.; Griffith, Daniel Todd; Laird, Daniel L.; Resor, Brian Ray

    2010-03-01

    The blades of a modern wind turbine are critical components central to capturing and transmitting most of the load experienced by the system. They are complex structural items composed of many layers of fiber and resin composite material and typically, one or more shear webs. Large turbine blades being developed today are beyond the point of effective trial-and-error design of the past and design for reliability is always extremely important. Section analysis tools are used to reduce the three-dimensional continuum blade structure to a simpler beam representation for use in system response calculations to support full system design and certification. One model simplification approach is to analyze the two-dimensional blade cross sections to determine the properties for the beam. Another technique is to determine beam properties using static deflections of a full three-dimensional finite element model of a blade. This paper provides insight into discrepancies observed in outputs from each approach. Simple two-dimensional geometries and three-dimensional blade models are analyzed in this investigation. Finally, a subset of computational and experimental section properties for a full turbine blade are compared.

  6. Fast Neutron Inelastic Scattering Cross Sections in THORIUM-232.

    NASA Astrophysics Data System (ADS)

    Ciarcia, Christopher Albert

    Fast neutron inelastic scattering cross sections for levels between 700-1550-keV excitation energy in the actinide nucleus, ('232)Th, have been measured using the (n,n') time-of-flight technique. Two series of measurements were undertaken using neutrons with a typical energy spread of 8-10 keV, generated by the ('7)Li(p,n)('7)Be reaction. These measurments for 125(DEGREES)-differential scattering cross sections were performed over the incident neutron energy regions of (i) 0.950-1.550 MeV, in 50-keV intervals with the time-of-flight spectrometer optimized to detect 0.200 -0.400-MeV scattered neutrons and (ii) 1.200-2.000 MeV, in 100-keV intervals with the time-of-flight spectrometer optimized to detect 0.400-0.800-MeV scattered neutrons. Over these scattered energy regions, an overall energy resolution of less than 15 keV was maintained. The relative neutron fluence was determined for each individual measurement, by positioning the main detector at 0(DEGREES) to view the primary neutron flux. Relative normalization was achieved by measuring the direct neutron flux from the lithium target with a fixed overhead monitor detector in both measurements. Main detector response was determined by comparison with a ('235)U fission chamber of known efficiency. Techniques for unfolding the complicated spectra obtained from these (n,n') studies were developed, employing user interactive computer codes to (i) generate simulated scattered neutron group response functions, (ii) subtract background effects from the measured spectra, (iii) approximate the background subtracted spectra in a weighted least-squares fashion by a superposition of response functions and (iv) make corrections for neutron absorption, finite scatterer size effects and multiple neutron scattering. Support codes consisting of graphics interaction packages, data file manipulation and transfer utility routines were created to assist in the spectral analysis procedure. Excitation function and angular distribution

  7. Electromagnetic Dissociation Cross Sections using Weisskopf-Ewing Theory

    NASA Technical Reports Server (NTRS)

    Adamczyk, Anne M.; Norbury, John W.

    2011-01-01

    It is important that accurate estimates of crew exposure to radiation are obtained for future long-term space missions. Presently, several space radiation transport codes exist to predict the radiation environment, all of which take as input particle interaction cross sections that describe the nuclear interactions between the particles and the shielding material. The space radiation transport code HZETRN uses the nuclear fragmentation model NUCFRG2 to calculate Electromagnetic Dissociation (EMD) cross sections. Currently, NUCFRG2 employs energy independent branching ratios to calculate these cross sections. Using Weisskopf-Ewing (WE) theory to calculate branching ratios, however, is more advantageous than the method currently employed in NUCFRG2. The WE theory can calculate not only neutron and proton emission, as in the energy independent branching ratio formalism used in NUCFRG2, but also deuteron, triton, helion, and alpha particle emission. These particles can contribute significantly to total exposure estimates. In this work, photonuclear cross sections are calculated using WE theory and the energy independent branching ratios used in NUCFRG2 and then compared to experimental data. It is found that the WE theory gives comparable, but mainly better agreement with data than the energy independent branching ratio. Furthermore, EMD cross sections for single neutron, proton, and alpha particle removal are calculated using WE theory and an energy independent branching ratio used in NUCFRG2 and compared to experimental data.

  8. Experience With the SCALE Criticality Safety Cross Section Libraries

    SciTech Connect

    Bowman, S.M.

    2000-08-21

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

  9. Electron Impact Ionization Cross Sections in Rb and Cs.

    NASA Astrophysics Data System (ADS)

    Reddish, T. J.; Lukomski, M.; Sutton, S.; Kedzierski, W.; McConkey, J. W.; Bartschat, K.; Bartlett, P. L.; Stelbovics, A. T.; Bray, I.

    2006-05-01

    We present a new atom trapping technique for determining absolute, total ionisation cross sections (TICS) out of an excited atom. The novel feature of this method is in utilizing Doppler cooling of neutral atoms to determine ionisation cross sections. This fluorescence-monitoring experiment, which is a variant of the `trap loss' technique, has enabled us to obtain the experimental electron impact ionisation cross sections out of the Cs 6^2P3/2 excited state between 7 - 400 eV. New CCC, R-Matrix with Pseudo-States (RMPS), and Born approximation single ionisation cross sections (SICS) are also presented for both the ground and excited states of Cs and Rb, and compared with the available experimental data. The comparison of the results reveals the importance of the autoionisation and multiple ionisation contributions to the TICS. The autoionisation contribution appears to be substantial for ionisation out of the Cs 6^2P and Rb 5^2P excited states; ˜ 3-4 larger than the direct ionisation contribution predicted by CCC at ˜ 30-50 eV. This surprising result shows the importance of multi-electron processes in determining the ionisation cross sections of heavy alkali atoms.

  10. Progress on FP13 Total Cross Section Measurements Capability

    SciTech Connect

    Ullmann, John Leonard; Couture, Aaron Joseph; Koehler, Paul E.; Mocko, Michal; Mosby, Shea Morgan; Wender, Stephen Arthur

    2016-09-26

    An accurate knowledge of the neutron capture cross section is important for many applications. Experimental measurements are important since theoretical calculations of capture have been notoriously difficult, with the ratio of measured to calculated cross sections often a factor of 2 or more in the 10 keV to 1 MeV region. However, a direct measurement of capture cannot be made on many interesting radioactive nuclides because of their short half-life or backgrounds caused by their nuclear decay. On the other hand, neutron transmission measurements of the total cross section are feasible for a wide range of radioactive nuclides since the detectors are far from the sample, and often are less sensitive to decay radiation. The parameters extracted from a total cross section measurement, which include the average resonance spacing, the neutron strength function, and the average total radiation width, (Γγ), provide tight constraints on the calculation of the capture cross section, and when applied produce much more accurate results. These measurements can be made using the intense epithermal neutron flux at the Lujan Center on relatively small quantities of target material. It was the purpose of this project to investigate and develop the capability to make these measurements. A great deal of progress was made towards establishing this capability during 2016, including setting up the flight path and obtaining preliminary results, but more work remains to be done.

  11. Characterization of radar cross section of carbon fiber composite materials

    NASA Astrophysics Data System (ADS)

    Riley, Elliot J.; Lenzing, Erik H.; Narayanan, Ram M.

    2015-05-01

    Carbon fiber composite (CFC) materials have been used for many structural applications for decades. Their electromagnetic properties are also of great interest and are being quantified by recent research. This research explores shielding effectiveness, antenna design, conductivity, reflection, and absorption properties. The work in this paper specifically characterizes the radar cross section (RCS) of CFC structures. Various CFC planar samples were created using a wet layup method and vacuum bagging techniques. These samples were then placed in an anechoic chamber and their RCS values were measured at normal incidence. These measured values were compared to those of aluminum samples made into the same shape as the CFC samples. All of the measurements were made over 7 - 12 GHz frequency range. The RCS of the CFC samples show some interesting results. The fiber direction in the CFC samples had great influence on the RCS. Theories and reasoning for the results are presented and discussed.

  12. Effect of cross sectional geometry on PDMS micro peristaltic pump performance: comparison of SU-8 replica molding vs. micro injection molding.

    PubMed

    Graf, Neil J; Bowser, Michael T

    2013-10-07

    Two different fabrication methods were employed to fabricate micropumps with different cross-sectional channel geometries. The first was to fabricate rectangular cross-sectional microchannel geometries using the well known fabrication method of replica molding (REM). The second, and far less utilized fabrication technique, was to create microchannel molds using an in-house fabricated handheld micro injection molding apparatus. The injection mold apparatus was designed for use with elastomeric room temperature vulcanization (RTV) polymers, as opposed to most other injection molding machines, which are designed for use with thermoplastic polymers. The injection mold's bottom plate was used as a microchannel molding template. The molding template was created by threading a small-diameter wire (150 μm or less) through the injection mold's bottom plate, with subsequent adhesion and smoothing of a thin piece of aluminum foil over the wire-raised injection mold template. When molded against, the template produced a rounded/Gaussian-shaped PDMS microchannel. The design of the injection mold will be presented, along with a direct comparison for micropump performance metrics such as flow rate, valving characteristics, and maximum backpressures attainable for each of the respective micropump channel geometries.

  13. Effect of Cross Sectional Geometry on PDMS Micro Peristaltic Pump Performance: Comparison of SU-8 Replica Molding vs. Micro Injection Molding

    PubMed Central

    Graf, Neil J.

    2013-01-01

    Two different fabrication methods were employed to fabricate micropumps with different cross-sectional channel geometries. The first was to fabricate rectangular cross-sectional microchannel geometries using the well known fabrication method of replica molding (REM).1 The second, and far less utilized fabrication technique, was to create microchannel molds using an in-house fabricated handheld micro injection molding apparatus. The injection mold apparatus was designed for use with elastomeric room temperature vulcanization (RTV) polymers, as opposed to most other injection molding machines, which are designed for use with thermoplastic polymers. The injection mold’s bottom plate was used as a microchannel molding template. The molding template was created by threading a small-diameter wire (150 μm or less) through the injection mold’s bottom plate, with subsequent adhesion and smoothing of a thin piece of aluminum foil over the wire-raised injection mold template. When molded against, the template produced a rounded/Gaussian-shaped PDMS microchannel. The design of the injection mold will be presented, along with a direct comparison for micropump performance metrics such as flow rate, valving characteristics, and maximum backpressures attainable for each of the respective micropump channel geometries. PMID:23917263

  14. Inelastic cross sections for positron scattering from atomic hydrogen

    SciTech Connect

    Weber, M.; Hofmann, A.; Raith, W.; Sperber, W.; Jacobsen, F.; Lynn, K.G.

    1994-12-31

    Positronium formation (Ps) cross sections for positrons impinging on atomic hydrogen were measured in the impact energy range from 13eV to 255eV at the High Intensity Positron (HIP) beam at Brookhaven National Laboratory (BNL). The Ps-formation cross section was found to rise rapidly from the threshold at 6.8eV to a maximum value of (2.98 {plus_minus} 0.18) {times} 10{sup {minus}16} cm{sup 2} for {approx} 15eV positrons. By 75eV it drops below the detection limit of 0.17 {times} 10{sup {minus}16} cm{sup 2} which is the present level of statistical uncertainty. The experiment was modified to enable the measurement of doubly differential scattering cross sections.

  15. Pion Total Cross Section in Nucleon - Nucleon Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    2009-01-01

    Total cross section parameterizations for neutral and charged pion production in nucleon - nucleon collisions are compared to experimental data over the projectile momentum range from threshold to 300 GeV. Both proton - proton and proton - neutron reactions are considered. Overall excellent agreement between parameterizations and experiment is found, except for notable disagreements near threshold. In addition, the hypothesis that the neutral pion production cross section can be obtained from the average charged pion cross section is checked. The theoretical formulas presented in the paper obey this hypothesis for projectile momenta below 500 GeV. The results presented provide a test of engineering tools used to calculate the pion component of space radiation.

  16. Cross section versus time delay and trapping probability

    NASA Astrophysics Data System (ADS)

    Luna-Acosta, G. A.; Fernández-Marín, A. A.; Méndez-Bermúdez, J. A.; Poli, Charles

    2016-07-01

    We study the behavior of the s-wave partial cross section σ (k), the Wigner-Smith time delay τ (k), and the trapping probability P (k) as function of the wave number k. The s-wave central square well is used for concreteness, simplicity, and to elucidate the controversy whether it shows true resonances. It is shown that, except for very sharp structures, the resonance part of the cross section, the trapping probability, and the time delay, reach their local maxima at different values of k. We show numerically that τ (k) > 0 at its local maxima, occurring just before the resonant part of the cross section reaches its local maxima. These results are discussed in the light of the standard definition of resonance.

  17. Accurate universal parameterization of absorption cross sections III - light systems

    NASA Astrophysics Data System (ADS)

    Tripathi, R. K.; Cucinotta, F. A.; Wilson, J. W.

    1999-09-01

    Our prior nuclear absorption cross sections model [R.K. Tripathi, F.A. Cucinotta, J.W. Wilson, Nucl. Instr. and Meth. B 117 (1996) 347; R.K. Tripathi, J.W. Wilson, F.A. Cucinotta, Nucl. Instr. and Meth. B 129 (1997) 11] is extended for light systems ( A ⩽ 4) where either both projectile and target are light particles or one is light particle and the other is medium or heavy nucleus. The agreement with experiment is excellent for these cases as well. Present work in combination with our original model provides a comprehensive picture of absorption cross sections for light, medium and heavy systems. As a result the extended model can reliably be used in all studies where there is a need for absorption cross sections.

  18. Photoabsorption cross section of acetylene in the EUV region

    NASA Technical Reports Server (NTRS)

    Wu, C. Y. R.; Judge, D. L.

    1985-01-01

    The measurement of the absolute photoabsorption cross sections of C2H2 in the 175-740 A region by means of a double ionization chamber is reported. The continuum background source is the synchrotron radiation emitted by the Wisconsin 240 MeV electron storage ring. It is found that the cross sections range from 2 to a maximum of 36 Mb. Two new Rydberg series are identified and the cross section data are applied in the analysis of various sum rules. From the rules, it is shown that the data of C2H2 in the 580-1088 A range may be too low, while the measured ionization transition moment may be too high.

  19. Pion photoproduction cross section at large momentum transfer

    SciTech Connect

    Sjoegren, Johan

    2015-02-27

    The Real Compton Scattering experiment was performed in Hall A at the Thomas Jefferson National Accelerator Facility. It was designed to measure, for Compton scattering and π0-photoproduction, the differential cross section over a range of kinematic points and the polarisation transfer to the proton at a single kinematic point. The full range of the experiment in Mandelstam variables t and s was 1.6-6.46 GeV2 and 4.82-10.92 GeV2 respectively with beam energies of 2-6 GeV. The motivation for the experiment is to test the cross section and polarisation transfer predictions of perturbative QCD versus that of predictions from Generalised Parton Distribution models. This thesis will give an overview of the pertinent theory, experimental setup in Hall A and the extracting of the π0-photoproduction cross section.

  20. New Resonance Parameter Evaluation of Cl Neutron Cross Sections

    SciTech Connect

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

    2005-05-24

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

  1. Absorption Cross-Sections of Sodium Diatomic Molecules

    NASA Technical Reports Server (NTRS)

    Fong, Zeng-Shevan

    1985-01-01

    The absorption cross sections of sodium dimers were studied using a heat pipe over operating in the non-heat-pipe mode. Three wavelength regions were observed. They are in the red, the green-blue, and the near ultraviolet regions. The absorption cross section depends on the wavelength of the incident light. Representative peak values for the v"=0 progression in the red and green-blue regions are 2.59 A sup 2 (average value) and 11.77 A sup 2 (T sub ave=624 K). The value for the C greater than X transitions is several tenths A sup 2. The cross sections were measured from absorption spectra taken as a function of temperature.

  2. Reaction cross sections of the deformed halo nucleus 31Ne

    NASA Astrophysics Data System (ADS)

    Urata, Y.; Hagino, K.; Sagawa, H.

    2012-10-01

    Using the Glauber theory, we calculate reaction cross sections for the deformed halo nucleus 31Ne. To this end, we assume that the 31Ne nucleus takes the 30Ne+n structure. To take into account the rotational excitation of the core nucleus 30Ne, we employ the particle-rotor model (PRM). We compare the results to those in the adiabatic limit of PRM, that is, the Nilsson model, and show that the Nilsson model works reasonably well for the reaction cross sections of 31Ne. We also investigate the dependence of the reaction cross sections on the ground-state properties of 31Ne, such as the deformation parameter and the p-wave component in the ground-state wave function.

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

    SciTech Connect

    Schulte, Elaine

    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

  4. 63Ni (n ,γ ) cross sections measured with DANCE

    NASA Astrophysics Data System (ADS)

    Weigand, M.; Bredeweg, T. A.; Couture, A.; Göbel, K.; Heftrich, T.; Jandel, M.; Käppeler, F.; Lederer, C.; Kivel, N.; Korschinek, G.; Krtička, M.; O'Donnell, J. M.; Ostermöller, J.; Plag, R.; Reifarth, R.; Schumann, D.; Ullmann, J. L.; Wallner, A.

    2015-10-01

    The neutron capture cross section of the s -process branch nucleus 63Ni affects the abundances of other nuclei in its region, especially 63Cu and 64Zn. In order to determine the energy-dependent neutron capture cross section in the astrophysical energy region, an experiment at the Los Alamos National Laboratory has been performed using the calorimetric 4 π BaF2 array DANCE. The (n ,γ ) cross section of 63Ni has been determined relative to the well-known 197Au standard with uncertainties below 15%. Various 63Ni resonances have been identified based on the Q value. Furthermore, the s -process sensitivity of the new values was analyzed with the new network calculation tool NETZ.

  5. Photon scattering cross sections of H2 and He measured with synchrotron radiation

    NASA Technical Reports Server (NTRS)

    Ice, G. E.

    1977-01-01

    Total (elastic + inelastic) differential photon scattering cross sections have been measured for H2 gas and He, using an X-ray beam. Absolute measured cross sections agree with theory within the probable errors. Relative cross sections (normalized to theory at large S) agree to better than one percent with theoretical values calculated from wave functions that include the effect of electron-electron Coulomb correlation, but the data deviate significantly from theoretical independent-particle (e.g., Hartree-Fock) results. The ratios of measured absolute He cross sections to those of H2, at any given S, also agree to better than one percent with theoretical He-to-H2 cross-section ratios computed from correlated wave functions. It appears that photon scattering constitutes a very promising tool for probing electron correlation in light atoms and molecules.

  6. Interactions of relativistic neon to nickel projectiles in hydrogen, elemental production cross sections

    NASA Astrophysics Data System (ADS)

    Knott, C. N.; Albergo, S.; Caccia, Z.; Chen, C.-X.; Costa, S.; Crawford, H. J.; Cronqvist, M.; Engelage, J.; Ferrando, P.; Fonte, R.; Greiner, L.; Guzik, T. G.; Insolia, A.; Jones, F. C.; Lindstrom, P. J.; Mitchell, J. W.; Potenza, R.; Romanski, J.; Russo, G. V.; Soutoul, A.; Testard, O.; Tull, C. E.; Tuvé, C.; Waddington, C. J.; Webber, W. R.; Wefel, J. P.

    1996-01-01

    This paper reports the elemental production cross sections for 17 projectile-energy combinations with energies between 338 and 894 MeV/nucleon interacting in a liquid hydrogen target. These results were obtained from two runs at the LBL Bevalac using projectiles ranging from 22Ne to 58Ni. Cross sections were measured for all fragment elements with charges greater than or equal to half the charge of the projectile. The results show that, over the energy and ion range investigated, the general decrease in cross section with decreasing fragment charge is strongly modified by the isospin of the projectile ion. Significant additional modifications of the cross sections due to the internal structure of the nucleus have also been seen. These include both pairing and shell effects. Differences in the cross sections due to the differing energies of the projectile are also considerable.

  7. Electron-Molecule Cross Sections for Plasma Applications: the Role of Internal Energy of the Target

    NASA Astrophysics Data System (ADS)

    Capitelli, M.; Celiberto, R.

    The role of internal excitation in affecting electron-molecule cross sections is analyzed for H2, N2 and O2 systems. Particula emphasis is given to the role of vibrational energy in affecting both resonant and non-resonant electron molecule cross sections. In general for resonant transitions the cross sections dramatically depends on the initial vibrational quantum number of the target, while a minor effect if found for direct (non-resonant) transitions. Cross sections in this last case reflect the form of Franck-Condon factors and Franck-Condon densities linking the relevant boun-bound or bound-continuum transitions. A similar behaviour is presented when the target is electronically excited. In this case, however, the enhancement of cross section is much higher.

  8. Positive Effect of Large Birth Intervals on Early Childhood Hemoglobin Levels in Africa Is Limited to Girls: Cross-Sectional DHS Study

    PubMed Central

    Afeworki, Robel; Smits, Jeroen; Tolboom, Jules; van der Ven, Andre

    2015-01-01

    Background Short birth intervals are independently associated with increased risk of adverse maternal, perinatal, infant and child outcomes. Anemia in children, which is highly prevalent in Africa, is associated with an increased risk of morbidity and mortality. Birth spacing is advocated as a tool to reduce anemia in preschool African children, but the role of gender differences and contextual factors has been neglected. The present study aims to determine to what extent the length of preceding birth interval influences the hemoglobin levels of African preschool children in general, as well as for boys and girls separately, and which contextual factors thereby play a crucial role. Methods and Findings This cross-sectional study uses data from Demographic and Health Surveys (DHS) conducted between 2003 and 2011 in 20 African countries. All preschool children aged 6–59 months with a valid hemoglobin measurement and a preceding birth interval of 7–72 months as well as their corresponding multigravida mothers aged 21–49 years were included in the study. Hemoglobin levels of children and mothers were measured in g/l, while birth intervals were calculated as months difference between consecutive births. Multivariate analyses were done to examine the relationship between length of preceding birth interval and child hemoglobin levels, adjusted for factors at the individual, household, community, district, and country level. A positive linear relationship was observed between birth interval and the 49,260 included children’s hemoglobin level, whereby age and sex of the child, hemoglobin level of the mother, household wealth, mother’s education and urbanization of place of residence also showed positive associations. In the interaction models, the effect of a month increase in birth interval is associated with an average increase of 0.025 g/l in hemoglobin level (P = 0.001) in girls, while for boys the effect was not significant. In addition, for girls, the effect

  9. Scattered light and accuracy of the cross-section measurements of weak absorptions: Gas and liquid phase UV absorption cross sections of CH3CFCl2

    NASA Technical Reports Server (NTRS)

    Fahr, A.; Braun, W.; Kurylo, M. J.

    1993-01-01

    Ultraviolet absorption cross sections of CH3CFCl2(HCFC-141b) were determined in the gas phase (190-260 nm) and liquid phase (230-260 mm) at 298 K. The liquid phase absorption cross sections were then converted into accurate gas phase values using a previously described procedure. It has been demonstrated that scattered light from the shorter-wavelength region (as little as several parts per thousand) can seriously compromise the absorption cross-section measurement, particularly at longer wavelengths where cross sections are low, and can be a source of discrepancies in the cross sections of weakly absorbing halocarbons reported in the literature. A modeling procedure was developed to assess the effect of scattered light on the measured absorption cross section in our experiments, thereby permitting appropriate corrections to be made on the experimental values. Modeled and experimental results were found to be in good agreement. Experimental results from this study were compared with other available determinations and provide accurate input for calculating the atmospheric lifetime of HCFC-141b.

  10. Cross-sectional geometry of the dentary in bats.

    PubMed

    Dumont, Elizabeth R; Nicolay, Christopher W

    2006-01-01

    Bats exhibit remarkable diversity in dietary habits, with species specializing on insects, fruit, nectar, vertebrates and blood. Studies of larger mammals have shown that structural differences in dentary cross-sectional properties exist among species with different diets. Unfortunately, few of these studies have considered the role of phylogeny in shaping these apparent form-function associations. Here we ask whether a relationship exists between diet and dentary structure in bats when phylogenetic history is factored into the analysis. To answer this question, we compared results from phylogenetic generalized least squares (PGLS) and traditional (nonphylogenetic) regression analyses of dentary cross-sectional shape in frugivorous, nectarivorous, and insectivorous bats (253 individuals representing 72 species). Cross-sectional moments of inertia of the dentary between M(1) and M(2) were computed from bone densitometry scans of skeletal specimens. Traditional regressions of cross-sectional parameters against dentary length detected significant departures from isometry among frugivores. In contrast, PGLS analyses indicated that cross-sectional variables for each dietary group scaled with isometry. Thus, the allometric patterns illuminated by traditional statistics are linked to the phylogenetic structure of the sample. Identical patterns of significant differences in slopes and intercepts between frugivores and nectarivores emerged from both traditional and PGLS analyses. As predicted, the cross-sectional shape of the dentary in frugivores is consistent with increased resistance to torsion and bending, while that of nectarivores suggested a less resistant dentary. Although traditional and PGLS analyses yielded some similar results, the phylogenetic structure of a sample can drive apparent patterns of scaling and should be considered in comparative functional analyses.

  11. Stellar neutron capture cross sections of the Ba isotopes

    NASA Astrophysics Data System (ADS)

    Voss, F.; Wisshak, K.; Guber, K.; Käppeler, F.; Reffo, G.

    1994-11-01

    The neutron capture cross sections of 134Ba, 135Ba, 136Ba, and 137Ba were measured in the energy range from 5 to 225 keV at the Karlsruhe 3.75 MV Van de Graaff accelerator. Neutrons were produced via the 7Li (p,n)7 Be reaction by bombarding metallic Li targets with a pulsed proton beam. Capture events were registered with the Karlsruhe 4π barium fluoride detector. The cross section ratios were determined with an overall uncertainty of ~3%, an improvement by factors of 5 to 8 compared to existing data. Severe discrepancies were found with respect to previous results. As a new possibility in time of flight experiments, isomeric cross section ratios could be determined for 135Ba, 136Ba, and 137Ba. Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT=10 keV and 100 keV. These stellar cross sections were used in an s-process analysis. For the s-only isotopes 134Ba and 136Ba the Ns<σ> ratio was determined to 0.875+/-0.025. Hence, a significant branching of the s-process path at 134Cs can be claimed for the first time, in contrast to predictions from the classical approach. This branching yields information on the s-process temperature, indicating values around T8=2. The new cross sections are also important for the interpretation of barium isotopic anomalies, which were recently discovered in SiC grains of carbonaceous chondrite meteorites. Together with the results from previous experiments on tellurium and samarium, a general improvement of the Ns<σ> systematics in the mass range A=120-150 is achieved. This yields a more reliable separation of s- and r-process contributions for comparison with stellar observations, but reveals a 20% discrepancy with respect to the solar barium abundance.

  12. The solar neutrino capture cross section for 81Br

    NASA Astrophysics Data System (ADS)

    Haxton, W. C.

    1981-09-01

    The solar neutrino capture rate for the reaction 81Br + νe --> 81Kr + e- is calculated for the standard solar and weak interaction models. The results show that the capture cross section is dominated by the lowest Gamow-Teller transition to the metastable 1/2- (0.190 MeV) state in 81Kr. As the inverse electron capture rate for this transition has been measured recently, one can then argue that the cross section is well determined experimentally. Thus uncertainties in nuclear physics should not be an obstacle to the recently proposed 81Br radiochemical measurement of the 7Be solar neutrino flux. Present address.

  13. Uncertainty quantification in fission cross section measurements at LANSCE

    DOE PAGES

    Tovesson, F.

    2015-01-09

    Neutron-induced fission cross sections have been measured for several isotopes of uranium and plutonium at the Los Alamos Neutron Science Center (LANSCE) over a wide range of incident neutron energies. The total uncertainties in these measurements are in the range 3–5% above 100 keV of incident neutron energy, which results from uncertainties in the target, neutron source, and detector system. The individual sources of uncertainties are assumed to be uncorrelated, however correlation in the cross section across neutron energy bins are considered. The quantification of the uncertainty contributions will be described here.

  14. The 237U(n,f) Cross Section

    SciTech Connect

    Younes, W; Britt, H C; Wilhelmy, J B

    2003-03-03

    The purpose of this note is to combine existing information on the {sup 237}U(n,f) cross section to determine if some consistency can be obtained for the neutron induced fission excitation of {sup 237}U. The neutron induced fission cross section of the 6.8 day {sup 237}U was measured directly by McNally et al. in 1968 using the Pommard nuclear device test. At the same time critical assembly measurements were done at Los Alamos using the Flattop assembly. A previous measurement was also made at LASL in 1954 with two different neutron sources, each peaked near 200 keV. The results were 0.66 {+-} 0.10 b and 0.70 {+-} 0.07 b for the (n,f) cross section. More recently Younes and Britt have reanalyzed direct reaction charged particle data of Cramer and Britt that had determined the fission probability of the {sup 238}U compound nucleus as a function of nuclear excitation energy. They have combined fission probabilities with calculated neutron absorption cross sections, including corrections for the differences in angular momentum between the direct and neutron induced reactions. From this analysis they have extracted equivalent {sup 237}U(n,f) cross sections. The technique for extracting surrogate (n,f) cross sections from (t,pf) data has been demonstrated in a recent publication for the test case {sup 235}U(n,f). In addition to this experimental information, Lynn and Hayes have recently done a new theoretical study of the fission cross sections for a series of isotopes in this region. A summary plot of the data is shown in Fig. 1. Below 0.5 MeV the McNally, Cowan, and Younes-Britt results are in reasonable agreement. The average cross section in the Younes-Britt results, for En = 0.1 to 0.4 MeV, is 0.80 times the McNally values which is well within the errors of the McNally experiment. Above 0.5 MeV the McNally results diverge toward higher values. It should be noted that this divergence begins approximately at the {sup 237}Np threshold and that {sup 237}Np is the

  15. Ozone absorption cross section measurements in the Wulf bands

    NASA Technical Reports Server (NTRS)

    Anderson, Stuart M.; Hupalo, Peter; Mauersberger, Konrad

    1993-01-01

    A tandem dual-beam spectrometer has been developed to determine ozone absorption cross sections for 13 selected wavelengths between 750 and 975 nm at room temperature. The increasingly pronounced structure in this region may interfere with atmospheric trace gas transitions that are useful for remote sensing and complicate the measurement of aerosols. Ozone concentrations were determined by absorption at the common HeNe laser transition near 632.8 nm using the absolute cross section reported previously. The overall accuracy of these room temperature measurements is generally better than 2 percent. A synoptic near-IR spectrum scaled to these measurements is employed for comparison with results of previous studies.

  16. Cross-sectional imaging of the thyroid gland.

    PubMed

    Loevner, Laurie A; Kaplan, Summer L; Cunnane, Mary Elizabeth; Moonis, Gul

    2008-08-01

    Directed imaging is useful in assessing the thyroid gland. Nuclear scintigraphy reveals functional information about the thyroid gland, while cross-sectional imaging, including ultrasound, CT, and MR imaging provide important adjunctive anatomic information about the thyroid as well as about related structures in the neck, including the presence or absence of cervical and mediastinal lymphadenopathy, or extension of thyroid disease into adjacent soft tissues or the mediastinum. This article reviews the anatomy and physiology of the thyroid gland and addresses issues related to diseases affecting the thyroid gland, with an emphasis on neoplasms and the role of cross-sectional MR and CT imaging in the assessment of thyroid neoplasia.

  17. Absolute Photoionization Cross Sections of Two Cyclic Ketones: Cyclopentanone & Cyclohexanone.

    PubMed

    Price, Chelsea; Fathi, Yasmin; Meloni, Giovanni

    2017-02-23

    Absolute photoionization cross sections for cyclopentanone and cyclohexanone, as well as partial ionization cross sections for the dissociative ionized fragments, are presented in this investigation. Experiments are performed via a multiplexed photoionization mass spectrometer utilizing VUV synchrotron radiation supplied by the Advanced Light Source of Lawrence Berkeley National Laboratory. These results allow the quantification of these species that is relevant to investigate the kinetics and combustion reactions of potential biofuels. The CBS-QB3 calculated values for the adiabatic ionization energies agree well with the experimental values and the identification of possible dissociative fragments is discussed for both systems.

  18. Neutron removal cross section as a measure of neutron skin

    SciTech Connect

    Fang, D. Q.; Ma, Y. G.; Cai, X. Z.; Tian, W. D.; Wang, H. W.

    2010-04-15

    We study the relation between neutron removal cross section (sigma{sub -N}) and neutron skin thickness for finite neutron-rich nuclei using the statistical abrasion ablation model. Different sizes of neutron skin are obtained by adjusting the diffuseness parameter of neutrons in the Fermi distribution. It is demonstrated that there is a good linear correlation between sigma{sub -N} and the neutron skin thickness for neutron-rich nuclei. Further analysis suggests that the relative increase of neutron removal cross section could be used as a quantitative measure for neutron skin thickness in neutron-rich nuclei.

  19. Cross section expansion for direct neutron radiative capture

    SciTech Connect

    Baye, D.

    2004-07-01

    Cross sections for neutron radiative capture multiplied by the relative velocity can be expressed as a Taylor expansion in powers of the relative energy. The coefficients of this expansion are expressed in the potential model as integrals involving solutions of the radial Schroedinger equation and of its inhomogeneous energy derivatives calculated at zero energy. Similarities and differences with charged-particle capture are emphasized. The {sup 12}C(n,{gamma}){sup 13}C capture reaction is treated as an example. The coefficients of the Taylor expansion lead to simple parametrizations of the experimental partial cross sections for neutron capture to each {sup 13}C bound state.

  20. Total cross section of electron scattering by fluorocarbon molecules

    NASA Astrophysics Data System (ADS)

    Yamada, T.; Ushiroda, S.; Kondo, Y.

    2008-12-01

    A compact linear electron transmission apparatus was used for the measurement of the total electron scattering cross section at 4-500 eV. Total cross sections of chlorofluorocarbon (CCl2F2), hydrochlorofluorocarbon (CHClF2), perfluoropropane (C3F8), perfluoro-n-pentane (C5F12), perfluoro-n-hexane (C6F14) and perfluoro-n-octane (C8F18) were obtained experimentally and compared with the values obtained from a theoretical calculation and semi-empirical model calculation.

  1. Measurements of (n,{gamma}) cross sections with small samples

    SciTech Connect

    Koehler, P.E.; Kaeppeler, F.

    1995-02-05

    Neutron capture cross section data for certain isotopes of very small natural abundance are crucial for a better understanding of the s- and p-processes of nucleosynthesis. Also, recent work has shown that many previous (n,{gamma}) measurements need to be extended to lower neutron energies and that the accuracy of some previous data need to be improved. At Los Alamos we have developed a system for measuring (n,{gamma}) cross sections on samples as small as 1 mg. We give examples of measurements made with this apparatus and discuss the nuclear astrophysics motivation for these and future measurements.

  2. Measurements of (n,{gamma}) cross sections with small samples

    SciTech Connect

    Koehler, P.E.; Kaeppeler, F.

    1994-09-01

    Neutron capture cross section data for certain isotopes of very small natural abundance are crucial for a better understanding of the s- and p-processes of nucleosynthesis. Also, recent work has shown that many previous (n,{gamma}) measurements need to be extended to lower neutron energies and that the accuracy of some previous data need to be improved. At Los Alamos the authors have developed a system for measuring (n,{gamma}) cross sections on samples as small as 1 mg. They give examples of measurements made with this apparatus and discuss the nuclear astrophysics motivation for these and future measurements.

  3. Hadronic absorption cross sections of B{sub c}

    SciTech Connect

    Lodhi, M. A. K.; Akram, Faisal; Irfan, Shaheen

    2011-09-15

    The cross sections of B{sub c} absorption by {pi} mesons are calculated using a hadronic Lagrangian based on the SU(5) flavor symmetry. Calculated cross sections are found to be in the ranges 2-7 mb and 0.2-2 mb for the processes B{sub c}{sup +}{pi}{yields}DB and B{sub c}{sup +}{pi}{yields}D*B*, respectively, when the monopole form factor is included. These results could be useful in calculating the production rate of B{sub c} mesons in relativistic heavy ion collisions.

  4. Differential Cross Sections for Proton-Proton Elastic Scattering

    NASA Technical Reports Server (NTRS)

    Norman, Ryan B.; Dick, Frank; Norbury, John W.; Blattnig, Steve R.

    2009-01-01

    Proton-proton elastic scattering is investigated within the framework of the one pion exchange model in an attempt to model nucleon-nucleon interactions spanning the large range of energies important to cosmic ray shielding. A quantum field theoretic calculation is used to compute both differential and total cross sections. A scalar theory is then presented and compared to the one pion exchange model. The theoretical cross sections are compared to proton-proton scattering data to determine the validity of the models.

  5. Light ray tracing through a leaf cross section

    NASA Technical Reports Server (NTRS)

    Kumar, R.; Silva, L. F.

    1973-01-01

    A light ray, incident at about 5 deg to the normal, is geometrically plotted through the drawing of the cross section of a soybean leaf using Fresnel's equations and Snell's law. The optical mediums of the leaf considered for ray tracing are: air, cell sap, chloroplast, and cell wall. The ray is also drawn through the same leaf cross section with cell wall and air as the only optical mediums. The values of the reflection and transmission found from the ray tracing tests agree closely with the experimental results obtained using a Beckman Dk-2A Spectroreflector.

  6. Neutron capture cross section standards for BNL 325, Fourth Edition

    SciTech Connect

    Holden, N.E.

    1981-01-01

    This report evaluates the experimental data and recommends values for the thermal neutron cross sections and resonance integrals for the neutron capture reactions: /sup 55/Mn(n,..gamma..), /sup 59/Co(n,..gamma..) and /sup 197/Au(n,..gamma..). The failure of lithium and boron as standards due to the natural variation of the absorption cross sections of these elements is discussed. The Westcott convention, which describes the neutron spectrum as a thermal Maxwellian distribution with an epithermal component, is also discussed.

  7. Propagation of sound waves in tubes of noncircular cross section

    NASA Technical Reports Server (NTRS)

    Richards, W. B.

    1986-01-01

    Plane-acoustic-wave propagation in small tubes with a cross section in the shape of a flattened oval is described. Theoretical descriptions of a plane wave propagating in a tube with circular cross section and between a pair of infinite parallel plates, including viscous and thermal damping, are expressed in similar form. For a wide range of useful duct sizes, the propagation constant (whose real and imaginary parts are the amplitude attenuation rate and the wave number, respectively) is very nearly the same function of frequency for both cases if the radius of the circular tube is the same as the distance between the parallel plates. This suggests that either a circular-cross-section model or a flat-plate model can be used to calculate wave propagation in flat-oval tubing, or any other shape tubing, if its size is expressed in terms of an equivalent radius, given by g = 2 x (cross-sectional area)/(length of perimeter). Measurements of the frequency response of two sections of flat-oval tubing agree with calculations based on this idea. Flat-plate formulas are derived, the use of transmission-line matrices for calculations of plane waves in compound systems of ducts is described, and examples of computer programs written to carry out the calculations are shown.

  8. A cross-sectional study of the effect of health literacy on diabetes prevention and control among elderly individuals with prediabetes in rural China

    PubMed Central

    Qin, Lulu; Xu, Huilan

    2016-01-01

    Objectives This study was designed to examine the effect of health literacy on diabetes prevention and control and risk factors for low diabetes health literacy among elderly individuals with prediabetes in rural areas in China. Design setting and participates A cross-sectional survey was conducted among elderly individuals in rural communities in Yiyang City in China. Multi-staged cluster random sampling was used to select 42 areas and 434 individuals with prediabetes who were interviewed using a questionnaire on diabetes health literacy in China. Main outcome measures Participants were asked for general information (age, gender, marital status, history of hyperglycaemia, family history of diabetes mellitus, presence of other diseases and level of education). Binary logistic regression analysis was used to identify risk factors for poor health literacy concerning diabetes prevention and control among elderly subjects with prediabetes. Results The median health literacy score for diabetes prevention and prediabetes control was 10.0 (IQR 7.0–13.0). The level of diabetes health literacy among men was lower than among women (OR 2.831, 95% CI 1.818 to 4.408), and lower among respondents with 1–6 years of education than among those with 6 years or more of education (OR 14.274, 95% CI 5.927 to 34.375). Those with less than 1 year of education had the lowest literacy (OR 31.148, 95% CI 11.661 to 83.204). The level of diabetes health literacy among elderly individuals with prediabetes but no history of hyperglycaemia was lower than among those with a history of hyperglycaemia (OR 2.676, 95% CI 1.101 to 6.504). Conclusions Health literacy concerning diabetes prevention and control among elderly individuals with prediabetes was very low in rural China. Appropriate health education for elderly individuals with low educational levels should be incorporated into diabetes prevention efforts. Trial registration number ChiCTR-IOR-15007033; Results. PMID:27235299

  9. Froissart bound on inelastic cross section without unknown constants

    NASA Astrophysics Data System (ADS)

    Martin, André; Roy, S. M.

    2015-04-01

    Assuming that axiomatic local field theory results hold for hadron scattering, André Martin and S. M. Roy recently obtained absolute bounds on the D wave below threshold for pion-pion scattering and thereby determined the scale of the logarithm in the Froissart bound on total cross sections in terms of pion mass only. Previously, Martin proved a rigorous upper bound on the inelastic cross-section σinel which is one-fourth of the corresponding upper bound on σtot, and Wu, Martin, Roy and Singh improved the bound by adding the constraint of a given σtot. Here we use unitarity and analyticity to determine, without any high-energy approximation, upper bounds on energy-averaged inelastic cross sections in terms of low-energy data in the crossed channel. These are Froissart-type bounds without any unknown coefficient or unknown scale factors and can be tested experimentally. Alternatively, their asymptotic forms, together with the Martin-Roy absolute bounds on pion-pion D waves below threshold, yield absolute bounds on energy-averaged inelastic cross sections. For example, for π0π0 scattering, defining σinel=σtot-(σπ0π0→π0π0+σπ0π0→π+π-) , we show that for c.m. energy √{s }→∞, σ¯ inel(s ,∞)≡s ∫s∞d s'σinel(s')/s'2≤(π /4 )(mπ)-2[ln (s /s1)+(1 /2 )ln ln (s /s1)+1 ]2 where 1 /s1=34 π √{2 π }mπ-2 . This bound is asymptotically one-fourth of the corresponding Martin-Roy bound on the total cross section, and the scale factor s1 is one-fourth of the scale factor in the total cross section bound. The average over the interval (s,2s) of the inelastic π0π0 cross section has a bound of the same form with 1 /s1 replaced by 1 /s2=2 /s1.

  10. Radial Eigenmodes for a Toroidal Waveguide with Rectangular Cross Section

    SciTech Connect

    Rui Li

    2012-07-01

    In applying mode expansion to solve the CSR impedance for a section of toroidal vacuum chamber with rectangular cross section, we identify the eigenvalue problem for the radial eigenmodes which is different from that for cylindrical structures. In this paper, we present the general expressions of the radial eigenmodes, and discuss the properties of the eigenvalues on the basis of the Sturm-Liouville theory.

  11. 42. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

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

    42. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION 8, BUILDINGS NO. H-1 TO H-10 INCL., GRINDING, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (NashVille, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  12. 35. Photograph of a line drawing. 'CROSS SECTION OF PART ...

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

    35. Photograph of a line drawing. 'CROSS SECTION OF PART III, SECTION 1, EQUIPMENT LAYOUT, BUILDINGS E-1 TO E-10 INCL., WASHING, MANUFACTURING AREA, PLANT 'B'.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  13. 34. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

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

    34. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION B, BUILDINGS NO. E-1 TO E-10 INCL., WASHING, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  14. 29. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

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

    29. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION 8, BUILDINGS NO. D-1 TO D-10 INCL., NITRATION, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  15. 30. Photograph of a line drawing. 'CROSS SECTION OF PART ...

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

    30. Photograph of a line drawing. 'CROSS SECTION OF PART III, SECTION 1, EQUIPMENT LAYOUT, BUILDINGS D-1 TO D-10 INCL., NITRATION, MANUFACTURING AREA, PLANT 'B'.' From U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  16. SCWR Once-Through Calculations for Transmutation and Cross Sections

    SciTech Connect

    ganda, francesco

    2012-07-01

    It is the purpose of this report to document the calculation of (1) the isotopic evolution and of (2) the 1-group cross sections as a function of burnup of the reference Super Critical Water Reactor (SCWR), in a format suitable for the Fuel Cycle Option Campaign Transmutation Data Library. The reference SCWR design was chosen to be that described in [McDonald, 2005]. Super Critical Water Reactors (SCWR) are intended to operate with super-critical water (i.e. H2O at a pressure above 22 MPa and a temperature above 373oC) as a cooling – and possibly also moderating – fluid. The main mission of the SCWR is to generate lower cost electricity, as compared to current standard Light Water Reactors (LWR). Because of the high operating pressure and temperature, SCWR feature a substantially higher thermal conversion efficiency than standard LWR – i.e. about 45% versus 33%, mostly due to an increase in the exit water temperature from ~300oC to ~500oC – potentially resulting in a lower cost of generated electricity. The coolant remains single phase throughout the reactor and the energy conversion system, thus eliminating the need for pressurizers, steam generators, steam separators and dryers, further potentially reducing the reactor construction capital cost. The SCWR concept presented here is based on existing LWR technology and on a large number of existing fossil-fired supercritical boilers. However, it was concluded in [McDonald, 2005], that: “Based on the results of this study, it appears that the reference SCWR design is not feasible.” This conclusion appears based on the strong sensitivity of the design to small deviations in nominal conditions leading to small effects having a potentially large impact on the peak cladding temperature of some fuel rods. “This was considered a major feasibility issue for the SCWR” [McDonald, 2005]. After a description of the reference SCWR design, the Keno V 3-D single assembly model used for this analysis, as well as the

  17. Reaction cross sections of intermediate energy {alpha} particles within a relativistic optical model

    SciTech Connect

    Ait-Tahar, S.; Nedjadi, Y.

    1995-07-01

    The suggestion made recently by H. Abele {ital et} {ital al}. that relativistic effects in the interaction of alpha particles with various nuclei at intermediate energies may remove the existing discrepancy between the theoretical predictions and the experimental data for the reaction cross section is investigated. We use a relativistic model based on the Kemmer-Duffin-Petiau equation and find that relativistic effects do not lead to a reduction in the reaction cross section within the present approach. Alternative explanations are discussed.

  18. Fission, total and neutron capture cross section measurements at ORELA

    SciTech Connect

    Guber, K.H.; Spencer, R.R.; Leal, L.C.; Larson, D.C.; Dos Santos, G.; Harvey, J.A.; Hill, N.W.

    1998-08-01

    In support of the Nuclear Criticality Predictability Program established in response to the Defense Nuclear Facility Safety Board Recommendation 93-2, time-of-flight (TOF) measurements of the fission cross sections of {sup 233}U in the neutron energy range from 0.36 eV to several hundred keV have been initiated at the Oak Ridge Electron Linear Accelerator (ORELA). Also total and capture cross sections of Al, Cl, and K in the energy range from about 100 eV to several hundred keV have been measured or are under way. The goal is to derive accurate cross section representations for the materials involved in criticality calculations of fuel storage, transportation, etc., configurations. Additional high-resolution measurements of the total cross sections of {sup 233}U below a few keV neutron energy are being planned for 1998, as well as for the other involved material. Evaluated data files in ENDF-6 format will be processed into formats for use in criticality analysis and utilized in benchmark data testing. Finally the data will be submitted for inclusion in ENDF/B.

  19. Electron-silane scattering cross section for plasma assisted processes

    NASA Astrophysics Data System (ADS)

    Verma, Pankaj; Kaur, Jaspreet; Antony, Bobby

    2017-03-01

    Silane is an important molecule with numerous applications to natural and technological plasmas. In such environments, where plasma assisted processes are vital, electron induced reactions play a major role in its chemistry. In view of this, electron induced scattering of molecules such as silane finds significance. This article reports a comprehensive study of electron impact cross sections for silane over a wide energy range. In particular, the emphasis is given in providing a complete dataset for various electron scattering events possible with silane. Such dataset is the need for the plasma modeling community. Moreover, literature survey shows that the cross section database for silane is fragmentary. To fill this void, we have computed the differential elastic, total, rotational excitation, and momentum transfer cross sections. Two formalisms that are reliable in their energy domain are employed to accomplish the task: the R-matrix method through QUANTEMOL-N at low incident energies and the spherical complex optical potential formalism at intermediate to high energies. Interestingly, the comparison of the present cross section exhibits a good concurrence with the previous data, wherever available.

  20. Skin Diseases: Cross-section of human skin

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Cross-section of human skin Past Issues / Fall 2008 Table of Contents For ... Logical Images, Inc. I n the areas of skin health and skin diseases, the NIH's National Institute ...

  1. 35. 'Firing Pier, Cross Sections, Looking South,' submitted 29 December ...

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

    35. 'Firing Pier, Cross Sections, Looking South,' submitted 29 December 1941 by John Brackett, Consulting Engineer, to Public Works Department, Bureau of Yards & Docks. PW Drawing 3874-46, Y&D Drawing 190848. Scale 1/8' = 1'. - Naval Torpedo Station, Firing Pier, North end of Gould Island in Narragansett Bay, Newport, Newport County, RI

  2. Stellar neutron capture cross sections of the Lu isotopes

    SciTech Connect

    Wisshak, K.; Voss, F.; Kaeppeler, F.; Kazakov, L.

    2006-01-15

    The neutron capture cross sections of {sup 175}Lu and {sup 176}Lu have been measured in the energy range 3-225 keV at the Karlsruhe 3.7 MV Van de Graaff accelerator. Neutrons were produced via the {sup 7}Li(p,n){sup 7}Be reaction by bombarding metallic Li targets with a pulsed proton beam, and capture events were registered with the Karlsruhe 4{pi} barium fluoride detector. The cross sections were determined relative to the gold standard using isotopically enriched as well as natural lutetium oxide samples. Overall uncertainties of {approx}1% could be achieved in the final cross section ratios to the gold standard, about a factor of 5 smaller than in previous works. Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT = 8 and 100 keV. These values are systematically larger by {approx}7% than those reported in recent evaluations. These results are of crucial importance for the assessment of the s-process branchings at A 175/176.

  3. Stellar neutron capture cross sections of the tin isotopes

    SciTech Connect

    Wisshak, K.; Voss, F.; Theis, C.; Kaeppeler, F.; Guber, K.; Kazakov, L.; Kornilov, N.; Reffo, G.

    1996-09-01

    The neutron capture cross sections of {sup 114}Sn, {sup 115}Sn, {sup 116}Sn, {sup 117}Sn, {sup 118}Sn, and {sup 120}Sn were measured in the energy range from 3 to 225 keV at the Karlsruhe 3.75 MV Van de Graaff accelerator. Neutrons were produced via the {sup 7}Li({ital p},{ital n}){sup 7}Be reaction using a pulsed proton beam. Capture events were registered with the Karlsruhe 4{pi} barium fluoride detector. The experiment was complicated by the small ({ital n},{gamma}) cross sections of the proton magic tin isotopes and by the comparably low enrichment of the rare isotopes {sup 114}Sn and {sup 115}Sn. Despite significant corrections for capture of scattered neutrons and for isotopic impurities, the high efficiency and the spectroscopic quality of the BaF{sub 2} detector allowed the determination of the cross-section ratios with overall uncertainties of 1{endash}2{percent}, five times smaller compared to existing data. Based on these results, Maxwellian averaged ({ital n},{gamma}) cross sections were calculated for thermal energies between {ital kT}=10 and 100 keV. These data are used for a discussion of the solar tin abundance and for an improved determination of the isotopic {ital s}- and {ital r}-process components. {copyright} {ital 1996 The American Physical Society.}

  4. RZ calculations for self shielded multigroup cross sections

    SciTech Connect

    Li, M.; Sanchez, R.; Zmijarevic, I.; Stankovski, Z.

    2006-07-01

    A collision probability method has been implemented for RZ geometries. The method accounts for white albedo, specular and translation boundary condition on the top and bottom surfaces of the geometry and for a white albedo condition on the outer radial surface. We have applied the RZ CP method to the calculation of multigroup self shielded cross sections for Gadolinia absorbers in BWRs. (authors)

  5. Electron Impact Ionization Cross Sections of n-decane

    NASA Astrophysics Data System (ADS)

    Jiao, Charles; Dejoseph, Charles; Garscadden, Alan

    2001-10-01

    The ionization and dissociation of hydrocarbon fuels with various plasma excitation schemes including pulsed high E/n discharges have been proposed to alleviate the problem of ignition in supersonic flow combustors and operations at high altitudes. The fuel which is also used for cooling, must not pyrolyse at operational temperatures. We have examined the electron ionization collision processes in n-decane using high resolution Fourier transform mass spectrometry that permits measurements of the 24 ions with cross sections larger than 10-19cm2. These generally fall into two broad categories: those with five or more carbon atoms whose ionization cross sections rise rapidly and essentially saturate within twice the appearance potential and those with four carbon atoms and less whose cross sections rise more gradually and are only saturating at energies above 70 eV. The total ionization cross section is large, rising to 7x10-16cm2. Studies were made with deuterated samples to distinguish the potential mechanisms in fragment ion induced dissociation of the parent gas. The results are compared with similar data for octane.

  6. Pion Charge Exchange Cross Section on Liquid Argon

    NASA Astrophysics Data System (ADS)

    Nelson, Kevin; LArIAT (FNAL T-1034) Collaboration

    2017-01-01

    The observation of neutrino oscillations allows charge parity violation to be probed in the neutrino sector. Detectors with high calorimetric energy resolution and high spatial resolution will provide precise measurements of neutrino oscillations. By measuring small π+/- cross sections for individual interaction channels, specifically charge exchange, we will make a measurement in the first of its kind on liquid Argon and demonstrate the physics capabilities of a relatively new detector technology: the Liquid Argon Time Projection Chamber (LAr TPC). This analysis will report on the thin slab cross section measurement technique and the Monte Carlo cross section measurements in the energy range of 0.2 - 1.0 GeV. This analysis is the first iteration in classifying charge exchange events from a sample of incident pions, and it aims to identify events in which a π0 was produced without any charged pions leaving the interaction vertex. We will also report on the methodology and efficiency of this algorithm in identifying particles and their interactions in liquid argon. This analysis will inform a future measurement of the π+/- charge exchange cross section on liquid argon. This work was supported in part by the National Science Foundation under Grant No. PHY-1359364.

  7. The Inclusive Neutrino Charged Current Cross Section Measured in NOMAD

    NASA Astrophysics Data System (ADS)

    Godley, Andrew; Wu, Qun; Mishra, Sanjib

    2007-04-01

    The inclusive charged current cross section of muon neutrino interactions is measured as a function of energy using the NOMAD data. The significance of this measurement is its precision below 30 GeV, a region not previously well covered and of importance to current and proposed neutrino experiments. The procedure and results of the measurement will be presented.

  8. Radar cross sections of standard and complex shape targets

    NASA Technical Reports Server (NTRS)

    Sohel, M. S.

    1974-01-01

    The theoretical, analytical, and experimental results are described for radar cross sections (RCS) of different-shaped targets. Various techniques for predicting RCS are given, and RCS of finite standard targets are presented. Techniques used to predict the RCS of complex targets are made, and the RCS complex shapes are provided.

  9. e+e- → charm cross sections via ISR

    NASA Astrophysics Data System (ADS)

    Pakhlova, Galina

    2010-06-01

    We discuss recent measurements of exclusive e+e- cross sections for charmed hadron final states near threshold performed by Belle and BABAR. The results are based on a study of events with initial-state-radiation photons in a large data sample collected with the Belle and BABAR detectors at the γ(4S) resonance and nearby continuum.

  10. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    SciTech Connect

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Digiovine, B.; Esbensen, H.; Fernandez Niello, J. O.; Henderson, D.; Jiang, C. L.; Lai, J.; Marley, S. T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Paul, M.; Ugalde, C.; Giardina, G.; Eidelman, S.; Venanzoni, G.; Battaglieri, M.; Mandaglio, G.

    2015-06-02

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  11. Theory in evaluation of actinide fission and capture cross sections.

    SciTech Connect

    Lynn, J. E.

    2004-01-01

    The authors discuss the possibilities and limitations of the use of theory as a tool in the evaluation of actinide fission and capture cross-sections. They consider especially the target {sup 235}U as an example. They emphasize the roles of intermediate structure in the fission cross-section and of level width fluctuations in both intermediate structure and fine structure, noting that these lead to a breakdown of Hauser-Feshbach theory at sub-barrier and near barrier energies. At higher energies (where fluctuation-averaged Hauser-Feshbach theory is applicable) semi-quantitative and intuitive representations of transition state spectra and barrier level density functions have to be tested against experimental data wherever these are available. Adjustment of the fission cross-section against inelastic scattering to the much better known levels of the residual nucleus should then lead to a fairly sound estimate of the capture cross-section. They compare such estimates with evaluated and experimental data for {sup 235}U.

  12. Cross sections for low-energy inelastic H + Na collisions

    SciTech Connect

    Belyaev, A. K.; Barklem, P. S.; Dickinson, A. S.; Gadea, F. X.

    2010-03-15

    Full quantum-scattering calculations are reported for low-energy near-threshold inelastic collision cross sections for H+Na. The calculations include transitions between all levels up to and including the ionic state (ion-pair production) for collision energies from the threshold up to 10 eV. These results are important for astrophysical modeling of spectra in stellar atmospheres. Results for the 3s-3p excitation are carefully examined using three different quantum chemistry input data sets, and large differences are found near the threshold. The differences are found to be predominantly due to differences in the radial coupling rather than potentials and are also found not to relate to differences in couplings in a simple manner. In fact, of the three input couplings, the two that are most similar give the cross sections with the largest differences. The 3s-3p cross sections show orbiting resonances which have been seen in earlier studies, while Feshbach resonances associated with closed channels were also found to be present in the low-energy cross sections for some transitions.

  13. A Cross-Sectional Study of Cognitive Variables.

    ERIC Educational Resources Information Center

    Grippin, Pauline; And Others

    Students in grades K, 1, 3, and 5 were administered the Rod and Frame Test (RFT), the Matching Familiar Figures (MFF) Test, and the Piagetian tasks of Discontinuous Quantity, Class Inclusion, Multiplication of Classes, and Multiplication of Relations. Cross-sectional trends were found in all tasks with older children being less impulsive, more…

  14. 11. Photograph of a line drawing. 'CROSS SECTION OF GAS ...

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

    11. Photograph of a line drawing. 'CROSS SECTION OF GAS PRODUCER.' From George R. Cooper (Wilputte Corporation). 'Operating Overview of a Producer Gas Plant (12 Machines) at Kingsport, Tennessee.' Presented at the Fifth Annual International Conference on Coal Gasification, Liquefaction and Conversion to Electricity. University of Pittsburgh, August 2, 1978. - Holston Army Ammunition Plant, Producer Gas Plant, Kingsport, Sullivan County, TN

  15. Measurement of proton inelastic scattering cross sections on fluorine

    NASA Astrophysics Data System (ADS)

    Chiari, M.; Caciolli, A.; Calzolai, G.; Climent-Font, A.; Lucarelli, F.; Nava, S.

    2016-10-01

    Differential cross-sections for proton inelastic scattering on fluorine, 19F(p,p')19F, from the first five excited levels of 19F at 110, 197, 1346, 1459 and 1554 keV were measured for beam energies from 3 to 7 MeV at a scattering angle of 150° using a LiF thin target (50 μg/cm2) evaporated on a self-supporting C thin film (30 μg/cm2). Absolute differential cross-sections were calculated with a method not dependent on the absolute values of collected beam charge and detector solid angle. The validity of the measured inelastic scattering cross sections was then tested by successfully reproducing EBS spectra collected from a thick Teflon (CF2) target. As a practical application of these measured inelastic scattering cross sections in elastic backscattering spectroscopy (EBS), the feasibility of quantitative light element (C, N and O) analysis in aerosol particulate matter samples collected on Teflon by EBS measurements and spectra simulation is demonstrated.

  16. Applications of cross sections for electron-molecule collision processes

    SciTech Connect

    Cartwright, D.C.

    1985-01-01

    The role of electron-molecule collision cross sections is discussed for the study of the ionospheric and auroral processes in planetary atmospheres and of discharge-pumped lasers. These two areas emphasize the importance of further theoretical and experimental studies concerning electron-impact processes. 13 refs., 3 figs., 2 tabs. (WRF)

  17. Complex Correlation Calculation of e-H Total Cross Sections

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Temkin, Aaron; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Calculation of e - H total and elastic partial wave cross sections is being carried out using the complex correlation variational T-matrix method. In this preliminary study, elastic partial wave phase shifts are calculated with the correlation functions which are confined to be real. In that case the method reduces to the conventional optical potential approach with projection operators.

  18. 18. Cross section of Mormon Flat Dam completed. Structure on ...

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

    18. Cross section of Mormon Flat Dam completed. Structure on parapet contains the operating mechanisms for the penstock gates. Power house is not yet under construction. Photographer unknown, 1926. Source: Salt River Project. - Mormon Flat Dam, On Salt River, Eastern Maricopa County, east of Phoenix, Phoenix, Maricopa County, AZ

  19. Experimental absolute cross section for photoionization of Xe^7+

    NASA Astrophysics Data System (ADS)

    Schippers, S.; Müller, A.; Esteves, D.; Habibi, M.; Aguilar, A.; Kilcoyne, A. L. D.

    2010-03-01

    Collision processes with highly charged xenon ions are of interest for UV-radiation generation in plasma discharges, for fusion research and for space craft propulsion. Here we report results for the photoionization of Xe^7+ ionsootnotetextS. Schippers et al., J. Phys.: Conf. Ser. (in print) which were measured at the photon-ion end station of ALS beamline 10.0.1. As compared with the only previous experimental studyootnotetextJ. M. Bizau et al., Phys. Rev. Lett. 84, 435 (2000) of this reaction, the present cross sections were obtained at higher energy resolution (50--80 meV vs. 200--500 meV) and on an absolute cross section scale. In the experimental photon energy range of 95--145 eV the cross section is dominated by resonances associated with 4d->5f excitation and subsequent autoionization. The most prominent feature in the measured spectrum is the 4d^9,s,f, resonance at 121.14±0.02 eV which reaches a peak cross section of 1.2 Gb at 50 meV photon energy spread. The experimental resonance strength of 160 Mb eV (corresponding to an absorption oscillator strength of 1.46) is in fair agreement with the theoretical result^2.

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

    SciTech Connect

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

    1987-04-01

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

  1. 23. Cross section of newly completed concrete channel and trestle ...

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

    23. Cross section of newly completed concrete channel and trestle supported steel flume, 1919. Courtesy of the Mandeville Department of Special Collections, Central Library, University of California, San Diego. - Lake Hodges Flume, Along San Dieguito River between Lake Hodges & San Dieguito Reservoir, Rancho Santa Fe, San Diego County, CA

  2. Neutron capture cross section of {sup 241}Am

    SciTech Connect

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-15

    The neutron capture cross section of {sup 241}Am for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665{+-}33 b. Our result is in good agreement with other recent measurements. Resonance parameters for E{sub n}<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. {gamma}{sub n} neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553{+-}7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  3. Black carbon over Mexico: The effect of atmospheric transport on mixing state, mass absorption cross-section, and BC/CO ratios

    SciTech Connect

    Subramanian, R.; Kok, G. L.; Baumgardner, Darrel; Clarke, A. D.; Shinozuka, Y.; Campos, Teresa; Heizer, CG; Stephens, Britton; de Foy, B.; Voss, Paul B.; Zaveri, Rahul A.

    2010-01-13

    A single particle soot photometer (SP2) was operated on the NCAR C-130 during the MIRAGE campaign (part of MILAGRO), sampling black carbon (BC) over Mexico. The highest BC concentrations were measured over Mexico City (sometimes as much as 2 Fg/m34 ) and over hill fires to the south of the city. The age of plumes outside of Mexico City was determined using a combination of HYSPLIT trajectories, WRF-FLEXPART modeling and CMET balloon tracks. As expected, older, diluted air masses had lower BC concentrations. A comparison of carbon monoxide (CO) and BC suggests a CO background of around 65 ppbv, and a backgroundcorrected BC/COnet ratio of 2.89±0.89 (ng/m39 -STP)/ppbv (average ± standard deviation). This ratio is similar for fresh emissions over Mexico City, as well as for aged airmasses. Comparison of light absorption measured with a particle soot absorption photometer (PSAP) and the SP2 BC suggests a BC mass-normalized absorption cross-section (MAC) of 10.9±2.1 m212 /g at 660 nm (or 13.1 m213 /g @ 550 nm, assuming MAC is inversely dependent on wavelength). This appears independent of aging and similar to the expected absorption cross-section for aged BC, but values, particularly in fresh emissions, could be biased high due to instrument artifacts. SP2-derived BC coating indicators show a prominent thinly-coated BC mode over the Mexico City Metropolitan Area (MCMA), while older air masses show both thinly-coated and thickly-coated BC. Some 2-day-old plumes do not show a prominent thickly-coated BC mode, possibly due to preferential wet scavenging of the likely-hydrophilic thickly-coated BC.

  4. Black carbon over Mexico: the effect of atmospheric transport on mixing state, mass absorption cross-section, and BC/CO ratios

    NASA Astrophysics Data System (ADS)

    Subramanian, R.; Kok, G. L.; Baumgardner, D.; Clarke, A.; Shinozuka, Y.; Campos, T. L.; Heizer, C. G.; Stephens, B. B.; de Foy, B.; Voss, P. B.; Zaveri, R. A.

    2010-01-01

    A single particle soot photometer (SP2) was operated on the NCAR C-130 during the MIRAGE campaign (part of MILAGRO), sampling black carbon (BC) over Mexico. The highest BC concentrations were measured over Mexico City (sometimes as much as 2 μg/m3) and over hill-fires to the south of the city. The age of plumes outside of Mexico City was determined using a combination of HYSPLIT trajectories, WRF-FLEXPART modeling and CMET balloon tracks. As expected, older, diluted air masses had lower BC concentrations. A comparison of carbon monoxide (CO) and BC suggests a CO background of around 65 ppbv, and a background-corrected BC/COnet ratio of 2.89±0.89 (ng/m3-STP)/ppbv (average ± standard deviation). This ratio is similar for fresh emissions over Mexico City, as well as for aged airmasses. Comparison of light absorption measured with a particle soot absorption photometer (PSAP) and the SP2 BC suggests a BC mass-normalized absorption cross-section (MAC) of 10.9±2.1 m2/g at 660 nm (or 13.1 m2/g @ 550 nm, assuming MAC is inversely dependent on wavelength). This appears independent of aging and similar to the expected absorption cross-section for aged BC, but values, particularly in fresh emissions, could be biased high due to instrument artifacts. SP2-derived BC coating indicators show a prominent thinly-coated BC mode over the Mexico City Metropolitan Area (MCMA), while older air masses show both thinly-coated and thickly-coated BC. Some 2-day-old plumes do not show a prominent thickly-coated BC mode, possibly due to preferential wet scavenging of the likely-hydrophilic thickly-coated BC.

  5. Complex angular momentum theory of state-to-state integral cross sections: resonance effects in the F + HD → HF(v' = 3) + D reaction.

    PubMed

    Sokolovski, D; Akhmatskaya, E; Echeverría-Arrondo, C; De Fazio, D

    2015-07-28

    State-to-state reactive integral cross sections (ICSs) are often affected by quantum mechanical resonances, especially near a reactive threshold. An ICS is usually obtained by summing partial waves at a given value of energy. For this reason, the knowledge of pole positions and residues in the complex energy plane is not sufficient for a quantitative description of the patterns produced by resonance. Such description is available in terms of the poles of an S-matrix element in the complex plane of the total angular momentum. The approach was recently implemented in a computer code ICS_Regge, available in the public domain [Comput. Phys. Commun., 2014, 185, 2127]. In this paper, we employ the ICS_Regge package to analyse in detail, for the first time, the resonance patterns predicted for integral cross sections (ICSs) of the benchmark F + HD → HF(v' = 3) + D reaction. The v = 0, j = 0, Ω = 0 → v' = 3, j' = 0, 1, 2, and Ω' = 0, 1, 2 transitions are studied for collision energies from 58.54 to 197.54 meV. For these energies, we find several resonances, whose contributions to the ICS vary from symmetric and asymmetric Fano shapes to smooth sinusoidal Regge oscillations. Complex energies of metastable states and Regge pole positions and residues are found by Padé reconstruction of the scattering matrix elements. The accuracy of the ICS_Regge code, relation between complex energies and Regge poles, various types of Regge trajectories, and the origin of the J-shifting approximation are also discussed.

  6. Handbook of LHC Higgs Cross Sections: 4. Deciphering the Nature of the Higgs Sector

    SciTech Connect

    de Florian, D.

    2016-10-25

    This Report summarizes the results of the activities of the LHC Higgs Cross Section Working Group in the period 2014-2016. The main goal of the working group was to present the state-of-the-art of Higgs physics at the LHC, integrating all new results that have appeared in the last few years. The first part compiles the most up-to-date predictions of Higgs boson production cross sections and decay branching ratios, parton distribution functions, and off-shell Higgs boson production and interference effects. The second part discusses the recent progress in Higgs effective field theory predictions, followed by the third part on pseudo-observables, simplified template cross section and fiducial cross section measurements, which give the baseline framework for Higgs boson property measurements. The fourth part deals with the beyond the Standard Model predictions of various benchmark scenarios of Minimal Supersymmetric Standard Model, extended scalar sector, Next-to-Minimal Supersymmetric Standard Model and exotic Higgs boson decays. This report follows three previous working-group reports: Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002), Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002), and Handbook of LHC Higgs Cross Sections: 3. Higgs properties (CERN-2013-004). The current report serves as the baseline reference for Higgs physics in LHC Run 2 and beyond.

  7. Thermal neutron capture cross sections of the potassium isotopes

    NASA Astrophysics Data System (ADS)

    Firestone, R. B.; Krtička, M.; Révay, Zs.; Szentmiklosi, L.; Belgya, T.

    2013-02-01

    Precise thermal neutron capture γ-ray cross sections σγ for 39,40,41K were measured on a natural potassium target with the guided neutron beam at the Budapest Reactor. The cross sections were internally standardized using a stoichiometric KCl target with well-known 35Cl(n,γ) γ-ray cross sections [Révay and Molnár, Radiochimica ActaRAACAP0033-823010.1524/ract.91.6.361.20027 91, 361 (2003); Molnár, Révay, and Belgya, Nucl. Instrum. Meth. Phys. Res. BNIMBEU0168-583X10.1016/S0168-583X(03)01529-5 213, 32 (2004)]. These data were combined with γ-ray intensities from von Egidy [von Egidy, Daniel, Hungerford, Schmidt, Lieb, Krusche, Kerr, Barreau, Borner, Brissot , J. Phys. G. Nucl. Phys.JPHGBM0305-461610.1088/0305-4616/10/2/013 10, 221 (1984)] and Krusche [Krusche, Lieb, Ziegler, Daniel, von Egidy, Rascher, Barreau, Borner, and Warner, Nucl. Phys. ANUPABL0375-947410.1016/0375-9474(84)90506-2 417, 231 (1984); Krusche, Winter, Lieb, Hungerford, Schmidt, von Egidy, Scheerer, Kerr, and Borner, Nucl. Phys. ANUPABL0375-947410.1016/0375-9474(85)90429-4 439, 219 (1985)] to generate nearly complete capture γ-ray level schemes. Total radiative neutron cross sections were deduced from the total γ-ray cross section feeding the ground state, σ0=Σσγ(GS) after correction for unobserved statistical γ-ray feeding from levels near the neutron capture energy. The corrections were performed with Monte Carlo simulations of the potassium thermal neutron capture decay schemes using the computer code dicebox where the simulated populations of low-lying levels are normalized to the measured cross section depopulating those levels. Comparisons of the simulated and experimental level feeding intensities have led to proposed new spins and parities for selected levels in the potassium isotopes where direct reactions are not a significant contribution. We determined the total radiative neutron cross sections σ0(39K)=2.28±0.04 b, σ0(40K)=90±7 b, and σ0(41K)=1.62±0.03 b from the

  8. Average cross section measurement for 162Er (γ, n) reaction compared with theoretical calculations using TALYS

    NASA Astrophysics Data System (ADS)

    Vagena, E.; Stoulos, S.

    2017-01-01

    Bremsstrahlung photon beam delivered by a linear electron accelerator has been used to experimentally determine the near threshold photonuclear cross section data of nuclides. For the first time, (γ, n) cross section data was obtained for the astrophysical important nucleus 162Er. Moreover, theoretical calculations have been applied using the TALYS 1.6 code. The effect of the gamma ray strength function on the cross section calculations has been studied. A satisfactorily reproduction of the available experimental data of photonuclear cross section at the energy region below 20 MeV could be achieved. The photon flux was monitored by measuring the photons yield from seven well known (γ, n) reactions from the threshold energy of each reaction up to the end-point energy of the photon beam used. An integrated cross-section 87 ± 14 mb is calculated for the photonuclear reaction 162Er (γ, n) at the energy 9.2-14 MeV. The effective cross section estimated using the TALYS code range between 89 and 96 mb depending on the γ-strength function used. To validate the method for the estimation of the average cross-section data of 162Er (γ, n) reaction, the same procedure has been performed to calculate the average cross-section data of 197Au (γ, n) and 55Mn (γ, n) reactions. In this case, the photons yield from the rest well known (γ, n) reactions was used in order to monitoring the photon flux. The results for 162Er (γ, n), 197Au (γ, n) and 55Mn (γ, n) are found to be in good agreement with the theoretical values obtained by TALYS 1.6. So, the present indirect process could be a valuable tool to estimate the effective cross section of (γ, n) reaction for various isotopes using bremsstrahlung beams.

  9. 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.

  10. Profile variation impact on FIB cross-section metrology

    NASA Astrophysics Data System (ADS)

    Cordes, Aaron; Bunday, Benjamin; Nadeau, Jim

    2012-03-01

    The focused ion beam (FIB) milling tool is an important component of reference metrology and process characterization, both as a supporting instrument for bulk sample preparation before forwarding to the transmission electron microscope (TEM) and other instruments and as an in situ measurement instrument using angled scanning electron microscopy. As features grow denser, deeper and more demanding, full-profile reference metrology is needed, and this methodology will only grow in importance. Thus, the ability to extract accurate dimensional and profile information out of the crosssectional faces produced by FIB milling is critical. For features that demonstrate perfect symmetry in the plane of the cross section, analyzing images and extracting metrology data are straightforward. However, for industrial materials, symmetry is not a safe assumption: as features shrink, the line edge and sidewall roughness increases as a percentage of the overall feature dimension. Furthermore, with the introduction of more complex architectures such as 3D memory and FinFETs, the areas of greatest interest, such as the intersections of wrap-around gates, cannot be assumed to be symmetrical in any given plane if cut placement is not precisely controlled. Therefore it is important to establish the exact location and repeatability of the cross-section plane, both in terms of coordinate placement and effective angle of the milled surface. To this end, we prepared designed-in line edge roughness samples in the Albany Nanotech facility using SEMATECH's AMAG6 metrology reticle. The samples were thoroughly characterized before being milled by a non-destructive, sidewall-scanning atomic force microscope (AFM). These samples are then milled and measured under varying process and setup parameters using a single-beam FIB with angled SEM. We established methodologies that allow precise alignment of the cut planes of slice-and-view FIB milling to 3D-AFM scan lines to compare repeated sections

  11. Turbulent combustion flow through variable cross section channel

    SciTech Connect

    Rogov, B.V.; Sokolova, I.A.

    1999-07-01

    The object of this study is to develop a new evolutionary numerical method for solving direct task of Laval nozzle, which provides non-iterative calculations of chemical reacting turbulent flows with detailed kinetic chemistry. The numerical scheme of fourth order along the normal coordinate and second order along the streamwise one is derived for calculation of difference-differential equations of the second order and the first order. Marching method provides the possibility of computing field flow in subsonic section of nozzle and near an expansion. Critical mass consumption is calculated with controlled accuracy. After critical cross section of nozzle a combined marching method with global iterations over axial pressure (only) makes it possible to overcome ill posedness of mixed supersonic flow and calculate the whole flow field near and after critical cross section. Numerical results are demonstrated on turbulent burning hydrogen-oxygen flow through Laval nozzle with curvature of wall K{sub w} = 0.5.

  12. Modeling plasma-based CO2 conversion: crucial role of the dissociation cross section

    NASA Astrophysics Data System (ADS)

    Bogaerts, Annemie; Wang, Weizong; Berthelot, Antonin; Guerra, Vasco

    2016-10-01

    Plasma-based CO2 conversion is gaining increasing interest worldwide. A large research effort is devoted to improving the energy efficiency. For this purpose, it is very important to understand the underlying mechanisms of the CO2 conversion. The latter can be obtained by computer modeling, describing in detail the behavior of the various plasma species and all relevant chemical processes. However, the accuracy of the modeling results critically depends on the accuracy of the assumed input data, like cross sections. This is especially true for the cross section of electron impact dissociation, as the latter process is believed to proceed through electron impact excitation, but it is not clear from the literature which excitation channels effectively lead to dissociation. Therefore, the present paper discusses the effect of different electron impact dissociation cross sections reported in the literature on the calculated CO2 conversion, for a dielectric barrier discharge (DBD) and a microwave (MW) plasma. Comparison is made to experimental data for the DBD case, to elucidate which cross section might be the most realistic. This comparison reveals that the cross sections proposed by Itikawa and by Polak and Slovetsky both seem to underestimate the CO2 conversion. The cross sections recommended by Phelps with thresholds of 7 eV and 10.5 eV yield a CO2 conversion only slightly lower than the experimental data, but the sum of both cross sections overestimates the values, indicating that these cross sections represent dissociation, but most probably also include other (pure excitation) channels. Our calculations indicate that the choice of the electron impact dissociation cross section is crucial for the DBD, where this process is the dominant mechanism for CO2 conversion. In the MW plasma, it is only significant at pressures up to 100 mbar, while it is of minor importance for higher pressures, when dissociation proceeds mainly through collisions of CO2 with heavy

  13. GIS-based data model and tools for creating and managing two-dimensional cross sections

    NASA Astrophysics Data System (ADS)

    Whiteaker, Timothy L.; Jones, Norm; Strassberg, Gil; Lemon, Alan; Gallup, Doug

    2012-02-01

    While modern Geographic Information Systems (GIS) software is robust in handling maps and data in plan view, the software generally falls short when representing features in section view. Further complicating the issue is the fact that geologic cross sections are often drawn by connecting a series of wells together that do not fall along a single straight line. In this case, the x-axis of the cross section represents the distance along the set of individual lines connecting the series of wells, effectively "flattening out" the cross section along this path to create a view of the subsurface with which geologists often work in printed folios. Even 3D-enabled GIS cannot handle this type of cross section. A GIS data model and tools for creating and working with two-dimensional cross sections are presented. The data model and tools create a framework that can be applied using ESRI's ArcGIS software, enabling users to create, edit, manage, and print two-dimensional cross sections from within one of the most well-known GIS software packages. The data model is a component of the arc hydro groundwater data model, which means all two-dimensional cross sections are inherently linked to other features in the hydrogeologic domain, including those represented by xyz coordinates in real world space. Thus, the creation of two-dimensional cross sections can be guided by or completely driven from standard GIS data, and geologic interpretations established on two-dimensional cross sections can be translated back to real world coordinates to create three-dimensional features such as fence diagrams, giving GIS users the capacity to characterize the subsurface environment in a variety of integrated views that was not possible before. A case study for the Sacramento Regional Model in California demonstrates the application of the methodology in support of a regional groundwater management plan.

  14. Positronium Formation Cross-Sections for Positron Scattering by Rubidium Atoms

    NASA Astrophysics Data System (ADS)

    El-Bakry, Salah Yaseen

    Cross-sections for positron-rubidium (37Rb) scattering have been calculated using the Clementi-Roetti wavefunctions and a combination of the coupled-static and frozen-core approximations. The total cross-sections, calculated with eight partial waves corresponding to the total angular momentum ℓ=0 to ℓ=7, are determined over a wide region of scattering energies ranging from 2.7 to 300 eV. The resulting total cross-sections are compared with experimental results and those calculated by other authors. Our total collisional cross-sections display a pronounced peak at 5 eV, nearly consistent with the measurements of Parikh et al. [Phys. Rev. A 47, 1535 (1993)] and also reveal another peak at 7 eV, consistent with the experimental cross-section of Stein et al.23 in the neighborhood of 7 eV. The oscillating behavior of our total collisional cross-sections supports the possible existence of resonance, especially at low energy region. The effect of positronium formation on the total collisional cross-sections diminishes when the incident energy is larger than 100 eV.

  15. The total, elastic and inelastic scattering fast neutron cross sections of natural chromium

    SciTech Connect

    Guenther, P.T.; Smith, J.F.; Whalen, A.B.

    1982-12-01

    The present experimental results comprise a comprehensive intermediate resolution neutron total and scattering cross-section data base for elemental chromium over the energy range from 1.5 to 4.0 MeV. Nonetheless, due to the fluctuating nature of the cross sections involved, the definition of energy-averaged cross sections is uncertain. The consequences of these energy-dependent fluctuations and attendant complications influence the data analysis and interpretation. All finite sample total crosssection measurements result in effective cross sections that have to be corrected to yield the true energyaveraged cross sections. This was accomplished by concurrent multiple sample thickness measurements the results of which were then linearly extrapolated to the zero thickness cross section. It was noted that the resulting sample thickness correction showed marked local fluctuations necessitating an energy by energy treatment. Furthermore, the cross sections, even after averaging over wide energy intervals, retained undulations that complicated comparisons with model calculations. Quantitative comparisons of the present elastic and inelastic scattering results with those obtained at isolated energies by other authors were difficult, if not deceptive, due to persistent fluctuations.

  16. O2 absorption cross sections /187-225 nm/ from stratospheric solar flux measurements

    NASA Astrophysics Data System (ADS)

    Herman, J. R.; Mentall, J. E.

    1982-10-01

    The absorption cross sections of molecular oxygen are calculated in the wavelength range from 187 to 230 nm from solar flux measurements obtained within the stratosphere. Within the Herzberg continuum wavelength region the molecular oxygen cross sections are found to be about 30% smaller than the laboratory results of Shardanand and Rao (1977) from 200 to 210 nm and about 50% smaller than those of Hasson and Nicholls (1971). At wavelengths longer than 210 nm the cross sections agree with those of Shardanand and Rao. The effective absorption cross sections of O2 in the Schumann-Runge band region from 187 to 200 nm are calculated and compared to the empirical fit given by Allen and Frederick (1982). The calculated cross sections indicate that the transmissivity of the atmosphere may be underestimated by the use of the Allen and Frederic cross sections between 195 and 200 nm. The ozone column content between 30 and 40 km and the relative ozone cross sections are determined from the same solar flux data set.

  17. O2 absorption cross sections /187-225 nm/ from stratospheric solar flux measurements

    NASA Technical Reports Server (NTRS)

    Herman, J. R.; Mentall, J. E.

    1982-01-01

    The absorption cross sections of molecular oxygen are calculated in the wavelength range from 187 to 230 nm from solar flux measurements obtained within the stratosphere. Within the Herzberg continuum wavelength region the molecular oxygen cross sections are found to be about 30% smaller than the laboratory results of Shardanand and Rao (1977) from 200 to 210 nm and about 50% smaller than those of Hasson and Nicholls (1971). At wavelengths longer than 210 nm the cross sections agree with those of Shardanand and Rao. The effective absorption cross sections of O2 in the Schumann-Runge band region from 187 to 200 nm are calculated and compared to the empirical fit given by Allen and Frederick (1982). The calculated cross sections indicate that the transmissivity of the atmosphere may be underestimated by the use of the Allen and Frederic cross sections between 195 and 200 nm. The ozone column content between 30 and 40 km and the relative ozone cross sections are determined from the same solar flux data set.

  18. Measurement of electron impact collisional excitation cross sections of Ni to Ge-like gold

    NASA Astrophysics Data System (ADS)

    May, M. J.; Beiersdorfer, P.; Jordan, N.; Scofield, J. H.; Reed, K. J.; Brown, G. V.; Hansen, S. B.; Porter, F. S.; Kelley, R.; Kilbourne, C. A.; Boyce, K. R.

    2017-03-01

    We have measured the collisional excitation cross sections for the 3d→4f and 3d→5f excitations in Au ions near the Ni-like charge state by using beam plasmas created in the Livermore electron beam ion trap EBIT-I. The cross sections have been experimentally determined at approximately 1, 2 and 3 keV above the threshold energy, ET, for the 3d→4f excitations (ET ˜ 2.5 keV) and at approximately 0.1, 1 and 2 keV above the threshold energy for the 3d→5f excitations (ET ˜ 3.3 keV). The cross section measurements were made possible by using the GSFC x-ray microcalorimeter at the Livermore EBIT facility. The absolute cross sections are determined from the ratio of the intensity of the collisionally excited bound-bound transitions to the intensity of the radiative recombination lines produced in EBIT-I plasmas. The effects of polarization and Auger decay channels are accounted for in the cross section determination. Measured cross sections are compared with those from HULLAC, DWS and FAC calculations. The measurements demonstrate that some errors exist in the calculated excitation cross sections.

  19. Ice Layer Cross-Section In False Color

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.

    This image of shows a cross sectional view of the ice layers. Note the subtle peach banding on the left side of the image. The time variation that the bands represent is not yet understood.

    Image information: VIS instrument. Latitude 83.5, Longitude 118.2 East (241.8 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. Differential Photoproduction Cross Sections of the Sigma0(1385), Lambda(1405), and Lambda(1520)

    SciTech Connect

    Moriya, Kei; Schumacher, Reinhard A.

    2013-10-01

    We report the exclusive photoproduction cross sections for the Sigma(1385), Lambda(1405), and Lambda(1520) in the reactions gamma + p -> K+ + Y* using the CLAS detector for energies from near the respective production thresholds up to a center-of-mass energy W of 2.85 GeV. The differential cross sections are integrated to give the total exclusive cross sections for each hyperon. Comparisons are made to current theoretical models based on the effective Lagrangian approach and fitted to previous data. The accuracy of these models is seen to vary widely. The cross sections for the Lambda(1405) region are strikingly different for the Sigma+pi-, Sigma0 pi0, and Sigma- pi+ decay channels, indicating the effect of isospin interference, especially at W values close to the threshold.