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Sample records for central diffractive heavy

  1. Central diffraction at ALICE

    NASA Astrophysics Data System (ADS)

    Lämsä, J. W.; Orava, R.

    2011-02-01

    The ALICE experiment is shown to be well suited for studies of exclusive final states from central diffractive reactions. The gluon-rich environment of the central system allows detailed QCD studies and searches for exotic meson states, such as glueballs, hybrids and new charmonium-like states. It would also provide a good testing ground for detailed studies of heavy quarkonia. Due to its central barrel performance, ALICE can accurately measure the low-mass central systems with good purity. The efficiency of the Forward Multiplicity Detector (FMD) and the Forward Shower Counter (FSC) system for detecting rapidity gaps is shown to be adequate for the proposed studies. With this detector arrangement, valuable new data can be obtained by tagging central diffractive processes.

  2. Central Diffraction in ALICE

    SciTech Connect

    Schicker, R.

    2011-07-15

    The ALICE experiment consists of a central barrel in the pseudorapidity range -0.9<{eta}<0.9 and of additional detectors covering about 3 units of pseudorapidity on either side of the central barrel. Such a geometry allows the tagging of single and double gap events. The status of the analysis of such diffractive events in proton-proton collisions at {radical}(s) = 7 TeV is presented.

  3. Diffraction and central exclusive production at ATLAS

    SciTech Connect

    Tasevsky, Marek

    2011-07-15

    The diffractive physics program for the ATLAS experiment with an emphasis on the central exclusive production is discussed. The key point in this discussion is the need for an unambiguous experimental definition of diffractive signature which would be acceptable and reproducible by theorists. Recent ATLAS results from samples enhanced in diffraction contribution underline this need.

  4. Central collisions of heavy ions

    SciTech Connect

    Fung, Sun-yiu.

    1992-10-01

    This report describes the activities of the Heavy Ion Physics Group at the University of California, Riverside from October 1, 1991 to September 30, 1992. During this period, the program focused on particle production at AGS energies, and correlation studies at the Bevalac in nucleus-nucleus central collisions. As part of the PHENIX collaboration, contributions were made to the Preliminary Conceptual Design Report (pCDR), and work on a RHIC silicon microstrip detector R D project was performed.

  5. Diffraction phenomena in elastic scattering of heavy ions

    SciTech Connect

    Kotlyar, V.V.; Shebeko, A.V.

    1981-08-01

    Nuclear diffraction phenomena in elastic scattering of heavy ions are studied in the intermediate energy range. Examination is carried out using the strong absorption models for the S-matrix in the angular momentum representation. New asymptotic expressions for the diffraction scattering amplitudes are obtained. The main attention is paid to the study of the relation between the Fresnel and the Fraunhofer parts of the amplitudes obtained in different regions of scattering angles.

  6. Communication: Heavy atom quantum diffraction by scattering from surfaces.

    PubMed

    Moix, Jeremy M; Pollak, Eli

    2011-01-07

    Typically one expects that when a heavy particle collides with a surface, the scattered angular distribution will follow classical mechanics. The heavy mass usually assures that the coherence length of the incident particle in the direction of the propagation of the particle (the parallel direction) will be much shorter than the characteristic lattice length of the surface, thus leading to a classical description. Recent work on molecular interferometry has shown that extreme collimation of the beam creates a perpendicular coherence length which is sufficiently long so as to observe interference of very heavy species passing through a grating. Here we show, using quantum mechanical simulations, that the same effect will lead to quantum diffraction of heavy particles colliding with a surface. The effect is robust with respect to the incident energy, the angle of incidence, and the mass of the particle.

  7. Diffractive production of heavy mesons at the LHC

    NASA Astrophysics Data System (ADS)

    Łuszczak, Marta; Szczurek, Antoni

    2016-11-01

    We discuss diffractive production of heavy mesons at the LHC. In addition to standard collinear approach, for a first time we propose a kt-factorization approach to the diffractive processes. The unintegrated (transverse momentum dependent) diffractive parton distributions in proton are calculated with the help of the Kimber-Martin-Ryskin prescription where collinear diffractive PDFs are used as input. Some correlation observables, like azimuthal angle correlation between c and c¯, and cc¯ pair transverse momentum distribution were obtained for the first time. The results of the new approach are compared with those of the standard collinear one. Significantly larger cross sections are obtained in the kt-factorization approach where some part of higher-order effects is effectively included.

  8. Diffractive Higgs Production from Intrinsic Heavy Flavors in the Proton

    SciTech Connect

    Brodsky, Stanley J.; Kopeliovich, Boris; Schmidt, Ivan; Soffer, Jacques

    2006-03-31

    We propose a novel mechanism for exclusive diffractive Higgs production pp {yields} pHp in which the Higgs boson carries a significant fraction of the projectile proton momentum. This mechanism will provide a clear experimental signal for Higgs production due to the small background in this kinematic region. The key assumption underlying our analysis is the presence of intrinsic heavy flavor components of the proton bound state, whose existence at high light-cone momentum fraction x has growing experimental and theoretical support. We also discuss the implications of this picture for exclusive diffractive quarkonium and other channels.

  9. Estimate of the single diffractive heavy quark production in heavy ion collisions at the CERN LHC

    SciTech Connect

    Gay Ducati, M. B.; Machado, M. M.; Machado, M. V. T.

    2010-03-01

    The single diffractive cross section for heavy quarks production is calculated at next-to-leading order (for nucleus-nucleus collisions. Such processes are expected to occur at the LHC, where the nuclei involved are lead at {radical}(s)=5.5 TeV and calcium at {radical}(s)=6.3 TeV. We start using the hard diffractive factorization formalism, taking into account a recent experimental parametrization for the Pomeron structure function (DPDF). Absorptive corrections are accounted for by the multiple Pomeron contributions considering a gap survival probability, where its theoretical uncertainty for nuclear collisions is discussed. We estimate the diffractive ratios for the single diffraction process in nuclear coherent/incoherent collisions at the LHC.

  10. Central diffractive resonance production at the LHC

    NASA Astrophysics Data System (ADS)

    Fiore, Roberto; Jenkovszky, Laszlo; Schicker, Rainer

    2016-07-01

    Central production of resonances resulting from the scattering of Pomerons in the central rapidity region of proton-proton scattering is studied. Estimates for relevant cross sections are presented. L.J. gratefully acknowledges an EMMI visiting Professorship at the University of Heidelberg for completion of this work. He is grateful to the organizers of this meeting for their hospitality and support. His work was supported also by DOMUS, Hungarian Academy of Sciences

  11. Microbial diffraction gratings as optical detectors for heavy metal pollutants

    NASA Astrophysics Data System (ADS)

    Noever, David; Matsos, Helen; Brittain, Andrew; Obenhuber, Don; Cronise, Raymond; Armstrong, Shannon

    1996-03-01

    As a significant industrial pollutant, cadmium is implicated as the cause of itai-itai disease. For biological detection of cadmium toxicity, an assay device has been developed using the motile response of the protozoa species, Tetrahymena pyriformis. This mobile protozoa measures 50 μm in diameter, swims at 10 body lengths per second, and aggregates into macroscopically visible patterns at high organism concentrations. The assay demonstrates a Cd+2 sensitivity better than 1 μM and a toxicity threshold to 5 μM, thus encouraging the study of these microbial cultures as viable pollution detectors. Using two-dimensional diffraction patterns within a Tetrahymena culture, the scattered light intensity varies with different organism densities (population counts). The resulting density profile correlates strongly with the toxic effects at very low dosages for cadmium (<5 ppm) and then for poison protection directly (with nickel and copper antagonists competing with cadmium absorption). In particular, copper dosages as low as 0.1-0.5 mM Cu have shown protective antagonism against cadmium, have enhanced density variability for cultures containing 1 mM Cd+2, and therefore have demonstrated the sensitivity of the optical detection system. In this way, such microbial diffraction patterns give a responsive optical measure of biological culture changes and toxicity determination in aqueous samples of heavy metals and industrial pollutants.

  12. Microbial Diffraction Gratings as Optical Detectors for Heavy Metal Pollutants

    NASA Technical Reports Server (NTRS)

    Noever, David; Matsos, Helen; Brittain, Andrew; Obenhuber, Don; Cronise, Raymond; Armstrong, Shannon

    1996-01-01

    As a significant industrial pollutant, cadmium is implicated as the cause of itai-itai disease. For biological detection of cadmium toxicity, an assay device has been developed using the motile response of the protozoa species, Tetrahymena pyriformis. This mobile protozoa measures 50 microns in diameter, swims at 10 body lengths per second, and aggregates into macroscopically visible patterns at high organism concentrations. The assay demonstrates a Cd(+2) sensitivity better than 1 micro-M and a toxicity threshold to 5 micro-M, thus encouraging the study of these microbial cultures as viable pollution detectors. Using two-dimensional diffraction patterns within a Tetrahymena culture, the scattered light intensity varies with different organism densities (population counts). The resulting density profile correlates strongly with the toxic effects at very low dosages for cadmium (less than 5 ppm) and then for poison protection directly (with nickel and copper antagonists competing with cadmium absorption). In particular, copper dosages as low as 0.1-0.5 mM Cu have shown protective antagonism against cadmium, have enhanced density variability for cultures containing 1 mM Cd(+2) and therefore have demonstrated the sensitivity of the optical detection system. In this way, such microbial diffraction patterns give a responsive optical measure of biological culture changes and toxicity determination in aqueous samples of heavy metals and industrial pollutants.

  13. Single and Central Diffractive Higgs Production at the LHC

    SciTech Connect

    Ducati, M. B. Gay; Machado, M. M.; Silveira, G. G.

    2011-07-15

    The single and central diffractive production of the Standard Model Higgs boson is computed using the diffractive factorization formalism, taking into account a parametrization for the Pomeron structure function provided by the H1 Collaboration. We compute the cross sections at NLO accuracy for the gluon fusion process, since it is the leading mechanism for the Higgs boson production. The gap survival probability is also introduced to include the rescattering corrections due to spectator particles present in the interaction. The diffractive ratios are predicted for proton-proton collisions at the LHC, since the beam luminosity is favorable to the Higgs boson detection. These results provide updated estimations for the fraction of single and central diffractive events in the LHC kinematical regime.

  14. Diffractive heavy flavor production-including W/sup +-/ and Z/sup 0/

    SciTech Connect

    White, A.R.

    1986-01-01

    It is shown that when the Pomeron has the semiperturbative origin in QCD, diffractive heavy quark production is independent from, and not suppressed relative to, the perturbative gluon fusion process. It is emphasized that anomalously large diffractive heavy flavor cross-sections could anticipate correspondingly large cross-sections for the diffractive production of W/sup +-/ and Z/sup 0/-providing distinctive evidence for the dynamical nature of the electroweak Higgs sector.

  15. Diffractive heavy quark production in AA collisions at the LHC at NLO

    SciTech Connect

    Machado, M. M.; Ducati, M. B. Gay; Machado, M. V. T.

    2011-07-15

    The single and double diffractive cross sections for heavy quarks production are evaluated at NLO accuracy for hadronic and heavy ion collisions at the LHC. Diffractive charm and bottom production is the main subject of this work, providing predictions for CaCa, PbPb and pPb collisions. The hard diffraction formalism is considered using the Ingelman-Schlein model where a recent parametrization for the Pomeron structure function (DPDF) is applied. Absorptive corrections are taken into account as well. The diffractive ratios are estimated and theoretical uncertainties are discussed. Comparison with competing production channels is also presented.

  16. Central Diffractive Processes at the Tevatron, RHIC and LHC

    SciTech Connect

    Harland-Lang, L. A.; Stirling, W. J.; Khoze, V. A.; Ryskin, M. G.

    2011-07-15

    Central exclusive production (CEP) processes in high-energy hadron collisions offer a very promising framework for studying both novel aspects of QCD and new physics signals. We report on the results of a theoretical study of the CEP of heavy quarkonia ({chi} and {eta}) at the Tevatron, RHIC and LHC (see for details [1]-[3]). These processes provide important information on the physics of bound states and can probe the current ideas and methods of QCD, such as effective field theories and lattice QCD.

  17. Exclusive central diffractive production of scalar, pseudoscalar and vector mesons

    NASA Astrophysics Data System (ADS)

    Lebiedowicz, P.; Nachtmann, O.; Szczurek, A.

    2014-11-01

    We discuss exclusive central diffractive production of scalar (ƒ0(980), ƒ0(1370), ƒ0(1500)), pseudoscalar (η, η'(958)), and vector (ρ0) mesons in proton-proton collisions. The amplitudes are formulated in terms of effective vertices required to respect standard rules of Quantum Field Theory and propagators for the exchanged pomeron and reggeons. Different pomeron-pomeron-meson tensorial (vectorial) coupling structures are possible in general. In most cases two lowest orbital angular momentum - spin couplings are necessary to describe experimental differential distributions. For the ƒ0(980) and η production the reggeon-pomeron, pomeron-reggeon, and reggeon-reggeon exchanges are included in addition, which seems to be necessary at relatively low energies. The theoretical results are compared with the WA102 experimental data, in order to determine the model parameters. For the ρ0 production the photon-pomeron and pomeron-photon exchanges are considered. The coupling parameters of tensor pomeron and/or reggeon are fixed from the H1 and ZEUS experimental data of the γp → ρ0 p reaction. We present first predictions of this mechanism for pp → ppπ+π- reaction being studied at COMPASS, RHIC, Tevatron, and LHC. Correlation in azimuthal angle between outgoing protons and distribution in pion rapidities at √s = 7 TeV are presented. We show that high-energy central production of mesons could provide crucial information on the spin structure of the soft pomeron.

  18. Hadron spectroscopy in diffractive and central production processes at COMPASS

    SciTech Connect

    Jasinski, Prometeusz Kryspin

    2011-07-15

    COMPASS is a fixed-target experiment using secondary high-energetic hadron beams provided by the CERN SPS. In 2008 and 2009, a large amount of data has been collected with a 190 GeV/c pion beam for the investigation of the hadron spectrum in diffractive and central production processes. A big variety of observed final states, including {pi}{sup -}{pi}{sup +}{pi}{sup -}, {pi}{sup -}{pi}{sup 0}{pi}{sup 0}, {pi}{sup -}{eta}{eta}, {pi}{sup -}K{sub s}K{sub s}, {pi}{sup -}K{sup +}K{sup -}, K{sup -}{pi}{sup +}{pi}{sup -}, and centrally produced 4{pi}, is being analysed. The potential for systematic spectroscopic studies especially concerning the existence and nature of spin-exotic, hybrid and glueball states is discussed. In addition, we show the first results from the data set collected with a proton beam in 2008. These data indicate the chance of COMPASS to contribute to the field of baryon spectroscopy.

  19. Magnetic structures of R(Cu, Ni)2 compounds (R = heavy rare earth) studied by neutron diffraction

    NASA Astrophysics Data System (ADS)

    Smetana, Z.; Šíma, V.

    1985-11-01

    Magnetics structures of powdered orthorhombic R(Cu, Ni)2 compounds (R = heavy rare earth) determined by neutron diffraction are described. The influence of magnetocrystalline anisotropy and exchange interactions on the type of magnetic ordering is discussed.

  20. Seasonal impact on beach morphology and the status of heavy mineral deposition - central Tamil Nadu coast, India

    NASA Astrophysics Data System (ADS)

    Joevivek, V.; Chandrasekar, N.

    2014-02-01

    The aim of the present research was to investigate the seasonal impact on nearshore beach dynamics and the status of heavy mineral distribution along central Tamil Nadu coast, India. Beach profile measurements were made in 10 profiling sites between Thirukadaiyur and Velankanni on monthly and seasonal basis from January 2011 to July 2012. Using beach profile data, variation in beach width, slope and volumetric changes have been calculated. Beach slope and nearshore wave parameters were used to quantify the longshore sediment transport rate. Beaches between Thirukadaiyur and Karaikkal attained predominant transport rate in northern direction whereas, the rest of the beaches are in southern direction. The seasonal action of wind and wave currents create nearshore bar during northeast (NE) monsoon and frequent berms at tidal zone during southwest (SW) monsoon. Surface sediment samples were collected in each location for quantifying the heavy mineral weight percentage during the period of pre- and post-Thane cyclone. Sediments were also studied by X-ray diffraction (XRD) to evaluate the changes and occurrence of heavy minerals in beach sands. The XRD results show that sediments in the study area have enriched heavy mineral distribution even after strong cyclonic event. It confirms the redistribution of heavy mineral deposits present in the coast. The results suggested that monsoonal action has influenced the seasonal changes in beach morphology and it does not affect the heavy mineral distribution.

  1. Residual Stress Analysis of Overspeeded Disk with Central Hole by X-ray Diffraction

    NASA Technical Reports Server (NTRS)

    Good, James N

    1948-01-01

    An X-ray - diffraction analysis of residual surface stresses after plastic strain was introduced in a parallel-sided 3S-O aluminum disk with a central hole by two types of centrifugal overspeed is reported. Both tangential and radial stresses were generally tensile with large local variations near the hole where surface stresses may have been partly superficial. These stresses were both tensile and compressive dependent on the distance from the disk center when mass compression was effected near the hole.

  2. Single-Crystal Neutron Diffraction Study of the Heavy-Electron Superconductor CeNiGe3

    NASA Astrophysics Data System (ADS)

    Ikeda, Yoichi; Ueta, Daichi; Yoshizawa, Hideki; Nakao, Akiko; Munakata, Koji; Ohhara, Takashi

    2015-12-01

    A single-crystal neutron diffraction study was performed on anomalous antiferromagnetic ordering in the heavy-electron superconductor CeNiGe3. We observed incommensurate magnetic Bragg reflections characterized by the incommensurate propagation vector k2 = (0,0.41,1/2) below the Néel temperature of 5 K, but no significant magnetic reflection with the commensurate propagation vector k1 = (1,0,0), at which another magnetic reflection was observed in a previous neutron diffraction study with a polycrystalline sample. From the single-crystal study, we suggest that the magnetic phase of CeNiGe3 at ambient pressure is characterized only by the incommensurate propagation vector k2.

  3. Online in situ x-ray diffraction setup for structural modification studies during swift heavy ion irradiation.

    PubMed

    Grygiel, C; Lebius, H; Bouffard, S; Quentin, A; Ramillon, J M; Madi, T; Guillous, S; Been, T; Guinement, P; Lelièvre, D; Monnet, I

    2012-01-01

    The high energy density of electronic excitations due to the impact of swift heavy ions can induce structural modifications in materials. We present an x-ray diffractometer called ALIX ("Analyse en Ligne sur IRRSUD par diffraction de rayons X"), which has been set up at the low-energy beamline (IRRadiation SUD - IRRSUD) of the Grand Accélérateur National d'Ions Lourds facility, to allow the study of structural modification kinetics as a function of the ion fluence. The x-ray setup has been modified and optimized to enable irradiation by swift heavy ions simultaneously to x-ray pattern recording. We present the capability of ALIX to perform simultaneous irradiation-diffraction by using energy discrimination between x-rays from diffraction and from ion-target interaction. To illustrate its potential, results of sequential or simultaneous irradiation-diffraction are presented in this article to show radiation effects on the structural properties of ceramics. Phase transition kinetics have been studied during xenon ion irradiation of polycrystalline MgO and SrTiO(3). We have observed that MgO oxide is radiation-resistant to high electronic excitations, contrary to the high sensitivity of SrTiO(3), which exhibits transition from the crystalline to the amorphous state during irradiation. By interpreting the amorphization kinetics of SrTiO(3), defect overlapping models are discussed as well as latent track characteristics. Together with a transmission electron microscopy study, we conclude that a single impact model describes the phase transition mechanism.

  4. Online in situ x-ray diffraction setup for structural modification studies during swift heavy ion irradiation

    NASA Astrophysics Data System (ADS)

    Grygiel, C.; Lebius, H.; Bouffard, S.; Quentin, A.; Ramillon, J. M.; Madi, T.; Guillous, S.; Been, T.; Guinement, P.; Lelièvre, D.; Monnet, I.

    2012-01-01

    The high energy density of electronic excitations due to the impact of swift heavy ions can induce structural modifications in materials. We present an x-ray diffractometer called ALIX ("Analyse en Ligne sur IRRSUD par diffraction de rayons X"), which has been set up at the low-energy beamline (IRRadiation SUD - IRRSUD) of the Grand Accélérateur National d'Ions Lourds facility, to allow the study of structural modification kinetics as a function of the ion fluence. The x-ray setup has been modified and optimized to enable irradiation by swift heavy ions simultaneously to x-ray pattern recording. We present the capability of ALIX to perform simultaneous irradiation-diffraction by using energy discrimination between x-rays from diffraction and from ion-target interaction. To illustrate its potential, results of sequential or simultaneous irradiation-diffraction are presented in this article to show radiation effects on the structural properties of ceramics. Phase transition kinetics have been studied during xenon ion irradiation of polycrystalline MgO and SrTiO3. We have observed that MgO oxide is radiation-resistant to high electronic excitations, contrary to the high sensitivity of SrTiO3, which exhibits transition from the crystalline to the amorphous state during irradiation. By interpreting the amorphization kinetics of SrTiO3, defect overlapping models are discussed as well as latent track characteristics. Together with a transmission electron microscopy study, we conclude that a single impact model describes the phase transition mechanism.

  5. X-ray diffraction studies of phase transformations in heavy-metal fluoride glasses

    NASA Technical Reports Server (NTRS)

    Bansal, N. P.; Doremus, R. H.

    1985-01-01

    Powder X-ray diffraction and differential scanning calorimetry studies of the crystallization properties of five ZrF4-based glass compositions have indicated that the crystalline phase in Zr-Ba-La-Pb fluoride glass is beta-BaZrF6; no such identification of crystal phases was obtainable, however, for the other glasses. Reversible polymorphic phase transformations occur in Zr-Ba-La-Li and Zr-Ba-La-Na fluoride glasses, upon heating to higher temperatures.

  6. X-ray diffraction studies of phase transformations in heavy-metal fluoride glasses

    NASA Technical Reports Server (NTRS)

    Bansal, N. P.; Doremus, R. H.

    1985-01-01

    Powder X-ray diffraction and differential scanning calorimetry studies of the crystallization properties of five ZrF4-based glass compositions have indicated that the crystalline phase in Zr-Ba-La-Pb fluoride glass is beta-BaZrF6; no such identification of crystal phases was obtainable, however, for the other glasses. Reversible polymorphic phase transformations occur in Zr-Ba-La-Li and Zr-Ba-La-Na fluoride glasses, upon heating to higher temperatures.

  7. Exclusive central diffractive production of scalar and pseudoscalar mesons; tensorial vs. vectorial pomeron

    SciTech Connect

    Lebiedowicz, Piotr; Nachtmann, Otto; Szczurek, Antoni

    2014-05-15

    We discuss consequences of the models of “tensorial pomeron” and “vectorial pomeron” for exclusive diffractive production of scalar and pseudoscalar mesons in proton–proton collisions. Diffractive production of f{sub 0}(980), f{sub 0}(1370), f{sub 0}(1500), η, and η{sup ′}(958) mesons is discussed. Different pomeron–pomeron–meson tensorial coupling structures are possible in general. In most cases two lowest orbital angular momentum–spin couplings are necessary to describe experimental differential distributions. For f{sub 0}(980) and η production reggeon–pomeron, pomeron–reggeon, and reggeon–reggeon exchanges are included in addition, which seems to be necessary at relatively low energies. The theoretical results are compared with the WA102 experimental data. Correlations in azimuthal angle between outgoing protons, distributions in rapidities and transverse momenta of outgoing protons and mesons, in a special “glueball filter variable”, as well as some two-dimensional distributions are presented. We discuss differences between results of the vectorial and tensorial pomeron models. We show that high-energy central production, in particular of pseudoscalar mesons, could provide crucial information on the spin structure of the soft pomeron.

  8. Masses and magnetic moments of heavy flavour baryons in the hyper central model

    NASA Astrophysics Data System (ADS)

    Patel, Bhavin; Rai, Ajay Kumar; Vinodkumar, P. C.

    2008-06-01

    Heavy flavour baryons containing one or two charm (beauty) quarks with light flavour combinations are studied using the hyper central description of the three-body system. The confinement potential is assumed as hyper central Coulomb plus power potential with a power index p. The ground state (J^P=\\frac{1}{2}^+ and \\frac{3}{2}^+ ) masses of heavy flavour baryons are computed for different power indices, p starting from 0.5 to 2.0. The predicted masses are found to attain a saturated value with respect to the variation in p beyond the power index p > 1.0. Using the spin-flavour structure of the constituting quarks and by defining the effective mass of the confined quarks within the baryons, the magnetic moments are computed with no additional free parameters. The masses and magnetic moments of the single heavy and double heavy flavour baryons are found to be in accordance with other model predictions.

  9. Characterization of Central Kalimantan’s Amethysts by Using X-Ray Diffraction

    NASA Astrophysics Data System (ADS)

    Gde Suastika, Komang; Yuwana, Lila; Hakim, Luqman; Darmaji; Khusnul, Didik

    2017-05-01

    X-Ray Diffraction (XRD) is one of spectroscopy method that utilize X-Ray as an energy source in the phases identification. This method is used to characterize the type of amethyst of Sukamara, Central Kalimantan. In this paper, the crystallography of three types of Sukamara amethyst is reported. Samples was collected directly from the amethyst mine in the Ajang village in the District of Permata Kecubung. The samples consists of three types i.e. purple amethyst, black amethyst, and violet amethyst. The results show that quartz or silica (SiO2) is the main phase of the gemstone amethyst. Amethyst cell parameters are a = b ≠ c and α = β ≠ γ, the crystal system is hexagonal. Amethyst average density is 2.65 g / cm3 and 112.84 pm3 cell volume. Peak FWHM value indicates that the degree of crystallinity of the black one is greater than that of the gasoline, while the degree of crystallinity of violet amethyst higher than purple amethyst.

  10. Heavy rainfall in future climate around the central Japan by pseudo global warming experiments

    NASA Astrophysics Data System (ADS)

    Taniguchi, K.

    2012-12-01

    The central part of Japan sometimes suffers from heavy rainfall derived by a typhoon. In 2000, a severe heavy rainfall attacked the central Japan. The maximum hourly precipitation in Aichi prefecture during this event was 114 mm, and daily precipitation 492 mm. On the other hand, it is reported that, in future climate, tropical cyclones (typhoons and hurricanes) will be stronger in IPCC AR4. In this study, variations in heavy rainfall around the central Japan are assessed by a pseudo global warming experiment using numerical weather prediction model. Based on the heavy rainfall event in 2000, pseudo global warming conditions are made from a reanalysis data and climate prediction in the 3rd phase of climate model intercomparison project (CMIP3), and simulations are made by the weather research forecasting model (WRF). The results of the control run of the heavy rainfall event in 2000 agree well with observed precipitation and same rainfall processes are found. In the pseudo global warming experiment using eight different CMIP3 output, five results show heavy rainfall around Aichi prefecture. Four results from the five heavy rainfalls show the larger maximum hourly precipitation, and the events continue longer than the control run. At the same time, using the same method, changes in precipitation characteristics around the central Japan are investigate for summer. The future climate conditions are obtained from dynamic downscaling by WRF using two pseudo global warming condition made with two CMIP3 projections (MPI ECHAM5 and CCCMA CGCM3.1 T47). The results show the opposite variation in future precipitation in the central Japan. In ECHAM5, summer precipitation increases in wide area, but the result with CCCMA shows decreasing precipitation especially in the Pacific side (see Figure). Such characteristics are found in the original CMIP3 output. Detail investigations of precipitation show that there are small variations in hourly precipitation in ECHAM5 and CCCMA

  11. High-resolution x-ray diffraction study of the heavy-fermion compound YbBiPt

    SciTech Connect

    Ueland, B. G.; Saunders, S. M.; Bud'ko, S. L.; Schmiedeshoff, G. M.; Canfield, P. C.; Kreyssig, A.; Goldman, A. I.

    2015-11-30

    In this study, YbBiPt is a heavy-fermion compound possessing significant short-range antiferromagnetic correlations below a temperature of T*=0.7K, fragile antiferromagnetic order below TN = 0.4K, a Kondo temperature of TK ≈ 1K, and crystalline-electric-field splitting on the order of E/kB = 1 – 10K. Whereas the compound has a face-centered-cubic lattice at ambient temperature, certain experimental data, particularly those from studies aimed at determining its crystalline-electric-field scheme, suggest that the lattice distorts at lower temperature. Here, we present results from high-resolution, high-energy x-ray diffraction experiments which show that, within our experimental resolution of ≈ 6 – 10 × 10–5 Å, no structural phase transition occurs between T = 1.5 and 50 K. In combination with results from dilatometry measurements, we further show that the compound's thermal expansion has a minimum at ≈ 18 K and a region of negative thermal expansion for 9 ≲ T ≲ 18 K. Despite diffraction patterns taken at 1.6 K which indicate that the lattice is face-centered cubic and that the Yb resides on a crystallographic site with cubic point symmetry, we demonstrate that the linear thermal expansion may be modeled using crystalline-electric-field level schemes appropriate for Yb3+ residing on a site with either cubic or less than cubic point symmetry.

  12. High-resolution x-ray diffraction study of the heavy-fermion compound YbBiPt

    DOE PAGES

    Ueland, B. G.; Saunders, S. M.; Bud'ko, S. L.; ...

    2015-11-30

    In this study, YbBiPt is a heavy-fermion compound possessing significant short-range antiferromagnetic correlations below a temperature of T*=0.7K, fragile antiferromagnetic order below TN = 0.4K, a Kondo temperature of TK ≈ 1K, and crystalline-electric-field splitting on the order of E/kB = 1 – 10K. Whereas the compound has a face-centered-cubic lattice at ambient temperature, certain experimental data, particularly those from studies aimed at determining its crystalline-electric-field scheme, suggest that the lattice distorts at lower temperature. Here, we present results from high-resolution, high-energy x-ray diffraction experiments which show that, within our experimental resolution of ≈ 6 – 10 × 10–5 Å,more » no structural phase transition occurs between T = 1.5 and 50 K. In combination with results from dilatometry measurements, we further show that the compound's thermal expansion has a minimum at ≈ 18 K and a region of negative thermal expansion for 9 ≲ T ≲ 18 K. Despite diffraction patterns taken at 1.6 K which indicate that the lattice is face-centered cubic and that the Yb resides on a crystallographic site with cubic point symmetry, we demonstrate that the linear thermal expansion may be modeled using crystalline-electric-field level schemes appropriate for Yb3+ residing on a site with either cubic or less than cubic point symmetry.« less

  13. Analysis of Soil Heavy Metal Pollution and Pattern in Central Transylvania

    PubMed Central

    Suciu, Ioan; Cosma, Constantin; Todică, Mihai; Bolboacă, Sorana D.; Jäntschi, Lorentz

    2008-01-01

    The concentration of five soil heavy metals (Pb, Co, Cr, Cu, Hg) was measured in forty sampling sites in central Transylvania, Romania, regions known as centres of pollution due to the chemical and metallurgical activities. The soil samples were collected from locations where the ground is not sliding and the probability of alluvial deposits is small. The concentration of heavy metals was measured by using the Inductively Coupled Plasma Spectrometry method. Data were verified by using the Neutron Activation Analysis method. In some locations, the concentration for the investigated heavy metals exceeds the concentration admitted by the Romanian guideline. The highest concentration of lead (1521.8 ppm) and copper (1197.6 ppm) was found in Zlatna. The highest concentration of chromium was found in Târnăveni (1080 ppm). The maximum admitted concentrations in the sensitive areas revealed to be exceed from five to forty times. PMID:19325760

  14. Central collisions of heavy ions. Progress report, October 1, 1991--September 31, 1992

    SciTech Connect

    Fung, Sun-yiu

    1992-10-01

    This report describes the activities of the Heavy Ion Physics Group at the University of California, Riverside from October 1, 1991 to September 30, 1992. During this period, the program focused on particle production at AGS energies, and correlation studies at the Bevalac in nucleus-nucleus central collisions. As part of the PHENIX collaboration, contributions were made to the Preliminary Conceptual Design Report (pCDR), and work on a RHIC silicon microstrip detector R&D project was performed.

  15. Central Limit Theorems for Linear Statistics of Heavy Tailed Random Matrices

    NASA Astrophysics Data System (ADS)

    Benaych-Georges, Florent; Guionnet, Alice; Male, Camille

    2014-07-01

    We show central limit theorems (CLT) for the linear statistics of symmetric matrices with independent heavy tailed entries, including entries in the domain of attraction of α-stable laws and entries with moments exploding with the dimension, as in the adjacency matrices of Erdös-Rényi graphs. For the second model, we also prove a central limit theorem of the moments of its empirical eigenvalues distribution. The limit laws are Gaussian, but unlike the case of standard Wigner matrices, the normalization is the one of the classical CLT for independent random variables.

  16. Tissue concentrations of heavy metals and polychlorinated biphenyls in raccoons in central New York

    SciTech Connect

    Valentine, R.L.; Bache, C.A.; Gutenmann, W.H.; Lisk, D.J. )

    1988-06-01

    The ubiquitous presence of heavy metals such as lead, mercury and cadmium and polychlorinated biphenyls (PCBs) in wildlife animals has been studied. Possible sources of these toxicants include pesticides used agriculturally, highway traffic exhaust, landfills, power plants and miscellaneous industrial and other activities. Fish-consuming animals may also absorb heavy metals and PCBs from this dietary source. Small game hunting and the trapping of fur-bearing animals are actively pursued in Central New York and these animals are exposed to all of the latter pollution sources. It was therefore of interest to determine the concentrations of such toxicants as cadmium, lead, mercury, selenium and PCBs in wildlife animals in this area of New York State.

  17. Electron backscattering diffraction analysis of an ancient wootz steel blade from central India

    SciTech Connect

    Barnett, M.R. Sullivan, A.; Balasubramaniam, R.

    2009-04-15

    The electron backscattering diffraction technique was used to analyse the nature of carbides present in an ancient wootz steel blade. Bulky carbides, pro-eutectoid carbide along the prior austenite grain boundaries and fine spheroidized carbides were detected. Electron backscattering diffraction was employed to understand the texture of these carbides. The orientations of the cementite frequently occur in clusters, which points to a common origin of the members of the cluster. For the bands of coarse cementite, the origin is probably large coarse particles formed during the original cooling of the wootz cake. Pearlite formed earlier in the forging process has led to groups of similarly oriented fine cementite particles. The crystallographic texture of the cementite is sharp whereas that of the ferrite is weak. The sharp cementite textures point to the longevity of the coarse cementite throughout the repeated forging steps and to the influence of existing textured cementite on the nucleation of new cementite during cooling.

  18. Centrality determination in heavy-ion collisions with the CBM experiment

    NASA Astrophysics Data System (ADS)

    Klochkov; Selyuzhenkov, I.; CBM collaboration

    2017-01-01

    The size and evolution of the medium created in a heavy-ion collision depends on collision geometry. Experimentally collisions can be characterized by the measured particle multiplicities around midrapidity or by the energy measured in the forward rapidity region, which is sensitive to the spectator fragments. In the Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) the multiplicity of produced particles is measured with the silicon tracking system (STS). The projectile spectator detector (PSD) measures the energy of spectator fragments. We present the procedure of collision centrality determination in CBM and its performance using the PSD and the STS information.

  19. Central collisions of heavy ions. Progress report, October 1, 1992--August 31, 1993

    SciTech Connect

    Fung, Sun-yiu

    1993-08-01

    This report describes the activities of the Heavy Ion Physics Group at the University of California, Riverside from October 1, 1992 to August 31, 1993. During this period, our AGS E802/E859/E866 experiments focused on strange particle production, and the fluctuation phenomenon associated with correlation studies in nucleus nucleus central collisions. We have designed and are implementing a new detector to replace the Target Multiplicity Array (TMA) for the E866 runs. As part of the PHENIX collaboration, we contributed to the Conceptual Design Report (CDR), and worked on a RHIC silicon microstrip detector R&D project, the central core of the multiplicity-vertex detector (MVD). In the coming year, we planned to complete the New Multiplicity Array (NMA) detector for the gold projectile E866 experiment, and analyzed the data associated with this new system. We are continuing our efforts in the preparation of the PHENIX detector system.

  20. Temporal distribution of heavy metal concentrations in oysters Crassostrea rhizophorae from the central Venezuelan coast.

    PubMed

    Alfonso, Juan A; Handt, Helga; Mora, Abrahan; Vásquez, Yaneth; Azocar, José; Marcano, Eunice

    2013-08-15

    The oyster Crassostrea rhizophorae is a bivalve abundant in Venezuelan estuaries and consumed by local populations. No known values have been reported on trace metals in oysters from the central Venezuelan coast. We report the concentrations of Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V and Zn in the soft parts of C. rhizophorae, which were collected bimonthly between March 2008 and March 2009, at two sampling areas from the Central Venezuelan Coast: Buche estuary and Mochima estuary. Our results show that for each metal there is a similar temporal variation pattern. The concentrations of the heavy metals reported in this work are useful as reliable baselines and can be used for comparison in future environment studies. Concentrations in C. rhizophorae from the Buche estuary can be interpreted to be high on a global scale for Cd, Cu, Ni and Mn, indicating atypically raised bioavailabilities.

  1. The environment quality of heavy metals in sediments from the central Bohai Sea.

    PubMed

    Liu, Ming; Zhang, Aibin; Liao, Yongjie; Chen, Bin; Fan, Dejiang

    2015-11-15

    The heavy metals (Cu, Co, Ni, Zn, Cr, Pb, Cd) in surface and core sediments from the central Bohai Sea were analyzed to evaluate the temporal/spatial distribution and pollution status. Cd exhibited gradual increase vertically, while others were stable or declined slightly in core sediments. In surface sediments, metals showed higher values in 'central mud area of the Bohai Sea' and the coastal area of the Bohai Bay. Cd and Pb also had high levels in the northeastern part of Bohai Sea. Both the contamination factors (CFs) and the geo-accumulation index (Igeo) indicated that Cu, Co, Ni, and Cr were not at pollution levels, while Pb, Zn, and Cd indicated moderate contamination. Compared with sediment quality guidelines (SQGs), Cu, Zn, Cr, Pb, and Cd were likely to produce occasional adverse biological effects, while Ni showed possible ecotoxicological risks. The combined levels of the metals have a 21% probability of being toxic.

  2. Neutron diffraction study of magnetic field induced behavior in the heavy Fermion Ce3Co4Sn13

    SciTech Connect

    Christianson, Andrew D; Goremychkin, E. A.; Gardner, J. S.; Kang, H. J.; Chung, J.-H.; Manuel, P.; Thompson, J. D.; Sarrao, J. L.; Lawrence, J. M.

    2008-01-01

    The specific heat of Ce3Co4Sn13 exhibits a crossover from heavy Fermion behavior with antiferromagnetic correlations at low field to single impurity Kondo behavior above 2 T. We have performed neutron diffraction measurements in magnetic fields up to 6 Tesla on single crystal samples. The (001) position shows a dramatic increase in intensity in field which appears to arise from static polarization of the 4f level and which at 0.14 K also exhibits an anomaly near 2T reflecting the crossover to single impurity behavior.

  3. Centrality dependence of strangeness enhancement in ultrarelativistic heavy ion collisions: A core-corona effect

    SciTech Connect

    Aichelin, J.; Werner, K.

    2009-06-15

    In ultrarelativistic heavy ion collisions, the multiplicity of multistrange baryons per participating nucleon increases with centrality in a different fashion for different systems and energies. At RHIC, for copper+copper (CuCu) collisions the increase is much steeper than for gold-gold (AuAu) collisions. We show that this system size dependence is due to a core-corona effect: the relative importance of the corona as compared to the core (thermalized matter) contribution varies and the contribution of a corona nucleon to the multiplicity differs from that of a core nucleon. {phi} mesons follow--as all hadrons--the same trend, but the difference between core and corona multiplicity is relatively small, and therefore the CuCu and AuAu results are quite similar. This simple geometrical explanation makes also a strong case in favor of the validity of Glauber geometry in the peripheral regions of ultrarelativistic heavy ion collisions, which is crucial for understanding the early evolution of the system.

  4. Assessment of heavy metal contamination and mineral magnetic characterization of the Asopos River sediments (Central Greece).

    PubMed

    Botsou, F; Karageorgis, A P; Dassenakis, E; Scoullos, M

    2011-03-01

    The content and distribution of heavy metals in sediments of the intermittent and contaminated Asopos River, located in Central Greece, was assessed by means of total dissolution, dilute acid and sequential extraction procedures. Mineral magnetic properties were used as proxy parameters of transport mechanisms of land-derived material to the sea. The combination of enrichment factors estimated against local background levels and the levels of labile metals revealed that surface sediments are enriched in Cu, Cd, Ni and Cr. The low flow of the system allows particles and organic matter to accumulate in the estuarine shallow "pools" where they undertake a series of redox reactions, authigenic formation, etc. The most fine of these particles, which are metal rich, are transported to relatively long distances off the Asopos River mouth, even under low energy conditions, converting the system to a secondary source of pollution for the adjacent marine environment.

  5. Central American Gyres, Tropical Cyclones, and Heavy Eastern U.S. Rainfall

    NASA Astrophysics Data System (ADS)

    Bosart, L. F.; Griffin, K. S.; Papin, P. P.; Torn, R. D.

    2012-12-01

    Between late summer and mid-autumn, broad low-level cyclonic circulations with spatial scales of 1000-2000 km can develop over Central America on time scales of 1-2 days and persist for 3-5 days. These broad cyclonic circulation regions, which hereafter we will call gyres, can absorb westward-moving tropical cyclones (TCs) from the east (e.g., Matthew in September 2010), disgorge cyclonic circulations to the northeast that later develop into TCs (e.g., Nicole in September 2010), interact with remnant southward-moving cold fronts to encourage weak TC development (e.g., TC Nate in October 2011), or enable weak eastern Pacific tropical depressions (TDs) to make landfall in Central America (e.g., TD 12-E in October 2011). A distinguishing feature of a Central American gyre is that it can be directly associated with exceptionally heavy rainfall and damaging regional flooding, such as occurred in conjunction with the landfall of TD 12-E and TC Nate. Similarly, a deep poleward tropical moisture transport from a Central American gyre in response to amplified midlatitude flow can lead to flooding rains in midlatitudes such as occurred along the Atlantic coast in conjunction with TC Lee in September 2011. This presentation will focus on the large-scale flow contribution to the formation of a well-defined Central American gyre in late September 2010 during the PREDICT field experiment and the subsequent impact of the gyre on the midlatitude flow and weather over eastern North America. The gyre formed when a strong east-west oriented cyclonic shear zone that separated anomalous tropical westerlies in the eastern Pacific from anomalous tropical easterlies over the Caribbean and North Atlantic was disrupted by northerly flow across the Isthmus of Tehuantepec gap (Chivela Pass) into the tropical Pacific. Initially, anomalous easterly flow from the Caribbean that was deflected southward by higher terrain to the west provided the initial source of northerly flow through the gap

  6. Photoproduction of vector mesons: from ultraperipheral to semi-central heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Kłusek-Gawenda, Mariola; Szczurek, Antoni

    2016-11-01

    We discuss nuclear cross sections for AA → AAV and AA → AAVV reactions with one or two vector mesons in the final state. Our analysis is done in the impact parameter space equivalent photon approximation. This approach allows to consider the above processes taking into account distance between colliding nuclei. We consider both ultraperipheral and semi-central collisions. We are a first group which undertook a study of single J/ψ photoproduction for different centrality bins. We show that one can describe new ALICE experimental data by including geometrical effects of collisions in the flux factor. Next, total and differential cross section for double-scattering mechanism in the exclusive AA → AAVV reaction in ultrarelativistic ultraperipheral heavy ion collisions is presented. In this context we consider double photoproduction and photon-photon processes. Simultaneously, we get very good agreement of our results with STAR (RHIC), CMS and ALICE (LHC) experimental data for single ρ0 and J/ψ vector meson production. A comparison of our predictions for exclusive four charged pions production is also presented.

  7. AD, the ALICE diffractive detector

    NASA Astrophysics Data System (ADS)

    Tello, Abraham Villatoro

    2017-03-01

    ALICE is one of the four large experiments at the CERN Large Hadron Collider (LHC). As a complement to its Heavy-Ion physics program, ALICE started during Run 1 of LHC an extensive program dedicated to the study of proton-proton diffractive processes. In order to optimize its trigger efficiencies and purities in selecting diffractive events, the ALICE Collaboration installed a very forward AD detector during the Long Shut Down 1 of LHC. This new forward detector system consists of two stations made of two layers of scintillator pads, one station on each side of the interaction point. With this upgrade, ALICE has substantially increased its forward physics coverage, including the double rapidity gap based selection of central production, as well as the measurements of inclusive diffractive cross sections.

  8. Thermal and transport properties in central heavy-ion reactions around a few hundred MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Deng, X. G.; Ma, Y. G.; Veselský, M.

    2016-10-01

    The thermalization process of nuclear matter in the central fireball region of heavy-ion collisions is investigated by employing an extended Boltzmann-Uehling-Uhlenbeck model, namely, the van der Waals Boltzmann-Uehling-Uhlenbeck (VdWBUU) model. The temperature (T ) is extracted by the quantum fermion fluctuation approach and other thermodynamic quantities, such as the density (ρ ), entropy density (s ), shear viscosity (η ), isospin diffusivity (DI), and heat conductivity (κ ), are also deduced. The liquidlike and gaslike phase signs are discussed through the behavior of the shear viscosity during the heavy-ion collision process in the VdWBUU model.

  9. Hydrogeological and hydrochemical features of an area polluted by heavy metals in central Nicaragua

    NASA Astrophysics Data System (ADS)

    Mendoza, J. A.; Dahlin, T.; Barmen, G.

    2006-09-01

    Geophysical and hydrochemical surveys were used to investigate the hydrogeological conditions in one of the Río Sucio microbasins, in central Nicaragua. Zones of vertical structures (i.e. fractures and quartz veins) and weathering were mapped using Continuous Vertical Electrical Soundings (CVES), as such zones are of major importance for groundwater transport. Water from the springs was analysed to determine concentrations of major ions and heavy metals. Low ion concentrations and 18O analyses indicate that the springs occur close to their recharge areas and there is a relatively rapid groundwater circulation. Mercury (Hg) content in the springs was low, while comparatively high amounts of lead (Pb) were found. The results presented here demonstrate the important function of weathering and tectonics in the occurrence of groundwater systems in the basin. Hg and Pb found in the springs’ water reveal the existence of an increase in pollution sources disseminating in the area. More than 100 years of using mercury in the gold-mining industry and releasing wastes into rivers has affected water quality and ecosystems. Further investigations are needed in this area to determine the groundwater vulnerability to this pollution as this resource may be needed in the future.

  10. Hydrogeological and hydrochemical features of an area polluted by heavy metals in central Nicaragua

    NASA Astrophysics Data System (ADS)

    Mendoza, J. A.; Dahlin, T.; Barmen, G.

    2006-06-01

    Geophysical and hydrochemical surveys were used to investigate the hydrogeological conditions in one of the Río Sucio microbasins, in central Nicaragua. Zones of vertical structures (i.e. fractures and quartz veins) and weathering were mapped using Continuous Vertical Electrical Soundings (CVES), as such zones are of major importance for groundwater transport. Water from the springs was analysed to determine concentrations of major ions and heavy metals. Low ion concentrations and 18O analyses indicate that the springs occur close to their recharge areas and there is a relatively rapid groundwater circulation. Mercury (Hg) content in the springs was low, while comparatively high amounts of lead (Pb) were found. The results presented here demonstrate the important function of weathering and tectonics in the occurrence of groundwater systems in the basin. Hg and Pb found in the springs’ water reveal the existence of an increase in pollution sources disseminating in the area. More than 100 years of using mercury in the gold-mining industry and releasing wastes into rivers has affected water quality and ecosystems. Further investigations are needed in this area to determine the groundwater vulnerability to this pollution as this resource may be needed in the future.

  11. Sediment evidence of early eutrophication and heavy metal pollution of Lake Mälaren, central Sweden.

    PubMed

    Renberg, I; Bindler, R; Bradshaw, E; Emteryd, O; McGowan, S

    2001-12-01

    Lake Mälaren is the water supply and recreation area for more than 1 million people in central Sweden and subject to considerable environmental concern. To establish background data for assessments of contemporary levels of trophy and heavy metal pollution, sediment cores from the lake were analyzed. Diatom-inferred lake-water phosphorus concentrations suggest that pre-20th century nutrient levels in Södra Björkfjärden, a basin in the eastern part of Mälaren, were higher (c. 10-20 micrograms TP L-1) than previously assumed (c. 6 micrograms TP L-1). Stable lead isotope and lead concentration analyses from 3 basins (S. Björkfjärden, Gisselfjärden and Asköfjärden) show that the lake was polluted in the 19th century and earlier from extensive metal production and processing in the catchment, particularly in the Bergslagen region. The lake has experienced a substantial improvement of the lead pollution situation in the 20th century following closure of the mining and metal industry. The lead pollution from the old mining industry was large compared to late-20th century pollution from car emissions, burning of fossil fuels and modern industries.

  12. Investigation of the commensurate magnetic structure in the heavy-fermion compound CePt2In7 using magnetic resonant x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Gauthier, Nicolas; Wermeille, Didier; Casati, Nicola; Sakai, Hironori; Baumbach, Ryan E.; Bauer, Eric D.; White, Jonathan S.

    2017-08-01

    We investigated the magnetic structure of the heavy-fermion compound CePt2In7 below TN=5.34 (2 ) K using magnetic resonant x-ray diffraction at ambient pressure. The magnetic order is characterized by a commensurate propagation vector k1 /2=(1/2 ,1/2 ,1/2 ) with spins lying in the basal plane. Our measurements did not reveal the presence of an incommensurate order propagating along the high-symmetry directions in reciprocal space but cannot exclude other incommensurate modulations or weak scattering intensities. The observed commensurate order can be described equivalently by either a single-k structure or by a multi-k structure. Furthermore we explain how a commensurate-only ordering may explain the broad distribution of internal fields observed in nuclear quadrupolar resonance experiments [Sakai et al., Phys. Rev. B 83, 140408 (2011), 10.1103/PhysRevB.83.140408] that was previously attributed to an incommensurate order. We also report powder x-ray diffraction showing that the crystallographic structure of CePt2In7 changes monotonically with pressure up to P =7.3 GPa at room temperature. The determined bulk modulus B0=81.1 (3 ) GPa is similar to those of the Ce-115 family. Broad diffraction peaks confirm the presence of pronounced strain in polycrystalline samples of CePt2In7 . We discuss how strain effects can lead to different electronic and magnetic properties between polycrystalline and single crystal samples.

  13. Crystallization and preliminary X-ray diffraction analysis of central structure domains from mumps virus F protein

    SciTech Connect

    Liu, Yueyong; Xu, Yanhui; Zhu, Jieqing; Qiu, Bingsheng; Rao, Zihe; Gao, George F.; Tien, Po

    2005-09-01

    Single crystals of the central structure domains from mumps virus F protein have been obtained by the hanging-drop vapour-diffusion method. A diffraction data set has been collected to 2.2 Å resolution. Fusion of members of the Paramyxoviridae family involves two glycoproteins: the attachment protein and the fusion protein. Changes in the fusion-protein conformation were caused by binding of the attachment protein to the cellular receptor. In the membrane-fusion process, two highly conserved heptad-repeat (HR) regions, HR1 and HR2, are believed to form a stable six-helix coiled-coil bundle. However, no crystal structure has yet been determined for this state in the mumps virus (MuV, a member of the Paramyxoviridae family). In this study, a single-chain protein consisting of two HR regions connected by a flexible amino-acid linker (named 2-Helix) was expressed, purified and crystallized by the hanging-drop vapour-diffusion method. A complete X-ray data set was obtained in-house to 2.2 Å resolution from a single crystal. The crystal belongs to space group C2, with unit-cell parameters a = 161.2, b = 60.8, c = 40.1 Å, β = 98.4°. The crystal structure will help in understanding the molecular mechanism of Paramyxoviridae family membrane fusion.

  14. Conformational change of helix G in the bacteriorhodopsin photocycle: investigation with heavy atom labeling and x-ray diffraction.

    PubMed Central

    Oka, T; Kamikubo, H; Tokunaga, F; Lanyi, J K; Needleman, R; Kataoka, M

    1999-01-01

    According to the current structural model of bacteriorhodopsin, Ile222 is located at the cytoplasmic end of helix G. We labeled the single cysteine of the site-directed mutant Ile222 --> Cys with p-chloromercuribenzoic acid and determined the position of the labeled mercury by x-ray diffraction in the unphotolyzed state, and in the MN photointermediate accumulated in the presence of guanidine hydrochloride at pH 9.5. According to the difference Fourier maps between the MN intermediate and the unphotolyzed state, the structural change in the MN intermediate was not affected by mercury labeling. The difference Fourier map between the labeled and the unlabeled I222C gave the position of the mercury label. This information was obtained for both the unphotolyzed state and the MN intermediate. We found that the position of the mercury at residue 222 is shifted by 2.1 +/- 0.8 A in the MN intermediate. This agrees with earlier results that suggested a structural change in the G helix. The movement of the mercury label is so large that it must originate from a cooperative conformational change in the helix G at its cytoplasmic end, rather than from displacement of residue 222. Because Ile222 is located at the same level on the z coordinate as Asp96, the structural change in the G helix could have the functional role of perturbing the environment and therefore the pKa of this functionally important aspartate. PMID:9916033

  15. Heavy element accumulation in Evernia prunastri lichen transplants around a municipal solid waste landfill in central Italy.

    PubMed

    Nannoni, Francesco; Santolini, Riccardo; Protano, Giuseppe

    2015-09-01

    This paper presents the results of a biomonitoring study to evaluate the environmental impact of airborne emissions from a municipal solid waste landfill in central Italy. Concentrations of 11 heavy elements, as well as photosynthetic efficiency and cell membrane integrity were measured in Evernia prunastri lichens transplanted for 4months in 17 monitoring sites around the waste landfill. Heavy element contents were also determined in surface soils. Analytical data indicated that emissions from the landfill affected Cd, Co, Cr, Cu, Ni, Pb, Sb and Zn concentrations in lichens transplanted within the landfill and along the fallout direction. In these sites moderate to severe accumulation of these heavy elements in lichens was coupled with an increase in cell membrane damage and decrease in photosynthetic efficiency. Nevertheless, results indicated that landfill emissions had no relevant impact on lichens, as heavy element accumulation and weak stress symptoms were detected only in lichen transplants from sites close to solid waste. The appropriate management of this landfill poses a low risk of environmental contamination by heavy elements. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Evaluate the radioactivity along the central thimble hole of a decommissioned heavy water research reactor using TLD approach.

    PubMed

    Lee, Lun-Hui; Sher, Hai-Feng; Lu, I-Hsin; Pan, Lung-Kwang

    2012-04-01

    The radioactivity along the central thimble hole of a decommissioned heavy water research reactor, TRR, was evaluated using TLD approach. The decay radionuclide was verified to be Co-60. The dose along the TRR central thimble hole was detected and revised by performing an unfolding analysis. The revised data reduced to 70-90% of the original data (for example, the maximum dose rate was reduced from 6447 to 4831 mSv/h,) and were more reliable. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Heavy metals monitoring at a Mediterranean natural ecosystem of Central Italy. Trends in different environmental matrixes.

    PubMed

    Morselli, Luciano; Brusori, Barbara; Passarini, Fabrizio; Bernardi, Elena; Francaviglia, Rosa; Gataleta, Licia; Marchionni, Maria; Aromolo, Rita; Benedetti, Anna; Olivieri, Piera

    2004-04-01

    The study deals with the evaluation of the impact of heavy metal pollution on a Mediterranean natural ecosystem, and presents the results derived from a monitoring of heavy metals in different environmental matrixes (atmospheric dry depositions, suspended particulate matter (SPM) and stemflow of forest trees). Two sites in Castelporziano Presidential Estate (Rome), one internal and one near the sea-side, were chosen in order to assess the differences in pollutant load. Results showed that heavy metal contamination can arise from local anthropogenic activities, in particular road traffic, and long-range pollution, from industrial and artisan activities near Rome.

  18. Benthic foraminifera for heavy metal pollution monitoring: A case study from the central Adriatic Sea coast of Italy

    NASA Astrophysics Data System (ADS)

    Frontalini, F.; Coccioni, R.

    2008-01-01

    Benthic foraminifera are increasingly used as environmental bio-indicators of pollution in coastal and marginal marine settings. Their community structure provides information on the general characteristics of the environment and some species are sensitive to specific environmental parameters. Among various criteria, the occurrence of test abnormalities may represent a useful bioindicator for monitoring environmental impacts in coastal regions. A study of living benthic foraminifera was carried out in 42 sediment samples collected from the central Adriatic coast of Italy. Benthic foraminiferal assemblages from this area are rich, well preserved, and dominated by Ammonia parkinsoniana, and subordinately by Ammonia tepida, Aubignyna perlucida, Eggerella scabra, and Nonionella turgida. Heavy metal concentrations have been analysed which indicate low polluted environmental conditions. Foraminiferal species and heavy metal concentrations were investigated both with bivariate (correlation matrix) and multivariate techniques of principal component analysis (PCA) and cluster analysis. Statistical analysis shows a possible control of these pollutants both on the taxonomic composition of the benthic foraminiferal assemblages and the development of test malformations. Increasing heavy metal contents lead to an increase in relative abundance of A. tepida A. perlucida, N. turgida and E. scabra, and a relative concurrent decrease in relative abundance of A. parkinsoniana and higher percentages of deformed specimens (FAI) and species (FMI). Our results confirm that A. parkinsoniana prefers clean to low polluted environments and show that it is a very sensitive and un-tolerant species to heavy metal pollution being deeply affected by heavy metal content even at low concentrations. Our findings also confirm the capacity of the A. tepida to tolerate increasing heavy metal concentrations, and highlights that A. perlucida, N. turgida and E. scabra can be considered as tolerant species

  19. Heavy metal tolerance in the psychrotolerant Cryptococcus sp. isolated from deep-sea sediments of the Central Indian Basin.

    PubMed

    Singh, Purnima; Raghukumar, Chandralata; Parvatkar, Rajesh Ramnath; Mascarenhas-Pereira, M B L

    2013-03-01

    A deep-sea isolate of the psychrotolerant yeast Cryptococcus sp. (NIOCC#PY13) obtained from polymetallic nodule-bearing sediments of the Central Indian Basin was examined for its capacity to grow in the presence of various concentrations of the heavy metal salts i.e., ZnSO4 , CuSO4 , Pb(CH3 COO)2 and CdCl2 . It demonstrated considerable growth in the presence of 100 mg/l concentrations of the above-mentioned four heavy metal salts both at 30°C and 15°C. This strain tolerated comparatively higher levels of these four metal salts than other deep-sea and terrestrial yeast isolates belonging to Cryptococcus, Rhodotorula, Rhodosporidium and Sporidiobolus spp. Optimum pH for growth of this isolate was in the range of 6-8 in the presence of heavy metal salts at these two temperatures. Scanning electron microscopic (SEM) studies exhibited altered cell surface morphology of the cells under the influence of heavy metals compared to that with control. The adsorption of heavy metals to the cells was demonstrated by FTIR and EDAX analysis. As evidenced by atomic absorption spectrophotometric (AAS) analysis, about 30-90% of the heavy metals were removed from the culture supernatant after 4 days of growth at 30°C. This deep-sea yeast isolate appears to be a potential candidate for bioremediation of metal-contaminated sites. Moreover, its metal tolerance properties provide a significant insight into its ecological role and adaptations to growth in such extreme conditions. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Stress induced by heavy metals on breeding of magpie (Pica pica) from central Iran.

    PubMed

    Zarrintab, Mohammad; Mirzaei, Rouhollah

    2017-09-01

    The aim of this study was to address the impacts of some heavy metals (Cd, Pb, Zn, Ni and Cu) contamination on laying behavior, egg quality and breeding performance of Pica pica in north of Isfahan Province, Iran. During the breeding season of 2013, magpie's egg content and eggshell as well as nestling excrements and feathers were collected and total concentrations of heavy metals were measured by ICP-OES. Except for Zn in nestling feathers, the significantly higher concentrations of heavy metals were observed in nestling excrements than other samples. Also, comparison of heavy metals concentrations in egg content and eggshell showed that egg content had significantly higher concentrations of Zn and Pb, instead eggshell had significantly higher amount of Cu and Cd. Except for Cu, all heavy metals concentrations in eggshell had a negative relationship with morphological characters; and also concentration of Cu in egg content showed a significantly negative correlation with egg weight and volume. The most of heavy metals in nestling feathers and excrements had strongly positive correlations with each other. Also all heavy metals levels in eggshell and egg content had significantly positive correlations (except for Cu). Unhatched eggs had significantly lower weight but also greater levels of Zn, Cd, and Pb, than randomly collected eggs. No significant differences were observed for morphometric measurements of eggs between different sites, however, a decreased gradient was observed in egg volume toward the brick kiln site. Samples collected in brick kiln site accumulated higher concentrations of heavy metals than other sites. Although numbers of clutch size in brick kiln site were significantly higher than other sites, however, other breeding variable were lower than other sites. It can be suggested that ecosystem contamination may be caused to decrease the reproduction rate of Pica pica in brick kiln, probably by laying more poor quality eggs per clutch and nestling

  1. Spatial distribution and transport characteristics of heavy metals around an antimony mine area in central China.

    PubMed

    Li, Xin; Yang, Hong; Zhang, Chang; Zeng, Guangming; Liu, Yunguo; Xu, Weihua; Wu, Youe; Lan, Shiming

    2017-03-01

    The spatial distribution and transport characteristics of heavy metals in an antimony mine area (Xikuangshan, China) were systematically studied using a field survey and geostatistical analytical methods. In the study area, 52 soil and sediment samples were collected from bare land, grassland, woodland and river sediments covering a surface area of 20 km(2). The soil properties and heavy metal concentrations were measured by wavelength dispersive X-ray fluorescence spectrometry and inductively coupled plasma-mass spectrometry, respectively. Correlation analysis and principal component analysis suggest that Cu, Zn, Cd, As, Pb and Sb can be attributed to anthropogenic inputs, whereas Cr, Mn and Ni are of natural origin. Distribution maps of heavy metals were generated using the Kriging interpolation method to identify their distribution trends. The results show the influence of wind, river, distance and vegetation on the spatial distribution. The results also revealed that windborne transport may play a significant role in the spreading of contaminants. In addition, the environmental risk of heavy metal pollution was evaluated using their geoaccumulation indexes in the whole region. All of the results indicate that the heavy metal distributions in the soils were consistent with the local prevailing wind direction. In addition, the environmental quality could be seriously threatened by heavy metal contaminants from the smelter and tailings.

  2. Nuclear stopping and energy removal in central collisions between heavy ions of 8-115 AMeV

    NASA Astrophysics Data System (ADS)

    Sun, Rulin

    Central and mid-central collisions have been studied for 40Ar + Cu, Ag and Au from 8 to 115 A MeV. Slow moving heavy residual nuclei were observed along with near 4π detection (including ~ 0.5° to 165° in the lab.) of light charged particles and fragments. A continuous increase in the multiplicities from the most violent collisions is observed with increasing projectile energy. The heavy residual nuclei are found to accept a majority fraction of the projectile momentum only up to ~ 44 A MeV, but then to yield this majority fraction to the ejectile spray for 65-115 A MeV. This confirms a dominance of familiar incomplete fusion processes up to 44 A MeV, but then demonstrates a succession to splintering central collisions, a new reaction class for the Fermi energy domain. For the central collisions, isotropic and forward-peaked components in the frame of the heaviest fragment are separated for each ejectile type. The nuclear stopping is characterized via average longitudinal momenta for the heaviest fragment and for each ejectile type. Comparison of measured values of longitudinal volecity for the heaviest fragment with predictions of the Boltzmann- Uehling-Uhlenbeck (BUU) model shows the over estimation of nuclear stopping by the model. Ejectiles emitted isotropically in the frame of the heaviest fragment define average deposition energies that reach 1-2 GeV, but there is no clear signature for a liquid-gas phase transition. Collective tranverse flow is measured by azimuthal correlation functions between each ejectile and the reaction plane, determined by vector summation of projectile-like-fragments. The energy at which collective transverse flow in the reaction plane disappears, termed the balance energy, is found to decrease as the mass of the target increases. The disassembly of the heaviest nuclei for these relatively high energy reactions is compared to calculations by multifragmentation models. Large divergences appear between the experimental data and

  3. Heavy ion reaction measurements with the EOS TPC (looking for central collisions with missing energy)

    SciTech Connect

    Wieman, H.H.; EOS Collaboration

    1994-05-01

    The EOS TPC was constructed for complete event measurement of heavy ion collisions at the Bevalac. We report here on the TPC design and some preliminary measurements of conserved event quantities such as total invariant mass, total momentum, total A and Z.

  4. Heavy Metal Contamination in Soil and Brown Rice and Human Health Risk Assessment near Three Mining Areas in Central China

    PubMed Central

    2017-01-01

    Background Metal mining and waste discharge lead to regional heavy metal contamination and attract major concern because of the potential risk to local residents. Methods This research was conducted to determine lead (Pb), cadmium (Cd), arsenic (As), manganese (Mn), and antimony (Sb) concentrations in soil and brown rice samples from three heavy metal mining areas in Hunan Province, central China, and to assess the potential health risks to local inhabitants. Results Local soil contamination was observed, with mean concentrations of Cd, Pb, Sb, and As of 0.472, 193.133, 36.793, and 89.029 mg/kg, respectively. Mean concentrations of Cd, Pb, Sb, Mn, and As in brown rice were 0.103, 0.131, 5.175, 6.007, and 0.524 mg/kg, respectively. Daily intakes of Cd, As, Sb, Pb, and Mn through brown rice consumption were estimated to be 0.011, 0.0002, 0.004, 0.0001, and 0.0003 mg/(kg/day), respectively. The combined hazard index for the five heavy metals was 22.5917, and the total cancer risk was 0.1773. Cd contributed most significantly to cancer risk, accounting for approximately 99.77% of this risk. Conclusions The results show that potential noncarcinogenic and carcinogenic health risks exist for local inhabitants and that regular monitoring of pollution to protect human health is urgently required.

  5. Heavy metal and organochlorine compound concentrations in tissues of raccoons from east-central Michigan

    SciTech Connect

    Herbert, G.B.; Peterle, T.J. )

    1990-02-01

    Organochlorine (OC) pesticides and related compounds and heavy metals are persistent contaminants in the environment. Bioconcentration and biomagnification are well reported for organochlorine compounds. These compounds have a great potential for causing wildlife mortality or serious behavioral, reproductive, carcinogenic, teratogenic, and mutagenic effects, along with specific organ toxicity. The pervasive nature of toxic substances in the environment necessitates some knowledge for potential exposure of wildlife species. Without baseline values of contaminant loads for selected indicator species it is impossible to determine when abnormal or pathological conditions exist in wild populations. The purpose of this study was to provide baseline values for selected environmental contaminants in the raccoon (Procyon lotor), a potential indicator species for wildlife and to see if heavy metal accumulation was related to age or sex.

  6. The Environment Quality, Speciation and their Origins of Heavy Metals in Surficial Sediments in Central Bohai Sea, China

    NASA Astrophysics Data System (ADS)

    Liu, M.; Fan, D.; Han, Z.; Liao, Y.; Chen, B.; Yang, Z.

    2016-02-01

    The concentrations and speciations of heavy metals (Cu, Co, Ni, Zn, Pb, Cr and Cd) in surface and core sediments collected from the central Bohai Sea were analyzed by ICP-MS, to evaluate their distribution / fractionation, pollution status and sources. The results showed that Cd exhibited gradual increasing vertically, while others were stable or declined slightly in core sediments. Metals showed higher values in `central mud area of the Bohai Sea' and the coastal area of the Bohai Bay in surface sediments. Residual fractions were the dominant forms of Cu, Co, Ni, Zn and Cr in the surface sediments, while Cd and Pb had large proportions of the total concentration in the non-residual fractions. Both the contamination factors and the geo-accumulation index indicated that Cu, Co, Ni, Cr were not polluted, while Pb, Zn, Cd were in moderate contamination. The ecological risk assessment (by sepeciations) indicated that the sediments were unpolluted with respect to the heavy metals Co, Ni and Cr and unpolluted to moderately polluted with respect to Cu, Zn, Cd and Pb. Compared with sediment quality guidelines (SQGs), Cu, Zn, Cr, Pb, Cd were likely to produce occasional adverse biological effects, while Ni showed possible ecotoxicological risks. The combined levels of the metals have a 21% probability of being toxic. Elements Cr, Co and Ni were mainly natural origined and significantly affected by the composition of sediments. Cu, Zn, Pb and especially Cd may be influenced by human activities.

  7. Interference from the Robledo DSN Transmitters to Central Madrid IMT-2000/UMTS System through Terrain Diffraction at S-Band

    NASA Technical Reports Server (NTRS)

    Ho, Christian M.; Sue, Miles K.; Peng, Ted K.; Smith, Ernest K.

    2002-01-01

    This study evaluates the possible interference from DSN Robledo 70-m transmitter with Madrid IMT-2000/UMTS wireless users in Spain as both systems will share the same frequency band. Using the effective earth radius, the 50 km terrain profile between Robledo and Madrid is modified and reconstructed. The diffraction propagation losses due to mountain peaks are calculated for the receivers in Madrid urban area. The mountains along the path are simplified into a rounded knife-edge and a rounded obstacle. The results show that for a near surface receiver (1.5 m above the ground) in Madrid, interference signal powers received are less than -135 dBm, which is far below the -109 dBm, the IMT-2000 wireless phone threshold. When a receiver is located at about 40 m above the ground (e.g., the top of Clock Tower of Cibeles Palace), diffraction will generate interference power less than -115 dBm. We find that our calculation results are basically consistent with those from the Longley-Rice model, while the latter has smaller loss because of the low resolution terrain profile used. As a comparison, we also find that the measurements of interference powers of -121.2 dBm at the top of Clock tower is in the range of the estimation. We conclude that the interference through the diffraction mechanism will not cause any problem to IMT-2000/UMTS users at near the surface of Madrid urban area.

  8. Interference from the Robledo DSN Transmitters to Central Madrid IMT-2000/UMTS System through Terrain Diffraction at S-Band

    NASA Technical Reports Server (NTRS)

    Ho, Christian M.; Sue, Miles K.; Peng, Ted K.; Smith, Ernest K.

    2002-01-01

    This study evaluates the possible interference from DSN Robledo 70-m transmitter with Madrid IMT-2000/UMTS wireless users in Spain as both systems will share the same frequency band. Using the effective earth radius, the 50 km terrain profile between Robledo and Madrid is modified and reconstructed. The diffraction propagation losses due to mountain peaks are calculated for the receivers in Madrid urban area. The mountains along the path are simplified into a rounded knife-edge and a rounded obstacle. The results show that for a near surface receiver (1.5 m above the ground) in Madrid, interference signal powers received are less than -135 dBm, which is far below the -109 dBm, the IMT-2000 wireless phone threshold. When a receiver is located at about 40 m above the ground (e.g., the top of Clock Tower of Cibeles Palace), diffraction will generate interference power less than -115 dBm. We find that our calculation results are basically consistent with those from the Longley-Rice model, while the latter has smaller loss because of the low resolution terrain profile used. As a comparison, we also find that the measurements of interference powers of -121.2 dBm at the top of Clock tower is in the range of the estimation. We conclude that the interference through the diffraction mechanism will not cause any problem to IMT-2000/UMTS users at near the surface of Madrid urban area.

  9. Neutron skin and centrality classification in high-energy heavy-ion collisions at the LHC

    NASA Astrophysics Data System (ADS)

    Paukkunen, Hannu

    2015-05-01

    The concept of centrality in high-energy nuclear collisions has recently become a subject of an active debate. In particular, the experimental methods to determine the centrality that have given reasonable results for many observables in high-energy lead-lead collisions at the LHC have led to surprising behavior in the case of proton-lead collisions. In this letter, we discuss the possibility to calibrate the experimental determination of centrality by asymmetries caused by mutually different spatial distributions of protons and neutrons inside the nuclei - a well-known phenomenon in nuclear physics known as the neutron-skin effect.

  10. Assessment of factors related to heavy metals distribution in abandoned mining soils in Madrid, central Spain

    NASA Astrophysics Data System (ADS)

    Torres, Manuel; Carral, Pilar; Alvarez, Ana M.; Hernández, Zulimar; Lorena, Recio-Vázquez; Marques, Maria J.; Almendros, Gonzalo

    2013-04-01

    Exploitation of metallic mineral deposits and its subsequent abandonment in last decades has lead to significant environmental hazard for natural systems. The present study concerns the distribution and mobility of heavy metals and trace elements mainly As, Cu, Cd, Co, Mn and V, in sulphide-rich soils. The site studied (Sierra de Guadarrama, Garganta de los Montes, Madrid) is at 1200 m asl. Soils are Humic and Dystric Cambisols (WRB) developed on gneisses; the main minerals consist of sulphides and include chalcopyrite, pyrite, marcasite, galena and arsenopyrite. Concentration data of the different species of heavy metals as dependent variables in addition to a series of independent variables mainly soil organic matter were subjected to multivariate chemometric treatments including multidimensional scaling (MDS), principal component analysis (PCA) and support vector machine (SVM) for a preliminary survey on the possible role of soil organic matter in the distribution and speciation of heavy metals in soils. The soil heavy metals speciation was determined using the BCR (Community Bureau of Reference, European Commission) sequential extraction procedure and analysed by ICP-MS. The total contents of these elements were calculated as the sum of the four BCR fractions. The results showed element concentrations decreasing with the distance from the source of pollution. The highest amounts of As and Mn, and Cu, Cd, Co and V were found at 10 and 100 m respectively. These values exceed the allowed limits of the environmental regulation. The percentages of extractable elements (step one of BCR) in relation to total elements show that Cu and Cd were significantly more easily extractable than the other elements. Metal availability in soils was generally controlled by total metal concentration. Data processing techniques coincided in pointing out the association of high levels of organic matter with the concentrations of elements extracted just in the most available forms: i

  11. Central and Peripheral Timing Variability in Children with Heavy Prenatal Alcohol Exposure

    PubMed Central

    Simmons, Roger W.; Levy, Susan S.; Riley, Edward P.; Madra, Naju M.; Mattson, Sarah N.

    2008-01-01

    Background The study examined whether prenatal alcohol exposure is associated with increased motor timing variability when the timing response is partitioned into central clock variability, which indexes information processing at the central nervous system (CNS) level and motor delay variability, which reflects timing processes at the level of the peripheral nervous system (PNS). Methods Eighteen children with histories of prenatal alcohol exposure and 22 control children were assigned to young (7–11 years) or older (12–17 years) groups. Children tapped a single response key with the index finger in synchrony with a series of externally generated tones (the paced phase). At the conclusion of these tones, children continued tapping (the continuation phase) while attempting to maintain the same rate of tapping imposed by the paced phase. Two blocks of tapping were completed with inter-tone-intervals set at either 400 or 900 ms. Inter-response interval, central clock variability, and motor delay variability produced during the continuation phase were the dependent variables. Results Mean inter-response interval for the four groups did not differ for either time interval. Central clock variability produced by the young alcohol-exposed group was significantly greater than the two older groups for the 400 ms interval and all other groups for the 900 ms interval. Motor delay variability produced by the young alcohol-exposed group was significantly greater than the other three groups for both time intervals. Central and motor delay variability in children with and without alcohol exposure was directly related to the duration of the interval to be reproduced. Conclusions Central and peripheral timing variability was significantly greater for the young alcohol-exposed children. This atypical timing may be related to the teratogenic effects of alcohol, although the negative effects are limited to younger alcohol-exposed children since there were no differences in central

  12. Radioactivity levels and heavy metals in the urban soil of Central Serbia.

    PubMed

    Milenkovic, B; Stajic, J M; Gulan, Lj; Zeremski, T; Nikezic, D

    2015-11-01

    Radioactivity concentrations and heavy metal content were measured in soil samples collected from the area of Kragujevac, one of the largest cities in Serbia. The specific activities of (226)Ra, (232)Th, (40)K and (137)Cs in 30 samples were measured by gamma spectrometry using an HPGe semiconductor detector. The average values ± standard deviations were 33.5 ± 8.2, 50.3 ± 10.6, 425.8 ± 75.7 and 40.2 ± 26.3 Bq kg(-1), respectively. The activity concentrations of (226)Ra, (232)Th and (137)Cs have shown normal distribution. The annual effective doses, radium equivalent activities, external hazard indexes and excess lifetime cancer risk were also estimated. A RAD7 device was used for measuring radon exhalation rates from several samples with highest content of (226)Ra. The concentrations of As, Co, Cr, Cu, Mn, Ni, Pb and Zn were measured, as well as their EDTA extractable concentrations. Wide ranges of values were obtained, especially for Cr, Mn, Ni, Pb and Zn. The absence of normal distribution indicates anthropogenic origin of Cr, Ni, Pb and Zn. Correlations between radionuclide activities, heavy metal contents and physicochemical properties of analysed soil were determined by Spearman correlation coefficient. Strong positive correlation between (226)Ra and (232)Th was found.

  13. Centrality Dependent Strange Baryon Production in P-A and its Implications for Heavy Ion Collisions

    SciTech Connect

    Soltz, R.

    2000-09-22

    BNL E910 has measured strange baryon production as a function of collision centrality for 17.5 GeV/c p-Au collisions. Collision centrality is defined by v{sub 1} the mean number projectile-nucleon interactions estimated from the ''grey'' track multiplicity. The measured {Lambda} yield increases faster than the participant scaling expectation for v {le} 3 and then saturates. A simple parameterization of this dependence applied to nucleus-nucleus collisions reproduces the measured E866 km. and WA97 {Lambda} centrality dependent yields. The increase in {Lambda} production to v {le} 3 is also evident for {Lambda}s which are leading baryons, in disagreement with predictions from RQMD.

  14. Cumulants of multiplicity distributions in most-central heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Xu, Hao-jie

    2016-11-01

    I investigate the volume corrections on cumulants of total charge distributions and net proton distributions. The required volume information is generated by an optical Glauber model. I find that the corrected statistical expectations of multiplicity distributions mimic the negative binomial distributions at noncentral collisions, and they tend to approach the Poisson ones at most-central collisions due to the "boundary effects," which suppress the volume corrections. However, net proton distributions and reference multiplicity distributions are sensitive to the external volume fluctuations at most-central collisions, which imply that one has to consider the details of volume distributions in event-by-event multiplicity fluctuation studies.

  15. Estimation of sediment yield from subsequent expanded landslides after heavy rainfalls : a case study in central Hokkaido, Japan

    NASA Astrophysics Data System (ADS)

    Koshimizu, K.; Uchida, T.

    2015-12-01

    Initial large-scale sediment yield caused by heavy rainfall or major storms have made a strong impression on us. Previous studies focusing on landslide management investigated the initial sediment movement and its mechanism. However, integrated management of catchment-scale sediment movements requires estimating the sediment yield, which is produced by the subsequent expanded landslides due to rainfall, in addition to the initial landslide movement. This study presents a quantitative analysis of expanded landslides by surveying the Shukushubetsu River basin, at the foot of the Hidaka mountain range in central Hokkaido, Japan. This area recorded heavy rainfall in 2003, reaching a maximum daily precipitation of 388 mm. We extracted the expanded landslides from 2003 to 2008 using aerial photographs taken over the river area. In particular, we calculated the probability of expansion for each landslide, the ratio of the landslide area in 2008 as compared with that in 2003, and the amount of the expanded landslide area corresponding to the initial landslide area. As a result, it is estimated 24% about probability of expansion for each landslide. In addition, each expanded landslide area is smaller than the initial landslide area. Furthermore, the amount of each expanded landslide area in 2008 is approximately 7% of their landslide area in 2003. Therefore, the sediment yield from subsequent expanded landslides is equal to or slightly greater than the sediment yield in a typical base flow. Thus, we concluded that the amount of sediment yield from subsequent expanded landslides is lower than that of initial large-scale sediment yield caused by a heavy rainfall in terms of effect on management of catchment-scale sediment movement.

  16. Those Left Behind: Recent Social Changes in a Heavy Emigration Area of North Central New Mexico

    ERIC Educational Resources Information Center

    Leonard, Olen E.; Hannon, John H.

    1977-01-01

    Examining social and economic change associated with a recent mass exodus of Spanish surnamed populations from rural villages in north-central New Mexico, this article addresses attitudes of those left behind and postulates that while the impact of migration has been felt throughout the area, its intensity has fluctuated among villages. (Author/JC)

  17. Those Left Behind: Recent Social Changes in a Heavy Emigration Area of North Central New Mexico

    ERIC Educational Resources Information Center

    Leonard, Olen E.; Hannon, John H.

    1977-01-01

    Examining social and economic change associated with a recent mass exodus of Spanish surnamed populations from rural villages in north-central New Mexico, this article addresses attitudes of those left behind and postulates that while the impact of migration has been felt throughout the area, its intensity has fluctuated among villages. (Author/JC)

  18. Heavy metals concentration in plants growing on mine tailings in Central Mexico.

    PubMed

    Franco-Hernández, M O; Vásquez-Murrieta, M S; Patiño-Siciliano, A; Dendooven, L

    2010-06-01

    Metal concentrations were measured in plants growing on heavily contaminated tailings from a mine active since about 1800 in San Luis Potosí (Mexico). Viguiera dentata (Cav.) Spreng., Parthenium bipinnatifidum (Ort.) Rollins, Flaveria angustifolia (Cav.) Pers., F. trinervia (Spreng.) C. Mohr. and Sporobolusindicus (L.) R. Br. were tolerant to high As, Cu, Pb and Zn concentrations. Of those, S.indicus excluded heavy metals from its shoots, while P. bipinnatifidum and F. angustifolia accumulated them. V. dentata and P. bipinnatifidum were accumulators of As, but not hyperaccumulators. It was found that V. dentata,P. bipinnatifidum, F. angustifolia, F. trinervia and S.indicus, could be used to vegetate soils contaminated with As, Cu, Pb and Zn. Ambrosiaartemisifolia could be used to remediate soils contaminated with Zn, S. amplexicaulis those with Cu and F. angustifolia and F. trinervia those with As, as they have a strong capacity to accumulate those metals.

  19. Extracting the shear viscosity of the quark-gluon plasma from flow in ultra-central heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Luzum, Matthew; Ollitrault, Jean-Yves

    2013-05-01

    We propose a method for extracting the shear viscosity over entropy density ratio (η/s) of the quark-gluon plasma from experimental data. We argue that uncertainty due to poor knowledge of the earliest stages of a heavy-ion collision is smallest for ultra-central events. The most precise value of η/s can thus be obtained from a global fit to pT-integrated Fourier harmonics of azimuthal correlations. We further outline a method for quantifying the overall uncertainty in the extracted value. Only after a comprehensive and systematic accounting of all sources of uncertainty can a reliable measurement be claimed. In these proceedings we report preliminary results; full and final results will be presented in a separate publication.

  20. Radial space potential measurements in the central cell of the tandem mirror experiment with a heavy-ion-beam probe

    SciTech Connect

    Hallock, G.A.

    1983-04-11

    Spatial and temporal profiles of the space potential in the central-cell midplane of TMX have been obtained with a heavy-ion-beam probe. The absolute accuracy of measurements is +- 25 volts (with respect to the machine vacuum walls) with a resolution of approx. 2 volts. During moderate fueling with the gas boxes (i/sub gas/ approx. = 1200 Atom-Amperes D/sub 2/), the plasma potential is parabolic to at least 25 cm radius, with phi/sub e/ approx. = phi/sub max/(1-(r/32)/sup 2/) and 300 < phi/sub max/ <450 volts. With puffer-valve fueling, the space potential is relatively flat to at least 27 cm radius, with 250 < phi/sub e/ < 350 volts.

  1. Heavy metal geochemistry of the acid mine drainage discharged from the Hejiacun uranium mine in central Hunan, China

    NASA Astrophysics Data System (ADS)

    Peng, Bo; Tang, Xiaoyan; Yu, Changxun; Xie, Shurong; Xiao, Meilian; Song, Zhi; Tu, Xianglin

    2009-03-01

    The acid mine drainage (AMD) discharged from the Hejiacun uranium mine in central Hunan (China) was sampled and analyzed using ICP-MS techniques. The analyzing results show that the AMD is characterized by the major ions FeTotal, Mn, Al and Si, and is concentrated with heavy metals and metalloids including Cd, Co, Ni, Zn, U, Cu, Pb, Tl, V, Cr, Se, As and Sb. During the AMD flowing downstream, the dissolved heavy metals were removed from the AMD waters through adsorption onto and co-precipitation with metal-oxhydroxides coated on the streambed. Among these metals, Cd, Co, Ni, Zn, U, Cu, Pb and Tl are negatively correlated to pH values, and positively correlated to major ions Fe, Al, Si, Mn, Mg, Ca and K. The metals/metalloids V, Cr, Se, As and Sb are conservative in the AMD solution, and negatively-correlated to major ions Na, Ca and Mg. Due to the above different behaviors of these chemical elements, the pH-negatively related metals (PM) and the conservative metals (CM) are identified; the PM metals include Cd, Co, Ni, Zn, U, Cu, Pb and Tl, and the CM metals V, Cr, Se, As and Sb. Based on understanding the geochemistry of PM and CM metals in the AMD waters, a new equation: EXT = (Acidity + PM)/pH + CM × pH, is proposed to estimate and evaluate extent of heavy-metal pollution (EXT) of AMD. The evaluation results show that the AMD and surface waters of the mine area have high EXT values, and they could be the potential source of heavy-metal contamination of the surrounding environment. Therefore, it is suggested that both the AMD and surface waters should be treated before they are drained out of the mine district, for which the traditional dilution and neutralization methods can be applied to remove the PM metals from the AMD waters, and new techniques through reducing the pH value of the downstream AMD waters should be developed for removal of the CM metals.

  2. Nicotianamine synthase gene family as central components in heavy metal and phytohormone response in maize.

    PubMed

    Zhou, Mei-Liang; Qi, Lei-Peng; Pang, Jun-Feng; Zhang, Qian; Lei, Zhi; Tang, Yi-Xiong; Zhu, Xue-Mei; Shao, Ji-Rong; Wu, Yan-Min

    2013-06-01

    Nicotianamine (NA) is an important divalent metal chelator and the main precursor of phytosiderophores. NA is synthesized from S-adenosylmethionine in a process catalyzed by nicotianamine synthase (NAS). In this study, a set of structural and phylogenetic analyses have been applied to identify the maize NAS genes based on the maize genome sequence release. Ten maize NAS genes have been mapped; seven of them have not been reported to date. Phylogenetic analysis and expression pattern from microarray data led to their classification into two different orthologous groups. C-terminal fusion of ZmNAS3 with GFP was found in the cytoplasm of Arabidopsis leaf protoplast. Expression analysis by reverse transcription polymerase chain reaction revealed ZmNAS genes are responsive to heavy metal ions (Ni, Fe, Cu, Mn, Zn, and Cd), and all 10 ZmNAS genes were only observed in the root tissue except of ZmNAS6. The promoter of ZmNAS genes was analyzed for the presence of different cis-element response to all kinds of phytohormones and environment stresses. We found that the ZmNAS gene expression of maize seedlings was regulated by jasmonic acid, abscisic acid, and salicylic acid. Microarray data demonstrated that the ZmNAS genes show differential, organ-specific expression patterns in the maize developmental steps. The integrated comparative analysis can improve our current view of ZmNAS genes and facilitate the functional characterization of individual members.

  3. Numerical simulations of heavy rainfall over central Korea on 21 September 2010 using the WRF model

    NASA Astrophysics Data System (ADS)

    Byun, Ui-Yong; Hong, Jinkyu; Hong, Song-You; Shin, Hyeyum Hailey

    2015-06-01

    On 21 September 2010, heavy rainfall with a local maximum of 259 mm d-1 occurred near Seoul, South Korea. We examined the ability of the Weather Research and Forecasting (WRF) model in reproducing this disastrous rainfall event and identified the role of two physical processes: planetary boundary layer (PBL) and microphysics (MPS) processes. The WRF model was forced by 6-hourly National Centers for Environmental Prediction (NCEP) Final analysis (FNL) data for 36 hours form 1200 UTC 20 to 0000 UTC 22 September 2010. Twenty-five experiments were performed, consisting of five different PBL schemes—Yonsei University (YSU), Mellor-Yamada-Janjic (MYJ), Quasi Normal Scale Elimination (QNSE), Bougeault and Lacarrere (BouLac), and University of Washington (UW)—and five different MPS schemes—WRF Single-Moment 6-class (WSM6), Goddard, Thompson, Milbrandt 2-moments, and Morrison 2-moments. As expected, there was a specific combination of MPS and PBL schemes that showed good skill in forecasting the precipitation. However, there was no specific PBL or MPS scheme that outperformed the others in all aspects. The experiments with the UW PBL or Thompson MPS scheme showed a relatively small amount of precipitation. Analyses form the sensitivity experiments confirmed that the spatial distribution of the simulated precipitation was dominated by the PBL processes, whereas the MPS processes determined the amount of rainfall. It was also found that the temporal evolution of the precipitation was influenced more by the PBL processes than by the MPS processes.

  4. Relationships between soil heavy metal pollution and enzyme activities in mining areas of northern Hunan province, Central South China

    NASA Astrophysics Data System (ADS)

    Hu, Xue-Feng; Jiang, Ying; Shu, Ying

    2014-05-01

    Hunan province, Central South China, is a well-known nonferrous metal base in China. Mine exploiting and processing there, however, often lead to heavy metal pollution of farmland. To study the effects of mining activities on the soil environmental quality, four representative paddy fields, the HSG, SNJ, NT and THJ, in Y county, northern Hunan province, were investigated. It was found that the streams running through the HSG, SNJ and NT are severely contaminated due to the long-term discharge of untreated mineral wastewater from local indigenous mining factories. The stream at the HSG, for example, is brownish red in color, with high concentrations of Cu, Zn, Cd, Fe and Mn. The concentrations of Cu, Zn and Cd in all the stream water of the HSG, SNJ and NT exceed the maximum allowable levels of the Agricultural Irrigation Water Criteria of China. Correspondingly, the HSG, SNJ and NT are heavily polluted by Cu, Zn and Cd due to the long-term irrigation with the contaminated stream water. In comparison, both stream water and paddy fields of the THJ, far away from mining areas, are not contaminated by any heavy metals and hence regarded as a control in this study. The rice grain produced at the HSG, SNJ and NT has a high risk of Cd contamination. The rate of rice grain produced in the four paddy fields in Y county with Cd exceeding the safe level (Cd, 0.2 μg g-1) specified by the National Standards for Rice Quality and Safety of China reaches 90%. Cd content in the rice grain is positively significantly correlated with that in the paddy fields, especially with the content of diethylenetriaminepentaacetic acid (DTPA) - extracted Cd, suggesting that the heavy metal pollution of paddy fields has already posed a high risk to rice safety and human health. Soil enzyme activities and microbial biomass are significantly inhibited by the heavy metal pollution of the paddy fields. Microbial biomass C and N (MBC and MBN) at a severely contaminated site of the HSG are only 31

  5. Intermediate mass fragment production in central collisions of intermediate energy heavy ions

    SciTech Connect

    Li, T.; Bauer, W.; Craig, D.; Cronqvist, M.; Gualtieri, E.; Hannuschke, S.; Lacey, R.; Llope, W.J.; Reposeur, T.; Vander Molen, A.M.; Westfall, G.D.; Wilson, W.K.; Winfield, J.S.; Yee, J.; Yennello, S.J. ); Nadasen, A. ); Tickle, R.S. ); Norbeck, E. )

    1993-03-29

    We present [ital Z] distributions for fragments with 1[le][ital Z][le]12 from central collisions of [sup 40] Ar+[sup 45]Sc at incident energies ranging from 35 to 115 MeV/nucleon. We find that the [ital Z] distributions can be described by a power law or an exponential and steepen with increasing incident energy. Over the range of incident energies studied, the average number of intermediate mass fragments decreases while the average number of particles increases. When combined with previous results for the charge distributions, a minimum is observed in the extracted power-law parameter.

  6. Assessment of human exposure to environmental heavy metals in soils and bryophytes of the central region of Portugal.

    PubMed

    Reis, Amélia Paula; Patinha, Carla; Ferreira da Silva, Eduardo; Sousa, António; Figueira, Rui; Sérgio, Cecilia; Novais, Vera

    2010-04-01

    This study intends to identify the spatial patterns of variation for some metals and metalloids, in soils and mosses, in the central region of Portugal. The purposes were: (i) to identify relationships amongst five elements (Cu, Pb, Zn, Cr and As) in three different media (topsoil, bottom soil and bryophytes) and with some site-specific characteristics, using Multiple Correspondence Analysis; (ii) to define spatial patterns of variation for the associations identified by Multiple Correspondence Analysis using Variography and Ordinary Kriging; and (iii) to assess atmospheric deposition as a source of heavy metals to the topsoil by crossing results with the biomonitors. The results indicated relatively low metal concentrations in soils and mosses. Some metal associations and dissociations were identified. The spatial patterns of variation of bottom and topsoil are distinct. There is some evidence that different site-specific characteristics control the spatial distribution of different elements. The areas within the central region of Portugal with a higher vulnerability to metal contamination were identified.

  7. Combining a finite mixture distribution model with indicator kriging to delineate and map the spatial patterns of soil heavy metal pollution in Chunghua County, central Taiwan.

    PubMed

    Lin, Yu-Pin; Cheng, Bai-You; Shyu, Guey-Shin; Chang, Tsun-Kuo

    2010-01-01

    This study identifies the natural background, anthropogenic background and distribution of contamination caused by heavy metal pollutants in soil in Chunghua County of central Taiwan by using a finite mixture distribution model (FMDM). The probabilities of contaminated area distribution are mapped using single-variable indicator kriging and multiple-variable indicator kriging (MVIK) with the FMDM cut-off values and regulation thresholds for heavy metals. FMDM results indicate that Cr, Cu, Ni and Zn can be individually fitted by a mixture model representing the background and contamination distributions of the four metals in soil. The FMDM cut-off values for contamination caused by the metals are close to the regulation thresholds, except for the cut-off value of Zn. The receiver operating characteristic (ROC) curve validates that indicator kriging and MVIK with FMDM cut-off values can reliably delineate heavy metals contamination, particularly for areas lacking background information and high heavy metal concentrations in soil.

  8. Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of the central zinc-binding domain of the human Mcm10 DNA-replication factor.

    PubMed

    Jung, Nam Young; Bae, Won Jin; Chang, Jeong Ho; Kim, Young Chang; Cho, Yunje

    2008-06-01

    The initiation of eukaryotic DNA replication requires the tightly controlled assembly of a set of replication factors. Mcm10 is a highly conserved nuclear protein that plays a key role in the initiation and elongation processes of DNA replication by providing a physical link between the Mcm2-7 complex and DNA polymerases. The central domain, which contains the CCCH zinc-binding motif, is most conserved within Mcm10 and binds to DNA and several proteins, including proliferative cell nuclear antigen. In this study, the central domain of human Mcm10 was crystallized using the hanging-drop vapour-diffusion method in the presence of PEG 3350. An X-ray diffraction data set was collected to a resolution of 2.6 A on a synchrotron beamline. The crystals formed belonged to space group R3, with unit-cell parameters a = b = 99.5, c = 133.0 A. According to Matthews coefficient calculations, the crystals were predicted to contain six MCM10 central domain molecules in the asymmetric unit.

  9. The Adverse Effects of Heavy Metals with and without Noise Exposure on the Human Peripheral and Central Auditory System: A Literature Review.

    PubMed

    Castellanos, Marie-Josée; Fuente, Adrian

    2016-12-09

    Exposure to some chemicals in the workplace can lead to occupational chemical-induced hearing loss. Attention has mainly focused on the adverse auditory effects of solvents. However, other chemicals such as heavy metals have been also identified as ototoxic agents. The aim of this work was to review the current scientific knowledge about the adverse auditory effects of heavy metal exposure with and without co-exposure to noise in humans. PubMed and Medline were accessed to find suitable articles. A total of 49 articles met the inclusion criteria. Results from the review showed that no evidence about the ototoxic effects in humans of manganese is available. Contradictory results have been found for arsenic, lead and mercury as well as for the possible interaction between heavy metals and noise. All studies found in this review have found that exposure to cadmium and mixtures of heavy metals induce auditory dysfunction. Most of the studies investigating the adverse auditory effects of heavy metals in humans have investigated human populations exposed to lead. Some of these studies suggest peripheral and central auditory dysfunction induced by lead exposure. It is concluded that further evidence from human studies about the adverse auditory effects of heavy metal exposure is still required. Despite this issue, audiologists and other hearing health care professionals should be aware of the possible auditory effects of heavy metals.

  10. The Adverse Effects of Heavy Metals with and without Noise Exposure on the Human Peripheral and Central Auditory System: A Literature Review

    PubMed Central

    Castellanos, Marie-Josée; Fuente, Adrian

    2016-01-01

    Exposure to some chemicals in the workplace can lead to occupational chemical-induced hearing loss. Attention has mainly focused on the adverse auditory effects of solvents. However, other chemicals such as heavy metals have been also identified as ototoxic agents. The aim of this work was to review the current scientific knowledge about the adverse auditory effects of heavy metal exposure with and without co-exposure to noise in humans. PubMed and Medline were accessed to find suitable articles. A total of 49 articles met the inclusion criteria. Results from the review showed that no evidence about the ototoxic effects in humans of manganese is available. Contradictory results have been found for arsenic, lead and mercury as well as for the possible interaction between heavy metals and noise. All studies found in this review have found that exposure to cadmium and mixtures of heavy metals induce auditory dysfunction. Most of the studies investigating the adverse auditory effects of heavy metals in humans have investigated human populations exposed to lead. Some of these studies suggest peripheral and central auditory dysfunction induced by lead exposure. It is concluded that further evidence from human studies about the adverse auditory effects of heavy metal exposure is still required. Despite this issue, audiologists and other hearing health care professionals should be aware of the possible auditory effects of heavy metals. PMID:27941700

  11. Analysis of diatomite sediments from a paleolake in central Mexico using PIXE, X-ray tomography and X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Miranda, J.; Oliver, A.; Vilaclara, G.; Rico-Montiel, R.; Macías, V. M.; Ruvalcaba, J. L.; Zenteno, M. A.

    1994-03-01

    Diatomite samples from paleolake Tlaxcala, in Central Mexico, have been analyzed using proton induced X-ray emission (PIXE), X-ray tomography and X-ray diffraction. Chiseled blocks were scanned with a 0.7 MeV proton beam, 0.1 mm in diameter, in 0.25 mm steps across the sediments. X-ray tomography with the same step sizes was then applied, in order to compare the concentrations obtained with PIXE and the material density in the sediment layers. Three different kinds of layers were found, related to their colors: dark, white and gray. The composition of the layers is fairly uniform. The dark zone is enriched in Al, K, Ca, Ti, Mn, and Fe. This dark layer may be associated with eruptions of the Malitzin volcano. The white zone is found to contain diatomite of a high purity, with traces of K, Ca, and Fe, while the gray zones are also Al enriched, suggesting a clay contamination of the diatomite. X-ray diffraction of materials obtained from each main layer showed that the white and gray phases are highly amorphous, with a small component of cristobalite, as expected from the diatom sediment diagenesis, while the dark layer contains also important amounts of anorthite and orthoclase, supporting the volcanic origin of this layer.

  12. Central production of ρ0 in p p collisions with single proton diffractive dissociation at the LHC

    NASA Astrophysics Data System (ADS)

    Lebiedowicz, Piotr; Nachtmann, Otto; Szczurek, Antoni

    2017-02-01

    We consider the p p →p p ρ0π0 and p p →p n ρ0π+ processes at LHC energies. Our description is based on the nonperturbative framework of tensor pomeron and tensor reggeon exchanges. We discuss the Drell-Hiida-Deck type mechanism with centrally produced ρ0 meson associated with a very forward/backward π N system. The considered processes constitute an inelastic (nonexclusive) background to the p p →p p ρ0 reaction in the case when only the centrally produced ρ0 meson decaying into π+π- is measured, the final state protons are not observed, and only rapidity-gap conditions are checked experimentally. We compare our results for the γ π+→ρ0π+ reaction with the experimental data obtained by the H1 collaboration at HERA. We present several differential distributions for the p p →p n ρ0π+ reaction and estimate the size of the proton dissociative background to the exclusive p p →p p ρ0 process. The ratio of integrated cross sections for the inelastic p p →p N ρ0π processes, where p N ρ0π stands for p n ρ0π+ plus p p ρ0π0, to the reference reaction p p →p p ρ0 is of order of (7-10)%. We present also the ratios of the ρ0 rapidity and transverse momentum distributions for the inelastic p p →p N ρ0π versus the elastic p p →p p ρ0 reaction. Our results may be used to investigate the γ π →ρ0π process at LHC energies.

  13. Historical trends of dioxin-like compounds and heavy metals in sediments buried in a reservoir in central Taiwan.

    PubMed

    Chi, Kai Hsien; Luo, Shangde; Hsu, Shih Chieh; Kao, Shuh Ji; Tsai, Yu Jung; Chang, Moo Been

    2009-06-01

    Polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), polychlorinated biphenyl (PCB) and heavy metal concentrations were analyzed at 1-2 cm intervals in a sediment core collected from a reservoir to evaluate anthropogenic pollution history in central Taiwan. The age of the sediment core was estimated from the sedimentation rate (0.44-0.52 cm year(-1), calculated by (210)Pb and (137)Cs analysis). The highest PCDD/F (4.10 ng TEQ(WHO)kg(-1)d.w.) and PCB (0.345ngTEQ(WHO)kg(-1)d.w.) concentrations occurred around 1985 (i.e. at a downcore depth of 10-12 cm). Our results also demonstrated that PCDD/F and PCB concentrations in the reservoir sediment core started to decrease at a depth of 8-10 cm (estimated year: 1989). This may be attributed to the fact that the Taiwan Environmental Protection Administration (EPA) proposed the regulation of pentachlorophenol (PCP) production and PCB manufacture in 1983 and 1988, respectively. In addition, a linear increasing trend in metal content with time (towards the core top) was observed for several metals (Zn, Cr, Cu, Cd and Pb). Results of the enrichments rates of anthropogenic metals indicated that the metal/alumina (M/Al) ratios of Zn, Cd and Pb in sediment cores exceeded those in crust compositions by 47%, 59% and 78%, respectively. The results revealed that considerable amounts of heavy metals were carried into the reservoir following significant immigration during the Chinese civil war (1950).

  14. Dispersion of As and selected heavy metals around a coal-burning power station in central Slovakia.

    PubMed

    Keegan, T J; Farago, M E; Thornton, I; Hong, Bing; Colvile, R N; Pesch, B; Jakubis, P; Nieuwenhuijsen, M J

    2006-04-01

    A power station in central Slovakia emitted arsenic (As) in large quantities for over 30 years as a result of burning As-rich brown coal. Nowadays emissions of As are low. Over the lifetime of the plant's operation over 3000 tonne of As have been emitted into the environment. This paper aims to examine the concentrations of As in the soil around the power station, and also to investigate whether the coal burnt in the plant, and consequently the emissions from it, contained raised levels of six further heavy metals. Soil concentrations were compared to ground level air As concentrations predicted by an air dispersion model. Coal samples were taken from the power station and analysed to determine concentrations of As, Zn, Pb, Cu, Cr, Ni and Cd. Soil samples (n=113) were taken up to 12 km from the plant along a transect designed to follow the valley floor in which the power station is situated. Soil samples were analysed for concentrations of those elements for which coal was tested. Concentrations of As in coal were high (AM 518 mug/g). Those of other heavy metals were, in general, low. Concentrations of soil As were substantially raised in the near vicinity of the plant but decreased within 5 km to concentrations similar to those in the rest of the district. Overall, levels within 10 km of the plant were slightly above those recommended for residential levels in the UK. Soil concentrations of other heavy metals were higher in the vicinity of the plant but none, overall was raised. Comparison of results from a previous air dispersion model of ground level air arsenic concentrations showed a moderate correlation (r=0.6) between modelled and measured values. Over its period of operation the power plant has contributed to raised levels of soil As in the local soils, though not substantially of other elements. Though now airborne As emissions are controlled, concern remains regarding soil arsenic concentrations and fugitive emissions from the plant that could be

  15. NMR imaging and spectroscopy of the mammalian central nervous system after heavy ion radiation

    SciTech Connect

    Richards, T.

    1984-09-01

    NMR imaging, NMR spectroscopic, and histopathologic techniques were used to study the proton relaxation time and related biochemical changes in the central nervous system after helium beam in vivo irradiation of the rodent brain. The spectroscopic observations reported in this dissertation were made possible by development of methods for measuring the NMR parameters of the rodent brain in vivo and in vitro. The methods include (1) depth selective spectroscopy using an optimization of rf pulse energy based on a priori knowledge of N-acetyl aspartate and lipid spectra of the normal brain, (2) phase-encoded proton spectroscopy of the living rodent using a surface coil, and (3) dual aqueous and organic tissue extraction technique for spectroscopy. Radiation induced increases were observed in lipid and p-choline peaks of the proton spectrum, in vivo. Proton NMR spectroscopy measurements on brain extracts (aqueous and organic solvents) were made to observe chemical changes that could not be seen in vivo. Radiation-induced changes were observed in lactate, GABA, glutamate, and p-choline peak areas of the aqueous fraction spectra. In the organic fraction, decreases were observed in peak area ratios of the terminal-methyl peaks, the N-methyl groups of choline, and at a peak at 2.84 ppM (phosphatidyl ethanolamine and phosphatidyl serine resonances) relative to TMS. With histology and Evans blue injections, blood-brain barrier alternations were seen as early as 4 days after irradiation. 83 references, 53 figures.

  16. Concentrations of Heavy Metals in Commercially Important Oysters from Goa, Central-West Coast of India.

    PubMed

    Shenai-Tirodkar, Prachi S; Gauns, Mangesh U; Ansari, Zakir A

    2016-12-01

    The major beds of oyster along the central-west coast of India are exposed to different anthropogenic activities and are severely exploited for human consumption. In this viewpoint, tissues of oyster Crassostrea madrasensis, C. gryphoides and Saccostrea cucullata were analyzed for Cu, Ni, Cd and Pb concentrations (dry weight) from Chicalim Bay, Nerul Creek and Chapora Bay in pre-monsoon, monsoon and post-monsoon seasons. A higher concentration of Cu (134.4-2167.9 mg kg(-1)) and Cd (7.1-88.5 mg kg(-1)) was found, which is greater than the recommended limits in all the three species (and sites). Moreover, significant (p < 0.05) variations were observed for all the metals concentrations among the species, seasons and sites. The high concentrations of Cd and Cu in tissues of edible oyster pose a threat to human health. Therefore, continuous monitoring, people awareness and a stringent government policy should be implemented to mitigate the metal pollution along the studied sites.

  17. Availability of geogenic heavy metals in soils of Thiva town (central Greece).

    PubMed

    Kelepertzis, Efstratios; Stathopoulou, Eleni

    2013-11-01

    Potentially toxic metals in the urban chemical environment impose risks to both ecosystem and human health. Here, we evaluate the labile pools and availabilities of non-anthropogenic Ni, Cr, Co and Mn in soil samples from Thiva town (central Greece) and investigate their associations with common soil properties and geochemical data obtained by the aqua regia and single selective dissolutions. Experimental work included the initial application of the sequential extraction protocol proposed by the European Community Bureau of Reference and chemical extractions with ethylenediamine tetraacetic acid solution and a modified physiologically based extraction test with the aim to obtain the operationally defined fractions of plant availability and human bioaccessibility, respectively. The leachate results demonstrated that despite the significant contribution of residual metal species especially for Ni and Cr, the studied serpentine soils provide chemically labile pools for all the considered elements. Nickel was found to be the most available metal with the order being Ni > Cr ∼ Co ∼ Mn for plant uptake and Ni > Cr > Co ∼ Mn for human bioaccessibility. The aqua regia extractable concentrations are not predictors of elemental availabilities except for Ni bioaccessible data interpreting however only a moderate percentage of the total variance. The incorporation of basic soil properties (mostly total organic carbon), geochemical data for the major elements Ca, Mg and Fe and ammonium oxalate extractable Cr significantly improved the estimations for individual elements entailing the strong influence of the chemistry and mineralogy of soil materials to the release of focus metals from the soil matrix. This study provides for the first time bioaccessible data for serpentine-derived soils that are more realistic for evaluating potential adverse effects on the human health.

  18. Increasing heavy metals in the background atmosphere of central North China since the 1980s: Evidence from a 200-year lake sediment record

    NASA Astrophysics Data System (ADS)

    Wan, Dejun; Song, Lei; Yang, Jinsong; Jin, Zhangdong; Zhan, Changlin; Mao, Xin; Liu, Dongwei; Shao, Yue

    2016-08-01

    Long-term trends of atmospheric compositions are significant for assessing the influence of human activities on the atmosphere and protecting the atmospheric environment. In this study, based on heavy metal concentrations and Pb isotope ratios in a well-dated sediment core from a remote alpine lake in central North China, anthropogenic fluxes of As, Cd, Sb, and Pb were reconstructed and heavy metal evolutions in the atmosphere were revealed in the last 200 years. The heavy metals in the atmosphere were generally natural origins before 1980 A.D. Since the 1980s they began to increase gradually, but they increased the most in the 1990s resulting from rapid developments of rough and high energy-consuming industries in North China. After entering the 21st century the industries still developed rapidly, but the atmospheric Pb ceased increase and the As and Sb even decreased in the 2000s due to (1) phasing out of leaded gasoline and (2) implementing stricter industrial emission standards in 2000 A.D. in China. However, in the 2000s the atmospheric heavy metals still kept at a relatively high level and even likely began to increase again in the 2010s. Considering the lake relatively remote and seldom affected by local human activities, the results likely reflect heavy metal evolutions in the regional background atmosphere of central North China at the annual/decadal timescale in the last 200 years.

  19. Moderate-Heavy Alcohol Consumption Lifestyle in Older Adults Is Associated with Altered Central Executive Network Community Structure during Cognitive Task

    PubMed Central

    Moussa, Malaak N.; Simpson, Sean L.; Lyday, Robert G.; Burdette, Jonathan H.; Porrino, Linda J.; Laurienti, Paul J.

    2016-01-01

    Older adults today consume more alcohol than previous generations, the majority being social drinkers. The effects of heavy alcohol use on brain functioning closely resemble age-related changes, but it is not known if moderate-heavy alcohol consumption intensifies brain aging. Whether a lifestyle of moderate-heavy alcohol use in older adults increased age-related brain changes was examined. Forty-one older adults (65–80 years) that consumed light (< 2 drinks/week and ≥ 1 drink/month, n = 20) or moderate-heavy (7–21 drinks/week, non-bingers, n = 21) amounts of alcohol were enrolled. Twenty-two young adults (24–35 years) were also enrolled (light, n = 11 and moderate-heavy, n = 11). Functional brain networks based on magnetic resonance imaging data were generated for resting state and during a working memory task. Whole-brain, Central Executive Network (CEN), and Default Mode Network (DMN) connectivity were assessed in light and moderate-heavy alcohol consuming older adults with comparisons to young adults. The older adults had significantly lower whole brain connectivity (global efficiency) and lower regional connectivity (community structure) in the CEN during task and in the DMN at rest. Moderate-heavy older drinkers did not exhibit whole brain connectivity differences compared to the low drinkers. However, decreased CEN connectivity was observed during the task. There were no differences in the DMN connectivity between drinking groups. Taken together, a lifestyle including moderate-heavy alcohol consumption may be associated with further decreases in brain network connectivity within task-related networks in older adults. Further research is required to determine if this decrease is compensatory or an early sign of decline. PMID:27494180

  20. Moderate-Heavy Alcohol Consumption Lifestyle in Older Adults Is Associated with Altered Central Executive Network Community Structure during Cognitive Task.

    PubMed

    Mayhugh, Rhiannon E; Moussa, Malaak N; Simpson, Sean L; Lyday, Robert G; Burdette, Jonathan H; Porrino, Linda J; Laurienti, Paul J

    2016-01-01

    Older adults today consume more alcohol than previous generations, the majority being social drinkers. The effects of heavy alcohol use on brain functioning closely resemble age-related changes, but it is not known if moderate-heavy alcohol consumption intensifies brain aging. Whether a lifestyle of moderate-heavy alcohol use in older adults increased age-related brain changes was examined. Forty-one older adults (65-80 years) that consumed light (< 2 drinks/week and ≥ 1 drink/month, n = 20) or moderate-heavy (7-21 drinks/week, non-bingers, n = 21) amounts of alcohol were enrolled. Twenty-two young adults (24-35 years) were also enrolled (light, n = 11 and moderate-heavy, n = 11). Functional brain networks based on magnetic resonance imaging data were generated for resting state and during a working memory task. Whole-brain, Central Executive Network (CEN), and Default Mode Network (DMN) connectivity were assessed in light and moderate-heavy alcohol consuming older adults with comparisons to young adults. The older adults had significantly lower whole brain connectivity (global efficiency) and lower regional connectivity (community structure) in the CEN during task and in the DMN at rest. Moderate-heavy older drinkers did not exhibit whole brain connectivity differences compared to the low drinkers. However, decreased CEN connectivity was observed during the task. There were no differences in the DMN connectivity between drinking groups. Taken together, a lifestyle including moderate-heavy alcohol consumption may be associated with further decreases in brain network connectivity within task-related networks in older adults. Further research is required to determine if this decrease is compensatory or an early sign of decline.

  1. Centrality dependence of identified particle elliptic flow in relativistic heavy ion collisions at √{sN N}=7.7 -62.4 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Chisman, O.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, H. Z.; Huang, B.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, Y.; Li, W.; Li, C.; Li, X.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, Y. G.; Ma, G. L.; Ma, R.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X.; Sun, Z.; Sun, Y.; Sun, X. M.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, Y.; Wang, G.; Wang, Y.; Wang, J. S.; Wang, H.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Z.; Xu, H.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Y.; Zhang, S.; Zhang, J.; Zhang, J.; Zhang, Z.; Zhang, X. P.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-01-01

    Elliptic flow (v2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √{sN N}= 7.7 -62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √{sN N}= 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v2 for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.

  2. Centrality dependence of identified particle elliptic flow in relativistic heavy ion collisions at sNN=7.7–62.4 GeV

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2016-01-19

    Here, elliptic flow (v2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √sNN = 7.7–62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √sNN = 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v2 for most particles relative to antiparticles, already observed for minimum bias collisions, showsmore » a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.« less

  3. Development of heavy mineral and heavy element database of soil sediments in Japan using synchrotron radiation X-ray powder diffraction and high-energy (116 keV) X-ray fluorescence analysis: 1. Case study of Kofu and Chiba region.

    PubMed

    Bong, Willy Shun Kai; Nakai, Izumi; Furuya, Shunsuke; Suzuki, Hiroko; Abe, Yoshinari; Osaka, Keiichi; Matsumoto, Takuya; Itou, Masayoshi; Imai, Noboru; Ninomiya, Toshio

    2012-07-10

    We have started the construction of a nationwide forensic soil sediment database for Japan based on the heavy mineral and trace heavy element compositions of stream sediments collected at 3024 points all over Japan obtained by high-resolution synchrotron X-ray powder diffraction (SR-XRD) and high-energy synchrotron X-ray fluorescence analysis (HE-SR-XRF). In this study, the performance of both techniques was demonstrated by analyzing soil sediments from two different geological regions, the Kofu and Chiba regions in Kanto province, to construct database that can be applied in the future to provenance analysis of soil evidence from a crime scene. The sediments from the quaternary volcanic lithology of the Chiba region were found to be dominated by heavy minerals of volcanic origin - orthopyroxene, clinopyroxene, and amphibole, and the REEs (rare earth elements) within the region showed similar geochemical behavior. On the other hand, four distinct heavy mineral groups were identified in the sediments of the Kofu region, where there is a great variety of underlying bedrock, and the geochemical behavior of the REEs in the sediments also varied accordingly to their geological origins. As such, our study shows that high-resolution SR-XRD data can provide information on the spatial distribution patterns of heavy minerals in stream sediments, playing an important role in determining their likely geographical origin. Meanwhile, the highly sensitive HE-SR-XRF data allow us to study the geochemical behavior of trace heavy elements, especially the REEs in the sediments, providing additional support to further constrain the likely geographical origin of the sediments determined by heavy minerals.

  4. Phytoremedial assessment of flora tolerant to heavy metals in the contaminated soils of an abandoned Pb mine in Central Portugal.

    PubMed

    Pratas, João; Favas, Paulo J C; D'Souza, Rohan; Varun, Mayank; Paul, Manoj S

    2013-02-01

    Significant accumulation of heavy metals in soils and flora exists around the abandoned Barbadalhos Pb mine in Central Portugal. Soil and plant samples [49 species] were collected from two line transects, LT 1 and LT 2, in the mineralized and non-mineralized area, respectively to gain a comprehensive picture of heavy metals in soils and flora to assess its potential for phytoremediation. Phytosociological inventories of the vegetation were made using the Braun-Blanquet cover-abundance scale. Metal concentrations in soil ranged from (in mg kg(-1)): 98-9330 [Pb], 110-517 [Zn], 7.1-50 [Co], 69-123 [Cr], 31-193 [Cu], 33400-98500 [Fe], 7.7-51 [Ni], 0.95-13 [Ag], 2.8-208 [As], and 71-2220 [Mn] along LT 1; and 24-93 [Pb], 30-162 [Zn], 3.7-34 [Co], 61-196 [Cr], 21-46 [Cu], 24100-59400 [Fe], 17-87 [Ni], 0.71-1.9 [Ag], 4.3-12 [As], and 44-1800 [Mn] along LT 2. Plant metal content ranged from (in mg kg(-1)): 1.11-548 [Pb], 7.06-1020 [Zn], 0.08-2.09 [Co], 0.09-2.03 [Cr], 2.63-38.5 [Cu], 10.4-4450 [Fe], 0.38-8.9 [Ni], and 0.03-1.9 [Ag] along LT 1; and 0.94-11.58 [Pb], 2.83-96.5 [Zn], 0.12-1.44 [Co], 0.21-1.49 [Cr], 1.61-22.7 [Cu], 4.6-2050 [Fe], 0.51-4.81 [Ni], and 0.02-0.31 [Ag] along LT 2. Plants with highest uptake of metals were: Cistus salvifolius (548 mg Pb kg(-1)), Digitalis purpurea (1017 mg Zn kg(-1) and 4450 mg Fe kg(-1)). Mentha suavolens and Ruscus ulmifolius were seen to hyperaccumulate Ag (1.9 and 1 mg Ag kg(-1), respectively). More metals and higher concentrations were traced in plants from LT 1, especially for Pb and Zn. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. On the use of Cox regression to examine the temporal clustering of flooding and heavy precipitation across the central United States

    NASA Astrophysics Data System (ADS)

    Mallakpour, Iman; Villarini, Gabriele; Jones, Michael P.; Smith, James A.

    2017-08-01

    The central United States is plagued by frequent catastrophic flooding, such as the flood events of 1993, 2008, 2011, 2013, 2014 and 2016. The goal of this study is to examine whether it is possible to describe the occurrence of flood and heavy precipitation events at the sub-seasonal scale in terms of variations in the climate system. Daily streamflow and precipitation time series over the central United States (defined here to include North Dakota, South Dakota, Nebraska, Kansas, Missouri, Iowa, Minnesota, Wisconsin, Illinois, West Virginia, Kentucky, Ohio, Indiana, and Michigan) are used in this study. We model the occurrence/non-occurrence of a flood and heavy precipitation event over time using regression models based on Cox processes, which can be viewed as a generalization of Poisson processes. Rather than assuming that an event (i.e., flooding or precipitation) occurs independently of the occurrence of the previous one (as in Poisson processes), Cox processes allow us to account for the potential presence of temporal clustering, which manifests itself in an alternation of quiet and active periods. Here we model the occurrence/non-occurrence of flood and heavy precipitation events using two climate indices as time-varying covariates: the Arctic Oscillation (AO) and the Pacific-North American pattern (PNA). We find that AO and/or PNA are important predictors in explaining the temporal clustering in flood occurrences in over 78% of the stream gages we considered. Similar results are obtained when working with heavy precipitation events. Analyses of the sensitivity of the results to different thresholds used to identify events lead to the same conclusions. The findings of this work highlight that variations in the climate system play a critical role in explaining the occurrence of flood and heavy precipitation events at the sub-seasonal scale over the central United States.

  6. Centrality and energy dependence of charged-particle multiplicities in heavy ion collisions in the context of elementary reactions

    SciTech Connect

    Back, B. B.; Wuosmaa, A. H.; Baker, M. D.; Barton, D. S.; Carroll, A.; Gushue, S.; Heintzelman, G. A.; Holzman, B.; Pak, R.; Remsberg, L. P.; Steinberg, P.; Sukhanov, A.; Betts, R. R.; Garcia, E.; Halliwell, C.; Hofman, D. J.; Hollis, R. S.; Iordanova, A.; Kucewicz, W.; McLeod, D.

    2006-08-15

    The PHOBOS experiment at the BNL Relativistic Heavy Ion Collider has measured the total multiplicity of primary charged particles as a function of collision centrality in Au+Au collisions at {radical}(s{sub NN})= 19.6, 130, and 200 GeV. An approximate independence of / on the number of participating nucleons is observed, reminiscent of 'wounded nucleon' scaling (N{sub ch}{proportional_to}N{sub part}) observed in proton-nucleus collisions. Unlike p+A, the constant of proportionality does not seem to be set by the pp/pp data at the same energy. Rather, there seems to be a surprising correspondence with the total multiplicity measured in e{sup +}e{sup -} annihilations, as well as the rapidity shape measured over a large range. The energy dependence of the integrated multiplicity per participant pair shows that e{sup +}e{sup -} and A+A data agree over a large range of center-of-mass energies ({radical}(s)>20 GeV), and pp/pp data can be brought to agree approximately with the e{sup +}e{sup -} data by correcting for the typical energy taken away by leading particles. This is suggestive of a mechanism for soft particle production that depends mainly on the amount of available energy. It is conjectured that the dominant distinction between A+A and p+p collisions is the multiple collisions per participant, which appears to be sufficient to substantially reduce the energy taken away by leading particles.

  7. Isotopically (δ13C and δ18O) heavy volcanic plumes from Central Andean volcanoes: a field study

    NASA Astrophysics Data System (ADS)

    Schipper, C. Ian; Moussallam, Yves; Curtis, Aaron; Peters, Nial; Barnie, Talfan; Bani, Philipson; Jost, H. J.; Hamilton, Doug; Aiuppa, Alessandro; Tamburello, Giancarlo; Giudice, Gaetano

    2017-08-01

    Stable isotopes of carbon and oxygen in volcanic gases are key tracers of volatile transfer between Earth's interior and atmosphere. Although important, these data are available for few volcanoes because they have traditionally been difficult to obtain and are usually measured on gas samples collected from fumaroles. We present new field measurements of bulk plume composition and stable isotopes (δ13CCO2 and δ18OH2O+CO2) carried out at three northern Chilean volcanoes using MultiGAS and isotope ratio infrared spectroscopy. Carbon and oxygen in magmatic gas plumes of Lastarria and Isluga volcanoes have δ13C in CO2 of +0.76‰ to +0.77‰ (VPDB), similar to slab carbonate; and δ18O in the H2O + CO2 system ranging from +12.2‰ to +20.7‰ (VSMOW), suggesting significant contributions from altered slab pore water and carbonate. The hydrothermal plume at Tacora has lower δ13CCO2 of -3.2‰ and δ18OH2O+CO2 of +7.0‰, reflecting various scrubbing, kinetic fractionation, and contamination processes. We show the isotopic characterization of volcanic gases in the field to be a practical complement to traditional sampling methods, with the potential to remove sampling bias that is a risk when only a few samples from accessible fumaroles are used to characterize a given volcano's volatile output. Our results indicate that there is a previously unrecognized, relatively heavy isotopic signature to bulk volcanic gas plumes in the Central Andes, which can be attributed to a strong influence from components of the subducting slab, but may also reflect some local crustal contamination. The techniques we describe open new avenues for quantifying the roles that subduction zones and arc volcanoes play in the global carbon cycle.

  8. Effect of Pressure on Valence and Structural Properties of YbFe 2 Ge 2 Heavy Fermion Compound—A Combined Inelastic X-ray Spectroscopy, X-ray Diffraction, and Theoretical Investigation

    DOE PAGES

    Kumar, Ravhi S.; Svane, Axel; Vaitheeswaran, Ganapathy; ...

    2015-10-19

    We measured the crystal structure and the Yb valence of the YbFe2Ge2 heavy fermion compound at room temperature and under high pressures using high-pressure powder X-ray diffraction and X-ray absorption spectroscopy via both partial fluorescence yield and resonant inelastic X-ray emission techniques. Moreover, the measurements are complemented by first-principles density functional theoretical calculations using the self-interaction corrected local spin density approximation investigating in particular the magnetic structure and the Yb valence. Finally, while the ThCr2Si2-type tetragonal (I4/mmm) structure is stable up to 53 GPa, the X-ray emission results show an increase of the Yb valence from v = 2.72(2) atmore » ambient pressure to v = 2.93(3) at ~9 GPa, where at low temperature a pressure-induced quantum critical state was reported.« less

  9. Effect of Pressure on Valence and Structural Properties of YbFe2Ge2 Heavy Fermion Compound A Combined Inelastic X-ray Spectroscopy, X-ray Diffraction, and Theoretical Investigation

    SciTech Connect

    Kumar, Ravhi S.; Svane, Axel; Vaitheeswaran, Ganapathy; Kanchana, Venkatakrishnan; Antonio, Daniel; Cornelius, Andrew L.; Bauer, Eric D.; Xiao, Yuming; Chow, Paul

    2016-06-03

    The crystal structure and the Yb valence of the YbFe2Ge2 heavy fermion compound was measured at room temperature and under high pressures using high-pressure powder X-ray diffraction and X-ray absorption spectroscopy via both partial fluorescence yield and resonant inelastic X-ray emission techniques. Furthermore, the measurements are complemented by first-principles density functional theoretical calculations using the self-interaction corrected local spin density approximation investigating in particular the magnetic structure and the Yb valence. While the ThCr2Si2-type tetragonal (I4/mmm) structure is stable up to 53 GPa, the X-ray emission results show an increase of the Yb valence from v = 2.72(2) at ambient pressure to v = 2.93(3) at ~9 GPa, where at low temperature a pressure-induced quantum critical state was reported.

  10. Effect of Pressure on Valence and Structural Properties of YbFe2Ge2 Heavy Fermion Compound--A Combined Inelastic X-ray Spectroscopy, X-ray Diffraction, and Theoretical Investigation.

    PubMed

    Kumar, Ravhi S; Svane, Axel; Vaitheeswaran, Ganapathy; Kanchana, Venkatakrishnan; Antonio, Daniel; Cornelius, Andrew L; Bauer, Eric D; Xiao, Yuming; Chow, Paul

    2015-11-02

    The crystal structure and the Yb valence of the YbFe2Ge2 heavy fermion compound was measured at room temperature and under high pressures using high-pressure powder X-ray diffraction and X-ray absorption spectroscopy via both partial fluorescence yield and resonant inelastic X-ray emission techniques. The measurements are complemented by first-principles density functional theoretical calculations using the self-interaction corrected local spin density approximation investigating in particular the magnetic structure and the Yb valence. While the ThCr2Si2-type tetragonal (I4/mmm) structure is stable up to 53 GPa, the X-ray emission results show an increase of the Yb valence from v = 2.72(2) at ambient pressure to v = 2.93(3) at ∼9 GPa, where at low temperature a pressure-induced quantum critical state was reported.

  11. In situ defect annealing of swift heavy ion irradiated CeO 2 and ThO 2 using synchrotron X-ray diffraction and a hydrothermal diamond anvil cell

    SciTech Connect

    Palomares, Raul I.; Tracy, Cameron L.; Zhang, Fuxiang; Park, Changyong; Popov, Dmitry; Trautmann, Christina; Ewing, Rodney C.; Lang, Maik

    2015-04-16

    Hydrothermal diamond anvil cells (HDACs) provide facile means for coupling synchrotron Xray techniques with pressure up to 10 GPa and temperature up to 1300 K. This manuscript reports on an application of the HDAC as an ambient-pressure sample environment for performing in situ defect annealing and thermal expansion studies of swift heavy ion irradiated CeO2 and ThO2 using synchrotron X-ray diffraction. The advantages of the in situ HDAC technique over conventional annealing methods include: rapid temperature ramping and quench times, high-resolution measurement capability, simultaneous annealing of multiple samples, and prolonged temperature- and apparatus stability at high temperatures. Isochronal annealing between 300 K and 1100 K revealed 2-stage and 1-stage defect recovery processes for irradiated CeO2 and ThO2, respectively; indicating that the morphology of the defects produced by swift heavy ion irradiation of these two materials differs significantly. These results suggest that electronic configuration plays a major role in both the radiation-induced defect production and high temperature defect recovery mechanisms of CeO2 and ThO2.

  12. In situ defect annealing of swift heavy ion irradiated CeO 2 and ThO 2 using synchrotron X-ray diffraction and a hydrothermal diamond anvil cell

    DOE PAGES

    Palomares, Raul I.; Tracy, Cameron L.; Zhang, Fuxiang; ...

    2015-04-16

    Hydrothermal diamond anvil cells (HDACs) provide facile means for coupling synchrotron Xray techniques with pressure up to 10 GPa and temperature up to 1300 K. This manuscript reports on an application of the HDAC as an ambient-pressure sample environment for performing in situ defect annealing and thermal expansion studies of swift heavy ion irradiated CeO2 and ThO2 using synchrotron X-ray diffraction. The advantages of the in situ HDAC technique over conventional annealing methods include: rapid temperature ramping and quench times, high-resolution measurement capability, simultaneous annealing of multiple samples, and prolonged temperature- and apparatus stability at high temperatures. Isochronal annealing betweenmore » 300 K and 1100 K revealed 2-stage and 1-stage defect recovery processes for irradiated CeO2 and ThO2, respectively; indicating that the morphology of the defects produced by swift heavy ion irradiation of these two materials differs significantly. These results suggest that electronic configuration plays a major role in both the radiation-induced defect production and high temperature defect recovery mechanisms of CeO2 and ThO2.« less

  13. High pressure effects on U L 3 x-ray absorption in partial fluorescence yield mode and single crystal x-ray diffraction in the heavy fermion compound UCd 11

    DOE PAGES

    Nasreen, Farzana; Antonio, Daniel; VanGennep, Derrick; ...

    2016-02-15

    © 2016 IOP Publishing Ltd. We report a study of high pressure x-ray absorption (XAS) performed in the partial fluorescence yield mode (PFY) at the U L 3 edge (0-28.2 GPa) and single crystal x-ray diffraction (SXD) (0-20 GPa) on the UCd 11 heavy fermion compound at room temperature. Under compression, the PFY-XAS results show that the white line is shifted by +4.1(3) eV at the highest applied pressure of 28.2 GPa indicating delocalization of the 5f electrons. The increase in full width at half maxima and decrease in relative amplitude of the white line with respect to the edgemore » jump point towards 6d band broadening under high pressure. A bulk modulus of K 0 = 62(1) GPa and its pressure derivative, = 4.9(2) was determined from high pressure SXD results. Both the PFY-XAS and diffraction results do not show any sign of a structural phase transition in the applied pressure range.« less

  14. High pressure effects on U L 3 x-ray absorption in partial fluorescence yield mode and single crystal x-ray diffraction in the heavy fermion compound UCd 11

    SciTech Connect

    Nasreen, Farzana; Antonio, Daniel; VanGennep, Derrick; Booth, Corwin H.; Kothapalli, Karunakar; Bauer, Eric D.; Sarrao, John L.; Lavina, Barbara; Iota-Herbei, Valentin; Sinogeikin, Stanislav; Chow, Paul; Xiao, Yuming; Zhao, Yusheng; Cornelius, Andrew L.

    2016-02-15

    © 2016 IOP Publishing Ltd. We report a study of high pressure x-ray absorption (XAS) performed in the partial fluorescence yield mode (PFY) at the U L 3 edge (0-28.2 GPa) and single crystal x-ray diffraction (SXD) (0-20 GPa) on the UCd 11 heavy fermion compound at room temperature. Under compression, the PFY-XAS results show that the white line is shifted by +4.1(3) eV at the highest applied pressure of 28.2 GPa indicating delocalization of the 5f electrons. The increase in full width at half maxima and decrease in relative amplitude of the white line with respect to the edge jump point towards 6d band broadening under high pressure. A bulk modulus of K 0 = 62(1) GPa and its pressure derivative, = 4.9(2) was determined from high pressure SXD results. Both the PFY-XAS and diffraction results do not show any sign of a structural phase transition in the applied pressure range.

  15. High pressure effects on U L3 x-ray absorption in partial fluorescence yield mode and single crystal x-ray diffraction in the heavy fermion compound UCd11

    NASA Astrophysics Data System (ADS)

    Nasreen, Farzana; Antonio, Daniel; VanGennep, Derrick; Booth, Corwin H.; Kothapalli, Karunakar; Bauer, Eric D.; Sarrao, John L.; Lavina, Barbara; Iota-Herbei, Valentin; Sinogeikin, Stanislav; Chow, Paul; Xiao, Yuming; Zhao, Yusheng; Cornelius, Andrew L.

    2016-03-01

    We report a study of high pressure x-ray absorption (XAS) performed in the partial fluorescence yield mode (PFY) at the U L3 edge (0-28.2 GPa) and single crystal x-ray diffraction (SXD) (0-20 GPa) on the UCd11 heavy fermion compound at room temperature. Under compression, the PFY-XAS results show that the white line is shifted by  +4.1(3) eV at the highest applied pressure of 28.2 GPa indicating delocalization of the 5f electrons. The increase in full width at half maxima and decrease in relative amplitude of the white line with respect to the edge jump point towards 6d band broadening under high pressure. A bulk modulus of K 0  =  62(1) GPa and its pressure derivative, K0\\prime   =  4.9(2) was determined from high pressure SXD results. Both the PFY-XAS and diffraction results do not show any sign of a structural phase transition in the applied pressure range.

  16. High pressure effects on U L3 x-ray absorption in partial fluorescence yield mode and single crystal x-ray diffraction in the heavy fermion compound UCd11.

    PubMed

    Nasreen, Farzana; Antonio, Daniel; VanGennep, Derrick; Booth, Corwin H; Kothapalli, Karunakar; Bauer, Eric D; Sarrao, John L; Lavina, Barbara; Iota-Herbei, Valentin; Sinogeikin, Stanislav; Chow, Paul; Xiao, Yuming; Zhao, Yusheng; Cornelius, Andrew L

    2016-03-16

    We report a study of high pressure x-ray absorption (XAS) performed in the partial fluorescence yield mode (PFY) at the U L3 edge (0–28.2 GPa) and single crystal x-ray diffraction (SXD) (0–20 GPa) on the UCd11 heavy fermion compound at room temperature. Under compression, the PFY-XAS results show that the white line is shifted by +4.1(3) eV at the highest applied pressure of 28.2 GPa indicating delocalization of the 5f electrons. The increase in full width at half maxima and decrease in relative amplitude of the white line with respect to the edge jump point towards 6d band broadening under high pressure. A bulk modulus of K0 = 62(1) GPa and its pressure derivative, K0 = 4.9(2) was determined from high pressure SXD results. Both the PFY-XAS and diffraction results do not show any sign of a structural phase transition in the applied pressure range.

  17. Central exclusive diffractive production of the π+π- continuum, scalar, and tensor resonances in p p and p p ¯ scattering within the tensor Pomeron approach

    NASA Astrophysics Data System (ADS)

    Lebiedowicz, Piotr; Nachtmann, Otto; Szczurek, Antoni

    2016-03-01

    We consider central exclusive diffractive dipion production in the reactions p p →p p π+π- and p p ¯ →p p ¯ π+π- at high energies. We include the dipion continuum, the dominant scalar f0(500 ), f0(980 ) , and tensor f2(1270 ) resonances decaying into the π+π- pairs. The calculation is based on a tensor Pomeron model and the amplitudes for the processes are formulated in terms of vertices respecting the standard crossing and charge-conjugation relations of quantum field theory. The formulas for the dipion continuum and tensor meson production are given here for the first time. The theoretical results are compared with existing STAR, CDF, CMS experimental data and predictions for planned or current experiments (ALICE, ATLAS) are presented. We show the influence of the experimental cuts on the integrated cross section and on various differential distributions for outgoing particles. Distributions in rapidities and transverse momenta of outgoing protons and pions as well as correlations in azimuthal angle between them are presented. We find that the relative contribution of the resonant f2(1270 ) and dipion continuum strongly depends on the cut on proton transverse momenta or four-momentum transfer squared t1 ,2 which may explain some controversial observations made by different ISR experiments in the past. The cuts may play then the role of a π π resonance filter. We suggest some experimental analyses to fix model parameters related to the Pomeron-Pomeron-f2 coupling.

  18. Heavy-Atom Labeled Transmembrane β-Peptides: Synthesis, CD-Spectroscopy, and X-ray Diffraction Studies in Model Lipid Multilayer.

    PubMed

    Rost, Ulrike; Xu, Yihui; Salditt, Tim; Diederichsen, Ulf

    2016-08-18

    Transmembrane β-peptides are promising candidates for the design of well-controlled membrane anchors in lipid membranes. Here, we present the synthesis of transmembrane β-peptides with and without tryptophan anchors, as well as a novel iodine-labeled d-β(3) -amino acid. By using one or more of the heavy-atom labeled amino acids as markers, the orientation of the helical peptide was inferred based on the electron-density profile determined by X-ray reflectivity. The β-peptides were synthesized through manual Fmoc-based solid-phase peptide synthesis (SPPS) and reconstituted in unilamellar vesicles forming a right-handed 314 -helix secondary structure, as shown by circular dichroism spectroscopy. We then integrated the β-peptide into solid-supported membrane stacks and carried out X-ray reflectivity and grazing incidence small-angle X-ray scattering to determine the β-peptide orientation and its effect on the membrane bilayers. These β-peptides adopt a well-ordered transmembrane motif in the solid-supported model membrane, maintaining the basic structure of the original bilayer with some distinct alterations. Notably, the helical tilt angle, which accommodates the positive hydrophobic mismatch, induces a tilt of the acyl chains. The tilted chains, in turn, lead to a membrane thinning effect.

  19. High-resolution diffraction for residual stress determination in the NiCrMoV wheel of an axial compressor for a heavy-duty gas turbine

    NASA Astrophysics Data System (ADS)

    Rogante, M.; Török, G.; Ceschini, G. F.; Tognarelli, L.; Füzesy, I.; Rosta, L.

    2004-07-01

    The wheel of an axial compressor for a heavy-duty gas turbine has been investigated for residual stresses (RS) evaluation of the teeth-section where SANS measurements have previously been performed. Such a component can contain internal RS, either due to the manufacturing process, or to the operating cycles fatigue. The constitutive material is a NiCrMoV steel to ASTM A 471 (type 2) norms (equivalent to B50A420B10); this material is usually adopted in the manufacturing of forged components for gas turbines. Internal radial and hoop RS have been determined, whose values are under the limit of 200kPa. Hoop RS, in general, resulted in higher value than the radial ones. The present experiment represents a particularly important step in the RS determination for gas turbine components, since the measurements reveal that the fatigue of the wheel is also a lifetime limiting factor although, in the same technological field, the available data in the actual neutron techniques literature mainly concern turbine buckets.

  20. Diffraction-Based Optical Switch

    NASA Technical Reports Server (NTRS)

    Sperno, Stevan M. (Inventor); Fuhr, Peter L. (Inventor); Schipper, John F. (Inventor)

    2005-01-01

    Method and system for controllably redirecting a light beam, having a central wavelength lambda, from a first light-receiving site to a second light-receiving site. A diffraction grating is attached to or part of a piezoelectric substrate, which is connected to one or two controllable voltage difference sources. When a substrate voltage difference is changed and the diffraction grating length in each of one or two directions is thereby changed, at least one of the diffraction angle, the diffraction order and the central wavelength is controllably changed. A diffracted light beam component, having a given wavelength, diffraction angle and diffraction order, that is initially received at a first light receiving site (e.g., a detector or optical fiber) is thereby controllably shifted or altered and can be received at a second light receiving site. A polynomially stepped, chirped grating is used in one embodiment. In another embodiment, an incident light beam, having at least one of first and second wavelengths, lambda1 and lambda2, is received and diffracted at a first diffraction grating to provide a first diffracted beam. The first diffracted beam is received and diffracted at a second diffraction grating to produce a second diffracted beam. The second diffracted beam is received at a light-sensitive transducer, having at least first and second spaced apart light detector elements that are positioned so that, when the incident light beam has wavelength lambda1 or lambda2 (lambda1 not equal to lambda2), the second diffracted beam is received at the first element or at the second element, respectively; change in a selected physical parameter at the second grating can also be sensed or measured. A sequence of spaced apart light detector elements can be positioned along a linear or curvilinear segment with equal or unequal spacing.

  1. Assessment of heavy metal contamination in intertidal gastropod and bivalve shells from central Arabian Gulf coastline, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    El-Sorogy, Abdelbaset S.; Youssef, Mohamed

    2015-11-01

    In order to assess pollutants and impact of environmental changes along the Saudi Arabian Gulf coast, forty specimens of gastropod and bivalve shells belonging to Diodora funiculata, Lunella coronata, Cerithium caeruleum, Barbatia parva, Pinctada margaritifera, Amiantis umbonella, Acrosterigma assimile and Asaphis violascens from five localities are selected for Fe, Cu, Pb, Mn, Cd, Se, As, Co, B, Cr, Hg, Mo analysis. The analysis indicated that heavy metal values (except Fe) were less than those recorded in molluscan shells from Gulf of Oman, Red Sea and Indian Ocean. D. funiculate, L. coronata, B. parva and P. margaritifera are good accumulators of Cu, As, Cr. The other species gave a nearly constant concentration in all the studied areas. Al Jubail coast recorded the highest heavy metal concentrations (except Mn at Ras Al-Ghar and Se at Al Jubail industrial city). Heavy metal contamination is mostly attributed to anthropogenic sources, especially effluents from petrochemical industries, sewage and desalination plants.

  2. Evaluation of possible health risks of heavy metals by consumption of foodstuffs available in the central market of Rajshahi City, Bangladesh.

    PubMed

    Saha, Narottam; Zaman, M R

    2013-05-01

    Considering the human health risk due to the consumption of foodstuffs, the concentrations of heavy metals (lead, manganese, chromium, cadmium, and arsenic) are investigated in vegetables, fruits, and fish species collected from the central market (called Shaheb Bazar) of Rajshahi City, Bangladesh. The foodstuffs examined for metal constituents are the basis of human nutrition in the study area. The highest concentrations of Mn and As in vegetables (onion and pointed gourd, respectively), Cr and Cd in fruits (black berry and mango, respectively), and Pb in fish (catla) are recorded. Health risks associated with these heavy metals are evaluated due to dietary intake. Target hazard quotient (THQ) and hazard index (HI) are calculated to evaluate the non-carcinogenic health risk from individual and combined heavy metals. The THQ values for individual heavy metals are below 1, suggesting that people would not experience significant health risks if they ingest a single heavy metal from one kind of foodstuff (e.g., vegetables). However, consumption of several of the foodstuffs could lead a potential health risk to human population since HI value is higher than 1. The relative contributions of vegetables, fishes, and fruits to HI are 49.44, 39.07, and 11.53 %, respectively. Also, the relative contributions of Pb, Cd, As, Mn, and Cr to HI are 51.81, 35.55, 11.73, 0.85, and 0.02 %, respectively. The estimation shows that the carcinogenic risk of arsenic exceeds the accepted risk level of 1 × 10(-6). Thus, the carcinogenic risk of arsenic for consumers is a matter of concern.

  3. Diffractive Measurements at the LHC: Elastic and Inelastic Soft Diffraction

    SciTech Connect

    Orava, Risto

    2011-07-15

    A short review of four topics was presented: (1) Photon bremsstrahlung in elastic proton-proton scattering, (2) Low mass Single Diffraction (SD), (3) Low mass Central Exclusive Diffraction (CED), and (4) Event classification of the pp interactions at the LHC. This article summarizes topic (1).

  4. Development of heavy oils and natural bitumens in the former Soviet Union and eastern and central Europe: State-of-the-art and outlook

    SciTech Connect

    Mamedov, Y.G.; Bokserman, A.A.

    1995-12-31

    The paper summarizes the results of field application of thermal oil recovery techniques (TEOR) in the former Soviet Union, and Eastern and Central Europe. All world known TEOR technologies have been tested and applied in different geological conditions in the FSU and many other East European countries. Energy saving TEOR technologies that improve the efficiency of heavy oil production have expanded the application of improved oil recovery techniques to a wider area and in different environments. TEOR technologies are very complicated, expensive, environmentally sensitive, risky, and usually uncertain. The return of capital invested is slow, and their application strongly depends on oil price and economic climate in each country, The main goal of the paper is to summarize the up-to-date R&D experience of both traditional and advanced TEOR in the Former Soviet Union, and Central and Eastern Europe.

  5. Spatial monitoring of arsenic and heavy metals in the Almyros area, Central Greece. Statistical approach for assessing the sources of contamination.

    PubMed

    Golia, E E; Dimirkou, A; Floras, St A

    2015-07-01

    The purpose of this work was to provide information on As and heavy metals content in surface soils of the Almyros area, in Central Greece. A 3-year (2009-2011) research was conducted, in order to investigate the possible temporal variation of As and heavy metal levels. Each year, a number of 251 soil samples (753 totally number of samples) were collected from the area studied, using a Differential Global Positioning System (D.G.P.S.). Soil samples were analyzed for physicochemical parameters and for pseudo-total content of metals, after digestion with Aqua Regia. Thematic maps were created, with Geographic Information Systems (GIS) techniques, using geostatistical tools. The corresponding topographical diagrams covering 15,000 ha of the study area were digitized. The thematic maps and the geostatistical analysis tools were conducted with the use of ArcGIS and the extensions Geostatistical Analyst, Spatial Analyst, and 3D analyst. Factor analysis was conducted in order to assess the possible sources of the pollution. The levels of As and metals determined were lower than the maximum permitted, except for Cd, which content was, in some cases, higher than the critical limits for soils. No statistical differences were observed among the years of the study, although a trend of continuous increasing of their content was detected. Significant correlations between heavy metal fractions and soil physicochemical parameters were obtained and discussed.

  6. Comparison between 3D-Var and 4D-Var data assimilation methods for the simulation of a heavy rainfall case in central Italy

    NASA Astrophysics Data System (ADS)

    Mazzarella, Vincenzo; Maiello, Ida; Capozzi, Vincenzo; Budillon, Giorgio; Ferretti, Rossella

    2017-08-01

    This work aims to provide a comparison between three dimensional and four dimensional variational data assimilation methods (3D-Var and 4D-Var) for a heavy rainfall case in central Italy. To evaluate the impact of the assimilation of reflectivity and radial velocity acquired from Monte Midia Doppler radar into the Weather Research Forecasting (WRF) model, the quantitative precipitation forecast (QPF) is used.The two methods are compared for a heavy rainfall event that occurred in central Italy on 14 September 2012 during the first Special Observation Period (SOP1) of the HyMeX (HYdrological cycle in Mediterranean EXperiment) campaign. This event, characterized by a deep low pressure system over the Tyrrhenian Sea, produced flash floods over the Marche and Abruzzo regions, where rainfall maxima reached more than 150 mm 24 h-1.To identify the best QPF, nine experiments are performed using 3D-Var and 4D-Var data assimilation techniques. All simulations are compared in terms of rainfall forecast and precipitation measured by the gauges through three statistical indicators: probability of detection (POD), critical success index (CSI) and false alarm ratio (FAR). The assimilation of conventional observations with 4D-Var method improves the QPF compared to 3D-Var. In addition, the use of radar measurements in 4D-Var simulations enhances the performances of statistical scores for higher rainfall thresholds.

  7. Effect of Pressure on Valence and Structural Properties of YbFe 2 Ge 2 Heavy Fermion Compound—A Combined Inelastic X-ray Spectroscopy, X-ray Diffraction, and Theoretical Investigation

    SciTech Connect

    Kumar, Ravhi S.; Svane, Axel; Vaitheeswaran, Ganapathy; Kanchana, Venkatakrishnan; Antonio, Daniel; Cornelius, Andrew L.; Bauer, Eric D.; Xiao, Yuming; Chow, Paul

    2015-10-19

    We measured the crystal structure and the Yb valence of the YbFe2Ge2 heavy fermion compound at room temperature and under high pressures using high-pressure powder X-ray diffraction and X-ray absorption spectroscopy via both partial fluorescence yield and resonant inelastic X-ray emission techniques. Moreover, the measurements are complemented by first-principles density functional theoretical calculations using the self-interaction corrected local spin density approximation investigating in particular the magnetic structure and the Yb valence. Finally, while the ThCr2Si2-type tetragonal (I4/mmm) structure is stable up to 53 GPa, the X-ray emission results show an increase of the Yb valence from v = 2.72(2) at ambient pressure to v = 2.93(3) at ~9 GPa, where at low temperature a pressure-induced quantum critical state was reported.

  8. Numerical investigations with WRF about atmospheric features leading to heavy precipitation and flood events over the Central Andes' complex topography

    NASA Astrophysics Data System (ADS)

    Zamuriano, Marcelo; Brönnimann, Stefan

    2017-04-01

    It's known that some extremes such as heavy rainfalls, flood events, heatwaves and droughts depend largely on the atmospheric circulation and local features. Bolivia is no exception and while the large scale dynamics over the Amazon has been largely investigated, the local features driven by the Andes Cordillera and the Altiplano is still poorly documented. New insights on the regional atmospheric dynamics preceding heavy precipitation and flood events over the complex topography of the Andes-Amazon interface are added through numerical investigations of several case events: flash flood episodes over La Paz city and the extreme 2014 flood in south-western Amazon basin. Large scale atmospheric water transport is dynamically downscaled in order to take into account the complex topography forcing and local features as modulators of these events. For this purpose, a series of high resolution numerical experiments with the WRF-ARW model is conducted using various global datasets and parameterizations. While several mechanisms have been suggested to explain the dynamics of these episodes, they have not been tested yet through numerical modelling experiments. The simulations captures realistically the local water transport and the terrain influence over atmospheric circulation, even though the precipitation intensity is in general unrealistic. Nevertheless, the results show that Dynamical Downscaling over the tropical Andes' complex terrain provides useful meteorological data for a variety of studies and contributes to a better understanding of physical processes involved in the configuration of these events.

  9. Kinetics of muscle deoxygenation are accelerated at the onset of heavy-intensity exercise in patients with COPD: relationship to central cardiovascular dynamics.

    PubMed

    Chiappa, Gaspar R; Borghi-Silva, Audrey; Ferreira, Leonardo F; Carrascosa, Claúdia; Oliveira, Cristino Carneiro; Maia, Joyce; Gimenes, Ana Cristina; Queiroga, Fernando; Berton, Danilo; Ferreira, Eloara M V; Nery, Luis Eduardo; Neder, J Alberto

    2008-05-01

    Patients with chronic obstructive pulmonary disease (COPD) have slowed pulmonary O(2) uptake (Vo(2)(p)) kinetics during exercise, which may stem from inadequate muscle O(2) delivery. However, it is currently unknown how COPD impacts the dynamic relationship between systemic and microvascular O(2) delivery to uptake during exercise. We tested the hypothesis that, along with slowed Vo(2)(p) kinetics, COPD patients have faster dynamics of muscle deoxygenation, but slower kinetics of cardiac output (Qt) following the onset of heavy-intensity exercise. We measured Vo(2)(p), Qt (impedance cardiography), and muscle deoxygenation (near-infrared spectroscopy) during heavy-intensity exercise performed to the limit of tolerance by 10 patients with moderate-to-severe COPD and 11 age-matched sedentary controls. Variables were analyzed by standard nonlinear regression equations. Time to exercise intolerance was significantly (P < 0.05) lower in patients and related to the kinetics of Vo(2)(p) (r = -0.70; P < 0.05). Compared with controls, COPD patients displayed slower kinetics of Vo(2)(p) (42 +/- 13 vs. 73 +/- 24 s) and Qt (67 +/- 11 vs. 96 +/- 32 s), and faster overall kinetics of muscle deoxy-Hb (19.9 +/- 2.4 vs. 16.5 +/- 3.4 s). Consequently, the time constant ratio of O(2) uptake to mean response time of deoxy-Hb concentration was significantly greater in patients, suggesting a slower kinetics of microvascular O(2) delivery. In conclusion, our data show that patients with moderate-to-severe COPD have impaired central and peripheral cardiovascular adjustments following the onset of heavy-intensity exercise. These cardiocirculatory disturbances negatively impact the dynamic matching of O(2) delivery and utilization and may contribute to the slower Vo(2)(p) kinetics compared with age-matched controls.

  10. Post-Industrial Revolution changes in large-scale atmospheric pollution of the northern hemisphere by heavy metals as documented in central Greenland snow and ice

    NASA Astrophysics Data System (ADS)

    Candelone, Jean-Pierre; Hong, Sungmin; Pellone, Christian; Boutron, Claude F.

    1995-08-01

    Pb, Zn, Cd and Cu have been measured using ultraclean procedures in various sections of a 70.3-m snow/ice core covering the past 220 years (including the Industrial Revolution) drilled at Summit, central Greenland. These time series are the first reliable ones ever published for Zn, Cd, and Cu; for Pb they are the first verification of the pioneering data published more than two decades ago by C. Patterson and his coworkers [Murozumi et al., 1969]. For all four heavy metals, concentrations are found to have markedly increased up until the 1960s and 1970s before decreasing significantly during the following few decades. The timing and the amplitude of the observed changes differ significantly however from one metal to another. Comparison with concentration values obtained by analyzing ancient Holocene ice dated 7760 years B.P., that is, before humans started to impact on the atmosphere, show that no detectable increase occurred for Zn, Cd, and Cu before the Industrial Revolution. On the other hand, Pb concentrations were already one order of magnitude above natural values in late 18th century ice. Cumulative deposition of heavy metals to the whole Greenland ice cap since the Industrial Revolution ranges from 3200 t for Pb to 60 t for Cd.

  11. Photon diffraction

    NASA Astrophysics Data System (ADS)

    Hodge, John

    2009-11-01

    In current light models, a particle-like model of light is inconsistent with diffraction observations. A model of light is proposed wherein photon inferences are combined with the cosmological scalar potential model (SPM). That the photon is a surface with zero surface area in the travel direction is inferred from the Michelson-Morley experiment. That the photons in slits are mathematically treated as a linear antenna array (LAA) is inferred from the comparison of the transmission grating interference pattern and the single slit diffraction pattern. That photons induce a LAA wave into the plenum is inferred from the fractal model. Similarly, the component of the photon (the hod) is treated as a single antenna radiating a potential wave into the plenum. That photons are guided by action on the surface of the hod is inferred from the SPM. The plenum potential waves are a real field (not complex) that forms valleys, consistent with the pilot waves of the Bohm interpretation of quantum mechanics. Therefore, the Afshar experiment result is explained, supports Bohm, and falsifies Copenhagen. The papers may be viewed at http://web.citcom.net/˜scjh/.

  12. Photoelectron diffraction

    NASA Astrophysics Data System (ADS)

    Fadley, Charles S.

    1987-01-01

    The use of core-level photoelectron diffraction for structural studies of surfaces and epitaxial overlayers is discussed. Photoelectron diffraction is found to provide several direct and rather unique types of structural information, including the sites and positions of adsorbed atoms; the orientations of small molecules or fragments bound to surfaces; the orientations, layer thicknesses, vertical lattice constants, and degrees of short-range order of epitaxial or partially-epitaxial overlayers; and the presence of short-range spin order in magnetic materials. Specific systems considered are the reaction of oxygen with Ni(001), the growth of epitaxial Cu on Ni(001), the well-defined test case S on Ni(001), and short-range spin order in the antiferromagnet KMnF3. A rather straightforward single scattering cluster (SSC) model also proves capable of quantitatively describing such data, particularly for near-surface species and with corrections for spherical-wave scattering effects and correlated vibrational motion. Promising new directions in such studies also include measurements with high angular resolution and the expanded use of synchrotron radiation.

  13. System Size, Energy, and Centrality Dependence of Pseudorapidity Distributions of Charged Particles in Relativistic Heavy-Ion Collisions

    SciTech Connect

    Alver, B.; Back, B. B.; Baker, M. D.; Barton, D. S.; Chai, Z.; Holzman, B.; Nouicer, R.; Pak, R.; Sedykh, I.; Stankiewicz, M. A.; Steinberg, P.; Sukhanov, A.; Szostak, A.; Wyngaardt, S.; Ballintijn, M.; Busza, W.; Gulbrandsen, K.; Henderson, C.; Kane, J. L.; Kulinich, P.

    2009-04-10

    We present the first measurements of the pseudorapidity distribution of primary charged particles in Cu+Cu collisions as a function of collision centrality and energy, {radical}(s{sub NN})=22.4, 62.4, and 200 GeV, over a wide range of pseudorapidity, using the PHOBOS detector. A comparison of Cu+Cu and Au+Au results shows that the total number of produced charged particles and the rough shape (height and width) of the pseudorapidity distributions are determined by the number of nucleon participants. More detailed studies reveal that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity distributions over the full range of pseudorapidity occurs for the same N{sub part}/2A rather than the same N{sub part}. In other words, it is the collision geometry rather than just the number of nucleon participants that drives the detailed shape of the pseudorapidity distribution and its centrality dependence at RHIC energies.

  14. Optimization of Mineral Separator for Recovery of Total Heavy Minerals of Bay of Bengal using Central Composite Design

    NASA Astrophysics Data System (ADS)

    Routray, Sunita; Swain, Ranjita; Rao, Raghupatruni Bhima

    2017-04-01

    The present study is aimed at investigating the optimization of a mineral separator for processing of beach sand minerals of Bay of Bengal along Ganjam-Rushikulya coast. The central composite design matrix and response surface methodology were applied in designing the experiments to evaluate the interactive effects of the three most important operating variables, such as feed quantity, wash water rate and Shake amplitude of the deck. The predicted values were found to be in good agreement with the experimental values (R2 = 0.97 for grade and 0.98 for recovery). To understand the impact of each variable, three dimensional (3D) plots were also developed for the estimated responses.

  15. The Potential Impact of Increased Phosphorus Loads in Lakes Acting as Heavy Metal Reservoirs: A case study from west-central Indiana

    NASA Astrophysics Data System (ADS)

    McLennan, D. A.; Latimer, J. C.; Smith, E.; Stone, J.

    2015-12-01

    Green Valley Lake is a designated state fishing area in west-central Indiana. Prior to this designation, the lake was a water supply reservoir for the adjacent and now abandoned Green Valley Coal Mine (Operating from 1948-1963). The Green Valley Coal Mine property continues to produce excess acidity despite reclamation efforts. The former mine property and the lake are connected by a channel that discharges acidic drainage directly into Green Valley Lake. To evaluate temporal variability in metal and phosphorus (P) geochemistry, two short cores were collected in spring 2014 (38cm) and spring 2015 (39cm). Metal concentrations were determined by a hand-held X-ray fluorescence analyzer after the samples had been dried and crushed. Approximately 20% of these metal concentrations will be verified by ICP-OES following extraction in 50% aqua regia. Detailed P geochemistry was determined using a sequential extraction technique (SEDEX). The sediments in Green Valley Lake are characterized by heavy metal concentrations that are elevated above typical background levels. These metals tend to be concentrated near the sediment water interface, often 3-5 times greater than the average concentration for the rest of the core, which suggests that they are diagenetically mobile and possibly diffusing out of the sediments under dysoxic to anoxic conditions and returning to the sediments under oxic conditions. Total sedimentary P averages 57 umol/g, but oscillates between 20 - 110 umol/g. The most dramatic shift in the detailed P geochemistry is the significant reduction of mineral P at 15 cm and the increasing importance of oxide-associated and adsorbed P upcore. Diatom assemblages suggest that the lake has become increasingly more eutrophic over time. As nutrient loads continue to increase, the oxygen depleted zone may expand impacting fish populations and changing water geochemistry significantly, in particular, mobilizing heavy metals.

  16. Pb isotopes in sediments of Lake Constance, Central Europe constrain the heavy metal pathways and the pollution history of the catchment, the lake and the regional atmosphere

    SciTech Connect

    Kober, B.; Wessels, M.; Bollhoefer, A.; Mangini

    1999-05-01

    Pb isotope ratios and Pb concentrations of well-dated sediments of Lake Constance, Central Europe have been analyzed using thermal ion mass spectrometry. Sequential extraction studies indicated isotope homogeneity of the leachable Pb components within the investigated layers. Since the middle of the 19th century a significant anthropogenic Pb component appeared in the lake sediments, and rapidly approaches concentration levels similar to that of the geogenic Pb background (20 ppm) at the beginning of the 20th century. Anthropogenic Pb was predominantly transferred to the lake sediments via the atmosphere. Pb sources were coal combustion, industrial ore processing and leaded gasoline. The flux of a fluvial Pb component to the lake sediments, additive to atmospheric Pb deposition, peaked in about 1960. This flux is attributed to (re)mobilization of Pb from polluted parts of the lake catchment, and indicates the change of catchment soils from a pollution sink to a heavy metal source. The strong reduction of anthropogenic Pb in the uppermost lake sediments since the 1960s has been caused by advances of environmental protection. The lake sediments record the changing fluxes and the isotope composition of the deposited aeolian Pb pollution. During the 20th century aeolian Pb fluxes to the lake sediments were in the range of 1--4 {micro}g/cm{sup 2}/a. During peak emission periods of gasoline Pb to the atmosphere (1960--1990) the aerosol Pb isotope composition was rather constant ({sup 206}Pb/{sup 207}Pb: 1.12--1.13) and probably a mixture of Canadian and Australian with Russian and Central European Pb types. Aeolian Pb isotope and Pb flux trends in the lake sediments as a whole agree well with the trends found in Alpine glaciers (Doering et al., 1997a,b) and in ombrotrophic peat bogs of Switzerland (Shotyk et al., 1996). However, different industrial Pb components were deposited in the archives of aeolian pollution during the early 20th century.

  17. Affects of wastewater discharge from mining on soil heavy metal pollution and enzyme activities in northern Hunan province, Central South China

    NASA Astrophysics Data System (ADS)

    Jiang, Ying; Hu, Xue-Feng; Shu, Ying; Yan, Xiao-Juan; Luo, Fan

    2013-04-01

    Hunan province, Central South China, is rich in mineral resources and also a well-known nonferrous metal base in China. Mining and ore processing there, however, are mostly conducted in indigenous methods, and thus causing heavy metal pollution of abundant farmland. Situated in northern Hunan province, Y county has antimony, manganese, vanadium, and pyrite mines, but still belongs to a region of rice cultivation, of which, paddy fields make up 84.5% of the total farmland. Our investigations found that irrigation water is threatened by the release of mining wastewater in the county. For example, a stream used for irrigation turns dark-red after long-term receiving wastewater discharged from a pyrite company at HS Town of the county. Concentrations of Cu, Zn, Cd, Fe and Mn in the stream water reach 0.03 mg kg-1, 2.14 mg kg-1, 0.02 mg kg-1, 96.0 mg kg-1 and 11.5 mg kg-1, respectively; these in the paddy soils nearby are 67.3 mg kg-1, 297 mg kg-1, 4.0 mg kg-1, 33.1 mg g-1 and 463 mg kg-1 on average, respectively, with a maximum of Cd reaching 16.8 mg kg-1. Microbial biomass and activities are significantly reduced by metal toxicity in the soils. The counts of fungal, actinomycin and bacterial colonies in the polluted soils are 8.8×103 /g (Fresh soil), 4.9×105 /g (Fresh soil) and 6.4×105 /g (Fresh soil), respectively, which are only 4.68%, 10.3% and 20.9% of these in non-polluted soils in Y county, respectively. Likewise, the microbial biomass (MB) - C and MB - N of the polluted soils are only 36.8% and 50.3% of these in the non-polluted, respectively. The activities of dehydrogenase, urease, catalase, acid and neutral phosphatase and sucrase in the polluted soils are only 41.2%, 49.8%, 56.8%, 69.9%, 80.7% and 81.0% of these in the non-polluted, respectively. There are significant negative correlations between Cu, Zn and Cd contents and the activities of dehydrogenase and catalase, suggesting that the two enzymes are the most sensitive to heavy metal toxicity in the

  18. Ecological risk assessment of heavy metals in salt-affected soils in the Natura 2000 area (Ciechocinek, north-central Poland).

    PubMed

    Bartkowiak, Agata; Lemanowicz, Joanna; Hulisz, Piotr

    2017-09-30

    This paper aimed to evaluate the ecological risk posed by the accumulation of heavy metals in the salt-affected soils of the habitat covered by the EU Natura 2000 program in relation to the activity of soil redox enzymes. The research was carried out in the halophyte reserve in Ciechocinek (north-central Poland) which is a very specific habitat as it undergoes a long-term human impact related to both the operation of the medical spa town and the agricultural use of soils in the adjacent areas. The obtained results showed that the content of Zn, Cu, Pb, and Cd in the studied soils exceeded the Polish standards. Based on the obtained data and statistical analysis, it was found that metals may come from two different sources: emission from household boiler rooms (Pb, Cd) and corroded brine sewage pipeline (Zn, Cu).They are characterized by limited mobility due to alkaline environment and strong sorption properties of the clay fraction and organic matter. The correlation analysis indicates that the dehydrogenase activities were negatively correlated with soil electrical conductivity (EC1:5) (r = - 0.665, P < 0.05). Taking into account the protective status of the area, it is difficult to indicate definitely the solution concerning the land management. However, according to the authors, one should pay special attention to a possibility of using halophytes which occur within the reserve for phytoremediation.

  19. Predictions for diffraction at the LHC compared to experimental results

    NASA Astrophysics Data System (ADS)

    Goulianos, Konstantin

    2014-04-01

    Diffractive proton-proton cross sections at the LHC, as well as the total and total-inelastic proton-proton cross sections, are predicted in a simple model obeying all unitarity constraints. The model has been implemented in the PYTHIA8-MBR event generator for single diffraction, double diffraction, and central diffraction processes. Predictions of the model are compared to recent LHC results.

  20. Fingerprinting ordered diffractions in multiply diffracted waves

    NASA Astrophysics Data System (ADS)

    Meles, Giovanni Angelo; Curtis, Andrew

    2014-09-01

    We show how to `fingerprint' individual diffractors inside an acoustic medium using interrogative wave energy from arrays of sources and receivers. For any recorded multiply diffracted wave observed between any source and any receiver, the set of such fingerprints is sufficient information to identify all diffractors involved in the corresponding diffraction path, and the sequential order in which diffractors are encountered. The method herein thus decomposes complex, multiply diffracted wavefields into constituent, single-diffraction interactions.

  1. Silt fraction heavy-mineral distributions in a lateritic environment: the rivers and insular shelf of north-central Puerto Rico

    USGS Publications Warehouse

    Poppe, L.J.; Commeau, J.A.; Luepke, G.

    1995-01-01

    This fraction, which is enriched in heavy minerals relative to the sand fraction, is mainly detrital but contains a strong authigenic component. The authigenic silt heavy-mineral fraction is largely a product of the lateritic weathering and dominated by iron oxides and alterites. Grains of bladed rutile and leached ilmenite are common. Spatial variability in silt-fraction mineralogy is considerable. Within the Rio Cibuco system variability is related to compositional differences in rapidly eroding source rocks. On the shelf, silt heavy-mineral abundances are greatest at the river mouths and decrease seaward. Variability in the shelf samples is controlled primarily by source rivers and shelf sorting processes. -from Authors

  2. Synoptic climatological study on the decrease in heavy snowfall days in Hokuriku District of Central Japan after the latter half of 1980s

    NASA Astrophysics Data System (ADS)

    Kato, Kuranoshin; Kan, Yuusuke

    2010-05-01

    Many reports point out that the total snowfall amount in winter in the Japan Sea side of the Japan Islands, such as Hokuriku District, decreased considerably after the latter half of 1980s, in coincidence with the Global Warming together with the interdecadal variation. As for around December, this seems to be partly because more precipitation in the winter monsoon situation is brought as rainfall (not as snowfall), due to the warmer temperature than before. On the other hand, contribution of the daily heavy snowfall events there would be also important for mid-winter when the air temperature is the lowest in a year. Thus the present study examined the contribution of the heavy snowfall events to the difference of the total snowfall amount before and after the middle of 1980s, based on the daily data at several operational surface observation stations of JMA in the Hokuriku District for 1971 - 2001. Then the related daily atmospheric fields were analyzed climatologically with use of the NCEP/NCAR re-analysis data with every 2.5 degrees latitude/longitude interval. In the former half of the analysis period, the larger total snowfall amount in January in the Hokuriku District, such as at Takada, was greatly contributed to by the heavy snowfall events with more than 30 cm/day (referred to as "heavy snowfall day", hereafter). The decrease in the total amount in the latter half of that period was due to that in the contribution of "heavy snowfall days". Furthermore, the "heavy snowfall days" tended to appear in the persistent snowfall episodes (including also the days with 10 cm/day), before around 1986. In short, the decrease in the total snowfall in the latter half period there seems to be reflected by the weakening of persistency of heavy snowfall episodes. As shown by Akiyama (1981a and b) in detail, there are several different synoptic situations in the winter monsoon situation for bringing heavy snowfall there (the "mountain snow type" and the "plateau snow type

  3. X-Ray Diffraction.

    ERIC Educational Resources Information Center

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  4. Dynamic versus Static Structure Functions and Novel Diffractive Effects in QCD

    SciTech Connect

    Brodsky, Stanley J.

    2008-11-12

    Initial- and final-state rescattering, neglected in the parton model, have a profound effect in QCD hard-scattering reactions, predicting single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency, and anomalous heavy quark effects. The presence of direct higher-twist processes where a proton is produced in the hard subprocess can explain the large proton-to-pion ratio seen in high centrality heavy ion collisions. I emphasize the importance of distinguishing between static observables such as the probability distributions computed from the square of the light-front wavefunctions versus dynamical observables which include the effects of rescattering.

  5. Diffractive corneal inlay for presbyopia.

    PubMed

    Furlan, Walter D; García-Delpech, Salvador; Udaondo, Patricia; Remón, Laura; Ferrando, Vicente; Monsoriu, Juan A

    2017-09-01

    A conceptually new type of corneal inlays for a customized treatment of presbyopia is presented. The diffractive inlay consists on a small aperture disc having an array of micro-holes distributed inside the open zones of a Fresnel zone plate. In this way, the central hole of the disc lets pass the zero order diffraction and produces an extension of the depth of far focus of the eye, while the diffracted light through the holes in the periphery produce the near focus. Additionally, the micro-holes in the inlay surface fulfill the essential requirement of allowing the flow of nutrients through it to the cells of the corneal stroma. Theoretical and optical-bench experimental results for the polychromatic axial Point Spread Function (PSF) were obtained, showing an improved performance compared to the small aperture corneal inlay currently in the market (Kamra). Images of a test object, obtained at several vergences in the surroundings of the far and near foci, are also shown. Picture: Simulation of the appearance of the Diffractive corneal inlay on a real eye. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Algorithmic methods in diffraction microscopy

    NASA Astrophysics Data System (ADS)

    Thibault, Pierre

    Recent diffraction imaging techniques use properties of coherent sources (most notably x-rays and electrons) to transfer a portion of the imaging task to computer algorithms. "Diffraction microscopy" is a method which consists in reconstructing the image of a specimen from its diffraction pattern. Because only the amplitude of a wavefield incident on a detector is measured, reconstruction of the image entails to recovering the lost phases. This extension of the 'phase problem" commonly met in crystallography is solved only if additional information is available. The main topic of this thesis is the development of algorithmic techniques in diffraction microscopy. In addition to introducing new methods, it is meant to be a review of the algorithmic aspects of the field of diffractive imaging. An overview of the scattering approximations used in the interpretation of diffraction datasets is first given, as well as a numerical propagation tool useful in conditions where known approximations fail. Concepts central to diffraction microscopy---such as oversampling---are then introduced and other similar imaging techniques described. A complete description of iterative reconstruction algorithms follows, with a special emphasis on the difference map, the algorithm used in this thesis. The formalism, based on constraint sets and projection onto these sets, is then defined and explained. Simple projections commonly used in diffraction imaging are then described. The various ways experimental realities can affect reconstruction methods will then be enumerated. Among the diverse sources of algorithmic difficulties, one finds that noise, missing data and partial coherence are typically the most important. Other related difficulties discussed are the detrimental effects of crystalline domains in a specimen, and the convergence problems occurring when the support of a complex-valued specimen is not well known. The last part of this thesis presents reconstruction results; an

  7. Experimental results on diffraction at CDF

    SciTech Connect

    Gallinaro, Michele; /Rockefeller U. /Lisbon, LIFEP

    2010-09-01

    Diffractive events are studied by means of identification of one or more rapidity gaps and/or a leading antiproton. Measurements of soft and hard diffractive processes have been performed at the Tevatron p{bar p} collider and presented. We report on the diffractive structure function obtained from dijet production in the range 0 < Q{sup 2} < 10,000 GeV{sup 2}, and on the |t| distribution in the region 0 < |t| < 1 GeV{sup 2} for both soft and hard diffractive events up to Q{sup 2} {approx} 4,500 GeV{sup 2}. Results on single diffractive W/Z production, forward jets, and central exclusive production of both dijets and Z-bosons are also presented.

  8. Analysis of heavy metal content of Pb in ballast water tank of commercial vessels in port of Tanjung Emas Semarang, Central Java province

    NASA Astrophysics Data System (ADS)

    Tjahjono, Agus; Bambang, Azis Nur; Anggoro, Sutrisno

    2017-03-01

    Commercial vessels that do not conduct ballast water exchange, in accordance with International Convention Ballast Water Management, will endager the environment of ports. This research is aimed to know the metal content in ballast water tank of commercial vessels that have not performed ballast water exchange, in accordance with regulations of International Maritime Organization (IMO). The research about the heavy metal content of ballast water of commercial vessels, both passenger or cargo vessels, berthing in Port of Tanjung Emas Semarang (PTES), has been conducted by using method of AAS (Atomic Absorption Spectroscopy). Sample was gathered from vessels berthed in PTES, dated on December 18th 2014 to October 21st 2015. Results of the research show that the mean content of Pb in ballast water tank is 0.37192 mg/l. Based on the Decree of Minister of Environment Number 51/2004, the heavy metal content of Pb in ballast water tank has exceeded the quality standards of port waters.

  9. Multiple provenance of rift sediments in the composite basin-mountain system: Constraints from detrital zircon U-Pb geochronology and heavy minerals of the early Eocene Jianghan Basin, central China

    NASA Astrophysics Data System (ADS)

    Wu, Lulu; Mei, Lianfu; Liu, Yunsheng; Luo, Jin; Min, Caizheng; Lu, Shengli; Li, Minghua; Guo, Libin

    2017-03-01

    Zircon U-Pb geochronology and heavy minerals are used in combination to provide valuable insights into the provenance of the early Eocene Jianghan Basin, central China. Five samples for zircon U-Pb dating and eighty-five samples for heavy mineral analysis were collected from drill cores or cuttings of the Xingouzui Formation. Most analyzed zircons are of magmatic origin, with oscillatory zoning. Detrital zircons from sample M96 located on eastern basin have two dominant age groups of 113-158 Ma and 400-500 Ma, and the other samples located on southern basin have three prominent age populations at 113-158 Ma, 400-500 Ma and 700-1000 Ma. Samples on different parts of the basin show distinct differences in heavy mineral compositions and they apparently divide into two groups according to the content of rutile (higher or lower than 4%). The spatial variations of zircon-tourmaline-rutile (ZTR) indices are marked by some noticeable increasing trends from basin margins to the inner part of the basin. Compared with the potential source areas, this study clarifies the multiple source characteristics of the Jianghan basin in the composite basin-mountain system. The majority of clastic material was supplied from the north source area through rift-trough sediment-transport pathways, and the eastern, southern and northwestern source areas also contributed detritus to the basin. This clastic material is broadly dispersed in the basin. The early Eocene paleogeography implies that rift architecture and rifting process had an important influence on sediment dispersal. This study shows that integrated zircon U-Pb geochronology and heavy mineral analysis is a useful and powerful method to identify sediment provenance.

  10. Concentrations of selected heavy metals in bryophyte tissues at Cu-mine heap Podlipa in Ľubietová (Central Slovakia)

    NASA Astrophysics Data System (ADS)

    Širka, Pavel; Midula, Pavol

    2017-04-01

    Mine heaps and wastes created by mining industry belong to one of the most extreme man-made habitat types. In addition to their specific microclimatic conditions mine heaps are also characterized by increased contents of heavy metals and toxic substances in the soil substrate. These substances are transported into plant bodies and create difficult conditions for their growth. However, there are some plants that can cope with extremely high metal contents and are capable of growing on metalliferous habitats. These plants develop unique adaptation mechanisms and basically represent modified ecotypes with specific tolerances to certain heavy metals adapted through microevolutionary processes. The toxic effects of heavy metals on vascular plants are known for quite a long time, however, bryophytes are also known to accumulate certain heavy metals without any visible signs of damage. Because of this ability they have been successfully used in biomonitoring. Chemical analysis of contaminants in samples of bryophytes can reflect the state of environmental pollution. The aim of this work was to analyze the concentrations of 6 heavy metals (Fe, Cu, Zn, Mn, Pb and Cd) in tissues of 16 bryophyte samples at an abandoned Cu deposit Podlipa in Ľubietová and to compare them with concentrations of these elemens in soil samples and 9 vascular plant species (belonging to different growth forms) in a research performed by Andráš et al. (2014) in the studied area. Bryophytes were collected at 10 sampling sites randomly chosen in the dump-field area and consist of 14 different moss species. Only above-ground parts of bryophyte thalli (separated from rhizoids, gravel, soil, needles etc.) were used for analysis. Samples were dried at room temperature and subjected to microwave mineralization (MWS - 2 Berghof). The detailed procedure is defined in the Application Report MWS - 2 / Food, Pharma, Cosmetics (Berghof). In order to determine the concentrations of studied elements, atomic

  11. Fiber diffraction without fibers.

    PubMed

    Poon, H-C; Schwander, P; Uddin, M; Saldin, D K

    2013-06-28

    Postprocessing of diffraction patterns of completely randomly oriented helical particles, as measured, for example, in so-called "diffract-and-destroy" experiments with an x-ray free electron laser can yield "fiber diffraction" patterns expected of fibrous bundles of the particles. This will allow "single-axis alignment" to be performed computationally, thus obviating the need to do this by experimental means such as forming fibers and laser or flow alignment. The structure of such particles may then be found by either iterative phasing methods or standard methods of fiber diffraction.

  12. Robustness of Cantor diffractals.

    PubMed

    Verma, Rupesh; Sharma, Manoj Kumar; Banerjee, Varsha; Senthilkumaran, Paramasivam

    2013-04-08

    Diffractals are electromagnetic waves diffracted by a fractal aperture. In an earlier paper, we reported an important property of Cantor diffractals, that of redundancy [R. Verma et. al., Opt. Express 20, 8250 (2012)]. In this paper, we report another important property, that of robustness. The question we address is: How much disorder in the Cantor grating can be accommodated by diffractals to continue to yield faithfully its fractal dimension and generator? This answer is of consequence in a number of physical problems involving fractal architecture.

  13. Centrality dependence of the parton bubble model for high-energy heavy-ion collisions and fireball surface substructure at energies available at the BNL relativistic heavy ion collider (RHIC)

    SciTech Connect

    Lindenbaum, S. J.; Longacre, R. S.

    2008-11-15

    In an earlier paper we developed a QCD-inspired theoretical parton bubble model (PBM) for RHIC/LHC. The motivation for the PBM was to develop a model that would reasonably quantitatively agree with the strong charged particle pair correlations observed by the STAR Collaboration at RHIC in Au+Au central collisions at {radical}(s{sub NN})=200 GeV in the transverse momentum range 0.8 to 2.0 GeV/c. The model was constructed to also agree with the Hanbury Brown and Twiss (HBT) observed small final-state source size {approx}2 fm radii in the transverse momentum range above 0.8 GeV/c. The model assumed a substructure of a ring of localized adjoining {approx}2 fm radius bubbles perpendicular to the collider beam direction, centered on the beam, at midrapidity. The bubble ring was assumed to be located on the expanding fireball surface of the Au+Au collision. These bubbles consist almost entirely of gluons and form gluonic hot spots on the fireball surface. We achieved a reasonable quantitative agreement with the results of both the physically significant charge-independent (CI) and charge-dependent (CD) correlations that were observed. In this paper we extend the model to include the changing development of bubbles with centrality from the most central region where bubbles are very important to the most peripheral where the bubbles are gone. Energy density is found to be related to bubble formation and as centrality decreases the maximum energy density and bubbles shift from symmetry around the beam axis to the reaction plane region, causing a strong correlation of bubble formation with elliptic flow. We find reasonably quantitative agreement (within a few percent of the total correlations) with a new precision RHIC experiment that extended the centrality region investigated to the range 0%-80% (most central to most peripheral). The characteristics and behavior of the bubbles imply they represent a significant substructure formed on the surface of the fireball at kinetic

  14. Local to regional scale industrial heavy metal pollution recorded in sediments of large freshwater lakes in central Europe (lakes Geneva and Lucerne) over the last centuries.

    PubMed

    Thevenon, Florian; Graham, Neil D; Chiaradia, Massimo; Arpagaus, Philippe; Wildi, Walter; Poté, John

    2011-12-15

    This research first focuses on the spatial and temporal patterns of heavy metals from contrasting environments (highly polluted to deepwater sites) of Lake Geneva. The mercury (Hg) and lead (Pb) records from two deepwater sites show that the heavy metal variations before the industrial period are primarily linked to natural weathering input of trace elements. By opposition, the discharge of industrial treated wastewaters into Vidy Bay of Lake Geneva during the second part of the 20th century, involved the sedimentation of highly metal-contaminated sediments in the area surrounding the WWTP outlet pipe discharge. Eventually, a new Pb isotope record of sediments from Lake Lucerne identifies the long-term increasing anthropogenic lead pollution after ca. 1500, probably due to the development of metallurgical activities during the High Middle Ages. These data furthermore allows to compare the recent anthropogenic sources of water pollution from three of the largest freshwater lakes of Western Europe (lakes Geneva, Lucerne, and Constance). High increases in Pb and Hg highlight the regional impact of industrial pollution after ca. 1750-1850, and the decrease of metal pollution in the 1980s due to the effects of remediation strategies such as the implementation of wastewater treatment plants (WWTPs). However, at all the studied sites, the recent metal concentrations remain higher than pre-industrial levels. Moreover, the local scale pollution data reveal two highly contaminated sites (>100 μg Pb/g dry weight sediment) by industrial activities, during the late-19th and early-20th centuries (Lake Lucerne) and during the second part of the 20th century (Vidy Bay of Lake Geneva). Overall, the regional scale pollution history inferred from the three large and deep perialpine lakes points out at the pollution of water systems by heavy metals during the last two centuries due to the discharge of industrial effluents. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Phononic crystal diffraction gratings

    NASA Astrophysics Data System (ADS)

    Moiseyenko, Rayisa P.; Herbison, Sarah; Declercq, Nico F.; Laude, Vincent

    2012-02-01

    When a phononic crystal is interrogated by an external source of acoustic waves, there is necessarily a phenomenon of diffraction occurring on the external enclosing surfaces. Indeed, these external surfaces are periodic and the resulting acoustic diffraction grating has a periodicity that depends on the orientation of the phononic crystal. This work presents a combined experimental and theoretical study on the diffraction of bulk ultrasonic waves on the external surfaces of a 2D phononic crystal that consists of a triangular lattice of steel rods in a water matrix. The results of transmission experiments are compared with theoretical band structures obtained with the finite-element method. Angular spectrograms (showing frequency as a function of angle) determined from diffraction experiments are then compared with finite-element simulations of diffraction occurring on the surfaces of the crystal. The experimental results show that the diffraction that occurs on its external surfaces is highly frequency-dependent and has a definite relation with the Bloch modes of the phononic crystal. In particular, a strong influence of the presence of bandgaps and deaf bands on the diffraction efficiency is found. This observation opens perspectives for the design of efficient phononic crystal diffraction gratings.

  16. Diffraction Results from CDF

    SciTech Connect

    Goulianos, Konstantin

    2012-04-01

    We present final results by the CDF II collaboration on diffractive W and Z production, report on the status of ongoing analyses on diffractive dijet production and on rapidity gaps between jets, and briefly summarize results obtained on exclusive production pointing to their relevance to calibrating theoretical models used to predict exclusive Higgs-boson production at the LHC.

  17. Analysis of heavy metal content of Cd and Zn in ballast water tank of commercial vessels in Port of Tanjung Emas Semarang, Central Java Province

    NASA Astrophysics Data System (ADS)

    Tjahjono, A.; Bambang, A. N.; Anggoro, S.

    2017-02-01

    Commercial vessels that do not conduct ballast water exchange, in accordance with International Convention Ballast Water Management, will endager the environment of ports. This research is aimed to know the metal content in ballast water tank of commercial vessels that have not performed ballast water exchange, in accordance with regulations of International Maritime Organization (IMO). The present research is focused on the heavy metal content of ballast water of commercial vessels, both passenger or cargo vessells, berthing in Port of Tanjung Emas Semarang (PTES). Water sample in ballast tank is collected by method of AAS (Atomic Absorption Spectrophotometer). Results of the research show that the content of Cd is about 0.001-0.46 mg l-1, and Zn is about 0.001-2.464 mg l-1. Based on the Decree of Minister of Environment Number 51/2004, the heavy metal content of Cd and Zn has exceeded quality standards of sea water for port water, which is 0.1 mg l-1 both.

  18. Central μ-Opioidergic System Activation Evoked by Heavy and Severe-Intensity Cycling Exercise in Humans: a Pilot Study Using Positron Emission Tomography with 11C-Carfentanil.

    PubMed

    Hiura, Mikio; Sakata, Muneyuki; Ishii, Kenji; Toyohara, Jun; Oda, Keiichi; Nariai, Tadashi; Ishiwata, Kiichi

    2017-01-01

    The central opioid receptor system likely contributes to the mechanism underlying the changes in affect elicited by exercise. Our aim was to use positron emission tomography (PET) to test whether exercise intensity influences activation of the μ-opioid receptor system in the brain, and whether changes in opioid receptor activation correlate with exercise-induced changes in affect. 7 healthy young male subjects (23±2 years) performed 20-min constant-load cycling exercises at heavy (ExH) and severe-intensity (ExS), and PET was performed using [(11)C]carfentanil as a tracer before and after each exercise. Exercise elicited the μ-opioidergic system activation in the large areas of the limbic system, particularly in the insular cortex, and cerebellum. Of note, deactivation of the μ-opioidergic system in the pituitary gland was identified as a specific finding in ExS, which evoked a distinctive sensation of fatigue. Within these brain areas, μ-opioid receptor activation correlated positively with increased positive affect (R(2)=0.67-0.95) in ExH and negative affect (R(2)=0.63-0.77) in ExS. These findings suggest that central μ-opioidergic neurotransmission evoked by continuous exercise is discriminated by work intensity. Notably, we also observed a possible contribution of the central μ-opioidergic system to the development of the sensation of fatigue during exhaustive exercise. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Multilayer dielectric diffraction gratings

    DOEpatents

    Perry, Michael D.; Britten, Jerald A.; Nguyen, Hoang T.; Boyd, Robert; Shore, Bruce W.

    1999-01-01

    The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described.

  20. Multilayer dielectric diffraction gratings

    DOEpatents

    Perry, M.D.; Britten, J.A.; Nguyen, H.T.; Boyd, R.; Shore, B.W.

    1999-05-25

    The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described. 7 figs.

  1. Diffraction at Hera

    NASA Astrophysics Data System (ADS)

    Collard, C.

    2003-02-01

    At the electron-proton collider HERA, diffractive interactions represent ~ 10% of the deep inelastic scattering. The production of diffractive events, characterised by the presence of a gap in rapidity or angular region without particle production, can be explained in the framework of the Regge model by the exchange of a colorless object, named the Pomeron. Describing the nature of the pomeron is a challenge for Quantum Chromodynamics. Results from the H1 and ZEUS Collaborations on exclusive vector meson production and on inclusive diffractive processes are presented.

  2. Fresnel Coherent Diffractive Imaging

    SciTech Connect

    Williams, G. J.; Quiney, H. M.; Dhal, B. B.; Tran, C. Q.; Nugent, K. A.; Peele, A. G.; Paterson, D.; Jonge, M. D. de

    2006-07-14

    We present an x-ray coherent diffractive imaging experiment utilizing a nonplanar incident wave and demonstrate success by reconstructing a nonperiodic gold sample at 24 nm resolution. Favorable effects of the curved beam illumination are identified.

  3. Fraunhofer Diffraction and Polarization.

    ERIC Educational Resources Information Center

    Fortin, E.

    1979-01-01

    Describes an experiment for the intermediate undergraduate optics laboratory designed to illustrate simultaneously some aspects of the phenomena of diffraction; interference, coherence, apodization, the Fresnel-Arago law; as well as of the interrelations between these concepts. (HM)

  4. Diffraction with CMS

    SciTech Connect

    Pereira, Antonio Vilela

    2011-07-15

    The observation of diffraction at LHC with the CMS detector at {radical}(s) = 900 and 2360 GeV is presented, along with a comparison of the data with the predictions of the PYTHIA and PHOJET generators.

  5. Diffraction as tunneling

    NASA Technical Reports Server (NTRS)

    Nussenzveig, H. M.; Wiscombe, W. J.

    1987-01-01

    A new approximation to the short-wavelength scattering amplitude from an impenetrable sphere is presented. It is uniform in the scattering angle and it is more accurate than previously known approximations (including Fock's theory of diffraction) by up to several orders of magnitude. It remains valid in the transition to long-wavelength scattering. It leads to a new physical picture of diffraction, as tunneling through an inertial barrier.

  6. Reflective diffraction grating

    DOEpatents

    Lamartine, Bruce C.

    2003-06-24

    Reflective diffraction grating. A focused ion beam (FIB) micromilling apparatus is used to store color images in a durable medium by milling away portions of the surface of the medium to produce a reflective diffraction grating with blazed pits. The images are retrieved by exposing the surface of the grating to polychromatic light from a particular incident bearing and observing the light reflected by the surface from specified reception bearing.

  7. Anomalous diffraction approximation limits

    NASA Astrophysics Data System (ADS)

    Videen, Gorden; Chýlek, Petr

    It has been reported in a recent article [Liu, C., Jonas, P.R., Saunders, C.P.R., 1996. Accuracy of the anomalous diffraction approximation to light scattering by column-like ice crystals. Atmos. Res., 41, pp. 63-69] that the anomalous diffraction approximation (ADA) accuracy does not depend on particle refractive index, but instead is dependent on the particle size parameter. Since this is at odds with previous research, we thought these results warranted further discussion.

  8. Heavy Flavors

    NASA Astrophysics Data System (ADS)

    Cox, B.; Soni, A.

    This is a summary report of the working group on Heavy Flavors. Discussions at the workshop were centered on B physics and on the signals for heavy quarks and leptons at the SSC. The Working Group Members were: V. Barger, H.-U. Bengtsson, C. Buchanan, I. Bigi, M. Block, B. Cox, N. Glover, J. Hewett, W.Y. Keung, B. Margolis, T. Rizzo, M. Suzuki, A. Soni, D. Stork, and S. Willenbrock.

  9. Centrality dependence of the direct photon yield and elliptic flow in heavy-ion collisions at √sNN =200 GeV

    NASA Astrophysics Data System (ADS)

    Linnyk, O.; Cassing, W.; Bratkovskaya, E. L.

    2014-03-01

    We calculate the centrality dependence of direct photons produced in Au+Au collisions at the invariant collision energy √sNN =200 GeV and their transverse momentum spectra within the parton-hadron-string dynamics transport approach. As sources for "direct" photons, we incorporate the interactions of quarks and gluons as well as hadronic interactions (π +π→ρ+γ, ρ +π→π+γ, meson-meson bremsstrahlung m +m→m+m+γ, and meson-baryon bremsstrahlung m +B→m+B+γ), the decays of ϕ and a1 mesons, and the photons produced in the initial hard collisions. We find that the transverse momentum pT spectra of the "thermal" photons (i.e., the direct photons after the pQCD contribution is subtracted) deviate from exponential distributions and, consequently, observe a strong dependence of the inverse slope parameter Teff on the fitting range in pT. On the other hand, all the obtained "effective temperatures" are well above the critical temperature for the deconfinement phase transition even for peripheral collisions, reflecting primarily a "blue shift" due to radial collective motion of hadrons. Our calculations suggest that the channel decomposition of the observed spectrum changes with centrality with an increasing (dominant) contribution of hadronic sources for more peripheral reactions. Furthermore, the thermal photon yield is found to scale roughly with the number of participant nucleons as Npartα with α ≈ 1.5, whereas the partonic contribution scales with an exponent αp≈1.75. Additionally, we provide predictions for the centrality dependence of the direct photon elliptic flow v2(pT). The photons from the hot deconfined matter in the early stages of the collision carry a much smaller elliptic flow than the final hadrons. Consequently, the direct photon v2 in the most central bin is of the order of a few percent. On the other hand, the elliptic flow of direct photons is considerably larger in more peripheral collisions, approaching that of hadrons.

  10. Diffraction light analysis method for a diffraction grating imaging lens.

    PubMed

    Ando, Takamasa; Korenaga, Tsuguhiro; Suzuki, Masa-aki; Tanida, Jun

    2014-04-10

    We have developed a new method to analyze the amount and distribution of diffraction light for a diffraction grating lens. We have found that diffraction light includes each-order diffraction light and striped diffraction light. In this paper, we describe characteristics of striped diffraction light and suggest a way to analyze diffraction light. Our analysis method, which considers the structure of diffraction grating steps, can simulate the aberrations of an optical system, each-order diffraction light, and striped diffraction light simultaneously with high accuracy. A comparison between the simulation and experimental results is presented, and we also show how our analysis method can be used to optimize a diffraction grating lens with low flare light.

  11. Multipath analysis diffraction calculations

    NASA Technical Reports Server (NTRS)

    Statham, Richard B.

    1996-01-01

    This report describes extensions of the Kirchhoff diffraction equation to higher edge terms and discusses their suitability to model diffraction multipath effects of a small satellite structure. When receiving signals, at a satellite, from the Global Positioning System (GPS), reflected signals from the satellite structure result in multipath errors in the determination of the satellite position. Multipath error can be caused by diffraction of the reflected signals and a method of calculating this diffraction is required when using a facet model of the satellite. Several aspects of the Kirchhoff equation are discussed and numerical examples, in the near and far fields, are shown. The vector form of the extended Kirchhoff equation, by adding the Larmor-Tedone and Kottler edge terms, is given as a mathematical model in an appendix. The Kirchhoff equation was investigated as being easily implemented and of good accuracy in the basic form, especially in phase determination. The basic Kirchhoff can be extended for higher accuracy if desired. A brief discussion of the method of moments and the geometric theory of diffraction is included, but seems to offer no clear advantage in implementation over the Kirchhoff for facet models.

  12. Newton's diffraction measurements

    NASA Astrophysics Data System (ADS)

    Nauenberg, Michael

    2004-05-01

    This year marks the tercentenary of the publication of Newton's Opticks which contains his celebrated theory and experiments of light and colors as it evolved from the first published version in 1672. It is still fairly unknown, however, that in this book Newton also reported his experiments on diffraction fringes obtained from various "slender" objects placed in a beam of sunlight. These experiments posed an insurmountable difficulty to Newton's corpuscular theory of light, which failed to account for his observations. This failure explains the long delay in the publication of this book. In my talk I will compare Newton's experimental results on diffraction with the predictions of Fresnel's wave theory to demonstrate that his measurements were remarkable accurate. Eventually these measurements paved the way for Young's correct explanation of the diffraction fringes as a wave interference phenomenon.

  13. Promotion of renewable energy to mitigate impact of heavy use of carbon energy on society and climate change in Central Sub-Saharan Africa remote areas.

    NASA Astrophysics Data System (ADS)

    Kenfack, Joseph; Bignom, Blaise

    2015-04-01

    Sub-Saharan Africa owns important renewable energy potential and is still heavily using carbon energy. This is having a negative impact on the climate and on the environment. Given the local cost of carbon energy, the purchase power of people, the availability and the reserve of carbon energy in the area, this resource is being heavily used. This practice is harmful to the climate and is also resulting on poor effort to promote renewable energy in remote areas. The important renewable energy potential is still suffering from poor development. The purpose of this paper is among other things aiming at showing the rate of carbon energy use and its potential impact on climate and environment. We will also ensure that the renewable energy resources of Central Sub-Saharan Africa are known and are subject to be used optimally to help mitigate climate change. After showing some negative impacts of carbon energy used in the area, the work also suggests actions to promote and sustain the development of renewable energy. Based on the knowledge of the Central African energy sector, this paper will identify actions for reduce access to carbon energy and improved access to sustainable, friendly, affordable energy services to users as well as a significant improvement of energy infrastructure and the promotion of energy efficiency. We will show all type of carbon energy used, the potential for solar, biomass and hydro while showing where available the level of development. After a swot analysis of the situation, identified obstacles for the promotion of clean energy will be targeted. Finally, suggestions will be made to help the region develop a vision aiming at developing good clean energy policy to increase the status of renewable energy and better contribute to fight against climate change. Cameroon case study will be examined as illustration. Analysis will be made from data collected in the field. |End Text|

  14. Single molecule diffraction.

    PubMed

    Spence, J C H; Doak, R B

    2004-05-14

    For solving the atomic structure of organic molecules such as small proteins which are difficult to crystallize, the use of a jet of doped liquid helium droplets traversing a continuous high energy electron beam is proposed as a means of obtaining electron diffraction patterns (serial crystallography). Organic molecules (such as small proteins) within the droplet (and within a vitreous ice jacket) may be aligned by use of a polarized laser beam. Iterative methods for solving the phase problem are indicated. Comparisons with a related plan for pulsed x-ray diffraction from single proteins in a molecular beam are provided.

  15. Biopolymer holographic diffraction gratings

    NASA Astrophysics Data System (ADS)

    Savić Šević, Svetlana; Pantelić, Dejan

    2008-03-01

    Surface-relief diffraction gratings are holographically recorded in dextran sensitized with ammonium dichromate (DCD). DCD was exposed with single-frequency 200 mW diode pumped ND-YAG laser, at 532 nm. The diffraction grating profiles were analyzed by atomic force microscopy (AFM). It was found that different surface profiles could be obtained. Gratings with 330 lines/mm spatial frequencies were made. Existence of higher harmonics in Fourier Transform of non-sinusoidal profiles shows that DCD is capable of recording spatial frequencies up to 1320 lines/mm (four times fundamental frequency). The measured maximum relief depth of the DCD grating is 402 nm.

  16. Measurements of diffractive and exclusive processes with ATLAS

    NASA Astrophysics Data System (ADS)

    Dyndal, Mateusz

    2017-03-01

    The ATLAS collaboration has carried out a range of measurements related with diffractive and exclusive processes. In the absence of forward proton tagging, these processes can be distinguished in the central part of the ATLAS detector exploiting the large rapidity gap in the central region and the absence of charged particles reconstructed in the inner tracking detector. This strategy has been applied to study the exclusive production of lepton pairs and the diffractive dijet production.

  17. Transverse-energy production and fluctuations over centrality and acceptance in relativistic heavy-ion and nucleon-nucleon collisions: Quark versus nucleon interactions and a search for the quark-gluon plasma

    NASA Astrophysics Data System (ADS)

    Armendariz, Raul L.

    Measuring energy produced in relativistic heavy-ion collisions is a way to investigate if a model of quark participants, or nucleon participants better describes the internal dynamics of the collision. The energy produced is proportional to the energy density in the interaction region; changes in fluctuations of energy production could be a signature for a phase transition between ordinary hadronic matter to a liberated quark-gluon plasma phase, QGP, thought to have existed one millionth of a second after the Big Bang creation of the Universe and before protons and neutrons had formed. Three experimental nuclear physics data-analyses were conducted using the sum energy of all particles produced in the direction transverse to the beam, ET, when nuclei collide in a 2.4 mile long circular atom smasher. The nuclei are accelerated in opposite directions at 99.995% the speed of light, and center-of-mass energies available for new particle production of sNN = 62.4 GeV, and 200 GeV per colliding nucleon pair were studied. The ET was recorded by the lead-scintillator electromagnetic calorimeter detectors of the Pioneering High Energy Interactions Experiment (PHENIX), at the Relativistic heavy Ion Collider (RHIC), of Brookhaven National Laboratory (BNL). The collision systems studied were 200 GeV protons with protons ( p + p), deuterons with Au ions (d+Au), and 62.4 GeV and 200 GeV gold ions with gold ions (Au+Au). The first analysis, mean ET in collision centrality, explores whether a model of nucleon participants, or quark participants, better describes energy production with collision impact. The second analysis, ET fluctuations in collision centrality, looks for non-random fluctuations in ET distributions when the density of colliding partons becomes high. The third analysis, ET fluctuations in geometric acceptance, examines fluctuations as a function of detector fiducial volume in a search for correlated energy distribution in space (correlations ), known to occur in

  18. Evaluation of some factors influencing on variability in bioaccumulation of heavy metals in rodents species: Rombomys opimus and Rattus norvegicus from central Iran.

    PubMed

    Zarrintab, Mohammad; Mirzaei, Rouhollah

    2017-02-01

    In the present study, the effects of sex, age, nutritional status, and habitat use on hair and internal tissue concentrations of some trace metals (Zn, Cu, Ni, Pb and Cd) in brown rat (Rattus norvegicus) and great gerbil (Rhombomys opimus) from Aran-O-Bidgol City in Central Iran were investigated. Five sampling stations in different land-uses were selected for the study. Concentrations of Cd and Pb in liver and whole body concentration as well as concentration of Zn in hair of male rats were significantly higher than females. A significantly higher concentration was only observed for Pb in kidney of male gerbils than females. In numerous cases, age had significantly negative correlations with concentration of metals in different tissues of both species, and was only significantly (and positively) correlated with the concentration of Cd in kidney and Zn in liver of gerbils. This finding may indicate that the early neonatal age is a critical period for metals accumulation. The relationships between nutritional status and metal concentrations for both species were negative, which can be ascribed to the weight-specific metabolic rate that cause to a relatively low uptake of metals per unit of body weight. No significant differences were observed for soil metals concentrations in different sites. So, this suggests that the influence of life history, microhabitat use and foraging behavior did significantly influence on inter and intra specific variation of metals concentration in small mammals. Our observations suggest that hair cannot be used alone for monitoring exposure of metals.

  19. Heavy metal concentrations in diploid and triploid oysters (Crassostrea gigas) from three farms on the north-central coast of Sinaloa, Mexico.

    PubMed

    Muñoz Sevilla, Norma Patricia; Villanueva-Fonseca, Brenda Paulina; Góngora-Gómez, Andrés Martin; García-Ulloa, Manuel; Domínguez-Orozco, Ana Laura; Ortega-Izaguirre, Rogelio; Campos Villegas, Lorena Elizabeth

    2017-10-03

    The concentrations of Cu, Cd, Pb, Zn, and Hg in diploid and triploid oysters from three farms (Guasave, Ahome, and Navolato) on the north-central coast of Sinaloa, Mexico, were assessed based on samples recovered during a single culture cycle 2013-2014. Metal burdens were more strongly correlated (p < 0.05) with the location of the farm than with either the ploidy or the interaction of both variables. The metal concentration ranking for oysters of both ploidies from the three farms was Zn > Cu > Cd > Pb > Hg. For all three farms, the mean concentrations of Cd and Pb in Crassostrea gigas were high, ranging from 2.52 to 7.98 μg/g wet weight for Cd and from 0.91 to 2.83 μg/g wet weight for Pb. Diploid and triploid oysters from the Guasave farm contained high levels of Cu (76.41 and 68.97 μg/g wet weight, respectively). Cu, Cd, and Zn were highly correlated (p < 0.05), and their concentrations may be influenced by agrochemical inputs. The mean levels of Cu for the Guasave farm and of Cd and Pb for all three farms exceeded permissible limits and represented a threat to human health during the sampling period (July 2014 to July 2014).

  20. Calculating cellulose diffraction patterns

    USDA-ARS?s Scientific Manuscript database

    Although powder diffraction of cellulose is a common experiment, the patterns are not widely understood. The theory is mathematical, there are numerous different crystal forms, and the conventions are not standardized. Experience with IR spectroscopy is not directly transferable. An awful error, tha...

  1. DIFFRACTION FROM MODEL CRYSTALS

    USDA-ARS?s Scientific Manuscript database

    Although calculating X-ray diffraction patterns from atomic coordinates of a crystal structure is a widely available capability, calculation from non-periodic arrays of atoms has not been widely applied to cellulose. Non-periodic arrays result from modeling studies that, even though started with at...

  2. Diffract, then destroy

    NASA Astrophysics Data System (ADS)

    Ball, Philip

    2016-09-01

    A new implementation of X-ray diffraction using free-electron lasers can take snapshots of biological molecules that are inaccessible via X-ray crystallography. As Philip Ball reports, the technique can even be used to create stop-motion films of dynamic molecular processes

  3. Inclusive diffraction at HERA

    SciTech Connect

    Favart, Laurent

    2011-07-15

    Results are reported on recent measurements, performed by the H1 and ZEUS Collaborations, of the cross section of the diffractive deep-inelastic process ep{yields}eXp using different experimental methods. In particular, first results using the Very Forward Proton Spectrometer of H1 are discussed.

  4. Diffraction pattern study for cell type identification.

    PubMed

    Mihailescu, M; Costescu, J

    2012-01-16

    This paper presents our study regarding diffracted intensity distribution in Fresnel and Fraunhofer approximation from different cell types. Starting from experimental information obtained through digital holographic microscopy, we modeled the cell shapes as oblate spheroids and built their phase-only transmission functions. In Fresnel approximation, the experimental and numerical diffraction patterns from mature and immature red blood cells have complementary central intensity values at different distances. The Fraunhofer diffraction patterns of deformed red blood cells were processed in the reciprocal space where, the isoamplitude curves were formed independently for each degree of cell deformation present within every sample; the values on each separate isoamplitude curve are proportional with the percentage of the respective cell type within the sample.

  5. A Heavy Flavor Tracker for STAR

    SciTech Connect

    Xu, Z.; Chen, Y.; Kleinfelder, S.; Koohi, A.; Li, S.; Huang, H.; Tai, A.; Kushpil, V.; Sumbera, M.; Colledani, C.; Dulinski, W.; Himmi,A.; Hu, C.; Shabetai, A.; Szelezniak, M.; Valin, I.; Winter, M.; Surrow,B.; Van Nieuwenhuizen, G.; Bieser, F.; Gareus, R.; Greiner, L.; Lesser,F.; Matis, H.S.; Oldenburg, M.; Ritter, H.G.; Pierpoint, L.; Retiere, F.; Rose, A.; Schweda, K.; Sichtermann, E.; Thomas, J.H.; Wieman, H.; Yamamoto, E.; Kotov, I.

    2005-03-14

    We propose to construct a Heavy Flavor Tracker (HFT) for the STAR experiment at RHIC. The HFT will bring new physics capabilities to STAR and it will significantly enhance the physics capabilities of the STAR detector at central rapidities. The HFT will ensure that STAR will be able to take heavy flavor data at all luminosities attainable throughout the proposed RHIC II era.

  6. A Heavy Flavor Tracker for STAR

    SciTech Connect

    Xu, Z.; Chen, Y.; Kleinfelder, S.; Koohi, A.; Li, S.; Huang, H.; Tai, A.; Kushpil, V.; Sumbera, M.; Colledani, C.; Dulinski, W.; Himmi,A.; Hu, C.; Shabetai, A.; Szelezniak, M.; Valin, I.; Winter, M.; Miller,M.; Surrow, B.; Van Nieuwenhuizen G.; Bieser, F.; Gareus, R.; Greiner,L.; Lesser, F.; Matis, H.S.; Oldenburg, M.; Ritter, H.G.; Pierpoint, L.; Retiere, F.; Rose, A.; Schweda, K.; Sichtermann, E.; Thomas, J.H.; Wieman, H.; Yamamoto, E.; Kotov, I.

    2005-03-14

    We propose to construct a Heavy Flavor Tracker (HFT) for theSTAR experiment at RHIC. The HFT will bring new physics capabilities toSTAR and it will significantly enhance the physics capabilities of theSTAR detector at central rapidities. The HFT will ensure that STAR willbe able to take heavy flavor data at all luminosities attainablethroughout the proposed RHIC II era.

  7. SINGLE CRYSTAL NEUTRON DIFFRACTION.

    SciTech Connect

    KOETZLE,T.F.

    2001-03-13

    Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for information on magnetic scattering of neutrons see Unit 14.3. Instruments for single-crystal diffraction (single-crystal diffractometers or SCDs) are generally available at the major neutron scattering center facilities. Beam time on many of these instruments is available through a proposal mechanism. A listing of neutron SCD instruments and their corresponding facility contacts is included in an appendix accompanying this unit.

  8. SINGLE CRYSTAL NEUTRON DIFFRACTION.

    SciTech Connect

    KOETZLE,T.F.

    2001-03-13

    Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for information on magnetic scattering of neutrons see Unit 14.3. Instruments for single-crystal diffraction (single-crystal diffractometers or SCDs) are generally available at the major neutron scattering center facilities. Beam time on many of these instruments is available through a proposal mechanism. A listing of neutron SCD instruments and their corresponding facility contacts is included in an appendix accompanying this unit.

  9. Diffraction before destruction

    PubMed Central

    Chapman, Henry N.; Caleman, Carl; Timneanu, Nicusor

    2014-01-01

    X-ray free-electron lasers have opened up the possibility of structure determination of protein crystals at room temperature, free of radiation damage. The femtosecond-duration pulses of these sources enable diffraction signals to be collected from samples at doses of 1000 MGy or higher. The sample is vaporized by the intense pulse, but not before the scattering that gives rise to the diffraction pattern takes place. Consequently, only a single flash diffraction pattern can be recorded from a crystal, giving rise to the method of serial crystallography where tens of thousands of patterns are collected from individual crystals that flow across the beam and the patterns are indexed and aggregated into a set of structure factors. The high-dose tolerance and the many-crystal averaging approach allow data to be collected from much smaller crystals than have been examined at synchrotron radiation facilities, even from radiation-sensitive samples. Here, we review the interaction of intense femtosecond X-ray pulses with materials and discuss the implications for structure determination. We identify various dose regimes and conclude that the strongest achievable signals for a given sample are attained at the highest possible dose rates, from highest possible pulse intensities. PMID:24914146

  10. Polychromatic diffraction contrast tomography

    SciTech Connect

    King, A.; Reischig, P.; Adrien, J.; Peetermans, S.; Ludwig, W.

    2014-11-15

    This tutorial review introduces the use of polychromatic radiation for 3D grain mapping using X-ray diffraction contrast tomography. The objective is to produce a 3D map of the grain shapes and orientations within a bulk, millimeter-sized polycrystalline sample. The use of polychromatic radiation enables the standard synchrotron X-ray technique to be applied in a wider range of contexts: 1) Using laboratory X-ray sources allows a much wider application of the diffraction contrast tomography technique. 2) Neutron sources allow large samples, or samples containing high Z elements to be studied. 3) Applied to synchrotron sources, smaller samples may be treated, or faster measurements may be possible. Challenges and particularities in the data acquisition and processing, and the limitations of the different variants, are discussed. - Highlights: • We present a tutorial review of polychromatic diffraction contrast tomography techniques. • The use of polychromatic radiation allows the standard synchrotron DCT technique to be extended to a range of other sources. • The characteristics and limitations of all variants of the techniques are derived, discussed and compared. • Examples using laboratory X-ray and cold neutron radiation are presented. • Suggestions for the future development of these techniques are presented.

  11. QCD and hard diffraction at the LHC

    SciTech Connect

    Albrow, Michael G.; /Fermilab

    2005-09-01

    As an introduction to QCD at the LHC the author gives an overview of QCD at the Tevatron, emphasizing the high Q{sup 2} frontier which will be taken over by the LHC. After describing briefly the LHC detectors the author discusses high mass diffraction, in particular central exclusive production of Higgs and vector boson pairs. The author introduces the FP420 project to measure the scattered protons 420m downstream of ATLAS and CMS.

  12. Electron Diffraction from Surfaces with Atomic Steps

    NASA Astrophysics Data System (ADS)

    Lent, Craig Stanley

    The presence of atomic steps on solid surfaces is important in catalysis, crystal growth and dissolution processes. Because of the decreased coordination of atoms at step edges, these sites are frequently more reactive than others. Knowledge of the step distribution on the surface is required in order to adequately incorporate the effects of steps in models of physical processes. We examine the sensitivity of electron diffraction, particularly Reflection High Energy Electron Diffraction (RHEED), to the atomic step distribution on the surface. The RHEED instrument response length is considerably larger than other diffraction instruments, making it particularly suited for studying surface steps. Several calculations are presented to assess the effect of various step distributions on the intensity profiles of diffracted beams at various angles of incidence. The geometric distribution of steps corresponds to the limit of no interactions between step edges. A Markov matrix method of calculating the diffracted intensity from a geometric distribution of surface steps is presented. This reduces the calculation to a simple eigenvalue problem. The diffracted intensity profile is the sum of a sharp central spike, corresponding to the instrument response function, and several Lorenztians, whose widths are related to the eigenvalues of the matrix describing the distribution. The Markov approach also leads to the important distinction between reversible and irreversible step distributions. More general calculations, valid for any step distribution reveal that the separation into a central spike and step-broadened terms is retained. The shapes of the broad terms depend on the details of the distribution. The relative contributions of the step-broadened parts and the central spike vary as incident angle is changed and depend on the surface coverage. RHEED beam profiles have been measured from surfaces prepared by Molecular Beam Epitaxy. Submonolayer amounts of GaAs and AlAs were

  13. Heavy particle production at the SSC

    SciTech Connect

    Brodsky, S.J.; Haber, H.E.; Gunion, J.F.

    1984-03-01

    Predictions for the production of heavy quarks, supersymmetric particles, and other colored systems at high energy due to intrinsic twist-six components in the proton wavefunction are given. We also suggest the possibility of using asymmetric collision energies (e.g., via intersecting rings at the SSC) in order to facilitate the study of forward and diffractive particle production processes. 9 references.

  14. The Rhodope Zone as a primary sediment source of the southern Thrace basin (NE Greece and NW Turkey): evidence from detrital heavy minerals and implications for central-eastern Mediterranean palaeogeography

    NASA Astrophysics Data System (ADS)

    Caracciolo, L.; Critelli, S.; Cavazza, W.; Meinhold, G.; von Eynatten, H.; Manetti, P.

    2015-04-01

    Detrital heavy mineral analysis coupled with a regional geological review provide key elements to re-evaluate the distribution of the Rhodope metamorphic zone (SE Europe) in the region and its role in determining the evolution of the Thrace basin. We focus on the Eocene-Oligocene sedimentary successions exposed in the southern Thrace basin margin to determine the dispersal pathways of eroded crustal elements, of both oceanic and continental origins, as well as their different contributions through time. Lithological aspects and tectonic data coupled with geochemistry and geochronology of metamorphic terranes exposed in the area point to a common origin of tectonic units exposed in NW Turkey (Biga Peninsula) with those of NE Greece and SE Bulgaria (Rhodope region). The entire region displays (1) common extensional signatures, consisting of comparable granitoid intrusion ages, and a NE-SW sense of shear (2) matching zircon age populations between the metapelitic and metamafic rocks of the Circum-Rhodope Belt (NE Greece) and those of the Çamlica-Kemer complex and Çetmi mélange exposed in NW Turkey. Detrital heavy mineral abundances from Eocene-Oligocene sandstones of the southern Thrace basin demonstrate the influence of two main sediment sources mostly of ultramafic/ophiolitic and low- to medium-grade metamorphic lithologies, plus a third, volcanic source limited to the late Eocene-Oligocene. Detrital Cr-spinel chemistry is used to understand the origin of the ultramafic material and to discriminate the numerous ultramafic sources exposed in the region. Compositional and stratigraphic data indicate a major influence of the metapelitic source in the eastern part (Gallipoli Peninsula) during the initial stages of sedimentation with increasing contributions from metamafic sources through time. On the other hand, the western and more external part of the southern Thrace margin (Gökçeada, Samothraki and Limnos) displays compositional signatures according to a mixed

  15. Open Heavy Flavor Measurements in Heavy Ion Collisions with CMS

    NASA Astrophysics Data System (ADS)

    Sun, Jian

    2016-12-01

    The measurement of heavy flavor production is a powerful tool to study the properties of the high-density QCD medium created in heavy-ion collisions as heavy quarks are sensitive to the transport properties of the medium and may interact with the matter differently than light quarks. Heavy flavor jets, non-prompt J / ψ (J / ψ from B-hadron decay) and fully reconstructed B mesons have been studied in PbPb collisions at 2.76 TeV and pPb collisions at 5.02 TeV with CMS. Recently, the nuclear modification factor of prompt D0 mesons has been measured in PbPb collisions at 2.76 TeV with CMS as a function of both transverse momentum and collision centrality. These studies show that prompt D0 production is suppressed in semi-central to central PbPb collisions and the suppression is smaller at high pT. A comparison with the RAA of charged particle and non-prompt J / ψ hints a hierarchy of suppression as a function of flavor.

  16. Diffraction of a Laser Beam.

    ERIC Educational Resources Information Center

    Jodoin, Ronald E.

    1979-01-01

    Investigates the effect of the nonuniform irradiance across a laser beam on diffraction of the beam, specifically the Fraunhofer diffraction of a laser beam with a Gaussian irradiance profile as it passes through a circular aperture. (GA)

  17. Diffractive Alvarez lens

    SciTech Connect

    Barton, Ian M.; Dixit, Sham N.; Summers, Leslie J.; Thompson, Charles A.; Avicola, Kenneth; Wilhelmsen, Julia

    2000-01-01

    A diffractive Alvarez lens is demonstrated that consists of two separate phase plates, each having complementary 16-level surface-relief profiles that contain cubic phase delays. Translation of these two components in the plane of the phase plates is shown to produce a variable astigmatic focus. Both spherical and cylindrical phase profiles are demonstrated with good accuracy, and the discrete surface-relief features are shown to cause less than {lambda}/10 wave-front aberration in the transmitted wave front over a 40 mmx80 mm region. (c) 2000 Optical Society of America.

  18. Diffraction from materials

    SciTech Connect

    Schwartz, L.H.; Cohen, J.B.

    1987-01-01

    This is a completely revised second edition and is intended as a text in diffraction. The book presents elementary topics on scattering and crystallography and expands on concepts in later chapters which focus on defects in solids, scattering from perfect solids, and crystal structure determination. The first half of the book may be used as an introductory text for juniors or seniors in college, while the second half is suitable for a graduate-level course or for use as a monograph. The new edition simplifies the introduction to crystallography, introduces concepts required by the advent of synchrotron radiation and pulsed reaction sources, and updates the subject matter dealing with defects in solids.

  19. Transurethral Ultrasound Diffraction Tomography

    DTIC Science & Technology

    2007-03-01

    transmitter. These are then 7 Fourier transformed into the frequency domain data. The clock rate is 33 MHz, and the FFT is performed after 1536 time...B. Yazgan and O.K. Ersoy, Multistage parallel algorithm for diffraction tomography, Applied Optica , vol. 34, pp, 1426-1431, 1995. [9] J. Wiskin, D.T...J1k0a2. Note that Eq. 34 reflects the well-known fact that in the Born approxi- mation the Fourier frequencies of the object are confined within a

  20. A rational approach to heavy-atom derivative screening.

    PubMed

    Joyce, M Gordon; Radaev, Sergei; Sun, Peter D

    2010-04-01

    Despite the development in recent times of a range of techniques for phasing macromolecules, the conventional heavy-atom derivatization method still plays a significant role in protein structure determination. However, this method has become less popular in modern high-throughput oriented crystallography, mostly owing to its trial-and-error nature, which often results in lengthy empirical searches requiring large numbers of well diffracting crystals. In addition, the phasing power of heavy-atom derivatives is often compromised by lack of isomorphism or even loss of diffraction. In order to overcome the difficulties associated with the 'classical' heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom derivative-screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. The method includes three basic steps: (i) the selection of likely reactive compounds for a given protein and specific crystallization conditions based on pre-defined heavy-atom compound reactivity profiles, (ii) screening of the chosen heavy-atom compounds for their ability to form protein adducts using mass spectrometry and (iii) derivatization of crystals with selected heavy-metal compounds using the quick-soak method to maximize diffraction quality and minimize non-isomorphism. Overall, this system streamlines the process of heavy-atom compound identification and minimizes the problem of non-isomorphism in phasing.

  1. Electron diffraction from cylindrical nanotubes

    SciTech Connect

    Qin, L.C. )

    1994-09-01

    Electron diffraction intensities from cylindrical objects can be conveniently analyzed using Bessel functions. Analytic formulas and geometry of the diffraction patterns from cylindrical carbon nanotubes are presented in general forms in terms of structural parameters, such as the pitch angle and the radius of a tubule. As an example the Fraunhofer diffraction pattern from a graphitic tubule of structure [18,2] has been simulated to illustrate the characteristics of such diffraction patterns. The validity of the projection approximation is also discussed.

  2. Design the diffractive optical element with large diffraction angle

    NASA Astrophysics Data System (ADS)

    Pang, Hui; Yin, Shaoyun; Zheng, Guoxing; Deng, Qiling; Shi, Lifang; Du, Chunlei

    2014-11-01

    In this paper, a quite effective method is proposed for designing the diffractive optical element (DOE) to generate a pattern with large diffraction angle. Through analyze the difference between the non-paraxial Rayleigh Sommerfeld integral and the paraxial Fraunhofer diffraction integral, we modify the desired output intensity distribution with coordinate transformation and intensity adjustment. Then the paraxial Fraunhofer diffraction integral can be used to design the DOE, which adopts the fast-Fourier-transform (FFT) algorithm to accelerate the computation. To verify our method, the simulation and the experiments are taken. And the result shows that our method can effectively rectify the pillow distortion and can achieve the exact diffraction angle.

  3. Aberrations of diffracted wave fields. II. Diffraction gratings.

    PubMed

    Mahajan, V N

    2000-12-01

    The Rayleigh-Sommerfeld theory is applied to diffraction of a spherical wave by a grating. The grating equation is obtained from the aberration-free diffraction pattern, and its aberrations are shown to be the same as the conventional aberrations obtained by using Fermat's principle. These aberrations are shown to be not associated with the diffraction process. Moreover, it is shown that the irradiance distribution of a certain diffraction order is the Fraunhofer diffraction pattern of the grating aperture as a whole aberrated by the aberration of that order.

  4. DPEMC: A Monte Carlo for double diffraction

    NASA Astrophysics Data System (ADS)

    Boonekamp, M.; Kúcs, T.

    2005-05-01

    We extend the POMWIG Monte Carlo generator developed by B. Cox and J. Forshaw, to include new models of central production through inclusive and exclusive double Pomeron exchange in proton-proton collisions. Double photon exchange processes are described as well, both in proton-proton and heavy-ion collisions. In all contexts, various models have been implemented, allowing for comparisons and uncertainty evaluation and enabling detailed experimental simulations. Program summaryTitle of the program:DPEMC, version 2.4 Catalogue identifier: ADVF Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADVF Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Computer: any computer with the FORTRAN 77 compiler under the UNIX or Linux operating systems Operating system: UNIX; Linux Programming language used: FORTRAN 77 High speed storage required:<25 MB No. of lines in distributed program, including test data, etc.: 71 399 No. of bytes in distributed program, including test data, etc.: 639 950 Distribution format: tar.gz Nature of the physical problem: Proton diffraction at hadron colliders can manifest itself in many forms, and a variety of models exist that attempt to describe it [A. Bialas, P.V. Landshoff, Phys. Lett. B 256 (1991) 540; A. Bialas, W. Szeremeta, Phys. Lett. B 296 (1992) 191; A. Bialas, R.A. Janik, Z. Phys. C 62 (1994) 487; M. Boonekamp, R. Peschanski, C. Royon, Phys. Rev. Lett. 87 (2001) 251806; Nucl. Phys. B 669 (2003) 277; R. Enberg, G. Ingelman, A. Kissavos, N. Timneanu, Phys. Rev. Lett. 89 (2002) 081801; R. Enberg, G. Ingelman, L. Motyka, Phys. Lett. B 524 (2002) 273; R. Enberg, G. Ingelman, N. Timneanu, Phys. Rev. D 67 (2003) 011301; B. Cox, J. Forshaw, Comput. Phys. Comm. 144 (2002) 104; B. Cox, J. Forshaw, B. Heinemann, Phys. Lett. B 540 (2002) 26; V. Khoze, A. Martin, M. Ryskin, Phys. Lett. B 401 (1997) 330; Eur. Phys. J. C 14 (2000) 525; Eur. Phys. J. C 19 (2001) 477; Erratum, Eur. Phys. J. C 20 (2001) 599; Eur

  5. Diffractive physics results at CDF

    SciTech Connect

    Michele Gallinaro

    2003-12-18

    Forward detectors are described together with the first physics results from Run II. Using new data and dedicated diffractive triggers, a measurement of single diffractive dijet production rate, with particular focus on the diffractive structure function of the antiproton, is discussed. Upper limits on the exclusive dijet and {chi}{sub c}{sup 0} production cross sections are also presented.

  6. Spectral diffraction efficiency characterization of broadband diffractive optical elements.

    SciTech Connect

    Choi, Junoh; Cruz-Cabrera, Alvaro Augusto; Tanbakuchi, Anthony

    2013-03-01

    Diffractive optical elements, with their thin profile and unique dispersion properties, have been studied and utilized in a number of optical systems, often yielding smaller and lighter systems. Despite the interest in and study of diffractive elements, the application has been limited to narrow spectral bands. This is due to the etch depths, which are optimized for optical path differences of only a single wavelength, consequently leading to rapid decline in efficiency as the working wavelength shifts away from the design wavelength. Various broadband diffractive design methodologies have recently been developed that improve spectral diffraction efficiency and expand the working bandwidth of diffractive elements. We have developed diffraction efficiency models and utilized the models to design, fabricate, and test two such extended bandwidth diffractive designs.

  7. Radial reflection diffraction tomography

    NASA Astrophysics Data System (ADS)

    Lehman, Sean K.; Norton, Stephen J.

    2004-10-01

    A wave-based tomographic imaging algorithm based upon a single rotating radially outward oriented transducer is developed. At successive angular locations at a fixed radius, the transducer launches a primary field and collects the backscattered field in a ``pitch/catch'' operation. The hardware configuration, operating mode, and data collection method are identical to that of most medical intravascular ultrasound (IVUS) systems. IVUS systems form images of the medium surrounding the probe based upon ultrasonic B scans, using a straight-ray model of sound propagation. The goal of this research is to develop a wave-based imaging algorithm using diffraction tomography techniques. Given the hardware configuration and the imaging method, this system is referred to as ``radial reflection diffraction tomography.'' Two hardware configurations are considered: a multimonostatic mode using a single transducer as described above, and a multistatic mode consisting of a single transmitter and an aperture formed by multiple receivers. In this latter case, the entire source/receiver aperture rotates about the fixed radius. Practically, such a probe is mounted at the end of a catheter or snaking tube that can be inserted into a part or medium with the goal of forming images of the plane perpendicular to the axis of rotation. An analytic expression for the multimonostatic inverse is derived, but ultimately the new Hilbert space inverse wave (HSIW) algorithm is used to construct images using both operating modes. Applications include improved IVUS imaging, bore hole tomography, and nondestructive evaluation (NDE) of parts with existing access holes. .

  8. Radial Reflection Diffraction Tomography

    SciTech Connect

    Lehman, S K; Norton, S J

    2003-10-10

    We develop a wave-based tomographic imaging algorithm based upon a single rotating radially outward oriented transducer. At successive angular locations at a fixed radius, the transducer launches a primary field and collects the backscattered field in a ''pitch/catch'' operation. The hardware configuration, operating mode, and data collection method is identical to that of most medical intravascular ultrasound (IVUS) systems. IVUS systems form images of the medium surrounding the probe based upon ultrasonic B-scans, using a straight-ray model of sound propagation. Our goal is to develop a wave-based imaging algorithm using diffraction tomography techniques. Given the hardware configuration and the imaging method, we refer to this system as ''radial reflection diffraction tomography.'' We consider two hardware configurations: a multimonostatic mode using a single transducer as described above, and a multistatic mode consisting of a single transmitter and an aperture formed by multiple receivers. In this latter case, the entire source/receiver aperture rotates about the fixed radius. Practically, such a probe is mounted at the end of a catheter or snaking tube that can be inserted into a part or medium with the goal of forming images of the plane perpendicular to the axis of rotation. We derive an analytic expression for the multimonostatic inverse but ultimately use the new Hilbert space inverse wave (HSIW) algorithm to construct images using both operating modes. Applications include improved IVUS imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts with existing access holes.

  9. Relativistic heavy ion facilities: worldwide

    SciTech Connect

    Schroeder, L.S.

    1986-05-01

    A review of relativistic heavy ion facilities which exist, are in a construction phase, or are on the drawing boards as proposals is presented. These facilities span the energy range from fixed target machines in the 1 to 2 GeV/nucleon regime, up to heavy ion colliders of 100 GeV/nucleon on 100 GeV/nucleon. In addition to specifying the general features of such machines, an outline of the central physics themes to be carried out at these facilities is given, along with a sampling of the detectors which will be used to extract the physics. 22 refs., 17 figs., 3 tabs.

  10. Evidence for color fluctuations in hadrons from coherent nuclear diffraction

    SciTech Connect

    Frankfurt, L. ); Miller, G.A. ); Strikman, M. )

    1993-11-01

    A QCD-based treatment of projectile size fluctuations is used to compute inelastic diffractive cross sections [sigma][sub diff] for coherent hadron-nuclear processes. We find that fluctuations near the average size give the major contribution to the cross section with [lt] few % contribution from small size configurations. The computed values of [sigma][sub diff] are consistent with the limited available data. The importance of coherent diffraction studies for a wide range of projectiles for high energy Fermilab fixed target experiments is emphasized. The implications of these significant color fluctuations for relativistic heavy ion collisions are discussed.

  11. Multilayer diffraction grating

    DOEpatents

    Barbee, T.W. Jr.

    1990-04-10

    This invention is for a reflection diffraction grating that functions at X-ray to VUV wavelengths and at normal angles of incidence. The novel grating is comprised of a laminar grating of period D with flat-topped grating bars. A multiplicity of layered synthetic microstructures, of period d and comprised of alternating flat layers of two different materials, are disposed on the tops of the grating bars of the laminar grating. In another embodiment of the grating, a second multiplicity of layered synthetic microstructures are also disposed on the flat faces, of the base of the grating, between the bars. D is in the approximate range from 3,000 to 50,000 Angstroms, but d is in the approximate range from 10 to 400 Angstroms. The laminar grating and the layered microstructures cooperatively interact to provide many novel and beneficial instrumentational advantages. 2 figs.

  12. Multilayer diffraction grating

    DOEpatents

    Barbee, Jr., Troy W.

    1990-01-01

    This invention is for a reflection diffraction grating that functions at X-ray to VUV wavelengths and at normal angles of incidence. The novel grating is comprised of a laminar grating of period D with flat-topped grating bars. A multiplicity of layered synthetic microstructures, of period d and comprised of alternating flat layers of two different materials, are disposed on the tops of the grating bars of the laminar grating. In another embodiment of the grating, a second multiplicity of layered synthetic microstructures are also disposed on the flat faces, of the base of the grating, between the bars. D is in the approximate range from 3,000 to 50,000 Angstroms, but d is in the approximate range from 10 to 400 Angstroms. The laminar grating and the layered microstructures cooperatively interact to provide many novel and beneficial instrumentational advantages.

  13. Birefringent coherent diffraction imaging

    NASA Astrophysics Data System (ADS)

    Karpov, Dmitry; dos Santos Rolo, Tomy; Rich, Hannah; Kryuchkov, Yuriy; Kiefer, Boris; Fohtung, E.

    2016-10-01

    Directional dependence of the index of refraction contains a wealth of information about anisotropic optical properties in semiconducting and insulating materials. Here we present a novel high-resolution lens-less technique that uses birefringence as a contrast mechanism to map the index of refraction and dielectric permittivity in optically anisotropic materials. We applied this approach successfully to a liquid crystal polymer film using polarized light from helium neon laser. This approach is scalable to imaging with diffraction-limited resolution, a prospect rapidly becoming a reality in view of emergent brilliant X-ray sources. Applications of this novel imaging technique are in disruptive technologies, including novel electronic devices, in which both charge and spin carry information as in multiferroic materials and photonic materials such as light modulators and optical storage.

  14. Multilayer diffraction grating

    SciTech Connect

    Barbee, T.W., Jr.

    1988-10-18

    This invention is for a reflection diffraction grating that functions at x-ray to VUV wavelengths and at normal angles of incidence. The novel grating is comprised of a laminar grating of period D with flat-topped grating bars. A multiplicity of layered synthetic microstructures, of period d and comprised of alternating flat layers of two different materials, are disposed on the tops of the grating bars of the laminar grating. In another embodiment of the grating, a second multiplicity of layered synthetic microstructures are also disposed on the flat faces, of the base of the grating, between the bars. D is in the approximate range from 3000 to 50,000 Angstroms, but d is in the approximate range from 10 to 400 Angstroms. The laminar grating and the layered microstructures cooperatively interact to provide many novel and beneficial instrumentational advantages. 2 figs.

  15. Phase shifting diffraction interferometer

    DOEpatents

    Sommargren, G.E.

    1996-08-29

    An interferometer which has the capability of measuring optical elements and systems with an accuracy of {lambda}/1000 where {lambda} is the wavelength of visible light. Whereas current interferometers employ a reference surface, which inherently limits the accuracy of the measurement to about {lambda}/50, this interferometer uses an essentially perfect spherical reference wavefront generated by the fundamental process of diffraction. This interferometer is adjustable to give unity fringe visibility, which maximizes the signal-to-noise, and has the means to introduce a controlled prescribed relative phase shift between the reference wavefront and the wavefront from the optics under test, which permits analysis of the interference fringe pattern using standard phase extraction algorithms. 8 figs.

  16. Phase shifting diffraction interferometer

    DOEpatents

    Sommargren, Gary E.

    1996-01-01

    An interferometer which has the capability of measuring optical elements and systems with an accuracy of .lambda./1000 where .lambda. is the wavelength of visible light. Whereas current interferometers employ a reference surface, which inherently limits the accuracy of the measurement to about .lambda./50, this interferometer uses an essentially perfect spherical reference wavefront generated by the fundamental process of diffraction. This interferometer is adjustable to give unity fringe visibility, which maximizes the signal-to-noise, and has the means to introduce a controlled prescribed relative phase shift between the reference wavefront and the wavefront from the optics under test, which permits analysis of the interference fringe pattern using standard phase extraction algorithms.

  17. Diffraction and Unitarity

    NASA Astrophysics Data System (ADS)

    Dremin, I. M.

    I begin with a tribute to V.N. Gribov and then come to a particular problem which would be of interest for him. His first paper on reggeology was devoted to elastic scatterings of hadrons. Here, using the unitarity relation in combination with experimental data about the elastic scattering in the diffraction cone, I show how the shape and the darkness of the interaction region of colliding protons change with the increase of their energies. In particular, the collisions become fully absorptive at small impact parameters at LHC energies that results in some special features of inelastic processes as well. The possible evolution with increasing energy of the shape from the dark core at the LHC to the fully transparent one at higher energies is discussed. It implies that the terminology of the black disk would be replaced by the black torus.

  18. Diffraction and unitarity

    NASA Astrophysics Data System (ADS)

    Dremin, I. M.

    2016-10-01

    I begin with a tribute to V.N. Gribov and then come to a particular problem which would be of interest for him. His first paper on reggeology was devoted to elastic scatterings of hadrons. Here, using the unitarity relation in combination with experimental data about the elastic scattering in the diffraction cone, I show how the shape and the darkness of the interaction region of colliding protons change with the increase of their energies. In particular, the collisions become fully absorptive at small impact parameters at LHC energies that results in some special features of inelastic processes as well. The possible evolution with increasing energy of the shape from the dark core at the LHC to the fully transparent one at higher energies is discussed. It implies that the terminology of the black disk would be replaced by the black torus.

  19. Dichroic coherent diffractive imaging

    PubMed Central

    Tripathi, Ashish; Mohanty, Jyoti; Dietze, Sebastian H.; Shpyrko, Oleg G.; Shipton, Erik; Fullerton, Eric E.; Kim, Sang Soo; McNulty, Ian

    2011-01-01

    Understanding electronic structure at the nanoscale is crucial to untangling fundamental physics puzzles such as phase separation and emergent behavior in complex magnetic oxides. Probes with the ability to see beyond surfaces on nanometer length and subpicosecond time scales can greatly enhance our understanding of these systems and will undoubtedly impact development of future information technologies. Polarized X-rays are an appealing choice of probe due to their penetrating power, elemental and magnetic specificity, and high spatial resolution. The resolution of traditional X-ray microscopes is limited by the nanometer precision required to fabricate X-ray optics. Here we present a novel approach to lensless imaging of an extended magnetic nanostructure, in which a scanned series of dichroic coherent diffraction patterns is recorded and numerically inverted to map its magnetic domain configuration. Unlike holographic methods, it does not require a reference wave or precision optics. In addition, it enables the imaging of samples with arbitrarily large spatial dimensions, at a spatial resolution limited solely by the coherent X-ray flux, wavelength, and stability of the sample with respect to the beam. It can readily be extended to nonmagnetic systems that exhibit circular or linear dichroism. We demonstrate this approach by imaging ferrimagnetic labyrinthine domains in a Gd/Fe multilayer with perpendicular anisotropy and follow the evolution of the domain structure through part of its magnetization hysteresis loop. This approach is scalable to imaging with diffraction-limited resolution, a prospect rapidly becoming a reality in view of the new generation of phenomenally brilliant X-ray sources. PMID:21825152

  20. Dichroic Coherent Diffractive Imaging

    NASA Astrophysics Data System (ADS)

    Tripathi, Ashish

    Understanding electronic structure at nanometer resolution is crucial to understanding physics such as phase separation and emergent behavior in correlated electron materials. Nondestructive probes which have the ability to see beyond surfaces on nanometer length and sub-picosecond time scales can greatly enhance our understanding of these systems and will impact development of future technologies, such as magnetic storage. Polarized x-rays are an appealing choice of probe due to their penetrating power, elemental and magnetic specificity, and high spatial resolution. The resolution of traditional x-ray microscopy is limited by the nanometer precision required to fabricate x-ray optics. In this thesis, a novel approach to lensless imaging of an extended magnetic nanostructure is presented. We demonstrate this approach by imaging ferrimagnetic "maze" domains in a Gd/Fe multilayer with perpendicular anisotropy. A series of dichroic coherent diffraction patterns, ptychographically recorded, are numerically inverted using non-convex and non-linear optimization theory, and we follow the magnetic domain configuration evolution through part of its magnetization hysteresis loop by applying an external magnetic field. Unlike holographic methods, it does not require a reference wave or precision optics, and so is a far simpler experiment. In addition, it enables the imaging of samples with arbitrarily large spatial dimensions, at a spatial resolution limited solely by the coherent x-ray flux and wavelength. It can readily be extended to other non-magnetic systems that exhibit circular or linear dichroism. This approach is scalable to imaging with diffraction-limited resolution, a prospect rapidly becoming a reality in view of the new generation of phenomenally brilliant x-ray sources.

  1. Dichroic coherent diffractive imaging.

    PubMed

    Tripathi, Ashish; Mohanty, Jyoti; Dietze, Sebastian H; Shpyrko, Oleg G; Shipton, Erik; Fullerton, Eric E; Kim, Sang Soo; McNulty, Ian

    2011-08-16

    Understanding electronic structure at the nanoscale is crucial to untangling fundamental physics puzzles such as phase separation and emergent behavior in complex magnetic oxides. Probes with the ability to see beyond surfaces on nanometer length and subpicosecond time scales can greatly enhance our understanding of these systems and will undoubtedly impact development of future information technologies. Polarized X-rays are an appealing choice of probe due to their penetrating power, elemental and magnetic specificity, and high spatial resolution. The resolution of traditional X-ray microscopes is limited by the nanometer precision required to fabricate X-ray optics. Here we present a novel approach to lensless imaging of an extended magnetic nanostructure, in which a scanned series of dichroic coherent diffraction patterns is recorded and numerically inverted to map its magnetic domain configuration. Unlike holographic methods, it does not require a reference wave or precision optics. In addition, it enables the imaging of samples with arbitrarily large spatial dimensions, at a spatial resolution limited solely by the coherent X-ray flux, wavelength, and stability of the sample with respect to the beam. It can readily be extended to nonmagnetic systems that exhibit circular or linear dichroism. We demonstrate this approach by imaging ferrimagnetic labyrinthine domains in a Gd/Fe multilayer with perpendicular anisotropy and follow the evolution of the domain structure through part of its magnetization hysteresis loop. This approach is scalable to imaging with diffraction-limited resolution, a prospect rapidly becoming a reality in view of the new generation of phenomenally brilliant X-ray sources.

  2. Strange dibaryon production in relativistic heavy ion collisions

    SciTech Connect

    Dover, C.B.

    1988-01-01

    We review theoretical predictions for the mass spectrum of strange dibaryons, with emphasis on S = /minus/2 states. In a version of the Callen-Klebanov model applied to dibaryons, the lowest-lying configuration is an SU(3) flavor (10*) with J/sup ..pi../ = O/sup +/ and isospin I = 1, in contrast to the six-quark (Q/sup 6/) bag model, which yields the H dibaryon (flavor (1), J/sup ..pi../ = O/sup +/, I = O) as the lowest S = /minus/2 excitation. Possible experimental consequences of this difference level order are discussed. For the H, we discuss formation rates in relativistic heavy ion collisions. For Brookhaven AGS energies (15 GeV/A), we find a rate of order 10/sup /minus/2/ H's per central collision. Since the H is produced in a high multiplicity environment in heavy ion collisions, its detection poses a problem. Several possible detection schemes for the H are investigated. These include studies of weak decays (..sigma../sup minus/p ''vees''), diffractive dissociation (Hp ..-->.. ..lambda lambda..p ..-->.. 3p + 2..pi../sup /minus//) and nuclear fragments with anomalous charge/mass ratios. 40 refs., 5 figs., 2 tabs.

  3. Diffraction-based optical correlator

    NASA Technical Reports Server (NTRS)

    Spremo, Stevan M. (Inventor); Fuhr, Peter L. (Inventor); Schipper, John F. (Inventor)

    2005-01-01

    Method and system for wavelength-based processing of a light beam. A light beam, produced at a chemical or physical reaction site and having at least first and second wavelengths, ?1 and ?2, is received and diffracted at a first diffraction grating to provide first and second diffracted beams, which are received and analyzed in terms of wavelength and/or time at two spaced apart light detectors. In a second embodiment, light from first and second sources is diffracted and compared in terms of wavelength and/or time to determine if the two beams arise from the same source. In a third embodiment, a light beam is split and diffracted and passed through first and second environments to study differential effects. In a fourth embodiment, diffracted light beam components, having first and second wavelengths, are received sequentially at a reaction site to determine whether a specified reaction is promoted, based on order of receipt of the beams. In a fifth embodiment, a cylindrically shaped diffraction grating (uniform or chirped) is rotated and translated to provide a sequence of diffracted beams with different wavelengths. In a sixth embodiment, incident light, representing one or more symbols, is successively diffracted from first and second diffraction gratings and is received at different light detectors, depending upon the wavelengths present in the incident light.

  4. A rational approach to heavy-atom derivative screening

    SciTech Connect

    Joyce, M. Gordon; Radaev, Sergei; Sun, Peter D.

    2010-04-01

    In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom-derivative screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. Despite the development in recent times of a range of techniques for phasing macromolecules, the conventional heavy-atom derivatization method still plays a significant role in protein structure determination. However, this method has become less popular in modern high-throughput oriented crystallography, mostly owing to its trial-and-error nature, which often results in lengthy empirical searches requiring large numbers of well diffracting crystals. In addition, the phasing power of heavy-atom derivatives is often compromised by lack of isomorphism or even loss of diffraction. In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom derivative-screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. The method includes three basic steps: (i) the selection of likely reactive compounds for a given protein and specific crystallization conditions based on pre-defined heavy-atom compound reactivity profiles, (ii) screening of the chosen heavy-atom compounds for their ability to form protein adducts using mass spectrometry and (iii) derivatization of crystals with selected heavy-metal compounds using the quick-soak method to maximize diffraction quality and minimize non-isomorphism. Overall, this system streamlines the process of heavy-atom compound identification and minimizes the problem of non-isomorphism in phasing.

  5. Optical diffraction analysis of petrographic thin sections.

    PubMed

    Power, P C; Pincus, H J

    1974-10-18

    contain only elements of low spatial frequency that will not generate diffraction dots far enough radially from the central spot to be resolvable. More study will be needed to establish the precision of spatial frequency measurements from diffraction patterns generated directly by thin sections with the microscope system. Experiments with a variety of film types and sources of illumination will, in all likelihood, lead to a reduction in the exposure times used to record diffraction patterns with the microscope (9). A complete ODA system must have directional and frequency-filtering capabilities. In order to establish these capabilities for the microscope system, components will need to be designed and fabricated and the microscope body may have to be modified. The possibility of applying the microscope technique in reflected light on a real-time basis should be investigated. This would be a valuable tool in the quantitative analysis of microfracture initiation and propagation and the analysis of overall fabric changes during experimental deformation of rock both in situ and in the laboratory. The technique presented here can be used with a less expensive microscope, if it has a focusable Bertrand lens. Our experiments with relatively inexpensive microscopes indicated that the only major problem is alignment of the illuminating system (light-filter-condenser).

  6. High-Energy Diffraction-Enhanced X-ray Imaging

    SciTech Connect

    Yoneyama, Akio; Ueda, Kazuhiro; Takeda, Tohoru; Yamazaki, Takanori; Hyodo, Kazuyuki

    2010-06-23

    In order to apply the diffraction-enhanced X-ray imaging (DEI) method for much wider variety of samples, we have developed the high-energy DEI system. The energy of X-ray was increased up to 70 keV to achieve high permeability for heavy elements. The diffraction of Si(440) was used to keep large field of view. Demonstrative observation of an electrical cable was performed using the X-ray emitted from the vertical wiggler. The obtained images visualized not only the core and ground wire made of copper but also the isolator and outer jacket made of polymer clearly. The comparison of images obtained by the DEI and the absorption-contrast imaging showed that the sensitivity of DEI is about 10 times higher than that of the absorption method for light elements, and 3 times for heavy elements.

  7. Light diffraction by a particle on an optically smooth surface.

    PubMed

    Johnson, B R

    1997-01-01

    The differential cross section for radiation scattered by a particle that is large compared to the wavelength, and resting on an optically smooth surface, is characterized by an intense, narrow peak in the direction of the reflected beam. This peak is shown to be due mainly to Fraunhofer diffraction by the overlapping projections of the particle and its image on a plane perpendicular to the reflected beam. Results calculated with this simple diffraction theory are compared with accurate results calculated by the multipole expansion method. Simple analytic formulas are derived that characterize the width and height of the central diffraction peak.

  8. Design and demonstration of broadband thin planar diffractive acoustic lenses

    SciTech Connect

    Wang, Wenqi; Xie, Yangbo; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A.

    2014-09-08

    We present here two diffractive acoustic lenses with subwavelength thickness, planar profile, and broad operation bandwidth. Tapered labyrinthine unit cells with their inherently broadband effective material properties are exploited in our design. Both the measured and the simulated results are showcased to demonstrate the lensing effect over more than 40% of the central frequency. The focusing of a propagating Gaussian modulated sinusoidal pulse is also demonstrated. This work paves the way for designing diffractive acoustic lenses and more generalized phase engineering diffractive elements with labyrinthine acoustic metamaterials.

  9. Dual focus diffractive optical element with extended depth of focus

    NASA Astrophysics Data System (ADS)

    Uno, Katsuhiro; Shimizu, Isao

    2014-09-01

    A dual focus property and an extended depth of focus were verified by a new type of diffractive lens displaying on liquid crystal on silicon (LCoS) devices. This type of lens is useful to read information on multilayer optical discs and tilted discs. The radial undulation of the phase groove on the diffractive lens gave the dual focus nature. The focal extension was performed by combining the dual focus lens with the axilens that was invented for expanding the depth of focus. The number of undulations did not affect the intensity along the optical axis but the central spot of the diffraction pattern.

  10. Central exclusive production in the STAR experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Sikora, Rafal

    2017-03-01

    The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) performs studies of diffractive processes with the focus on the exclusive production of particles in central range of rapidity. In 2015 STAR collected 18 pb-1 of data in polarized proton+proton collisions at √{s }=200 GeV to measure Central Exclusive Production (CEP) process pp → pX p through Double Pomeron Exchange (DPE) mechanism. The intact protons moving inside the RHIC beampipe after the collision were measured in silicon strip detectors (SSD), which were placed in the Roman Pot vessels. This enables full control over interaction kinematics and verification of the exclusivity of the reaction by measuring the total (missing) transverse momenta of all final state particles: the central diffractive system in the Time Projection Chamber (TPC) and the forward protons in the Roman Pots. With the use of ionization energy loss in the TPC, dE/dx, it was possible to discriminate various production channels in pp → pX p reaction. This paper presents results on exclusive production of two charged particles (π+π- and K+ K-) in mid-rapidity region, -1 < η < 1, with small squared four-momentum transfer of forward protons, 0.03 < -t < 0.3 (GeV/c)2, obtained using 2.5% of full statistics.

  11. Diffraction at HFIR

    SciTech Connect

    Chakoumakos, Bryan C; Fernandez-Baca, Jaime A; Garlea, Vasile O; Hubbard, Camden R; Wang, Xun-Li

    2008-01-01

    Of the planned suite of powder and single-crystal diffractometers for the HFIR, only two are currently operating, the Neutron Residual Stress Mapping Facility (NRSF2) diffractometer, and the Wide Angle Neutron Diffractometer (WAND). The NSRF2 was recently upgraded and is available to external users via the High Temperature Materials Laboratory (HTML) User Program for studies of stress, texture and phase mapping. The WAND is a flat-cone geometry diffractometer equipped with a curve 1-D PSD, suitable for high intensity powder diffraction (e.g., kinetics, high pressure) and diffuse scattering studies of single-crystals. A rebuild of the old HFIR powder diffractometer, originally located at HB-4 station is now underway, and is expected to begin commissioning by summer 2008. This instrument has a Debye-Scherrer geometry, with a detector bank consisting of 44 3He tubes each with 6' Soller collimators. A four-circle single-crystal diffractometer is located at the HB-3A station, and is slowly being brought back to life after the long hiatus connected to the reactor upgrade. A Letter of Intent to build a quasi-Laue diffractometer, called IMAGINE, in the HFIR Cold Guide Hall has been presented to and endorsed by the Neutron Scattering Science Advisory Committee.

  12. Diffractive parameric colors.

    PubMed

    Orava, Joni; Heikkila, Noora; Jaaskelainen, Timo; Parkkinen, Jussi

    2008-12-01

    A method of producing inkless parameric color pairs is studied. In this method, colors are formed additively using diffraction gratings with differing grating periods as primary colors. Gratings with different grating periods reflect different spectral radiance peaks of a fluorescent lamp to the desired viewing angle, according to the grating equation. Four spectral peaks of a 4000 K fluorescent lamp--red, green, cyan, and blue-are used as the primary colors. The colors are mixed additively by fixing the relative areas of different grating periods inside a pixel. With four primary colors it is possible to mix certain colors with different triplets of primary colors. Thus, it is theoretically possible to produce metameric colors. In this study, three parameric color pairs are fabricated using electron beam lithography, electroplating, and hot embossing. The radiance spectra of the color pairs are measured by spectroradiometer from hot-embossed plastic samples. The CIELAB DeltaE(ab) and CIEDE2000 color differences between radiance spectra of the color pairs are calculated. The CIEDE2000 color differences of color pairs are between 2.6 and 7.2 units in reference viewing conditions. The effects of viewing angle and different light sources are also evaluated. It is found that both the viewing angle and the light source have very strong influences on the color differences of the color pairs.

  13. Study of optical Laue diffraction

    NASA Astrophysics Data System (ADS)

    Chakravarthy, Giridhar; Allam, Srinivasa Rao; Satyanarayana, S. V. M.; Sharan, Alok

    2014-10-01

    We present the study of the optical diffraction pattern of one and two-dimensional gratings with defects, designed using desktop pc and printed on OHP sheet using laser printer. Gratings so prepared, using novel low cost technique provides good visual aid in teaching. Diffraction pattern of the monochromatic light (632.8nm) from the grating so designed is similar to that of x-ray diffraction pattern of crystal lattice with point defects in one and two-dimensions. Here both optical and x-ray diffractions are Fraunhofer. The information about the crystalline lattice structure and the defect size can be known.

  14. Electrically-programmable diffraction grating

    DOEpatents

    Ricco, Antonio J.; Butler, Michael A.; Sinclair, Michael B.; Senturia, Stephen D.

    1998-01-01

    An electrically-programmable diffraction grating. The programmable grating includes a substrate having a plurality of electrodes formed thereon and a moveable grating element above each of the electrodes. The grating elements are electrostatically programmable to form a diffraction grating for diffracting an incident beam of light as it is reflected from the upper surfaces of the grating elements. The programmable diffraction grating, formed by a micromachining process, has applications for optical information processing (e.g. optical correlators and computers), for multiplexing and demultiplexing a plurality of light beams of different wavelengths (e.g. for optical fiber communications), and for forming spectrometers (e.g. correlation and scanning spectrometers).

  15. Study of optical Laue diffraction

    SciTech Connect

    Chakravarthy, Giridhar E-mail: aloksharan@email.com; Allam, Srinivasa Rao E-mail: aloksharan@email.com; Satyanarayana, S. V. M. E-mail: aloksharan@email.com; Sharan, Alok E-mail: aloksharan@email.com

    2014-10-15

    We present the study of the optical diffraction pattern of one and two-dimensional gratings with defects, designed using desktop pc and printed on OHP sheet using laser printer. Gratings so prepared, using novel low cost technique provides good visual aid in teaching. Diffraction pattern of the monochromatic light (632.8nm) from the grating so designed is similar to that of x-ray diffraction pattern of crystal lattice with point defects in one and two-dimensions. Here both optical and x-ray diffractions are Fraunhofer. The information about the crystalline lattice structure and the defect size can be known.

  16. Higgs boson at LHC: a diffractive opportunity

    SciTech Connect

    Ducati, M. B. Gay; Silveira, G. G.

    2009-03-23

    An alternative process is presented for diffractive Higgs boson production in peripheral pp collisions, where the particles interact through the Double Pomeron Exchange. The event rate is computed as a central-rapidity distribution for Tevatron and LHC energies leading to a result around 0.6 pb, higher than the predictions from previous approaches. Therefore, this result arises as an enhanced signal for the detection of the Higgs boson in hadron colliders. The predictions for the Higgs boson photoproduction are compared to the ones obtained from a similar approach proposed by the Durham group, enabling an analysis of the future developments of its application to pp and AA collisions.

  17. Multiwavelength Anomalous Diffraction at High X-Ray Intensity

    NASA Astrophysics Data System (ADS)

    Son, Sang-Kil; Chapman, Henry N.; Santra, Robin

    2011-11-01

    The multiwavelength anomalous diffraction (MAD) method is used to determine phase information in x-ray crystallography by employing anomalous scattering from heavy atoms. X-ray free-electron lasers (FELs) show promise for revealing the structure of single molecules or nanocrystals, but the phase problem remains largely unsolved. Because of the ultrabrightness of x-ray FEL, samples experience severe electronic radiation damage, especially to heavy atoms, which hinders direct implementation of MAD with x-ray FELs. Here, we propose a generalized version of MAD phasing at high x-ray intensity. We demonstrate the existence of a Karle-Hendrickson-type equation in the high-intensity regime and calculate relevant coefficients with detailed electronic damage dynamics of heavy atoms. The present method offers a potential for ab initio structural determination in femtosecond x-ray nanocrystallography.

  18. Multiwavelength anomalous diffraction at high x-ray intensity.

    PubMed

    Son, Sang-Kil; Chapman, Henry N; Santra, Robin

    2011-11-18

    The multiwavelength anomalous diffraction (MAD) method is used to determine phase information in x-ray crystallography by employing anomalous scattering from heavy atoms. X-ray free-electron lasers (FELs) show promise for revealing the structure of single molecules or nanocrystals, but the phase problem remains largely unsolved. Because of the ultrabrightness of x-ray FEL, samples experience severe electronic radiation damage, especially to heavy atoms, which hinders direct implementation of MAD with x-ray FELs. Here, we propose a generalized version of MAD phasing at high x-ray intensity. We demonstrate the existence of a Karle-Hendrickson-type equation in the high-intensity regime and calculate relevant coefficients with detailed electronic damage dynamics of heavy atoms. The present method offers a potential for ab initio structural determination in femtosecond x-ray nanocrystallography.

  19. Tolerance analysis on diffraction efficiency and polychromatic integral diffraction efficiency for harmonic diffractive optics

    NASA Astrophysics Data System (ADS)

    Shan, Mao

    2016-10-01

    In this dissertation, the mathematical model of effect of manufacturing errors including microstructure relative height error and relative width error on diffraction efficiency for the harmonic diffractive optical elements (HDEs) is set up. According to the expression of the phase delay and diffraction efficiency of the HDEs, the expression of diffraction efficiency of refraction and diffractive optical element with the microstructure height and periodic width errors in fabrication process is presented in this paper. Furthermore, the effect of manufacturing errors on diffraction efficiency for the harmonic diffractive optical elements is studied, and diffraction efficiency change is analyzed as the relative microstructure height-error in the same and in the opposite sign as well as relative width-error in the same and in the opposite sign. Example including infrared wavelength with materials GE has been discussed in this paper. Two kinds of manufacturing errors applied in 3.7 4.3um middle infrared and 8.7-11.5um far infrared optical system which results in diffraction efficiency and PIDE of HDEs are studied. The analysis results can be used for manufacturing error control in micro-structure height and periodic width. Results can be used for HDEs processing.

  20. Inelastic diffraction at the LHC

    NASA Astrophysics Data System (ADS)

    Troshin, S. M.; Tyurin, N. E.

    2017-03-01

    The relativistic scattering was one of the scientific fields where Academician V.G. Kadyshevsky has made an important and highly cited contribution [1]. In this paper we discuss the high-energy dependencies of diffractive and non-diffractive inelastic cross-sections in view of the recent LHC data which reveal a presence of the reflective scattering mode.

  1. Computer Simulation of Diffraction Patterns.

    ERIC Educational Resources Information Center

    Dodd, N. A.

    1983-01-01

    Describes an Apple computer program (listing available from author) which simulates Fraunhofer and Fresnel diffraction using vector addition techniques (vector chaining) and allows user to experiment with different shaped multiple apertures. Graphics output include vector resultants, phase difference, diffraction patterns, and the Cornu spiral…

  2. Ptychographic Fresnel coherent diffractive imaging

    SciTech Connect

    Vine, D. J.; Williams, G. J.; Nugent, K. A.; Abbey, B.; Pfeifer, M. A.; Clark, J. N.; Peele, A. G.; Jonge, M. D. de; McNulty, I.

    2009-12-15

    This paper reports improved reconstruction of complex wave fields from extended objects. The combination of ptychography with Fresnel diffractive imaging results in better reconstructions with fewer iterations required to convergence than either method considered separately. The method is applied to retrieve the projected thickness of a gold microstructure and comparative results using ptychography and Fresnel diffractive imaging are presented.

  3. Application of the Covariant Spectator Theory to the Study of Heavy and Heavy-Light Mesons

    NASA Astrophysics Data System (ADS)

    Leitão, Sofia; Stadler, Alfred; Peña, M. T.; Biernat, Elmar P.

    2017-03-01

    As an application of the Covariant Spectator Theory (CST) we calculate the spectrum of heavy-light and heavy-heavy mesons using covariant versions of a linear confining potential, a one-gluon exchange, and a constant interaction. The CST equations possess the correct one-body limit and are therefore well-suited to describe mesons in which one quark is much heavier than the other. We find a good fit to the mass spectrum of heavy-light and heavy-heavy mesons with just three parameters (apart from the quark masses). Remarkably, the fit parameters are nearly unchanged when we fit to experimental pseudoscalar states only or to the whole spectrum. Because pseudoscalar states are insensitive to spin-orbit interactions and do not determine spin-spin interactions separately from central interactions, this result suggests that it is the covariance of the kernel that correctly predicts the spin-dependent quark-antiquark interactions.

  4. Heavy Rescue - Course Outline.

    DTIC Science & Technology

    1980-11-01

    used during heavy rescue operations . Methods and procedures for utilizing heavy rescue equipment. 4 Methods of developing improvised rescue equipment...utilizing available materials. A simulated exercise utilizing various rescue operations and techniques. Methods and procedures for the maintenance and...HEAVY RESCUE CONSIDERATIONS LEVEL I PERFORMANCE GOALS: 1 Hour GIVEN: 1. Summary of blocked access considerations during heavy rescue operations 2

  5. Lamb wave diffraction tomography

    NASA Astrophysics Data System (ADS)

    Malyarenko, Eugene Valentinovich

    , fails. Diffraction tomography is a way to incorporate scattering effects into tomographic algorithms in order to improve image quality and resolution. This work describes the iterative reconstruction procedure developed for the Lamb Wave tomography and allowing for ray bending correction for imaging of moderately scattering objects.

  6. Heavy-ion radiotherapy

    NASA Astrophysics Data System (ADS)

    Kanai, Tatsuaki

    2000-11-01

    Heavy-ion radiotherapy using high-energy carbon beams has been performed at the National Institute of Radiological Sciences, Japan. The physical frame works for heavy-ion radiotherapy are established using physical understandings of radiation physics. In order to increase the accuracy of heavy-ion radiotherapy, many physical problems should be solved. Unsolved problems, such as the depth dose distributions, range of heavy-ion in patients and heavy-ion dosimetry in the radiation therapy, are discussed. .

  7. Optical diffraction properties of multimicrogratings

    SciTech Connect

    Rothenbach, Christian A.; Kravchenko, Ivan I.; Gupta, Mool C.

    2015-02-27

    This paper shows the results of optical diffraction properties of multimicrograting structures fabricated by e-beam lithography. Multimicrograting consist of arrays of hexagonally shaped cells containing periodic one-dimensional (1D) grating lines in different orientations and arrayed to form large area patterns. We analyzed the optical diffraction properties of multimicrogratings by studying the individual effects of the several periodic elements of multimicrogratings. The observed optical diffraction pattern is shown to be the combined effect of the periodic and non-periodic elements that define the multimicrogratings and the interaction between different elements. We measured the total transverse electric (TE) diffraction efficiency of multimicrogratings and found it to be 32.1%, which is closely related to the diffraction efficiency of 1D periodic grating lines of the same characteristics, measured to be 33.7%. Beam profiles of the optical diffraction patterns from multimicrogratings are captured with a CCD sensor technique. Interference fringes were observed under certain conditions formed by multimicrograting beams interfering with each other. Finally, these diffraction structures may find applications in sensing, nanometrology, and optical interconnects.

  8. Optical diffraction properties of multimicrogratings

    DOE PAGES

    Rothenbach, Christian A.; Kravchenko, Ivan I.; Gupta, Mool C.

    2015-02-27

    This paper shows the results of optical diffraction properties of multimicrograting structures fabricated by e-beam lithography. Multimicrograting consist of arrays of hexagonally shaped cells containing periodic one-dimensional (1D) grating lines in different orientations and arrayed to form large area patterns. We analyzed the optical diffraction properties of multimicrogratings by studying the individual effects of the several periodic elements of multimicrogratings. The observed optical diffraction pattern is shown to be the combined effect of the periodic and non-periodic elements that define the multimicrogratings and the interaction between different elements. We measured the total transverse electric (TE) diffraction efficiency of multimicrogratings andmore » found it to be 32.1%, which is closely related to the diffraction efficiency of 1D periodic grating lines of the same characteristics, measured to be 33.7%. Beam profiles of the optical diffraction patterns from multimicrogratings are captured with a CCD sensor technique. Interference fringes were observed under certain conditions formed by multimicrograting beams interfering with each other. Finally, these diffraction structures may find applications in sensing, nanometrology, and optical interconnects.« less

  9. Arbitrary shape surface Fresnel diffraction.

    PubMed

    Shimobaba, Tomoyoshi; Masuda, Nobuyuki; Ito, Tomoyoshi

    2012-04-09

    Fresnel diffraction calculation on an arbitrary shape surface is proposed. This method is capable of calculating Fresnel diffraction from a source surface with an arbitrary shape to a planar destination surface. Although such calculation can be readily calculated by the direct integral of a diffraction calculation, the calculation cost is proportional to O(N²) in one dimensional or O(N⁴) in two dimensional cases, where N is the number of sampling points. However, the calculation cost of the proposed method is O(N log N) in one dimensional or O(N² log N) in two dimensional cases using non-uniform fast Fourier transform.

  10. Diffractive optics in adverse environments

    NASA Technical Reports Server (NTRS)

    Behrmann, Gregory P.

    1993-01-01

    An investigation at the Army Research Laboratory is in progress to characterize DOE performance in mil-spec environments. One of the most significant environmental influences is temperature. An analysis of a diffractive lens is presented in which optical performance is described as a function of temperature. In particular, we review the thermal dependence of focal length and diffraction efficiency. It is shown that the change in these parameters is independent of lens shape and relates only to material properties. Thermalized hybrid refractive/diffractive designs are discussed.

  11. Diffraction dissociation at the LHC

    SciTech Connect

    Jenkovszky, Laszlo; Orava, Risto; Salii, Andrii

    2013-04-15

    We report on recent calculations of low missing mass single (SD) and double (DD) diffractive dissociation at LHC energies. The calculations are based on a dual-Regge model, dominated by a single Pomeron exchange. The diffractively excited states lie on the nucleon trajectory N*, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single-and double diffraction dissociation in the kinematical range of present and future LHC measurements are given.

  12. Diffractive Higgs boson photoproduction in {gamma}p process

    SciTech Connect

    Ducati, M. B. Gay; Silveira, G. G.

    2008-12-01

    We explore an alternative process for diffractive Higgs boson production in peripheral pp collisions arising from double Pomeron exchange in photon-proton interaction. We introduce the impact factor formalism in order to enable the gluon ladder exchange in the photon-proton subprocess, and to permit central Higgs production. The event rate for diffractive Higgs production in central rapidity is estimated to be about 0.6 pb at Tevatron and LHC energies. This result is higher than predictions from other approaches of diffractive Higgs production, showing that the alternative production process leads to an enhanced signal for the detection of the Higgs boson at hadron colliders. Our results are compared with those obtained from a similar approach proposed by the Durham Group. In this way, we may examine future developments in its application to pp and AA collisions.

  13. Measurement of neutron diffraction with compact neutron source RANS

    NASA Astrophysics Data System (ADS)

    Ikeda, Y.; Takamura, M.; Taketani, A.; Sunaga, H.; Otake, Y.; Suzuki, H.; Kumagai, M.; Oba, Y.; Hama, T.

    2016-11-01

    Diffraction is used as a measurement technique for crystal structure. X-rays or electron beam with wavelength that is close to the lattice constant of the crystal is often used for the measurement. They have sensitivity in surface (0.01mm) of heavy metals due to the mean free path for heavy ions. Neutron diffraction has the probe of the internal structure of the heavy metals because it has a longer mean free path than that of the X-rays or the electrons. However, the neutron diffraction measurement is not widely used because large facilities are required in the many neutron sources. RANS (Riken Accelerator-driven Compact Neutron Source) is developed as a neutron source which is usable easily in laboratories and factories. In RANS, fast neutrons are generated by 7MeV protons colliding on a Be target. Some fast neutrons are moderated with polyethylene to thermal neutrons. The thermal neutrons of 10meV which have wavelength of 10nm can be used for the diffraction measurement. In this study, the texture evolution in steels was measured with RANS and the validity of the compact neutron source was proved. The texture of IF steel sheets with the thickness of 1.0mm was measured with 10minutes run. The resolution is 2% and is enough to analyze a evolution in texture due to compression/tensile deformation or a volume fraction of two phases in the steel sample. These results have proven the possibility to use compact neutron source for the analysis of mesoscopic structure of metallic materials.

  14. Spatiotemporal optical pulse transformation by a resonant diffraction grating

    SciTech Connect

    Golovastikov, N. V.; Bykov, D. A. Doskolovich, L. L. Soifer, V. A.

    2015-11-15

    The diffraction of a spatiotemporal optical pulse by a resonant diffraction grating is considered. The pulse diffraction is described in terms of the signal (the spatiotemporal incident pulse envelope) passage through a linear system. An analytic approximation in the form of a rational function of two variables corresponding to the angular and spatial frequencies has been obtained for the transfer function of the system. A hyperbolic partial differential equation describing the general form of the incident pulse envelope transformation upon diffraction by a resonant diffraction grating has been derived from the transfer function. A solution of this equation has been obtained for the case of normal incidence of a pulse with a central frequency lying near the guided-mode resonance of a diffraction structure. The presented results of numerical simulations of pulse diffraction by a resonant grating show profound changes in the pulse envelope shape that closely correspond to the proposed theoretical description. The results of the paper can be applied in creating new devices for optical pulse shape transformation, in optical information processing problems, and analog optical computations.

  15. Electrically-programmable diffraction grating

    DOEpatents

    Ricco, A.J.; Butler, M.A.; Sinclair, M.B.; Senturia, S.D.

    1998-05-26

    An electrically-programmable diffraction grating is disclosed. The programmable grating includes a substrate having a plurality of electrodes formed thereon and a moveable grating element above each of the electrodes. The grating elements are electrostatically programmable to form a diffraction grating for diffracting an incident beam of light as it is reflected from the upper surfaces of the grating elements. The programmable diffraction grating, formed by a micromachining process, has applications for optical information processing (e.g. optical correlators and computers), for multiplexing and demultiplexing a plurality of light beams of different wavelengths (e.g. for optical fiber communications), and for forming spectrometers (e.g. correlation and scanning spectrometers). 14 figs.

  16. Femtosecond single-electron diffraction

    PubMed Central

    Lahme, S.; Kealhofer, C.; Krausz, F.; Baum, P.

    2014-01-01

    Ultrafast electron diffraction allows the tracking of atomic motion in real time, but space charge effects within dense electron packets are a problem for temporal resolution. Here, we report on time-resolved pump-probe diffraction using femtosecond single-electron pulses that are free from intra-pulse Coulomb interactions over the entire trajectory from the source to the detector. Sufficient average electron current is achieved at repetition rates of hundreds of kHz. Thermal load on the sample is avoided by minimizing the pump-probe area and by maximizing heat diffusion. Time-resolved diffraction from fibrous graphite polycrystals reveals coherent acoustic phonons in a nanometer-thick grain ensemble with a signal-to-noise level comparable to conventional multi-electron experiments. These results demonstrate the feasibility of pump-probe diffraction in the single-electron regime, where simulations indicate compressibility of the pulses down to few-femtosecond and attosecond duration. PMID:26798778

  17. X-Ray Diffraction Apparatus

    NASA Technical Reports Server (NTRS)

    Blake, David F. (Inventor); Bryson, Charles (Inventor); Freund, Friedmann (Inventor)

    1996-01-01

    An x-ray diffraction apparatus for use in analyzing the x-ray diffraction pattern of a sample is introduced. The apparatus includes a beam source for generating a collimated x-ray beam having one or more discrete x-ray energies, a holder for holding the sample to be analyzed in the path of the beam, and a charge-coupled device having an array of pixels for detecting, in one or more selected photon energy ranges, x-ray diffraction photons produced by irradiating such a sample with said beam. The CCD is coupled to an output unit which receives input information relating to the energies of photons striking each pixel in the CCD, and constructs the diffraction pattern of photons within a selected energy range striking the CCD.

  18. Multiple annular linear diffractive axicons.

    PubMed

    Bialic, Emilie; de la Tocnaye, Jean-Louis de Bougrenet

    2011-04-01

    We propose a chromatic analysis of multiple annular linear diffractive axicons. Large aperture axicons are optical devices providing achromatic nondiffracting beams, with an extended depth of focus, when illuminated by a white light source, due to chromatic foci superimposition. Annular apertures introduce chromatic foci separation, and because chromatic aberrations result in focal segment axial shifts, polychromatic imaging properties are partially lost. We investigate here various design parameters that can be used to achieve color splitting, filtering, and combining using these properties. In order to improve the low-power efficiency of a single annular axicon, we suggest a spatial multiplexing of concentric annular axicons with different sizes and periods we call multiple annular aperture diffractive axicons (MALDAs). These are chosen to maintain focal depths while enabling color imaging with sufficient diffraction efficiency. Illustrations are given for binary phase diffractive axicons, considering technical aspects such as grating design wavelength and phase dependence due to the grating thickness.

  19. Fresnel diffraction by spherical obstacles

    NASA Technical Reports Server (NTRS)

    Hovenac, Edward A.

    1989-01-01

    Lommel functions were used to solve the Fresnel-Kirchhoff diffraction integral for the case of a spherical obstacle. Comparisons were made between Fresnel diffraction theory and Mie scattering theory. Fresnel theory is then compared to experimental data. Experiment and theory typically deviated from one another by less than 10 percent. A unique experimental setup using mercury spheres suspended in a viscous fluid significantly reduced optical noise. The major source of error was due to the Gaussian-shaped laser beam.

  20. Centrality dependence of identified particle elliptic flow in relativistic heavy ion collisions at sNN=7.762.4 GeV

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Chisman, O.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, H. Z.; Huang, B.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, Y.; Li, W.; Li, C.; Li, X.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, Y. G.; Ma, G. L.; Ma, R.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X.; Sun, Z.; Sun, Y.; Sun, X. M.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, Y.; Wang, G.; Wang, Y.; Wang, J. S.; Wang, H.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Z.; Xu, H.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I. -K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Y.; Zhang, S.; Zhang, J.; Zhang, J.; Zhang, Z.; Zhang, X. P.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2016-01-19

    Here, elliptic flow (v2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √sNN = 7.7–62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √sNN = 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v2 for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.

  1. Analysis of spatial autocorrelation patterns of heavy and super-heavy rainfall in Iran

    NASA Astrophysics Data System (ADS)

    Rousta, Iman; Doostkamian, Mehdi; Haghighi, Esmaeil; Ghafarian Malamiri, Hamid Reza; Yarahmadi, Parvane

    2017-09-01

    Rainfall is a highly variable climatic element, and rainfall-related changes occur in spatial and temporal dimensions within a regional climate. The purpose of this study is to investigate the spatial autocorrelation changes of Iran's heavy and super-heavy rainfall over the past 40 years. For this purpose, the daily rainfall data of 664 meteorological stations between 1971 and 2011 are used. To analyze the changes in rainfall within a decade, geostatistical techniques like spatial autocorrelation analysis of hot spots, based on the Getis-Ord G i statistic, are employed. Furthermore, programming features in MATLAB, Surfer, and GIS are used. The results indicate that the Caspian coast, the northwest and west of the western foothills of the Zagros Mountains of Iran, the inner regions of Iran, and southern parts of Southeast and Northeast Iran, have the highest likelihood of heavy and super-heavy rainfall. The spatial pattern of heavy rainfall shows that, despite its oscillation in different periods, the maximum positive spatial autocorrelation pattern of heavy rainfall includes areas of the west, northwest and west coast of the Caspian Sea. On the other hand, a negative spatial autocorrelation pattern of heavy rainfall is observed in central Iran and parts of the east, particularly in Zabul. Finally, it is found that patterns of super-heavy rainfall are similar to those of heavy rainfall.

  2. Diffraction efficiency analysis for multi-level diffractive optical elements

    SciTech Connect

    Erteza, I.A.

    1995-11-01

    Passive optical components can be broken down into two main groups: Refractive elements and diffractive elements. With recent advances in manufacturing technologies, diffractive optical elements are becoming increasingly more prevalent in optical systems. It is therefore important to be able to understand and model the behavior of these elements. In this report, we present a thorough analysis of a completely general diffractive optical element (DOE). The main goal of the analysis is to understand the diffraction efficiency and power distribution of the various modes affected by the DOE. This is critical to understanding cross talk and power issues when these elements are used in actual systems. As mentioned, the model is based on a completely general scenario for a DOE. This allows the user to specify the details to model a wide variety of diffractive elements. The analysis is implemented straightforwardly in Mathematica. This report includes the development of the analysis, the Mathematica implementation of the model and several examples using the Mathematical analysis tool. It is intended that this tool be a building block for more specialized analyses.

  3. Electromagnetic diffraction efficiencies for plane reflection diffraction gratings

    NASA Technical Reports Server (NTRS)

    Marathay, A. S.; Shrode, T. E.

    1974-01-01

    The theory and computer programs, based on electromagnetic theory, for the analysis and design of echelle gratings were developed. The gratings are designed for instruments that operate in the ultraviolet portion of the spectrum. The theory was developed so that the resulting computer programs will be able to analyze deep (up to 30 wavelengths) gratings by including as many as 100 real or homogeneous diffraction orders. The program calculates the complex amplitude coefficient for each of the diffracted orders. A check on the numerical method used to solve the integral equations is provided by a conservation of energy calculation.

  4. 6. Detail of heavy timber structural system at ground floor ...

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

    6. Detail of heavy timber structural system at ground floor level of Tender Frame Shop. - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Tender Frame Shop, Bounded by West Broad, Jones, West Boundary & Hull Streets, Savannah, Chatham County, GA

  5. Imaging the proton via hard exclusive production in diffractive pp scattering

    SciTech Connect

    Charles Hyde; Leonid Frankfurt; Mark Strikman; Christian Weiss

    2007-05-21

    We discuss the prospects for probing Generalized Parton Distributions (GPDs) via exclusive production of a high-mass system (H = heavy quarkonium, di-photon, di-jet, Higgs boson) in diffractive pp scattering, pp -> p + H + p. In such processes the interplay of hard and soft interactions gives rise to a diffraction pattern in the final-state proton transverse momenta, which is sensitive to the transverse spatial distribution of partons in the colliding protons. We comment on the plans for diffractive pp measurements at RHIC and LHC. Such studies could complement future measurements of GPDs in hard exclusive ep scattering (JLab, COMPASS, EIC).

  6. Holographic double diffraction of Higgs and the AdS/CFT graviton/Pomeron

    NASA Astrophysics Data System (ADS)

    Brower, Richard; Djuric, Marko; Tan, Chung-I.

    2014-11-01

    The holographic approach to double diffractive Higgs production is presented in terms of exchanging the AdS graviton/Pomeron. The goal is to provide a simple framework for central exclusive production from a dual strong coupling perspective.

  7. Single Photon diffraction and interference

    NASA Astrophysics Data System (ADS)

    Hodge, John

    2015-04-01

    A previous paper based on the Scalar Theory of Everything studied photon diffraction and interference (IntellectualArchive, Vol.1, No. 3, P. 20, Toronto, Canada July 2012. http://intellectualarchive.com/?link=item&id=597). Several photons were required in the experiment at the same time. Interference experiments with one photon in the experiment at a time also showed interference patterns. The previous paper with the Bohm Interpretation, models of the screen and mask, and the Transaction Interpretation of Quantum Mechanics were combined. The reverse wave required by the Transaction Interpretation was provided by a reflected plenum wave rather than a reverse time wave. The speed of the plenum wave was assumed to be much faster than the speed of photons/light. Using the assumptions of Fraunhofer diffraction resulted in the same equation for the photon distribution on a screen as the intensity pattern of the Fraunhofer diffraction. (http://myplace.frontier.com/ ~ jchodge/)

  8. Electron diffraction by plasmon waves

    NASA Astrophysics Data System (ADS)

    García de Abajo, F. J.; Barwick, B.; Carbone, F.

    2016-07-01

    An electron beam traversing a structured plasmonic field is shown to undergo diffraction with characteristic angular patterns of both elastic and inelastic outgoing electron components. In particular, a plasmonic grating (e.g., a standing wave formed by two counterpropagating plasmons in a thin film) produces diffraction orders of the same parity as the net number of exchanged plasmons. Large diffracted beam fractions are predicted to occur for realistic plasmon intensities in attainable geometries due to a combination of phase and amplitude changes locally imprinted on the passing electron wave. Our study opens vistas in the study of multiphoton exchanges between electron beams and evanescent optical fields with unexplored effects related to the transversal component of the electron wave function.

  9. Diffractive digital lensless holographic microscopy with fine spectral tuning.

    PubMed

    Mendoza-Yero, Omel; Tajahuerce, Enrique; Lancis, Jesús; Garcia-Sucerquia, Jorge

    2013-06-15

    We experimentally demonstrate an all-diffractive optical setup for digital lensless holographic microscopy with easy wavelength line selection and micrometric resolution. In the proposed system, an ultrashort laser pulse is focused with a diffractive lens (DL) onto a pinhole of diameter close to its central wavelength to achieve a highly spatially coherent illumination cone as well as a spectral line with narrow width. To scan the complete spectrum of the light source the DL is displaced with respect to the pinhole plane. The proposed microscopy setup allows us to spectrally separate contributions from different sections of a sample, which may be attractive for several applications in life sciences.

  10. Boundary diffraction wave integrals for diffraction modeling of external occulters.

    PubMed

    Cady, Eric

    2012-07-02

    An occulter is a large diffracting screen which may be flown in conjunction with a telescope to image extrasolar planets. The edge is shaped to minimize the diffracted light in a region beyond the occulter, and a telescope may be placed in this dark shadow to view an extrasolar system with the starlight removed. Errors in position, orientation, and shape of the occulter will diffract additional light into this region, and a challenge of modeling an occulter system is to accurately and quickly model these effects. We present a fast method for the calculation of electric fields following an occulter, based on the concept of the boundary diffraction wave: the 2D structure of the occulter is reduced to a 1D edge integral which directly incorporates the occulter shape, and which can be easily adjusted to include changes in occulter position and shape, as well as the effects of sources-such as exoplanets-which arrive off-axis to the occulter. The structure of a typical implementation of the algorithm is included.

  11. Diffraction-induced coherence levels.

    PubMed

    Tavrov, Alexander; Schmit, Joanna; Kerwien, Norbert; Osten, Wolfgang; Tiziani, Hans

    2005-04-10

    We examined the influence of complex diffraction effects on low-coherence fringes created for high-aspect depth-to-width ratio structures called trenches. The coherence function was analyzed for these micrometer-wide trenches and was registered with a white-light interference microscope. For some types of surface structure we observed that additional low-coherence fringes that do not correspond directly to the surface topology are formed near the sharp edges of the structures. These additional coherence fringes were studied by rigorous numerical evaluations of vector diffractions, and these simulated interference fields were then compared with experimental results that were obtained with a white-light interference microscope.

  12. Diffraction encoded position measuring apparatus

    DOEpatents

    Tansey, Richard J.

    1991-01-01

    When a lightwave passes through a transmission grating, diffracted beams appear at the output or opposite side of the grating that are effectively Doppler shifted in frequency (phase) whereby a detector system can compare the phase of the zero order and higher order beams to obtain an indication of position. Multiple passes through the grating increase resolution for a given wavelength of a laser signal. The resolution can be improved further by using a smaller wavelength laser to generate the grating itself. Since the grating must only have a pitch sufficient to produce diffracted orders, inexpensive, ultraviolet wavelength lasers can be utilized and still obtain high resolution detection.

  13. Diffraction encoded position measuring apparatus

    DOEpatents

    Tansey, R.J.

    1991-09-24

    When a lightwave passes through a transmission grating, diffracted beams appear at the output or opposite side of the grating that are effectively Doppler shifted in frequency (phase) whereby a detector system can compare the phase of the zero order and higher order beams to obtain an indication of position. Multiple passes through the grating increase resolution for a given wavelength of a laser signal. The resolution can be improved further by using a smaller wavelength laser to generate the grating itself. Since the grating must only have a pitch sufficient to produce diffracted orders, inexpensive, ultraviolet wavelength lasers can be utilized and still obtain high resolution detection. 3 figures.

  14. High-pressure neutron diffraction

    SciTech Connect

    Xu, Hongwu

    2011-01-10

    This lecture will cover progress and prospect of applications of high-pressure neutron diffraction techniques to Earth and materials sciences. I will first introduce general high-pressure research topics and available in-situ high-pressure techniques. Then I'll talk about high-pressure neutron diffraction techniques using two types of pressure cells: fluid-driven and anvil-type cells. Lastly, I will give several case studies using these techniques, particularly, those on hydrogen-bearing materials and magnetic transitions.

  15. Intramolecular photoelectron diffraction in the gas phase

    NASA Astrophysics Data System (ADS)

    Ueda, K.; Miron, C.; Plésiat, E.; Argenti, L.; Patanen, M.; Kooser, K.; Ayuso, D.; Mondal, S.; Kimura, M.; Sakai, K.; Travnikova, O.; Palacios, A.; Decleva, P.; Kukk, E.; Martín, F.

    2013-09-01

    We report unambiguous experimental and theoretical evidence of intramolecular photoelectron diffraction in the collective vibrational excitation that accompanies high-energy photoionization of gas-phase CF4, BF3, and CH4 from the 1s orbital of the central atom. We show that the ratios between vibrationally resolved photoionization cross sections (v-ratios) exhibit pronounced oscillations as a function of photon energy, which is the fingerprint of electron diffraction by the surrounding atomic centers. This interpretation is supported by the excellent agreement between first-principles static-exchange and time-dependent density functional theory calculations and high resolution measurements, as well as by qualitative agreement at high energies with a model in which atomic displacements are treated to first order of perturbation theory. The latter model allows us to rationalize the results for all the v-ratios in terms of a generalized v-ratio, which contains information on the structure of the above three molecules and the corresponding molecular cations. A fit of the measured v-ratios to a simple formula based on this model suggests that the method could be used to obtain structural information of both neutral and ionic molecular species.

  16. Intramolecular photoelectron diffraction in the gas phase.

    PubMed

    Ueda, K; Miron, C; Plésiat, E; Argenti, L; Patanen, M; Kooser, K; Ayuso, D; Mondal, S; Kimura, M; Sakai, K; Travnikova, O; Palacios, A; Decleva, P; Kukk, E; Martín, F

    2013-09-28

    We report unambiguous experimental and theoretical evidence of intramolecular photoelectron diffraction in the collective vibrational excitation that accompanies high-energy photoionization of gas-phase CF4, BF3, and CH4 from the 1s orbital of the central atom. We show that the ratios between vibrationally resolved photoionization cross sections (v-ratios) exhibit pronounced oscillations as a function of photon energy, which is the fingerprint of electron diffraction by the surrounding atomic centers. This interpretation is supported by the excellent agreement between first-principles static-exchange and time-dependent density functional theory calculations and high resolution measurements, as well as by qualitative agreement at high energies with a model in which atomic displacements are treated to first order of perturbation theory. The latter model allows us to rationalize the results for all the v-ratios in terms of a generalized v-ratio, which contains information on the structure of the above three molecules and the corresponding molecular cations. A fit of the measured v-ratios to a simple formula based on this model suggests that the method could be used to obtain structural information of both neutral and ionic molecular species.

  17. Diffractive Z boson pair production at the LHC in the large extra dimensions scenario

    NASA Astrophysics Data System (ADS)

    Gonçalves, V. P.; Sauter, W. K.; Thiel, M.

    2014-04-01

    In this paper we study the diffractive Z boson pair production mediated by the Kaluza-Klein graviton in the large extra dimensions scenario at the CERN Large Hadron Collider energies. Considering the Durham model, we estimate the total cross section for the central inclusive and exclusive diffractive production of a Z boson pair in pp/pPb/PbPb collisions. Our results indicate that the experimental analysis of the central inclusive production in pp collisions is feasible at the CERN LHC.

  18. Phase retrieval from single biomolecule diffraction pattern.

    PubMed

    Ikeda, Shiro; Kono, Hidetoshi

    2012-02-13

    In this paper, we propose the SPR (sparse phase retrieval) method, which is a new phase retrieval method for coherent x-ray diffraction imaging (CXDI). Conventional phase retrieval methods effectively solve the problem for high signal-to-noise ratio measurements, but would not be sufficient for single biomolecular imaging which is expected to be realized with femto-second x-ray free electron laser pulses. The SPR method is based on the Bayesian statistics. It does not need to set the object boundary constraint that is required by the commonly used hybrid input-output (HIO) method, instead a prior distribution is defined with an exponential distribution and used for the estimation. Simulation results demonstrate that the proposed method reconstructs the electron density under a noisy condition even some central pixels are masked.

  19. Location of platinum binding sites on bacteriorhodopsin by electron diffraction

    SciTech Connect

    Dumont, M.E.; Wiggins, J.W.; Hayward, S.B.

    1981-05-01

    A platinum-containing derivative of bacteriorhodopsin has been prepared by treating purple membranes with glycyl-L-methionatoplatinum. Low-dose electron diffraction was used to identify Pt binding sites in the 5.6 A resolution reconstruction of the bacteriorhodopsin unit cell in projection. This is a necessary first step in the use of the Pt derivative for identifying the parts of the amino acid sequence corresponding to the ..cap alpha.. helices in the bacteriorhodopsin structure and for obtaining phases for reflections out to 3.5 A resolution by the method of heavy-atom isomorphous replacement. The largest peak in a Fourier difference map between platinum-labeled and native purple membrane is larger than thespurious features expected to arise from errors in measurements of diffraction intensities.

  20. Resonant scattering and diffraction beamline P09 at PETRA III.

    PubMed

    Strempfer, J; Francoual, S; Reuther, D; Shukla, D K; Skaugen, A; Schulte-Schrepping, H; Kracht, T; Franz, H

    2013-07-01

    The resonant scattering and diffraction beamline P09 at PETRA III is designed for X-ray experiments requiring small beams, energy tunability, variable polarization and high photon flux. It is highly flexible in terms of beam size and offers full higher harmonic suppression. A state-of-the-art double phase-retarder set-up provides variable linear or circular polarization. A high-precision Psi-diffractometer and a heavy-load diffractometer in horizontal Psi-geometry allow the accommodation of a wide variety of sample environments. A 14 T cryo-magnet is available for scattering experiments in magnetic fields.

  1. Small angle detectors for study diffractive processes with CMS

    NASA Astrophysics Data System (ADS)

    Albrow, M.; Bell, A. J.; Enterria, D. d.; Hall-Wilton, R.; Los, S.; Mokhov, N.; Murray, M.; Penzo, A.; Popescu, S.; Ronzhin, A.; Samoylenko, V. D.; Sobol, A.; Veres, G.

    2014-10-01

    The approach and detectors for diffractive physics based on two current projects—Forward Shower Counter (FSC) and Proton Precision Spectrometer (PPS) are presented. FSC system consists of six (3+3) Stations of scintillator counters, which surround closely the beam pipes along 59 m < |z| < 140 m from IP5 on both plus (+) and minus (-) sides. These will detect showers from very forward particles with rapidity 7.5 < |η| < 10 interacting in the beam pipe and surrounding material. FSC allow measurements of single diffraction: p+p → p+G+X (where G is rapidity gap) for lower masses and double diffraction p+p → X+G+X with a large central rapidity gap. The counters can also be used for beam real-time monitoring and will make an invaluable contribution to the understanding of the background environment and its topology. PPS is designed for study the central exclusive production pp → p+X+p, where the + signs denote the absence of hadronic activity (that is, the presence of a rapidity gap) between the outgoing protons and the decay products of the central system X. The precise measurement of the kinematical parameters of the outgoing protons enables to study the properties of the central state X. In PPS part we consider the detector for high precision timing of these protons—QUARTIC. It consists of L-shape bars with quartz or sapphire radiator. The time resolution of the QUARTIC prototypes achieved ≈ 10 ps.

  2. Neutron diffraction studies of bacteriorhodopsin

    SciTech Connect

    Trewhella, J.; Popot, J.L.; Engelman, D.M.; Zaccai, G.

    1985-01-01

    Neutron diffraction studies of bacteriorhodopsin have utilized the entire range of deuterium labeling techniques that are commonly used in biological neutron scattering experiments. We will review the work published in this area and report on current projects. 10 refs., 1 fig.

  3. Diffraction Plates for Classroom Demonstrations

    ERIC Educational Resources Information Center

    Hoover, Richard B.

    1969-01-01

    Describes the computer generation of random and regular arrays of apertures on photographic film and their applications for classroom demonstrations of the Fraunhofer patterns produced by simple and complex apertures, Babinet's principle, resolution according to the Rayleigh criterion, and many other aspects of diffraction. (LC)

  4. Fresnel Diffraction for CTR Microbunching

    SciTech Connect

    Tikhoplav, R.; Knyazik, A.; Rosenzweig, J. B.; Andonian, G.

    2009-01-22

    Laser beams of high intensities are routinely used for IFEL experiments. Such beams can potentially destroy microbunching diagnostic tools such as coherent transition radiation foils due to their low damage thresholds. Near-field Fresnel diffraction scheme for termination of CO{sub 2} laser beam has been experimentally studied and is presented in this paper. Novel THz camera was utilized for such study.

  5. Hard diffraction and rapidity gaps

    SciTech Connect

    Albrow, M.G.

    1994-08-01

    I describe the evolution of experiments at hadron colliders on (a) high mass diffraction (b) double pomeron exchange, from the ISR through the Sp{bar p}S to the Tevatron. I emphasize an experimental approach to the question: ``What is the pomeron?``

  6. Fresnel Diffraction for CTR Microbunching

    NASA Astrophysics Data System (ADS)

    Tikhoplav, R.; Knyazik, A.; Rosenzweig, J. B.; Andonian, G.

    2009-01-01

    Laser beams of high intensities are routinely used for IFEL experiments. Such beams can potentially destroy microbunching diagnostic tools such as coherent transition radiation foils due to their low damage thresholds. Near-field Fresnel diffraction scheme for termination of CO2 laser beam has been experimentally studied and is presented in this paper. Novel THz camera was utilized for such study.

  7. Mathmatical modeling for diffractive optics

    NASA Technical Reports Server (NTRS)

    Dobson, David; Cox, J. Allen

    1993-01-01

    We consider a 'diffractive optic' to be a biperiodic surface separating two half-spaces, each having constant constitutive parameters; within a unit cell of the periodic surface and across the transition zone between the two half-spaces, the constitutive parameters can be a continuous, complex-valued function. Mathematical models for diffractive optics have been developed, and implemented as numerical codes, both for the 'direct' problem and for the 'inverse' problem. In problems of the 'direct' class, the diffractive optic is specified, and the full set of Maxwell's equations is cast in a variational form and solved numerically by a finite element approach. This approach is well-posed in the sense that existence and uniqueness of the solution can be proved and specific convergence conditions can be derived. An example of a metallic grating at a Wood anomaly is presented as a case where other approaches are known to have convergence problems. In problems of the 'inverse' class, some information about the diffracted field (e.g., the far-field intensity) is given, and the problem is to find the periodic structure in some optimal sense. Two approaches are described: phase reconstruction in the far-field approximation; and relaxed optimal design based on the Helmholtz equation. Practical examples are discussed for each approach to the inverse problem, including array generators in the far-field case and antireflective structures for the relaxed optimal design.

  8. Fresnel diffraction plates are simple and inexpensive

    NASA Technical Reports Server (NTRS)

    Hoover, R. B.

    1967-01-01

    Fresnel plate demonstrates diffraction phenomena simply and inexpensively. A large number of identical diffracting apertures are made in random orientation on photographic film. When a small source of light is viewed through the plate, the diffraction pattern typical of the diffracting aperture is readily seen.

  9. Electro-Optic Diffraction Grating Tuned Laser.

    DTIC Science & Technology

    The patent concerns an electro - optic diffraction grating tuned laser comprising a laser medium, output mirror, retro-reflective grating and an electro - optic diffraction grating beam deflector positioned between the laser medium and the reflective diffraction grating. An optional angle multiplier may be used between the electro - optic diffraction grating and the reflective grating.

  10. Stratified volume diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Chambers, Diana Marie

    2000-11-01

    Gratings with high diffraction efficiency into a single order find use in applications ranging from optical interconnects to beam steering. Such gratings have been realized with volume holographic, blazed, and diffractive optical techniques. However, each of these methods has limitations that restrict the range of applications in which they can be used. In this work an alternate, novel approach and method for creating high efficiency gratings has been developed. These new gratings are named stratified volume diffractive optical elements (SVDOE's). In this approach diffractive optic techniques are used to create an optical structure that emulates volume grating behavior. An SVDOE consists of binary gratings interleaved with homogeneous layers in a multi-layer, stratified grating structure. The ridges of the binary gratings form fringe planes analogous to those of a volume hologram. The modulation and diffraction of an incident beam, which occur concurrently in a volume grating, are achieved sequentially by the grating layers and the homogeneous layers, respectively. The layers in this type of structure must be fabricated individually, which introduces the capability to laterally shift the binary grating layers relative to one another to create a grating with slanted fringe planes. This allows an element to be designed with high diffraction efficiency into the first order for any arbitrary angle of incidence. A systematic design process has been developed for SVDOE's. Optimum modulation depth of the SVDOE is determined analytically and the number of grating layers along with the thickness of homogeneous layers is determined by numerical simulation. A rigorous electromagnetic simulation of the diffraction properties of multi-layer grating structures, based on the Rigorous Coupled-Wave Analysis (RCWA) algorithm, was developed and applied to SVDOE performance prediction. Fabrication of an SVDOE structure presents unique challenges. Microfabrication combined with

  11. Infrared Metamaterials for Diffractive Optics

    NASA Astrophysics Data System (ADS)

    Tsai, Yu-Ju

    Intense developments in optical metamaterials have led to a renaissance in several optics fields. Metamaterials, artificially structured media, provide several additional degrees of freedom that cannot be accessed with conventional materials. For example, metamaterials offer a convenient and precise way to explore a wide range of refractive indices, including negative values. In this dissertation, I introduce the idea of metamaterial based diffractive optics. Merging diffractive optics with metamaterials has several benefits, including access to almost continuous phase profiles and a wide range of available controlled anisotropy. I demonstrate this concept with several examples. I begin with an example of metamaterial based blazed diffraction grating using gradient index metamaterials for lambda = 10.6 microm. A series of non-resonant metamaterial elements were designed and fabricated to mimic a saw-tooth refractive index profile with a linear index variation of Deltan = 3.0. The linear gradient profile is repeated periodically to form the equivalent of a blazed grating, with the gradient occurring across a spatial distance of 61 microm. The index gradient is confirmed by comparing the measured magnitudes of the -1, 0 and +1 diffracted orders to those obtained from full wave simulations. In addition to a metamaterial grating, a metamaterial based computer-generated phase hologram was designed by implementing the Gerchberg-Saxton (GS) iterative algorithm to form a 2D phase panel. A three layer metamaterial hologram was fabricated, with the size of 750 microm x 750 microm. Each pixel is comprised of 5 x 5 metamaterial elements. This simple demonstration shows the potential for practical applications of metamaterial based diffractive optics. The demand for compact and integrated optoelectronic systems increases the urgency for optical components that can simultaneously perform various functions. This dissertation also presents an optical element capable of

  12. Diffraction of cosine-Gaussian-correlated Schell-model beams.

    PubMed

    Pan, Liuzhan; Ding, Chaoliang; Wang, Haixia

    2014-05-19

    The expression of spectral density of cosine-Gaussian-correlated Schell-model (CGSM) beams diffracted by an aperture is derived, and used to study the changes in the spectral density distribution of CGSM beams upon propagation, where the effect of aperture diffraction is emphasized. It is shown that, comparing with that of GSM beams, the spectral density distribution of CGSM beams diffracted by an aperture has dip and shows dark hollow intensity distribution when the order-parameter n is big enough. The central intensity increases with increasing truncation parameter of aperture. The comparative study of spectral density distributions of CGSM beams with aperture and that of without aperture is performed. Furthermore, the effect of order-parameter n and spatial coherence of CGSM beams on the spectral density distribution is discussed in detail. The results obtained may be useful in optical particulate manipulation.

  13. Heavy Stars Thrive among Heavy Elements

    NASA Astrophysics Data System (ADS)

    2002-08-01

    , with a sprinkling of the light element lithium. At our epoch, the visible ("baryonic") matter in the Universe still mostly consists of hydrogen and helium. However, progressively heavier elements have been built up via fusion processes in the interior of stars ever since the Big Bang. Some of the heaviest elements are also produced when massive stars die in gigantic stellar explosions, observed as "supernovae". This gradual process, referred to as "chemical evolution" , occurs with different speeds in different regions of the Universe, being fastest in those regions where star formation is most intense. In the relatively "quiet" region of the Milky Way galaxy where our Solar System was born some 4,600 million years ago, it took nearly 10,000 million years to produce all the heavy elements now found in our neighbourhood . Contrarily, in the innermost regions ( the "nuclei" ) of normal galaxies and especially in so-called "active galaxies", the same or even higher heavy-element "enrichment" levels were reached in much shorter time, less than about 1,000 to 2,000 million years. This is the result of observations of particularly active galaxy nuclei ("quasars") in the distant (i.e., early) Universe. Star formation in highly enriched environments Little is presently known about such highly enriched environments. Since astronomers refer to elements heavier than hydrogen and helium as "metals" , they talk about "metal-rich" regions . This is readily observable from the presence of strong lines from heavier elements in the spectra of the interstellar gas in such regions. A central, still unresolved question is whether under such special conditions, stars can still form with the same diversity of masses, as this happens in other, less extreme areas of the Universe . Indeed, some current theories of star formation and certain indirect observations appear to indicate that very heavy stars - with masses more than 20 - 30 times that of our Sun - could not possibly form in metal

  14. Digital diffractive optics: Have diffractive optics entered mainstream industry yet?

    NASA Astrophysics Data System (ADS)

    Kress, Bernard; Hejmadi, Vic

    2010-05-01

    When a new technology is integrated into industry commodity products and consumer electronic devices, and sold worldwide in retail stores, it is usually understood that this technology has then entered the realm of mainstream technology and therefore mainstream industry. Such a leap however does not come cheap, as it has a double edge sword effect: first it becomes democratized and thus massively developed by numerous companies for various applications, but also it becomes a commodity, and thus gets under tremendous pressure to cut down its production and integration costs while not sacrificing to performance. We will show, based on numerous examples extracted from recent industry history, that the field of Diffractive Optics is about to undergo such a major transformation. Such a move has many impacts on all facets of digital diffractive optics technology, from the optical design houses to the micro-optics foundries (for both mastering and volume replication), to the final product integrators or contract manufacturers. The main causes of such a transformation are, as they have been for many other technologies in industry, successive technological bubbles which have carried and lifted up diffractive optics technology within the last decades. These various technological bubbles have been triggered either by real industry needs or by virtual investment hype. Both of these causes will be discussed in the paper. The adjective ""digital"" in "digital diffractive optics" does not refer only, as it is done in digital electronics, to the digital functionality of the element (digital signal processing), but rather to the digital way they are designed (by a digital computer) and fabricated (as wafer level optics using digital masking techniques). However, we can still trace a very strong similarity between the emergence of micro-electronics from analog electronics half a century ago, and the emergence of digital optics from conventional optics today.

  15. Heavy quark masses

    NASA Technical Reports Server (NTRS)

    Testa, Massimo

    1990-01-01

    In the large quark mass limit, an argument which identifies the mass of the heavy-light pseudoscalar or scalar bound state with the renormalized mass of the heavy quark is given. The following equation is discussed: m(sub Q) = m(sub B), where m(sub Q) and m(sub B) are respectively the mass of the heavy quark and the mass of the pseudoscalar bound state.

  16. Production of heavy water

    DOEpatents

    Spencer, Larry S.; Brown, Sam W.; Phillips, Michael R.

    2017-06-06

    Disclosed are methods and apparatuses for producing heavy water. In one embodiment, a catalyst is treated with high purity air or a mixture of gaseous nitrogen and oxygen with gaseous deuterium all together flowing over the catalyst to produce the heavy water. In an alternate embodiment, the deuterium is combusted to form the heavy water. In an alternate embodiment, gaseous deuterium and gaseous oxygen is flowed into a fuel cell to produce the heavy water. In various embodiments, the deuterium may be produced by a thermal decomposition and distillation process that involves heating solid lithium deuteride to form liquid lithium deuteride and then extracting the gaseous deuterium from the liquid lithium deuteride.

  17. Diffraction of Gaussian wave packets by a single slit

    NASA Astrophysics Data System (ADS)

    Zecca, A.

    2011-02-01

    A two-dimensional formulation of particle diffraction by a single slit is proposed within Schrödinger QM. The study is done in terms of Gaussian wave packets. A "confinement" assumption is considered together with a previous "truncation" assumption when the wave packet passes the slit. In the limiting situation of entering Gaussian wave packet peaked in the transverse-momentum probability distribution, the diffraction pattern results in an unaltered central maximum with lateral maxima narrower and higher than in the absence of the confinement assumption. For entering wave packets peaked in the transverse position probability distribution, the diffraction pattern consists of a central Gaussian spot with lateral diffraction maxima, not present in the absence of the "confinement" assumption, whose visibility depends on the configuration of the parameters. With a different analysis, a similar effect was obtained also in G. Kalbermann (J. Phys. A: Math. Gen. 35, 4599 (2002)). Its experimental verification seems of interest to discriminate between Schrödinger QM and stochastic electrodynamics with spin.

  18. Diffraction operators in paraxial approach

    NASA Astrophysics Data System (ADS)

    Lasso, William; Navas, Marianela; Añez, Liz; Urdaneta, Romer; Díaz, Leonardo; Torres, César O.

    2014-07-01

    Nowadays, research in the field of science education points to the creation of alternative ways of teaching contents encouraging the development of more elaborate reasoning, where a high degree of abstraction and generalization of scientific knowledge prevails. On that subject, this research shows a didactic alternative proposal for the construction of Fresnel and Fraunhoffer diffraction concepts applying the Fourier transform technique in the study of electromagnetic waves propagation in free space. Curvature transparency and Fourier sphere operators in paraxial approximation are used in order to make the usual laborious mathematical approach easier. The main result shows that the composition of optic metaxial operators results in the discovery of a simpler way out of the standard electromagnetic wave propagation in free space between a transmitter and a receptor separated from a given distance. This allows to state that the didactic proposal shown encourages the construction of Fresnel and Fraunhoffer diffraction concepts in a more effective and easier way than the traditional teaching.

  19. dxtbx: the diffraction experiment toolbox.

    PubMed

    Parkhurst, James M; Brewster, Aaron S; Fuentes-Montero, Luis; Waterman, David G; Hattne, Johan; Ashton, Alun W; Echols, Nathaniel; Evans, Gwyndaf; Sauter, Nicholas K; Winter, Graeme

    2014-08-01

    Data formats for recording X-ray diffraction data continue to evolve rapidly to accommodate new detector technologies developed in response to more intense light sources. Processing the data from single-crystal X-ray diffraction experiments therefore requires the ability to read, and correctly interpret, image data and metadata from a variety of instruments employing different experimental representations. Tools that have previously been developed to address this problem have been limited either by a lack of extensibility or by inconsistent treatment of image metadata. The dxtbx software package provides a consistent interface to both image data and experimental models, while supporting a completely generic user-extensible approach to reading the data files. The library is written in a mixture of C++ and Python and is distributed as part of the cctbx under an open-source licence at http://cctbx.sourceforge.net.

  20. Phase Aberrations in Diffraction Microscopy

    SciTech Connect

    Marchesini, S; Chapman, H N; Barty, A; Howells, M R; Spence, J H; Cui, C; Weierstall, U; Minor, A M

    2005-09-29

    In coherent X-ray diffraction microscopy the diffraction pattern generated by a sample illuminated with coherent x-rays is recorded, and a computer algorithm recovers the unmeasured phases to synthesize an image. By avoiding the use of a lens the resolution is limited, in principle, only by the largest scattering angles recorded. However, the imaging task is shifted from the experiment to the computer, and the algorithm's ability to recover meaningful images in the presence of noise and limited prior knowledge may produce aberrations in the reconstructed image. We analyze the low order aberrations produced by our phase retrieval algorithms. We present two methods to improve the accuracy and stability of reconstructions.

  1. Deterministic Bragg Coherent Diffraction Imaging.

    PubMed

    Pavlov, Konstantin M; Punegov, Vasily I; Morgan, Kaye S; Schmalz, Gerd; Paganin, David M

    2017-04-25

    A deterministic variant of Bragg Coherent Diffraction Imaging is introduced in its kinematical approximation, for X-ray scattering from an imperfect crystal whose imperfections span no more than half of the volume of the crystal. This approach provides a unique analytical reconstruction of the object's structure factor and displacement fields from the 3D diffracted intensity distribution centred around any particular reciprocal lattice vector. The simple closed-form reconstruction algorithm, which requires only one multiplication and one Fourier transformation, is not restricted by assumptions of smallness of the displacement field. The algorithm performs well in simulations incorporating a variety of conditions, including both realistic levels of noise and departures from ideality in the reference (i.e. imperfection-free) part of the crystal.

  2. Anomalous diffraction in hyperbolic materials

    NASA Astrophysics Data System (ADS)

    Alberucci, Alessandro; Jisha, Chandroth P.; Boardman, Allan D.; Assanto, Gaetano

    2016-09-01

    We demonstrate that light is subject to anomalous (i.e., negative) diffraction when propagating in the presence of hyperbolic dispersion. We show that light propagation in hyperbolic media resembles the dynamics of a quantum particle of negative mass moving in a two-dimensional potential. The negative effective mass implies time reversal if the medium is homogeneous. Such property paves the way to diffraction compensation, i.e., spatial analog of dispersion compensating fibers in the temporal domain. At variance with materials exhibiting standard elliptic dispersion, in inhomogeneous hyperbolic materials light waves are pulled towards regions with a lower refractive index. In the presence of a Kerr-like optical response, bright (dark) solitons are supported by a negative (positive) nonlinearity.

  3. Perturbation theory in electron diffraction

    NASA Astrophysics Data System (ADS)

    Bakken, L. N.; Marthinsen, K.; Hoeier, R.

    1992-12-01

    The Bloch-wave approach is used for discussing multiple inelastic electron scattering and higher-order perturbation theory in inelastic high-energy electron diffraction. In contrast to previous work, the present work describes three-dimensional diffraction so that higher-order Laue zone (HOLZ) effects are incorporated. Absorption is included and eigenvalues and eigenvectors are calculated from a structure matrix with the inclusion of an absorptive potential. Centrosymmetric as well as non-centrosymmetric crystal structures are allowed. An iteration method with a defined generalized propagation function for solving the inelastic coupling equations is described. It is shown that a similar iteration method with the same propagation function can be used for obtaining higher-order perturbation terms for the wave-function when a perturbation is added to the crystal potential. Finally, perturbation theory by matrix calculations when a general perturbation is added to the structure matrix is considered.

  4. Diffraction moire: The dynamic regime

    SciTech Connect

    Deason, V.A.; Epstein, J.S.; Reuter, W.G.

    1987-01-01

    The technique of diffraction moire interferometry has been applied to numerous static and slowly changing stress configurations. The method has now been extended to the study of dynamic loading events, especially to the interaction of dynamic stress waves with such flaws as cracks or with the variations in composition found in composite materials. A pulsed ruby laser was used to provide the rapid (20 ns wide), brilliant and coherent illumination required for these studies. The technique and several specific applications are described.

  5. Industrial applications of neutron diffraction

    SciTech Connect

    Felcher, G.P.

    1989-01-01

    Neutron diffraction (or, to be more general, neutron scattering) is a most versatile and universal tool, which has been widely employed to probe the structure, the dynamics and the magnetism of condensed matter. Traditionally used for fundamental research in solid state physics, this technique more recently has been applied to problems of immediate industrial interest, as illustrated in examples covering the main fields of endeavour. 14 refs., 14 figs.

  6. Confinement, Turbulence and Diffraction Catastrophes

    NASA Astrophysics Data System (ADS)

    Blaizot, J.-P.; Nowak, M. A.

    2009-08-01

    Many features of the large N transition that occurs in the spectral density of Wilson loops as a function of loop area (observed recently in numerical simulations of Yang-Mills theory by Narayanan and Neuberger) can be captured by a simple Burgers equation used to model turbulence. Spectral shock waves that precede this asymptotic limit exhibit universal scaling with N, with indices that can be related to Berry indices for diffraction catastrophes.

  7. Neutron diffraction and Vitamin E

    NASA Astrophysics Data System (ADS)

    Harroun, T. A.

    2010-11-01

    It is generally accepted that neutron diffraction from model membrane systems is an effective biophysical technique for determining membrane structure. Here we describe an example of how deuterium labelling can elucidate the location of specific membrane soluble molecules, including a brief discussion of the technique itself. We show that deuterium labelled α-tocopherol sits upright in the bilayer, as might be expected, but at very different locations within the bilayer, depending on the degree of lipid chain unsaturation.

  8. Aberrations of diffracted wave fields: distortion.

    PubMed

    Harvey, James E; Bogunovic, Dijana; Krywonos, Andrey

    2003-03-01

    Near-field diffraction patterns are merely aberrated Fraunhofer diffraction patterns. These aberrations, inherent to the diffraction process, provide insight and understanding into wide-angle diffraction phenomena. Nonparaxial patterns of diffracted orders produced by a laser beam passing through a grating and projected upon a plane screen exhibit severe distortion (W311). This distortion is an artifact of the configuration chosen to observe diffraction patterns. Grating behavior expressed in terms of the direction cosines of the propagation vectors of the incident and diffracted orders exhibits no distortion. Use of a simple direction cosine diagram provides an elegant way to deal with nonparaxial diffraction patterns, particularly when large obliquely incident beams produce conical diffraction.

  9. Diffraction Techniques in Structural Biology

    PubMed Central

    Egli, Martin

    2010-01-01

    A detailed understanding of chemical and biological function and the mechanisms underlying the activities ultimately requires atomic-resolution structural data. Diffraction-based techniques such as single-crystal X-ray crystallography, electron microscopy and neutron diffraction are well established and have paved the road to the stunning successes of modern-day structural biology. The major advances achieved in the last 20 years in all aspects of structural research, including sample preparation, crystallization, the construction of synchrotron and spallation sources, phasing approaches and high-speed computing and visualization, now provide specialists and non-specialists alike with a steady flow of molecular images of unprecedented detail. The present chapter combines a general overview of diffraction methods with a step-by-step description of the process of a single-crystal X-ray structure determination experiment, from chemical synthesis or expression to phasing and refinement, analysis and quality control. For novices it may serve as a stepping-stone to more in-depth treatises of the individual topics. Readers relying on structural information for interpreting functional data may find it a useful consumer guide. PMID:20517991

  10. Submicron X-ray diffraction

    SciTech Connect

    MacDowell, Alastair; Celestre, Richard; Tamura, Nobumichi; Spolenak, Ralph; Valek, Bryan; Brown, Walter; Bravman, John; Padmore, Howard; Batterman, Boris; Patel, Jamshed

    2000-08-17

    At the Advanced Light Source in Berkeley the authors have instrumented a beam line that is devoted exclusively to x-ray micro diffraction problems. By micro diffraction they mean those classes of problems in Physics and Materials Science that require x-ray beam sizes in the sub-micron range. The instrument is for instance, capable of probing a sub-micron size volume inside micron sized aluminum metal grains buried under a silicon dioxide insulating layer. The resulting Laue pattern is collected on a large area CCD detector and automatically indexed to yield the grain orientation and deviatoric (distortional) strain tensor of this sub-micron volume. A four-crystal monochromator is then inserted into the beam, which allows monochromatic light to illuminate the same part of the sample. Measurement of diffracted photon energy allows for the determination of d spacings. The combination of white and monochromatic beam measurements allow for the determination of the total strain/stress tensor (6 components) inside each sub-micron sized illuminated volume of the sample.

  11. Diffraction Techniques in Structural Biology

    PubMed Central

    Egli, Martin

    2016-01-01

    A detailed understanding of chemical and biological function and the mechanisms underlying the molecular activities ultimately requires atomic-resolution structural data. Diffraction-based techniques such as single-crystal X-ray crystallography, electron microscopy, and neutron diffraction are well established and they have paved the road to the stunning successes of modern-day structural biology. The major advances achieved in the last 20 years in all aspects of structural research, including sample preparation, crystallization, the construction of synchrotron and spallation sources, phasing approaches, and high-speed computing and visualization, now provide specialists and nonspecialists alike with a steady flow of molecular images of unprecedented detail. The present unit combines a general overview of diffraction methods with a detailed description of the process of a single-crystal X-ray structure determination experiment, from chemical synthesis or expression to phasing and refinement, analysis, and quality control. For novices it may serve as a stepping-stone to more in-depth treatises of the individual topics. Readers relying on structural information for interpreting functional data may find it a useful consumer guide. PMID:27248784

  12. Diffraction-Coupled, Phase-Locked Semiconductor Laser Array

    NASA Technical Reports Server (NTRS)

    Katz, Joseph; Yariv, Amnon; Margalit, Shlomo

    1988-01-01

    Stable, narrow far field produced. Array of lasers fabricated on single chip. Individual laser waveguides isolated from each other except in end portions, where diffraction coupling takes place. Radiation pattern far from laser array has single, sharp central lobe when all lasers operate in phase with each other. Shape of lobe does not vary appreciably with array current. Applications include recording, printing, and range finding.

  13. Experimental overview on heavy-flavor production

    NASA Astrophysics Data System (ADS)

    Grelli, Alessandro

    2017-04-01

    Hadrons containing heavy-flavors are unique probes of the properties of the hot and dense QCD medium produced in heavy-ion collisions. Due to their large masses, heavy quarks are produced at the initial stage of the collision, almost exclusively via hard partonic scattering processes. Therefore, they are expected to experience the full collision history propagating through and interacting with the QCD medium. The parton energy loss, which is sensitive to the transport coefficients of the produced medium, can be studied experimentally by measuring the nuclear modification factor which accounts for the modification of the heavy-flavored hadron yield in Pb-Pb collisions with respect to pp collisions. In semi-central Pb-Pb collisions, the degree of thermalization of charm quarks in the QCD medium can be accessed via the measurement of the heavy flavor elliptic flow v2 at low pT. Furthermore, the measurement of heavy-flavors production in pp collisions allows testing the perturbative QCD calculations. The PHENIX and STAR Collaborations at the Relativistic Heavy-Ion Collider and ALICE, CMS and ATLAS Collaborations at the Large Hadron Collider have measured the production of charmonium and bottonium states as well as open heavy flavor hadrons via their hadronic and semi-leptonic decays at mid-rapidity and in the semi-muonic decay channel at forward rapidity in pp, p-A and A-A collisions in an energy domain that ranges from \\sqrt{s} = 0.2 TeV to \\sqrt{s} = 13 TeV in pp collisions and from \\sqrt{{s}{{NN}}} = 0.2 TeV to \\sqrt{{s}{{NN}}} = 5.02 TeV in A-A collisions. In this contribution the latest experimental results will be reviewed.

  14. Spatial-energy characteristics of the focal areas of bifocal diffractive-refractive intraocular lenses

    NASA Astrophysics Data System (ADS)

    Lenkova, G. A.

    2017-01-01

    Computer simulation was performed for the measurement process of the parameters of MIOL-Akkord bifocal diffractive-refractive lenses in which the central area of the diffractive element is reduced and spherical aberrations of the eye are compensated. The spatial-energy characteristics of an ideal diffractive lens are preliminarily calculated using existing formulas. The simulation of the process of controlling the intraocular lens parameters has shown that the intensity distribution along the optical axis does not characterize the diffraction efficiency, which is the total (integrated) intensity in the beam cross section at the focus. It has been found that due to the mutual influence of diffraction orders, it is difficult to measure the absolute diffraction efficiency and it is better to evaluate only the relative efficiency.

  15. Triple Bragg diffraction in paratellurite crystal

    NASA Astrophysics Data System (ADS)

    Kotov, V. M.; Averin, S. V.; Voronko, A. I.; Kotov, E. V.; Tikhomirov, S. A.

    2017-07-01

    Triple Bragg diffraction in a paratellurite crystal has been considered for the case when the plane of diffraction is oblique to the optical axis of the crystal. It has been shown that effective photoelastic constants for isotropic and anisotropic diffraction depend on the inclination of the plane of diffraction insignificantly. Triple Bragg diffraction of 0.63-μm coherent radiation in paratellurite at a 47.3-MHz slow acoustic wave has been experimentally demonstrated. For an optical power of 0.69 W delivered to a piezoconverter, the relative intensities of diffraction orders equal 0.4, 0.4, 0.1, and 0.1, respectively.

  16. Flooding in Central China

    NASA Technical Reports Server (NTRS)

    2002-01-01

    During the summer of 2002, frequent, heavy rains gave rise to floods and landslides throughout China that have killed over 1,000 people and affected millions. This false-color image of the western Yangtze River and Dongting Lake in central China was acquired on August 21, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. (right) The latest flooding crisis in China centers on Dingtong Lake in the center of the image. Heavy rains have caused it to swell over its banks and swamp lakefront towns in the province of Hunan. As of August 23, 2002, more than 250,000 people have been evacuated, and over one million people have been brought in to fortify the dikes around the lake. Normally the lake would appear much smaller and more defined in the MODIS image. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.

  17. Flooding in Central China

    NASA Technical Reports Server (NTRS)

    2002-01-01

    During the summer of 2002, frequent, heavy rains gave rise to floods and landslides throughout China that have killed over 1,000 people and affected millions. This false-color image of the western Yangtze River and Dongting Lake in central China was acquired on August 21, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. (right) The latest flooding crisis in China centers on Dingtong Lake in the center of the image. Heavy rains have caused it to swell over its banks and swamp lakefront towns in the province of Hunan. As of August 23, 2002, more than 250,000 people have been evacuated, and over one million people have been brought in to fortify the dikes around the lake. Normally the lake would appear much smaller and more defined in the MODIS image. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.

  18. Quantum critical behavior in heavy electron materials.

    PubMed

    Yang, Yi-feng; Pines, David

    2014-06-10

    Quantum critical behavior in heavy electron materials is typically brought about by changes in pressure or magnetic field. In this paper, we develop a simple unified model for the combined influence of pressure and magnetic field on the effectiveness of the hybridization that plays a central role in the two-fluid description of heavy electron emergence. We show that it leads to quantum critical and delocalization lines that accord well with those measured for CeCoIn5, yields a quantitative explanation of the field and pressure-induced changes in antiferromagnetic ordering and quantum critical behavior measured for YbRh2Si2, and provides a valuable framework for describing the role of magnetic fields in bringing about quantum critical behavior in other heavy electron materials.

  19. High energy heavy ions: techniques and applications

    SciTech Connect

    Alonso, J.R.

    1985-04-01

    Pioneering work at the Bevalac has given significant insight into the field of relativistic heavy ions, both in the development of techniques for acceleration and delivery of these beams as well as in many novel areas of applications. This paper will outline our experiences at the Bevalac; ion sources, low velocity acceleration, matching to the synchrotron booster, and beam delivery. Applications discussed will include the observation of new effects in central nuclear collisions, production of beams of exotic short-lived (down to 1 ..mu..sec) isotopes through peripheral nuclear collisions, atomic physics with hydrogen-like uranium ions, effects of heavy ''cosmic rays'' on satellite equipment, and an ongoing cancer radiotherapy program with heavy ions. 39 refs., 6 figs., 1 tab.

  20. Quantum critical behavior in heavy electron materials

    PubMed Central

    Yang, Yi-feng; Pines, David

    2014-01-01

    Quantum critical behavior in heavy electron materials is typically brought about by changes in pressure or magnetic field. In this paper, we develop a simple unified model for the combined influence of pressure and magnetic field on the effectiveness of the hybridization that plays a central role in the two-fluid description of heavy electron emergence. We show that it leads to quantum critical and delocalization lines that accord well with those measured for CeCoIn5, yields a quantitative explanation of the field and pressure-induced changes in antiferromagnetic ordering and quantum critical behavior measured for YbRh2Si2, and provides a valuable framework for describing the role of magnetic fields in bringing about quantum critical behavior in other heavy electron materials. PMID:24912172

  1. Investigation Of Far-Field Diffraction

    NASA Technical Reports Server (NTRS)

    Wang, Yaujen; Scholl, Marija S.

    1993-01-01

    Report describes experimental investigation of far-field diffracton by normally illuminated circular apertures with diameters of several wavelengths of incident light. Purpose of investigation to determine whether Keller's "geometrical" theory of diffraction valid for diffraction phenomena of this kind.

  2. Crystallography: Resolution beyond the diffraction limit

    NASA Astrophysics Data System (ADS)

    Shen, Jian-Ren

    2016-02-01

    A method has been devised that extends the resolution of X-ray crystal structures beyond the diffraction limit. This might help to improve the visualization of structures of proteins that form 'poorly diffracting' crystals. See Letter p.202

  3. Diffractive optics: Design, fabrication, and applications

    NASA Technical Reports Server (NTRS)

    Morris, G. Michael

    1993-01-01

    The topics are presented in viewgraph form and include the following: features, applications, surface relief diffractive optics, optical data storage, waveguide lenses, diffractive lense imaging, phase grating synthesis, sub-wavelength structured surfaces, etc.

  4. Final Report: Algorithms for Diffractive Microscopy

    SciTech Connect

    Elser, Veit

    2010-10-08

    The phenomenal coherence and brightness of x-ray free-electron laser light sources, such as the LCLS at SLAC, have the potential of revolutionizing the investigation of structure and dynamics in the nano-domain. However, this potential will go unrealized without a similar revolution in the way the data are analyzed. While it is true that the ambitious design parameters of the LCLS have been achieved, the prospects of realizing the most publicized goal of this instrument — the imaging of individual bio-particles — remains daunting. Even with 10{sup 12} photons per x-ray pulse, the feebleness of the scattering process represents a fundamental limit that no amount of engineering ingenuity can overcome. Large bio-molecules will scatter on the order of only 10{sup 3} photons per pulse into a detector with 106 pixels; the diffraction “images” will be virtually indistinguishable from noise. Averaging such noisy signals over many pulses is not possible because the particle orientation cannot be controlled. Each noisy laser snapshot is thus confounded by the unknown viewpoint of the particle. Given the heavy DOE investment in LCLS and the profound technical challenges facing single-particle imaging, the final two years of this project have concentrated on this effort. We are happy to report that we succeeded in developing an extremely efficient algorithm that can reconstruct the shapes of particles at even the extremes of noise expected in future LCLS experiments with single bio-particles. Since this is the most important outcome of this project, the major part of this report documents this accomplishment. The theoretical techniques that were developed for the single-particle imaging project have proved useful in other imaging problems that are described at the end of the report.

  5. Coherent Diffractive Imaging at LCLS

    NASA Astrophysics Data System (ADS)

    Schulz, Joachim

    2010-03-01

    Soft x-ray FEL light sources produce ultrafast x-ray pulses with outstanding high peak brilliance. This might enable the structure determination of proteins that cannot be crystallized. The deposited energy would destroy the molecules completely, but owing to the short pulses the destruction will ideally only happen after the termination of the pulse. In order to address the many challenges that we face in attempting molecular diffraction, we have carried out experiments in coherent diffraction from protein nanocrystals at the Linac Coherent Light Source (LCLS) at SLAC. The periodicity of these objects gives us much higher scattering signals than uncrystallized proteins would. The crystals are filtered to sizes less than 2 micron, and delivered to the pulsed X-ray beam in a liquid jet. The effects of pulse duration and fluence on the high-resolution structure of the crystals have been studied. Diffraction patterns are recorded at a repetition rate of 30 Hz with pnCCD detectors. This allows us to take 108,000 images per hour. With 2-mega-pixel-detectors this gives a data-rate of more than 400 GB per hour. The automated sorting and evaluation of hundreds of thousands images is another challenge of this kind of experiments. Preliminary results will be presented on our first LCLS experiments. This work was carried out as part of a collaboration, for which Henry Chapman is the spokesperson. The collaboration consists of CFEL DESY, Arizona State University, SLAC, Uppsala University, LLNL, The University of Melbourne, LBNL, the Max Planck Institute for Medical Research, and the Max Planck Advanced Study Group (ASG) at the CFEL. The experiments were carried out using the CAMP apparatus, which was designed and built by the Max Planck ASG at CFEL. The LCLS is operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences.

  6. 50 years of fiber diffraction.

    PubMed

    Holmes, Kenneth C

    2010-05-01

    In 1955 Ken Holmes started working on tobacco mosaic virus (TMV) as a research student with Rosalind Franklin at Birkbeck College, London. Afterward he spent 18months as a post doc with Don Caspar and Carolyn Cohen at the Children's Hospital, Boston where he continued the work on TMV and also showed that the core of the thick filament of byssus retractor muscle from mussels is made of two-stranded alpha-helical coiled-coils. Returning to England he joined Aaron Klug's group at the newly founded Laboratory of Molecular Biology in Cambridge. Besides continuing the TMV studies, which were aimed at calculating the three-dimensional density map of the virus, he collaborated with Pringle's group in Oxford to show that two conformation of the myosin cross-bridge could be identified in insect flight muscle. In 1968 he opened the biophysics department at the Max Planck Institute for Medical Research in Heidelberg, Germany. With Gerd Rosenbaum he initiated the use of synchrotron radiation as a source for X-ray diffraction. In his lab the TMV structure was pushed to 4A resolution and showed how the RNA binds to the protein. With his co-workers he solved the structure of g-actin as a crystalline complex and then solved the structure of the f-actin filament by orientating the g-actin structure so as to give the f-actin fiber diffraction pattern. He was also able to solve the structure of the complex of actin with tropomyosin from fiber diffraction.

  7. The early development of neutron diffraction: science in the wings of the Manhattan Project.

    PubMed

    Mason, T E; Gawne, T J; Nagler, S E; Nestor, M B; Carpenter, J M

    2013-01-01

    Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan Project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurement of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor. Subsequent work by Wollan and Clifford G. Shull, who joined Wollan's group at Oak Ridge in 1946, laid the foundations for widespread application of neutron diffraction as an important research tool.

  8. Issues in Optical Diffraction Theory

    PubMed Central

    Mielenz, Klaus D.

    2009-01-01

    This paper focuses on unresolved or poorly documented issues pertaining to Fresnel’s scalar diffraction theory and its modifications. In Sec. 2 it is pointed out that all thermal sources used in practice are finite in size and errors can result from insufficient coherence of the optical field. A quarter-wave criterion is applied to show how such errors can be avoided by placing the source at a large distance from the aperture plane, and it is found that in many cases it may be necessary to use collimated light as on the source side of a Fraunhofer experiment. If these precautions are not taken the theory of partial coherence may have to be used for the computations. In Sec. 3 it is recalled that for near-zone computations the Kirchhoff or Rayleigh-Sommerfeld integrals are applicable, but fail to correctly describe the energy flux across the aperture plane because they are not continuously differentiable with respect to the assumed geometrical field on the source side. This is remedied by formulating an improved theory in which the field on either side of a semi-reflecting screen is expressed as the superposition of mutually incoherent components which propagate in the opposite directions of the incident and reflected light. These components are defined as linear combinations of the Rayleigh-Sommerfeld integrals, so that they are rigorous solutions of the wave equation as well as continuously differentiable in the aperture plane. Algorithms for using the new theory for computing the diffraction patterns of circular apertures and slits at arbitrary distances z from either side of the aperture (down to z = ± 0.0003 λ) are presented, and numerical examples of the results are given. These results show that the incident geometrical field is modulated by diffraction before it reaches the aperture plane while the reflected field is spilled into the dark space. At distances from the aperture which are large compared to the wavelength λ these field expressions are

  9. Issues in Optical Diffraction Theory.

    PubMed

    Mielenz, Klaus D

    2009-01-01

    This paper focuses on unresolved or poorly documented issues pertaining to Fresnel's scalar diffraction theory and its modifications. In Sec. 2 it is pointed out that all thermal sources used in practice are finite in size and errors can result from insufficient coherence of the optical field. A quarter-wave criterion is applied to show how such errors can be avoided by placing the source at a large distance from the aperture plane, and it is found that in many cases it may be necessary to use collimated light as on the source side of a Fraunhofer experiment. If these precautions are not taken the theory of partial coherence may have to be used for the computations. In Sec. 3 it is recalled that for near-zone computations the Kirchhoff or Rayleigh-Sommerfeld integrals are applicable, but fail to correctly describe the energy flux across the aperture plane because they are not continuously differentiable with respect to the assumed geometrical field on the source side. This is remedied by formulating an improved theory in which the field on either side of a semi-reflecting screen is expressed as the superposition of mutually incoherent components which propagate in the opposite directions of the incident and reflected light. These components are defined as linear combinations of the Rayleigh-Sommerfeld integrals, so that they are rigorous solutions of the wave equation as well as continuously differentiable in the aperture plane. Algorithms for using the new theory for computing the diffraction patterns of circular apertures and slits at arbitrary distances z from either side of the aperture (down to z = ± 0.0003 λ) are presented, and numerical examples of the results are given. These results show that the incident geometrical field is modulated by diffraction before it reaches the aperture plane while the reflected field is spilled into the dark space. At distances from the aperture which are large compared to the wavelength λ these field expressions are reduced

  10. Coherent x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Pitney, John Allen

    Conventional x-ray diffraction has historically been done under conditions such that the measured signal consists of an incoherent addition of scattering which is coherent only on a length scale determined by the properties of the beam. The result of the incoherent summation is a statistical averaging over the whole illuminated volume of the sample, which yields certain kinds of information with a high degree of precision and has been key to the success of x-ray diffraction in a variety of applications. Coherent x-ray scattering techniques, such as coherent x-ray diffraction (CXD) and x-ray intensity fluctuation spectroscopy (XIFS), attempt to reduce or eliminate any incoherent averaging so that specific, local structures couple to the measurement without being averaged out. In the case of XIFS, the result is analogous to dynamical light scattering, but with sensitivity to length scales less than 200 nm and time scales from 10-3 s to 103 s. When combined with phase retrieval, CXD represents an imaging technique with the penetration, in situ capabilities, and contrast mechanisms associated with x-rays and with a spatial resolution ultimately limited by the x-ray wavelength. In practice, however, the spatial resolution of CXD imaging is limited by exposure to about 100 A. This thesis describes CXD measurements of the binary alloy Cu3Au and the adaptation of phase retrieval methods for the reconstruction of real-space images of Cu3Au antiphase domains. The theoretical foundations of CXD are described in Chapter 1 as derived from the kinematical formulation for x-ray diffraction and from the temporal and spatial coherence of radiation. The antiphase domain structure of Cu 3Au is described, along with the associated reciprocal-space structure which is measured by CXD. CXD measurements place relatively stringent requirements on the coherence properties of the beam and on the detection mechanism of the experiment; these requirements and the means by which they have been

  11. Fiber optic diffraction grating maker

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1991-05-21

    A compact and portable diffraction grating maker is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent beam splitters, and collimating lenses or mirrors directing the split beam at an appropriate photosensitive material. The collimating optics, the output ends of the fiber optic coupler and the photosensitive plate holder are all mounted on an articulated framework so that the angle of intersection of the beams can be altered at will without disturbing the spatial filter, collimation or beam quality, and assuring that the beams will always intersect at the position of the plate. 4 figures.

  12. Fiber optic diffraction grating maker

    DOEpatents

    Deason, Vance A.; Ward, Michael B.

    1991-01-01

    A compact and portable diffraction grating maker comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent beam splitters, and collimating lenses or mirrors directing the split beam at an appropriate photosensitive material. The collimating optics, the output ends of the fiber optic coupler and the photosensitive plate holder are all mounted on an articulated framework so that the angle of intersection of the beams can be altered at will without disturbing the spatial filter, collimation or beam quality, and assuring that the beams will always intersect at the position of the plate.

  13. DIFFRACTION DISSOCIATION - 50 YEARS LATER.

    SciTech Connect

    WHITE, S.N.

    2005-04-27

    The field of Diffraction Dissociation, which is the subject of this workshop, began 50 years ago with the analysis of deuteron stripping in low energy collisions with nuclei. We return to the subject in a modern context- deuteron dissociation in {radical}s{sub NN} = 200 GeV d-Au collisions recorded during the 2003 RHIC run in the PHENIX experiment. At RHIC energy, d {yields} n+p proceeds predominantly (90%) through Electromagnetic Dissociation and the remaining fraction via the hadronic shadowing described by Glauber. Since the dissociation cross section has a small theoretical error we adopt this process to normalize other cross sections measured in RHIC.

  14. Micron-Accurate Laser Fresnel-Diffraction Ranging System

    NASA Technical Reports Server (NTRS)

    Lehner, David; Campbell, Jonathan; Smith, Kelly; Sanders, Alvin; Allison, Stephen; Smaley, Larry

    2008-01-01

    Two versions of an optoelectronic system undergoing development are depicted. The system is expected to be capable of measuring a distance between 2 and 10 m with an error of no more than 1 micrometer. The system would be designed to exploit Fresnel diffraction of a laser beam. In particular, it would be designed to take advantage of the fact that a Fresnel diffraction pattern is ultrasensitive to distance. The two versions would differ in the following respects: In version 1, the focus of the telescope would be in the Fresnel region, and the telescope would have a small depth of focus. As a consequence, the Fresnel pattern would be imaged directly onto the photodetector array; in version 2, a multielement lens module would displace the Fresnel region from the vicinity of the pinhole to the vicinity of the optical receiver. As the distance to be measured varied, the location of the receiver relative to the displaced Fresnel-diffraction region would vary, thereby causing the Fresnel diffraction pattern on the focal plane to vary. The multielement lens module would also correct for aberrations. The processing of the digitized Fresnel diffraction pattern in the computer might be accelerated by using only parts of the pattern or even only one small part - the central pixel. As the distance from the pinhole increased, the central pixel would rapidly cycle between maximum and minimum light intensity. This in itself would not be sufficient to uniquely determine the distance. However, by varying the size of the pinhole or the wavelength of the laser, one could obtain a second cycle of variation of intensity that, in conjunction with the first cycle, could enable a unique determination of distance. Alternatively, for a single wavelength and a single pinhole size, it should suffice to consider the data from only two different key pixels in the Fresnel pattern.

  15. Undergraduate Experiment with Fractal Diffraction Gratings

    ERIC Educational Resources Information Center

    Monsoriu, Juan A.; Furlan, Walter D.; Pons, Amparo; Barreiro, Juan C.; Gimenez, Marcos H.

    2011-01-01

    We present a simple diffraction experiment with fractal gratings based on the triadic Cantor set. Diffraction by fractals is proposed as a motivating strategy for students of optics in the potential applications of optical processing. Fraunhofer diffraction patterns are obtained using standard equipment present in most undergraduate physics…

  16. Undergraduate Experiment with Fractal Diffraction Gratings

    ERIC Educational Resources Information Center

    Monsoriu, Juan A.; Furlan, Walter D.; Pons, Amparo; Barreiro, Juan C.; Gimenez, Marcos H.

    2011-01-01

    We present a simple diffraction experiment with fractal gratings based on the triadic Cantor set. Diffraction by fractals is proposed as a motivating strategy for students of optics in the potential applications of optical processing. Fraunhofer diffraction patterns are obtained using standard equipment present in most undergraduate physics…

  17. Ultrafast electron diffraction from aligned molecules

    SciTech Connect

    Centurion, Martin

    2015-08-17

    The aim of this project was to record time-resolved electron diffraction patterns of aligned molecules and to reconstruct the 3D molecular structure. The molecules are aligned non-adiabatically using a femtosecond laser pulse. A femtosecond electron pulse then records a diffraction pattern while the molecules are aligned. The diffraction patterns are then be processed to obtain the molecular structure.

  18. Diffractive molecular-orbital tomography

    NASA Astrophysics Data System (ADS)

    Zhai, Chunyang; Zhu, Xiaosong; Lan, Pengfei; Wang, Feng; He, Lixin; Shi, Wenjing; Li, Yang; Li, Min; Zhang, Qingbin; Lu, Peixiang

    2017-03-01

    High-order-harmonic generation in the interaction of femtosecond lasers with atoms and molecules opens the path to molecular-orbital tomography and to probe the electronic dynamics with attosecond-Ångström resolutions. Molecular-orbital tomography requires both the amplitude and phase of the high-order harmonics. Yet the measurement of phases requires sophisticated techniques and represents formidable challenges at present. Here we report a scheme, called diffractive molecular-orbital tomography, to retrieve the molecular orbital solely from the amplitude of high-order harmonics without measuring any phase information. We have applied this method to image the molecular orbitals of N2, CO2, and C2H2 . The retrieved orbital is further improved by taking account the correction of Coulomb potential. The diffractive molecular-orbital tomography scheme, removing the roadblock of phase measurement, significantly simplifies the molecular-orbital tomography procedure and paves an efficient and robust way to the imaging of more complex molecules.

  19. Flatland optics. III. Achromatic diffraction.

    PubMed

    Lohmann, A W; Pe'er, A; Wang, D; Friesem, A A

    2001-09-01

    In the previous two sections of "Flatland optics" [J. Opt. Soc. Am. A 17, 1755 (2000); 18, 1056 (2001)] we described the basic principles of two-dimensional (2D) optics and showed that a wavelength lambda in three-dimensional (3D) space (x, y, z) may appear in Flatland (x, z) as a wave with another wavelength Lambda=lambda/cos alpha. The tilt angle alpha can be modified by a 3D-Spaceland individual, who then is able to influence the 2D optics in a way that must appear to be magical to 2D-Flatland individuals-in the spirit of E. A. Abbott's science fiction story of 1884 [Flatland, a Romance of Many Dimensions, 6th ed. (Dover, New York, 1952)]. Here we show how the light from a white source can be perceived in Flatland as perfectly monochromatic, so diffraction with white light will be free of color blurring and the contrast of interference fringes can be 100%. The basic considerations for perfectly achromatic diffraction are presented, along with experimental illustration of Talbot self-imaging performed with broadband illumination.

  20. Diffraction optics for terahertz waves

    NASA Astrophysics Data System (ADS)

    Wiltse, James C.

    2004-09-01

    Conventional lenses are important components for many terahertz applications, but ordinary lenses are very difficult to fabricate for short-focal lengths. Multi-level phase-corrected zoned lens antennas have been investigated with particular application at terahertz wavelengths. These zoned lenses (or diffractive optics) give better performance than ordinary lenses, and because of their planar construction are easier and cheaper to fabricate. The depths of cut needed for a grooved zone plate are quite small, even when materials with low dielectric constants are used. Zoned lenses have been built and tested at various frequencies from 100 GHz to 1.5 THz, with phase correction levels of half-wave, quarter-wave, or eighth-wavelength. The inherent losses in transparent materials increase monotonically over this frequency range. Typical low-loss materials include polystyrene, polyethylene, Teflon, polycarbonate, polystyrene foam, foamed polyethylene, low density polytetrafluoroethylene (PTFE), TPX, quartz, sapphire, and silicon. Low dielectric-constant materials are normally preferred to reduce reflection and attenuation losses. Techniques for cutting or milling the materials to small dimensions are important, because at 1.0 THz an eighth-wavelength correction for silicon is only 15 μm. Another characteristic of zoned diffraction optics is their frequency behavior. Previous investigations have considered their bandwidth dependence and quasi-periodic extended frequency response for a specified focal length. As frequency changes, the focal point moves along the axis of the zoned lens. An analysis is given to explain this effect.

  1. Spectral partitioning in diffraction tomography

    SciTech Connect

    Lehman, S K; Chambers, D H; Candy, J V

    1999-06-14

    The scattering mechanism of diffraction tomography is described by the integral form of the Helmholtz equation. The goal of diffraction tomography is to invert this equation in order to reconstruct the object function from the measured scattered fields. During the forward propagation process, the spatial spectrum of the object under investigation is ''smeared,'' by a convolution in the spectral domain, across the propagating and evanescent regions of the received field. Hence, care must be taken in performing the reconstruction, as the object's spectral information has been moved into regions where it may be considered to be noise rather than useful information. This will reduce the quality and resolution of the reconstruction. We show haw the object's spectrum can be partitioned into resolvable and non-resolvable parts based upon the cutoff between the propagating and evanescent fields. Operating under the Born approximation, we develop a beam-forming on transmit approach to direct the energy into either the propagating or evanescent parts of the spectrum. In this manner, we may individually interrogate the propagating and evanescent regions of the object spectrum.

  2. Instrumentation for Laue diffraction (invited)

    NASA Astrophysics Data System (ADS)

    Helliwell, J. R.; Harrop, S.; Habash, J.; Magorrian, B. G.; Allinson, N. M.; Gomez, D.; Helliwell, M.; Derewenda, Z.; Cruickshank, D. W. J.

    1989-07-01

    Single-crystal x-ray diffraction data can be measured very quickly in Laue geometry compared with monochromatic methods. Alternatively, this gain factor can be used instead to reduce the sample volume for a fixed exposure time. In the latter case especially, there is a critical need to control parasitic scatter in the Laue camera. The use of Laue geometry as a means of quantitative data acquisition required the solution of some fundamental problems. The so-called ``overlapping orders problem'' has been found not to be limiting. It can be shown that the bulk of the Laue spots are single order, provided dhkl<2dmin where dhkl is the interplanar spacing and dmin is the resolution limit of the data. In addition, empirical wavelength normalization is required. This can be achieved by using the symmetry of the diffraction pattern. The fact that different equivalents occur at different wavelengths means that the differences in these intensities can be used to establish the ``λ curve.'' Successful wavelength normalization to date has used a relatively broad-band pass. The multiplicity distribution is the histogram of the number of spots of a given order. This distribution is determined by the ratio λmax/λmin (λmax =maximum wavelength, λmin =minimum wavelength in the beam). λmax is determined by the use of any filters in the beamline. λmin is determined either by the spectral curve or a critical cutoff if a mirror is used. A mirror can be usefully introduced to enhance the multiplicity distribution in favor of single wavelength spots or to focus the white beam; so far only vertical focussing has been used. The detector options used to date have been photographic film, Fuji image plate (at Photon Factory)/Kodak storage phosphor (at Cornell) and charge coupled device (CCD) (at Daresbury). It is useful to consider the joint theoretical spatial and energy distribution of spots in defining the detector specification and geometry. To date, we have processed Laue film data

  3. Heavy-ion dosimetry

    SciTech Connect

    Schimmerling, W.

    1980-03-01

    This lecture deals with some of the more important physical characteristics of relativistic heavy ions and their measurement, with beam delivery and beam monitoring, and with conventional radiation dosimetry as used in the operation of the BEVALAC biomedical facility for high energy heavy ions (Lyman and Howard, 1977; BEVALAC, 1977). Even so, many fundamental aspects of the interaction of relativistic heavy ions with matter, including important atomic physics and radiation chemical considerations, are not discussed beyond the reminder that such additional understanding is required before an adequte perspective of the problem can be attained.

  4. Calculation of Loudspeaker Cabinet Diffraction and Correction

    NASA Astrophysics Data System (ADS)

    Le, Yi; Shen, Yong; Xia, Jie

    2011-10-01

    A method of calculating the cabinet edge diffractions for loudspeaker driver when mounted in an enclosure is proposed, based on the extended Biot—Tolstoy—Medwin model. Up to the third order, cabinet diffractions are discussed in detail and the diffractive effects on the radiated sound field of the loudspeaker system are quantitatively described, with a correction function built to compensate for the diffractive interference. The method is applied to a practical loudspeaker enclosure that has rectangular facets. The diffractive effects of the cabinet on the forward sound radiation are investigated and predictions of the calculations show quite good agreements with experimental measurements.

  5. Near-field diffraction of chirped gratings.

    PubMed

    Sanchez-Brea, Luis Miguel; Torcal-Milla, Francisco Jose; Morlanes, Tomas

    2016-09-01

    In this Letter, we analyze the near-field diffraction pattern produced by chirped gratings. An intuitive analytical interpretation of the generated diffraction orders is proposed. Several interesting properties of the near-field diffraction pattern can be determined, such as the period of the fringes and its visibility. Diffraction orders present different widths and also, some of them present focusing properties. The width, location, and depth of focus of the converging diffraction orders are also determined. The analytical expressions are compared to numerical simulation and experimental results, showing a high agreement.

  6. Heavy Menstrual Bleeding

    MedlinePlus

    ... to pregnancy, such as ectopic pregnancy and miscarriage . Pelvic inflammatory disease also can cause heavy menstrual bleeding. Sometimes, the ... A physical examination of a woman’s reproductive organs. Pelvic Inflammatory Disease: An infection of the uterus, fallopian tubes, and ...

  7. Heavy fermion quantum criticality.

    PubMed

    Nazario, Zaira; Santiago, David I

    2008-09-26

    During the last few years, investigations of rare-earth materials have made clear that heavy fermion quantum criticality exhibits novel physics not fully understood. In this work, we write for the first time the effective action describing the low energy physics of the system. The f fermions are replaced by a dynamical scalar field whose nonzero expected value corresponds to the heavy fermion phase. The effective theory is amenable to numerical studies as it is bosonic, circumventing the fermion sign problem. Via effective action techniques, renormalization group studies, and Callan-Symanzik resummations, we describe the heavy fermion criticality and predict the heavy fermion critical dynamical susceptibility and critical specific heat. The specific heat coefficient exponent we obtain (0.39) is in excellent agreement with the experimental result at low temperatures (0.4).

  8. ESB Heavy Lift Requirements

    DTIC Science & Technology

    2006-01-01

    capacity, cross-country travel ability, and redundancy than the three axles and twelve tires found on the M870 trailer.13,14 In fact, this...equates to an organic ability to move approximately twenty- three percent of the battalion’s heavy equipment that requires prime movers in one lift...Truck Tractor manufactured by Oshkosh Truck Corporation and the M1000 Heavy Equipment Transporter semi-trailer manufactured by Systems

  9. Small angle detectors for study diffractive processes with CMS

    SciTech Connect

    Albrow, M.; Bell, A. J.; d'Enterria, D.; Hall-Wilton, R.; Los, S.; Mokhov, N.; Murray, M.; Penzo, A.; Popescu, S.; Ronzhin, A.; Samoylenko, V. D.; Sobol, A.; Veres, G.

    2014-10-22

    The approach and detectors for diffractive physics based on two current projects—Forward Shower Counter (FSC) and Proton Precision Spectrometer (PPS) are presented. FSC system consists of six (3+3) Stations of scintillator counters, which surround closely the beam pipes along 59 m < |z| < 140 m from IP5 on both plus (+) and minus (-) sides. These will detect showers from very forward particles with rapidity 7.5 < |η| < 10 interacting in the beam pipe and surrounding material. FSC allow measurements of single diffraction: p+p → p+G+X (where G is rapidity gap) for lower masses and double diffraction p+p → X+G+X with a large central rapidity gap. The counters can also be used for beam real-time monitoring and will make an invaluable contribution to the understanding of the background environment and its topology. PPS is designed for study the central exclusive production pp → p+X+p, where the + signs denote the absence of hadronic activity (that is, the presence of a rapidity gap) between the outgoing protons and the decay products of the central system X. The precise measurement of the kinematical parameters of the outgoing protons enables to study the properties of the central state X. In PPS part we consider the detector for high precision timing of these protons—QUARTIC. It consists of L-shape bars with quartz or sapphire radiator. The time resolution of the QUARTIC prototypes achieved ≈ 10 ps.

  10. Diffractive X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes, using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution many orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the super-massive black holes in the center of active galaxies. What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  11. Process for removing heavy metal compounds from heavy crude oil

    DOEpatents

    Cha, Chang Y.; Boysen, John E.; Branthaver, Jan F.

    1991-01-01

    A process is provided for removing heavy metal compounds from heavy crude oil by mixing the heavy crude oil with tar sand; preheating the mixture to a temperature of about 650.degree. F.; heating said mixture to up to 800.degree. F.; and separating tar sand from the light oils formed during said heating. The heavy metals removed from the heavy oils can be recovered from the spent sand for other uses.

  12. Insights into photosystem II from isomorphous difference Fourier maps of femtosecond X-ray diffraction data and quantum mechanics/molecular mechanics structural models

    DOE PAGES

    Wang, Jimin; Askerka, Mikhail; Brudvig, Gary W.; ...

    2017-01-12

    Understanding structure–function relations in photosystem II (PSII) is important for the development of biomimetic photocatalytic systems. X-ray crystallography, computational modeling, and spectroscopy have played central roles in elucidating the structure and function of PSII. Recent breakthroughs in femtosecond X-ray crystallography offer the possibility of collecting diffraction data from the X-ray free electron laser (XFEL) before radiation damage of the sample, thereby overcoming the main challenge of conventional X-ray diffraction methods. However, the interpretation of XFEL data from PSII intermediates is challenging because of the issues regarding data-processing, uncertainty on the precise positions of light oxygen atoms next to heavy metalmore » centers, and different kinetics of the S-state transition in microcrystals compared to solution. Lastly, we summarize recent advances and outstanding challenges in PSII structure–function determination with emphasis on the implementation of quantum mechanics/molecular mechanics techniques combined with isomorphous difference Fourier maps, direct methods, and high-resolution spectroscopy.« less

  13. Insights into Photosystem II from Isomorphous Difference Fourier Maps of Femtosecond X-ray Diffraction Data and Quantum Mechanics/Molecular Mechanics Structural Models.

    PubMed

    Wang, Jimin; Askerka, Mikhail; Brudvig, Gary W; Batista, Victor S

    2017-02-10

    Understanding structure-function relations in photosystem II (PSII) is important for the development of biomimetic photocatalytic systems. X-ray crystallography, computational modeling, and spectroscopy have played central roles in elucidating the structure and function of PSII. Recent breakthroughs in femtosecond X-ray crystallography offer the possibility of collecting diffraction data from the X-ray free electron laser (XFEL) before radiation damage of the sample, thereby overcoming the main challenge of conventional X-ray diffraction methods. However, the interpretation of XFEL data from PSII intermediates is challenging because of the issues regarding data-processing, uncertainty on the precise positions of light oxygen atoms next to heavy metal centers, and different kinetics of the S-state transition in microcrystals compared to solution. Here, we summarize recent advances and outstanding challenges in PSII structure-function determination with emphasis on the implementation of quantum mechanics/molecular mechanics techniques combined with isomorphous difference Fourier maps, direct methods, and high-resolution spectroscopy.

  14. Insights into Photosystem II from Isomorphous Difference Fourier Maps of Femtosecond X-ray Diffraction Data and Quantum Mechanics/Molecular Mechanics Structural Models

    PubMed Central

    2017-01-01

    Understanding structure–function relations in photosystem II (PSII) is important for the development of biomimetic photocatalytic systems. X-ray crystallography, computational modeling, and spectroscopy have played central roles in elucidating the structure and function of PSII. Recent breakthroughs in femtosecond X-ray crystallography offer the possibility of collecting diffraction data from the X-ray free electron laser (XFEL) before radiation damage of the sample, thereby overcoming the main challenge of conventional X-ray diffraction methods. However, the interpretation of XFEL data from PSII intermediates is challenging because of the issues regarding data-processing, uncertainty on the precise positions of light oxygen atoms next to heavy metal centers, and different kinetics of the S-state transition in microcrystals compared to solution. Here, we summarize recent advances and outstanding challenges in PSII structure–function determination with emphasis on the implementation of quantum mechanics/molecular mechanics techniques combined with isomorphous difference Fourier maps, direct methods, and high-resolution spectroscopy. PMID:28217747

  15. Generation of diffraction-free plasmonic beams with one-dimensional Bessel profiles.

    PubMed

    Garcia-Ortiz, Cesar E; Coello, Victor; Han, Zhanghua; Bozhevolnyi, Sergey I

    2013-03-15

    We demonstrate experimentally generation of diffraction-free plasmonic beams with zeroth- and first-order Bessel intensity profiles using axicon-like structures fabricated on gold film surfaces and designed to operate at a wavelength of 700 nm. The central beam features a very low divergence (~8π mrad) for a narrow waist of the order of one wavelength and the ability to self reconstruct, which are the main signatures of diffraction-free beams.

  16. Image contrast of diffraction-limited telescopes for circular incoherent sources of uniform radiance

    NASA Technical Reports Server (NTRS)

    Shackleford, W. L.

    1980-01-01

    A simple approximate formula is derived for the background intensity beyond the edge of the image of uniform incoherent circular light source relative to the irradiance near the center of the image. The analysis applies to diffraction-limited telescopes with or without central beam obscuration due to a secondary mirror. Scattering off optical surfaces is neglected. The analysis is expected to be most applicable to spaceborne IR telescopes, for which diffraction can be the major source of off-axis response.

  17. Measurements of identified particle spectra in diffractive pp collisions with the STAR detector at RHIC

    NASA Astrophysics Data System (ADS)

    Fulek, Łukasz

    2017-03-01

    We present the diffractive program with the STAR Roman Pot detectors at RHIC, focusing on the spectra of identified charged particles as pions, kaons and protons and their anti-particle counterparts in Single Diffraction (p + p → p + X) and Central Diffraction (p + p → p + X + p) processes. Moreover, the p ¯/p ratio as a function of rapidity is presented to study the baryon number transfer from forward to midrapidity in Single Diffraction. Similar effect has been studied in proton-proton and proton-photon interactions but it is the first measurement in proton-Pomeron interaction. The forward proton(s) were tagged in the STAR Roman Pot system while the identified charged particle tracks were reconstructed in the STAR Time Projection Chamber (TPC). Ionization energy loss and time-of-flight of charged particles were used for particle identification. In addition, the status and future prospects of the diffractive meaurements at RHIC is described.

  18. Pre-equilibrium decay processes in energetic heavy ion reactions

    SciTech Connect

    Blann, M.

    1986-04-15

    The Boltzmann master equation (BME) is defined for application to precompound decay in heavy ion reactions in the 10 100 MeV/nucleon regime. Predicted neutron spectra are compared with measured results for central collisions of /sup 20/Ne and /sup 12/C with /sup 165/Ho target nuclei. Comparisons are made with subthreshold ..pi../sup 0/ yields in heavy ion reactions between 35 and 84 MeV/nucleon, and with the ..pi../sup 0/ spectra. The BME is found to be an excellent tool for investigating these experimentally observed aspects of non-equilibrium heavy ion reactions. 18 refs., 8 figs.

  19. Spectral methods in edge-diffraction theories

    SciTech Connect

    Arnold, J.M. )

    1992-12-01

    Spectral methods for the construction of uniform asymptotic representations of the field diffracted by an aperture in a plane screen are reviewed. These are separated into contrasting approaches, roughly described as physical and geometrical. It is concluded that the geometrical methods provide a direct route to the construction of uniform representations that are formally identical to the equivalent-edge-current concept. Some interpretive and analytical difficulties that complicate the physical methods of obtaining uniform representations are analyzed. Spectral synthesis proceeds directly from the ray geometry and diffraction coefficients, without any intervening current representation, and the representation is uniform at shadow boundaries and caustics of the diffracted field. The physical theory of diffraction postulates currents on the diffracting screen that give rise to the diffracted field. The difficulties encountered in evaluating the current integrals are throughly examined, and it is concluded that the additional data provided by the physical theory of diffraction (diffraction coefficients off the Keller diffraction cone) are not actually required for obtaining uniform asymptotics at the leading order. A new diffraction representation that generalizes to arbitrary plane-convex apertures a formula given by Knott and Senior [Proc. IEEE 62, 1468 (1974)] for circular apertures is deduced. 34 refs., 1 fig.

  20. Bragg's Law diffraction simulations for electron backscatter diffraction analysis.

    PubMed

    Kacher, Josh; Landon, Colin; Adams, Brent L; Fullwood, David

    2009-08-01

    In 2006, Angus Wilkinson introduced a cross-correlation-based electron backscatter diffraction (EBSD) texture analysis system capable of measuring lattice rotations and elastic strains to high resolution. A variation of the cross-correlation method is introduced using Bragg's Law-based simulated EBSD patterns as strain free reference patterns that facilitates the use of the cross-correlation method with polycrystalline materials. The lattice state is found by comparing simulated patterns to collected patterns at a number of regions on the pattern using the cross-correlation function and calculating the deformation from the measured shifts of each region. A new pattern can be simulated at the deformed state, and the process can be iterated a number of times to converge on the absolute lattice state. By analyzing an iteratively rotated single crystal silicon sample and recovering the rotation, this method is shown to have an angular resolution of approximately 0.04 degrees and an elastic strain resolution of approximately 7e-4. As an example of applications, elastic strain and curvature measurements are used to estimate the dislocation density in a single grain of a compressed polycrystalline Mg-based AZ91 alloy.

  1. Human eye visual hyperacuity: Controlled diffraction for image resolution improvement

    NASA Astrophysics Data System (ADS)

    Lagunas, A.; Domínguez, O.; Martinez-Conde, S.; Macknik, S. L.; Del-Río, C.

    2017-09-01

    The Human Visual System appears to be using a low number of sensors for image capturing, and furthermore, regarding the physical dimensions of cones—photoreceptors responsible for the sharp central vision—we may realize that these sensors are of a relatively small size and area. Nonetheless, the human eye is capable of resolving fine details thanks to visual hyperacuity and presents an impressive sensitivity and dynamic range when set against conventional digital cameras of similar characteristics. This article is based on the hypothesis that the human eye may be benefiting from diffraction to improve both image resolution and acquisition process. The developed method involves the introduction of a controlled diffraction pattern at an initial stage that enables the use of a limited number of sensors for capturing the image and makes possible a subsequent post-processing to improve the final image resolution.

  2. Space charge effects in ultrafast electron diffraction and imaging

    NASA Astrophysics Data System (ADS)

    Tao, Zhensheng; Zhang, He; Duxbury, P. M.; Berz, Martin; Ruan, Chong-Yu

    2012-02-01

    Understanding space charge effects is central for the development of high-brightness ultrafast electron diffraction and microscopy techniques for imaging material transformation with atomic scale detail at the fs to ps timescales. We present methods and results for direct ultrafast photoelectron beam characterization employing a shadow projection imaging technique to investigate the generation of ultrafast, non-uniform, intense photoelectron pulses in a dc photo-gun geometry. Combined with N-particle simulations and an analytical Gaussian model, we elucidate three essential space-charge-led features: the pulse lengthening following a power-law scaling, the broadening of the initial energy distribution, and the virtual cathode threshold. The impacts of these space charge effects on the performance of the next generation high-brightness ultrafast electron diffraction and imaging systems are evaluated.

  3. Removal of heavy metals using waste eggshell.

    PubMed

    Park, Heung Jai; Jeong, Seong Wook; Yang, Jae Kyu; Kim, Boo Gil; Lee, Seung Mok

    2007-01-01

    The removal capacity of toxic heavy metals by the reused eggshell was studied. As a pretreatment process for the preparation of reused material from waste eggshell, calcination was performed in the furnace at 800 degrees C for 2 h after crushing the dried waste eggshell. Calcination behavior, qualitative and quantitative elemental information, mineral type and surface characteristics before and after calcination of eggshell were examined by thermal gravimetric analysis (TGA), X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. After calcination, the major inorganic composition was identified as Ca (lime, 99.63%) and K, P and Sr were identified as minor components. When calcined eggshell was applied in the treatment of synthetic wastewater containing heavy metals, a complete removal of Cd as well as above 99% removal of Cr was observed after 10 min. Although the natural eggshell had some removal capacity of Cd and Cr, a complete removal was not accomplished even after 60 min due to quite slower removal rate. However, in contrast to Cd and Cr, an efficient removal of Pb was observed with the natural eggshell rather than the calcined eggshell. From the application of the calcined eggshell in the treatment of real electroplating wastewater, the calcined eggshell showed a promising removal capacity of heavy metal ions as well as had a good neutralization capacity in the treatment of strong acidic wastewater.

  4. Diffraction Correlation to Reconstruct Highly Strained Particles

    NASA Astrophysics Data System (ADS)

    Brown, Douglas; Harder, Ross; Clark, Jesse; Kim, J. W.; Kiefer, Boris; Fullerton, Eric; Shpyrko, Oleg; Fohtung, Edwin

    2015-03-01

    Through the use of coherent x-ray diffraction a three-dimensional diffraction pattern of a highly strained nano-crystal can be recorded in reciprocal space by a detector. Only the intensities are recorded, resulting in a loss of the complex phase. The recorded diffraction pattern therefore requires computational processing to reconstruct the density and complex distribution of the diffracted nano-crystal. For highly strained crystals, standard methods using HIO and ER algorithms are no longer sufficient to reconstruct the diffraction pattern. Our solution is to correlate the symmetry in reciprocal space to generate an a priori shape constraint to guide the computational reconstruction of the diffraction pattern. This approach has improved the ability to accurately reconstruct highly strained nano-crystals.

  5. Anomalous Diffraction in Crystallographic Phase Evaluation

    PubMed Central

    Hendrickson, Wayne A.

    2014-01-01

    X-ray diffraction patterns from crystals of biological macromolecules contain sufficient information to define atomic structures, but atomic positions are inextricable without having electron-density images. Diffraction measurements provide amplitudes, but the computation of electron density also requires phases for the diffracted waves. The resonance phenomenon known as anomalous scattering offers a powerful solution to this phase problem. Exploiting scattering resonances from diverse elements, the methods of multiwavelength anomalous diffraction (MAD) and single-wavelength anomalous diffraction (SAD) now predominate for de novo determinations of atomic-level biological structures. This review describes the physical underpinnings of anomalous diffraction methods, the evolution of these methods to their current maturity, the elements, procedures and instrumentation used for effective implementation, and the realm of applications. PMID:24726017

  6. Optimizing Crystal Volume for Neutron Diffraction

    NASA Technical Reports Server (NTRS)

    Snell, Edward H.; vanderWoerd, Mark; Damon, Michael; Judge, Russell, A.; Myles, Dean; Meilleur, F.

    2006-01-01

    Neutron diffraction is uniquely sensitive to hydrogen positions and protonation state. In that context structural information from neutron data is complementary to that provided through X-ray diffraction. However, there are practical obstacles to overcome in fully exploiting the potential of neutron diffraction, Le. low flux and weak scattering. Several approaches are available to overcome these obstacles and we have investigated the simplest: increasing the diffracting volume of the crystals. Volume is a quantifiable metric that is well suited for experiment design and optimization techniques. By using response surface methods we have optimized xylose isomerase crystal volume, enabling neutron diffraction while we determined the crystallization parameters with the minimum of experiments. Our results suggest a systematic means of enabling neutron diffraction studies for a larger number of samples that require information on hydrogen position and/or protonation state.

  7. Single Hit Energy-resolved Laue Diffraction

    NASA Astrophysics Data System (ADS)

    Patel, Shamim; Suggit, Matthew; Stubley, Paul; Hawreliak, James; Ciricosta, Orlando; Comley, Andrew; Collins, Gilbert; Eggert, Jon; Foster, John; Wark, Justin; Higginbotham, Andrew

    2015-06-01

    In-situ white light Laue diffraction is a technique to interrogate the structure of materials undergoing dynamic compression up to megabar pressures. We present an extension to the existing Laue diffraction platform in which CCD cameras are used in single photon mode enabling a measurement of the energy of a subset of diffraction peaks. Careful choice of which diffraction peaks are observed allows for a measurement of the longitudinal and transverse strains. This allows for the measurement of absolute volume of the unit cell in addition to its aspect ratio. We present results for silicon, where only longitudinal elastic strain has been observed. VISAR measurements show the presence of a two wave structure and measurements made from the diffraction patterns on the CCD show that material downstream of the second wave does not contribute to the observed diffraction peaks, suggesting that this material may be highly disordered, or has undergone large scale rotation.

  8. Evaluation of Diffraction by a Rounded Surface

    NASA Technical Reports Server (NTRS)

    Rabin, Douglas M.

    2011-01-01

    Wide-angle heliospheric imagers such as those carried on the SMEI and STEREO spacecraft require highly effective baffle systems to exclude diffracted light from the solar disk as well as other sources of stray light. Buffington (2000, Appl. Opt. 39, 2683-2686) has proposed replacing multi-vane baffle systems with a curved surface that can be thought of as the limiting case of closely spaced vanes. Buffington s experimental data showed that the diffractive performance of a continuous baffle is consistent with the limiting form expected from multi-vane diffraction on dimensional grounds, but a detailed prediction was not possible because multi-vane diffraction calculations assume that the diffractive edges act independently, an assumption that breaks down for a continuous surface. I describe analytic calculations of diffraction from a smooth rounded surface based on the approach of Vogler (1985, Radio Sci. 20, 582-590).

  9. The characteristics of compound diffractive telescope.

    PubMed

    Liu, Hua; Lu, Zhenwu; Yue, Jinying; Zhang, Honxin

    2008-09-29

    Compound diffractive telescope is a new type of space optical system. It applies the structure of compound eyes into diffractive telescopes. With the help of diffractive optical element, the optical system could become lighter in weight, lower in cost, and looser in sensitivity to manufacturing tolerance. And with the help of compound eyes structure, the field of view is expanded. A demonstrated system of compound diffractive telescope is given. It is composed of one 50mm aperture primary diffractive lens and twenty-one eyepieces. The characteristics of the system are analysed by testing its star image and resolution. It is shown that the whole system can provide about diffraction limit imaging within 4.2 degree field of view.

  10. Optimizing Crystal Volume for Neutron Diffraction

    NASA Technical Reports Server (NTRS)

    Snell, Edward H.; vanderWoerd, Mark; Damon, Michael; Judge, Russell, A.; Myles, Dean; Meilleur, F.

    2006-01-01

    Neutron diffraction is uniquely sensitive to hydrogen positions and protonation state. In that context structural information from neutron data is complementary to that provided through X-ray diffraction. However, there are practical obstacles to overcome in fully exploiting the potential of neutron diffraction, Le. low flux and weak scattering. Several approaches are available to overcome these obstacles and we have investigated the simplest: increasing the diffracting volume of the crystals. Volume is a quantifiable metric that is well suited for experiment design and optimization techniques. By using response surface methods we have optimized xylose isomerase crystal volume, enabling neutron diffraction while we determined the crystallization parameters with the minimum of experiments. Our results suggest a systematic means of enabling neutron diffraction studies for a larger number of samples that require information on hydrogen position and/or protonation state.

  11. Diffraction efficiency enhancement of femtosecond laser-engraved diffraction gratings due to CO2 laser polishing

    NASA Astrophysics Data System (ADS)

    Choi, Hun-Kook; Jung, Deok; Sohn, Ik-Bu; Noh, Young-Chul; Lee, Yong-Tak; Kim, Jin-Tae; Ahsan, Md. Shamim

    2014-11-01

    This research demonstrates laser-assisted fabrication of high-efficiency diffraction gratings in fused-silica glass samples. Initially, femtosecond laser pulses are used to engrave diffraction gratings on the glass surfaces. Then, these micro-patterned glass samples undergo CO2 laser polishing process. unpolished diffraction gratings encoded in the glass samples show an overall diffraction efficiency of 18.1%. diffraction gratings imprinted on the glass samples and then polished four times by using a CO2 laser beam attain a diffraction efficiency of 32.7%. We also investigate the diffraction patterns of the diffraction gratings encoded on fused-silica glass surfaces. The proposed CO2 laser polishing technique shows great potential in patterning high-efficiency diffraction gratings on the surfaces of various transparent materials.

  12. Analysis of Diffraction Anomalous Fine Structure

    NASA Astrophysics Data System (ADS)

    Cross, Julie Olmsted

    This thesis presents a systematic study of the application of DAFS to determine site-specific local structural and chemical information in complex materials, and the first application of state-of-the-art theoretical XAFS calculations using the computer program scFEFF to model DAFS data. In addition, the iterative dispersion analysis method, first suggested by Pickering, et al., has been generalized to accommodate the off-resonance anomalous scattering from heavy atoms in the unit cell. The generalized algorithm scKKFIT was applied to DAFS data from eight (00 l) reflections of the high-T _{c} superconductor YBa _2Cu_3O_ {6.8} to obtain the weighted complex resonant scattering amplitudes Delta f_{ rm w}(Q, E). The fine-structure functions chi_{rm w}(Q, E) isolated from the Delta f_{ rm w}(Q, E) are linear combinations of the individual site fine structure functions chi _{rm w}(Q, E) = Sigma_{i}W_{i,{ bf Q}}chi_{i}(E) from the two inequivalent Cu sites, added together according to the structure factor for the Cu sublattice. The chi_{rm w}(Q, E) were fit en masse using the XAFS analysis program scFEFFIT under a set of constraints on the coefficients W _{i,{bf Q}} based on the structure factor for kinematic scattering. The W_{i,{bf Q}} determined by scFEFFIT were used to obtain the fully separated complex resonant scattering amplitudes Delta f(E) for the two Cu sites. The theoretical connection between DAFS and XAFS is used to justify the application of state-of-the-art theoretical XAFS calculations to DAFS analysis. The polarization dependence of DAFS is described in terms of individual virtual photoelectron scattering paths in the Rehr-Albers separable curved-wave formalism. Polarization is shown to be an important factor in all DAFS experiments. Three experimental constraints are found necessary for obtaining site-separated Delta f(E) from DAFS data by linear inversion of the W_{i, {bf Q}} matrix and scKKFIT isolated Delta f_{rm w }(Q, E): (1) The diffraction must be

  13. Heavy-atom derivatization.

    PubMed

    Garman, Elspeth; Murray, James W

    2003-11-01

    Most of the standard methods of solving macromolecular structures involve producing a protein crystal that is derivatized by an anomalous scatterer or heavy atom (MIR, SIRAS, MAD, SAD etc.). The theoretical methodology which underpins the extraction of phase information from such derivatives is widely available in the literature. In addition, there are comprehensive sources of information on the chemistry of heavy-atom compounds and the ligands with which they are known to interact, as well as the Heavy Atom Databank accessible on the World Wide Web. This contribution therefore aims to provide some information on the less well documented practical problems of firstly deciding on an overall strategy for derivatization and secondly performing the physical manipulations involved in producing heavy-atom derivatives from native protein crystals and then cryocooling them. Ways to optimize the chances of isomorphous unit cells are suggested. Methods of determining whether or not the heavy atom is bound are outlined, including the powerful technique of PIXE (particle-induced X-ray emission).

  14. Fraunhofer diffraction of light by human enamel.

    PubMed

    O'Brien, W J

    1988-02-01

    Fraunhofer diffraction patterns of human enamel samples were photographed with a helium-neon laser beam (lambda = 633 nm). The first-order diffraction angle was in reasonable agreement with a prediction based upon enamel prisms acting as a two-dimensional grating. These results support the hypothesis that enamel diffracts light because of the periodic structure of enamel prisms with interprismatic spaces, which act as slits.

  15. Aircraft noise propagation. [sound diffraction by wings

    NASA Technical Reports Server (NTRS)

    Hadden, W. J.; Pierce, A. D.

    1978-01-01

    Sound diffraction experiments conducted at NASA Langley Research Center to study the acoustical implications of the engine over wing configuration (noise-shielding by wing) and to provide a data base for assessing various theoretical approaches to the problem of aircraft noise reduction are described. Topics explored include the theory of sound diffraction around screens and wedges; the scattering of spherical waves by rectangular patches; plane wave diffraction by a wedge with finite impedence; and the effects of ambient flow and distribution sources.

  16. Twenty years of diffraction at the Tevatron

    SciTech Connect

    Goulianos, K.; /Rockefeller U.

    2005-10-01

    Results on diffractive particle interactions from the Fermilab Tevatron {bar p}p collider are placed in perspective through a QCD inspired phenomenological approach, which exploits scaling and factorization properties observed in data. The results discussed are those obtained by the CDF Collaboration from a comprehensive set of single, double, and multigap soft and hard diffraction processes studied during the twenty year period since 1985, when the CDF diffractive program was proposed and the first Blois Workshop was held.

  17. Diffraction gratings used as identifying markers

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1991-03-26

    A finely detailed diffraction grating is applied to an object as an identifier or tag which is unambiguous, difficult to duplicate, or remove and transfer to another item, and can be read and compared with prior readings with relative ease. The exact pattern of the diffraction grating is mapped by diffraction moire techniques and recorded for comparison with future readings of the same grating. 7 figures.

  18. Diffraction Techniques in Steel Research: An Overview

    NASA Astrophysics Data System (ADS)

    Melzer, Stefan; Moerman, Jaap

    Acquiring knowledge about microstructures and textures is crucial for the improvement and development steel products, because these two characteristics are controlling factors for the properties of steel. Diffraction techniques using X-rays, electrons or neutrons are suitable to study microstructures (e.g. phase relationships) and textures (crystallographic orientations). X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) are generally available techniques within an industrial research environment.

  19. CMS results on soft and hard diffraction

    NASA Astrophysics Data System (ADS)

    Obertino, M. M.

    2017-03-01

    The measurement of the soft diffractive cross sections in single- and double-diffractive final states is presented at 7 TeV. Furthermore, the production of jet-gap-jet final states is discussed and the results are interpreted in terms of a hard color singlet exchange. Finally, general features of particle production in single-diffractive enhanced events are shown at 13 TeV.

  20. Structures from Anomalous Diffraction of Native Biological Macromolecules

    PubMed Central

    Liu, Qun; Dahmane, Tassadite; Zhang, Zhen; Assur, Zahra; Brasch, Julia; Shapiro, Lawrence; Mancia, Filippo; Hendrickson, Wayne A.

    2013-01-01

    Crystal structure analyses for biological macromolecules without known structural relatives entail solving the crystallographic phase problem. Typical de novo phase evaluations depend on incorporating heavier atoms than those found natively; most commonly, multi- or single-wavelength anomalous diffraction (MAD or SAD) experiments exploit selenomethionyl proteins. Here we realize routine structure determination using intrinsic anomalous scattering from native macromolecules. We devised robust procedures for enhancing signal-to-noise in the slight anomalous scattering from generic native structures by combining data measured from multiple crystals at lower-than-usual x-ray energy. Using this multi-crystal SAD method (5–13 equivalent crystals), we determined structures at modest resolution (2.8Å-2.3Å) for native proteins varying in size (127–1148 unique residues) and number of sulfur sites (3–28). With no requirement for heavy-atom incorporation, such experiments provide an attractive alternative to selenomethionyl SAD experiments. PMID:22628655

  1. What Phase Matters for Diffraction?

    NASA Astrophysics Data System (ADS)

    Jones, Eric; Bach, Roger; Batelaan, Herman

    2014-05-01

    Young's double-slit experiment for matter is often compared to that of optics. In rudimentary explanations of the locations of the diffraction maxima and minima far from the slits, paths are sometimes superimposed over waves drawn from the two slits to the detection screen, leading to a phase difference of Δϕ = 2 πΔL /λdB between paths. Despite the intuitive connection of the two kinds of wave phenomena, this approach can lead to a misunderstanding of the theory for matter waves. The Feynman path-integral formalism justifies the use of paths to determine the phase difference; however, the phase accumulated along single free-particle paths according to the formalism is not ϕ = 2 πL /λdB , even though the expression for the phase difference is correct. The resulting factor of 2 difference in the single path phase from the intuitive value arises from the particular treatment of time-dependence in interpreting the problem. The nature of this misunderstanding will be discussed, and a possible resolution proposed based on the quantum mechanical principle of indistinguishability: the time duration of all interfering paths must be equal. We gratefully acknowledge support from the NSF.

  2. Large aperture diffractive space telescope

    DOEpatents

    Hyde, Roderick A.

    2001-01-01

    A large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary objective lens functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass "aiming" at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The objective lens includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the objective lens, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets which may be either earth bound or celestial.

  3. Convex Diffraction Grating Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Chrisp, Michael P. (Inventor)

    1999-01-01

    A 1:1 Offner mirror system for imaging off-axis objects is modified by replacing a concave spherical primary mirror that is concentric with a convex secondary mirror with two concave spherical mirrors M1 and M2 of the same or different radii positioned with their respective distances d1 and d2 from a concentric convex spherical diffraction grating having its grooves parallel to the entrance slit of the spectrometer which replaces the convex secondary mirror. By adjusting their distances d1 and d2 and their respective angles of reflection alpha and beta, defined as the respective angles between their incident and reflected rays, all aberrations are corrected without the need to increase the spectrometer size for a given entrance slit size to reduce astigmatism, thus allowing the imaging spectrometer volume to be less for a given application than would be possible with conventional imaging spectrometers and still give excellent spatial and spectral imaging of the slit image spectra over the focal plane.

  4. Observation of diffraction multifocal radiation focusing

    SciTech Connect

    Letfullin, R R; Zayakin, O A

    2001-04-30

    It is shown experimentally that by placing a flat screen with an axial hole in a diffraction field formed by the first open Fresnel zone upon diffraction of a plane electromagnetic wave from a parallel screen with a hole of a larger diameter, one can observe diffraction multifocal focusing of radiation in the near-field zone of the first screen. The diffraction pattern in the near-field zone of the first screen in focal planes represents circular nonlocalised Fresnel bands with a bright narrow peak at the centre, whose intensity is 6 - 10 greater than that of the incident wave. (nonlinear optical phenomena)

  5. Diffraction by m-bonacci gratings

    NASA Astrophysics Data System (ADS)

    Monsoriu, Juan A.; Giménez, Marcos H.; Furlan, Walter D.; Barreiro, Juan C.; Saavedra, Genaro

    2015-11-01

    We present a simple diffraction experiment with m-bonacci gratings as a new interesting generalization of the Fibonacci ones. Diffraction by these non-conventional structures is proposed as a motivational strategy to introduce students to basic research activities. The Fraunhofer diffraction patterns are obtained with the standard equipment present in most undergraduate physics labs and are compared with those obtained with regular periodic gratings. We show that m-bonacci gratings produce discrete Fraunhofer patterns characterized by a set of diffraction peaks which positions are related to the concept of a generalized golden mean. A very good agreement is obtained between experimental and numerical results and the students’ feedback is discussed.

  6. Catastrophe optics of sharp-edge diffraction.

    PubMed

    Borghi, Riccardo

    2016-07-01

    A classical problem of diffraction theory, namely plane wave diffraction by sharp-edge apertures, is here reformulated from the viewpoint of the fairly new subject of catastrophe optics. On using purely geometrical arguments, properly embedded into a wave optics context, uniform analytical estimates of the diffracted wavefield at points close to fold caustics are obtained, within paraxial approximation, in terms of the Airy function and its first derivative. Diffraction from parabolic apertures is proposed to test reliability and accuracy of our theoretical predictions.

  7. Light shifts in atomic Bragg diffraction

    NASA Astrophysics Data System (ADS)

    Giese, E.; Friedrich, A.; Abend, S.; Rasel, E. M.; Schleich, W. P.

    2016-12-01

    Bragg diffraction of an atomic wave packet in a retroreflective geometry with two counterpropagating optical lattices exhibits a light shift induced phase. We show that the temporal shape of the light pulse determines the behavior of this phase shift: In contrast to Raman diffraction, Bragg diffraction with Gaussian pulses leads to a significant suppression of the intrinsic phase shift due to a scaling with the third power of the inverse Doppler frequency. However, for box-shaped laser pulses, the corresponding shift is twice as large as for Raman diffraction. Our results are based on approximate but analytical expressions as well as a numerical integration of the corresponding Schrödinger equation.

  8. Broadband beam shaping with harmonic diffractive optics.

    PubMed

    Singh, Manisha; Tervo, Jani; Turunen, Jari

    2014-09-22

    We consider spatial shaping of broadband (either stationary or pulsed) spatially coherent light, comparing refractive, standard diffractive, and harmonic diffractive (modulo 2πM) elements. Considering frequency-integrated target profiles we show that, contrary to common belief, standard diffractive (M = 1) elements work reasonably well for, e.g., Gaussian femtosecond pulses and spatially coherent amplified-spontaneous-emission sources such as superluminescent diodes. It is also shown that harmonic elements with M ≥ 5 behave in essentially the same way as refractive elements and clearly outperform standard diffractive elements for highly broadband light.

  9. Diffractively corrected counter-rotating Risley prisms.

    PubMed

    Nie, Xin; Yang, Hongfang; Xue, Changxi

    2015-12-10

    Using the vector refraction equation and the vector diffraction equation, we obtain the expressions of the direction cosines of the refractive rays for the two wedge prisms, and the direction cosines of the diffractive rays for two wedge grisms, in which diffractive gratings were etched into the prism faces to correct the chromatic aberrations. A mathematical model between the two vector equations is proposed to compare the difference angle chromatic aberrations when the Risley prisms/grisms are rotating at different angles. We conclude that the use of diffractively corrected prisms offers a new method to correct chromatic aberrations in Risley prisms.

  10. Optical diffraction microscopy in a teaching laboratory

    NASA Astrophysics Data System (ADS)

    Thibault, Pierre; Rankenburg, Ivan C.

    2007-09-01

    We discuss an optics experiment that reproduces all important aspects of diffraction microscopy or coherent diffractive imaging. This technique is used to reconstruct an object's image from its diffraction pattern. The experimental setup is described in detail and only requires material readily available in a well-equipped optics teaching laboratory. The data analysis procedure is explained, in particular the reconstruction part, for which an iterative phase retrieval algorithm is used. The method is illustrated by showing the complex-valued reconstruction of an insect wing from a diffraction pattern measured with this setup.

  11. Diffractive lenses recorded in absorbent photopolymers.

    PubMed

    Fernández, R; Gallego, S; Márquez, A; Francés, J; Navarro-Fuster, V; Pascual, I

    2016-01-25

    Photopolymers can be appealing materials for diffractive optical elements fabrication. In this paper, we present the recording of diffractive lenses in PVA/AA (Polyvinyl alcohol acrylamide) based photopolymers using a liquid crystal device as a master. In addition, we study the viability of using a diffusion model to simulate the lens formation in the material and to study the influence of the different parameters that govern the diffractive formation in photopolymers. Once we control the influence of each parameter, we can fit an optimum recording schedule to record each different diffractive optical element with the optimum focalization power.

  12. Diffractive Imaging Using Partially Coherent X Rays

    SciTech Connect

    Whitehead, L. W.; Williams, G. J.; Quiney, H. M.; Vine, D. J.; Dilanian, R. A.; Flewett, S.; Nugent, K. A.; Peele, A. G.; Balaur, E.; McNulty, I.

    2009-12-11

    The measured spatial coherence characteristics of the illumination used in a diffractive imaging experiment are incorporated in an algorithm that reconstructs the complex transmission function of an object from experimental x-ray diffraction data using 1.4 keV x rays. Conventional coherent diffractive imaging, which assumes full spatial coherence, is a limiting case of our approach. Even in cases in which the deviation from full spatial coherence is small, we demonstrate a significant improvement in the quality of wave field reconstructions. Our formulation is applicable to x-ray and electron diffraction imaging techniques provided that the spatial coherence properties of the illumination are known or can be measured.

  13. Broadband diffractive lens or imaging element

    DOEpatents

    Ceglio, Natale M.; Hawryluk, Andrew M.; London, Richard A.; Seppala, Lynn G.

    1993-01-01

    A broadband diffractive lens or imaging element produces a sharp focus and/or a high resolution image with broad bandwidth illuminating radiation. The diffractive lens is sectored or segmented into regions, each of which focuses or images a distinct narrowband of radiation but all of which have a common focal length. Alternatively, a serial stack of minus filters, each with a diffraction pattern which focuses or images a distinct narrowband of radiation but all of which have a common focal length, is used. The two approaches can be combined. Multifocal broadband diffractive elements can also be formed. Thin film embodiments are described.

  14. Broadband diffractive lens or imaging element

    DOEpatents

    Ceglio, N.M.; Hawryluk, A.M.; London, R.A.; Seppala, L.G.

    1993-10-26

    A broadband diffractive lens or imaging element produces a sharp focus and/or a high resolution image with broad bandwidth illuminating radiation. The diffractive lens is sectored or segmented into regions, each of which focuses or images a distinct narrowband of radiation but all of which have a common focal length. Alternatively, a serial stack of minus filters, each with a diffraction pattern which focuses or images a distinct narrowband of radiation but all of which have a common focal length, is used. The two approaches can be combined. Multifocal broadband diffractive elements can also be formed. Thin film embodiments are described. 21 figures.

  15. Broadband diffractive lens or imaging element

    DOEpatents

    Ceglio, Natale M.; Hawryluk, Andrew M.; London, Richard A.; Seppala, Lynn G.

    1991-01-01

    A broadband diffractive lens or imaging element produces a sharp focus and/or a high resolution image with broad bandwidth illuminating radiation. The diffractive lens is sectored or segmented into regions, each of which focuses or images a distinct narrowband of radiation but all of which have a common focal length. Alternatively, a serial stack of minus filters, each with a diffraction pattern which focuses or images a distinct narrowband of radiation but all of which have a common focal length, is used. The two approaches can be combined. Multifocal broadband diffractive elements can also be formed.

  16. Heavy quark production in photon-Pomeron interactions at high energies

    SciTech Connect

    Machado, M. M.; Goncalves, V. P.

    2013-03-25

    The diffractive heavy quark cross sections are estimated considering photon-Pomeron interactions in hadron - hadron at RHIC, Tevatron, and CERN LHC energies. We assume the validity of the hard diffractive factorization and calculate the charm and bottom total cross sections and rapidity distributions using the diffractive parton distribution functions of the Pomeron obtained by the H1 Collaboration at DESY-HERA. Such processes are sensitive to the gluon content of the Pomeron at high energies and are a good place to constrain the behavior of this distribution. We also compare our predictions with those obtained using the dipole model, and verify that these processes are a good test of the different mechanisms for heavy quarks diffractive production at hadron colliders.

  17. Heavy exotic molecules

    NASA Astrophysics Data System (ADS)

    Liu, Yizhuang; Zahed, Ismail

    We briefly review the formation of pion-mediated heavy-light exotic molecules with both charm and bottom, under the general structures of chiral and heavy quark symmetries. The charm isosinglet exotic molecules with JPC = 1++ binds, which we identify as the reported neutral X(3872). The bottom isotriplet exotic with JPC = 1+- binds, and is identified as a mixed state of the reported charged exotics Zb+(10610) and Zb+(10650). The bound bottom isosinglet molecule with JPC = 1++ is a possible neutral Xb(10532) to be observed.

  18. Heavy exotic molecules

    NASA Astrophysics Data System (ADS)

    Liu, Yizhuang; Zahed, Ismail

    We briefly review the formation of pion-mediated heavy-light exotic molecules with both charm and bottom, under the general structures of chiral and heavy quark symmetries. The charm isosinglet exotic molecules with JPC = 1++ binds, which we identify as the reported neutral X(3872). The bottom isotriplet exotic with JPC = 1+1 binds, and is identified as a mixed state of the reported charged exotics Zb+(10610) and Zb-(10650). The bound bottom isosinglet molecule with JPC = 1++ is a possible neutral Xb(10532) to be observed.

  19. A new analysis for diffraction correction in optical interferometry

    NASA Astrophysics Data System (ADS)

    Mana, G.; Massa, E.; Sasso, C. P.; Andreas, B.; Kuetgens, U.

    2017-08-01

    Dimensional measurements by laser interferometry require a correction because of diffraction, which makes the fringe period different from the wavelength of a plane wave. The fractional correction—from parts in 10-7 to parts in 10-9, depending on the beam collimation—is half the central second moment of the angular power-spectrum of the beam, a generalization of the divergence concept. We report new insights into the second moment measurement and their consequences on the measurement of the silicon lattice parameter by combined x-ray and optical interferometry.

  20. Holographically formed three-dimensional Penrose-type photonic quasicrystal through a lab-made single diffractive optical element.

    PubMed

    Harb, Ahmad; Torres, Faraon; Ohlinger, Kris; Lin, Yuankun; Lozano, Karen; Xu, Di; Chen, Kevin P

    2010-09-13

    Large-area three-dimensional Penrose-type photonic quasicrystals are fabricated through a holographic lithography method using a lab-made diffractive optical element and a single laser exposure. The diffractive optical element consists of five polymer gratings symmetrically orientated around a central opening. The fabricated Penrose-type photonic quasicrystal shows ten-fold rotational symmetry. The Laue diffraction pattern from the photonic quasi-crystal is observed to be similar to that of the traditional alloy quasi-crystal. A golden ratio of 1.618 is also observed for the radii of diffraction rings, which has not been observed before in artificial photonic quasicrystals.

  1. Central Nucleon-Nucleon Potential

    NASA Astrophysics Data System (ADS)

    Robilotta, M. R.

    2001-12-01

    The outer region of the NN interactions is dominated by the one pion exchange potential (OPEP), followed by the two-pion exchange potential (TPEP). Chiral calculations of the TPEP have been performed using either heavy baryon1 (HB) or relativistic2 perturbation theories. We compare the predictions from these two approaches for the dominant central interaction and show that they fail to agree by 25% ...

  2. The early development of neutron diffraction: Science in the wings of the Manhattan Project

    SciTech Connect

    Mason, Thom; Gawne, Timothy J; Nagler, Stephen E; Nestor, Margaret Boone {Bonnie}; Carpenter, John M

    2012-01-01

    Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurements of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst, and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor.

  3. Latest Results of Open Heavy Flavor and Quarkonia from the PHENIX Experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Nouicer, Rachid; PHENIX Collaboration

    2017-01-01

    The PHENIX Collaboration carries out a comprehensive physics program which studies heavy flavor production in relativistic heavy ion collisions at RHIC. The discovery at RHIC of large high-p T suppression and flow of electrons from heavy quarks flavors have altered our view of the hot and dense matter formed in central Au+Au collisions at GeV. These results suggest a large energy loss and flow of heavy quarks in the hot, dense matter. In recent years, the PHENIX has installed a silicon vertex tracker both in central rapidity (VTX) and in forward rapidity (FVTX) regions, and has collected large data samples. These two silicon trackers enhance the capability of heavy flavor measurements via precision tracking. This paper summarizes some of the latest PHENIX results concerning open heavy flavor and quarkonia production as a function of rapidity, energy and system size.

  4. Calculation of the diffraction efficiency on concave gratings based on Fresnel-Kirchhoff's diffraction formula.

    PubMed

    Huang, Yuanshen; Li, Ting; Xu, Banglian; Hong, Ruijin; Tao, Chunxian; Ling, Jinzhong; Li, Baicheng; Zhang, Dawei; Ni, Zhengji; Zhuang, Songlin

    2013-02-10

    Fraunhofer diffraction formula cannot be applied to calculate the diffraction wave energy distribution of concave gratings like plane gratings because their grooves are distributed on a concave spherical surface. In this paper, a method based on the Kirchhoff diffraction theory is proposed to calculate the diffraction efficiency on concave gratings by considering the curvature of the whole concave spherical surface. According to this approach, each groove surface is divided into several limited small planes, on which the Kirchhoff diffraction field distribution is calculated, and then the diffraction field of whole concave grating can be obtained by superimposition. Formulas to calculate the diffraction efficiency of Rowland-type and flat-field concave gratings are deduced from practical applications. Experimental results showed strong agreement with theoretical computations. With the proposed method, light energy can be optimized to the expected diffraction wave range while implementing aberration-corrected design of concave gratings, particularly for the concave blazed gratings.

  5. RENORM predictions of diffraction at LHC confirmed

    SciTech Connect

    Goulianos, Konstantin

    2015-04-10

    The RENORM model predictions of diffractive, total, and total-inelastic cross sections at the LHC are confirmed by recent measurements. The predictions of several other available models are discussed, highlighting their differences from RENORM, mainly arising from the way rapidity gap formation, low- and high-mass diffraction, unitarization, and hadronization are implemented.

  6. Inquiry with Laser Printer Diffraction Gratings

    ERIC Educational Resources Information Center

    Van Hook, Stephen J.

    2007-01-01

    The pages of "The Physics Teacher" have featured several clever designs for homemade diffraction gratings using a variety of materials--cloth, lithographic film, wire, compact discs, parts of aerosol spray cans, and pseudoliquids and pseudosolids. A different and inexpensive method I use to make low-resolution diffraction gratings takes advantage…

  7. Generalized upper bound for inelastic diffraction

    NASA Astrophysics Data System (ADS)

    Troshin, S. M.; Tyurin, N. E.

    2017-01-01

    For inelastic diffraction, we obtain an upper bound valid for the whole range of the elastic scattering amplitude variation allowed by unitarity. We discuss the energy dependence of the inelastic diffractive cross-section on the base of this bound and recent Large Hadron Collider (LHC) data.

  8. Diffraction from a liquid crystal phase grating.

    PubMed

    Kashnow, R A; Bigelow, J E

    1973-10-01

    The diffraction of light by a sinusoidal perturbation of the optic axis in a nematic liquid crystal is discussed. This corresponds to experiments at the electrohydrodynamic instability thresholds. An interesting qualitative feature appears: The diffraction pattern exhibits a contribution at half of the expected spatial frequency, corresponding to nonorthogonal traversals of the thick phase grating.

  9. Diffraction experiments with infrared remote controls

    NASA Astrophysics Data System (ADS)

    Kuhn, Jochen; Vogt, Patrik

    2012-02-01

    In this paper we describe an experiment in which radiation emitted by an infrared remote control is passed through a diffraction grating. An image of the diffraction pattern is captured using a cell phone camera and then used to determine the wavelength of the radiation.

  10. Intensity Measurements in a Fresnel Diffraction Pattern

    ERIC Educational Resources Information Center

    Boyer, R.; Fortin, E.

    1972-01-01

    Describes an undergraduate optics laboratory experiment to verify the law of intensity in the Fesnel diffraction of a thin wire. A gas laser as light source and a photocell as detector scan the diffraction pattern. The agreement with the theoretical pattern is remarkably good. (Author/TS)

  11. Intensity Measurements in a Fresnel Diffraction Pattern

    ERIC Educational Resources Information Center

    Boyer, R.; Fortin, E.

    1972-01-01

    Describes an undergraduate optics laboratory experiment to verify the law of intensity in the Fesnel diffraction of a thin wire. A gas laser as light source and a photocell as detector scan the diffraction pattern. The agreement with the theoretical pattern is remarkably good. (Author/TS)

  12. Diffractive corrections to the cosmological redshift formula

    SciTech Connect

    Hochberg, D.; Kephart, T.W. )

    1991-05-20

    We calculate the exact frequency redshift for fields coupled to gravity in Robertson-Walker backgrounds. The exact redshift factorizes and is proportional to the naive Doppler shift times a term representing diffractive effects. These diffractive corrections can be large for field modes with wavelengths on the order of the horizon size. Implications for cosmological density perturbations are discussed.

  13. White-Light Diffraction with a CD

    ERIC Educational Resources Information Center

    Ivanov, Dragia Trifonov; Nikolaev, Stefan

    2010-01-01

    Various wave optics experiments can be carried out using an ordinary compact disc. The CD is suitable for use as a diffraction grating. For instance, a standard CD (700 MB) has 625 lines/mm. In this article, the authors describe two white-light diffraction demonstrations for a large audience, realizable using a CD (as reflection or transmission…

  14. X-Ray Diffraction Analysis Program

    NASA Technical Reports Server (NTRS)

    Wiedemann, K. E.; Unnam, J.; Naidu, S. V. N.; Houska, C. R.

    1986-01-01

    SOPAD separates overlapping peaks and analyzes derivatives of X-ray diffraction data. SOPAD helps analyst get most information out of available diffraction data. SOPAD uses Marquardt-type nonlinear regression routine to refine initial estimates of individual peak positions, intensities, shapes, and half-widths.

  15. Liquid-Crystal Point-Diffraction Interferometer

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.

    1996-01-01

    Liquid-crystal point-diffraction interferometer (LCPDI) invented to combine flexible control of liquid-crystal phase-shifts with robustness of point-diffraction interferometers. Produces interferograms indicative of shapes of wavefronts of laser beams having passed through or reflected from objects of interest. Interferograms combined in computers to produce phase maps describing wavefronts.

  16. Multilayer diffraction at 104 keV

    NASA Technical Reports Server (NTRS)

    Krieger, Allen S.; Blake, Richard L.; Siddons, D. P.

    1993-01-01

    We have measured the diffraction peak of a W:Si synthetic multilayer reflector at 104 keV using the High Energy Bonse-Hart Camera at the X-17B hard X-ray wiggler beam line of the National Synchrotron Light Source at Brookhaven National Laboratory. The characteristics of the diffraction peak are described and compared to theory.

  17. White-Light Diffraction with a CD

    ERIC Educational Resources Information Center

    Ivanov, Dragia Trifonov; Nikolaev, Stefan

    2010-01-01

    Various wave optics experiments can be carried out using an ordinary compact disc. The CD is suitable for use as a diffraction grating. For instance, a standard CD (700 MB) has 625 lines/mm. In this article, the authors describe two white-light diffraction demonstrations for a large audience, realizable using a CD (as reflection or transmission…

  18. CMS results on exclusive and diffractive production

    SciTech Connect

    Alves, Gilvan A.

    2015-04-10

    We present recent CMS measurements of diffractive and exclusive processes, using data collected at 7 TeV at the LHC. Measurements of soft single- and double-diffractive cross sections are presented, as well as measurements of photon-induced processes including studies of exclusive WW production via photon-photon exchange.

  19. Structure refinement from precession electron diffraction data.

    PubMed

    Palatinus, Lukáš; Jacob, Damien; Cuvillier, Priscille; Klementová, Mariana; Sinkler, Wharton; Marks, Laurence D

    2013-03-01

    Electron diffraction is a unique tool for analysing the crystal structures of very small crystals. In particular, precession electron diffraction has been shown to be a useful method for ab initio structure solution. In this work it is demonstrated that precession electron diffraction data can also be successfully used for structure refinement, if the dynamical theory of diffraction is used for the calculation of diffracted intensities. The method is demonstrated on data from three materials - silicon, orthopyroxene (Mg,Fe)(2)Si(2)O(6) and gallium-indium tin oxide (Ga,In)(4)Sn(2)O(10). In particular, it is shown that atomic occupancies of mixed crystallographic sites can be refined to an accuracy approaching X-ray or neutron diffraction methods. In comparison with conventional electron diffraction data, the refinement against precession diffraction data yields significantly lower figures of merit, higher accuracy of refined parameters, much broader radii of convergence, especially for the thickness and orientation of the sample, and significantly reduced correlations between the structure parameters. The full dynamical refinement is compared with refinement using kinematical and two-beam approximations, and is shown to be superior to the latter two.

  20. Diffraction from HERA to the LHC

    SciTech Connect

    Newman, Paul

    2011-07-15

    Following a 15 year programme of intensive research into diffractive electron-proton scattering at HERA, it is important to transfer the knowledge and experience gained into the LHC programme. This contribution raises some current issues in diffraction at the LHC and suggests ways in which they might be addressed using HERA results.

  1. QCD subgroup on diffractive and forward physics

    SciTech Connect

    Albrow, M.G.; Baker, W.; Bhatti, A.

    1996-10-01

    The goal is to understand the pomeron, and hence the behavior of total cross sections, elastic scattering and diffractive excitation, in terms of the underlying theory, QCD. A description of the basic ideas and phenomenology is followed by a discussion of hadron-hadron and electron-proton experiments. An appendix lists recommended diffractive-physics terms and definitions. 44 refs., 6 figs.

  2. Inquiry with Laser Printer Diffraction Gratings

    ERIC Educational Resources Information Center

    Van Hook, Stephen J.

    2007-01-01

    The pages of "The Physics Teacher" have featured several clever designs for homemade diffraction gratings using a variety of materials--cloth, lithographic film, wire, compact discs, parts of aerosol spray cans, and pseudoliquids and pseudosolids. A different and inexpensive method I use to make low-resolution diffraction gratings takes advantage…

  3. Dolly For Heavy Towbar

    NASA Technical Reports Server (NTRS)

    Soper, Terry A.

    1992-01-01

    Proposed lightweight dolly enables operator to cart heavy towbar to remote site over unpaved roads or rough terrain. Acts as simple, lightweight towed vehicle to support rear of towbar. Removed quickly at point of use. Saves labor, and eliminates need for truck and forklift.

  4. Resonances in heavy systems

    SciTech Connect

    Betts, R.R.

    1983-01-01

    The experimental situation for the study of resonances in heavy-ion collisions is reviewed, with emphasis on the heaviest systems. New data are presented which show some of the systematics of this phenomenon. The narrow resonance structures are established as a feature of the nuclear structure of the composite system rather than a purely entrance channel effect.

  5. Heavy Vehicle Systems

    SciTech Connect

    Sid Diamond; Richard Wares; Jules Routbort

    2000-04-11

    Heavy Vehicle (HV) systems are a necessary component of achieving OHVT goals. Elements are in place for a far-ranging program: short, intermediate, and long-term. Solicitation will bring industrial input and support. Future funding trend is positive, outlook for HV systems is good.

  6. STAR heavy flavor tracker

    NASA Astrophysics Data System (ADS)

    Qiu, Hao

    2014-11-01

    Hadrons containing heavy quarks are a clean probe of the early dynamic evolution of the dense and hot medium created in high-energy nuclear collisions. To explore heavy quark production at RHIC, the Heavy Flavor Tracker (HFT) for the STAR experiment was built and installed in time for RHIC Run 14. The HFT consists of four layers of silicon detectors. The two outermost layers are silicon strip detectors and the two innermost layers are made from state-of-the-art ultra-thin CMOS Monolithic Active Pixel Sensors (MAPS). This is the first application of a CMOS MAPS detector in a collider experiment. The use of thin pixel sensors plus the use of carbon fiber supporting material limits the material budget to be only 0.4% radiation length per pixel detector layer, enabling the reconstruction of low pT heavy flavor hadrons. The status and performance of the HFT in the RHIC 200 GeV Au + Au run in 2014 are reported. Very good detector efficiency, hit residuals and track resolution (DCAs) were observed in the cosmic ray data and in the Au + Au data.

  7. Heavy Quark Fluorescence

    SciTech Connect

    Torres-Rincon, Juan M.; Llanes-Estrada, Felipe J.

    2010-07-09

    Heavy hadrons containing heavy quarks (for example, {Upsilon} mesons) feature a scale separation between the heavy-quark mass and the QCD scale that controls the effective masses of lighter constituents. As in ordinary molecules, the deexcitation of the lighter, faster degrees of freedom leaves the velocity distribution of the heavy quarks unchanged, populating the available decay channels in qualitatively predictable ways. Automatically an application of the Franck-Condon principle of molecular physics explains several puzzling results of {Upsilon}(5S) decays as measured by the Belle Collaboration, such as the high rate of B{sub s}*B{sub s}* versus B{sub s}*B{sub s} production, the strength of three-body B{sup *}B{pi} decays, or the dip in B momentum shown in these decays. We argue that the data show the first Sturm-Liouville zero of the {Upsilon}(5S) quantum-mechanical squared wave function and provide evidence for a largely bb composition of this meson.

  8. Heavy menstrual bleeding.

    PubMed

    Pearce, Lynne

    2016-10-05

    Essential facts Heavy menstrual bleeding (HMB) is defined as excessive menstrual blood loss that interferes with a woman's physical, emotional, social or material quality of life. In England and Wales, around 80,000 women a year will be referred for the first time to secondary care, with 30,000 requiring surgical treatment.

  9. Heavy-ion radiography and heavy-ion computed tomography

    SciTech Connect

    Fabrikant, J.I.; Holley, W.R.; McFarland, E.W.; Tobias, C.a.

    1982-02-01

    Heavy-ion projection and CT radiography is being developed into a safe, low-dose, noninvasive radiological procedure that can quantitate and image small density differences in human tissues. The applications to heavy-ion mammography and heavy-ion CT imaging of the brain in clinical patients suggest their potential value in cancer diagnosis.

  10. Fraunhofer diffraction by arbitrary-shaped obstacles.

    PubMed

    Malinka, Aleksey V; Zege, Eleonora P

    2009-08-01

    We consider Fraunhofer diffraction by an ensemble of large arbitrary-shaped screens that are randomly oriented in the plane of a wavefront and have edges of arbitrary shape. It is shown that far outside the main diffraction peak the differential scattering cross section behaves asymptotically as theta(-3), where theta is the diffraction angle. Moreover, the differential scattering cross section depends only on the length of the contours bordering the screens and does not depend on the shape of the obstacles. As both strictly forward and total diffraction cross sections are specified by obstacle area only, the differential cross section of size-distributed obstacles is expected to be nearly independent of obstacle shape over the entire region of the diffraction angles.

  11. Coherence and sampling requirements for diffractive imaging.

    PubMed

    Spence, J C H; Weierstall, U; Howells, M

    2004-11-01

    Coherent Diffractive Imaging (CDI) allows images to be reconstructed from diffraction patterns by solving the non-crystallographic phase problem for isolated nanostructures. We show that the Shannon sampling of diffraction intensities needed in CDI requires a coherence width about twice the lateral dimensions of the object, and that the linear number of detector pixels fixes the energy spread needed in the beam. The Shannon sampling, defined by the transform of the periodically repeated autocorrelation of the object, is related to Bragg scattering from an equivalent crystal, and shown to be consistent with the sampling of Young's fringes established by scattering from extreme points in the object. The results are relevant to the design of diffraction cameras for CDI and plans for femotosecond X-ray diffraction from individual proteins.

  12. Nonlinear diffraction in orientation-patterned semiconductors.

    PubMed

    Karpinski, Pawel; Chen, Xin; Shvedov, Vladlen; Hnatovsky, Cyril; Grisard, Arnaud; Lallier, Eric; Luther-Davies, Barry; Krolikowski, Wieslaw; Sheng, Yan

    2015-06-01

    This work represents experimental demonstration of nonlinear diffraction in an orientation-patterned semiconducting material. By employing a new transverse geometry of interaction, three types of second-order nonlinear diffraction have been identified according to different configurations of quasi-phase matching conditions. Specifically, nonlinear Čerenkov diffraction is defined by the longitudinal quasi-phase matching condition, nonlinear Raman-Nath diffraction satisfies only the transverse quasi-phase matching condition, and nonlinear Bragg diffraction fulfils the full vectorial quasi-phase matching conditions. The study extends the concept of transverse nonlinear parametric interaction toward infrared frequency conversion in semiconductors. It also offers an effective nondestructive method to visualise and diagnose variations of second-order nonlinear coefficients inside semiconductors.

  13. Color characterization of coatings with diffraction pigments.

    PubMed

    Ferrero, A; Bernad, B; Campos, J; Perales, E; Velázquez, J L; Martínez-Verdú, F M

    2016-10-01

    Coatings with diffraction pigments present high iridescence, which needs to be characterized in order to describe their appearance. The spectral bidirectional reflectance distribution functions (BRDFs) of six coatings with SpectraFlair diffraction pigments were measured using the robot-arm-based goniospectrophotometer GEFE, designed and developed at CSIC. Principal component analysis has been applied to study the coatings of BRDF data. From data evaluation and based on theoretical considerations, we propose a relevant geometric factor to study the spectral reflectance and color gamut variation of coatings with diffraction pigments. At fixed values of this geometric factor, the spectral BRDF component due to diffraction is almost constant. Commercially available portable goniospectrophotometers, extensively used in several industries (automotive and others), should be provided with more aspecular measurement angles to characterize the complex reflectance of goniochromatic coatings based on diffraction pigments, but they would not require either more than one irradiation angle or additional out-of-plane geometries.

  14. Heavy Flavor Dynamics in Relativistic Heavy-ion Collisions

    NASA Astrophysics Data System (ADS)

    Cao, Shanshan

    Heavy flavor hadrons serve as valuable probes of the transport properties of the quark-gluon plasma (QGP) created in relativistic heavy-ion collisions. In this dissertation, we introduce a comprehensive framework that describes the full-time evolution of heavy flavor in heavy-ion collisions, including its initial production, in-medium evolution inside the QGP matter, hadronization process from heavy quarks to their respective mesonic bound states and the subsequent interactions between heavy mesons and the hadron gas. The in-medium energy loss of heavy quarks is studied within the framework of a Langevin equation coupled to hydrodynamic models that simulate the space-time evolution of the hot and dense QGP matter. We improve the classical Langevin approach such that, apart from quasi-elastic scatterings between heavy quarks and the medium background, radiative energy loss is incorporated as well by treating gluon radiation as a recoil force term. The subsequent hadronization of emitted heavy quarks is simulated via a hybrid fragmentation plus recombination model. The propagation of produced heavy mesons in the hadronic phase is described using the ultra-relativistic quantum molecular dynamics (UrQMD) model. Our calculation shows that while collisional energy loss dominates the heavy quark motion inside the QGP in the low transverse momentum (p T) regime, contributions from gluon radiation are found to be significant at high pT. The recombination mechanism is important for the heavy flavor meson production at intermediate energies. The hadronic final state interactions further enhance the suppression and the collective flow of heavy mesons we observe. Within our newly developed framework, we present numerical results for the nuclear modification and the elliptic flow of D mesons, which are consistent with measurements at both the CERN Large Hadron Collider (LHC) and the BNL Relativistic Heavy-Ion Collider (RHIC); predictions for B mesons are also provided. In

  15. Heavy quarks and lattice QCD

    SciTech Connect

    Andreas S. Kronfeld

    2003-11-05

    This paper is a review of heavy quarks in lattice gauge theory, focusing on methodology. It includes a status report on some of the calculations that are relevant to heavy-quark spectroscopy and to flavor physics.

  16. [Galactic heavy charged particles damaging effect on biological structures].

    PubMed

    Grigor'ev, A I; Krasavin, E A; Ostrovskiĭ, M A

    2013-03-01

    A concept of the radiation risk of the manned interplanetary flights is proposed and substantiated. Heavy charged particles that are a component of the galactic cosmic rays (GCR) have a high damaging effect on the biological structures as great amount of energy is deposited in heavy particle tracks. The high biological effectiveness of heavy ions is observed in their action on cell genetic structures and the whole organism, including the brain structures. The hippocampus is the part of the central nervous system that is the most sensitive to radiation--first of all, to heavy charged particles. Irradiation of animals with accelerated iron ions at doses corresponding to the real fluxes of GCR heavy nuclei, to which Mars mission crews can be exposed, leads to marked behavioral function disorders in the post-irradiation period. To evaluate the radiation risk for the interplanetary flight crews, the concept of successful mission accomplishment is introduced. In these conditions, the central nervous system structures can be the critical target of GCR heavy nuclei. Their damage can modify the higher integrative functions of the brain and cause disorders in the crew members' operator performances.

  17. Estimates of signals in LCLS diffraction imaging experiments

    SciTech Connect

    Chapman, H N

    2004-12-17

    In the coherent X-ray diffraction imaging experiments, samples will be injected or placed in the beam and a two-dimensional diffraction pattern will be collected for a single pulse. This is repeated for a large number of pulses, with the data being read out of the detector each pulse, and stored if the data meets a requirement of enough total recorded counts. There must be sufficient pixels in the detector to over-sample the diffraction pattern, which depends on the sample size and desired resolution, as described below. The scattering from the sample covers a large dynamic range: it is strong very close to the central core and at high angles there will be much less than one photon per pixel. Since the technique relies upon classifying and averaging a large number of patterns, the read noise must be considerably less than the photon count per pixel averaged over these patterns. Estimates of the noise level and dynamic range are given below, after first listing the requirements of pixel count and sampling.

  18. Leaching Properties of Naturally Occurring Heavy Metals from Soils

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Hoshino, M.; Yoshikawa, M.; Hara, J.; Sugita, H.

    2014-12-01

    The major threats to human health from heavy metals are associated with exposure to arsenic, lead, cadmium, chromium, mercury, as well as some other elements. The effects of such heavy metals on human health have been extensively studied and reviewed by international organizations such as WHO. Due to their toxicity, heavy metal contaminations have been regulated by national environmental standards in many countries, and/or laws such as the Soil Contamination Countermeasures Act in Japan. Leaching of naturally occurring heavy metals from the soils, especially those around abandoned metal mines into surrounding water systems, either groundwater or surface water systems, is one of the major pathways of exposure. Therefore, understanding the leaching properties of toxic heavy metals from naturally polluted soils is of fundamentally importance for effectively managing abandoned metal mines, excavated rocks discharged from infrastructure constructions such as tunneling, and/or selecting a pertinent countermeasure against pollution when it is necessary. In this study, soil samples taken from the surroundings of abandoned metal mines in different regions in Japan were collected and analyzed. The samples contained multiple heavy metals such as lead, arsenic and chromium. Standard leaching test and sequential leaching test considering different forms of contaminants, such as trivalent and pentavalent arsenics, and trivalent and hexavalent chromiums, together with standard test for evaluating total concentration, X-ray Fluorescence Analysis (XRF), X-ray diffraction analysis (XRD) and Cation Exchange Capacity (CEC) tests were performed. In addition, sequential leaching tests were performed to evaluate long-term leaching properties of lead from representative samples. This presentation introduces the details of the above experimental study, discusses the relationships among leaching properties and chemical and mineral compositions, indicates the difficulties associated with

  19. Central line infections - hospitals

    MedlinePlus

    ... infection; CVC - infection; Central venous device - infection; Infection control - central line infection; Nosocomial infection - central line infection; Hospital acquired infection - central line infection; Patient safety - central ...

  20. Chromatic confocal microscopy using staircase diffractive surface.

    PubMed

    Rayer, Mathieu; Mansfield, Daniel

    2014-08-10

    A chromatic confocal microscope (CCM) is a high-dynamic-range noncontact distance measurement sensor; it is based on a hyperchromatic lens. The vast majority of commercial CCMs use refractive-based chromatic dispersion to chromatically code the optical axis. This approach significantly limits the range of applications and performance of the CCM. In order to be a suitable alternative to a laser triangulation gauge and laser encoder, the performance of the CCM must be improved. In this paper, it is shown how hybrid aspheric diffractive (HAD) lenses can bring the CCM to its full potential by increasing the dynamic range by a factor of 2 and the resolution by a factor of 5 while passively athermizing and increasing the light throughput efficiency of the optical head [M. Rayer, U.S. patent 1122052.2 (2011)]. The only commercially suitable manufacturing process is single-point diamond turning. However, the optical power carried by the diffractive side of a hybrid aspheric diffractive lens is limited by the manufacturing process. A theoretical study of manufacturing losses has revealed that the HAD configuration with the highest diffraction efficiency is for a staircase diffractive surface (SDS). SDS lenses have the potential to reduce light losses associated with manufacturing limits by a factor of 5 without increasing surface roughness, allowing scalar diffraction-limited optical design with a diffractive element.

  1. Instanton effects on the heavy-quark static potential

    NASA Astrophysics Data System (ADS)

    Yakhshiev, U. T.; Kim, Hyun-Chul; Turimov, B.; Musakhanov, M. M.; Hiyama, Emiko

    2017-08-01

    We investigate instanton effects on the heavy-quark potential, including its spin-dependent part, based on the instanton liquid model. Starting with the central potential derived from the instanton vacuum, we obtain the spin-dependent part of the heavy-quark potential. We discuss the results of the heavy-quark potential from the instanton vacuum. Finally, we solve the nonrelativistic two-body problem, associated with the heavy-quark potential from the instanton vacuum. The instanton effects on the quarkonia spectra are marginal but are required for quantitative description of the spectra. Supported by Basic Science Research Program through the National Research Foundation (NRF) of Korea funded by the Korean government (Ministry of Education, Science and Technology, MEST), Grant Numbers 2016R1D1A1B03935053 (UY) and 2015R1D1A1A01060707 (HChK) and The work was also partly Supported by RIKEN iTHES Project

  2. Detection of heavy metal by paper-based microfluidics.

    PubMed

    Lin, Yang; Gritsenko, Dmitry; Feng, Shaolong; Teh, Yi Chen; Lu, Xiaonan; Xu, Jie

    2016-09-15

    Heavy metal pollution has shown great threat to the environment and public health worldwide. Current methods for the detection of heavy metals require expensive instrumentation and laborious operation, which can only be accomplished in centralized laboratories. Various microfluidic paper-based analytical devices have been developed recently as simple, cheap and disposable alternatives to conventional ones for on-site detection of heavy metals. In this review, we first summarize current development of paper-based analytical devices and discuss the selection of paper substrates, methods of device fabrication, and relevant theories in these devices. We then compare and categorize recent reports on detection of heavy metals using paper-based microfluidic devices on the basis of various detection mechanisms, such as colorimetric, fluorescent, and electrochemical methods. To finalize, the future development and trend in this field are discussed.

  3. Future of Electron Scattering and Diffraction

    SciTech Connect

    Hall, Ernest; Stemmer, Susanne; Zheng, Haimei; Zhu, Yimei; Maracas, George

    2014-02-25

    spectroscopy with high spatial resolution without damaging their structure. The strong interaction of electrons with matter allows high-energy electron pulses to gather structural information before a sample is damaged. Electron ScatteringImaging, diffraction, and spectroscopy are the fundamental capabilities of electron-scattering instruments. The DOE BES-funded TEAM (Transmission Electron Aberration-corrected Microscope) project achieved unprecedented sub-atomic spatial resolution in imaging through aberration-corrected transmission electron microscopy. To further advance electron scattering techniques that directly enable groundbreaking science, instrumentation must advance beyond traditional two-dimensional imaging. Advances in temporal resolution, recording the full phase and energy spaces, and improved spatial resolution constitute a new frontier in electron microscopy, and will directly address the BES Grand Challenges, such as to “control the emergent properties that arise from the complex correlations of atomic and electronic constituents” and the “hidden states” “very far away from equilibrium”. Ultrafast methods, such as the pump-probe approach, enable pathways toward understanding, and ultimately controlling, the chemical dynamics of molecular systems and the evolution of complexity in mesoscale and nanoscale systems. Central to understanding how to synthesize and exploit functional materials is having the ability to apply external stimuli (such as heat, light, a reactive flux, and an electrical bias) and to observe the resulting dynamic process in situ and in operando, and under the appropriate environment (e.g., not limited to UHV conditions). To enable revolutionary advances in electron scattering and science, the participants of the workshop recommended three major new instrumental developments: A. Atomic-Resolution Multi-Dimensional Transmission Electron Microscope: This instrument would provide quantitative information over the entire real space

  4. Ultra-relativistic heavy ions and cosmic rays

    NASA Astrophysics Data System (ADS)

    McLerran, L.

    1983-05-01

    The collisions of ultra-relativistic heavy ions, E/sub /N/ greater than or equal to 1 TeV/nucleon are most interesting, since, at these energies, matter is produced at a sufficiently high energy density that a quark-gluon plasma has a good chance to form. Very heavy ions are also most interesting since the matter forms in a larger volume than for light ions, and the matter is at a somewhat higher density. At very high energies with very heavy ions there is great flexibility in the experimental signals which might be studied, as well as the nature of the matter which is produced. The fragmentation region and central region provide different environments where a plasma might form. The former is baryon rich while the central region is high temperature with low baryon number density and is not accessible except at very high energies.

  5. Ultra-relativistic heavy ions and cosmic rays

    SciTech Connect

    McLerran, L.

    1983-05-01

    The collisions of ultra-relativistic heavy ions, E/sub /N/ greater than or equal to 1 TeV/nucleon are most interesting, since, at these energies, matter is produced at sufficiently high energy density that a quark-gluon plasma has a good chance to form. Very heavy ions are also most interesting since the matter forms in a larger volume than for light ions, and the matter is at a somewhat higher energy density. At very high energies with very heavy ions there is great flexibility in the experimental signals which might be studied, as well as the nature of the matter which is produced. The fragmentation region and central region provide different environments where a plasma might form. The former is baryon rich while the central region is high temperature with low baryon number density and is not accessible except at very high energies.

  6. Examining Factors Associated with Heavy Episodic Drinking Among College Undergraduates

    PubMed Central

    Scholly, Kristen; Katz, Alan R.; Kehl, Lisa

    2014-01-01

    Heavy episodic drinking among college students is a serious health concern. The purpose of this study was to identify factors associated with heavy episodic drinking behaviors amongst a predominately Asian undergraduate college student population in the United States. A survey measuring alcohol use behaviors was completed by a random sample of 18-24 year old undergraduates during April, 2011. A multivariate logistic regression analysis was conducted to determine factors associated with students’ heavy episodic drinking behavior. Independent factors associated with heavy episodic drinking included living on campus, ethnicity, perceived drinking behavior among peers, and a belief that alcohol is a central part of one’s social life. Heavy episodic drinking was also associated with poor academic performance. Campus-wide educational strategies to reduce heavy episodic drinking among college undergraduates should incorporate accurate information regarding alcohol use norms to correct students’ perceived over estimation of their peers alcohol consumption rates and the under estimation of students protective alcohol use behaviors. These efforts should focus in on-campus residence halls where a higher occurrence of heavy episodic drinking is often found. PMID:26973931

  7. Examining Factors Associated with Heavy Episodic Drinking Among College Undergraduates.

    PubMed

    Scholly, Kristen; Katz, Alan R; Kehl, Lisa

    2014-04-26

    Heavy episodic drinking among college students is a serious health concern. The purpose of this study was to identify factors associated with heavy episodic drinking behaviors amongst a predominately Asian undergraduate college student population in the United States. A survey measuring alcohol use behaviors was completed by a random sample of 18-24 year old undergraduates during April, 2011. A multivariate logistic regression analysis was conducted to determine factors associated with students' heavy episodic drinking behavior. Independent factors associated with heavy episodic drinking included living on campus, ethnicity, perceived drinking behavior among peers, and a belief that alcohol is a central part of one's social life. Heavy episodic drinking was also associated with poor academic performance. Campus-wide educational strategies to reduce heavy episodic drinking among college undergraduates should incorporate accurate information regarding alcohol use norms to correct students' perceived over estimation of their peers alcohol consumption rates and the under estimation of students protective alcohol use behaviors. These efforts should focus in on-campus residence halls where a higher occurrence of heavy episodic drinking is often found.

  8. Limb Heaviness: A Perceptual Phenomenon Associated With Poststroke Fatigue?

    PubMed

    Kuppuswamy, Annapoorna; Clark, Ella; Rothwell, John; Ward, Nick S

    2016-05-01

    Poststroke fatigue and limb heaviness are 2 perceptual problems that commonly occur after stroke. Previous work suggests that poststroke fatigue may be related to altered sensorimotor processing whereas limb heaviness is often considered an association of muscle weakness. To address the hypothesis that the perception of limb heaviness may also be a problem of altered sensorimotor control, we investigated whether it was more closely related to poststroke fatigue or muscle weakness. In 69 chronic stroke survivors, we found that those with high perceived limb heaviness (31 individuals) also reported significantly higher levels of fatigue (4.8/7) than those with no perceived limb heaviness (38 individuals, fatigue score = 2.68/7), but there was no difference in weakness between the 2 groups. This intriguing finding is discussed in relation to effort perception and sensory processing. The association between limb heaviness and poststroke fatigue and a dissociation from muscle weakness gives rise to the hypothesis that limb heaviness maybe a centrally arising sensorimotor disorder.

  9. HIGH-PRECISION ASTROMETRY WITH A DIFFRACTIVE PUPIL TELESCOPE

    SciTech Connect

    Guyon, Olivier; Eisner, Josh A.; Angel, Roger; Woolf, Neville J.; Bendek, Eduardo A.; Milster, Thomas D.; Mark Ammons, S.; Shao, Michael; Shaklan, Stuart; Levine, Marie; Nemati, Bijan; Pitman, Joe; Woodruff, Robert A.; Belikov, Ruslan

    2012-06-01

    Astrometric detection and mass determination of Earth-mass exoplanets require sub-{mu}as accuracy, which is theoretically possible with an imaging space telescope using field stars as an astrometric reference. The measurement must, however, overcome astrometric distortions, which are much larger than the photon noise limit. To address this issue, we propose to generate faint stellar diffraction spikes using a two-dimensional grid of regularly spaced small dark spots added to the surface of the primary mirror (PM). Accurate astrometric motion of the host star is obtained by comparing the position of the spikes to the background field stars. The spikes do not contribute to scattered light in the central part of the field and therefore allow unperturbed coronagraphic observation of the star's immediate surroundings. Because the diffraction spikes are created on the PM and imaged on the same focal plane detector as the background stars, astrometric distortions affect equally the diffraction spikes and the background stars and are therefore calibrated. We describe the technique, detail how the data collected by the wide-field camera are used to derive astrometric motion, and identify the main sources of astrometric error using numerical simulations and analytical derivations. We find that the 1.4 m diameter telescope, 0.3 deg{sup 2} field we adopt as a baseline design achieves 0.2 {mu}as single measurement astrometric accuracy. The diffractive pupil concept thus enables sub-{mu}as astrometry without relying on the accurate pointing, external metrology, or high-stability hardware required with previously proposed high-precision astrometry concepts.

  10. Heavy Quarkonia on the Light Front

    NASA Astrophysics Data System (ADS)

    Li, Yang; Chen, Guangyao; Adhikari, Lekha; Zhao, Xingbo; Maris, Pieter; Vary, James

    2016-03-01

    We employ solutions for heavy quarkonium within a light-front basis function approach to compare with experiment and predict additional observables. The Hamiltonian is based on the Light-Front Holographic QCD (phenomenological confinement) plus one-gluon exchange. Mass spectra agree well with experiment and we employ the wavefunctions to evaluate decay constants and form factors. We discuss our progress and plans for evaluating generalized parton distributions (GPDs) and cross sections for diffractive production. Our predictions for these observables as well as predictions of additional excited states can be tested at ongoing and future experimental facilities, e.g., LHC, sPHENIX and the EIC. We acknowledge DOE Grants DE-FG02-87ER40371 & DESC0008485.

  11. 3D printed diffractive terahertz lenses.

    PubMed

    Furlan, Walter D; Ferrando, Vicente; Monsoriu, Juan A; Zagrajek, Przemysław; Czerwińska, Elżbieta; Szustakowski, Mieczysław

    2016-04-15

    A 3D printer was used to realize custom-made diffractive THz lenses. After testing several materials, phase binary lenses with periodic and aperiodic radial profiles were designed and constructed in polyamide material to work at 0.625 THz. The nonconventional focusing properties of such lenses were assessed by computing and measuring their axial point spread function (PSF). Our results demonstrate that inexpensive 3D printed THz diffractive lenses can be reliably used in focusing and imaging THz systems. Diffractive THz lenses with unprecedented features, such as extended depth of focus or bifocalization, have been demonstrated.

  12. New diffractive results from the Tevatron

    SciTech Connect

    Gallinaro, Michele; /Rockefeller U.

    2005-05-01

    Experimental results in diffractive processes are summarized and a few notable characteristics described in terms of Quantum Chromodynamics. Exclusive dijet production is used to establish a benchmark for future experiments in the quest for diffractive Higgs production at the Large Hadron Collider. Using new data from the Tevatron and dedicated diffractive triggers, no excess over a smooth falling distribution for exclusive dijet events could be found. Stringent upper limits on the exclusive dijet production cross section are presented. The quark/gluon composition of dijet final states is used to provide additional hints on exclusive dijet production.

  13. Novel Aspects of Hard Diffraction in QCD

    SciTech Connect

    Brodsky, Stanley J.; /SLAC

    2005-12-14

    Initial- and final-state interactions from gluon-exchange, normally neglected in the parton model have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, and nuclear shadowing and antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency.

  14. Nuclear Resonant Surface Diffraction of Synchrotron Radiation

    NASA Astrophysics Data System (ADS)

    Schlage, Kai; Dzemiantsova, Liudmila; Bocklage, Lars; Wille, Hans-Christian; Pues, Matthias; Meier, Guido; Röhlsberger, Ralf

    2017-06-01

    Nuclear resonant x-ray diffraction in grazing incidence geometry is used to determine the lateral magnetic configuration in a one-dimensional lattice of ferromagnetic nanostripes. During magnetic reversal, strong nuclear superstructure diffraction peaks appear in addition to the electronic ones due to an antiferromagnetic order in the nanostripe lattice. We show that the analysis of the angular distribution together with the time dependence of the resonantly diffracted x rays reveals surface spin structures with very high sensitivity. This scattering technique provides unique access to laterally correlated spin configurations in magnetically ordered nanostructures and, in perspective, also to their dynamics.

  15. Controlled double-slit electron diffraction

    NASA Astrophysics Data System (ADS)

    Bach, Roger; Pope, Damian; Liou, Sy-Hwang; Batelaan, Herman

    2013-03-01

    Double-slit diffraction is a corner stone of quantum mechanics. It illustrates key features of quantum mechanics: interference and the particle-wave duality of matter. In 1965, Richard Feynman presented a thought experiment to show these features. Here we demonstrate the full realization of his famous thought experiment. By placing a movable mask in front of a double-slit to control the transmission through the individual slits, probability distributions for single- and double-slit arrangements were observed. Also, by recording single electron detection events diffracting through a double-slit, a diffraction pattern was built up from individual events.

  16. Imaging performance tests of diffractive optical system

    NASA Astrophysics Data System (ADS)

    Jiao, Jianchao; Su, Yun; Wang, Baohua; Wang, Chao; Zhang, Yue; Jin, Jiangao

    2016-10-01

    Diffractive optical imaging is a new method to realize high-resolution imaging from geostationary orbit(GEO). Technical advantages of diffractive optical imaging is analyzed in the field of space optics. For application of super large diameter space optical system, the system scheme and a new achromatic method is proposed. An imaging system is developed and tested, the result of optical system wavefront is 0.169λ(RMS), optical system MTF is 0.85, and the imaging system MTF is 0.19. Test results show the new achromatic method is feasible. The above conclusions have reference significance for the development of super large diameter diffractive optical imaging system.

  17. Binary logic based purely on Fresnel diffraction

    NASA Astrophysics Data System (ADS)

    Hamam, H.; de Bougrenet de La Tocnaye, J. L.

    1995-09-01

    Binary logic operations on two-dimensional data arrays are achieved by use of the self-imaging properties of Fresnel diffraction. The fields diffracted by periodic objects can be considered as the superimposition of weighted and shifted replicas of original objects. We show that a particular spatial organization of the input data can result in logical operations being performed on these data in the considered diffraction planes. Among various advantages, this approach is shown to allow the implementation of dual-track, nondissipative logical operators. Image algebra is presented as an experimental illustration of this principle.

  18. A scattering approach to sea wave diffraction

    SciTech Connect

    Corradini, M. L. Garbuglia, M. Maponi, P.; Ruggeri, M.

    2016-06-08

    This paper intends to show a model for the diffraction of sea waves approaching an OWC device, which converts the sea waves motion into mechanical energy and then electrical energy. This is a preliminary study to the optimisation of the device, in fact the computation of sea waves diffraction around the device allows the estimation of the sea waves energy which enters into the device. The computation of the diffraction phenomenon is the result of a sea waves scattering problem, solved with an integral equation method.

  19. Electron Diffraction of Wet Phospholipid Bilayers

    PubMed Central

    Hui, S. W.; Parsons, D. F.; Cowden, M.

    1974-01-01

    The structure of fully hydrated dipalmitoyl lecithin single bilayers, and monolayers deposited on Formvar substrates are studied by electron diffraction, using a hydration stage fitted to an electron microscope. Selective area diffraction patterns of these films indicate that there are domains consisting of mosaics of crystallites of hexagonally packed lipid chains. The size of these domains are typically several μm in diameter. The diffraction intensity agrees with that calculated from the electron scattering factor of the hydrocarbon chains of the lipid molecule. Images PMID:4531037

  20. Nuclear Resonant Surface Diffraction of Synchrotron Radiation.

    PubMed

    Schlage, Kai; Dzemiantsova, Liudmila; Bocklage, Lars; Wille, Hans-Christian; Pues, Matthias; Meier, Guido; Röhlsberger, Ralf

    2017-06-09

    Nuclear resonant x-ray diffraction in grazing incidence geometry is used to determine the lateral magnetic configuration in a one-dimensional lattice of ferromagnetic nanostripes. During magnetic reversal, strong nuclear superstructure diffraction peaks appear in addition to the electronic ones due to an antiferromagnetic order in the nanostripe lattice. We show that the analysis of the angular distribution together with the time dependence of the resonantly diffracted x rays reveals surface spin structures with very high sensitivity. This scattering technique provides unique access to laterally correlated spin configurations in magnetically ordered nanostructures and, in perspective, also to their dynamics.

  1. Diffraction enhanced x-ray imaging

    SciTech Connect

    Thomlinson, W.; Zhong, Z.; Chapman, D.; Johnston, R.E.; Sayers, D.

    1997-09-01

    Diffraction enhanced imaging (DEI) is a new x-ray radiographic imaging modality using synchrotron x-rays which produces images of thick absorbing objects that are almost completely free of scatter. They show dramatically improved contrast over standard imaging applied to the same phantoms. The contrast is based not only on attenuation but also the refraction and diffraction properties of the sample. The diffraction component and the apparent absorption component (absorption plus extinction contrast) can each be determined independently. This imaging method may improve the image quality for medical applications such as mammography.

  2. Strain Determination Using Electron Backscatter Diffraction

    SciTech Connect

    Krause, M.; Graff, A.; Altmann, F.

    2010-11-24

    In the present paper we demonstrate the use of electron backscatter diffraction (EBSD) for high resolution elastic strain determination. Here, we focus on analysis methods based on determination of small shifts in EBSD pattern with respect to a reference pattern using cross-correlation algorithms. Additionally we highlight the excellent spatial and depth resolution of EBSD and introduce the use of simulated diffraction patterns based on dynamical diffraction theory for sensitivity estimation. Moreover the potential of EBSD for strain analysis of strained thin films with particular emphasis on appropriate target preparation which respect to occurring lattice defects is demonstrated.

  3. Diffractive di-jet production at the LHC with a Reggeon contribution

    NASA Astrophysics Data System (ADS)

    Marquet, C.; Martins, D. E.; Pereira, A. V.; Rangel, M.; Royon, C.

    2017-03-01

    We study hard diffractive scattering in hadron-hadron collisions including, on top of the standard Pomeron-initiated processes, contributions due to the exchange of Reggeons. Using a simple model to describe the parton content of the Reggeon, we compute di-jet production in single diffractive and central diffractive events. We show that Reggeon contributions can be sizable at the LHC, and even sometimes dominant, and we identify kinematic windows in which they could be experimentally studied. We argue that suitable measurements must be performed in order to properly constrain the model, and be able to correctly account for Reggeon exchanges in the analysis of the many hard diffractive observables to be measured at the LHC.

  4. A design method based on photonic crystal theory for Bragg concave diffraction grating

    NASA Astrophysics Data System (ADS)

    Du, Bingzheng; Zhu, Jingping; Mao, Yuzheng; Li, Bao; Zhang, Yunyao; Hou, Xun

    2017-02-01

    A design method based on one-dimensional photonic crystal theory (1-D PC theory) is presented to design Bragg concave diffraction grating (Bragg-CDG) for the demultiplexer. With this design method, the reflection condition calculated by the 1-D PC theory can be matched perfectly with the diffraction condition. As a result, the shift of central wavelength of diffraction spectra can be improved, while keeping high diffraction efficiency. Performances of Bragg-CDG for TE and TM-mode are investigated, and the simulation results are consistent with the 1-D PC theory. This design method is expected to be applied to improve the accuracy and efficiency of Bragg-CDG after further research.

  5. Diffraction and Imaging Study of Imperfections of Protein Crystals with Coherent X-rays

    NASA Technical Reports Server (NTRS)

    Hu, Z. W.; Thomas, B. R.; Chernov, A. A.; Chu, Y. S.; Lai, B.

    2004-01-01

    High angular-resolution x-ray diffraction and phase contrast x-ray imaging were combined to study defects and perfection of protein crystals. Imperfections including line defects, inclusions and other microdefects were observed in the diffraction images of a uniformly grown lysozyme crystal. The observed line defects carry distinct dislocation features running approximately along the <110> growth front and have been found to originate mostly in a central growth area and occasionally in outer growth regions. Slow dehydration led to the broadening of a fairly symmetric 4 4 0 rocking curve by a factor of approximately 2.6, which was primarily attributed to the dehydration-induced microscopic effects that are clearly shown in diffraction images. X-ray imaging and diffraction characterization of the quality of apoferritin crystals will also be discussed in the presentation.

  6. Diffraction and Imaging Study of Imperfections of Protein Crystals with Coherent X-rays

    NASA Technical Reports Server (NTRS)

    Hu, Z. W.; Thomas, B. R.; Chernov, A. A.; Chu, Y. S.; Lai, B.

    2004-01-01

    High angular-resolution x-ray diffraction and phase contrast x-ray imaging were combined to study defects and perfection of protein crystals. Imperfections including line defects, inclusions and other microdefects were observed in the diffraction images of a uniformly grown lysozyme crystal. The observed line defects carry distinct dislocation features running approximately along the <110> growth front and have been found to originate mostly in a central growth area and occasionally in outer growth regions. Slow dehydration led to the broadening of a fairly symmetric 4 4 0 rocking curve by a factor of approximately 2.6, which was primarily attributed to the dehydration-induced microscopic effects that are clearly shown in diffraction images. X-ray imaging and diffraction characterization of the quality of apoferritin crystals will also be discussed in the presentation.

  7. Comparing Tsallis and Boltzmann temperatures from relativistic heavy ion collider and large hadron collider heavy-ion data

    NASA Astrophysics Data System (ADS)

    Gao, Y.-Q.; Liu, F.-H.

    2016-03-01

    The transverse momentum spectra of charged particles produced in Au + Au collisions at the relativistic heavy ion collider and in Pb + Pb collisions at the large hadron collider with different centrality intervals are described by the multisource thermal model which is based on different statistic distributions for a singular source. Each source in the present work is described by the Tsallis distribution and the Boltzmann distribution, respectively. Then, the interacting system is described by the (two-component) Tsallis distribution and the (two-component) Boltzmann distribution, respectively. The results calculated by the two distributions are in agreement with the experimental data of the Solenoidal Tracker At Relativistic heavy ion collider, Pioneering High Energy Nuclear Interaction eXperiment, and A Large Ion Collider Experiment Collaborations. The effective temperature parameters extracted from the two distributions on the descriptions of heavy-ion data at the relativistic heavy ion collider and large hadron collider are obtained to show a linear correlation.

  8. Detecting heavy quarks

    SciTech Connect

    Benenson, G.; Chau, L.L.; Ludlam, T.; Paige, F.E.; Platner, E.D.; Protopopescu, S.D.; Rehak, P.

    1983-01-01

    In this exercise we examine the performance of a detector specifically configured to tag heavy quark (HQ) jets through direct observations of D-meson decays with a high resolution vertex detector. To optimize the performance of such a detector, we assume the small diamond beam crossing configuration as described in the 1978 ISABELLE proposal, giving a luminosity of 10/sup 32/ cm/sup -2/ sec/sup -1/. Because of the very large backgrounds from light quark (LQ) jets, most triggering schemes at this luminosity require high P/sub perpendicular to/ leptons and inevitably give missing neutrinos. If alternative triggering schemes could be found, then one can hope to find and calculate the mass of objects decaying to heavy quarks. A scheme using the high resolution detector will also be discussed in detail. The study was carried out with events generated by the ISAJET Monte Carlo and a computer simulation of the described detector system. (WHK)

  9. Heavy Vehicle Propulsion Materials

    SciTech Connect

    Ray Johnson

    2000-01-31

    The objectives are to Provide Key Enabling Materials Technologies to Increase Energy Efficiency and Reduce Exhaust Emissions. The following goals are listed: Goal 1: By 3rd quarter 2002, complete development of materials enabling the maintenance or improvement of fuel efficiency {ge} 45% of class 7-8 truck engines while meeting the EPA/Justice Department ''Consent Decree'' for emissions reduction. Goal 2: By 4th quarter 2004, complete development of enabling materials for light-duty (class 1-2) diesel truck engines with efficiency over 40%, over a wide range of loads and speeds, while meeting EPA Tier 2 emission regulations. Goal 3: By 4th quarter 2006, complete development of materials solutions to enable heavy-duty diesel engine efficiency of 50% while meeting the emission reduction goals identified in the EPA proposed rule for heavy-duty highway engines.''

  10. Utah Heavy Oil Program

    SciTech Connect

    J. Bauman; S. Burian; M. Deo; E. Eddings; R. Gani; R. Goel; C.K. Huang; M. Hogue; R. Keiter; L. Li; J. Ruple; T. Ring; P. Rose; M. Skliar; P.J. Smith; J.P. Spinti; P. Tiwari; J. Wilkey; K. Uchitel

    2009-10-20

    The Utah Heavy Oil Program (UHOP) was established in June 2006 to provide multidisciplinary research support to federal and state constituents for addressing the wide-ranging issues surrounding the creation of an industry for unconventional oil production in the United States. Additionally, UHOP was to serve as an on-going source of unbiased information to the nation surrounding technical, economic, legal and environmental aspects of developing heavy oil, oil sands, and oil shale resources. UHOP fulGilled its role by completing three tasks. First, in response to the Energy Policy Act of 2005 Section 369(p), UHOP published an update report to the 1987 technical and economic assessment of domestic heavy oil resources that was prepared by the Interstate Oil and Gas Compact Commission. The UHOP report, entitled 'A Technical, Economic, and Legal Assessment of North American Heavy Oil, Oil Sands, and Oil Shale Resources' was published in electronic and hard copy form in October 2007. Second, UHOP developed of a comprehensive, publicly accessible online repository of unconventional oil resources in North America based on the DSpace software platform. An interactive map was also developed as a source of geospatial information and as a means to interact with the repository from a geospatial setting. All documents uploaded to the repository are fully searchable by author, title, and keywords. Third, UHOP sponsored Give research projects related to unconventional fuels development. Two projects looked at issues associated with oil shale production, including oil shale pyrolysis kinetics, resource heterogeneity, and reservoir simulation. One project evaluated in situ production from Utah oil sands. Another project focused on water availability and produced water treatments. The last project considered commercial oil shale leasing from a policy, environmental, and economic perspective.

  11. Heavy rain field measurements

    NASA Technical Reports Server (NTRS)

    Melson, ED

    1991-01-01

    A weight-measuring rain gauge was developed to collect rain data and configured to operate at a high sample rate (one sample pre second). Instead of averaging the rain rate in minutes, hours, and sometime days as normally performed, the rain data collected are examined in seconds. The results of six field sites are compiled. Rain rate levels, duration of downpours, and frequency of heavy rainfall events are presented.

  12. Retrofitting heavy oil processes

    SciTech Connect

    Hamilton, G.L.; Fitzgerald, M.; D'Amico, V.

    1986-01-01

    Refiners, faced with the need to process the bottom end of the heavy high sulfur crude oil barrel in today's uncertain economic environment, are reluctant to commit large amounts of money to expensive upgrading processes. In order to conserve scarce capital while improving operating margins, additional valuable products can be produced by retrofits such as conversion of an idle crude unit to visbreaking, delayed coking or deasphalting service, or conversion of hydrodesulfurizers to mild hydrocracking.

  13. Hadroduction of heavy flavors

    SciTech Connect

    Leedom, I.D.

    1986-04-01

    The current state of knowledge of heavy quark production, particularly charm, by hadron beams is reviewed. The state of knowledge of total cross section, p/sub T/ and x/sub F/ dependence of charm hadroproduction is given. Besides D production, production of D* is discussed. Also covered is the present evidence for hadronically produced B mesons. 28 refs., 5 figs., 3 tabs. (LEW)

  14. Search for Heavy Pointlike Dirac Monopoles

    NASA Astrophysics Data System (ADS)

    Abbott, B.; Abolins, M.; Acharya, B. S.; Adam, I.; Adams, D. L.; Adams, M.; Ahn, S.; Aihara, H.; Alves, G. A.; Amos, N.; Anderson, E. W.; Astur, R.; Baarmand, M. M.; Babukhadia, L.; Baden, A.; Balamurali, V.; Balderston, J.; Baldin, B.; Banerjee, S.; Bantly, J.; Barberis, E.; Bartlett, J. F.; Belyaev, A.; Beri, S. B.; Bertram, I.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Biswas, N.; Blazey, G.; Blessing, S.; Bloom, P.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Boswell, C.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoi, V. S.; Butler, J. M.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chang, S.-M.; Chekulaev, S. V.; Chen, L.-P.; Chen, W.; Choi, S.; Chopra, S.; Choudhary, B. C.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Coney, L.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M. A.; Cutts, D.; Dahl, O. I.; Davis, K.; de, K.; del Signore, K.; Demarteau, M.; Denisov, D.; Denisov, S. P.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Draper, P.; Ducros, Y.; Dudko, L. V.; Dugad, S. R.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Evdokimov, V. N.; Fahland, T.; Fatyga, M. K.; Feher, S.; Fein, D.; Ferbel, T.; Finocchiaro, G.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Forden, G. E.; Fortner, M.; Frame, K. C.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gartung, P.; Gavrilov, V.; Geld, T. L.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gershtein, Y.; Gibbard, B.; Glenn, S.; Gobbi, B.; Goldschmidt, A.; Gómez, B.; Gómez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, D. R.; Greenlee, H.; Grinstein, S.; Grudberg, P.; Grünendahl, S.; Guglielmo, G.; Guida, J. A.; Guida, J. M.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, G.; Gutierrez, P.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hahn, K. S.; Hall, R. E.; Hanlet, P.; Hansen, S.; Hauptman, J. M.; Hedin, D.; Heinson, A. P.; Heintz, U.; Hernández-Montoya, R.; Heuring, T.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoftun, J. S.; Hsieh, F.; Hu, Ting; Hu, Tong; Huehn, T.; Ito, A. S.; James, E.; Jaques, J.; Jerger, S. A.; Jesik, R.; Jiang, J. Z.-Y.; Joffe-Minor, T.; Johns, K.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jun, S. Y.; Jung, C. K.; Kahn, S.; Kalbfleisch, G.; Kang, J. S.; Karmanov, D.; Karmgard, D.; Kehoe, R.; Kelly, M. L.; Kim, C. L.; Kim, S. K.; Klima, B.; Klopfenstein, C.; Kohli, J. M.; Koltick, D.; Kostritskiy, A. V.; Kotcher, J.; Kotwal, A. V.; Kourlas, J.; Kozelov, A. V.; Kozlovsky, E. A.; Krane, J.; Krishnaswamy, M. R.; Krzywdzinski, S.; Kuleshov, S.; Kunori, S.; Landry, F.; Landsberg, G.; Lauer, B.; Leflat, A.; Li, H.; Li, J.; Li-Demarteau, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Y. C.; Lobkowicz, F.; Loken, S. C.; Lökös, S.; Lueking, L.; Lyon, A. L.; Maciel, A. K.; Madaras, R. J.; Madden, R.; Magaña-Mendoza, L.; Manankov, V.; Mani, S.; Mao, H. S.; Markeloff, R.; Marshall, T.; Martin, M. I.; Mauritz, K. M.; May, B.; Mayorov, A. A.; McCarthy, R.; McDonald, J.; McKibben, T.; McKinley, J.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miettinen, H.; Mincer, A.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Mooney, P.; da Motta, H.; Murphy, C.; Nang, F.; Narain, M.; Narasimham, V. S.; Narayanan, A.; Neal, H. A.; Negret, J. P.; Nemethy, P.; Norman, D.; Oesch, L.; Oguri, V.; Oliveira, E.; Oltman, E.; Oshima, N.; Owen, D.; Padley, P.; Para, A.; Park, Y. M.; Partridge, R.; Parua, N.; Paterno, M.; Pawlik, B.; Perkins, J.; Peters, M.; Piegaia, R.; Piekarz, H.; Pischalnikov, Y.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Qian, J.; Quintas, P. Z.; Raja, R.; Rajagopalan, S.; Ramirez, O.; Rasmussen, L.; Reucroft, S.; Rijssenbeek, M.; Rockwell, T.; Roco, M.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sánchez-Hernández, A.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Sculli, J.; Shabalina, E.; Shaffer, C.; Shankar, H. C.; Shivpuri, R. K.; Shupe, M.; Singh, H.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, E.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sosebee, M.; Sotnikova, N.; Souza, M.; Spadafora, A. L.; Steinbrück, G.; Stephens, R. W.; Stevenson, M. L.; Stewart, D.; Stichelbaut, F.; Stoker, D.; Stolin, V.; Stoyanova, D. A.; Strauss, M.; Streets, K.; Strovink, M.; Sznajder, A.; Tamburello, P.; Tarazi, J.; Tartaglia, M.; Thomas, T. L.; Thompson, J.; Trippe, T. G.; Tuts, P. M.; Varelas, N.; Varnes, E. W.; Vititoe, D.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, G.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Wightman, J. A.; Willis, S.; Wimpenny, S. J.; Wirjawan, J. V.; Womersley, J.; Won, E.; Wood, D. R.; Xu, H.; Yamada, R.; Yamin, P.; Yang, J.; Yasuda, T.; Yepes, P.; Yoshikawa, C.; Youssef, S.; Yu, J.; Yu, Y.; Zhou, Z.; Zhu, Z. H.; Zieminska, D.; Zieminski, A.; Zverev, E. G.; Zylberstejn, A.

    1998-07-01

    We have searched for central production of a pair of photons with high transverse energies in pp¯ collisions at s = 1.8 TeV using 70 pb-1 of data collected with the D0 detector at the Fermilab Tevatron in 1994-1996. If they exist, virtual heavy pointlike Dirac monopoles could rescatter pairs of nearly real photons into this final state via a box diagram. We observe no excess of events above background, and set lower 95% C.L. limits of 610, 870, or 1580 GeV/c2 on the mass of a spin 0, 1/2, or 1 Dirac monopole.

  15. Geometrical-numerical approach to diffraction phenomena.

    PubMed

    Bosch, S; Ferré-Borrull, J

    2001-02-15

    The calculation of diffracted fields is considered by means of a geometrical analysis of the incoming wave into semiperiodic zones in the aperture plane, followed by a numerical process for addition of the contributions corresponding to the semiperiodic zones. This general approach constitutes a novel interpretation of diffraction phenomena that permits exact evaluation of the mathematical expressions of diffraction theory and overcomes the limitations of any approximation. The method is illustrated by analysis of two important configuration in optics: the pinhole camera, for which we deduce the optimum radius for imaging, and the diffraction of a spherical converging wave through a circular aperture, from which we determine the limit of the validity of the Fraunhofer approximation (i.e., of the Airy pattern) and the influence of the obliquity factor.

  16. Tension in the LHC diffractive data?

    SciTech Connect

    Gotsman, Errol

    2015-04-10

    I discuss the LHC diffractive data, and compare it to predicted energy behaviour of various models. I suggest that the so called 'tension' between the experimental results, maybe due to the different Monte Carlo programs used.

  17. Light diffraction by concentrator Fresnel lenses.

    PubMed

    Hornung, Thorsten; Nitz, Peter

    2014-05-05

    Fresnel lenses are widely used in concentrating photovoltaic (CPV) systems as primary optical elements focusing sunlight onto small solar cells or onto entrance apertures of secondary optical elements attached to the solar cells. Calculations using the Young-Maggi-Rubinowicz theory of diffraction yield analytical expressions for the amount of light spilling outside these target areas due to diffraction at the edges of the concentrator Fresnel lenses. Explicit equations are given for the diffraction loss due to planar Fresnel lenses with small prisms and due to arbitrarily shaped Fresnel lenses. Furthermore, the cases of illumination by monochromatic, polychromatic, totally spatially coherent and partially spatially coherent light (e.g. from the solar disc) are treated, resulting in analytical formulae. Examples using realistic values show losses due to diffraction of up to several percent.

  18. Two-photon x-ray diffraction

    DOE PAGES

    Stohr, J.

    2017-01-11

    The interference pattern of a circular photon source has long been used to define the optical diffraction limit. Here we show the breakdown of conventional x-ray diffraction theory for the fundamental case of a “source”, consisting of a back-illuminated thin film in a circular aperture. When the conventional spontaneous x-ray scattering by atoms in the film is replaced at high incident intensity by stimulated resonant scattering, the film becomes the source of cloned photon twins and the diffraction pattern becomes self-focused beyond the diffraction limit. Furthermore, the case of cloned photon pairs is compared to and distinguished from entangled photonmore » pairs or biphotons.« less

  19. Beam diffraction by planar and parabolic reflectors

    NASA Astrophysics Data System (ADS)

    Suedan, Gibreel A.; Jull, Edward V.

    1991-04-01

    In the complex source point (CSP) technique, an omnidirectional source diffraction solution becomes that for a directive beam when the coordinates of the source position are given appropriate complex values. This is applied to include feed directivity in reflector edge diffraction. Solutions and numerical examples for planar strip and parabolic cylinder reflectors are given, including an offset parabolic reflector. The main beams of parabolic reflectors are calculated by aperture integration and the edge diffracted fields by uniform diffraction theory. In both cases, a complex source point feed in the near or far field of the reflector may be used in the pattern calculation, with improvements in accuracy in the lateral and spillover pattern lobes.

  20. Eyeglass. 1. Very large aperture diffractive telescopes.

    PubMed

    Hyde, R A

    1999-07-01

    The Eyeglass is a very large aperture (25-100-m) space telescope consisting of two distinct spacecraft, separated in space by several kilometers. A diffractive lens provides the telescope s large aperture, and a separate, much smaller, space telescope serves as its mobile eyepiece. Use of a transmissive diffractive lens solves two basic problems associated with very large aperture space telescopes; it is inherently launchable (lightweight, packagable, and deployable) it and virtually eliminates the traditional, very tight surface shape tolerances faced by reflecting apertures. The potential drawback to use of a diffractive primary (very narrow spectral bandwidth) is eliminated by corrective optics in the telescope s eyepiece; the Eyeglass can provide diffraction-limited imaging with either single-band (Deltalambda/lambda approximately 0.1), multiband, or continuous spectral coverage.

  1. Diffractive waveplates for long wave infrared

    NASA Astrophysics Data System (ADS)

    Ouskova, Elena; Roberts, David; Tabiryan, Nelson; Steeves, D. M.; Kimball, B. R.

    2017-05-01

    We report about developing long-wave infrared diffractive optical components based on liquid crystals. The components show high efficiency and high transparency for the 10.6 μm wavelength of CO2 laser beam.

  2. Eyeglass. 1. Very large aperture diffractive telescopes

    SciTech Connect

    Hyde, R.A.

    1999-07-01

    The Eyeglass is a very large aperture (25{endash}100-m) space telescope consisting of two distinct spacecraft, separated in space by several kilometers. A diffractive lens provides the telescope{close_quote}s large aperture, and a separate, much smaller, space telescope serves as its mobile eyepiece. Use of a transmissive diffractive lens solves two basic problems associated with very large aperture space telescopes; it is inherently launchable (lightweight, packagable, and deployable) it and virtually eliminates the traditional, very tight surface shape tolerances faced by reflecting apertures. The potential drawback to use of a diffractive primary (very narrow spectral bandwidth) is eliminated by corrective optics in the telescope{close_quote}s eyepiece; the Eyeglass can provide diffraction-limited imaging with either single-band ({Delta}{lambda}/{lambda}{approximately}0.1), multiband, or continuous spectral coverage. {copyright} 1999 Optical Society of America

  3. Two-Photon X-Ray Diffraction

    NASA Astrophysics Data System (ADS)

    Stöhr, J.

    2017-01-01

    The interference pattern of a circular photon source has long been used to define the optical diffraction limit. Here we show the breakdown of conventional x-ray diffraction theory for the fundamental case of a "source," consisting of a back-illuminated thin film in a circular aperture. When the conventional spontaneous x-ray scattering by atoms in the film is replaced at high incident intensity by stimulated resonant scattering, the film becomes the source of cloned photon twins and the diffraction pattern becomes self-focussed beyond the diffraction limit. The case of cloned x-ray biphotons is compared to and distinguished from the much studied case of entangled optical biphotons.

  4. Diffractive Optic Fluid Shear Stress Sensor

    NASA Technical Reports Server (NTRS)

    Wilson, D.; Scalf, J.; Forouhar, S.; Muller, R.; Taugwalder, F.; Gharib, M.; Fourguette, D.; Madarress, D.

    2000-01-01

    Light scattering off particles flowing through a two-slit inteference pattern can be used to measure the shear stress of the fluid. We have designed and fabricated a miniature diffractive optic sensor based on this principle.

  5. Nanostructured gradient-index antireflection diffractive optics.

    PubMed

    Chang, Chih-Hao; Dominguez-Caballero, Jose A; Choi, Hyungryul J; Barbastathis, George

    2011-06-15

    We describe the fabrication and characterization of a nanostructured diffractive element with near-zero reflection losses. In this element, subwavelength nanostructures emulating adiabatic index matching are integrated on the surface of a diffractive microstructure to suppress reflected diffraction orders. The fabricated silicon grating exhibits reflected efficiencies that are suppressed by 2 orders of magnitude over broad wavelength bands and wide incident angles. Theoretical models of the fabricated structure based on rigorous coupled-wave analysis and effective medium theory are in agreement with the experimental data. The proposed principles can be applied to improve the performance of any diffractive structures, potentially leading to more efficient Fresnel lenses, holographic elements, and integrated optical systems.

  6. Diffractive Optic Fluid Shear Stress Sensor

    NASA Technical Reports Server (NTRS)

    Wilson, D.; Scalf, J.; Forouhar, S.; Muller, R.; Taugwalder, F.; Gharib, M.; Fourguette, D.; Modarress, D.

    2000-01-01

    Light scattering off particles flowing through a two-slit interference pattern can be used to measure the shear stress of the fluid. We have designed and fabricated a miniature diffractive optic sensor based on this principle.

  7. X-ray Diffraction, Big and Small

    NASA Image and Video Library

    2012-10-30

    A conventional X-ray diffraction instrument left is the size of a large refrigerator, in contrast to the compact size of the Chemistry and Mineralogy CheMin instrument on NASA Curiosity rover top right.

  8. Electron backscatter diffraction: applications for nuclear materials.

    PubMed

    Medevielle; Hugon; Dugne

    1999-09-01

    The diffraction of electrons was first observed in 1928 by Kikuchi. The phenomenon results in the formation of characteristic diagrams of the crystalline lattice and the orientation of the phase. Backscattered electrons are diffracted by the different crystallographic planes (hkl) according to the Bragg angle thetab. These describe, by symmetry, two cones of axes normal to the diffracting plane. Information is collected on a phosphor screen, leading to the acquisition of a diffraction pattern called a Kikuchi diagram. Several improvements now give a wide range of applications such as phase identification (carbides or complex compounds in a (U,Zr,O) structure), analysis of materials interfaces (ZrO2/UO2), as well as solidification studies and local texture determination (molybdenum sheets). In these applications, EBSD, as a type of quantitative metallography, is a powerful tool.

  9. Two-Photon X-Ray Diffraction.

    PubMed

    Stöhr, J

    2017-01-13

    The interference pattern of a circular photon source has long been used to define the optical diffraction limit. Here we show the breakdown of conventional x-ray diffraction theory for the fundamental case of a "source," consisting of a back-illuminated thin film in a circular aperture. When the conventional spontaneous x-ray scattering by atoms in the film is replaced at high incident intensity by stimulated resonant scattering, the film becomes the source of cloned photon twins and the diffraction pattern becomes self-focussed beyond the diffraction limit. The case of cloned x-ray biphotons is compared to and distinguished from the much studied case of entangled optical biphotons.

  10. Diffraction-limited ultrabroadband terahertz spectroscopy

    NASA Astrophysics Data System (ADS)

    Baillergeau, M.; Maussang, K.; Nirrengarten, T.; Palomo, J.; Li, L. H.; Linfield, E. H.; Davies, A. G.; Dhillon, S.; Tignon, J.; Mangeney, J.

    2016-05-01

    Diffraction is the ultimate limit at which details of objects can be resolved in conventional optical spectroscopy and imaging systems. In the THz spectral range, spectroscopy systems increasingly rely on ultra-broadband radiation (extending over more 5 octaves) making a great challenge to reach resolution limited by diffraction. Here, we propose an original easy-to-implement wavefront manipulation concept to achieve ultrabroadband THz spectroscopy system with diffraction-limited resolution. Applying this concept to a large-area photoconductive emitter, we demonstrate diffraction-limited ultra-broadband spectroscopy system up to 14.5 THz with a dynamic range of 103. The strong focusing of ultrabroadband THz radiation provided by our approach is essential for investigating single micrometer-scale objects such as graphene flakes or living cells, and besides for achieving intense ultra-broadband THz electric fields.

  11. X-ray diffraction from rectangular slits.

    PubMed

    Le Bolloc'h, D; Livet, F; Bley, F; Schulli, T; Veron, M; Metzger, T H

    2002-07-01

    It is shown that for micrometre-sized beams the X-ray diffraction from slits is a source of strong parasitic background, even for slits of high quality. In order to illustrate this effect, the coherent diffraction from rectangular slits has been studied in detail. A large number of interference fringes with strong visibility have been observed using a single set of slits made of polished cylinders. For very small apertures, asymmetrical slits generate asymmetrical patterns. This pattern is calculated from the theory of electromagnetic field propagation and compared with experiment in the far-field regime. The use of guard slits to remove Fraunhofer diffraction from the beam-defining slits is treated theoretically. Numerical simulations yield the optimum aperture of the guard slits with respect to the distance to the primary slits. Diffraction theory is shown to be essential to understand how to reduce the background-to-signal ratio in high-resolution experiments.

  12. X-ray diffraction: instrumentation and applications.

    PubMed

    Bunaciu, Andrei A; Udriştioiu, Elena Gabriela; Aboul-Enein, Hassan Y

    2015-01-01

    X-ray diffraction (XRD) is a powerful nondestructive technique for characterizing crystalline materials. It provides information on structures, phases, preferred crystal orientations (texture), and other structural parameters, such as average grain size, crystallinity, strain, and crystal defects. X-ray diffraction peaks are produced by constructive interference of a monochromatic beam of X-rays scattered at specific angles from each set of lattice planes in a sample. The peak intensities are determined by the distribution of atoms within the lattice. Consequently, the X-ray diffraction pattern is the fingerprint of periodic atomic arrangements in a given material. This review summarizes the scientific trends associated with the rapid development of the technique of X-ray diffraction over the past five years pertaining to the fields of pharmaceuticals, forensic science, geological applications, microelectronics, and glass manufacturing, as well as in corrosion analysis.

  13. An Electronic Analog of the Diffraction Grating.

    ERIC Educational Resources Information Center

    MacLeod, A. M.

    1978-01-01

    Gives an outline description of electronic circuitry which is analogous to the optical diffraction grating or to crystals used in the Bragg reflection of X-rays or electron waves, and explains how to use it. (Author/GA)

  14. Self-referencing diffractive features for OVDs

    NASA Astrophysics Data System (ADS)

    Staub, Rene; Tompkin, Wayne R.

    2000-04-01

    We will show various diffractive features which are easy to verify and highly secure against attempts to counterfeit. These features are based on engineered surface relief structures which allow one to tailor the diffraction properties to obtain the desired effects. The security is based on complex diffraction structures rather than on complex image content, allowing the realization of relative simple feature designs, which are favorable from an ergonomic point of view. The unique properties of the engineered diffraction structures can be visualized, if an appropriate reference is provided, against which the observer can compare. We follow the idea that the optical effects in a well designed security feature must be interdependent in the sense of coherence or self- referencing. Various examples are presented, showing unique self-referencing first-line security features for document applications, which are clearly recognizable and easy to communicate. The presented effects are resilient against attempts to counterfeit by holographic techniques.

  15. Atomic resolution 3D electron diffraction microscopy

    SciTech Connect

    Miao, Jianwei; Ohsuna, Tetsu; Terasaki, Osamu; O'Keefe, Michael A.

    2002-03-01

    Electron lens aberration is the major barrier limiting the resolution of electron microscopy. Here we describe a novel form of electron microscopy to overcome electron lens aberration. By combining coherent electron diffraction with the oversampling phasing method, we show that the 3D structure of a 2 x 2 x 2 unit cell nano-crystal (framework of LTA [Al12Si12O48]8) can be ab initio determined at the resolution of 1 Angstrom from a series of simulated noisy diffraction pattern projections with rotation angles ranging from -70 degrees to +70 degrees in 5 degrees increments along a single rotation axis. This form of microscopy (which we call 3D electron diffraction microscopy) does not require any reference waves, and can image the 3D structure of nanocrystals, as well as non-crystalline biological and materials science samples, with the resolution limited only by the quality of sample diffraction.

  16. An Electronic Analog of the Diffraction Grating.

    ERIC Educational Resources Information Center

    MacLeod, A. M.

    1978-01-01

    Gives an outline description of electronic circuitry which is analogous to the optical diffraction grating or to crystals used in the Bragg reflection of X-rays or electron waves, and explains how to use it. (Author/GA)

  17. Cold Nuclear Matter Effects on Heavy Quark Production in Relativistic Heavy Ion Collisions

    NASA Astrophysics Data System (ADS)

    Durham, John Matthew

    2011-12-01

    The experimental collaborations at the Relativistic Heavy Ion Collider (RHIC) have established that dense nuclear matter with partonic degrees of freedom is formed in collisions of heavy nuclei at 200 GeV. Information from heavy quarks has given significant insight into the dynamics of this matter. Charm and bottom quarks are dominantly produced by gluon fusion in the early stages of the collision, and thus experience the complete evolution of the medium. The production baseline measured in p + p collisions can be described by fixed order plus next to leading log perturbative QCD calculations within uncertainties. In central Au+Au collisions, suppression has been measured relative to the yield in p + p scaled by the number of nucleon-nucleon collisions, indicating a significant energy loss by heavy quarks in the medium. The large elliptic flow amplitude v2 provides evidence that the heavy quarks flow along with the lighter partons. The suppression and elliptic flow of these quarks are in qualitative agreement with calculations based on Langevin transport models that imply a viscosity to entropy density ratio close to the conjectured quantum lower bound of 1/4pi. However, a full understanding of these phenomena requires measurements of cold nuclear matter (CNM) effects, which should be present in Au+Au collisions but are difficult to distinguish experimentally from effects due to interactions with the medium. This thesis presents measurements of electrons at midrapidity from the decays of heavy quarks produced in d+Au collisions at RHIC. A significant enhancement of these electrons is seen at a transverse momentum below 5 GeV/c, indicating strong CNM effects on charm quarks that are not present for lighter quarks. A simple model of CNM effects in Au+Au collisions suggests that the level of suppression in the hot nuclear medium is comparable for all quark flavors.

  18. The early development of neutron diffraction: science in the wings of the Manhattan Project

    SciTech Connect

    Mason, T. E. Gawne, T. J.; Nagler, S. E.; Nestor, M. B.; Carpenter, J. M.

    2013-01-01

    Early neutron diffraction experiments performed in 1944 using the first nuclear reactors are described. Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan Project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurement of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor. Subsequent work by Wollan and Clifford G. Shull, who joined Wollan’s group at Oak Ridge in 1946, laid the foundations for widespread application of neutron diffraction as an important research tool.

  19. Simulating interference and diffraction in instructional laboratories

    NASA Astrophysics Data System (ADS)

    Maurer, L.

    2013-03-01

    Studieshave shown that standard lectures and instructional laboratory experiments are not effective at teaching interference and diffraction. In response, the author created an interactive computer program that simulates interference and diffraction effects using the finite difference time domain method. The software allows students to easily control, visualize and quantitatively measure the effects. Students collected data from simulations as part of their laboratory exercise, and they performed well on a subsequent quiz, showing promise for this approach.

  20. [X-ray diffraction spectrum of heroin].

    PubMed

    Hu, X; Kan, J; Yuan, B

    1999-06-01

    In this paper, practical measured X-ray diffraction spectra of heroin and opium are given and the parameters of each diffraction peak of the heroin are listed. The heroin belongs to orthorhombic crystal system; the basic vectors of the primitive cell are: a = 8.003, b = 14.373, c = 16.092 x 10(-10) m. As compared with the standard spectra of pure heroin and sucrose, the main doped additive checked by us, is sugar affirmatively.