Science.gov

Sample records for probing exotic nuclear

  1. Fundamental nucleon-nucleon interaction: probing exotic nuclear structure using GEANIE at LANCE/WNR

    SciTech Connect

    Bernstein, L

    2000-02-25

    The initial goal of this project was to study the in-medium nucleon-nucleon interaction by testing the fundamental theory of nuclear structure, the shell model, for nuclei between {sup 8}Zr and {sup 100}Sn. The shell model predicts that nuclei with ''magic'' (2,8,20,28,40,50, and 82) numbers of protons or neutrons form closed shells in the same fashion as noble gas atoms [may49]. A ''doubly magic'' nucleus with a closed shell of both protons and neutrons has an extremely simple structure and is therefore ideal for studying the nucleon-nucleon interaction. The shell model predicts that doubly magic nuclei will be spherical and that they will have large first-excited-state energies ({approx} 1 to 3 MeV). Although the first four doubly-magic nuclei exhibit this behavior, the N = Z = 40 nucleus, {sup 80}Zr, has a very low first-excited-state energy (290 keV) and appears to be highly deformed. This breakdown is attributed to the small size of the shell gap at N = Z = 40. If this description is accurate, then the N = Z = 50 doubly magic nucleus, {sup 100}Sn, will exhibit ''normal'' closed-shell behavior. The unique insight provided by doubly-magic nuclei from {sup 80}Zr to {sup 100}Sn has made them the focus of tremendous interest in the nuclear structure community. However, doubly-magic nuclei heavier than {sup 56}Ni become increasingly difficult to form due to the coulomb repulsion between the protons which favors the formation of neutron-rich nuclei. The coulomb repulsion creates a ''proton drip-line'' beyond which the addition of any additional bound protons is energetically impossible. The drip line renders the traditional experimental technique used in their formation, the heavy-ion reaction, less than ideal as a method of forming doubly-magic nuclei beyond {sup 80}Zr. The result has been a lack of an new spectroscopic information on doubly magic nuclei in more than a decade [lis87]. Furthermore, uncertainties in reaction dynamics modeling made it difficult for the

  2. Probing the exotic structure of 8B by its elastic scattering and breakup reaction on nuclear targets

    NASA Astrophysics Data System (ADS)

    Lukyanov, V. K.; Kadrev, D. N.; Zemlyanaya, E. V.; Lukyanov, K. V.; Antonov, A. N.; Gaidarov, M. K.; Spasova, K.

    2017-02-01

    The structure of the exotic 8B nucleus is studied by means of elastic scattering, as well as its breakup on nuclear targets. We present microscopic calculations of the optical potentials (OPs) and cross sections of elastic scattering of 8B on 12C, 58Ni, and 208Pb targets at energies 20 < E < 170 MeV. The density distributions of 8B obtained within the variational Monte Carlo (VMC) model and the three-cluster model (3CM) are used to construct the potentials. The real part of the hybrid OP is calculated using the folding model with the direct and exchange terms included, while the imaginary part is obtained on the base of the high-energy approximation (HEA) and also taken to be equal to the microscopic real part of the OP. In this model the only free parameters are the depths of the real and imaginary parts of OP obtained by fitting the elastic scattering experimental data. A dependence of their values on the model density of 8 B is found. In addition, the cluster model, in which 8B consists of a p-halo and the 7 Be core, is applied to calculate the breakup cross sections of the 8B nucleus on 9Be, 12C, and 197Au targets, as well as momentum distributions of 7Be fragments, and a comparison with the existing experimental data is made.

  3. Unified approach to nuclear densities from exotic atoms

    NASA Astrophysics Data System (ADS)

    Friedman, E.

    2009-09-01

    Parameters of nuclear density distributions are derived from least-squares fits to strong interaction observables in exotic atoms. Global analyses of antiprotonic and pionic atoms show reasonably good agreement between the two types of probes regarding the average behaviour of root-mean-square radii of the neutron distributions. Apparent conflict regarding the shape of the neutron distribution is attributed to different radial sensitivities of these two probes.

  4. Probing Exotic Physics With Supernova Neutrinos

    SciTech Connect

    Kelso, Chris; Hooper, Dan

    2010-09-01

    Future galactic supernovae will provide an extremely long baseline for studying the properties and interactions of neutrinos. In this paper, we discuss the possibility of using such an event to constrain (or discover) the effects of exotic physics in scenarios that are not currently constrained and are not accessible with reactor or solar neutrino experiments. In particular, we focus on the cases of neutrino decay and quantum decoherence. We calculate the expected signal from a core-collapse supernova in both current and future water Cerenkov, scintillating, and liquid argon detectors, and find that such observations will be capable of distinguishing between many of these scenarios. Additionally, future detectors will be capable of making strong, model-independent conclusions by examining events associated with a galactic supernova's neutronization burst.

  5. Probing the Evolution of the Shell Structures in Exotic Nuclei

    SciTech Connect

    De Angelis, Giacomo

    2008-11-11

    Magic numbers are a key feature in finite Fermion systems since they are strongly related to the underlying mean field. The size of the shell gaps and their evolution far from stability can be linked to the shape and symmetry of the nuclear mean field. Moreover the study of nuclei with large neutron/proton ratio allow to probe the density dependence of the effective interaction. Changes of the nuclear density and size in nuclei with increasing N/Z ratios are expected to lead to different nuclear symmetries and excitations. In this contribution I will discuss some selected examples which show the big potential of stable beams and of binary reactions for the study of the properties of the neutron-rich nuclear many body systems.

  6. Spes: Exotic Beams for Nuclear Physics Studies

    NASA Astrophysics Data System (ADS)

    Andrighetto, Alberto; Manzolaro, Mattia; Corradetti, Stefano; Scarpa, Daniele; Vasquez, Jesu; Rossignoli, Massimo; Monetti, Alberto; Calderolla, Michele; Prete, Gianfranco

    2014-02-01

    The SPES project at Laboratori di Legnaro of INFN (Italy) is concentrating on the production of neutron-rich radioactive nuclei for nuclear physics experiments using uranium fission at a rate of 1013 fission/s. The emphasis on neutron-rich isotopes is justified by the fact that this vast territory has been little explored. The Radioactive Ion Beam (RIB) will be produced by the ISOL technique using proton induced fission on a direct target of UCx. The most critical element of the SPES project is the Multi-Foil Direct Target. Up to the present time, the proposed target represents an innovation in terms of its capability to sustain the primary beam power. This talk will present the status of the project financed by INFN, which is actually in the construction phase at Legnaro. In particular, developments related to the target and the ion-source activities using the surface ion source, plasma ion source, and laser ion source techniques will be reported.

  7. Masses of exotic calcium isotopes pin down nuclear forces.

    PubMed

    Wienholtz, F; Beck, D; Blaum, K; Borgmann, Ch; Breitenfeldt, M; Cakirli, R B; George, S; Herfurth, F; Holt, J D; Kowalska, M; Kreim, S; Lunney, D; Manea, V; Menéndez, J; Neidherr, D; Rosenbusch, M; Schweikhard, L; Schwenk, A; Simonis, J; Stanja, J; Wolf, R N; Zuber, K

    2013-06-20

    The properties of exotic nuclei on the verge of existence play a fundamental part in our understanding of nuclear interactions. Exceedingly neutron-rich nuclei become sensitive to new aspects of nuclear forces. Calcium, with its doubly magic isotopes (40)Ca and (48)Ca, is an ideal test for nuclear shell evolution, from the valley of stability to the limits of existence. With a closed proton shell, the calcium isotopes mark the frontier for calculations with three-nucleon forces from chiral effective field theory. Whereas predictions for the masses of (51)Ca and (52)Ca have been validated by direct measurements, it is an open question as to how nuclear masses evolve for heavier calcium isotopes. Here we report the mass determination of the exotic calcium isotopes (53)Ca and (54)Ca, using the multi-reflection time-of-flight mass spectrometer of ISOLTRAP at CERN. The measured masses unambiguously establish a prominent shell closure at neutron number N = 32, in excellent agreement with our theoretical calculations. These results increase our understanding of neutron-rich matter and pin down the subtle components of nuclear forces that are at the forefront of theoretical developments constrained by quantum chromodynamics.

  8. Nuclear-structure studies of exotic nuclei with MINIBALL

    NASA Astrophysics Data System (ADS)

    Butler, P. A.; Cederkall, J.; Reiter, P.

    2017-04-01

    High-resolution γ-ray spectroscopy has been established at ISOLDE for nuclear-structure and nuclear-reaction studies with reaccelerated radioactive ion beams provided by the REX-ISOLDE facility. The MINIBALL spectrometer comprises 24 six-fold segmented, encapsulated high-purity germanium crystals. It was specially designed for highest γ-ray detection efficiency which is advantageous for low-intensity radioactive ion beams. The MINIBALL array has been used in numerous Coulomb-excitation and transfer-reaction experiments with exotic ion beams of energies up to 3 MeV A–1. The physics case covers a wide range of topics which are addressed with beams ranging from neutron-rich magnesium isotopes up to heavy radium isotopes. In the future the HIE-ISOLDE will allow the in-beam γ-ray spectroscopy program to proceed with higher secondary-beam intensity, higher beam energy and better beam quality.

  9. Use of exotic nuclear beams for nuclear structure studies

    SciTech Connect

    Sugimoto, K.

    1984-10-01

    Possible experiments are discussed for nuclear structure studies using, as secondary beams, projectile fragments produced by high-energy heavy-ion collisions. They are, specifically, (a) determination of nuclear sizes from measurements of the total interaction cross sections of nucleus-nucleus collisions, and (b) determination of static electromagnetic moments, ..mu..'s and Q's, of short-lived ..beta..-radioactive nuclei. 9 references.

  10. Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation

    NASA Astrophysics Data System (ADS)

    Yamanaka, N.; Sahoo, B. K.; Yoshinaga, N.; Sato, T.; Asahi, K.; Das, B. P.

    2017-03-01

    The current status of electric dipole moments of diamagnetic atoms which involves the synergy between atomic experiments and three different theoretical areas, i.e. particle, nuclear and atomic, is reviewed. Various models of particle physics that predict CP violation, which is necessary for the existence of such electric dipole moments, are presented. These include the standard model of particle physics and various extensions of it. Effective hadron level combined charge conjugation (C) and parity (P) symmetry violating interactions are derived taking into consideration different ways in which a nucleon interacts with other nucleons as well as with electrons. Nuclear structure calculations of the CP-odd nuclear Schiff moment are discussed using the shell model and other theoretical approaches. Results of the calculations of atomic electric dipole moments due to the interaction of the nuclear Schiff moment with the electrons and the P and time-reversal (T) symmetry violating tensor-pseudotensor electron-nucleus are elucidated using different relativistic many-body theories. The principles of the measurement of the electric dipole moments of diamagnetic atoms are outlined. Upper limits for the nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained combining the results of atomic experiments and relativistic many-body theories. The coefficients for the different sources of CP violation have been estimated at the elementary particle level for all the diamagnetic atoms of current experimental interest and their implications for physics beyond the standard model is discussed. Possible improvements of the current results of the measurements as well as quantum chromodynamics, nuclear and atomic calculations are suggested.

  11. PREFACE: International Symposium on Exotic Nuclear Structure From Nucleons (ENSFN 2012)

    NASA Astrophysics Data System (ADS)

    Honma, Michio; Utsuno, Yutaka; Shimizu, Noritaka

    2013-07-01

    The International Symposium on 'Exotic Nuclear Structure From Nucleons (ENSFN2012)' was held at the Koshiba Hall, the University of Tokyo, Japan, from October 10th to 12th, 2012. This symposium was supported by RIKEN Nishina Center (RNC) and the Center for Nuclear Study (CNS), University of Tokyo. This symposium was devoted to discussing recent achievement and perspectives in the structure of exotic nuclei from the viewpoint of the nuclear force. The following subjects were covered in this symposium from both theoretical and experimental sides: Evolution of shell structure and collectivity in exotic nuclei Ab-initio theory and its application to exotic nuclei Advancement in large-scale nuclear-structure calculations Effective Hamiltonian and energy density functional Spin-isospin responses New aspects of two- and three-body forces Impact on nuclear astrophysics Emphasis was placed on the development of large-scale nuclear-structure calculations and the new experimental information on exotic nuclei. Around 80 participants attended this symposium and we enjoyed 37 excellent invited talks and 9 selected oral presentations. A special talk was presented to celebrate the 60th birthday of professor Takaharu Otsuka, who has made invaluable contribution to the progress in the fields covered in this symposium. The organizing committee consisted of T Abe (Tokyo), M Honma (Aizu; chair), N Itagaki (YITP, Kyoto), T Mizusaki (Senshu), T Nakatsukasa (RIKEN), H Sakurai (Tokyo/RIKEN), N Shimizu (CNS, Tokyo; scientific secretary), S Shimoura (CNS, Tokyo), Y Utsuno (JAEA/CNS, Tokyo; scientific secretary). Finally, we would like to thank all the speakers and the participants as well as the other organizers for their contributions which made the symposium very successful. Michio Honma, Yutaka Utsuno and Noritaka Shimizu Editors Tokyo, April 2013 Sponsors logo1 Sponsors logo2 The PDF also contains the conference program.

  12. Studies of exotic nuclear reactions at the RESOLUT facility

    NASA Astrophysics Data System (ADS)

    Wiedenhoever, Ingo

    2016-09-01

    The RESOLUT facility at Florida State University's accelerator laboratory produces beams of short-lived nuclei using the in-flight method. Beams such as 6He, 7Be, 8Li, 8B, 17F, 19O, 18Ne and 25Al have been successfully used in experiments. The facility has been used to develop innovative experimental techniques, such as the low-energy neutron detector RESONEUT, and the active-target detector ANASEN, which has been developed as a collaboration between FSU and LSU. These detectors have been employed in direct and indirect reaction measurements with impact on astrophysics. An Indiana-University led campaign studying fusion cross sections of exotic nuclei at RESOLUT has also been successful. The results from these three recent RIB campaigns at RESOLUT will be summarized. This work was supported by NSF under Grants Nos. PHY-1401574, PHY-0820941 and PHY-1126345 and by DOE under Grant Nos. DE-FG02-02ER41220, DE-FG02-88ER-40404 and DE-FG02-96ER40978.

  13. Ab Initio Calculations Of Nuclear Reactions And Exotic Nuclei

    SciTech Connect

    Quaglioni, S.

    2014-05-05

    Our ultimate goal is to develop a fundamental theory and efficient computational tools to describe dynamic processes between nuclei and to use such tools toward supporting several DOE milestones by: 1) performing predictive calculations of difficult-to-measure landmark reactions for nuclear astrophysics, such as those driving the neutrino signature of our sun; 2) improving our understanding of the structure of nuclei near the neutron drip line, which will be the focus of the DOE’s Facility for Rare Isotope Beams (FRIB) being constructed at Michigan State University; but also 3) helping to reveal the true nature of the nuclear force. Furthermore, these theoretical developments will support plasma diagnostic efforts at facilities dedicated to the development of terrestrial fusion energy.

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

    SciTech Connect

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

    2009-12-15

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

  15. Probing Cold Dense Nuclear Matter

    SciTech Connect

    Subedi, Ramesh; Shneor, R.; Monaghan, Peter; Anderson, Bryon; Aniol, Konrad; Annand, John; Arrington, John; Benaoum, Hachemi; Benmokhtar, Fatiha; Bertozzi, William; Boeglin, Werner; Chen, Jian-Ping; Choi, Seonho; Cisbani, Evaristo; Craver, Brandon; Frullani, Salvatore; Garibaldi, Franco; Gilad, Shalev; Gilman, Ronald; Glamazdin, Oleksandr; Hansen, Jens-Ole; Higinbotham, Douglas; Holmstrom, Timothy; Ibrahim, Hassan; Igarashi, Ryuichi; De Jager, Cornelis; Jans, Eddy; Jiang, Xiaodong; Kaufman, Lisa; Kelleher, Aidan; Kolarkar, Ameya; Kumbartzki, Gerfried; LeRose, John; Lindgren, Richard; Liyanage, Nilanga; Margaziotis, Demetrius; Markowitz, Pete; Marrone, Stefano; Mazouz, Malek; Meekins, David; Michaels, Robert; Moffit, Bryan; Perdrisat, Charles; Piasetzky, Eliazer; Potokar, Milan; Punjabi, Vina; Qiang, Yi; Reinhold, Joerg; Ron, Guy; Rosner, Guenther; Saha, Arunava; Sawatzky, Bradley; Shahinyan, Albert; Sirca, Simon; Slifer, Karl; Solvignon, Patricia; Sulkosky, Vince; Sulkosky, Vincent; Sulkosky, Vince; Sulkosky, Vincent; Urciuoli, Guido; Voutier, Eric; Watson, John; Weinstein, Lawrence; Wojtsekhowski, Bogdan; Wood, Stephen; Zheng, Xiaochao; Zhu, Lingyan

    2008-06-01

    The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars.

  16. Accuracy of Determination of the Parameters of Exotic Nuclei Nuclear Density Distributions in the Glauber Model

    NASA Astrophysics Data System (ADS)

    Rueter, Keiti; Novikov, Ivan

    2016-09-01

    Parameters of a nuclear density distribution for an exotic nuclei with halo or skin structures can be determined from the experimentally measure interaction cross-section. In the presented work, to extract parameters for a halo and core, we compare experimental data on interaction cross section with reaction cross-sections calculated using expressions obtained in the Glauber Model and its optical approximation. These calculations are performed using Markov Chain Monte Carlo algorithm. In addition, we discuss the accuracy of the Monte Carlo approach to calculating the interaction and reaction cross-sections. The dependence of the accuracy of the density parameters of various exotic nuclei on the ``quality'' of the random numbers chains (here, ``quality'' is defined by lag-1 autocorrelation time of a sequence of random numbers) is obtained for the Gaussian density distribution for a core and the Gaussian density distribution for a halo. KY NSF EPSCoR Research Scholars Program.

  17. The influence of nuclear deformations on the exotic cluster decay half-lives

    NASA Astrophysics Data System (ADS)

    Soylu, A.; Bayrak, O.; Evlice, S.

    2015-04-01

    We systematically study the investigation of the influence of nuclear deformations of the cluster and daughter nuclei on the exotic cluster decay half-lives of heavy nuclei by the WKB method and the Bohr-Sommerfeld quantization condition. Even if the deformations of both cluster and daughter in the half-live values of cluster decays improve the results, considering the deformation of clusters is more efficient than the deformation of daughter for the heavy cluster decay half-live calculations. Moreover, taking into account of angle orientations of daughter and cluster provides a positive contributions to the results as well. The results would be useful for experimental researches in half-lives of exotic decays of some heavy nuclei and radium isotopes.

  18. Probing nuclear matter with jet conversions

    SciTech Connect

    Liu, W.; Fries, R. J.

    2008-05-15

    We discuss the flavor of leading jet partons as a valuable probe of nuclear matter. We point out that the coupling of jets to nuclear matter naturally leads to an alteration of jet chemistry even at high transverse momentum p{sub T}. In particular, quantum chromodynamics (QCD) jets coupling to a chemically equilibrated quark gluon plasma in nuclear collisions will lead to hadron ratios at high transverse momentum p{sub T} that can differ significantly from their counterparts in p+p collisions. Flavor measurements could complement energy loss as a way to study interactions of hard QCD jets with nuclear matter. Roughly speaking they probe the inverse mean free path 1/{lambda} while energy loss probes the average squared momentum transfer {mu}{sup 2}/{lambda}. We present some estimates for the rate of jet conversions in a consistent Fokker-Planck framework and their impact on future high-p{sub T} identified hadron measurements at RHIC and LHC. We also suggest some novel observables to test flavor effects.

  19. Scrutinizing Exotic Cosmological Models Using ESSENCE Supernova Data Combined With Other Cosmological Probes

    SciTech Connect

    Davis, Tamara M.; Mortsell, E.; Sollerman, J.; Becker, A.C.; Blondin, S.; Challis, P.; Clocchiatti, A.; Filippenko, A.V.; Foley, R.J.; Garnavich, P.M.; Jha, S.; Krisciunas, K.; Kirshner, R.P.; Leibundgut, B.; Li, W.; Matheson, T.; Miknaitis, G.; Pignata, G.; Rest, A.; Riess, A.G.; Schmidt, B.P.; /Bohr Inst. /Stockholm U. /Washington U., Seattle, Astron. Dept. /Harvard-Smithsonian Ctr. Astrophys. /Chile U., Catolica /UC, Berkeley, Astron. Dept. /Notre Dame U. /KIPAC, Menlo Park /Texas A-M /European Southern Observ. /NOAO, Tucson /Fermilab /Cerro-Tololo InterAmerican Obs. /Baltimore, Space Telescope Sci. /Johns Hopkins U. /Res. Sch. Astron. Astrophys., Weston Creek /Harvard U. /Inst. Astron., Honolulu

    2007-01-25

    The first cosmological results from the ESSENCE supernova survey (Wood-Vasey et al. 2007) are extended to a wider range of cosmological models including dynamical dark energy and non-standard cosmological models. We fold in a greater number of external data sets such as the recent Higher-z release of high-redshift supernovae (Riess et al. 2007) as well as several complementary cosmological probes. Model comparison statistics such as the Bayesian and Akaike information criteria are applied to gauge the worth of models. These statistics favor models that give a good fit with fewer parameters. Based on this analysis, the preferred cosmological model is the flat cosmological constant model, where the expansion history of the universe can be adequately described with only one free parameter describing the energy content of the universe. Amongst the more exotic models that provide good fits to the data, we note a preference for models whose best-fit parameters reduce them to the cosmological constant model.

  20. 21 CFR 892.1320 - Nuclear uptake probe.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nuclear uptake probe. 892.1320 Section 892.1320...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1320 Nuclear uptake probe. (a) Identification. A nuclear uptake probe is a device intended to measure the amount of radionuclide taken up by...

  1. 21 CFR 892.1320 - Nuclear uptake probe.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nuclear uptake probe. 892.1320 Section 892.1320...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1320 Nuclear uptake probe. (a) Identification. A nuclear uptake probe is a device intended to measure the amount of radionuclide taken up by...

  2. 21 CFR 892.1320 - Nuclear uptake probe.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nuclear uptake probe. 892.1320 Section 892.1320...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1320 Nuclear uptake probe. (a) Identification. A nuclear uptake probe is a device intended to measure the amount of radionuclide taken up by...

  3. 21 CFR 892.1320 - Nuclear uptake probe.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nuclear uptake probe. 892.1320 Section 892.1320...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1320 Nuclear uptake probe. (a) Identification. A nuclear uptake probe is a device intended to measure the amount of radionuclide taken up by...

  4. 21 CFR 892.1320 - Nuclear uptake probe.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nuclear uptake probe. 892.1320 Section 892.1320...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1320 Nuclear uptake probe. (a) Identification. A nuclear uptake probe is a device intended to measure the amount of radionuclide taken up by...

  5. Nuclear Incompressibility and the Asymmetry Term: Implications for Astrophysics and Physics with Exotic Nuclei

    SciTech Connect

    Fujiwara, M.

    2010-06-01

    The compressional-mode giant resonances, the isoscalar giant monopole resonance (GMR) and the isoscalar giant dipole resonance (ISGDR), in various isotopes have been investigated using inelastic scattering of 400-MeV alpha-particles at extremely forward angles, including 0 deg. Recently, the centroid energies of the giant monopole resonance (GMR) in the Sn isotope region are found to be significantly lower than the theoretical predictions. In addition, based on the GMR results, the asymmetry-term in the nuclear incompressibility has been determined as K{sub t}au = -550+-100 MeV. Constraints on interactions employed in nuclear structure calculations are discussed on the basis of the experimentally values for K{sub i}nfinity and K{sub t}au. The combination of these two values gives stringent constraints on the interactions used for nuclear structure calculations and for formations of equation of state (EOS) of nuclear matter. A short review of the current status of the experimental studies on the compressional-mode giant resonances is given, and a possible new experiment for astrophysics and physics with exotic nuclei is suggested.

  6. Universal correlations of nuclear observables and the structure of exotic nuclei

    SciTech Connect

    Casten, R.F.; Zamfir, N.V. |||

    1996-12-31

    Despite the apparent complexity of nuclear structural evolution, recent work has shown a remarkable underlying simplicity that is unexpected, global, and which leads to new signatures for structure based on the easiest-to-obtain data. As such they will be extremely valuable for use in the experiments with low intensity radioactive beams. Beautiful correlations based either on extrinsic variables such as N{sub p}N{sub n} or the P-factor or correlations between collective observables themselves have been discovered. Examples to be discussed include a tri-partite classification of structural evolution, leading to a new paradigm that discloses certain specific classes of nuclei, universal trajectories for B(E2: w{sub 1}{sup +} {r_arrow} 0{sub 1}{sup +}) values and their use in extracting hexadecapole deformations from this observable alone, the use of these B(E2) values to identify shell gaps and magic numbers in exotic nuclei, the relationship of {beta} and {gamma} deformations, and single nucleon separation energies. Predictions for nuclei far off stability by interpolation will also be discussed.

  7. Simulation of nuclear quadrupole resonance for sensor probe optimization.

    PubMed

    Shinohara, Junichiro; Sato-Akaba, Hideo; Itozaki, Hideo

    2012-01-01

    A simulation method to estimate the detection efficiency of nuclear quadrupole resonance (NQR) was proposed for optimizing a sensing probe operating at radio frequencies (RFs). It first calculates the transmitted magnetic field from the probe coil to the target sample. The nuclei make quadrupole resonance by it. We considered this nonlinear reaction to estimate NQR emission by the nuclei. Then the received NQR signal intensity from the sample at the probe coil. We calculated the efficiency by testing two different probe types (solenoid and gradiometer) and by changing the relative positions of the probe and sample. The simulation results were in good agreement with the experimental results.

  8. Exotic Nuclei

    SciTech Connect

    Galindo-Uribarri, Alfredo {nmn}

    2010-01-01

    Current experimental developments on the study of exotic nuclei far from the valley of stability are discussed. I start with general aspects related to the production of radioactive beams followed by the description of some of the experimental tools and specialized techniques for studies in reaction spectroscopy, nuclear structure research and nuclear applications with examples from selected topical areas with which I have been involved. I discuss some of the common challenges faced in Accelerator Mass Spectrometry (AMS) and Radioactive Ion Beam (RIB) science.

  9. A novel probe of chiral restoration in nuclear medium

    NASA Astrophysics Data System (ADS)

    Gubler, Philipp; Kunihiro, Teiji; Lee, Su Houng

    2017-04-01

    We propose measuring the mass shift and width broadening of the f1 (1285) meson together with those of the ω from a nuclear target as a means to experimentally probe the partial restoration of chiral symmetry inside the nuclear matter. The relation between the order parameter of chiral symmetry and the difference in the correlation functions of the f1 (1285) current and the ω current is discussed in the limit where the disconnected diagrams are neglected. A QCD sum rule analysis of the f1 (1285) meson mass leads to about 100 MeV attraction in nuclear matter, which can be probed in future experiments.

  10. Nuclear structure studies with intermediate energy probes

    SciTech Connect

    Lee, T.S.H.

    1993-10-01

    Nuclear structure studies with pions are reviewed. Results from a recent study of 1 p-shell nuclei using (e,e{prime}), ({pi}, {pi}{prime}), and ({gamma},{pi}) reactions are reported. Future nuclear structure studies with GeV electrons at CEBAF are also briefly discussed.

  11. Probing nuclear structure of {sup 124}Xe

    SciTech Connect

    Saha, B.; Dewald, A.; Moeller, O.; Peusquens, R.; Jessen, K.; Fitzler, A.; Klug, T.; Tonev, D.; Brentano, P. von; Jolie, J.; Gall, B.J.P.; Petkov, P.

    2004-09-01

    Excited states in {sup 124}Xe were populated in the fusion-evaporation reaction {sup 110}Pd({sup 18}O,4n){sup 124}Xe at a beam energy of 80 MeV. A recoil distance measurement using the Euroball spectrometer in Strasbourg and the Cologne plunger was performed. Altogether 19 lifetimes of excited states in six different bands were determined using gated spectra only, in order to avoid problems related to feeding. The measured B(E2) values were used to derive the nuclear deformation of {sup 124}Xe and the interaction of the ground state band with two s bands. Two sd-IBM-1 calculations with two Hamiltonians of different complexities were performed, which show a good agreement with the measured B(E2) values in the ground state band and the quasi-{gamma} band. The deduced B(M1) values for the regular M1 band show the behavior expected for magnetic rotation. However, it is also shown that these experimental B(M1) values can be described on the basis of a rotational band as well.

  12. Studies on Nuclear Astrophysics and Exotic Structure at the Low-Energy RI Beam Facility CRIB

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.; Kahl, D.; Hayakawa, S.; Sakaguchi, Y.; Nakao, T.; Wakabayashi, Y.; Hashimoto, T.; Teranishi, T.; Kubono, S.; Cherubini, S.; Mazzocco, M.; Signorini, C.; Gulino, M.; Di Pietro, A.; Figuera, P.; La Cognata, M.; Lattuada, M.; Spitaleri, C.; Torresi, D.; Lee, P. S.; Lee, C. S.; Komatsubara, T.; Iwasa, N.; Okoda, Y.; Pierroutsakou, D.; Parascandolo, C.; La Commara, M.; Strano, E.; Boiano, C.; Boiano, A.; Manea, C.; Sánchez-Benítez, A. M.; Miyatake, H.; Watanabe, Y. X.; Ishiyama, H.; Jeong, S. C.; Imai, N.; Hirayama, Y.; Kimura, S.; Mukai, M.; Kim, Y. H.; Lin, C. J.; Jia, H. M.; Yan, L.; Yang, Y. Y.; Kawabata, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. N.

    Studies on nuclear astrophysics, resonant structure, and nuclear reaction are going on at CRIB (CNS Radioactive Ion Beam separator), a low-energy RI beam separator operated by Center for Nuclear Study (CNS), the University of Tokyo. Two major methods used at CRIB to study nuclear reactions of astrophysical relevance are the resonant scattering, and direct measurements of (α,p) reactions using a thick-gas target. Several experiments for decay measurements and reaction mechanism are also performed using low-energy RI beams at CRIB. Some of the results from recent experiments at CRIB are discussed.

  13. Exotic neutron-rich medium-mass nuclei with realistic nuclear forces

    NASA Astrophysics Data System (ADS)

    Tsunoda, Naofumi; Otsuka, Takaharu; Shimizu, Noritaka; Hjorth-Jensen, Morten; Takayanagi, Kazuo; Suzuki, Toshio

    2017-02-01

    We present the first application of the newly developed extended Kuo-Krenciglowa (EKK) theory of the effective nucleon-nucleon interaction to shell-model studies of exotic nuclei, including those where conventional approaches with fitted interactions encounter difficulties. This EKK theory enables us to derive an interaction that is suitable for several major shells (s d +p f in this work). By using such an effective interaction obtained from the Entem-Machleidt QCD-based χ N3LO interaction and the Fujita-Miyazawa three-body force, the energies, E 2 properties, and spectroscopic factors of low-lying states of neutron-rich Ne, Mg, and Si isotopes are nicely described, as the first shell-model description of the "island of inversion" without fit of the interaction. The long-standing question as to how particle-hole excitations occur across the s d -p f magic gap is clarified with distinct differences from the conventional approaches. The shell evolution is shown to appear similarly to earlier studies.

  14. Nuclear Structure Studies of Exotic Nuclei with Radioactive Ion Beams A Final Report

    SciTech Connect

    Winger, Jeff Allen

    2016-04-21

    Beta-decay spectroscopy provides important information on nuclear structure and properties needed to understand topics as widely varied as fundamental nuclear astrophysics to applied nuclear reactor design. However, there are significant limitations of our knowledge due to an inability to experimentally measure everything. Therefore, it is often necessary to rely on theoretical calculations which need to be vetted with experimental results. The focus of this report will be results from experimental research performed by the Principal Investigator (PI) and his research group at Mississippi State University in which the group played the lead role in proposing, implementing, performing and analyzing the experiment. This research was carried out at both the National Superconduction Cyclotron Laboratory (NSCL) at Michigan State University and the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. The primary emphasis of the research was the use of \\bdec spectroscopy as a tool to understand the evolution of nuclear structure in neutron-rich nuclei which could then be applied to improve theory and to increase the overall knowledge of nuclear structure.

  15. Determination of hyperfine fields orientation in nuclear probe techniques

    NASA Astrophysics Data System (ADS)

    Szymański, K.; Olszewski, W.; Satuła, D.; Gawryluk, D. J.; Krzton-Maziopa, A.; Kalska-Szostko, B.

    2017-02-01

    One of the most popular nuclear probes, 57Fe is used for the investigation of orientations of hyperfine fields and also for the determination of other important properties. In particular, the orientation of iron magnetic moments can be unambiguously determined, including its signs. Experiments with polarized radiation are presented with regard to selected systems. Orientation of electric field gradient is used for acquiring information about the shape of the texture-free spectra. Applications on the analysis of iron-based superconductors are presented.

  16. Study of nuclear matter density distributions using hadronic probes

    SciTech Connect

    Kohama, Akihisa; Iida, Kei; Oyamatsu, Kazuhiro

    2011-05-06

    We briefly review our formula for a proton-nucleus total reaction cross section, {sigma}{sub R}, constructed in the black-sphere approximation of nuclei, in which a nucleus is viewed as a 'black' sphere of radius 'a'. Some years ago, using the Glauber model, one of the authors (A.K.) and his collaborators performed numerical simulations to examine the possibility to probe the nuclear matter density distributions of neutron-rich unstable nuclei from proton elastic scatterings 'model-independently'. The present study is another attempt to seek a 'model-independent' framework for systematically analyzing scattering data for studying the matter density distributions of atomic nuclei.

  17. Determination of hyperfine fields orientation in nuclear probe techniques.

    PubMed

    Szymański, K; Olszewski, W; Satuła, D; Gawryluk, D J; Krzton-Maziopa, A; Kalska-Szostko, B

    2017-02-15

    One of the most popular nuclear probes, (57)Fe is used for the investigation of orientations of hyperfine fields and also for the determination of other important properties. In particular, the orientation of iron magnetic moments can be unambiguously determined, including its signs. Experiments with polarized radiation are presented with regard to selected systems. Orientation of electric field gradient is used for acquiring information about the shape of the texture-free spectra. Applications on the analysis of iron-based superconductors are presented.

  18. Precision Nuclear Beta Spectroscopy as a Probe for BSM Physics

    NASA Astrophysics Data System (ADS)

    Sprow, Aaron

    2017-01-01

    The shape of nuclear beta decay spectra is sensitive to new physics such as scalar and tensor currents, and weak magnetism. By selecting an appropriate nuclear species, it is possible to disentangle these effects. 45Ca, which undergoes a predominantly Gamow-Teller transition with an end-point energy of 256 keV, is an excellent probe for tensor couplings. Recently, the 45Ca beta decay spectrum was measured in the Caltech/UCNA 4 π magnetic spectrometer instrumented with large, highly-pixelated Si detectors at the Los Alamos National Laboratory UCN facility. This detection system, in conjunction with an extremely thin foil source preparation, allows for a full reconstruction of events to build a precise spectrum. Preliminary results of the analysis of this data will be presented.

  19. Nuclear structure studies with medium energy probes. [Northwestern Univ

    SciTech Connect

    Seth, Kamal K.

    1980-01-01

    Progress in the continuing program of experimental research in nuclear structure with medium-energy probes during the year 1979-1980 is reviewed, and the research activities planned for the year 1980-1981 are discussed. In the study of pion-induced reactions emphasis is placed on investigation of isovector characteristics of nuclear excitations and on double charge exchange reactions. Pion production studies form the major part of the program of experiments with proton beams of 400 to 800 MeV at LAMPF. Current emphasis is on the bearing of these investigations on di-baryon existence. The study of high-spin states and magnetic scattering constitute the main goals of the electron scattering program at Bates. Representative results are presented; completed work is reported in the usual publications. (RWR)

  20. Nuclear micro-probe analysis of Arabidopsis thaliana leaves

    NASA Astrophysics Data System (ADS)

    Ager, F. J.; Ynsa, M. D.; Domínguez-Solís, J. R.; López-Martín, M. C.; Gotor, C.; Romero, L. C.

    2003-09-01

    Phytoremediation is a cost-effective plant-based approach for remediation of soils and waters which takes advantage of the remarkable ability of some plants to concentrate elements and compounds from the environment and to metabolize various molecules in their tissues, such as toxic heavy metals and organic pollutants. Nowadays, phytoremediation technology is becoming of paramount importance when environmental decontamination is concerned, due to the emerging knowledge of its physiological and molecular mechanisms and the new biological and engineering strategies designed to optimize and improve it. In addition, the feasibility of using plants for environmental cleanup has been confirmed by many different trials around the world. Arabidopsis thaliana plants can be used for basic studies to improve the technology on phytoremediation. Making use of nuclear microscopy techniques, in this paper we study leaves of wild type and transgenic A. thaliana plants grown in a cadmium-rich environment under different conditions. Micro-PIXE, RBS and SEM analyses, performed on the scanning proton micro-probe at the CNA in Seville (Spain), prove that cadmium is preferentially sequestered in the central region of epidermal trichome and allow comparing the effects of genetic modifications.

  1. Strange exotic atoms

    NASA Astrophysics Data System (ADS)

    Friedman, E.

    1998-08-01

    Exotic atoms of K- and Σ- are analyzed using density-dependent optical potentials constrained by a low-density limit. Emphasis is placed on radial sensitivities of the real potential. A potential depth of 180MeV inside nuclei is confirmed for K-. For Σ- a shallow attractive potential outside the nuclear surface becomes repulsive in the interior. The information content of limited data sets is demonstrated.

  2. Exotic power and propulsion concepts

    NASA Technical Reports Server (NTRS)

    Forward, Robert L.

    1990-01-01

    The status of some exotic physical phenomena and unconventional spacecraft concepts that might produce breakthroughs in power and propulsion in the 21st Century are reviewed. The subjects covered include: electric, nuclear fission, nuclear fusion, antimatter, high energy density materials, metallic hydrogen, laser thermal, solar thermal, solar sail, magnetic sail, and tether propulsion.

  3. Anatomizing Exotic Production of the Higgs Boson

    SciTech Connect

    Yu, Felix

    2014-07-10

    We discuss exotic production modes of the Higgs boson and how their phenomenology can be probed in current Higgs analyses. We highlight the importance of differential distributions in disentangling standard production mechanisms from exotic modes. We present two model benchmarks for exotic Higgs production arising from chargino-neutralino production and study their impact on the current Higgs dataset. As a corollary, we emphasize that current Higgs coupling fits do not fully explore the space of new physics deviations possible in Higgs data.

  4. Detection of tricuspid insufficiency by portable nuclear probe monitoring over the liver

    SciTech Connect

    Dey, H.M.; Schulman, P.; Smith, V.E.; Karimeddini, M.K.; Spencer, R.P.

    1983-12-01

    A case is presented in which a portable nuclear scintillation probe was used to detect tricuspid regurgitation. An electrocardiographically-gated scintigraphic collection obtained over the liver was correlated with findings from contrast echocardiography and jugular venous pulse tracings. The nuclear probe may provide a simple means for the detection of tricuspid insufficiency. It remains to be determined if quantification of severity will be possible.

  5. Sealed magic angle spinning nuclear magnetic resonance probe and process for spectroscopy of hazardous samples

    SciTech Connect

    Cho, Herman M.; Washton, Nancy M.; Mueller, Karl T.; Sears, Jr., Jesse A.; Townsend, Mark R.; Ewing, James R.

    2016-06-14

    A magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) probe is described that includes double containment enclosures configured to seal and contain hazardous samples for analysis. The probe is of a modular design that ensures containment of hazardous samples during sample analysis while preserving spin speeds for superior NMR performance and convenience of operation.

  6. Precision lifetime measurements in light exotic nuclei

    NASA Astrophysics Data System (ADS)

    McCutchan, Elizabeth

    2017-01-01

    A new generation of ab-initio calculations, based on realistic two- and three-body forces have had a profound impact on our understanding of nuclei. They have shed light on topics such as the origin of effective forces (like spin-orbit and tensor interactions) and the mechanisms behind cluster and pairing correlations. New precise data are required to both better parameterize the three body forces and to improve numerical methods. A sensitive probe of the structure of light nuclei comes from their electromagnetic transition rates. A refined Doppler Shift Attenuation Method (DSAM) will be outlined which is used to precisely measure lifetimes in light nuclei and helps to reduce and quantity systematic uncertainties in the measurement. Using this careful DSAM, we have made a series of precise measurements of electromagnetic transition strengths in Li isotopes, A =10 nuclei, and the exotic halo nucleus, 12Be. Various phenomena, such as alpha clustering and meson-exchange currents, can be investigated in these seemingly simple systems, while the collection of data spanning stable to neutron-rich, allows us to probe the influence of additional valence neutrons. This talk will report on what has been learned, and the challenges that lie in the future, both in experiment and theory, as we push to describing and measuring even more exotic systems. Work supported by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy under contract No. DE-AC02-98CH10886.

  7. Nuclear research with the electromagnetic probe. Final progress report

    SciTech Connect

    Meziani, Z.E.

    1994-10-01

    This is the final report on the research carried at Stanford University under contract DE-FG03-88ER40439. All the work accomplished under this grant is reported in the publications listed as part of the Principal Investigator bibliography at the end of this report. In the last few years our research was directed at some of the forefront questions in nuclear physics. We investigated the nuclear medium effects on the intrinsic properties of bound nucleons, specifically the ectromagnetic form factors. For these studies we performed a number of specialized electron scattering experiments with specific sensitivity to nuclear medium effects. At the next level of structure, elementary constituents of matter are quarks and gluons. Defining the energy regime where the quark-gluon description of nuclear systems becomes more relevant than the nucleon-meson description is of great importance in thoroughly understanding the nuclear structure. To explore this transition region, we studied the scaling region in the disintegration of the deuteron, the simplest nuclear system with high energy photons. Finally we focused on the investigation of the nucleon internal spin structure along with the test of the Bjoerken sum rule a fundamental sum rule of QCD.

  8. Compact endocavity diagnostic probes for nuclear radiation detection

    DOEpatents

    Cui, Yonggang; James, Ralph; Bolotnikov, Aleksey

    2014-08-26

    This invention relates to the field of radiation imaging. In particular, the invention relates to an apparatus and a method for imaging tissue or an inanimate object using a novel probe that has an integrated solid-state semiconductor detector and complete readout electronics circuitry.

  9. Probing nuclear bubble structure via neutron star asteroseismology

    NASA Astrophysics Data System (ADS)

    Sotani, Hajime; Iida, Kei; Oyamatsu, Kazuhiro

    2017-01-01

    We consider torsional oscillations that are trapped in a layer of spherical-hole (bubble) nuclear structure, which is expected to occur in the deepest region of the inner crust of a neutron star. Because this layer intervenes between the phase of slab nuclei and the outer core of uniform nuclear matter, torsional oscillations in the bubble phase can be excited separately from usual crustal torsional oscillations. We find from eigenmode analyses for various models of the equation of state of uniform nuclear matter that the fundamental frequencies of such oscillations are almost independent of the incompressibility of symmetric nuclear matter, but strongly depend on the slope parameter of the nuclear symmetry energy L. Although the frequencies are also sensitive to the entrainment effect, i.e. what portion of nucleons outside bubbles contribute to the oscillations, by having such a portion fixed, we can successfully fit the calculated fundamental frequencies of torsional oscillations in the bubble phase inside a star of specific mass and radius as a function of L. By comparing the resultant fitting formula to the frequencies of quasi-periodic oscillations (QPOs) observed from the soft-gamma repeaters, we find that each of the observed low-frequency QPOs can be identified either as a torsional oscillation in the bubble phase or as a usual crustal oscillation, given generally accepted values of L for all the stellar models are considered here.

  10. Probing vibrational anisotropy with nuclear resonance vibrational spectroscopy.

    SciTech Connect

    Pavlik, J. W.; Barabanschikov, A.; Oliver, A. G.; Alp, E. E.; Sturhahn, W.; Zhao, J.; Sage, J. T.; Scheidt, W. R.

    2010-06-14

    A NRVS single-crystal study (NRVS=nuclear resonance vibrational spectroscopy) has provided detailed information on the in-plane modes of nitrosyl iron porphyrinate [Fe(oep)(NO)] (see picture; oep=octaethylporphyrin). The axial nitrosyl ligand controls the direction of the in-plane iron motion.

  11. Application of a portable nuclear magnetic resonance surface probe to porous media.

    PubMed

    Marko, Andriy; Wolter, Bernd; Arnold, Walter

    2007-03-01

    A portable nuclear magnetic resonance (NMR) surface probe was used to determine the time-dependent self-diffusion coefficient D(t) of water molecules in two fluid-filled porous media. The measuring equipment and the inhomogeneous magnetic fields in the sensitive volume of the probe are described. It is discussed how to evaluate D(t) using a surface probe from the primary and stimulated echoes generated in three-pulse experiments. Furthermore, the evaluation of D(t) allows one to determine the geometrical structure of porous materials.

  12. The K sup + as a probe of nuclear medium effects

    SciTech Connect

    Chrien, R.E.

    1992-01-01

    The study of the K+ total cross sections on a wide range of nuclei has revealed important modifications of the free-space K+ -nucleon interaction when the nucleon is embedded in a nucleus. In addition to the previously published data on carbon and deuterium we report here the extension of such measurements to lithium, silicon, and calcium. We demonstrate that the previous reported medium modifications for carbon occur quite generally. The results are discussed as evidence for partial quark deconfinement at nuclear densities.

  13. Probing nuclear pore complex architecture with proximity-dependent biotinylation.

    PubMed

    Kim, Dae In; Birendra, K C; Zhu, Wenhong; Motamedchaboki, Khatereh; Doye, Valérie; Roux, Kyle J

    2014-06-17

    Proximity-dependent biotin identification (BioID) is a method for identifying protein associations that occur in vivo. By fusing a promiscuous biotin ligase to a protein of interest expressed in living cells, BioID permits the labeling of proximate proteins during a defined labeling period. In this study we used BioID to study the human nuclear pore complex (NPC), one of the largest macromolecular assemblies in eukaryotes. Anchored within the nuclear envelope, NPCs mediate the nucleocytoplasmic trafficking of numerous cellular components. We applied BioID to constituents of the Nup107-160 complex and the Nup93 complex, two conserved NPC subcomplexes. A strikingly different set of NPC constituents was detected depending on the position of these BioID-fusion proteins within the NPC. By applying BioID to several constituents located throughout the extremely stable Nup107-160 subcomplex, we refined our understanding of this highly conserved subcomplex, in part by demonstrating a direct interaction of Nup43 with Nup85. Furthermore, by using the extremely stable Nup107-160 structure as a molecular ruler, we defined the practical labeling radius of BioID. These studies further our understanding of human NPC organization and demonstrate that BioID is a valuable tool for exploring the constituency and organization of large protein assemblies in living cells.

  14. Nuclear magnetic resonance probes of membrane biophysics: Structure and dynamics

    NASA Astrophysics Data System (ADS)

    Leftin, Avigdor

    The phospholipid membrane is a self-assembled, dynamic molecular system that may exist alone in association with only water, or in complex systems comprised of multiple lipid types and proteins. In this dissertation the intra- and inter-molecular forces responsible for the atomistic, molecular and collective equilibrium structure and dynamics are studied by nuclear magnetic resonance spectroscopy (NMR). The multinuclear NMR measurements and various experimental techniques are able to provide data that enable the characterization of the hierarchical spatio-temporal organization of the phospholipid membrane. The experimental and theoretical studies conducted target membrane interactions ranging from model systems composed of only water and lipids, to multiple component domain forming membranes that are in association with peripheral and trans-membrane proteins. These measurements consisit of frequency spectrum lineshapes and nuclear-spin relaxation rates obtained using 2H NMR, 13C NMR, 31P NMR and 1H NMR. The changes of these experimental observables are interpreted within a statistical thermodynamic framework that allows the membrane structure, activation energies, and correlation times of motion to be determined. The cases presented demonstrate how fundamental principles of NMR spectroscopy may be applied to a host of membranes, leading to the biophysical characterization of membrane structure and dynamics.

  15. Double-tuned single coil probe for nuclear magnetic resonance spectrometer

    SciTech Connect

    McKay, R.A.

    1984-05-01

    A double-tuned single coil probe for a nuclear magnetic resonance spectrometer having improved sensitivity is described comprising a double-tuned circuit means in which the low frequency irradiation is fed to a transmission line through an inductor means. The double-tuned circuit means of the invention may be remotely disposed from the magnetic field which results in greater sensitivity.

  16. Monopole strength as a probe of nuclear shape mixing

    SciTech Connect

    Meyer, R.A.

    1987-08-17

    The monopole strength, MS, within a single set of nuclear shape excitations is compared with the MS between different shapes. After misconceptions are pointed out concerning the spin dependence of B(E2) values, MS properties are juxtaposed with gamma-ray and beta-decay properties of /sup 70/Se, /sup 96/Zr, /sup 102/Pd, and the N = 60 isotones to illustrate the utility of combined investigations and evidence is given for the observation of a two-phonon octupole multiplet. Finally, consideration is given to the dominance of the /sup 3/S/sub 1/ force in producing deformation in the N > 50 1g nuclei. 23 refs., 4 figs.

  17. Isospin effects on neutrons as a probe of nuclear dissipation

    SciTech Connect

    Ye, W.

    2009-03-15

    Based on a dynamical Langevin equation coupled with a statistical decay model, we calculate the excess of the precision neutron multiplicity of the heavy nuclei {sup 240}Cf, {sup 246}Cf, {sup 252}Cf, and {sup 240}U over that predicted by the standard statistical model as a function of the postsaddle dissipation strength. We find that with increasing isospin of the system, the sensitivity of the excess to the dissipation strength decreases substantially. Moreover, for {sup 240}U, this excess is no longer sensitive to the nuclear dissipation. These results suggest that, on the experimental side, to accurately obtain information of the postsaddle dissipation strength by measuring the neutron multiplicity evaporated during the fission process of heavy nuclei, it is best to populate those compound systems with low isospin.

  18. Fragmentation in isotopic and isobaric systems as probe of density dependence of nuclear symmetry energy

    NASA Astrophysics Data System (ADS)

    Kaur, Mandeep; Gautam, Sakshi; Puri, Rajeev K.

    2016-11-01

    We probe the density-dependent behavior of symmetry energy using the yield of various fragments in central collisions of various isotopic and isobaric colliding pairs. We calculate the yields of free nucleons, light charged particles and intermediate mass fragments in neutron-rich colliding systems as well as the ratio of relative yields of above fragments and free nucleons. Our findings reveal that the ratio of relative yield of light charged particles poses better candidate to probe the density dependence of nuclear symmetry energy.

  19. Exotic shapes and exotic clusterization

    SciTech Connect

    Cseh, J.; Darai, J.; Algora, A.

    2011-10-28

    The interrelation of the largely elongated nuclear shapes and clusterization is discussed by applying semimicroscopic methods. {sup 36}Ar is considered as a specific example, where recent experimental heavy-ion scattering data seem to justify the theoretical predictions on the hyperdeformed states. Alpha-emitting reactions are also suggested for its population.

  20. Significant role of fissility in evaporation residue cross sections as a probe of presaddle nuclear dissipation

    SciTech Connect

    Ye, W.

    2010-01-15

    Using a Langevin model, we explore the role of fissility in probing presaddle nuclear dissipation by calculating the excess of the evaporation residue cross section over its standard statistical-model value as a function of nuclear dissipation strength for nuclei {sup 190}Os and {sup 210}Po, which are taken as two representatives that have the same neutron-to-proton ratio (N/Z) but have a difference in fissility. We find that a large fissility not only amplifies the dissipation effects on the excess of evaporation residues, but also significantly increases the sensitivity of this excess to nuclear dissipation. The results suggest that in experiments, to obtain a more accurate information of nuclear dissipation inside the saddle point by measuring evaporation residue cross sections, it is best to populate among the various compound systems with equal N/Z those with high fissility.

  1. Probing the N=32 Shell Closure below the Magic Proton Number Z=20: Mass Measurements of the Exotic Isotopes ^{52,53}K.

    PubMed

    Rosenbusch, M; Ascher, P; Atanasov, D; Barbieri, C; Beck, D; Blaum, K; Borgmann, Ch; Breitenfeldt, M; Cakirli, R B; Cipollone, A; George, S; Herfurth, F; Kowalska, M; Kreim, S; Lunney, D; Manea, V; Navrátil, P; Neidherr, D; Schweikhard, L; Somà, V; Stanja, J; Wienholtz, F; Wolf, R N; Zuber, K

    2015-05-22

    The recently confirmed neutron-shell closure at N=32 has been investigated for the first time below the magic proton number Z=20 with mass measurements of the exotic isotopes (52,53)K, the latter being the shortest-lived nuclide investigated at the online mass spectrometer ISOLTRAP. The resulting two-neutron separation energies reveal a 3 MeV shell gap at N=32, slightly lower than for 52Ca, highlighting the doubly magic nature of this nuclide. Skyrme-Hartree-Fock-Bogoliubov and ab initio Gorkov-Green function calculations are challenged by the new measurements but reproduce qualitatively the observed shell effect.

  2. Simulation of electromagnetic and strange probes of dense nuclear matter at NICA/MPD

    NASA Astrophysics Data System (ADS)

    Zinchenko, A.; Kolesnikov, V.; Vasendina, V.

    2016-01-01

    The main task of the NICA/MPD physics program is a study of the properties of nuclear matter under extreme conditions achieved in collisions of heavy ions. These properties can reveal themselves through different probes, the most promising among those being the lepton-antilepton pairs and strange hadrons. In this paper the MPD performance for measuring the electron-positron pairs and strange hyperons in central Au+Au collisions at NICA energies is presented.

  3. Exotic dancing and health.

    PubMed

    Maticka-Tyndale, E; Lewis, J; Clark, J P; Zubick, J; Young, S

    2000-01-01

    The health and safety of women who work as exotic dancers are firmly embedded within the social organization of the strip club and the broader social, economic and political context of the work of exotic dancing. Exotic dancers in this study expressed health concerns associated with: the effects of costuming and appearance requirements; dirty work environments; problems due to stigmatization, sexual harassment and assault; and police disinterest or victim blaming. The balance between benefits and hazards related to exotic dancing is influenced not only by the personal choices made by dancers, but also by the organization of the strip club and the broader context within which exotic dancing takes place.

  4. Effect of nuclear motion on molecular high order harmonic pump probe spectroscopy.

    PubMed

    Bredtmann, Timm; Chelkowski, Szczepan; Bandrauk, André D

    2012-11-26

    We study pump-probe schemes for the real time observation of electronic motion on attosecond time scale in the molecular ion H(2)(+) and its heavier isotope T(2)(+) while these molecules dissociate on femtosecond time scale by solving numerically the non-Born-Oppenheimer time-dependent Schrödinger equation. The UV pump laser pulse prepares a coherent superposition of the three lowest lying quantum states and the time-delayed mid-infrared, intense few-femtosecond probe pulse subsequently generates molecular high-order harmonics (MHOHG) from this coherent electron-nuclear wavepacket (CENWP). Varying the pump-probe time delay by a few hundreds of attoseconds, the MHOHG signal intensity is shown to vary by orders of magnitude. Due to nuclear movement, the coherence of these two upper states and the ground state is lost after a few femtoseconds and the MHOHG intensity variations as function of pump-probe delay time are shown to be equal to the period of electron oscillation in the coherent superposition of the two upper dissociative quantum states. Although this electron oscillation period and hence the periodicity of the harmonic spectra are quite constant over a wide range of internuclear distances, a strong signature of nuclear motion is seen in the actual shapes and ways in which these spectra change as a function of pump-probe delay time, which is illustrated by comparison of the MHOHG spectra generated by the two isotopes H(2)(+) and T(2)(+). Two different regimes corresponding roughly to internuclear distances R < 4a(0) and R > 4a(0) are identified: For R < 4a(0), the intensity of a whole range of frequencies in the plateau region is decreased by orders of magnitude when the delay time is changed by a few hundred attoseconds whereas in the cutoff region the peaks in the MHOHG spectra are red-shifted with increasing pump-probe time delay. For R > 4a(0), on the other hand, the peaks both in the cutoff and plateau region are red-shifted with increasing delay times

  5. A broadband single-chip transceiver for multi-nuclear NMR probes

    SciTech Connect

    Grisi, Marco Gualco, Gabriele; Boero, Giovanni

    2015-04-15

    In this article, we present an integrated broadband complementary metal-oxide semiconductor single-chip transceiver suitable for the realization of multi-nuclear pulsed nuclear magnetic resonance (NMR) probes. The realized single-chip transceiver can be interfaced with on-chip integrated microcoils or external LC resonators operating in the range from 1 MHz to 1 GHz. The dimension of the chip is about 1 mm{sup 2}. It consists of a radio-frequency (RF) power amplifier, a low-noise RF preamplifier, a frequency mixer, an audio-frequency amplifier, and fully integrated transmit-receive switches. As specific example, we show its use for multi-nuclear NMR spectroscopy. With an integrated coil of about 150 μm external diameter, a {sup 1}H spin sensitivity of about 1.5 × 10{sup 13} spins/Hz{sup 1/2} is achieved at 7 T.

  6. A broadband single-chip transceiver for multi-nuclear NMR probes

    NASA Astrophysics Data System (ADS)

    Grisi, Marco; Gualco, Gabriele; Boero, Giovanni

    2015-04-01

    In this article, we present an integrated broadband complementary metal-oxide semiconductor single-chip transceiver suitable for the realization of multi-nuclear pulsed nuclear magnetic resonance (NMR) probes. The realized single-chip transceiver can be interfaced with on-chip integrated microcoils or external LC resonators operating in the range from 1 MHz to 1 GHz. The dimension of the chip is about 1 mm2. It consists of a radio-frequency (RF) power amplifier, a low-noise RF preamplifier, a frequency mixer, an audio-frequency amplifier, and fully integrated transmit-receive switches. As specific example, we show its use for multi-nuclear NMR spectroscopy. With an integrated coil of about 150 μm external diameter, a 1H spin sensitivity of about 1.5 × 1013 spins/Hz1/2 is achieved at 7 T.

  7. Nuclear resonance scattering of synchrotron radiation as a unique electronic, structural and thermodynamic probe

    SciTech Connect

    Alp, E. Ercan; Sturhahn, Wolfgang; Toellner, Thomas S.; Zhao, Jiyong; Leu, Bogdan M.

    2012-05-09

    Discovery of Moessbauer effect in a nuclear transition was a remarkable development. It revealed how long-lived nuclear states with relatively low energies in the kiloelectron volt (keV) region can be excited without recoil. This new effect had a unique feature involving a coupling between nuclear physics and solid-state physics, both in terms of physics and sociology. Physics coupling originates from the fact that recoilless emission and absorption or resonance is only possible if the requirement that nuclei have to be bound in a lattice with quantized vibrational states is fulfilled, and that the finite electron density on the nucleus couples to nuclear degrees of freedom leading to hyperfine interactions. thus, Moessbauer spectroscopy allows peering into solid-state effects using unique nuclear transitions. Sociological aspects of this coupling had been equally startling and fruitful. The interaction between diverse scientific communities, who learned to use Moessbauer spectroscopy proved to be very valuable. For example, biologists, geologists, chemists, physics, materials scientists, and archeologists, all sharing a common spectroscopic technique, also learned to appreciate the beauty and intricacies of each other's fields. As a laboratory-based technique, Moessbauer spectroscopy matured by the end of the 1970s. Further exciting developments took place when accelerator-based techniques were employed, like synchrotron radiation or 'in-beam'Moessbauer experiments with implanted radioactive ions. More recently, two Moessbauer spectrometers on the surface of the Mars kept the technique vibrant and viable up until present time. In this chapter, the authors look into some of the unique aspects of nuclear resonance excited with synchrotron radiation as a probe of condensed matter, including magnetism, valence, vibrations, and lattice dynamics, and review the development of nuclear resonance inelastic x-ray scattering (NRIXS) and synchrotron Moessbauer spectroscopy

  8. Electromagnetic radiation as a probe of the initial state and of viscous dynamics in relativistic nuclear collisions

    NASA Astrophysics Data System (ADS)

    Vujanovic, Gojko; Paquet, Jean-François; Denicol, Gabriel S.; Luzum, Matthew; Jeon, Sangyong; Gale, Charles

    2016-07-01

    The penetrating nature of electromagnetic signals makes them suitable probes to explore the properties of the strongly interacting medium created in relativistic nuclear collisions. We examine the effects of the initial conditions and shear relaxation time on the spectra and flow coefficients of electromagnetic probes, using an event-by-event 3+1-dimensional viscous hydrodynamic simulation (music).

  9. A highly sensitive ratiometric fluorescent probe for the detection of cytoplasmic and nuclear hydrogen peroxide.

    PubMed

    Wen, Ying; Liu, Keyin; Yang, Huiran; Li, Yi; Lan, Haichuang; Liu, Yi; Zhang, Xinyu; Yi, Tao

    2014-10-07

    As a marker for oxidative stress and a second messenger in signal transduction, hydrogen peroxide (H2O2) plays an important role in living systems. It is thus critical to monitor the changes in H2O2 in cells and tissues. Here, we developed a highly sensitive and versatile ratiometric H2O2 fluorescent probe (NP1) based on 1,8-naphthalimide and boric acid ester. In response to H2O2, the ratio of its fluorescent intensities at 555 and 403 nm changed 1020-fold within 200 min. The detecting limit of NP1 toward H2O2 is estimated as 0.17 μM. It was capable of imaging endogenous H2O2 generated in live RAW 264.7 macrophages as a cellular inflammation response, and especially, it was able to detect H2O2 produced as a signaling molecule in A431 human epidermoid carcinoma cells through stimulation by epidermal growth factor. This probe contains an azide group and thus has the potential to be linked to various molecules via the click reaction. After binding to a Nuclear Localization Signal peptide, the peptide-based combination probe (pep-NP1) was successfully targeted to nuclei and was capable of ratiometrically detecting nuclear H2O2 in living cells. These results indicated that NP1 was a highly sensitive ratiometric H2O2 dye with promising biological applications.

  10. Probing nuclear effects using single-transverse kinematic imbalance with MINERvA

    SciTech Connect

    Lu, X. -G.; Betancourt, M.

    2016-08-15

    Kinematic imbalance of the final-state particles in the plane transverse to the neutrino direction provides a sensitive probe of nuclear effects. In this contribution, we report the MINERvA measurement of the single-transverse kinematic imbalance in neutrino charged-current quasielastic-like events on CH targets. To improve the momentum measurements of the final-state particles, we develop a method to select elastically scattering contained (ESC) protons and a general procedure to correct the transverse momentum scales.

  11. Coaxial probe for nuclear magnetic resonance diffusion and relaxation correlation experiments

    SciTech Connect

    Tang, Yiqiao; Hürlimann, Martin; Mandal, Soumyajit; Paulsen, Jeffrey; Song, Yi-Qiao

    2014-02-21

    A coaxial nuclear magnetic resonance (NMR) probe is built to measure diffusion and relaxation properties of liquid samples. In particular, we demonstrate the acquisition of two-dimensional (2D) distribution functions (T{sub 1}-T{sub 2} and diffusion–T{sub 2}), essential for fluids characterization. The compact design holds promise for miniaturization, thus enabling the measurement of molecular diffusion that is inaccessible to conventional micro-NMR setups. Potential applications range from crude oil characterization to biomolecular screening and detections.

  12. Probing an NV Center's Nuclear Spin Environment with Coherent Population Trapping

    NASA Astrophysics Data System (ADS)

    Levonian, David; Goldman, Michael; Singh, Swati; Markham, Matthew; Twitchen, Daniel; Lukin, Mikhail

    2016-05-01

    Nitrogen-vacancy (NV) centers in diamond have emerged as a versatile atom-like system, finding diverse applications in metrology and quantum information science, but interaction between the NV center's electronic spin and its nuclear spin environment represent a major source of decoherence. We use optical techniques to monitor and control the nuclear bath surrounding an NV center. Specifically, we create an optical Λ-system using the | +/- 1 > components of the NV center's spin-triplet ground state. When the Zeeman splitting between the two states is equal to the two-photon detuning between the lasers, population is trapped in the resulting dark state. Measuring the rate at which the NV center escapes from the dark state therefore gives information on how spin bath dynamics change the effective magnetic field experienced by the NV center. By monitoring statistics of the emitted photons, we plan to probe non-equilibrium dynamics of the bath.

  13. Defect-induced magnetism in SiC probed by nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Zhang, Z. T.; Dmytriieva, D.; Molatta, S.; Wosnitza, J.; Wang, Yutian; Helm, M.; Zhou, Shengqiang; Kühne, H.

    2017-02-01

    We give evidence for intrinsic defect-induced bulk paramagnetism in SiC by means of 13C and 29Si nuclear magnetic resonance (NMR) spectroscopy. The temperature dependence of the internal dipole-field distribution, probed by the spin part of the NMR Knight shift and the spectral linewidth, follows the Curie law and scales very well with the macroscopic dc susceptibility. In order to quantitatively analyze the NMR spectra, a microscopic model based on dipole-dipole interactions was developed. The very good agreement between these simulations and the NMR data establishes a direct relation between the frequency distribution of the spectral intensity and the corresponding real-space volumes of nuclear spins. The presented approach by NMR can be applied to a variety of similar materials and, thus, opens a new avenue for the microscopic exploration and exploitation of diluted bulk magnetism in semiconductors.

  14. Development of Nuclear Magnetic Resonance Pulse Sequences and Probes to Study Biomacromolecules

    SciTech Connect

    Cosman, M; Krishnan, V V; Maxwell, R

    2001-02-26

    The determination of the three dimensional structures at high resolution of biomolecules, such as proteins and nucleic acids, enables us to understand their function at the molecular level. At the present time, there are only two methods available for determining such structures, nuclear magnetic resonance (NMR) spectroscopy and X-ray diffraction. Compared to well-established X-ray diffraction techniques, NMR methodology is relatively new and has many areas in which improvement can still be attained. In this project, we focused on the development of new NMR probes and pulse sequences that were tailored to tackle specific problems that are not adequately addressed by current technology. Probes are the hardware that contain the radio frequency (RF) circuitry used to both excite and detect the NMR signals. Pulse sequences are composed of a series of RF pulses and delays, which are applied to the sample held within the magnetic field by the probe, so as to manipulate the nuclear spins. Typically, a probe is developed for a specific set of nuclei and types of experiments and the pulse sequences are then written to use the probe in an optimal manner. In addition, the inter-development of instrumentation and methods are determined by the specific biological question to be examined. Thus our efforts focused on addressing an area of importance in NMR Structural Biology namely more effective ways to use the phosphorus ({sup 31}P) nucleus. Phosphorus is a very important biological element that is strategically located in nucleic acids, where it imparts negative charge and flexibility to RNA and DNA. It is also a component of the cellular membrane and thus interacts with membrane proteins. It is used in mechanisms to signal, activate or deactivate enzymes; and participates in energy storage and release. However, the phosphorus nucleus exhibits certain properties, such as poor spectral dispersion, low sensitivity of detection, and fast relaxation, which limit its effective use

  15. Cryogenic sample exchange NMR probe for magic angle spinning dynamic nuclear polarization

    PubMed Central

    Barnes, Alexander B.; Mak-Jurkauskas, Melody L.; Matsuki, Yoh; Bajaj, Vikram S.; van der Wel, Patrick C. A.; DeRocher, Ronald; Bryant, Jeffrey; Sirigiri, Jagadishwar R.; Temkin, Richard J.; Lugtenburg, Johan; Herzfeld, Judith; Griffin, Robert G.

    2009-01-01

    We describe a cryogenic sample exchange system that dramatically improves the efficiency of magic angle spinning (MAS) dynamic nuclear polarization (DNP) experiments by reducing the time required to change samples and by improving long-term instrument stability. Changing samples in conventional cryogenic MAS DNP/NMR experiments involves warming the probe to room temperature, detaching all cryogenic, RF, and microwave connections, removing the probe from the magnet, replacing the sample, and reversing all the previous steps, with the entire cycle requiring a few hours. The sample exchange system described here — which relies on an eject pipe attached to the front of the MAS stator and a vacuum jacketed dewar with a bellowed hole — circumvents these procedures. To demonstrate the excellent sensitivity, resolution, and stability achieved with this quadruple resonance sample exchange probe, we have performed high precision distance measurements on the active site of the membrane protein bacteriorhodopsin. We also include a spectrum of the tripeptide N-f-MLF-OH at 100 K which shows 30 Hz linewidths. PMID:19356957

  16. Cryogenic sample exchange NMR probe for magic angle spinning dynamic nuclear polarization.

    PubMed

    Barnes, Alexander B; Mak-Jurkauskas, Melody L; Matsuki, Yoh; Bajaj, Vikram S; van der Wel, Patrick C A; Derocher, Ronald; Bryant, Jeffrey; Sirigiri, Jagadishwar R; Temkin, Richard J; Lugtenburg, Johan; Herzfeld, Judith; Griffin, Robert G

    2009-06-01

    We describe a cryogenic sample exchange system that dramatically improves the efficiency of magic angle spinning (MAS) dynamic nuclear polarization (DNP) experiments by reducing the time required to change samples and by improving long-term instrument stability. Changing samples in conventional cryogenic MAS DNP/NMR experiments involves warming the probe to room temperature, detaching all cryogenic, RF, and microwave connections, removing the probe from the magnet, replacing the sample, and reversing all the previous steps, with the entire cycle requiring a few hours. The sample exchange system described here-which relies on an eject pipe attached to the front of the MAS stator and a vacuum jacketed dewar with a bellowed hole-circumvents these procedures. To demonstrate the excellent sensitivity, resolution, and stability achieved with this quadruple resonance sample exchange probe, we have performed high precision distance measurements on the active site of the membrane protein bacteriorhodopsin. We also include a spectrum of the tripeptide N-f-MLF-OH at 100K which shows 30 Hz linewidths.

  17. Exotic Mammal Laparoscopy.

    PubMed

    Sladakovic, Izidora; Divers, Stephen J

    2016-01-01

    Laparoscopy is an evolving field in veterinary medicine, and there is an increased interest in using laparoscopic techniques in nondomestic mammals, including zoo animals, wildlife, and exotic pets. The aim of this article is to summarize the approach to laparoscopic procedures, including instrumentation, patient selection and preparation, and surgical approaches, and to review the current literature on laparoscopy in exotic mammals.

  18. Significant role of deformation in probing postsaddle nuclear dissipation with light particle emission

    SciTech Connect

    Ye, W.

    2010-05-15

    Using a one-dimensional Langevin model, we study the effects of deformation on the multiplicities of postsaddle neutrons, protons, alpha particles, and giant dipole resonance (GDR) gamma rays of a heavy fissioning system {sup 240}Cf as probes of postsaddle nuclear dissipation (beta). It is shown that postsaddle dissipation effects on these light particles have a significant deformation dependence. Furthermore, we find that the role of deformation depends on the type of the particle. It reduces the sensitive influence of beta on protons, alpha particles, and GDR gamma rays substantially, whereas it enhances the sensitivity of neutrons to beta. The results suggest that to accurately extract the postsaddle friction strength by comparing measured prescission particle multiplicities of heavy nuclei with calculations based on statistical models or stochastic equations like Langevin equations, it is important to take into account the deformation effects. The influence of model dimensionality is discussed.

  19. Burst Oscillation Probes of Neutron Stars and Nuclear Burning with LOFT

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod

    2012-01-01

    X-ray brightness oscillations during thermonuclear X-ray bursts--burst oscillations--have provided a new probe of neutron star spins as well as of the dependent nuclear burning processes. The frequency drift and amplitude evolution of the oscillations observed during bursts can in principle place constraints on the physics of thermonuclear flame spreading and the dynamics of the burning atmosphere. I use simulations appropriate to LOFT to explore the precision with which the time dependence of the oscillation frequency can be inferred. This can test, for example, different models for the frequency drift, such as up-lift versus geostrophic drift. I also explore the precision with which asymptotic frequencies can be constrained in order to estimate the capability for LOFT to detect the Doppler shifts induced by orbital motion of the neutron star from a sample of bursts at different orbital phases.

  20. Reacting to nuclear power systems in space: American public protests over outer planetary probes since the 1980s

    NASA Astrophysics Data System (ADS)

    Launius, Roger D.

    2014-03-01

    The United States has pioneered the use of nuclear power systems for outer planetary space probes since the 1970s. These systems have enabled the Viking landings to reach the surface of Mars and both Pioneers 10 and 11 and Voyagers 1 and 2 to travel to the limits of the solar system. Although the American public has long been concerned about safety of these systems, in the 1980s a reaction to nuclear accidents - especially the Soviet Cosmos 954 spacecraft destruction and the Three Mile Island nuclear power plant accidents - heightened awareness about the hazards of nuclear power and every spacecraft launch since that time has been contested by opponents of nuclear energy. This has led to a debate over the appropriateness of the use of nuclear power systems for spacecraft. It has also refocused attention on the need for strict systems of control and rigorous checks and balances to assure safety. This essay describes the history of space radioisotope power systems, the struggles to ensure safe operations, and the political confrontation over whether or not to allow the launch the Galileo and Cassini space probes to the outer planets. Effectively, these efforts have led to the successful flights of 12 deep space planetary probes, two-thirds of them operated since the accidents of Cosmos 954, Three Mile Island, and Chernobyl.

  1. Exotic statistics of leapfrogging vortex rings.

    PubMed

    Niemi, Antti J

    2005-04-01

    The leapfrogging motion of vortex rings is a three-dimensional version of the motion that in two dimensions leads to exotic exchange statistics. The statistical phase factor can be computed using the hydrodynamical Euler equation, which suggests that three-dimensional exotic exchange statistics is a common property of vortex rings in a variety of quantum liquids and gases. Potential applications range from helium superfluids to Bose-Einstein condensed alkali gases, metallic hydrogen in its liquid phases, and maybe even nuclear matter in extreme conditions.

  2. Reaction theory for exotic nuclei

    SciTech Connect

    Bonaccorso, Angela

    2014-05-09

    Exotic nuclei are usually defined as those with unusual N/Z ratios. They can be found in the crust of neutron stars enbedded in a sea of electrons or created in laboratory by fragmentation of a primary beam (in-flight method) or of the target (ISOL method). They are extremely important for nuclear astrophysics, see for example Ref.[1]. Furthermore by studying them we can check the limits of validity of nuclear reaction and structure models. This contribution will be devoted to the understanding of how by using reaction theory and comparing to the data we can extract structure information. We shall discuss the differences between the mechanisms of transfer and breakup reactions, an we will try to explain how nowadays it is possible to do accurate spectroscopy in extreme conditions.

  3. D(s) meson as a quantitative probe of diffusion and hadronization in nuclear collisions.

    PubMed

    He, Min; Fries, Rainer J; Rapp, Ralf

    2013-03-15

    The modifications of D(s)-meson spectra in ultrarelativistic heavy-ion collisions are identified as a quantitative probe of key properties of the hot nuclear medium. The unique valence-quark content of the D(s)=cs̄ couples the well-known strangeness enhancement with the collective-flow pattern of primordially produced charm quarks. This idea is illustrated utilizing a consistent strong-coupling treatment with hydrodynamic bulk evolution and nonperturbative T-matrix interactions for both heavy-quark diffusion and hadronization in the quark-gluon plasma (QGP). A large enhancement of the D(s) nuclear modification factor at Relativistic Heavy Ion Collider is predicted, with a maximum of ∼1.5-1.8 at transverse momenta around 2  GeV/c. This is a direct consequence of the strong coupling of the heavy quarks to the QGP and their hadronization via coalescence with strange quarks. We furthermore introduce the effects of diffusion in the hadronic phase and suggest that an increase of the D-meson elliptic flow compared to the D(s) can disentangle the transport properties of hadronic and QGP liquids.

  4. Energetic M1 transitions as a probe of nuclear collectivity at high temperatures

    SciTech Connect

    Baktash, C.

    1987-01-01

    At ORNL, we have recently utilized the Spin Spectrometer setup to investigate the differential effects of increasing spin and excitation energy on nuclear shape and collectivity in /sup 158/Yb. Along the yrast line of this and other N = 88 nuclei, weakly prolate shapes gradually give way to triaxial, and then finally to non-collective oblate shapes as the spin approaches 40 h-bar. However, above the yrast line, large deformation and collectivity once again sets in. This is evidenced by the emergence of a broad quadrupole structure (E/sub ..gamma../ approx. = 1.2 MeV) in the continuum gamma-ray spectra that grows with increasing temperature. The short (sub ps) lifetimes of these transitions attest to the collective nature of these structures. The emergence and growth of the quadrupole structure at high excitation energies is closely correlated with the appearance of energetic (E/sub ..gamma../ approx. = 2.5 MeV), fast M1 transitions which form another broad structure in the continuum spectra. From the centroid of the M1 bump, a quadrupole deformation parameter of 0.35 is inferred. Because of this sensitivity, these energetic M1 transitions provide a unique probe of nuclear shape in the excitation energy range of approx. = 3 to 10 MeV. 6 refs., 2 figs.

  5. Probing quantum confinement at the atomic scale with optically detected nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Kempf, James G.

    2001-09-01

    Near-band-gap circularly polarized excitation in III-V semiconductors provides spin-polarized electrons that transfer spin order to lattice nuclei via fluctuations in the contact hyperfine interaction. This process of optical nuclear polarization and the complementary technique of optical detection of nuclear magnetic resonance (NMR) provide extreme sensitivity enhancement and spatial selectivity in structured samples, enabling collection of NMR spectra from samples such as single quantum wells or dots containing as few as ˜105 nuclei. Combining these advances with novel techniques for high spectral resolution, we have probed quantum-confined electronic states near the interface of a single epitaxially grown Al1-x As/GaAs (x = 0.36) heterojunction. Using a novel strategy that we refer to as POWER (p&barbelow;erturbations o&barbelow;bserved w&barbelow;ith e&barbelow;nhanced ṟesolution) NMR, multiple-pulse time suspension is synchronized with bandgap optical irradiation to reveal spectra of effective spin Hamiltonians that are differences between those of the occupied and unoccupied photoexcited electronic state. The underlying NMR linewidth is reduced by three orders of magnitude in these experiments, enabling resolution of an asymmetric line shape due to light-induced hyperfine interactions. The results are successfully fit with the coherent nuclear spin evolution and relaxation theoretically expected for sites distributed over the volume of an electronic excitation weakly localized at a point defect. This analysis establishes a one-to-one relationship, which can be used to follow nuclear spin diffusion, between optical Knight shift and the radial position of lattice nuclei. We have also introduced POWER NMR techniques to characterize the change in electric field associated with cycling from light-on to light-off states via a linear quadrupole Stark effect (LQSE) of the nuclear spins. Simulations of these NMR spectra in terms of the radial electric fields of

  6. TOPICAL REVIEW: Probing the nuclear symmetry energy with heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Di Toro, M.; Baran, V.; Colonna, M.; Greco, V.

    2010-08-01

    Heavy ion collisions (HICs) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. In this review we present a selection of new reaction observables in dissipative collisions particularly sensitive to the symmetry term of the nuclear equation of state (Iso-EoS). We will first discuss the isospin equilibration dynamics. At low energies this manifests via the recently observed dynamical dipole radiation, due to a collective neutron-proton oscillation with the symmetry term acting as a restoring force. At higher beam energies Iso-EoS effects will be seen in an isospin diffusion mechanism, via imbalance ratio measurements, in particular from correlations to the total kinetic energy loss. For fragmentation reactions in central events we suggest to look at the coupling between isospin distillation and radial flow. In neck fragmentation reactions important Iso-EoS information can be obtained from the fragment isospin content, velocity and alignment correlations. The high-density symmetry term can be probed from isospin effects on heavy-ion reactions at relativistic energies (few A GeV range), in particular for high transverse momentum selections of the reaction products. Rather isospin sensitive observables are proposed from nucleon/cluster emissions, collective flows and meson production. The possibility of shedding light on the controversial neutron/proton effective mass splitting in asymmetric matter is also suggested. A large symmetry repulsion at high baryon density will also lead to an 'earlier' hadron-deconfinement transition in n-rich matter. The binodal transition line of the (T, ρB) diagram is lowered to a region accessible through heavy-ion collisions in the energy range of the new planned facilities, e.g. the FAIR/NICA projects. Some observable effects of the formation of a mixed phase are suggested, in particular a neutron trapping mechanism. The dependence of the results on a suitable treatment of the isovector

  7. Synthesis and physicochemical characterization of novel phenotypic probes targeting the nuclear factor-kappa B signaling pathway

    PubMed Central

    Hershberger, Paul M; Peddibhotla, Satyamaheshwar; Sessions, E Hampton; Divlianska, Daniela B; Correa, Ricardo G; Pinkerton, Anthony B; Reed, John C

    2013-01-01

    Summary Activation of nuclear factor-kappa B (NF-κB) and related upstream signal transduction pathways have long been associated with the pathogenesis of a variety of inflammatory diseases and has recently been implicated in the onset of cancer. This report provides a synthetic and compound-based property summary of five pathway-related small-molecule chemical probes identified and optimized within the National Institutes of Health-Molecular Libraries Probe Center Network (NIH-MLPCN) initiative. The chemical probes discussed herein represent first-in-class, non-kinase-based modulators of the NF-κB signaling pathway, which were identified and optimized through either cellular phenotypic or specific protein-target-based screening strategies. Accordingly, the resulting new chemical probes may allow for better fundamental understanding of this highly complex biochemical signaling network and could advance future therapeutic translation toward the clinical setting. PMID:23766805

  8. Using a nano-flare probe to detect RNA in live donor cells prior to somatic cell nuclear transfer.

    PubMed

    Fu, Bo; Ren, Liang; Liu, Di; Ma, Jian-Zhang; An, Tie-Zhu; Yang, Xiu-Qin; Ma, Hong; Guo, Zhen-Hua; Zhu, Meng; Bai, Jing

    2016-01-01

    Many transgenes are silenced in mammalian cells (donor cells used for somatic cell nuclear transfer [SCNT]). Silencing correlated with a repressed chromatin structure or suppressed promoter, and it impeded the production of transgenic animals. Gene transcription studies in live cells are challenging because of the drawbacks of reverse-transcription polymerase chain reaction and fluorescence in situ hybridization. Nano-flare probes provide an effective approach to detect RNA in living cells. We used 18S RNA, a housekeeping gene, as a reference gene. This study aimed to establish a platform to detect RNA in single living donor cells using a Nano-flare probe prior to SCNT and to verify the safety and validity of the Nano-flare probe in order to provide a technical foundation for rescuing silenced transgenes in transgenic cloned embryos. We investigated cytotoxic effect of the 18S RNA-Nano-flare probe on porcine fetal fibroblasts, characterized the distribution of the 18S RNA-Nano-flare probe in living cells and investigated the effect of the 18S RNA-Nano-flare probe on the development of cloned embryos after SCNT. The cytotoxic effect of the 18S RNA-Nano-flare probe on porcine fetal fibroblasts was dose-dependent, and 18S RNA was detected using the 18S RNA-Nano-flare probe. In addition, treating donor cells with 500 pM 18S RNA-Nano-flare probe did not have adverse effects on the development of SCNT embryos at the pre-implantation stage. In conclusion, we established a preliminary platform to detect RNA in live donor cells using a Nano-flare probe prior to SCNT.

  9. Probing a Structural Model of the Nuclear Pore Complex Channel through Molecular Dynamics

    PubMed Central

    Miao, Lingling; Schulten, Klaus

    2010-01-01

    Abstract The central pore of a nuclear pore complex (NPC) is filled with unstructured proteins that contain many FG-repeats separated by hydrophilic regions. An example of such protein is nsp1. By simulating an array of nsp1 segments, we identified, in an earlier study, a spontaneously formed brushlike structure that promises to explain selective transport in the NPC channel. Here we report four (350,000 atom, 200 ns) simulations probing this structure via its interaction with transport receptor NTF2 as well as with an inert protein. NTF2 dimers are observed to gradually enter the brush, but the inert protein is not. Both NTF2 and the inert protein are found to bind to FG-repeats, but binding periods lasted more briefly for the inert protein. A simulation also investigated the behavior of a brush made of mutant nsp1 that is known to be less effective in NPC-selective transport, finding that this brush does not attract NTF2. PMID:20409487

  10. A Nuclear Receptor Ligand-based Probe Enables Temporal Control of C. elegans Development

    PubMed Central

    Judkins, Joshua C.; Mahanti, Parag; Hoffman, Jacob; Yim, Isaiah; Antebi, Adam; Schroeder, Frank C.

    2014-01-01

    C. elegans development and lifespan are controlled by the nuclear hormone receptor DAF-12, an important model for vertebrate vitamin D and liver-X receptors. Similar to its mammalian homologs, DAF-12 function is regulated by bile acid-like steroidal ligands, the dafachronic acids; however, tools for investigating their biosynthesis and function in vivo are lacking. We report a flexible synthesis for DAF-12 ligands and masked ligand derivatives that enable precise temporal control of DAF-12 function. For ligand masking, we introduce photocleavable amides of 5-methoxy-N-methyl-2-nitroaniline (MMNA). MMNA-masked ligands are bioavailable and after incorporation into the worm can be used to trigger expression of DAF-12 target genes and initiate development from dauer larvae to adults by brief, innocuous UV-irradiation. In-vivo release of DAF-12 ligands and other small-molecule signals using MMNA-based probes will enable functional studies with precise spatial and temporal resolution. PMID:24453122

  11. Supplements for exotic pets.

    PubMed

    Mejia-Fava, Johanna; Colitz, Carmen M H

    2014-09-01

    The use of supplements has become commonplace in an effort to complement traditional therapy and as part of long-term preventive health plans. This article discusses historical and present uses of antioxidants, vitamins, and herbs. By complementing traditional medicine with holistic and alternative nutrition and supplements, the overall health and wellness of exotic pets can be enhanced and balanced. Further research is needed for understanding the strengths and uses of supplements in exotic species. Going back to the animals' origin and roots bring clinicians closer to nature and its healing powers.

  12. Dynamical effects in fusion with exotic nuclei

    NASA Astrophysics Data System (ADS)

    Vo-Phuoc, K.; Simenel, C.; Simpson, E. C.

    2016-08-01

    Background: Reactions with stable beams have demonstrated strong interplay between nuclear structure and fusion. Exotic beam facilities open new perspectives to understand the impact of neutron skin, large isospin, and weak binding energies on fusion. Microscopic theories of fusion are required to guide future experiments. Purpose: To investigate new effects of exotic structures and dynamics in near-barrier fusion with exotic nuclei. Method: Microscopic approaches based on the Hartree-Fock (HF) mean-field theory are used for studying fusion barriers in -54Ca40+116Sn reactions for even isotopes. Bare potential barriers are obtained assuming frozen HF ground-state densities. Dynamical effects on the barrier are accounted for in time-dependent Hartree-Fock (TDHF) calculations of the collisions. Vibrational couplings are studied in the coupled-channel framework and near-barrier nucleon transfer is investigated with TDHF calculations. Results: The development of a neutron skin in exotic calcium isotopes strongly lowers the bare potential barrier. However, this static effect is not apparent when dynamical effects are included. On the contrary, a fusion hindrance is observed in TDHF calculations with the most neutron-rich calcium isotopes which cannot be explained by vibrational couplings. Transfer reactions are also important in these systems due to charge equilibration processes. Conclusions: Despite its impact on the bare potential, the neutron skin is not seen as playing an important role in the fusion dynamics. However, the charge transfer with exotic projectiles could lead to an increase of the Coulomb repulsion between the fragments, suppressing fusion. The effects of transfer and dissipative mechanisms on fusion with exotic nuclei deserve further studies.

  13. 33S nuclear magnetic resonance spectroscopy of biological samples obtained with a laboratory model 33S cryogenic probe.

    PubMed

    Hobo, Fumio; Takahashi, Masato; Saito, Yuta; Sato, Naoki; Takao, Tomoaki; Koshiba, Seizo; Maeda, Hideaki

    2010-05-01

    (33)S nuclear magnetic resonance (NMR) spectroscopy is limited by inherently low NMR sensitivity because of the quadrupolar moment and low gyromagnetic ratio of the (33)S nucleus. We have developed a 10 mm (33)S cryogenic NMR probe, which is operated at 9-26 K with a cold preamplifier and a cold rf switch operated at 60 K. The (33)S NMR sensitivity of the cryogenic probe is as large as 9.8 times that of a conventional 5 mm broadband NMR probe. The (33)S cryogenic probe was applied to biological samples such as human urine, bile, chondroitin sulfate, and scallop tissue. We demonstrated that the system can detect and determine sulfur compounds having SO(4)(2-) anions and -SO(3)(-) groups using the (33)S cryogenic probe, as the (33)S nuclei in these groups are in highly symmetric environments. The NMR signals for other common sulfur compounds such as cysteine are still undetectable by the (33)S cryogenic probe, as the (33)S nuclei in these compounds are in asymmetric environments. If we shorten the rf pulse width or decrease the rf coil diameter, we should be able to detect the NMR signals for these compounds.

  14. Glueballs, Hybrids and Exotics

    SciTech Connect

    Reyes, M. A.; Moreno, G.

    2006-09-25

    We comment on the physics analysis carried out by the Experimental High Energy Physics (EHEP) group of the Instituto de Fisica of the University of Guanajuato (IFUG), Mexico. In particular, this group has been involved in analysis carried out to search for glueball, hybrid and exotic candidates.

  15. Cusps and exotic charmonia

    NASA Astrophysics Data System (ADS)

    Swanson, E. S.

    2016-06-01

    A simple, causal and analytic model of final state rescattering is used to describe all available data on the exotic resonances Zc(3900) and Zc(4025). The model provides a compelling and accurate representation of experiment with no need for poles in the scattering matrix.

  16. Exotic nonrelativistic string

    SciTech Connect

    Casalbuoni, Roberto; Gomis, Joaquim; Longhi, Giorgio

    2007-12-15

    We construct a classical nonrelativistic string model in 3+1 dimensions. The model contains a spurion tensor field that is responsible for the noncommutative structure of the model. Under double-dimensional reduction the model reduces to the exotic nonrelativistic particle in 2+1 dimensions.

  17. Light Exotic Mesons

    NASA Astrophysics Data System (ADS)

    Eugenio, Paul

    2016-03-01

    tudies of meson spectra via strong decays provide insight regarding QCD at the confinement scale. These studies have led to phenomenological models for QCD such as the constituent quark model. However, QCD allows for a much richer spectrum of meson states which include extra states such as hybrids, exotics, multi-quarks, and glueballs. Within the past two decades a number of experiments have put forth tantalizing evidence for the existence of light quark exotic hybrid mesons in the mass range below 2 GeV . Recent Lattice QCD calculations of the light-quark meson spectrum indicate a constituent gluon-like excitation contributing an additional JPC =1+- and mass 1 - 1 . 5 GeV resulting in the lightest hybrid nonets with masses near 2 . 0 GeV . High statistical yields from recent experiments along with new advances in analysis techniques have shed a new light towards the understanding the latest experimental exotic candidates. Recent results from hadro-production and photo-production will be presented followed by an overview of ongoing and future efforts to search for light exotic mesons.

  18. Development of a magic-angle spinning nuclear magnetic resonance probe with a cryogenic detection system for sensitivity enhancement.

    PubMed

    Mizuno, Takashi; Hioka, Katsuya; Fujioka, Koji; Takegoshi, K

    2008-04-01

    A novel nuclear magnetic resonance (NMR) probe for high-resolution solid-state NMR has been developed. In this probe, temperature of the detection coil is kept at cryogenic temperature (approximately 12 K) for sensitivity enhancement, which is achieved not only by suppression of thermal noise but also by increment of a Q factor of the coil. A marked feature of this probe is that a sample rotating at magic angle is thermally isolated from the cryogenic system in order to realize high-resolution solid-state NMR measurement at various sample temperatures. We call this system as cryocoil magic-angle spinning (cryocoil MAS). (1)H MAS NMR with the coil temperature of approximately 20 K was successfully observed for solid adamantane rotating at room temperature, and signal-to-noise increment due to this cryocoil approach was confirmed.

  19. Probing and Exploiting the Interplay between Nuclear and Electronic Motion in Charge Transfer Processes.

    PubMed

    Delor, Milan; Sazanovich, Igor V; Towrie, Michael; Weinstein, Julia A

    2015-04-21

    The Born-Oppenheimer approximation refers to the assumption that the nuclear and electronic wave functions describing a molecular system evolve and can be determined independently. It is now well-known that this approximation often breaks down and that nuclear-electronic (vibronic) coupling contributes greatly to the ultrafast photophysics and photochemistry observed in many systems ranging from simple molecules to biological organisms. In order to probe vibronic coupling in a time-dependent manner, one must use spectroscopic tools capable of correlating the motions of electrons and nuclei on an ultrafast time scale. Recent developments in nonlinear multidimensional electronic and vibrational spectroscopies allow monitoring both electronic and structural factors with unprecedented time and spatial resolution. In this Account, we present recent studies from our group that make use of different variants of frequency-domain transient two-dimensional infrared (T-2DIR) spectroscopy, a pulse sequence combining electronic and vibrational excitations in the form of a UV-visible pump, a narrowband (12 cm(-1)) IR pump, and a broadband (400 cm(-1)) IR probe. In the first example, T-2DIR is used to directly compare vibrational dynamics in the ground and relaxed electronic excited states of Re(Cl)(CO)3(4,4'-diethylester-2,2'-bipyridine) and Ru(4,4'-diethylester-2,2'-bipyridine)2(NCS)2, prototypical charge transfer complexes used in photocatalytic CO2 reduction and electron injection in dye-sensitized solar cells. The experiments show that intramolecular vibrational redistribution (IVR) and vibrational energy transfer (VET) are up to an order of magnitude faster in the triplet charge transfer excited state than in the ground state. These results show the influence of electronic arrangement on vibrational coupling patterns, with direct implications for vibronic coupling mechanisms in charge transfer excited states. In the second example, we show unambiguously that electronic and

  20. Few-second-long correlation times in a quantum dot nuclear spin bath probed by frequency-comb nuclear magnetic resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Waeber, A. M.; Hopkinson, M.; Farrer, I.; Ritchie, D. A.; Nilsson, J.; Stevenson, R. M.; Bennett, A. J.; Shields, A. J.; Burkard, G.; Tartakovskii, A. I.; Skolnick, M. S.; Chekhovich, E. A.

    2016-07-01

    One of the key challenges in spectroscopy is the inhomogeneous broadening that masks the homogeneous spectral lineshape and the underlying coherent dynamics. Techniques such as four-wave mixing and spectral hole-burning are used in optical spectroscopy, and spin-echo in nuclear magnetic resonance (NMR). However, the high-power pulses used in spin-echo and other sequences often create spurious dynamics obscuring the subtle spin correlations important for quantum technologies. Here we develop NMR techniques to probe the correlation times of the fluctuations in a nuclear spin bath of individual quantum dots, using frequency-comb excitation, allowing for the homogeneous NMR lineshapes to be measured without high-power pulses. We find nuclear spin correlation times exceeding one second in self-assembled InGaAs quantum dots--four orders of magnitude longer than in strain-free III-V semiconductors. This observed freezing of the nuclear spin fluctuations suggests ways of designing quantum dot spin qubits with a well-understood, highly stable nuclear spin bath.

  1. Nuclear Quadrupole Resonance (NQR) Method and Probe for Generating RF Magnetic Fields in Different Directions to Distinguish NQR from Acoustic Ringing Induced in a Sample

    DTIC Science & Technology

    1997-08-01

    77,719 TITLE OF THE INVENTION NUCLEAR QUADRUPOLE RESONANCE ( NQR ) METHOD AND PROBE FOR GENERATING RF MAGNETIC FIELDS IN DIFFERENT DIRECTIONS TO...DISTINGUISH NQR FROM ACOUSTIC RINGING INDUCED IN A SAMPLE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a...nuclear quadrupole 15 resonance ( NQR ) method and probe for generating RF magnetic fields in different directions towards a sample. More specifically

  2. Single point aerosol sampling: Evaluation of mixing and probe performance in a nuclear stack

    SciTech Connect

    Rodgers, J.C.; Fairchild, C.I.; Wood, G.O.

    1995-02-01

    Alternative Reference Methodologies (ARMs) have been developed for sampling of radionuclides from stacks and ducts that differ from the methods required by the U.S. EPA. The EPA methods are prescriptive in selection of sampling locations and in design of sampling probes whereas the alternative methods are performance driven. Tests were conducted in a stack at Los Alamos National Laboratory to demonstrate the efficacy of the ARMs. Coefficients of variation of the velocity tracer gas, and aerosol particle profiles were determined at three sampling locations. Results showed numerical criteria placed upon the coefficients of variation by the ARMs were met at sampling stations located 9 and 14 stack diameters from flow entrance, but not at a location that is 1.5 diameters downstream from the inlet. Experiments were conducted to characterize the transmission of 10 {mu}m aerodynamic equivalent diameter liquid aerosol particles through three types of sampling probes. The transmission ratio (ratio of aerosol concentration at the probe exit plane to the concentration in the free stream) was 107% for a 113 L/min (4-cfm) anisokinetic shrouded probe, but only 20% for an isokinetic probe that follows the EPA requirements. A specially designed isokinetic probe showed a transmission ratio of 63%. The shrouded probe performance would conform to the ARM criteria; however, the isokinetic probes would not.

  3. Probing the nuclear and circumnuclear activity of NGC 1365 in the infrared

    NASA Astrophysics Data System (ADS)

    Alonso-Herrero, A.; Sánchez-Portal, M.; Ramos Almeida, C.; Pereira-Santaella, M.; Esquej, P.; García-Burillo, S.; Castillo, M.; González-Martín, O.; Levenson, N.; Hatziminaoglou, E.; Acosta-Pulido, J. A.; González-Serrano, J. I.; Pović, M.; Packham, C.; Pérez-García, A. M.

    2012-09-01

    We present new far-infrared (70-500 μm) Herschel Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) imaging observations as well as new mid-IR Gemini/Thermal-Region Camera Spectrograph imaging (8.7 and 18.3 μm) and spectroscopy of the inner Lindblad resonance (ILR) region (R < 2.5 kpc) of the spiral galaxy NGC 1365. We complemented these observations with archival Spitzer imaging and spectral mapping observations. The ILR region of NGC 1365 contains a Seyfert 1.5 nucleus and a ring of star formation with an approximate diameter of 2 kpc. The strong star formation activity in the ring is resolved by the Herschel/PACS imaging data, as well as by the Spitzer 24 μm continuum emission, [Ne II] 12.81 μm line emission, and 6.2 and 11.3 μm PAH emission. The active galactic nucleus (AGN) is the brightest source in the central regions up to λ ˜ 24 μm, but it becomes increasingly fainter in the far-infrared when compared to the emission originating in the infrared clusters (or groups of them) located in the ring. We modelled the AGN unresolved infrared emission with the clumpy torus models and estimated that the AGN contributes only to a small fraction (˜5 per cent) of the infrared emission produced in the inner ˜5 kpc. We fitted the non-AGN 24-500 μm spectral energy distribution of the ILR region and found that the dust temperatures and mass are similar to those of other nuclear and circumnuclear starburst regions. Finally we showed that within the ILR region of NGC 1365, most of the ongoing star formation activity is taking place in dusty regions as probed by the 24 μm emission. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Augusto González Linares Senior Research Fellow.

  4. Vertical nanopillars for in situ probing of nuclear mechanics in adherent cells

    NASA Astrophysics Data System (ADS)

    Hanson, Lindsey; Zhao, Wenting; Lou, Hsin-Ya; Lin, Ziliang Carter; Lee, Seok Woo; Chowdary, Praveen; Cui, Yi; Cui, Bianxiao

    2015-06-01

    The mechanical stability and deformability of the cell nucleus are crucial to many biological processes, including migration, proliferation and polarization. In vivo, the cell nucleus is frequently subjected to deformation on a variety of length and time scales, but current techniques for studying nuclear mechanics do not provide access to subnuclear deformation in live functioning cells. Here we introduce arrays of vertical nanopillars as a new method for the in situ study of nuclear deformability and the mechanical coupling between the cell membrane and the nucleus in live cells. Our measurements show that nanopillar-induced nuclear deformation is determined by nuclear stiffness, as well as opposing effects from actin and intermediate filaments. Furthermore, the depth, width and curvature of nuclear deformation can be controlled by varying the geometry of the nanopillar array. Overall, vertical nanopillar arrays constitute a novel approach for non-invasive, subcellular perturbation of nuclear mechanics and mechanotransduction in live cells.

  5. Vertical nanopillars for in situ probing of nuclear mechanics in adherent cells

    PubMed Central

    Hanson, Lindsey; Zhao, Wenting; Lou, Hsin-Ya; Lin, Ziliang Carter; Lee, Seok Woo; Chowdary, Praveen; Cui, Yi; Cui, Bianxiao

    2016-01-01

    The mechanical stability and deformability of the cell nucleus are crucial to many biological processes, including migration, proliferation and polarization. In vivo, the cell nucleus is frequently subjected to deformation on a variety of length and time scales, but current techniques for studying nuclear mechanics do not provide access to subnuclear deformation in live functioning cells. Here we introduce arrays of vertical nanopillars as a new method for the in situ study of nuclear deformability and the mechanical coupling between the cell membrane and the nucleus in live cells. Our measurements show that nanopillar-induced nuclear deformation is determined by nuclear stiffness, as well as opposing effects from actin and intermediate filaments. Furthermore, the depth, width and curvature of nuclear deformation can be controlled by varying the geometry of the nanopillar array. Overall, vertical nanopillar arrays constitute a novel approach for non-invasive, subcellular perturbation of nuclear mechanics and mechanotransduction in live cells. PMID:25984833

  6. Vertical nanopillars for in situ probing of nuclear mechanics in adherent cells.

    PubMed

    Hanson, Lindsey; Zhao, Wenting; Lou, Hsin-Ya; Lin, Ziliang Carter; Lee, Seok Woo; Chowdary, Praveen; Cui, Yi; Cui, Bianxiao

    2015-06-01

    The mechanical stability and deformability of the cell nucleus are crucial to many biological processes, including migration, proliferation and polarization. In vivo, the cell nucleus is frequently subjected to deformation on a variety of length and time scales, but current techniques for studying nuclear mechanics do not provide access to subnuclear deformation in live functioning cells. Here we introduce arrays of vertical nanopillars as a new method for the in situ study of nuclear deformability and the mechanical coupling between the cell membrane and the nucleus in live cells. Our measurements show that nanopillar-induced nuclear deformation is determined by nuclear stiffness, as well as opposing effects from actin and intermediate filaments. Furthermore, the depth, width and curvature of nuclear deformation can be controlled by varying the geometry of the nanopillar array. Overall, vertical nanopillar arrays constitute a novel approach for non-invasive, subcellular perturbation of nuclear mechanics and mechanotransduction in live cells.

  7. Promoting the exotic pet practice.

    PubMed

    Harris, Don J

    2005-09-01

    The marketing and promotion of an exotic pet veterinary practice allows the use of strategies that are not necessarily available in other veterinary disciplines. The advantage that an exotics practice enjoys is that it is able to capitalize not only on the unique nature of the species being attended but also on the specialized features of the hospital itself that make it specifically appropriate in caring for exotic pets. Before marketing, however, comes the responsibility that the practice live up to the claims made in promotional materials. A practice cannot ethically be presented as an "exotics" practice if it is nothing more than a dog and cat facility that is willing to attend to exotic pets. It is the competence of the veterinary staff and the appropriateness of the facility that determines the suitability of the practice for exotics management.

  8. Exotic quarks in Twin Higgs models

    SciTech Connect

    Cheng, Hsin -Chia; Jung, Sunghoon; Salvioni, Ennio; Tsai, Yuhsin

    2016-03-14

    The Twin Higgs model provides a natural theory for the electroweak symmetry breaking without the need of new particles carrying the standard model gauge charges below a few TeV. In the low energy theory, the only probe comes from the mixing of the Higgs fields in the standard model and twin sectors. However, an ultraviolet completion is required below ~ 10 TeV to remove residual logarithmic divergences. In non-supersymmetric completions, new exotic fermions charged under both the standard model and twin gauge symmetries have to be present to accompany the top quark, thus providing a high energy probe of the model. Some of them carry standard model color, and may therefore be copiously produced at current or future hadron colliders. Once produced, these exotic quarks can decay into a top together with twin sector particles. If the twin sector particles escape the detection, we have the irreducible stop-like signals. On the other hand, some twin sector particles may decay back into the standard model particles with long lifetimes, giving spectacular displaced vertex signals in combination with the prompt top quarks. This happens in the Fraternal Twin Higgs scenario with typical parameters, and sometimes is even necessary for cosmological reasons. We study the potential displaced vertex signals from the decays of the twin bottomonia, twin glueballs, and twin leptons in the Fraternal Twin Higgs scenario. As a result, depending on the details of the twin sector, the exotic quarks may be probed up to ~ 2.5 TeV at the LHC and beyond 10 TeV at a future 100 TeV collider, providing a strong test of this class of ultraviolet completions.

  9. Exotic quarks in Twin Higgs models

    DOE PAGES

    Cheng, Hsin -Chia; Jung, Sunghoon; Salvioni, Ennio; ...

    2016-03-14

    The Twin Higgs model provides a natural theory for the electroweak symmetry breaking without the need of new particles carrying the standard model gauge charges below a few TeV. In the low energy theory, the only probe comes from the mixing of the Higgs fields in the standard model and twin sectors. However, an ultraviolet completion is required below ~ 10 TeV to remove residual logarithmic divergences. In non-supersymmetric completions, new exotic fermions charged under both the standard model and twin gauge symmetries have to be present to accompany the top quark, thus providing a high energy probe of themore » model. Some of them carry standard model color, and may therefore be copiously produced at current or future hadron colliders. Once produced, these exotic quarks can decay into a top together with twin sector particles. If the twin sector particles escape the detection, we have the irreducible stop-like signals. On the other hand, some twin sector particles may decay back into the standard model particles with long lifetimes, giving spectacular displaced vertex signals in combination with the prompt top quarks. This happens in the Fraternal Twin Higgs scenario with typical parameters, and sometimes is even necessary for cosmological reasons. We study the potential displaced vertex signals from the decays of the twin bottomonia, twin glueballs, and twin leptons in the Fraternal Twin Higgs scenario. As a result, depending on the details of the twin sector, the exotic quarks may be probed up to ~ 2.5 TeV at the LHC and beyond 10 TeV at a future 100 TeV collider, providing a strong test of this class of ultraviolet completions.« less

  10. Relativistic Energy Density Functionals: Exotic modes of excitation

    SciTech Connect

    Vretenar, D.; Paar, N.; Marketin, T.

    2008-11-11

    The framework of relativistic energy density functionals has been applied to the description of a variety of nuclear structure phenomena, not only in spherical and deformed nuclei along the valley of {beta}-stability, but also in exotic systems with extreme isospin values and close to the particle drip-lines. Dynamical aspects of exotic nuclear structure have been investigated with the relativistic quasiparticle random-phase approximation. We present results for the evolution of low-lying dipole (pygmy) strength in neutron-rich nuclei, and charged-current neutrino-nucleus cross sections.

  11. Probing nuclear symmetry energy at high densities using pion, kaon, eta and photon productions in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Xiao, Zhi-Gang; Yong, Gao-Chan; Chen, Lie-Wen; Li, Bao-An; Zhang, Ming; Xiao, Guo-Qing; Xu, Nu

    2014-02-01

    The high-density behavior of nuclear symmetry energy is among the most uncertain properties of dense neutron-rich matter. Its accurate determination has significant ramifications in understanding not only the reaction dynamics of heavy-ion reactions, especially those induced by radioactive beams, but also many interesting phenomena in astrophysics, such as the explosion mechanism of supernova and the properties of neutron stars. The heavy-ion physics community has devoted much effort during the last few years to constrain the high-density symmetry using various probes. In particular, the / ratio has been most extensively studied both theoretically and experimentally. All models have consistently predicted qualitatively that the / ratio is a sensitive probe of the high-density symmetry energy especially with beam energies near the pion production threshold. However, the predicted values of the / ratio are still quite model dependent mostly because of the complexity of modeling pion production and reabsorption dynamics in heavy-ion collisions, leading to currently still controversial conclusions regarding the high-density behavior of nuclear symmetry energy from comparing various model calculations with available experimental data. As more / data become available and a deeper understanding about the pion dynamics in heavy-ion reactions is obtained, more penetrating probes, such as the K +/ K 0 ratio, meson and high-energy photons are also being investigated or planned at several facilities. Here, we review some of our recent contributions to the community effort of constraining the high-density behavior of nuclear symmetry energy in heavy-ion collisions. In addition, the status of some worldwide experiments for studying the high-density symmetry energy, including the HIRFL-CSR external target experiment (CEE) are briefly introduced.

  12. Electromagnetic ultrasonic (EMUS) probes: State of the art and developments for application in nuclear power plants

    SciTech Connect

    Salzburger, H.J.; Huebschen, G.; Kroening, M.

    1994-12-31

    The excitation and detection of ultrasound by conventional piezoelectric techniques doesn`t provide the full range of elastic wave modes which can be used for NDT. Besides this there is a limitation of the temperature range. This gap can be filled up using alternative techniques for the ultrasonic transduction. One of the most far developed alternative techniques is the electromagnetic ultrasonic (EMUS) excitation and detection. EMUS-probes work free of liquid couplants; hence they can be applied for inspection and measurements at higher temperatures. The transduction of Shear waves with horizontal polarization (SH-)waves can be more reliably performed by EMUS-probes for practical applications than by piezoelectric shear wave transducers using Y-cut quartz. The contribution presents the performance of Phased-Array angle-probes. The application of these probe-type for the ISI of austenitic and dissimilar welds using SH-waves will be shortly highlighted. For the continuous monitoring of the liquid level in the vessels of BWR`s from outside at temperatures of 300 C SV-wave angle probes are used. Their performance for operation in the mentioned temperature range and the principle of measurement of the liquid level will be described. Ongoing development work to enlarge the frequency range of EMUS-probes and for the automatic control of the lift-off will be shortly described.

  13. Investigation of a MMP-2 Activity-Dependent Anchoring Probe for Nuclear Imaging of Cancer

    PubMed Central

    Temma, Takashi; Hanaoka, Hirofumi; Yonezawa, Aki; Kondo, Naoya; Sano, Kohei; Sakamoto, Takeharu; Seiki, Motoharu; Ono, Masahiro; Saji, Hideo

    2014-01-01

    Purpose Since matrix metalloproteinase-2 (MMP-2) is an important marker of tumor malignancy, we developed an original drug design strategy, MMP-2 activity dependent anchoring probes (MDAP), for use in MMP-2 activity imaging, and evaluated the usefulness of this probe in in vitro and in vivo experiments. Methods We designed and synthesized MDAP1000, MDAP3000, and MDAP5000, which consist of 4 independent moieties: RI unit (111In hydrophilic chelate), MMP-2 substrate unit (short peptide), anchoring unit (alkyl chain), and anchoring inhibition unit (polyethylene glycol (PEGn; where n represents the approximate molecular weight, n = 1000, 3000, and 5000). Probe cleavage was evaluated by chromatography after MMP-2 treatment. Cellular uptake of the probes was then measured. Radioactivity accumulation in tumor xenografts was evaluated after intravenous injection of the probes, and probe cleavage was evaluated in tumor homogenates. Results MDAP1000, MDAP3000, and MDAP5000 were cleaved by MMP-2 in a concentration-dependent manner. MDAP3000 pretreated with MMP-2 showed higher accumulation in tumor cells, and was completely blocked by additional treatment with an MMP inhibitor. MDAP3000 exhibited rapid blood clearance and a high tumor accumulation after intravenous injection in a rodent model. Furthermore, pharmacokinetic analysis revealed that MDAP3000 exhibited a considerably slow washout rate from tumors to blood. A certain fraction of cleaved MDAP3000 existed in tumor xenografts in vivo. Conclusions The results indicate the possible usefulness of our MDAP strategy for tumor imaging. PMID:25010662

  14. Probing nuclear dynamics of oriented HeH+ with odd-even high-order harmonics

    NASA Astrophysics Data System (ADS)

    Li, W. Y.; Yu, S. J.; Wang, S.; Chen, Y. J.

    2016-11-01

    We study the electron-nuclear coupled dynamics for oriented HeH+ molecules in strong laser fields numerically and analytically. At small orientation angles, the asymmetric molecule tends to stretch to distances larger than the equilibrium separation and strong even harmonics are emitted. We show that the permanent dipole of the system plays an important role in the vibrational dynamics of the nuclear wave packet. The nuclear motion and the molecular structure can be read from the spectra and ellipticity of odd-even high harmonics. Our results also have implications for strong-field ionization of the asymmetric system.

  15. Beat-to-beat left ventricular performance in atrial fibrillation: radionuclide assessment with the computerized nuclear probe

    SciTech Connect

    Schneider, J.; Berger, H.J.; Sands, M.J.; Lachman, A.B.; Zaret, B.L.

    1983-04-01

    There is wide beat-to-beat variability in cycle length and left ventricular performance in patients with atrial fibrillation. In this study, left ventricular ejection fraction and relative left ventricular volumes were evaluated on a beat-to-beat basis with the computerized nuclear probe, an instrument with sufficiently high sensitivity to allow continuous evaluation of the radionuclide time-activity curve. Of 18 patients with atrial fibrillation, 5 had mitral stenosis, 6 had mitral regurgitation, and 7 had coronary artery disease. Fifty consecutive beats were analyzed in each patient. The mean left ventricular ejection fraction ranged from 17 to 51%. There was substantial beat-to-beat variation in cycle length and left ventricular ejection fraction in all patients, including those with marked left ventricular dysfunction. In 14 patients who also underwent multiple gated cardiac blood pool imaging, there was an excellent correlation between mean ejection fraction derived from the nuclear probe and gated ejection fraction obtained by gamma camera imaging (r . 0.90). Based on beat-to-beat analysis, left ventricular function was dependent on relative end-diastolic volume and multiple preceding cycle lengths, but not preceding end-systolic volumes. This study demonstrates that a single value for left ventricular ejection fraction does not adequately characterize left ventricular function in patients with atrial fibrillation. Furthermore, both the mean beat-to-beat and the gated ejection fraction may underestimate left ventricular performance at rest in such patients.

  16. Probing the Strength of Nuclear-Plasma Interactions at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Ratkiewicz, A.; Berzak Hopkins, L.; Bleuel, D. L.; Cassata, W. S.; London, R.; Velsko, C. A.; Yeamans, C. B.; Bernstein, L. A.; van Bibber, K.; Goldblum, B. L.; Siem, S.; Weideking, M.

    2016-09-01

    Electron-mediated interactions between nuclei and plasma are expected to affect nuclear reaction cross sections in High Energy Density Plasmas (HEDPs), which are the environment in which stellar nucleosynthesis occurs. However, attempts to measure the strength of these Nuclear Plasma Interactions (NPIs) have been hindered by the extreme narrowness of the nuclear transition (Γ <= 1 μeV). We report on the planned effort to measure the strength of this effect in HEDPs to be produced at the National Ignition Facility (NIF) by inducing NPIs on highly-excited (1-5 MeV) nuclear states of 133Xe produced in the (n,2n) reaction with 134Xe in the NIF target. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  17. Nuclear responses for double-beta decays by hadron, photon, and neutrino probes and MOON experiment

    NASA Astrophysics Data System (ADS)

    Ejiri, H.

    2006-05-01

    Neutrino-less double-beta decays (0νββ) with the mass sensitivities of the solar and atmospheric ν masses are of great interest for studying the Majorana nature of neutrinos and the absolute mass spectrum as suggested by recent ν oscillation experiments. Here nuclear responses (nuclear matrix elements) for 0νββ are crucial. They are well studied experimentally by using charge-exchange, photo-nuclear and neutrino reactions. MOON(Mo Observatory Of Neutrinos) is a high sensitivity 0νβ β experiment with the mass sensitivity of an order of 30 meV. Experimental studies of the nuclear responses and the present status of MOON are briefly discussed.

  18. Complementary optical and nuclear imaging of caspase-3 activity using combined activatable and radio-labeled multimodality molecular probe

    NASA Astrophysics Data System (ADS)

    Lee, Hyeran; Akers, Walter J.; Cheney, Philip P.; Edwards, W. Barry; Liang, Kexian; Culver, Joseph P.; Achilefu, Samuel

    2009-07-01

    Based on the capability of modulating fluorescence intensity by specific molecular events, we report a new multimodal optical-nuclear molecular probe with complementary reporting strategies. The molecular probe (LS498) consists of tetraazacyclododecanetetraacetic acid (DOTA) for chelating a radionuclide, a near-infrared fluorescent dye, and an efficient quencher dye. The two dyes are separated by a cleavable peptide substrate for caspase-3, a diagnostic enzyme that is upregulated in dying cells. LS498 is radiolabeled with 64Cu, a radionuclide used in positron emission tomography. In the native form, LS498 fluorescence is quenched until caspase-3 cleavage of the peptide substrate. Enzyme kinetics assay shows that LS498 is readily cleaved by caspase-3, with excellent enzyme kinetic parameters kcat and KM of 0.55+/-0.01 s-1 and 1.12+/-0.06 μM, respectively. In mice, the initial fluorescence of LS498 is ten-fold less than control. Using radiolabeled 64Cu-LS498 in a controlled and localized in-vivo model of caspase-3 activation, a time-dependent five-fold NIR fluorescence enhancement is observed, but radioactivity remains identical in caspase-3 positive and negative controls. These results demonstrate the feasibility of using radionuclide imaging for localizing and quantifying the distribution of molecular probes and optical imaging for reporting the functional status of diagnostic enzymes.

  19. Discovering uncolored naturalness in exotic Higgs decays

    NASA Astrophysics Data System (ADS)

    Curtin, David; Verhaaren, Christopher B.

    2015-12-01

    Solutions to the hierarchy problem usually require top partners. In standard SUSY or composite Higgs theories, the partners carry SM color and are becoming increasingly constrained by LHC searches. However, theories like Folded SUSY (FS), Twin Higgs (TH) and Quirky Little Higgs (QLH) introduce uncolored top partners, which can be SM singlets or carry electroweak charge. Their small production cross section left doubt as to whether the LHC can effectively probe such scenarios. Typically, these partners are charged under their own mirror color gauge group. In FS and QLH, the absence of light mirror matter allows glueballs to form at the bottom of the mirror spectrum. This is also the case in some TH realizations. The Higgs can decay to these mirror glueballs, with the glueballs decaying into SM particles with potentially observable lifetimes. We undertake the first detailed study of this glueball signature and quantitatively demonstrate the discovery potential of uncolored naturalness via exotic Higgs decays at the LHC and a potential future 100TeV collider. Our findings indicate that mirror glueballs are the smoking gun signature of natural FS and QLH type theories, in analogy to tree-level Higgs coupling shifts for the TH. We show that glueball masses in the ˜ 10-60 GeV mass range are theoretically preferred. Careful treatment of lifetime, mirror-hadronization and non-perturbative uncertainties is required to perform meaningful collider studies. We outline several new search strategies for exotic Higgs decays of the form h → XX → 4 f at the LHC, with X having lifetimes in the 10 μm to km range. We find that FS stops can be probed with masses up to 600 (1100) GeV at the LHC with 300 (3000) fb-1 of data, and TH top partners could be accessible with masses up to 900 (1500) GeV. This makes exotic Higgs decays the prime discovery channel for uncolored naturalness at the LHC.

  20. Probing the equation of state of nuclear matter via neutron star asteroseismology.

    PubMed

    Sotani, Hajime; Nakazato, Ken'ichiro; Iida, Kei; Oyamatsu, Kazuhiro

    2012-05-18

    We general-relativistically calculate the frequency of fundamental torsional oscillations of neutron star crusts, where we focus on the crystalline properties obtained from macroscopic nuclear models in a way that is dependent on the equation of state of nuclear matter. We find that the calculated frequency is sensitive to the density dependence of the symmetry energy, but almost independent of the incompressibility of symmetric nuclear matter. By identifying the lowest-frequency quasiperiodic oscillation in giant flares observed from soft gamma-ray repeaters as the fundamental torsional mode and allowing for the dependence of the calculated frequency on stellar models, we provide a lower limit of the density derivative of the symmetry energy as L≃50  MeV.

  1. Dissipative Dynamics with Exotic Beams

    NASA Astrophysics Data System (ADS)

    di Toro, M.; Colonna, M.; Greco, V.; Ferini, G.; Rizzo, C.; Rizzo, J.; Baran, V.; Wolter, H. H.; Zielinska-Pfabe, M.

    2008-04-01

    Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation and at high nucleon momenta. In this report we present a selection of reaction observables particularly sensitive to the isovector part of the interaction, i.e. to the symmetry term of the nuclear Equation of State (EoS) At low and Fermi energies the behavior of the symmetry energy around saturation influences dissipation and fragment production mechanisms. Predictions are shown for fusion, deep-inelastic and fragmentation collisions induced by neutron rich projectiles. At all energies the isospin transport data are supplying valuable information on value and slope of the symmetry term below saturation. The importance of studying violent collisions with radioactive beams in this energy range is finally stressed.

  2. Dynamic Isovector Reorientation of Deuteron as a Probe to Nuclear Symmetry Energy.

    PubMed

    Ou, Li; Xiao, Zhigang; Yi, Han; Wang, Ning; Liu, Min; Tian, Junlong

    2015-11-20

    We present the calculations on a novel reorientation effect of deuteron attributed to isovector interaction in the nuclear field of heavy target nuclei. The correlation angle determined by the relative momentum vector of the proton and the neutron originating from the breakup deuteron, which is experimentally detectable, exhibits significant dependence on the isovector nuclear potential but is robust against the variation of the isoscaler sector. In terms of sensitivity and cleanness, the breakup reactions induced by the polarized deuteron beam at about 100 MeV/u provide a more stringent constraint to the symmetry energy at subsaturation densities.

  3. Dynamic Isovector Reorientation of Deuteron as a Probe to Nuclear Symmetry Energy

    NASA Astrophysics Data System (ADS)

    Ou, Li; Xiao, Zhigang; Yi, Han; Wang, Ning; Liu, Min; Tian, Junlong

    2015-11-01

    We present the calculations on a novel reorientation effect of deuteron attributed to isovector interaction in the nuclear field of heavy target nuclei. The correlation angle determined by the relative momentum vector of the proton and the neutron originating from the breakup deuteron, which is experimentally detectable, exhibits significant dependence on the isovector nuclear potential but is robust against the variation of the isoscaler sector. In terms of sensitivity and cleanness, the breakup reactions induced by the polarized deuteron beam at about 100 MeV /u provide a more stringent constraint to the symmetry energy at subsaturation densities.

  4. γ production as a probe for early state dynamics in high energy nuclear collisions at RHIC

    DOE PAGES

    Liu, Yunpeng; Chen, Baoyi; Xu, Nu; ...

    2011-02-01

    γ production in heavy ion collisions at RHIC energy is investigated. While the transverse momentum spectra of the ground state γ(1s) are controlled by the initial state Cronin effect, the excited bb⁻ states are characterized by the competition between the cold and hot nuclear matter effects and sensitive to the dissociation temperatures determined by the heavy quark potential. We emphasize that it is necessary to measure the excited heavy quark states in order to extract the early stage information in high energy nuclear collisions at RHIC.

  5. THE COOLING OF THE CASSIOPEIA A NEUTRON STAR AS A PROBE OF THE NUCLEAR SYMMETRY ENERGY AND NUCLEAR PASTA

    SciTech Connect

    Newton, William G.; Hooker, Joshua; Li, Bao-An; Murphy, Kyleah

    2013-12-10

    X-ray observations of the neutron star (NS) in the Cas A supernova remnant over the past decade suggest the star is undergoing a rapid drop in surface temperature of ≈2%-5.5%. One explanation suggests the rapid cooling is triggered by the onset of neutron superfluidity in the core of the star, causing enhanced neutrino emission from neutron Cooper pair breaking and formation (PBF). Using consistent NS crust and core equations of state (EOSs) and compositions, we explore the sensitivity of this interpretation to the density dependence of the symmetry energy L of the EOS used, and to the presence of enhanced neutrino cooling in the bubble phases of crustal ''nuclear pasta''. Modeling cooling over a conservative range of NS masses and envelope compositions, we find L ≲ 70 MeV, competitive with terrestrial experimental constraints and other astrophysical observations. For masses near the most likely mass of M ≳ 1.65 M {sub ☉}, the constraint becomes more restrictive 35 ≲ L ≲ 55 MeV. The inclusion of the bubble cooling processes decreases the cooling rate of the star during the PBF phase, matching the observed rate only when L ≲ 45 MeV, taking all masses into consideration, corresponding to NS radii ≲ 11 km.

  6. The Cooling of the Cassiopeia A Neutron Star as a Probe of the Nuclear Symmetry Energy and Nuclear Pasta

    NASA Astrophysics Data System (ADS)

    Newton, William G.; Murphy, Kyleah; Hooker, Joshua; Li, Bao-An

    2013-12-01

    X-ray observations of the neutron star (NS) in the Cas A supernova remnant over the past decade suggest the star is undergoing a rapid drop in surface temperature of ≈2%-5.5%. One explanation suggests the rapid cooling is triggered by the onset of neutron superfluidity in the core of the star, causing enhanced neutrino emission from neutron Cooper pair breaking and formation (PBF). Using consistent NS crust and core equations of state (EOSs) and compositions, we explore the sensitivity of this interpretation to the density dependence of the symmetry energy L of the EOS used, and to the presence of enhanced neutrino cooling in the bubble phases of crustal "nuclear pasta." Modeling cooling over a conservative range of NS masses and envelope compositions, we find L <~ 70 MeV, competitive with terrestrial experimental constraints and other astrophysical observations. For masses near the most likely mass of M >~ 1.65 M ⊙, the constraint becomes more restrictive 35 <~ L <~ 55 MeV. The inclusion of the bubble cooling processes decreases the cooling rate of the star during the PBF phase, matching the observed rate only when L <~ 45 MeV, taking all masses into consideration, corresponding to NS radii <~ 11 km.

  7. The line-emitting gas in active galaxies - A probe of the nuclear engine

    NASA Technical Reports Server (NTRS)

    Veilleux, Sylvain

    1993-01-01

    This paper reviews some of the basic questions regarding the structure of the engine powering active galactic nuclei (AGN), the nature of the interaction between the AGN and the host galaxy, and the origin and evolution of AGN. The study of the dynamics and physical characteristics of the line-emitting gas in these objects has proven fruitful in addressing many of these issues. Recent advances in optical and infrared detector technology combined with the development of superior ground-based instruments have produced efficient new tools for the study of the line-emitting gas on nuclear and Galactic scales. Programs which take advantage of two of these new techniques, Fabry-Perot imaging spectroscopy and infrared spectroscopy, are described in this paper. The origin of nuclear activity in galaxies is also addressed in a third project which aims at determining the nature of luminous infrared galaxies.

  8. Highly selective detection of individual nuclear spins with rotary echo on an electron spin probe

    DOE PAGES

    Mkhitaryan, V. V.; Jelezko, F.; Dobrovitski, V. V.

    2015-10-26

    We consider an electronic spin, such as a nitrogen-vacancy center in diamond, weakly coupled to a large number of nuclear spins, and subjected to the Rabi driving with a periodically alternating phase. We show that by switching the driving phase synchronously with the precession of a given nuclear spin, the interaction to this spin is selectively enhanced, while the rest of the bath remains decoupled. The enhancement is of resonant character. The key feature of the suggested scheme is that the width of the resonance is adjustable, and can be greatly decreased by increasing the driving strength. Thus, the resonancemore » can be significantly narrowed, by a factor of 10–100 in comparison with the existing detection methods. Significant improvement in selectivity is explained analytically and confirmed by direct numerical many-spin simulations. As a result, the method can be applied to a wide range of solid-state systems.« less

  9. Probing nuclear motion by frequency modulation of molecular high-order harmonic generation.

    PubMed

    Bian, Xue-Bin; Bandrauk, André D

    2014-11-07

    Molecular high-order harmonic generation (MHOHG) in a non-Born-Oppenheimer treatment of H(2)(+), D(2)(+), is investigated by numerical simulations of the corresponding time-dependent Schrödinger equations in full dimensions. As opposed to previous studies on amplitude modulation of intracycle dynamics in MHOHG, we demonstrate redshifts as frequency modulation (FM) of intercycle dynamics in MHOHG. The FM is induced by nuclear motion using intense laser pulses. Compared to fixed-nuclei approximations, the intensity of MHOHG is much higher due to the dependence of enhanced ionization on the internuclear distance. The width and symmetry of the spectrum of each harmonic in MHOHG encode rich information on the dissociation process of molecules at the rising and falling parts of the laser pulses, which can be used to retrieve the nuclear dynamics. Isotope effects are studied to confirm the FM mechanism.

  10. Highly selective detection of individual nuclear spins with rotary echo on an electron spin probe

    SciTech Connect

    Mkhitaryan, V. V.; Jelezko, F.; Dobrovitski, V. V.

    2015-10-26

    We consider an electronic spin, such as a nitrogen-vacancy center in diamond, weakly coupled to a large number of nuclear spins, and subjected to the Rabi driving with a periodically alternating phase. We show that by switching the driving phase synchronously with the precession of a given nuclear spin, the interaction to this spin is selectively enhanced, while the rest of the bath remains decoupled. The enhancement is of resonant character. The key feature of the suggested scheme is that the width of the resonance is adjustable, and can be greatly decreased by increasing the driving strength. Thus, the resonance can be significantly narrowed, by a factor of 10–100 in comparison with the existing detection methods. Significant improvement in selectivity is explained analytically and confirmed by direct numerical many-spin simulations. As a result, the method can be applied to a wide range of solid-state systems.

  11. Disappearance of flow as a probe of the nuclear equation of state

    SciTech Connect

    Krofcheck, D.; Bauer, W.; Crawley, G.M.; Howden, S.; Ogilvie, C.A.; Vander Molen, A.; Westfall, G.D.; Wilson, W.K. ); Tickle, R.S. ); Djalali, C. ); Gale, C. )

    1992-10-01

    The disappearance of directed, collective nuclear motion ( flow'') away from the interaction region of heavy-ion collisions has been observed using the Lawrence Berkeley Laboratory Streamer Chamber. We find that flow vanishes at a beam energy near 50 MeV/nucleon for the {sup 139}La+{sup 139}La system and near 60 MeV/nucleon for the {sup 93}Nb+{sup 93}Nb system. The disappearance of flow may be understood as resulting from a balance between attractive and repulsive scattering strengths. Full calculations with the Boltzmann-Uehling-Uhlenbeck model show that the disappearance of flow is sensitive to the assumed nuclear equation of state (EOS) and to the in-medium scattering cross section ({sigma}{sub {ital N}{ital N}}). Also, in the {sup 93}Nb+{sup 93}Nb system, the purely attractive contribution to the reduced flow does not appear to be strongly sensitive to the EOS assumptions.

  12. Probing the Nuclear Spin-Lattice Relaxation Time at the Nanoscale

    NASA Astrophysics Data System (ADS)

    Wagenaar, J. J. T.; den Haan, A. M. J.; de Voogd, J. M.; Bossoni, L.; de Jong, T. A.; de Wit, M.; Bastiaans, K. M.; Thoen, D. J.; Endo, A.; Klapwijk, T. M.; Zaanen, J.; Oosterkamp, T. H.

    2016-07-01

    Nuclear spin-lattice relaxation times are measured on copper using magnetic-resonance force microscopy performed at temperatures down to 42 mK. The low temperature is verified by comparison with the Korringa relation. Measuring spin-lattice relaxation times locally at very low temperatures opens up the possibility to measure the magnetic properties of inhomogeneous electron systems realized in oxide interfaces, topological insulators, and other strongly correlated electron systems such as high-Tc superconductors.

  13. Single particle versus collectivity, shapes of exotic nuclei

    NASA Astrophysics Data System (ADS)

    Jungclaus, Andrea

    2016-03-01

    In this article some selected topics of nuclear structure research will be discussed as illustration of the progress reached in this field during the last thirty years. These examples evidence the improvement of our understanding of the atomic nucleus reached on the basis of countless experiments, performed to study both exotic nuclei (nuclei far-off the valley of stability) as well as nuclei under exotic conditions (high excitation energy/temperature or large angular momentum/rotational frequency), using stable and radioactive ion beams. The experimental progress, in parallel to the advancement of modern theoretical descriptions, led us to a much richer view of this fundamental many-body system.

  14. Excitation energy and nuclear dissipation probed with evaporation-residue cross sections

    SciTech Connect

    Ye, W.

    2011-04-15

    Using a Langevin equation coupled with a statistical decay model, we calculate the excess of evaporation-residue cross sections over its standard statistical-model value as a function of nuclear dissipation strength for {sup 200}Hg compound nuclei (CNs) under two distinct types of initial conditions for populated CNs: (i) high excitation energy but low angular momentum (produced via proton-induced spallation reactions at GeV energies and via peripheral heavy-ion collisions at relativistic energies) and (ii) high angular momentum but low excitation energy (produced through fusion mechanisms). We find that the conditions of case (ii) not only amplify the effect of dissipation on the evaporation residues, but also substantially increase the sensitivity of this excess to nuclear dissipation. These results suggest that, in experiments, to obtain accurate information of presaddle nuclear dissipation strength by measuring evaporation-residue cross sections, it is best to choose the heavy-ion-induced fusion reaction approach to yield excited compound nuclei.

  15. High homogeneity B(1) 30.2 MHz Nuclear Magnetic Resonance Probe for off-resonance relaxation times measurements.

    PubMed

    Baranowski, M; Woźniak-Braszak, A; Jurga, K

    2011-01-01

    This paper reports on design and construction of a double coil high-homogeneity ensuring Nuclear Magnetic Resonance Probe for off-resonance relaxation time measurements. NMR off-resonance experiments pose unique technical problems. Long irradiation can overheat the sample, dephase the spins because of B(1) field inhomogeneity and degrade the signal received by requiring the receiver bandwidth to be broader than that needed for normal experiment. The probe proposed solves these problems by introducing a separate off-resonance irradiation coil which is larger than the receiver coil and is wound up on the dewar tube that separates it from the receiver coil thus also thermally protects the sample from overheating. Large size of the irradiation coil also improves the field homogeneity because as a ratio of the sample diameter to the magnet (coil) diameter increases, the field inhomogeneity also increases (Blümich et al., 2008) [1]. The small receiver coil offers maximization of the filling factor and a high signal to the noise ratio.

  16. EXOTIC MAGNETS FOR ACCELERATORS.

    SciTech Connect

    WANDERER, P.

    2005-09-18

    Over the last few years, several novel magnet designs have been introduced to meet the requirements of new, high performance accelerators and beam lines. For example, the FAIR project at GSI requires superconducting magnets ramped at high rates ({approx} 4 T/s) in order to achieve the design intensity. Magnets for the RIA and FAIR projects and for the next generation of LHC interaction regions will need to withstand high doses of radiation. Helical magnets are required to maintain and control the polarization of high energy protons at RHIC. In other cases, novel magnets have been designed in response to limited budgets and space. For example, it is planned to use combined function superconducting magnets for the 50 GeV proton transport line at J-PARC to satisfy both budget and performance requirements. Novel coil winding methods have been developed for short, large aperture magnets such as those used in the insertion region upgrade at BEPC. This paper will highlight the novel features of these exotic magnets.

  17. The K{sup +} as a probe of nuclear medium effects

    SciTech Connect

    Chrien, R.E.

    1992-09-01

    The study of the K+ total cross sections on a wide range of nuclei has revealed important modifications of the free-space K+ -nucleon interaction when the nucleon is embedded in a nucleus. In addition to the previously published data on carbon and deuterium we report here the extension of such measurements to lithium, silicon, and calcium. We demonstrate that the previous reported medium modifications for carbon occur quite generally. The results are discussed as evidence for partial quark deconfinement at nuclear densities.

  18. Isospin effects on light charged particles as probes of nuclear dissipation

    SciTech Connect

    Ye, W.

    2009-07-15

    The multiplicities of postsaddle protons and {alpha} particles of the heavy systems {sup 234}Cf, {sup 240}Cf, {sup 246}Cf, and {sup 240}U as functions of the postsaddle dissipation strength are calculated in the framework of a dynamical Langevin model coupled with a statistical decay model. It is found that with increasing isospin of the Cf system, the sensitivity of the postsaddle proton and {alpha}-particle multiplicity to the dissipation strength decreases substantially, and it disappears for the {sup 240}U system. We suggest that on the experimental side, to accurately probe the postsaddle dissipation strength by measuring the prescission proton and {alpha}-particle multiplicity, it is best to populate heavy compound systems with low isospin.

  19. Physics of Exotic Nuclei at RIBF

    NASA Astrophysics Data System (ADS)

    Sakurai, Hiroyoshi

    2014-09-01

    ``Exotic nuclei'' far from the stability line are unique objects of many-body quantum system, where ratios of neutron number to proton number are much larger or much smaller than those of nuclei found in nature. Their exotic properties and phenomena emerge from their large isospin asymmetry, and even affect scenarios of nucleosynthesis in the universe. Efforts have been made to produce and investigate such exotic nuclei at the accelerator facilities in the world. One of the facilities, the Radioactive Isotope Beam Factory (RIBF) facility at RIKEN, Japan has delivered intense radioactive isotope (RI) beams since 2007. In US, the Facility for Rare Isotope Beams is being constructed to start around 2020. To access nuclei far from the stability line, especially neutron-rich nuclei, the RIBF facility is highly optimized for inflight production of fission fragments via a U beam. The Super-conducting Ring Cyclotron delivers a 345 MeV/u U beam. The U nuclide is converted at a target to fission fragments. An inflight separator BigRIPS was designed to collect about 50% of fission fragments produced at the target and separate nuclei of interest. The RI beams produced at BigRIPS are then delivered to several experimental devices. Large-scale international collaborations have been formed at three spectrometers to conduct unique programs for the investigation of decay properties single particle orbits, collective motions, nucleon correlation, and the equation-of-state of asymmetric nuclear matter. Nuclear binding energy will be measured at a newly constructed ring for the r-process path, and charge distribution of exotic nuclei will be examined at a unique setup of an RI target section in an electron storage ring. Ultra slow RI beams available at a gas catcher system will be utilized for table-top and high precision measurements. In this talk, I would give a facility overview of RIBF, and introduce objectives at RIBF. Special emphasis would be given to selected recent highlights

  20. Role of nuclear analytical probe techniques in biological trace element research

    SciTech Connect

    Jones, K.W.; Pounds, J.G.

    1985-01-01

    Many biomedical experiments require the qualitative and quantitative localization of trace elements with high sensitivity and good spatial resolution. The feasibility of measuring the chemical form of the elements, the time course of trace elements metabolism, and of conducting experiments in living biological systems are also important requirements for biological trace element research. Nuclear analytical techniques that employ ion or photon beams have grown in importance in the past decade and have led to several new experimental approaches. Some of the important features of these methods are reviewed here along with their role in trace element research, and examples of their use are given to illustrate potential for new research directions. It is emphasized that the effective application of these methods necessitates a closely integrated multidisciplinary scientific team. 21 refs., 4 figs., 1 tab.

  1. Probing nuclear dynamics and architecture using single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Jung, Yoon; Li, Junang; Fakhri, Nikta

    Chromatin is a multiscale dynamic architecture that acts as a template for many biochemical processes such as transcription and DNA replication. Recent developments such as Hi-C technology enable an identification of chromatin interactions across an entire genome. However, a single cell dynamic view of chromatin organization is far from understood. We discuss a new live cell imaging technique to probe the dynamics of the nucleus at a single cell level using single-walled carbon nanotubes (SWNTs). SWNTs are non-perturbing rigid rods (diameter of 1 nm and length of roughly 100 nm) that fluoresce in the near infrared region. Due to their high aspect ratio, they can diffuse in tight spaces and report on the architecture and dynamics of the nucleoplasm. We develop 3D imaging and tracking of SWNTs in the volume of the nucleus using double helix point spread function microscopy (DH-PSF) and discuss the capabilities of the DH-PSF for inferring the 3D orientation of nanotubes based on vectorial diffraction theory.

  2. Fourteenth Exotic Beam Summer School EBSS 2015

    SciTech Connect

    Wiedenhoever, Ingo

    2016-07-11

    The Fourteenth Annual Exotic Beam Summer School EBSS 2015 was held August 2nd - August 7th, 2015, and belongs to the series of summer programs aimed at educating future workforce in nuclear physics-related areas, mostly about the challenges of radioactive ion beam physics. Through these schools the research community will be able to exploit fully the opportunities created by the exotic beam facilities. These facilities in the US include CARIBU at ANL, the NSCL and the future FRIB laboratory as well as smaller-scale university laboratories. The skill set needed by the future workforce is very diverse and a fundamental understanding of theoretical, technical, computational and applied fields are all important. Therefore, the Exotic Beam Summer Schools follow a unique approach, in which the students not only receive lectures but also participate in hands-on activities. The lectures covered broad topics in both the experimental and theoretical physics of nuclei far from stability as well as radioactive ions production and applications. The afternoons provided opportunities for "hands-on" projects with experimental equipment and techniques useful in FRIB research. Five activities were performed in groups of eight students, rotating through the activities over the five afternoons of the school. The center of the activities was an experiment at the FSU tandem accelerator, measuring the angular distribution and cross section of the 12C(d,p)13C transfer reaction, measured with a silicon telescope in a scattering chamber. The experimental data were analyzed by performing a DWBA calculation with the program DWUCK, and the resulting spectroscopic factors were compared to a shell model calculation. The other activities included target preparation, digital gamma-spectroscopy and modern neutron detection methods.

  3. Using fluorine nuclear magnetic resonance to probe the interaction of membrane-active peptides with the lipid bilayer.

    PubMed

    Buer, Benjamin C; Chugh, Jeetender; Al-Hashimi, Hashim M; Marsh, E Neil G

    2010-07-13

    A variety of biologically active peptides exert their function through direct interactions with the lipid membrane of the cell. These surface interactions are generally transient and highly dynamic, making them hard to study. Here we have examined the feasibility of using solution phase (19)F nuclear magnetic resonance (NMR) to study peptide-membrane interactions. Using the antimicrobial peptide MSI-78 as a model system, we demonstrate that peptide binding to either small unilamellar vesicles (SUVs) or bicelles can readily be detected by simple one-dimensional (19)F NMR experiments with peptides labeled with l-4,4,4-trifluoroethylglycine. The (19)F chemical shift associated with the peptide-membrane complex is sensitive both to the position of the trifluoromethyl reporter group (whether in the hydrophobic face or positively charged face of the amphipathic peptide) and to the curvature of the lipid bilayer (whether the peptide is bound to SUVs or bicelles). (19)F spin echo experiments using the Carr-Purcell-Meiboom-Gill pulse sequence were used to measure the transverse relaxation (T(2)) of the nucleus and thereby examine the local mobility of the MSI-78 analogues bound to bicelles. The fluorine probe positioned in the hydrophobic face of the peptide relaxes at a rate that correlates with the tumbling of the bicelle, suggesting that it is relatively immobile, whereas the probe at the positively charged face relaxes more slowly, indicating this position is much more dynamic. These results are in accord with structural models of MSI-78 bound to lipids and point to the feasibility of using fluorine-labeled peptides to monitor peptide-membrane interactions in living cells.

  4. Multiparticle Correlation Functions: A probe for the High Energy Density Nuclear Matter created at RHIC

    NASA Astrophysics Data System (ADS)

    Holzmann, Wolf

    2002-04-01

    In a recent publication [1], the PHENIX collaboration has reported on the transverse momentum spectra for charged hadrons and for neutral pions in the range 1 < pT < 5 GeV/c. The spectra from peripheral nuclear collisions were found to be consistent with a simple scaling of the spectra from p+p collisions by the average number of nucleon-nucleon binary collisions. In contrast, the spectra from central collisions appeared to be significantly suppressed when compared to that from peripheral collisions as well as to the scaled p+p expectation. These observations have been interpreted as an important signature for jet quenching( [1],[2]) in central Au + Au collisions at RHIC. Significant jet production should also lead to discernable multi-particle correlations. Thus, the study of such correlations and their possible modification due to quenching, offers a promising opportunity for the investigation and study of QGP formation at RHIC. The multiparticle correlation analysis technique will be presented in conjunction with possible results for Au + Au data (sqrt(s) = 200GeV/c) obtained with the PHENIX detector at RHIC [1] Adcox et al., Phys. Rev. Lett. 88, 022301 (2001) [2] M. Gyulassy and X.-N. Wang, Nucl. Phys. B420, 583 (1994)X.-N. Wang, M.Gyulassy and M. Pluemer, Phys. Rev. D 51, 3436 (1995)

  5. Probing the folding intermediate of Bacillus subtilis RNase P protein by nuclear magnetic resonance.

    PubMed

    Chang, Yu-Chu; Franch, William R; Oas, Terrence G

    2010-11-09

    Protein folding intermediates are often imperative for overall folding processes and consequent biological functions. However, the low population and transient nature of the intermediate states often hinder their biochemical and biophysical characterization. Previous studies have demonstrated that Bacillus subtilis ribonuclease P protein (P protein) is conformationally heterogeneous and folds with multiphasic kinetics, indicating the presence of an equilibrium and kinetic intermediate in its folding mechanism. In this study, nuclear magnetic resonance (NMR) spectroscopy was used to study the ensemble corresponding to this intermediate (I). The results indicate that the N-terminal and C-terminal helical regions are mostly unfolded in I. 1H−15N heteronuclear single-quantum coherence NMR spectra collected as a function of pH suggest that the protonation of His 22 may play a major role in the energetics of the equilibria among the unfolded, intermediate, and folded state ensembles of P protein. NMR paramagnetic relaxation enhancement experiments were also used to locate the small anion binding sites in both the intermediate and folded ensembles. The results for the folded protein are consistent with the previously modeled binding regions. These structural insights suggest a possible role for I in the RNase P holoenzyme assembly process.

  6. Investigations of ion-irradiated uranium dioxide nuclear fuel with laser-assisted atom probe tomography

    NASA Astrophysics Data System (ADS)

    Valderrama, Billy

    Performance in commercial light water reactors is dictated by the ability of its fuel material, uranium dioxide (UO2), to transport heat generated during the fission process. It is widely known that the service lifetime is limited by irradiation-induced microstructural changes that degrade the thermal performance of UO2. Studying the role of complex, often interacting mechanisms that occur during the early stages of microstructural evolution presents a challenge. Phenomena of particular interest are the segregation of fission products to form bubbles and their resultant effect on grain boundary (GB) mobility, and the effect of irradiation on fuel stoichiometry. Each mechanism has a profound consequence on fuel thermal conductivity. Several advanced analytical techniques, such as transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, etc. have been used to study these mechanisms. However, they each have limitations and cannot individually provide the necessary information for deeper understanding. One technique that has been under utilized is atom probe tomography (APT), which has a unique ability to spatially resolve small-scale chemical variations. APT uses the principle of field ionization to evaporate surface ions for chemical analysis. For low electrical conductivity systems, a pulsed laser is used to thermally assist in the evaporation process. One factor complicating the analysis is that laser-material interactions are poorly understood for oxide materials and literature using this technique with UO2 is lacking. Therefore, an initial systematic study to identify the optimal conditions for the analysis of UO2 using laser-assisted APT was conducted. A comparative study on the evaporation behavior between CeO2 and UO2 was followed. CeO2 was chosen due to its technological relevancy and availability of comparative studies with laser-assisted APT. Dissimilar evaporation behavior between these materials was identified and attributed

  7. Associated-particle sealed-tube neutron probe: Detection of explosives, contraband, and nuclear materials

    SciTech Connect

    Rhodes, E.; Dickerman, C.E.

    1996-05-01

    Continued research and development of the APSTNG shows the potential for practical field use of this technology for detection of explosives, contraband, and nuclear materials. The APSTNG (associated-particle sealed-tube generator) inspects the item to be examined using penetrating 14-MeV neutrons generated by the deuterium-tritium reaction inside a compact accelerator tube. An alpha detector built into the sealed tube detects the alpha-particle associated with each neutron emitted in a cone encompassing the volume to be inspected. Penetrating high-energy gamma-rays from the resulting neutron reactions identify specific nuclides inside the volume. Flight-times determined from the detection times of gamma-rays and alpha-particles separate the prompt and delayed gamma-ray spectra and allow a coarse 3-D image to be obtained of nuclides identified in the prompt spectrum. The generator and detectors can be on the same side of the inspected object, on opposite sides, or with intermediate orientations. Thus, spaces behind walls and other confined regions can be inspected. Signals from container walls can be discriminated against using the flight-time technique. No collimators or shielding are required, the neutron generator is relatively small, and commercial-grade electronics are employed. The use of 14-MeV neutrons yields a much higher cross-section for detecting nitrogen than that for systems based on thermal-neutron reactions alone, and the broad range of elements with significant 14-MeV neutron cross-sections extends explosives detection to other elements including low-nitrogen compounds, and allows detection of many other substances. Proof-of-concept experiments have been successfully performed for conventional explosives, chemical warfare agents, cocaine, and fissionable materials.

  8. Proceedings of the international conference on nuclear physics, August 24-30, 1980, Berkeley, California. Volume 1. Abstracts. [Berkeley, California, August 24-30, 1980 (abstracts only)

    SciTech Connect

    Not Available

    1980-01-01

    This volume contains all abstracts (931) received by the conference organizers before June 20, 1980. The abstracts are grouped according to the following topics: nucleon-nucleon interactions, free and in nuclei; distribution of matter, charge, and magnetism; exotic nuclei and exotic probes; giant resonances and other high-lying excitations; applications of nuclear science; nuclei with large angular momentum and deformation; heavy-ion reactions and relaxation phenomena; new techniques and instruments; pion absorption and scattering by nuclei; and miscellaneous. Some of these one-page abstracts contain data. A complete author index is provided. (RWR)

  9. Exotic nuclei in astrophysics

    NASA Astrophysics Data System (ADS)

    Penionzhkevich, Yu. E.

    2012-07-01

    Recently the academic community has marked several anniversaries connected with discoveries that played a significant role in the development of astrophysical investigations. The year 2009 was proclaimed by the United Nations the International Year of Astronomy. This was associated with the 400th anniversary of Galileo Galilei's discovery of the optical telescope, which marked the beginning of regular research in the field of astronomy. An important contribution to not only the development of physics of the microcosm, but also to the understanding of processes occurring in the Universe, was the discovery of the atomic nucleus made by E. Rutherford 100 years ago. Since then the investigations in the fields of physics of particles and atomic nuclei have helped to understand many processes in the microcosm. Exactly 80 years ago, K. Yanski used a radio-telescope in order to receive the radiation from cosmic objects for the first time, and at the present time this research area of physics is the most efficient method for studying the properties of the Universe. Finally, the April 12, 1961 (50 years ago) launching of the first sputnik into space with a human being onboard, the Russian cosmonaut Yuri Gagarin, marked the beginning of exploration of the Universe with the direct participation of man. All these achievements considerably extended our ideas about the Universe. This work is an attempt to present some problems on the evolution of the Universe: the nucleosynthesis and cosmochronology from the standpoint of physics of particles and nuclei, in particular with the use of the latest results, obtained by means of radioactive nuclear beams. The comparison is made between the processes taking place in the Universe and the mechanisms of formation and decay of nuclei, as well as of their interaction at different energies. Examples are given to show the capabilities of nuclear-physics methods for studying cosmic objects and properties of the Universe. The results of

  10. Micro-fluidics and integrated optics glass sensor for in-line micro-probing of nuclear samples

    SciTech Connect

    Schimpf, A.; Canto, F.; Bucci, D.; Magnaldo, A.; Couston, L.; Broquin, J. E.

    2011-07-01

    We study the miniaturisation of Thermal Lens Spectrometry (TLS) towards Lab-on-chip integration in order to reduce the volume of fluid assays in nuclear process control. TLS is of great interest in this context since it combines the advantages of optical detection methods with an inherent suitability for small-scale samples. After validating the experimental principle in a classical thermal lens crossed-beam setup, we show the integration of a Young-interferometer with a microcapillary on a glass substrate, reducing the necessary sample size to 400 nl. The interferometer translates the photo-thermally induced refractive index change in the fluid to a phase shift of the fringe pattern, which can then be detected by a camera. Measurements of Co(II) in ethanol yield a detection limit of c = 5 x 10{sup -4} M for the crossed-beam setup and c = 6x10{sup -3} M for the integrated sensor. At an interaction length of 10 {mu}m, it detects a minimum absorbance of AU = 6 x 10{sup -5} in a probed volume of 10 pl. (authors)

  11. Micro-fluidics and integrated optics glass sensor for in-line micro-probing of nuclear samples

    SciTech Connect

    Schimpf, A.; Bucci, D.; Broquin, J.E.; Canto, F.; Magnaldo, A.; Couston, L.

    2012-08-15

    We study the miniaturization of Thermal Lens Spectrometry (TLS) towards Lab-on-chip integration in order to reduce the volume of fluid assays in nuclear process control. TLS is of great interest in this context since it combines the advantages of optical detection methods with an inherent suitability for small-scale samples. After validating the experimental principle in a classical thermal lens crossed-beam setup, we show the integration of a Young-interferometer with a microcapillary on a glass substrate, reducing the necessary sample size to 400 nl. The interferometer translates the photo-thermally induced refractive index change in the fluid to a phase shift of the fringe pattern, which can then be detected by a camera. Measurements of Co(II) in ethanol yield a detection limit of c = 5 x 10{sup -4} M for the crossed-beam setup and c = 6 x 10{sup -3} M for the integrated sensor. At an interaction length of 10 m, it detects a minimum absorbance of K = 1.2 x 10{sup -4} in a probed volume of 14 pl. (authors)

  12. A new combined nuclear magnetic resonance and Raman spectroscopic probe applied to in situ investigations of catalysts and catalytic processes

    NASA Astrophysics Data System (ADS)

    Camp, Jules C. J.; Mantle, Michael D.; York, Andrew P. E.; McGregor, James

    2014-06-01

    Both Raman and nuclear magnetic resonance (NMR) spectroscopies are valuable analytical techniques capable of providing mechanistic information and thereby providing insights into chemical processes, including catalytic reactions. Since both techniques are chemically sensitive, they yield not only structural information but also quantitative analysis. In this work, for the first time, the combination of the two techniques in a single experimental apparatus is reported. This entailed the design of a new experimental probe capable of recording simultaneous measurements on the same sample and/or system of interest. The individual datasets acquired by each spectroscopic method are compared to their unmodified, stand-alone equivalents on a single sample as a means to benchmark this novel piece of equipment. The application towards monitoring reaction progress is demonstrated through the evolution of the homogeneous catalysed metathesis of 1-hexene, with both experimental techniques able to detect reactant consumption and product evolution. This is extended by inclusion of magic angle spinning (MAS) NMR capabilities with a custom made MAS 7 mm rotor capable of spinning speeds up to 1600 Hz, quantified by analysis of the spinning sidebands of a sample of KBr. The value of this is demonstrated through an application involving heterogeneous catalysis, namely the metathesis of 2-pentene and ethene. This provides the added benefit of being able to monitor both the reaction progress (by NMR spectroscopy) and also the structure of the catalyst (by Raman spectroscopy) on the very same sample, facilitating the development of structure-performance relationships.

  13. Multi-MICE: Nuclear Powered Mobile Probes to Explore Deep Interiors of the Ice Sheets on Mars and the Jovian Moons

    SciTech Connect

    Maise, George; Powell, James; Paniagua, John; Powell, Jesse; Ludewig, Hans

    2007-01-30

    The multi-kilometer thick Polar Caps on Mars contain unique and important data about the multi-million year history of its climate, geology, meteorology, volcanology, cosmic ray and solar activity, and meteor impacts. They also may hold evidence of past life on Mars, including microbes, microfossils and biological chemicals. The objective of this paper is to describe a probe that can provide access to the data locked in the Polar Caps. The MICE (Mars Ice Cap Explorer) system would explore the Polar Cap interiors using mobile probes powered by compact, lightweight nuclear reactors. The probes would travel 100's of meters per day along melt channels in the ice sheets created by hot water jets from the 500 kW(th) nuclear reactors, ascending and descending, either vertically or at an angle to the vertical, reaching bedrock at kilometers beneath the surface. The powerful reactor will be necessary to provide sufficient hot water at high velocity to penetrate the extensive horizontal dust/sand layers that separate layers of ice in the Mars Ice Caps. MICE reactors can operate at 500 kW(th) for more than 4 years, and much longer in practice, since power level will be much lower when the probes are investigating locations in detail at low or zero speed. Multiple probes, e.g. six, would be deployed in an interactive network, continuously communicating by RF and acoustic signals with each other and with the surface lander spacecraft. In turn, the lander would continuously communicate in real time, subject to speed of light delays, with scientists on Earth to transmit data and receive instructions for the MICE probes. Samples collected by the probes could be brought to the lander, for return to the Earth at the end of the mission.

  14. Multi-MICE: Nuclear Powered Mobile Probes to Explore Deep Interiors of the Ice Sheets on Mars and the Jovian Moons

    NASA Astrophysics Data System (ADS)

    Maise, George; Powell, James; Powell, Jesse; Paniagua, John; Ludewig, Hans

    2007-01-01

    The multi-kilometer thick Polar Caps on Mars contain unique and important data about the multi-million year history of its climate, geology, meteorology, volcanology, cosmic ray and solar activity, and meteor impacts. They also may hold evidence of past life on Mars, including microbes, microfossils and biological chemicals. The objective of this paper is to describe a probe that can provide access to the data locked in the Polar Caps. The MICE (Mars Ice Cap Explorer) system would explore the Polar Cap interiors using mobile probes powered by compact, lightweight nuclear reactors. The probes would travel 100's of meters per day along melt channels in the ice sheets created by hot water jets from the 500 kW(th) nuclear reactors, ascending and descending, either vertically or at an angle to the vertical, reaching bedrock at kilometers beneath the surface. The powerful reactor will be necessary to provide sufficient hot water at high velocity to penetrate the extensive horizontal dust/sand layers that separate layers of ice in the Mars Ice Caps. MICE reactors can operate at 500 kW(th) for more than 4 years, and much longer in practice, since power level will be much lower when the probes are investigating locations in detail at low or zero speed. Multiple probes, e.g. six, would be deployed in an interactive network, continuously communicating by RF and acoustic signals with each other and with the surface lander spacecraft. In turn, the lander would continuously communicate in real time, subject to speed of light delays, with scientists on Earth to transmit data and receive instructions for the MICE probes. Samples collected by the probes could be brought to the lander, for return to the Earth at the end of the mission.

  15. Perspectives of Physics of Exotic Nuclei Beyond the Shell Evolution

    NASA Astrophysics Data System (ADS)

    Otsuka, Takaharu

    2015-11-01

    I present one of the possible paradigm shifts with exotic nuclei. This is the shell evolution due to nuclear forces, such as tensor, central and three-nucleon forces. I shall present major points with the N=34 magic number confirmed in 54Ca by RIBF of RIKEN very recently, after the theoretical prediction made in 2001. The shell evolution has been generalized to phenomena caused by massive particle-hole excitations, being referred to as Type II Shell Evolution. This can be found in 68,70Ni. In particular, the shape coexistence of spherical, oblate and prolate shapes is suggested theoretically. Thus, the perspectives of physics with exotic nuclei is being expanded further from single-particle aspects to shapes/deformation, changing the landscape of nuclear structure.

  16. Exotic aphid control with pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exotic aphids are invading ecosystems worldwide. The principal factors favoring establishment of these pests are their small size, parthenogenetic reproduction, short generation time, ability for long distance dispersal as winged morphs, and explosive population dynamics. In the past, attention to i...

  17. Electronic pairing in exotic superconductors

    SciTech Connect

    Cox, D.L. ); Maple, M.B. )

    1995-02-01

    Superconductivity in heavy-fermion materials and high T[sub c] cuprates may involve electronic pairing with unconventional symmetries and mechanisms. Although there has been no smoking-gun proof, numerous pieces of circumstantial evidence combined with heuristic theoretical arguments make a compelling case that these materials have pairs with exotic symmetry bound by nonphonon glue. 20 refs., 5 figs.

  18. Application of capillary electrophoresis with laser-induced fluorescence detection for the determination of trace neodymium in spent nuclear fuel using complexation with an emissive macrocyclic polyaminocarboxylate probe.

    PubMed

    Haraga, Tomoko; Saito, Shingo; Sato, Yoshiyuki; Asai, Shiho; Hanzawa, Yukiko; Hoshino, Hitoshi; Shibukawa, Masami; Ishimori, Ken-ichiro; Takahashi, Kuniaki

    2014-01-01

    A simple and rapid method with low radiation exposure risk was developed for the determination of neodymium in spent nuclear fuel by capillary electrophoresis with laser-induced fluorescence detection using a fluorescent probe having a macrocyclic hexadentate polyaminocarboxylate structure. The concentration of Nd(III) in a spent nuclear fuel sample was determined with no interference from various matrix elements, including lanthanides and uranium (at a 200-fold excess), with 92 ± 3% recovery. This is due to high resolution based on establishing a ternary complex equilibrium during migration in which the hydroxyl ion plays an auxiliary role (log K(Ln-L-OH) = 3.9-5.3).

  19. AttoPhotoChemistry. Probing ultrafast electron dynamics by the induced nuclear motion: The prompt and delayed predissociation of N2

    NASA Astrophysics Data System (ADS)

    Muskatel, B. H.; Remacle, F.; Levine, R. D.

    2014-05-01

    Quantum mechanical wavepacket dynamics simulation that includes the nuclear motion exhibit a prompt, few fs, dissociation of electronically attosecond excited N2 in addition to the slow dissociation evident from spectral line broadening in well resolved spectra. The simulations show that nuclear motion can probe early times electron dynamics. The separation of time scales is mimicked by a model study fashioned like chemical kinetics of unimolecular dissociation. The physical origin of the separation into prompt and delayed decay is argued to be the same in the vibrational and the present case, namely that there are more bound than dissociative channels.

  20. Nuclear 111Cd probes detect a hidden symmetry change at the γ → α transition in cerium considered isostructural for 60 years

    NASA Astrophysics Data System (ADS)

    Tsvyashchenko, A. V.; Nikolaev, A. V.; Velichkov, A. I.; Salamatin, A. V.; Fomicheva, L. N.; Ryasny, G. K.; Sorokin, A. A.; Kochetov, O. I.; Budzynski, M.

    2010-10-01

    We use the time-differential perturbed angular correlation technique to study nuclear electric quadupole hyperfine interactions of probe 111Cd nuclei in cerium lattice sites at room temperature under pressures up to 8 GPa. We have found that the well known γ → α phase transition in cerium is not isostructural. In α-Ce, the probe 111Cd nuclei reveal a quadrupole electron charge density component that is absent in γ-Ce. The hidden spacial structure of electronic quadrupoles in α-Ce is triple-q antiferroquadrupolar, as was suggested in [14]. We relate our findings to the current understanding of the γ → α phase transition and also report on nuclear quadrupole interactions in other high-pressure phases of cerium: α″ ( C2/ m space symmetry) and α' (α-U structure).

  1. Nuclear {sup 111}Cd probes detect a hidden symmetry change at the {gamma} {sup {yields} {alpha}} transition in cerium considered isostructural for 60 years

    SciTech Connect

    Tsvyashchenko, A. V.; Nikolaev, A. V.; Velichkov, A. I.; Salamatin, A. V.; Fomicheva, L. N.; Ryasny, G. K.; Sorokin, A. A.; Kochetov, O. I.; Budzynski, M.

    2010-10-15

    We use the time-differential perturbed angular correlation technique to study nuclear electric quadrupole hyperfine interactions of probe {sup 111}Cd nuclei in cerium lattice sites at room temperature under pressures up to 8 GPa. We have found that the well known {gamma} {sup {yields} {alpha}} phase transition in cerium is not isostructural. In {alpha}-Ce, the probe {sup 111}Cd nuclei reveal a quadrupole electron charge density component that is absent in {gamma}-Ce. The hidden spacial structure of electronic quadrupoles in {alpha}-Ce is triple-q antiferroquadrupolar, as was suggested in [14]. We relate our findings to the current understanding of the {gamma} {sup {yields} {alpha}} phase transition and also report on nuclear quadrupole interactions in other high-pressure phases of cerium: {alpha}'' (C2/m space symmetry) and {alpha}' ({alpha}-U structure).

  2. Search for exotic short-range interactions using paramagnetic insulators

    DOE PAGES

    Chu, Pinghan; Weisman, E.; Liu, C. -Y.; ...

    2015-05-26

    We describe a proposed experimental search for exotic spin-coupled interactions using a solid-state paramagnetic insulator. The experiment is sensitive to the net magnetization induced by the exotic interaction between the unpaired insulator electrons with a dense, nonmagnetic mass in close proximity. An existing experiment has been used to set limits on the electric dipole moment of the electron by probing the magnetization induced in a cryogenic gadolinium gallium garnet sample on application of a strong electric field. With suitable additions, including a movable source mass, this experiment can be used to explore “monopole-dipole” forces on polarized electrons with unique ormore » unprecedented sensitivity. As a result, the solid-state, nonmagnetic construction, combined with the low-noise conditions and extremely sensitive magnetometry available at cryogenic temperatures could lead to a sensitivity over 10 orders of magnitude greater than exiting limits in the range below 1 mm.« less

  3. Search for exotic short-range interactions using paramagnetic insulators

    SciTech Connect

    Chu, Pinghan; Weisman, E.; Liu, C. -Y.; Long, J. C.

    2015-05-26

    We describe a proposed experimental search for exotic spin-coupled interactions using a solid-state paramagnetic insulator. The experiment is sensitive to the net magnetization induced by the exotic interaction between the unpaired insulator electrons with a dense, nonmagnetic mass in close proximity. An existing experiment has been used to set limits on the electric dipole moment of the electron by probing the magnetization induced in a cryogenic gadolinium gallium garnet sample on application of a strong electric field. With suitable additions, including a movable source mass, this experiment can be used to explore “monopole-dipole” forces on polarized electrons with unique or unprecedented sensitivity. As a result, the solid-state, nonmagnetic construction, combined with the low-noise conditions and extremely sensitive magnetometry available at cryogenic temperatures could lead to a sensitivity over 10 orders of magnitude greater than exiting limits in the range below 1 mm.

  4. Triton-{sup 3}He relative and differential flows as probes of the nuclear symmetry energy at supra-saturation densities

    SciTech Connect

    Yong Gaochan; Li Baoan; Chen Liewen; Zhang Xunchao

    2009-10-15

    Using a transport model coupled with a phase-space coalescence afterburner, we study the triton-{sup 3}He (t-{sup 3}He) ratio with both relative and differential transverse flows in semicentral {sup 132}Sn+{sup 124}Sn reactions at a beam energy of 400 MeV/nucleon. The neutron-proton ratios with relative and differential flows are also discussed as a reference. We find that similar to the neutron-proton pairs, the t-{sup 3}He pairs also carry interesting information regarding the density dependence of the nuclear symmetry energy. Moreover, the nuclear symmetry energy affects more strongly the t-{sup 3}He relative and differential flows than the {pi}{sup -}/{pi}{sup +} ratio in the same reaction. The t-{sup 3}He relative flow can be used as a particularly powerful probe of the high-density behavior of the nuclear symmetry energy.

  5. The charge breeder beam line for the selective production of exotic species project at INFN-Legnaro National Laboratories

    NASA Astrophysics Data System (ADS)

    Galatà, A.; Comunian, M.; Maggiore, M.; Manzolaro, M.; Angot, J.; Lamy, T.

    2014-02-01

    SPES (Selective Production of Exotic Species) is an INFN (Istituto Nazionale di Fisica Nucleare) project with the aim at producing and post-accelerating exotic beams to perform forefront research in nuclear physics. To allow post-acceleration of the radioactive ions, an ECR-based Charge Breeder (CB) developed on the basis of the Phoenix booster was chosen. The design of the complete beam line for the SPES-CB will be described: a system for stable 1+ beams production was included; special attention was paid to the medium resolution mass spectrometer after the CB to limit possible superposition of the exotic beams with the impurities present in the ECR plasma.

  6. Why own an exotic pet?

    PubMed

    Moutou, F; Pastoret, P P

    2010-08-01

    Even though people have owned a wide variety of companion animals since times of old, the modern craze for increasingly exotic and little-known species raises a number of questions, including some of an ethical nature. While trade in exotic animals is certainly profitable for these who practise it, it poses great risks of varying types: ecological risks, threats to biodiversity conservation and health risks. Several introduced animal populations have gone on to establish a line in their new host country. We are just starting to measure the adverse impact this has had, in some cases on a very large scale. The veterinary profession doubtless has a major role to play in endeavouring to reform this trade in living creatures that unfortunately results in many losses.

  7. Nitrogen nuclear spin flips in nitroxide spin probes of different sizes in glassy o-terphenyl: Possible relation with α- and β-relaxations

    NASA Astrophysics Data System (ADS)

    Isaev, N. P.; Dzuba, S. A.

    2011-09-01

    The pulsed electron-electron double resonance (ELDOR) technique was employed to study nitroxide spin probes of three different sizes dissolved in glassy o-terphenyl. A microwave pulse applied to the central hyperfine structure (hfs) component of the nitroxide electron paramagnetic resonance spectrum was followed by two echo-detecting pulses of different microwave frequency to probe the magnetization transfer (MT) to the low-field hfs component. The MT between hfs components is readily related to flips in the nitrogen nuclear spin, which in turn are induced by molecular motion. The MT on the time scale of tens of microseconds was observed over a wide temperature range, including temperatures near and well below the glass transition. For a bulky nitroxide, it was found that MT rates approach dielectric α (primary) relaxation frequencies reported for o-terphenyl in the literature. For small nitroxides, MT rates were found to match the frequencies of dielectric β (secondary) Johari-Goldstein relaxation. The most probable motional mechanism inducing the nitrogen nuclear spin flips is large-angle angular jumps, between some orientations of unequal occupation probabilities. The pulsed ELDOR of nitroxide spin probes may provide additional insight into the nature of Johari-Goldstein relaxation in glassy media and may serve as a tool for studying this relaxation in substances consisting of non-rigid molecules (such as branched polymers) and in heterogeneous and non-polar systems (such as a core of biological membranes).

  8. TOF Mass Measurements of Very Exotic Nuclides: an Input for Astrophysical Calculations

    NASA Astrophysics Data System (ADS)

    Matoš, M.; Estrade, A.; Amthor, M.; Bazin, D.; Becerril, A.; Elliot, T.; Galaviz, D.; Gade, A.; Lorusso, G.; Montes, F.; Pereira, J.; Portillo, M.; Rogers, A. M.; Schatz, H.; Stolz, A.; Aprahamian, A.; Shapira, D.; Smith, E.; Gupta, S.; Wallace, M.

    2007-10-01

    Atomic masses play a crucial role in many nuclear astrophysics calculations. Very exotic nuclei can be accessed by time-of- flight techniques at radioactive beam facilities. The NSCL facility provides a well-suited infrastructure for TOF mass measurements of very exotic nuclei. At this facility, we have recently implemented a TOF-Bρ technique and performed mass measurements of neutron-rich nuclides in the Fe region, important for calculations of the r-process and processes occurring in the crust of accreting neutron stars. Description of the TOF technique, results and future plans related to nuclear astrophysics will be presented.

  9. (13)C-labeled biochemical probes for the study of cancer metabolism with dynamic nuclear polarization-enhanced magnetic resonance imaging.

    PubMed

    Salamanca-Cardona, Lucia; Keshari, Kayvan R

    2015-01-01

    In recent years, advances in metabolic imaging have become dependable tools for the diagnosis and treatment assessment in cancer. Dynamic nuclear polarization (DNP) has recently emerged as a promising technology in hyperpolarized (HP) magnetic resonance imaging (MRI) and has reached clinical relevance with the successful visualization of [1-(13)C] pyruvate as a molecular imaging probe in human prostate cancer. This review focuses on introducing representative compounds relevant to metabolism that are characteristic of cancer tissue: aerobic glycolysis and pyruvate metabolism, glutamine addiction and glutamine/glutamate metabolism, and the redox state and ascorbate/dehydroascorbate metabolism. In addition, a brief introduction of probes that can be used to trace necrosis, pH changes, and other pathways relevant to cancer is presented to demonstrate the potential that HP MRI has to revolutionize the use of molecular imaging for diagnosis and assessment of treatments in cancer.

  10. Zoonotic parasites from exotic meat in Malaysia.

    PubMed

    Fazly, Z A; Nurulaini, R; Shafarin, M S; Fariza, N J; Zawida, Z; Muhamad, H Y; Adnan, M; Premaalatha, B; Erwanas, A I; Zaini, C M; Ong, C C; Chandrawathani, P

    2013-09-01

    Four zoonotic parasites, Sarcocystis spp., Toxoplasma gondii, Trichinella spp. and Taenia spp were screened in exotic meats. A total of forty-six (n=46) meat samples from various species of exotic animals were received from all the 14 states in Malaysia from January 2012 to April 2012. All exotic meat samples were examined macroscopically and histologically for the four zoonotic parasites. Results by histological examination of exotic meats showed the presence of Sarcocystis and Toxoplasma cysts at 8.7% (n=4) and 4.3% (n=2) respectively. No Trichinella spp. and Taenia spp. were found.

  11. Young and Exotic Stellar Zoo

    NASA Astrophysics Data System (ADS)

    2005-03-01

    Summary Super star clusters are groups of hundreds of thousands of very young stars packed into an unbelievably small volume. They represent the most extreme environments in which stars and planets can form. Until now, super star clusters were only known to exist very far away, mostly in pairs or groups of interacting galaxies. Now, however, a team of European astronomers [1] have used ESO's telescopes to uncover such a monster object within our own Galaxy, the Milky Way, almost, but not quite, in our own backyard! The newly found massive structure is hidden behind a large cloud of dust and gas and this is why it took so long to unveil its true nature. It is known as "Westerlund 1" and is a thousand times closer than any other super star cluster known so far. It is close enough that astronomers may now probe its structure in some detail. Westerlund 1 contains hundreds of very massive stars, some shining with a brilliance of almost one million suns and some two-thousand times larger than the Sun (as large as the orbit of Saturn)! Indeed, if the Sun were located at the heart of this remarkable cluster, our sky would be full of hundreds of stars as bright as the full Moon. Westerlund 1 is a most unique natural laboratory for the study of extreme stellar physics, helping astronomers to find out how the most massive stars in our Galaxy live and die. From their observations, the astronomers conclude that this extreme cluster most probably contains no less than 100,000 times the mass of the Sun, and all of its stars are located within a region less than 6 light-years across. Westerlund 1 thus appears to be the most massive compact young cluster yet identified in the Milky Way Galaxy. PR Photo 09a/05: The Super Star Cluster Westerlund 1 (2.2m MPG/ESO + WFI) PR Photo 09b/05: Properties of Young Massive Clusters Super Star Clusters Stars are generally born in small groups, mostly in so-called "open clusters" that typically contain a few hundred stars. From a wide range of

  12. Anatomy of exotic Higgs decays in 2HDM

    DOE PAGES

    Kling, Felix; No, Jose Miguel; Su, Shufang

    2016-09-16

    Large mass splittings between new scalars in two-Higgs-doublet models (2HDM) open a key avenue to search for these new states via exotic heavy Higgs decays. We discuss in detail the different search channels for these new scalars at the LHC in the presence of a sizable mass splitting, i.e. a hierarchical 2HDM scenario, taking into account the theoretical and experimental constraints. Here, we provide benchmark planes to exploit the complementarity among these searches, analyzing their potential to probe the hierarchical 2HDM parameter space during LHC Run 2.

  13. Anatomy of exotic Higgs decays in 2HDM

    NASA Astrophysics Data System (ADS)

    Kling, Felix; No, Jose Miguel; Su, Shufang

    2016-09-01

    Large mass splittings between new scalars in two-Higgs-doublet models (2HDM) open a key avenue to search for these new states via exotic heavy Higgs decays. We discuss in detail the different search channels for these new scalars at the LHC in the presence of a sizable mass splitting, i.e. a hierarchical 2HDM scenario, taking into account the theoretical and experimental constraints. We provide benchmark planes to exploit the complementarity among these searches, analyzing their potential to probe the hierarchical 2HDM parameter space during LHC Run 2.

  14. Ectoparasites in small exotic mammals.

    PubMed

    Fehr, Michael; Koestlinger, Saskia

    2013-09-01

    Ectoparasites inhabiting the skin are responsible for significant problems in small mammals, owing to ingestion of blood, lymph, sebaceous secretions, and scavenging skin debris, as well as a hypersensitivity reaction to parasite antigen resulting in severe pruritus and subsequent self-trauma-induced lesions. In general practice, the most common diagnosis in exotic pets is an unspecified mite infestation, but other ectoparasites such as lice, fleas, insects, or even helminths may cause dermatologic diseases. If treatment with topical insecticides is planned, the small mammal should be isolated for a few hours to enable drying and spreading of the product.

  15. Use of Nuclear Magnetic Resonance as an Experimental Probe in Multiphase Systems: Determination of the Instrument Weight Function for Measurements of Liquid-Phase Volume Fractions

    NASA Astrophysics Data System (ADS)

    Maneval, J. E.; McCarthy, M. J.; Whitaker, S.

    1990-11-01

    The relativist approach (Baveye and Sposito (1984)) to the interpretation of measurements in multiphase systems was proposed in order to incorporate the details of measurements into theoretical analyses of multiphase transport processes. To help establish the utility of this approach, the weight functions for actual experimental probes must be determined. In this paper we analyze the measurement of liquid-phase porosity in a model system by nuclear magnetic resonance imaging. We show how both nuclear magnetic resonance (NMR) physics and experimental technique combine to determine the weight function for the spin-warp spin-echo sequence. The analysis shows clearly what aspects of the weight function are determined by the experimental method and what aspects are determined by the system being studied. The results will help establish the utility of the relativist approach as well as improve understanding NMR measurements in multiphase systems.

  16. Exotic negative molecules in AMS

    NASA Astrophysics Data System (ADS)

    Golser, Robin; Gnaser, Hubert; Kutschera, Walter; Priller, Alfred; Steier, Peter; Wallner, Anton

    2007-06-01

    "The techniques and equipment developed for AMS studies are well suited for identifying exotic negative ions". With this sentence begins a pioneering paper by Roy Middleton and Jeff Klein (M&K) on small doubly-charged negative carbon clusters [Nucl. Instr. and Meth. B 123 (1997) 532]. M&K were the first to utilize Accelerator Mass Spectrometry to prove the existence of these clusters and a number of other exotic molecules. We review M&K's efforts and show how their work is being continued at other laboratories. The latest developments are: (1) the discovery of long-lived molecular hydrogen anions H2-,D2-and (2) the unambiguous identification of the smallest doubly-charged negative molecule (LiF3)2-. In particular we show new experimental data for D3-, and for (LiF3)2-, and we try to answer the question why M&K's search for this di-anion was unsuccessful.

  17. Heavy exotic molecules with charm and bottom

    NASA Astrophysics Data System (ADS)

    Liu, Yizhuang; Zahed, Ismail

    2016-11-01

    We revisit the formation of pion-mediated heavy-light exotic molecules with both charm and bottom and their chiral partners under the general strictures of both heavy-quark and chiral symmetry. The chiral exotic partners with good parity formed using the (0+ ,1+) multiplet are about twice more bound than their primary exotic partners formed using the (0- ,1-) multiplet. The chiral couplings across the multiplets (0± ,1±) cause the chiral exotic partners to unbind, and the primary exotic molecules to be about twice more bound, for J ≤ 1. Our multi-channel coupling results show that only the charm isosinglet exotic molecules with JPC =1++ bind, which we identify as the reported neutral X (3872). Also, the bottom isotriplet exotic with JPC =1+- binds, which we identify as a mixture of the reported charged exotics Zb+ (10610) and Zb+ (10650). The bound isosinglet with JPC =1++ is suggested as a possible neutral Xb (10532) not yet reported.

  18. Probing the effective nuclear-spin magnetic field in a single quantum dot via full counting statistics

    SciTech Connect

    Xue, Hai-Bin; Nie, Yi-Hang; Chen, Jingzhe; Ren, Wei

    2015-03-15

    We study theoretically the full counting statistics of electron transport through a quantum dot weakly coupled to two ferromagnetic leads, in which an effective nuclear-spin magnetic field originating from the configuration of nuclear spins is considered. We demonstrate that the quantum coherence between the two singly-occupied eigenstates and the spin polarization of two ferromagnetic leads play an important role in the formation of super-Poissonian noise. In particular, the orientation and magnitude of the effective field have a significant influence on the variations of the values of high-order cumulants, and the variations of the skewness and kurtosis values are more sensitive to the orientation and magnitude of the effective field than the shot noise. Thus, the high-order cumulants of transport current can be used to qualitatively extract information on the orientation and magnitude of the effective nuclear-spin magnetic field in a single quantum dot. - Highlights: • The effective nuclear-spin magnetic field gives rise to the off-diagonal elements of the reduced density matrix of single QD. • The off-diagonal elements of reduced density matrix of the QD have a significant impact on the high-order current cumulants. • The high-order current cumulants are sensitive to the orientation and magnitude of the effective nuclear-spin magnetic field. • The FCS can be used to detect the orientation and magnitude of the effective nuclear-spin magnetic field in a single QD.

  19. Large acceptance spectrometers for invariant mass spectroscopy of exotic nuclei and future developments

    NASA Astrophysics Data System (ADS)

    Nakamura, T.; Kondo, Y.

    2016-06-01

    Large acceptance spectrometers at in-flight RI separators have played significant roles in investigating the structure of exotic nuclei. Such spectrometers are in particular useful for probing unbound states of exotic nuclei, using invariant mass spectroscopy with reactions at intermediate and high energies. We discuss here the key characteristic features of such spectrometers, by introducing the recently commissioned SAMURAI facility at the RIBF, RIKEN. We also investigate the issue of cross talk in the detection of multiple neutrons, which has become crucial for exploring further unbound states and nuclei beyond the neutron drip line. Finally we discuss future perspectives for large acceptance spectrometers at the new-generation RI-beam facilities.

  20. Swift Probes Exotic Object: 'Kicked' Black Hole or Mega Star?

    NASA Video Gallery

    Zoom into Markarian 177 and SDSS1133 and see how they compare with a simulated galaxy collision. When the central black holes in these galaxies combine, a "kick" launches the merged black hole on a...

  1. Photoproduction of exotic baryon resonances

    NASA Astrophysics Data System (ADS)

    Karliner, Marek; Rosner, Jonathan L.

    2016-01-01

    We point out that the new exotic resonances recently reported by LHCb in the J / ψ p channel are excellent candidates for photoproduction off a proton target. This test is crucial to confirming the resonant nature of such states, as opposed to their being kinematical effects. We specialize to an interpretation of the heavier narrow state as a molecule composed of Σc and Dbar*, and estimate its production cross section using vector dominance. The relevant photon energies and fluxes are well within the capabilities of the GlueX and CLAS12 detectors at Thomas Jefferson National Accelerator Facility (JLAB). A corresponding calculation is also performed for photoproduction of an analogous resonance which is predicted to exist in the ϒp channel.

  2. Exotic Hadrons from B Factories

    NASA Astrophysics Data System (ADS)

    Fulsom, Bryan

    2017-01-01

    The first generation of B-Factories, BaBar and Belle, operated over the previous decade and produced many world-leading measurements related to flavor physics. One of the most important discoveries was that of an apparent four-quark particle, named X(3872). It was the first of a growing X, Y, Z alphabet of exotic hadrons, now numbering more than a dozen, found by the e + e - collider experiments. These multi-quark states represent an unusual departure from the standard description that hadronic matter consists of only two or three quarks. These discoveries have led to the emergence of a new category of physics within heavy meson spectroscopy. This talk will review some of these key experimental results, and highlight the potential of the next generation B-Factory, Belle II, as it begins operation in the coming year.

  3. Solar Neutrinos with Exotic Scattering

    NASA Astrophysics Data System (ADS)

    Pulido, João

    The possibility of unconventional neutrino scattering in the Sun via flavor changing neutral currents as a possible source of the solar neutrino deficit is investigated. If the effect is really significant, a resonant process will occur. Taking into account the neutrino deficit reported by the solar neutrino experiments (Kamiokande II, SAGE Gallex), one finds Δ2m21 = (0.6-1.4) × 10-5 eV2 with no vacuum mixing and 0.16 ≤ fex ≤ 0.34 where fex is the lepton violating coupling. Our understanding of the neutrino phenomenon in the Sun may be improved through accuracy improvements in experiments measuring νee- elastic scattering or others searching for exotic lepton decays.

  4. Exotic tracers for atmospheric studies

    NASA Astrophysics Data System (ADS)

    Lovelock, James E.; Ferber, Gilbert J.

    Tracer materials can be injected into the atmosphere to study transport and dispersion processes and to validate air pollution model calculations. Tracers should be inert, non-toxic and harmless to the environment. Tracers for long-range experiments, where dilution is very great, must be measurable at extremely low concentrations, well below the parts per trillion level. Compounds suitable for long-range tracer work are rare and efforts should be made to reserve them for meteorological studies, barring them from commercial uses which would increase atmospheric background concentrations. The use of these exotic tracers, including certain perfluorocarbons and isotopically labelled methanes, should be coordinated within the meteorological community to minimize interferences and maximize research benefits.

  5. How exotic plants integrate into pollination networks

    PubMed Central

    Stouffer, Daniel B; Cirtwill, Alyssa R; Bascompte, Jordi; Bartomeus, Ignasi

    2014-01-01

    Summary There is increasing world-wide concern about the impact of the introduction of exotic species on ecological communities. Since many exotic plants depend on native pollinators to successfully establish, it is of paramount importance that we understand precisely how exotic species integrate into existing plant–pollinator communities. In this manuscript, we have studied a global data base of empirical pollination networks to determine whether community, network, species or interaction characteristics can help identify invaded communities. We found that a limited number of community and network properties showed significant differences across the empirical data sets – namely networks with exotic plants present are characterized by greater total, plant and pollinator richness, as well as higher values of relative nestedness. We also observed significant differences in terms of the pollinators that interact with the exotic plants. In particular, we found that specialist pollinators that are also weak contributors to community nestedness are far more likely to interact with exotic plants than would be expected by chance alone. Synthesis. By virtue of their interactions, it appears that exotic plants may provide a key service to a community's specialist pollinators as well as fill otherwise vacant ‘coevolutionary niches’. PMID:25558089

  6. The program at JPL to investigate the nuclear interaction of RTG's with scientific instruments on deep space probes

    NASA Technical Reports Server (NTRS)

    Truscello, V.

    1972-01-01

    A major concern in the integration of a radioisotope thermoelectric generator (RTG) with a spacecraft designed to explore the outer planets is the effect of the emitted radiation on the normal operation of scientific instruments. The necessary techniques and tools developed to allow accurate calculation of the neutron and gamma spectrum emanating from the RTG. The specific sources of radiation were identified and quantified. Monte Carlo techniques are then employed to perform the nuclear transport calculations. The results of these studies are presented. An extensive experimental program was initiated to measure the response of a number of scientific components to the nuclear radiation.

  7. Exotic mammals disperse exotic fungi that promote invasion by exotic trees.

    PubMed

    Nuñez, Martin A; Hayward, Jeremy; Horton, Thomas R; Amico, Guillermo C; Dimarco, Romina D; Barrios-Garcia, M Noelia; Simberloff, Daniel

    2013-01-01

    Biological invasions are often complex phenomena because many factors influence their outcome. One key aspect is how non-natives interact with the local biota. Interaction with local species may be especially important for exotic species that require an obligatory mutualist, such as Pinaceae species that need ectomycorrhizal (EM) fungi. EM fungi and seeds of Pinaceae disperse independently, so they may use different vectors. We studied the role of exotic mammals as dispersal agents of EM fungi on Isla Victoria, Argentina, where many Pinaceae species have been introduced. Only a few of these tree species have become invasive, and they are found in high densities only near plantations, partly because these Pinaceae trees lack proper EM fungi when their seeds land far from plantations. Native mammals (a dwarf deer and rodents) are rare around plantations and do not appear to play a role in these invasions. With greenhouse experiments using animal feces as inoculum, plus observational and molecular studies, we found that wild boar and deer, both non-native, are dispersing EM fungi. Approximately 30% of the Pinaceae seedlings growing with feces of wild boar and 15% of the seedlings growing with deer feces were colonized by non-native EM fungi. Seedlings growing in control pots were not colonized by EM fungi. We found a low diversity of fungi colonizing the seedlings, with the hypogeous Rhizopogon as the most abundant genus. Wild boar, a recent introduction to the island, appear to be the main animal dispersing the fungi and may be playing a key role in facilitating the invasion of pine trees and even triggering their spread. These results show that interactions among non-natives help explain pine invasions in our study area.

  8. Exotic Mammals Disperse Exotic Fungi That Promote Invasion by Exotic Trees

    PubMed Central

    Nuñez, Martin A.; Hayward, Jeremy; Horton, Thomas R.; Amico, Guillermo C.; Dimarco, Romina D.; Barrios-Garcia, M. Noelia; Simberloff, Daniel

    2013-01-01

    Biological invasions are often complex phenomena because many factors influence their outcome. One key aspect is how non-natives interact with the local biota. Interaction with local species may be especially important for exotic species that require an obligatory mutualist, such as Pinaceae species that need ectomycorrhizal (EM) fungi. EM fungi and seeds of Pinaceae disperse independently, so they may use different vectors. We studied the role of exotic mammals as dispersal agents of EM fungi on Isla Victoria, Argentina, where many Pinaceae species have been introduced. Only a few of these tree species have become invasive, and they are found in high densities only near plantations, partly because these Pinaceae trees lack proper EM fungi when their seeds land far from plantations. Native mammals (a dwarf deer and rodents) are rare around plantations and do not appear to play a role in these invasions. With greenhouse experiments using animal feces as inoculum, plus observational and molecular studies, we found that wild boar and deer, both non-native, are dispersing EM fungi. Approximately 30% of the Pinaceae seedlings growing with feces of wild boar and 15% of the seedlings growing with deer feces were colonized by non-native EM fungi. Seedlings growing in control pots were not colonized by EM fungi. We found a low diversity of fungi colonizing the seedlings, with the hypogeous Rhizopogon as the most abundant genus. Wild boar, a recent introduction to the island, appear to be the main animal dispersing the fungi and may be playing a key role in facilitating the invasion of pine trees and even triggering their spread. These results show that interactions among non-natives help explain pine invasions in our study area. PMID:23826154

  9. Issues and opportunities in exotic hadrons

    SciTech Connect

    Briceno, Raul A.; Cohen, Thomas D.; Coito, S.; Dudek, Jozef J.; Eichten, E.; Fischer, C. S.; Fritsch, M.; Gradl, W.; Jackura, A.; Kornicer, M.; Krein, G.; Lebed, Richard F.; Machado, F. A.; Mitchell, R. E.; Morningstar, C. J.; Peardon, M.; R. Pennington, M.; Peters, K.; M. Richard, J.; P. Shen, C.; Shepherd, M. R.; Skwarnicki, T.; S. Swanson, E.; Szczepaniak, A. P.; Yuan, C. Z.

    2016-04-01

    The last few years have been witness to a proliferation of new results concerning heavy exotic hadrons. Experimentally, many new signals have been discovered that could be pointing towards the existence of tetraquarks, pentaquarks, and other exotic configurations of quarks and gluons. Theoretically, advances in lattice field theory techniques place us at the cusp of understanding complex coupled-channel phenomena, modelling grows more sophisticated, and effective field theories are being applied to an ever greater range of situations. Consequently, it is thus an opportune time to evaluate the status of the field. In the following, a series of high priority experimental and theoretical issues concerning heavy exotic hadrons is presented.

  10. New measurement of exotic decay of 225Ac by 14C emission

    NASA Astrophysics Data System (ADS)

    Guglielmetti, A.; Bonetti, R.; Ardisson, G.; Barci, V.; Giles, T.; Hussonnois, M.; Le Du, J. F.; Le Naour, C.; Mikheev, V. L.; Pasinetti, A. L.; Ravn, H. L.; Tretyakova, S. P.; Trubert, D.

    The branching ratio of 225Ac decay by emission of 14C was remeasured under improved experimental conditions by using a radioactive source produced at the ISOLDE mass-separator at CERN and a nuclear track detector technique. The result, B = λ14C/λα = (4.5+/-1.4)10-12, is consistent with the anomalously high value obtained in the 1993 experiment, thus confirming the importance of nuclear-structure effects in this exotic decay.

  11. EDITORIAL: Focus on Superconductors with Exotic Symmetries FOCUS ON SUPERCONDUCTORS WITH EXOTIC SYMMETRIES

    NASA Astrophysics Data System (ADS)

    Rice, T. Maurice; Sigrist, Manfred; Maeno, Yoshiteru

    2009-05-01

    here and a consistent theoretical description of all aspects of their superconductivity remains a formidable challenge. While the discovery of the BCS theory led, in only a few years, to the complete and consistent theoretical description of all aspects of conventional superconductivity, we are far from this goal for the exotic superconductors. Hence these superconductors continue to be the focus of most research activity in the field of superconductivity today. The papers in this special issue represent a cross section of current activity in both experiment and theory on these fascinating materials. Focus on Superconductors with Exotic Symmetries Contents Phase-sensitive-measurement determination of odd-parity, spin-triplet superconductivity in Sr2RuO4 Ying Liu Striped superconductors: how spin, charge and superconducting orders intertwine in the cuprates Erez Berg, Eduardo Fradkin, Steven A Kivelson and John M Tranquada A twisted ladder: relating the Fe superconductors to the high-Tc cuprates E Berg, S A Kivelson and D J Scalapino Fractional vortex lattice structures in spin-triplet superconductors Suk Bum Chung, Daniel F Agterberg and Eun-A Kim Momentum dependence of pseudo-gap and superconducting gap in variation theory T Watanabe, H Yokoyama, K Shigeta and M Ogata Variational ground states of the two-dimensional Hubbard model D Baeriswyl, D Eichenberger and M Menteshashvili Charge dynamics of vortex cores in layered chiral triplet superconductors M Eschrig and J A Sauls Vortices in chiral, spin-triplet superconductors and superfluids J A Sauls and M Eschrig Flux periodicities in loops of nodal superconductors Florian Loder, Arno P Kampf, Thilo Kopp and Jochen Mannhart Evidence of magnetic mechanism for cuprate superconductivity Amit Keren Wave function for odd-frequency superconductors Hari P Dahal, E Abrahams, D Mozyrsky, Y Tanaka and A V Balatsky Nernst effect as a probe of superconducting fluctuations in disordered thin films A Pourret, P Spathis, H Aubin and K

  12. Nuclear Structure Near the Drip Lines

    SciTech Connect

    Nazarewicz, W.

    1998-08-10

    Experiments with beams of unstable nuclei will make it possible to look closely into many aspects of the nuclear many-body problem. Theoretically, exotic nuclei represent a formidable challenge for the nuclear many-body theories and their power to predict nuclear properties in nuclear terra incognita.

  13. Disulfide-Trapping Identifies a New, Effective Chemical Probe for Activating the Nuclear Receptor Human LRH-1 (NR5A2)

    PubMed Central

    de Jesus Cortez, Felipe; Suzawa, Miyuki; Irvy, Sam; Bruning, John M.; Sablin, Elena; Jacobson, Matthew P.; Fletterick, Robert J.; Ingraham, Holly A.

    2016-01-01

    Conventional efforts relying on high-throughput physical and virtual screening of large compound libraries have failed to yield high-efficiency chemical probes for many of the 48 human nuclear receptors. Here, we investigated whether disulfide-trapping, an approach new to nuclear receptors, would provide effective lead compounds targeting human liver receptor homolog 1 (hLRH-1, NR5A2). Despite the fact that hLRH-1 contains a large ligand binding pocket and binds phospholipids with high affinity, existing synthetic hLRH-1 ligands are of limited utility due to poor solubility, low efficacy or significant off-target effects. Using disulfide-trapping, we identified a lead compound that conjugates with remarkably high-efficiency to a native cysteine residue (Cys346) lining the hydrophobic cavity in the ligand binding domain of hLRH-1. Guided by computational modeling and cellular assays, the lead compound was elaborated into ligands PME8 and PME9 that bind hLRH-1 reversibly (no cysteine reactivity) and increase hLRH-1 activity in cells. When compared with the existing hLRH-1 synthetic agonist RJW100, both PME8 and PME9 showed comparable induction of the LRH-1 dependent target gene CYP24A1 in human HepG2 cells, beginning as early as 3 h after drug treatment. The induction is specific as siRNA-mediated knock-down of hLRH-1 renders both PME8 and PME9 ineffective. These data show that PME8 and PME9 are potent activators of hLRH-1 and suggest that with further development this lead series may yield useful chemical probes for manipulating LRH-1 activity in vivo. PMID:27467220

  14. Advances in exotic mammal clinical therapeutics.

    PubMed

    Hawkins, Michelle G

    2015-05-01

    It is important that veterinarians treating exotic companion mammals stay abreast of the latest developments relating to medications and drug delivery approaches for safety, efficacy and welfare issues. Sustained release formulations of commonly used drugs as well as newer routes for administration of therapeutic agents allow the veterinarian treating exotic companion mammals to reduce the stress associated with drug administration. Interactions can occur between vehicle and drugs when formulations are compounded, therefore research studies are warranted regarding potential problems associated with these formulations.

  15. Volume integral theorem for exotic matter

    SciTech Connect

    Nandi, Kamal Kanti; Zhang Yuanzhong; Kumar, K.B. Vijaya

    2004-12-15

    We answer an important question in general relativity about the volume integral theorem for exotic matter by suggesting an exact integral quantifier for matter violating Averaged Null Energy Condition (ANEC). It is checked against some well-known static, spherically symmetric traversable wormhole solutions of general relativity with a sign reversed kinetic term minimally coupled scalar field. The improved quantifier is consistent with the principle that traversable wormholes can be supported by arbitrarily small quantities of exotic matter.

  16. Search for exotic particles at CDF

    SciTech Connect

    Gold, M.S.

    1992-10-01

    We have searched for exotic particles in p[bar p] collisions at 1.8 TeV in data taken with the Collider Detector at Fermilab. We review our published limits on W[prime] and Z[prime] masses, and on the scale of lepton-quark compositeness. We also report preliminary mass limits based on searches for leptoquarks, supersymmetric quarks and gluons, and exotic, stable colored fermions.

  17. Indole-based cyanine as a nuclear RNA-selective two-photon fluorescent probe for live cell imaging.

    PubMed

    Guo, Lei; Chan, Miu Shan; Xu, Di; Tam, Dick Yan; Bolze, Frédéric; Lo, Pik Kwan; Wong, Man Shing

    2015-05-15

    We have demonstrated that the subcellular targeting properties of the indole-based cyanines can be tuned by the functional substituent attached onto the indole moiety in which the first example of a highly RNA-selective and two-photon active fluorescent light-up probe for high contrast and brightness TPEF images of rRNA in the nucleolus of live cells has been developed. It is important to find that this cyanine binds much stronger toward RNA than DNA in a buffer solution as well as selectively stains and targets to rRNA in the nucleolus. Remarkably, the TPEF brightness (Φσmax) is dramatically increased with 11-fold enhancement in the presence of rRNA, leading to the record high Φσmax of 228 GM for RNA. This probe not only shows good biocompatibility and superior photostability but also offers general applicability to various live cell lines including HeLa, HepG2, MCF-7, and KB cells and excellent counterstaining compatibility with commercially available DNA or protein trackers.

  18. Pathways to exotic metastable silicon allotropes

    DOE PAGES

    Haberl, Bianca; Strobel, Timothy A.; Bradby, Jodie E.

    2016-09-27

    The Group 14 element silicon possesses a complex free-energy landscape with many (local) minima, allowing for the formation of a variety of unusual structures, some of which may be stabilized at ambient conditions. Such exotic silicon allotropes represent a significant opportunity to address the ever-increasing demand for novel materials with tailored functionality since these exotic forms are expected to exhibit superlative properties including optimized band gaps for solar power conversion. The application of pressure is a well-recognized and uniquely powerful method to access exotic states of silicon since it promotes large changes to atomic bonding. Conventional high-pressure syntheses, however, lackmore » the capability to access many of these local minima and only four forms of exotic silicon allotropes have been recovered over the last 50 years. However, more recently, signifi- cant advances in high pressure methodologies and the use of novel precursor materials have yielded at least three more recoverable exotic Si structures. This review aims to give an overview of these innovative methods of high-pressure application and precursor selection and the recent discoveries of new Si allotropes. The background context of the conventional pressure methods and multitude of predicted new phases are also provided. Furthermore, this review also offers a perspective for possible access to many further exotic functional allotropes not only of silicon but also of other materials, in a technologically feasible manner« less

  19. Exotic Meson Results from BNL E852

    NASA Astrophysics Data System (ADS)

    Manak, Joseph J.

    1998-10-01

    Results from BNL experiment 852 on exotic (non-q\\overlineq) meson production are presented. Production of final states with J^PC = 1^-+ is observed in π^-p interactions at 18 GeV/c in the ηπ^-, ρπ^- and η^'π^- channels. Since such states are manifestly exotic if they are resonant, we describe amplitude analyses which use the interference between these states and other well known states to measure the phase behavior of the J^PC = 1^-+ amplitudes. The analyses show that, in addition to the previously reported(D.R. Thompson et al.), Phys. Rev. Lett. 79, 1630 (1997) evidence for an exotic meson in the ηπ^- channel, there is strong evidence for a second exotic meson decaying to ρπ^- with a mass of M=1593 ±8^+29_-47 MeV/c^2 and a width of Γ=168 ±20^+150_-12 MeV/c^2. We also show that the η^'π^- system is dominated by J^PC = 1^-+ production and we use those data to determine decay branching ratios for the exotic mesons. Such measurements are expected to be crucial in determining the constituent nature of the exotic mesons - that is, whether they are consistent with being hybrid mesons or four-quark states.

  20. Pathways to exotic metastable silicon allotropes

    NASA Astrophysics Data System (ADS)

    Haberl, Bianca; Strobel, Timothy A.; Bradby, Jodie E.

    2016-12-01

    The Group 14 element silicon possesses a complex free-energy landscape with many (local) minima, allowing for the formation of a variety of unusual structures, some of which may be stabilized at ambient conditions. Such exotic silicon allotropes represent a significant opportunity to address the ever-increasing demand for novel materials with tailored functionality since these exotic forms are expected to exhibit superlative properties including optimized band gaps for solar power conversion. The application of pressure is a well-recognized and uniquely powerful method to access exotic states of silicon since it promotes large changes to atomic bonding. Conventional high-pressure syntheses, however, lack the capability to access many of these local minima and only four forms of exotic silicon allotropes have been recovered over the last 50 years. However, more recently, significant advances in high pressure methodologies and the use of novel precursor materials have yielded at least three more recoverable exotic Si structures. This review aims to give an overview of these innovative methods of high-pressure application and precursor selection and the recent discoveries of new Si allotropes. The background context of the conventional pressure methods and multitude of predicted new phases are also provided. This review also offers a perspective for possible access to many further exotic functional allotropes not only of silicon but also of other materials, in a technologically feasible manner.

  1. Pathways to exotic metastable silicon allotropes

    SciTech Connect

    Haberl, Bianca; Strobel, Timothy A.; Bradby, Jodie E.

    2016-09-27

    The Group 14 element silicon possesses a complex free-energy landscape with many (local) minima, allowing for the formation of a variety of unusual structures, some of which may be stabilized at ambient conditions. Such exotic silicon allotropes represent a significant opportunity to address the ever-increasing demand for novel materials with tailored functionality since these exotic forms are expected to exhibit superlative properties including optimized band gaps for solar power conversion. The application of pressure is a well-recognized and uniquely powerful method to access exotic states of silicon since it promotes large changes to atomic bonding. Conventional high-pressure syntheses, however, lack the capability to access many of these local minima and only four forms of exotic silicon allotropes have been recovered over the last 50 years. However, more recently, signifi- cant advances in high pressure methodologies and the use of novel precursor materials have yielded at least three more recoverable exotic Si structures. This review aims to give an overview of these innovative methods of high-pressure application and precursor selection and the recent discoveries of new Si allotropes. The background context of the conventional pressure methods and multitude of predicted new phases are also provided. Furthermore, this review also offers a perspective for possible access to many further exotic functional allotropes not only of silicon but also of other materials, in a technologically feasible manner

  2. Probing the specificity of binding to the major nuclear localization sequence-binding site of importin-alpha using oriented peptide library screening.

    PubMed

    Yang, Sundy N Y; Takeda, Agnes A S; Fontes, Marcos R M; Harris, Jonathan M; Jans, David A; Kobe, Bostjan

    2010-06-25

    Importin-alpha is the nuclear import receptor that recognizes the classic monopartite and bipartite nuclear localization sequences (cNLSs), which contain one or two clusters of basic amino acids, respectively. Different importin-alpha paralogs in a single organism are specific for distinct repertoires of cargos. Structural studies revealed that monopartite cNLSs and the C-terminal basic clusters of the bipartite cNLSs bind to the same site on importin-alpha, termed the major cNLS-binding site. We used an oriented peptide library approach with five degenerate positions to probe the specificity of the major cNLS-binding site in importin-alpha. We identified the sequences KKKRR, KKKRK, and KKRKK as the optimal sequences for binding to this site for mouse importin-alpha2, human importin-alpha1, and human importin-alpha5, respectively. The crystal structure of mouse importin-alpha2 with its optimal peptide confirmed the expected binding mode resembling the binding of simian virus 40 large tumor-antigen cNLS. Binding assays confirmed that the peptides containing these sequences bound to the corresponding proteins with low nanomolar affinities. Nuclear import assays showed that the sequences acted as functional cNLSs, with specificity for particular importin-alphas. This is the first time that structural information has been linked to an oriented peptide library screening approach for importin-alpha; the results will contribute to understanding of the sequence determinants of cNLSs, and may help identify as yet unidentified cNLSs in novel proteins.

  3. Probing nuclear shapes close to the fission limit with the giant dipole resonance in {sup 216}Rn

    SciTech Connect

    Kmiecik, M.; Maj, A.; Brekiesz, M.; Krolas, W.; Meczynski, W.; Styczen, J.; Zieblinski, M.; Million, B.; Bracco, A.; Camera, F.; Benzoni, G.; Leoni, S.; Wieland, O.; Brambilla, S.; Herskind, B.; Kicinska-Habior, M.; Dubray, N.; Dudek, J.; Schunck, N.

    2004-12-01

    The gamma-ray decay of the giant dipole resonance (GDR) in the compound nucleus {sup 216}Rn formed with the reaction {sup 18}O+{sup 198}Pt at the bombarding energy of 96 MeV was investigated. High-energy gamma-ray spectra in coincidence with both prompt and delayed low-energy transitions were measured. The obtained GDR width at the average temperature {approx_equal}1 MeV was found to be larger than that at T=0 MeV and to be approximately constant as a function of spin. The measured width value of 7 MeV is found to be consistent with the predictions based on calculations of the nuclear shape distribution using the newest approach for the treatment of the fission barrier within the liquid drop model. The present study is the first investigation of the giant dipole resonance width from the fusion-evaporation decay channel in this nuclear mass range.

  4. Distinctive exotic flavor and aroma compounds of some exotic tropical fruits and berries: a review.

    PubMed

    Lasekan, Ola; Abbas, Kassim A

    2012-01-01

    The characteristic flavor of exotic tropical fruits is one of their most attractive attributes to consumers. In this article, the enormous diversity of exotic fruit flavors is reviewed. Classifying some of the exotic fruits into two classes on the basis of whether esters or terpenes predominate in the aroma was also attempted. Indeed, as far as exotic tropical fruits are concerned, the majority of fruits have terpenes predominating in their aroma profile. Some of the fruits in this group are the Amazonian fruits such as pitanga, umbu-caja, camu-camu, garcinia, and bacuri. The ester group is made up of rambutan, durians, star fruit, snake fruit, acerola, tamarind, sapodilla, genipap, soursop, cashew, melon, jackfruit, and cupuacu respectively. Also, the role of sulphur-volatiles in some of the exotic fruits is detailed.

  5. Ab initio valence-space theory for exotic nuclei

    NASA Astrophysics Data System (ADS)

    Holt, Jason

    2015-10-01

    Recent advances in ab initio nuclear structure theory have led to groundbreaking predictions in the exotic medium-mass region, from the location of the neutron dripline to the emergence of new magic numbers far from stability. Playing a key role in this progress has been the development of sophisticated many-body techniques and chiral effective field theory, which provides a systematic basis for consistent many-nucleon forces and electroweak currents. Within the context of valence-space Hamiltonians derived from the nonperturbative in-medium similarity renormalization group (IM-SRG) approach, I will discuss the importance of 3N forces in understanding and making new discoveries in the exotic sd -shell region. Beginning in oxygen, we find that the effects of 3N forces are decisive in explaining why 24O is the last bound oxygen isotope, validating first predictions of this phenomenon from several years ago. Furthermore, 3N forces play a key role in reproducing spectroscopy, including signatures of doubly magic 22,24O, and physics beyond the dripline. Similar improvements are obtained in new spectroscopic predictions for exotic fluorine and neon isotopes, where agreement with recent experimental data is competitive with state-of-the-art phenomenology. Finally, I will discuss first applications of the IM-SRG to effective valence-space operators, such as radii and E 0 transitions, as well as extensions to general operators crucial for our future understanding of electroweak processes, such as neutrinoless double-beta decay. This work was supported by NSERC and the NRC Canada.

  6. PROBING THE FERMI BUBBLES IN ULTRAVIOLET ABSORPTION: A SPECTROSCOPIC SIGNATURE OF THE MILKY WAY'S BICONICAL NUCLEAR OUTFLOW

    SciTech Connect

    Fox, Andrew J.; Bordoloi, Rongmon; Hernandez, Svea; Tumlinson, Jason; Savage, Blair D.; Wakker, Bart P.; Lockman, Felix J.; Bland-Hawthorn, Joss; Kim, Tae-Sun; Benjamin, Robert A.

    2015-01-20

    Giant lobes of plasma extend ≈55° above and below the Galactic center, glowing in emission from gamma rays (the Fermi Bubbles) to microwaves and polarized radio waves. We use ultraviolet absorption-line spectra from the Hubble Space Telescope to constrain the velocity of the outflowing gas within these regions, targeting the quasar PDS 456 (ℓ, b = 10.°4, +11.°2). This sightline passes through a clear biconical structure seen in hard X-ray and gamma-ray emission near the base of the northern Fermi Bubble. We report two high-velocity metal absorption components, at v {sub LSR} = –235 and +250 km s{sup –1}, which cannot be explained by co-rotating gas in the Galactic disk or halo. Their velocities are suggestive of an origin on the front and back side of an expanding biconical outflow emanating from the Galactic center. We develop simple kinematic biconical outflow models that can explain the observed profiles with an outflow velocity of ≳900 km s{sup –1} and a full opening angle of ≈110° (matching the X-ray bicone). This indicates Galactic center activity over the last ≈2.5-4.0 Myr, in line with age estimates of the Fermi Bubbles. The observations illustrate the use of UV spectroscopy to probe the properties of swept-up gas venting into the Fermi Bubbles.

  7. Assigning {gamma} deformation from fine structure in exotic nuclei

    SciTech Connect

    Ferreira, L. S.; Maglione, E.; Arumugam, P.

    2011-10-28

    The nonadiabatic quasiparticle model for triaxial shapes is used to perform calculations for decay of {sup 141}Ho, the only known odd-Z even-N deformed nucleus for which fine structure in proton emission from both ground and isomeric states has been observed. All experimental data corresponding to this unique case namely, the rotational spectra of parent and daughter nuclei, decay widths and branching ratios for ground and isomeric states, could be well explained with a strong triaxial deformation {gamma}{approx}20. The recent experimental observation of fine structure decay from the isomeric state, can be explained only with an assignment of I{sup {pi}} = 3/2{sup +} as the decaying state, in contradiction with the previous assignment, of I{sup {pi}} 1/2{sup +}, based on adiabatic calculations. This study reveals that proton emission measurements could be a precise tool to probe triaxial deformations and other structural properties of exotic nuclei beyond the proton dripline.

  8. Injuries, envenomations and stings from exotic pets.

    PubMed

    Warwick, Clifford; Steedman, Catrina

    2012-07-01

    A variety of exotic vertebrate and invertebrate species are kept as 'pets' including fishes, amphibians (for example, frogs and toads), reptiles (turtles, crocodiles, lizards and snakes), birds, mammals (for example, primates, civets, and lions), and invertebrates (for example spiders, scorpions, and centipedes), and ownership of some of these animals is rising. Data for 2009-2011 suggest that the number of homes with reptiles rose by approximately 12.5%. Recent surveys, including only some of these animals, indicated that they might be present in around 18.6% of homes (equal to approximately 42 million animals of which around 40 million are indoor or outdoor fish). Many exotic 'pets' are capable of causing injury or poisoning to their keepers and some contacts prove fatal. We examined NHS Health Episode Statistics for England using selected formal categories for hospital admissions and bed days for 2004-2010 using the following categories of injury, envenomation or sting; bitten or struck by crocodile or alligator; bitten or crushed by other reptiles: contact with venomous snakes and lizards; contact with scorpions. Between 2004 and 2010 these data conservatively show a total of 760 full consultation episodes, 709 admissions and 2,121 hospital bed days were associated with injuries probably from exotic pets. Injuries, envenomations and stings from exotic pets constitute a small but important component of emerging medical problems. Greater awareness of relevant injuries and medical sequelae from exotic pet keeping may help medics formulate their clinical assessment and advice to patients.

  9. Probing the Fermi Bubbles in Ultraviolet Absorption: A Spectroscopic Signature of the Milky Way's Biconical Nuclear Outflow

    NASA Astrophysics Data System (ADS)

    Fox, Andrew J.; Bordoloi, Rongmon; Savage, Blair D.; Lockman, Felix J.; Jenkins, Edward B.; Wakker, Bart P.; Bland-Hawthorn, Joss; Hernandez, Svea; Kim, Tae-Sun; Benjamin, Robert A.; Bowen, David V.; Tumlinson, Jason

    2015-01-01

    Giant lobes of plasma extend ≈55° above and below the Galactic center, glowing in emission from gamma rays (the Fermi Bubbles) to microwaves and polarized radio waves. We use ultraviolet absorption-line spectra from the Hubble Space Telescope to constrain the velocity of the outflowing gas within these regions, targeting the quasar PDS 456 (l, b = 10.°4, +11.°2). This sightline passes through a clear biconical structure seen in hard X-ray and gamma-ray emission near the base of the northern Fermi Bubble. We report two high-velocity metal absorption components, at v LSR = -235 and +250 km s-1, which cannot be explained by co-rotating gas in the Galactic disk or halo. Their velocities are suggestive of an origin on the front and back side of an expanding biconical outflow emanating from the Galactic center. We develop simple kinematic biconical outflow models that can explain the observed profiles with an outflow velocity of gsim900 km s-1 and a full opening angle of ≈110° (matching the X-ray bicone). This indicates Galactic center activity over the last ≈2.5-4.0 Myr, in line with age estimates of the Fermi Bubbles. The observations illustrate the use of UV spectroscopy to probe the properties of swept-up gas venting into the Fermi Bubbles. Based on observations taken under program 13448 of the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555, and under program 14B-299 of the NRAO Green Bank Telescope, which is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  10. The characterization of phospholipid functional group probe species on respirable silicon-containing dusts by solid-state 13C and 31P nuclear magnetic resonance spectroscopy.

    PubMed

    Murray, David K

    2010-03-01

    Solid-state nuclear magnetic resonance (NMR) spectroscopic studies are reported for the interactions of probe molecules with respirable silicon-containing dusts as experimental evidence complementing computational studies reported by Snyder and Madura recently in J. Phys. Chem. B 112, 7095 (2008). The selected probe molecules represent the individual functional groups of a model lung surfactant dipalmitoylphosphatidyl choline (DPPC) deposited on a respirable silica and kaolin from water solution. (13)C and (31)P solid-state NMR spectroscopies were employed to detect chemical shift, line width, and chemical shift anisotropy, providing experimental evidence of mobility and relaxation changes describing the site and orientation of surface-associated species. NMR results confirm that only the phosphate and adjacent carbons are immobilized by surface hydroxyls on kaolin, while these and the carbons of the cationic head group are likewise immobilized by surface silanols on Miu-U-Sil 5. The phosphates in phosphoryl- and phosphatidyl-cholines were the primary interaction sites, with additional weak coordination with the trimethylammonium cation species. Covalent Al-O-P formation is not likely a factor in in vivo or in vitro toxicity mechanisms of respirable silicon-containing materials, but is rather the result of dehydration or demethoxylation reactions occurring over time or during heating or reduced pressure used in preparing materials for NMR spectroscopic study. Hydration is a critical factor in the formation and preparation for spectroscopic observation of coated dusts. Care must be taken to ensure that products formed and studied correspond to species formed in vivo under suitable concentration and hydration conditions.

  11. Exotic few-body systems with a heavy meson

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Yasuhiro

    2014-09-01

    Hadron as an impurity bound in nuclei causes interesting phenomena which do not emerge in normal nuclei. These effects would give us the information not only on the internal structure of the nuclei, but also on the changing properties of the impurity in the nuclear medium. The hadron-nucleus systems have been studied in the light flavor sector, especially. However, a strong attraction between a heavy meson (Dbar and B) and a nucleon, provided by the one pion exchange potential (OPEP), was suggested recently. The OPEP is enhanced by the heavy quark spin symmetry which induces the mass degeneracy between the heavy pseudoscalar and vector mesons. The attraction motivates us to investigate the Dbar (B) nuclei having the exotic flavor structure. Hence, these bound states are stable against the strong decay. We discuss the possible existence of exotic few-body states realized as DbarNN and BNN. The OPEP between the Dbar (B) meson and the nucleon N is considered. By solving coupled channel equations for PNN and P* NN channels (P (P*) is the heavy pseudoscalar (vector) meson), we obtain new three-body bound states and resonances. In these states, the tensor force of the OPEP plays an important role to yield the attraction.

  12. Wildlife, Exotic Pets, and Emerging Zoonoses1

    PubMed Central

    Belotto, Albino; Meslin, François-Xavier

    2007-01-01

    Most emerging infectious diseases are zoonotic; wildlife constitutes a large and often unknown reservoir. Wildlife can also be a source for reemergence of previously controlled zoonoses. Although the discovery of such zoonoses is often related to better diagnostic tools, the leading causes of their emergence are human behavior and modifications to natural habitats (expansion of human populations and their encroachment on wildlife habitat), changes in agricultural practices, and globalization of trade. However, other factors include wildlife trade and translocation, live animal and bushmeat markets, consumption of exotic foods, development of ecotourism, access to petting zoos, and ownership of exotic pets. To reduce risk for emerging zoonoses, the public should be educated about the risks associated with wildlife, bushmeat, and exotic pet trades; and proper surveillance systems should be implemented. PMID:17370509

  13. Exotic Baryon Resonances in the Skyrme Model

    NASA Astrophysics Data System (ADS)

    Diakonov, Dmitri; Petrov, Victor

    We outline how one can understand the Skyrme model from the modern perspective. We review the quantization of the SU(3) rotations of the Skyrmion, leading to the exotic baryons that cannot be made of three quarks. It is shown that in the limit of large number of colors the lowest-mass exotic baryons can be studied from the kaon-Skyrmion scattering amplitudes, an approach known after Callan and Klebanov. We follow this approach and find, both analytically and numerically, a strong Θ+ resonance in the scattering amplitude that is traced to the rotational mode. The Skyrme model does predict an exotic resonance Θ+ but grossly overestimates the width. To understand better the factors affecting the width, it is computed by several methods giving, however, identical results. In particular, we show that insofar as the width is small, it can be found from the transition axial constant. The physics leading to a narrow Θ+ resonance is briefly reviewed and affirmed.

  14. Exotic Superconductivity in Correlated Electron Systems

    SciTech Connect

    Mu, Gang; Sandu, Viorel; Li, Wei; Shen, Bing

    2015-05-25

    Over the past decades, the search for high-Tc superconductivity (SC) and its novel superconducting mechanisms is one of the most challenging tasks of condensed matter physicists and material scientists, wherein the most striking achievement is the discovery of high-c and unconventional superconductivity in strongly correlated 3d-electron systems, such as cuprates and iron pnictides/chalcogenides. Those exotic superconductors display the behaviors beyond the scope of the BCS theory (in the SC states) and the Landau-Fermi liquid theory (in the normal states). In general, such exotic superconductivity can be seen as correlated electron systems, where there are strong interplays among charge, spin, orbital, and lattice degrees of freedom. Thus, we focus on the exotic superconductivity in materials with correlated electrons in the present special issue.

  15. Issues and opportunities in exotic hadrons

    DOE PAGES

    Briceno, Raul A.; Cohen, Thomas D.; Coito, S.; ...

    2016-04-01

    The last few years have been witness to a proliferation of new results concerning heavy exotic hadrons. Experimentally, many new signals have been discovered that could be pointing towards the existence of tetraquarks, pentaquarks, and other exotic configurations of quarks and gluons. Theoretically, advances in lattice field theory techniques place us at the cusp of understanding complex coupled-channel phenomena, modelling grows more sophisticated, and effective field theories are being applied to an ever greater range of situations. Consequently, it is thus an opportune time to evaluate the status of the field. In the following, a series of high priority experimentalmore » and theoretical issues concerning heavy exotic hadrons is presented.« less

  16. Novel chemistry of invasive exotic plants

    PubMed Central

    Cappuccino, Naomi; Arnason, J.Thor

    2006-01-01

    Of the many exotic plants that have become naturalized in North America, only a small proportion are pests capable of invading and dominating intact natural communities. In the present study, we tested the hypothesis that the most invasive plants are phytochemically unique in their new habitats. A comparison of exotic plant species that are highly invasive in North America with exotics that are widespread, but non-invasive revealed that the invasive plants were more likely to have potent secondary compounds that have not been reported from North American native plants. On average, the compounds found in the invasive plants were reported from fewer species, fewer genera and fewer families than those from non-invasive plants. Many of the unique phytochemicals from invasive plants have been reported to have multiple activities, including antiherbivore, antifungal, antimicrobial and allelopathic (phytotoxic) effects, which may provide the plants with several advantages in their new environments. PMID:17148359

  17. Exotic Superconductivity in Correlated Electron Systems

    DOE PAGES

    Mu, Gang; Sandu, Viorel; Li, Wei; ...

    2015-05-25

    Over the past decades, the search for high-Tc superconductivity (SC) and its novel superconducting mechanisms is one of the most challenging tasks of condensed matter physicists and material scientists, wherein the most striking achievement is the discovery of high-c and unconventional superconductivity in strongly correlated 3d-electron systems, such as cuprates and iron pnictides/chalcogenides. Those exotic superconductors display the behaviors beyond the scope of the BCS theory (in the SC states) and the Landau-Fermi liquid theory (in the normal states). In general, such exotic superconductivity can be seen as correlated electron systems, where there are strong interplays among charge, spin, orbital,more » and lattice degrees of freedom. Thus, we focus on the exotic superconductivity in materials with correlated electrons in the present special issue.« less

  18. Nuclear Magnetic Resonance as a Probe of Meso-timescale Dynamics: Ion and H2O Behavior at Mineral-H2O Interfaces

    NASA Astrophysics Data System (ADS)

    Bowers, G. M.; Kirkpatrick, R. J.; Singer, J. W.

    2012-12-01

    One of the important meso-scales in geochemistry is the meso-timescale that is characteristic of processes too slow to probe with light spectroscopy but too fast to probe macroscopically. Nuclear magnetic resonance (NMR) spectroscopy is one of the only analytical methods with dynamic sensitivity to motions with correlation times on the 10-9 to 1 s timescales and is thus a uniquely powerful probe of meso-timescale dynamic behavior. Here, we describe the results of several studies exploring the meso-timescale motion of ions and H2O at the mineral-H2O interface of hectorite, a smectite clay mineral.1-3 2H, 23Na, 39K and 43Ca NMR results show that H2O molecules associated with the interface undergo anisotropic reorientation due to proximity to the surface and surface-associated cations. This motion can be described by rotational diffusion of the H2O molecule about its C2 symmetry axis at GHz frequencies combined with hopping of the H2O molecule about the normal to the smectite surface at ~>200 kHz. This model describes well the observed 2H NMR spectra of Na+, K+, and Ca2+ hectorites over a range temperatures between -80°C and 50°C, with the specific range dependent only on the total system H2O content. At temperatures above -20°C, systems with excess H2O with respect to a two-layer hydrate (low-H2O pastes through dilute aqueous suspensions) experience additional dynamic averaging due to H2O exchange between cation hydration shells, surface-sorbed species, and bulk inter-particle water. The extent of 2H averaging due to this exchange mechanism is strongly affected by the total H2O content in the system, the identity of the charge balancing cation, and the temperature. The dynamic averaging mechanisms affecting the cationic NMR resonances in these systems become dominated by diffusional processes at progressively lower temperatures as the hydration energy of the cation increases. These interfacial cation dynamics and binding sites are strongly affected by surface

  19. Cooling of Magnetars with Exotic Matter

    NASA Astrophysics Data System (ADS)

    Yasutake, Nobutoshi; Noda, Tsuneo; Fujisawa, Kotaro; Kotake, Kei; Shigeyama, Toshikazu

    Thermal evolutions of magnetars are studied concerned with effects of exotic matter. All results are shown in two spatial dimensions for comparison with observational results by NuSTAR, NICER etc. in near future. Thermal conduction of envelope/crust in magnetars is affected by the strong magnetic field, and it could be an origin of hot/cold spots, which are expressed well with the two black body fitting. This study also stresses effects of the equation of state, on which the cooling processes, the thermal conductivity, and the heat capacity strongly depend. Exotic matter changes thermal evolutions of magnetars drastically, hence the effects could be detected in observations.

  20. Hyperfine field at Mn in the intermetallic compound LaMnSi2 measured by PAC using 111Cd nuclear probe

    NASA Astrophysics Data System (ADS)

    Domienikan, C.; Bosch-Santos, B.; Cabrera Pasca, G. A.; Saxena, R. N.; Carbonari, A. W.

    2015-04-01

    Magnetic hyperfine field at Mn site has been measured in the orthorhombic intermetallic compound LaMnSi2 with PAC spectroscopy using radioactive 111In- 111Cd nuclear probe. Samples of LaMnSi2 were prepared by melting pure metallic components in stoichiometric proportion in an arc furnace under argon atmosphere. The samples were sealed in a quartz tube under helium atmosphere, annealed at 1000 °C for 60 h and quenched in water. Samples were analyzed with X-ray diffraction method. 111In was introduced in the samples by thermal diffusion at 1000 °C for 60 h. PAC measurements were carried out with a six BaF2 detector spectrometer at several temperatures between 50 K and 410 K. Results show well defined quadrupole and magnetic interactions at all temperatures. The magnetic hyperfine field (Bhf) measured at 50 K is 7.1(1) T. The temperature dependence of Bhf follows the normal Brillouin-like behavior expected for a simple ferromagnetic ordering. The ferromagnetic transition temperature (Tc) was determined to be 401(1) K.

  1. Diamagnetic nuclear {sup 119}Sn probes in the copper chromites CuCr{sub 2}X{sub 4} (X = O, S, Se) with a spinel structure

    SciTech Connect

    Dmitrieva, T. V.; Lyubutin, I. S. Stepin, A. S.; Dubinskaya, Yu. L.; Smirnovskaya, E. M.; Berry, F. J.; Thomas, M. F.

    2007-04-15

    The CuCr{sub 2}X{sub 4} (X = O, S, Se) spinel system has been studied by the Moessbauer spectroscopy of the nuclear diamagnetic {sup 119}Sn probe at low temperatures in an external magnetic field. The hyperfine magnetic fields H{sup Sn} induced by paramagnetic ions at tin nuclei in the CuCr{sub 2}S{sub 4} and CuCr{sub 2}Se{sub 4} chalcogenides have giant values and are somewhat higher than those detected in the CuCr{sub 2}O{sub 4} oxide. This behavior is caused by the strong covalence of the chalcogenides, which is supported by the experimentally found isomer shifts. The H{sup Sn} field is found to be mainly contributed by superexchange 90{sup o} interactions in the B-sublattice along the Cr[B]-X-Sn[B] bond chain, whose role increases in the series O-S-Se. In the oxygen CuCr{sub 2}O{sub 4} spinel, the partial contributions to the H{sup Sn} field induced by the Cu{sup 2+} and Cr{sup 3+} ions are estimated. The local magnetic structure of the CuCr{sub 2}O{sub 4} spinel is refined, and its total magnetization is shown to be directed along the magnetic moment of copper in the A sublattice.

  2. Diamagnetic nuclear 119Sn probes in the copper chromites CuCr2X4 (X = O, S, Se) with a spinel structure

    NASA Astrophysics Data System (ADS)

    Dmitrieva, T. V.; Lyubutin, I. S.; Stepin, A. S.; Dubinskaya, Yu. L.; Smirnovskaya, E. M.; Berry, F. J.; Thomas, M. F.

    2007-04-01

    The CuCr2X4 (X = O, S, Se) spinel system has been studied by the Mössbauer spectroscopy of the nuclear diamagnetic 119Sn probe at low temperatures in an external magnetic field. The hyperfine magnetic fields H Sn induced by paramagnetic ions at tin nuclei in the CuCr2S4 and CuCr2Se4 chalcogenides have giant values and are somewhat higher than those detected in the CuCr2O4 oxide. This behavior is caused by the strong covalence of the chalcogenides, which is supported by the experimentally found isomer shifts. The H Sn field is found to be mainly contributed by superexchange 90° interactions in the B-sublattice along the Cr[B]-X-Sn[B] bond chain, whose role increases in the series O-S-Se. In the oxygen CuCr2O4 spinel, the partial contributions to the H Sn field induced by the Cu2+ and Cr3+ ions are estimated. The local magnetic structure of the CuCr2O4 spinel is refined, and its total magnetization is shown to be directed along the magnetic moment of copper in the A sublattice.

  3. Detnex Project: Dispersion, Structure and Tracking of Exotic Nuclei

    NASA Astrophysics Data System (ADS)

    Alvarez, M. A. G.; Gómez-Camacho, J.; Espino, J. M.; Mukha, I.; Martel, I.

    2007-05-01

    Since 1970's when double-folding model, based on M3Y interaction, had to be renormalized to fit the elastic scattering of weakly bound 6,7Li and 9Be nuclei, we learned that preconceptions based on the highly successful experience of the optical model on stable nuclei could not be simply extrapolated to the scattering of exotic nuclei. Recently, we have shown some evidences of long range mechanisms in 6He induced reactions that lead to the loss of flux in the elastic channel at kinematic conditions that suggest the nuclei are well beyond the strong absorption radius [O. R. Kakuee, M. A. G. Alvarez, M. V. Andrés, S. Cherubini, T. Davinson, A. Di Pietro, W. Galster, J. Gómez-Camacho, A. M. Laird, M. Lamehi-Rachti, I. Martel, A. M. Moro, J. Rahighi, A. M. Sánchez-Benitez, A. C. Shotter, W. B. Smith, J. Vervier, P. J. Woods. Nucl. Phys. A 765, (2006) 294]. Even so, the use of nuclear reactions as an spectroscopic tool to investigate the nuclear structure of weakly bound nuclei requires a deep understanding of the reactions induced by these nuclei. Therefore, precise experimental measurements of the elastic scattering of exotic nuclei on a variety of targets, as well as the measurements of the main reaction channels are required in order to converge experimentally and theoretically to this understanding. With this aim a campaign of experiments involving different institutions and collaborations is being carefully established and going ahead at several radioactive ion beam (RIB) facilities: ISOLDE (CERN), CRC (Be), GSI (Ge) and TRIUMPH (Ca). The main idea is to measure the scattering of He, Li, and Be isotopes, and perform an intensive theoretical treatment, besides promoting some necessary instrumental development. In particular we participate in the low energy branch of the FAIR project where we take part in the tracking studies and developments.

  4. Phenology of cheatgrass and associated exotic weeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cheatgrass (Bromus tectorum), is an exotic, highly invasive annual grass that has dramatically changed the aspect and ecological functions of vast areas of formerly big sagebrush/bunchgrass and salt desert rangelands in the Intermountain west. Cheatgrass increases the chance of ignition, rate of spr...

  5. Eye Removal Surgeries in Exotic Pets.

    PubMed

    Diehl, Kathryn A; McKinnon, Jo-Ann

    2016-01-01

    This article covers considerations and techniques of eye removal surgeries in exotic pets. After issues including surgical indications, anesthesia, patient preparation, and instrumentation are explored, surgical techniques are described. Enucleation/exenteration and modified evisceration are discussed, with species-specific nuances of small mammals, birds, reptiles, snakes, amphibians, and fish highlighted.

  6. Exotic Gauge Bosons in the 331 Model

    SciTech Connect

    Romero, D.; Ravinez, O.; Diaz, H.; Reyes, J.

    2009-04-30

    We analize the bosonic sector of the 331 model which contains exotic leptons, quarks and bosons (E,J,U,V) in order to satisfy the weak gauge SU(3){sub L} invariance. We develop the Feynman rules of the entire kinetic bosonic sector which will let us to compute some of the Z(0)' decays modes.

  7. Soil biota and exotic plant invasion.

    PubMed

    Callaway, Ragan M; Thelen, Giles C; Rodriguez, Alex; Holben, William E

    2004-02-19

    Invasive plants are an economic problem and a threat to the conservation of natural systems. Escape from natural enemies might contribute to successful invasion, with most work emphasizing the role of insect herbivores; however, microbial pathogens are attracting increased attention. Soil biota in some invaded ecosystems may promote 'exotic' invasion, and plant-soil feedback processes are also important. Thus, relatively rare species native to North America consistently demonstrate negative feedbacks with soil microbes that promote biological diversity, whereas abundant exotic and native species demonstrate positive feedbacks that reduce biological diversity. Here we report that soil microbes from the home range of the invasive exotic plant Centaurea maculosa L. have stronger inhibitory effects on its growth than soil microbes from where the weed has invaded in North America. Centaurea and soil microbes participate in different plant-soil feedback processes at home compared with outside Centaurea's home range. In native European soils, Centaurea cultivates soil biota with increasingly negative effects on the weed's growth, possibly leading to its control. But in soils from North America, Centaurea cultivates soil biota with increasingly positive effects on itself, which may contribute to the success of this exotic species in North America.

  8. New Experiments with Stored Exotic Nuclei at the FRS-ESR Facility

    SciTech Connect

    Geissel, H.

    2009-08-26

    High accuracy mass and novel nuclear lifetime measurements have been performed with bare and few-electron ions produced via projectile fragmentation and fission, separated in flight and stored at relativistic energies. Characteristic experimental results and new developments are reviewed. A new generation of studies with exotic nuclei will be possible with the advent of the proposed international Facility for Antiproton and Ion Research (FAIR)

  9. Exotic annual grass alters fuel amounts, continuity and moisture content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Invasion by exotic plants are one of the most serious threats to native plant communities, biodiversity, and ecosystem functioning. Of particular concern are exotic plants that alter disturbance regimes. Exotic annual grasses are believed to increase wildfire frequency to the detriment of nativ...

  10. Estimating exotic gene flow into native pine stands: zygotic vs. gametic components.

    PubMed

    Unger, G M; Vendramin, G G; Robledo-Arnuncio, J J

    2014-11-01

    Monitoring contemporary gene flow from widespread exotic plantations is becoming an important problem in forest conservation genetics. In plants, where both seed and pollen disperse, three components of exotic gene flow with potentially unequal consequences should be, but have not been, explicitly distinguished: zygotic, male gametic and female gametic. Building on a previous model for estimating contemporary rates of zygotic and male gametic gene flow among plant populations, we present here an approach that additionally estimates the third (female gametic) gene flow component, based on a combination of uni- and biparentally inherited markers. Using this method and a combined set of chloroplast and nuclear microsatellites, we estimate gene flow rates from exotic plantations into two Iberian relict stands of maritime pine (Pinus pinaster) and Scots pine (Pinus sylvestris). Results show neither zygotic nor female gametic gene flow but moderate (6-8%) male gametic introgression for both species, implying significant dispersal of pollen, but not of seeds, from exotic plantations into native stands shortly after introduced trees reached reproductive maturity. Numerical simulation results suggest that the model yields reasonably accurate estimates for our empirical data sets, especially for larger samples. We discuss conservation management implications of observed levels of exposure to nonlocal genes and identify research needs to determine potentially associated hazards. Our approach should be useful for plant ecologists and ecosystem managers interested in the vectors of contemporary genetic connectivity among discrete plant populations.

  11. High-Sensitivity Nuclear Magnetic Resonance at Giga-Pascal Pressures: A New Tool for Probing Electronic and Chemical Properties of Condensed Matter under Extreme Conditions

    PubMed Central

    Meier, Thomas; Haase, Jürgen

    2014-01-01

    Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their electronic properties. The application of high pressure enables one to synthesize new materials, but the response of known materials to high pressure is a very useful tool for studying their electronic structure and developing theories. For example, high-pressure synthesis might be at the origin of life; and understanding the behavior of small molecules under extreme pressure will tell us more about fundamental processes in our universe. It is no wonder that there has always been great interest in having NMR available at high pressures. Unfortunately, the desired pressures are often well into the Giga-Pascal (GPa) range and require special anvil cell devices where only very small, secluded volumes are available. This has restricted the use of NMR almost entirely in the past, and only recently, a new approach to high-sensitivity GPa NMR, which has a resonating micro-coil inside the sample chamber, was put forward. This approach enables us to achieve high sensitivity with experiments that bring the power of NMR to Giga-Pascal pressure condensed matter research. First applications, the detection of a topological electronic transition in ordinary aluminum metal and the closing of the pseudo-gap in high-temperature superconductivity, show the power of such an approach. Meanwhile, the range of achievable pressures was increased tremendously with a new generation of anvil cells (up to 10.1 GPa), that fit standard-bore NMR magnets. This approach might become a new, important tool for the investigation of many condensed matter systems, in chemistry, geochemistry, and in physics, since we can now watch structural changes with the eyes of a very versatile probe. PMID:25350694

  12. High-sensitivity nuclear magnetic resonance at Giga-Pascal pressures: a new tool for probing electronic and chemical properties of condensed matter under extreme conditions.

    PubMed

    Meier, Thomas; Haase, Jürgen

    2014-10-10

    Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their electronic properties. The application of high pressure enables one to synthesize new materials, but the response of known materials to high pressure is a very useful tool for studying their electronic structure and developing theories. For example, high-pressure synthesis might be at the origin of life; and understanding the behavior of small molecules under extreme pressure will tell us more about fundamental processes in our universe. It is no wonder that there has always been great interest in having NMR available at high pressures. Unfortunately, the desired pressures are often well into the Giga-Pascal (GPa) range and require special anvil cell devices where only very small, secluded volumes are available. This has restricted the use of NMR almost entirely in the past, and only recently, a new approach to high-sensitivity GPa NMR, which has a resonating micro-coil inside the sample chamber, was put forward. This approach enables us to achieve high sensitivity with experiments that bring the power of NMR to Giga-Pascal pressure condensed matter research. First applications, the detection of a topological electronic transition in ordinary aluminum metal and the closing of the pseudo-gap in high-temperature superconductivity, show the power of such an approach. Meanwhile, the range of achievable pressures was increased tremendously with a new generation of anvil cells (up to 10.1 GPa), that fit standard-bore NMR magnets. This approach might become a new, important tool for the investigation of many condensed matter systems, in chemistry, geochemistry, and in physics, since we can now watch structural changes with the eyes of a very versatile probe.

  13. Accuracy of Reaction Cross Section for Exotic Nuclei in Glauber Model Based on MCMC Diagnostics

    NASA Astrophysics Data System (ADS)

    Rueter, Keiti; Novikov, Ivan

    2017-01-01

    Parameters of a nuclear density distribution for an exotic nuclei with halo or skin structures can be determined from the experimentally measured reaction cross-section. In the presented work, to extract parameters such as nuclear size information for a halo and core, we compare experimental data on reaction cross-sections with values obtained using expressions of the Glauber Model. These calculations are performed using a Markov Chain Monte Carlo algorithm. We discuss the accuracy of the Monte Carlo approach and its dependence on k*, the power law turnover point in the discreet power spectrum of the random number sequence and on the lag-1 autocorrelation time of the random number sequence.

  14. Cercarial Dermatitis Transmitted by Exotic Marine Snail

    PubMed Central

    Cohen, Andrew N.; James, David; Hui, Lucia; Hom, Albert; Loker, Eric S.

    2010-01-01

    Cercarial dermatitis (swimmer’s itch) is caused by the penetration of human skin by cercariae of schistosome parasites that develop in and are released from snail hosts. Cercarial dermatitis is frequently acquired in freshwater habitats, and less commonly in marine or estuarine waters. To investigate reports of a dermatitis outbreak in San Francisco Bay, California, we surveyed local snails for schistosome infections during 2005–2008. We found schistosomes only in Haminoea japonica, an Asian snail first reported in San Francisco Bay in 1999. Genetic markers place this schistosome within a large clade of avian schistosomes, but do not match any species for which there are genetic data. It is the second known schistosome species to cause dermatitis in western North American coastal waters; these species are transmitted by exotic snails. Introduction of exotic hosts can support unexpected emergence of an unknown parasite with serious medical or veterinary implications. PMID:20735918

  15. Nuclear Probing of Dense Plasmas

    SciTech Connect

    Richard Petrasso

    2007-02-14

    The object of inertial confinement fusion (ICF) is to compress a fuel capsule to a state with high enough density and temperature to ignite, starting a self-sustaining fusion burn that consumes much of the fuel and releases a large amount of energy. The national ICF research program is trying to reach this goal, especially through experiments at the OMEGA laser facility of the University of Rochester Laboratory of Laser Energetics (LLE), planned experiments at the National Ignition Facility (NIF) under construction at the Lawrence Livermore National Laboratory (LLNL), and experimental and theoretical work at other national laboratories. The work by MIT reported here has played several important roles in this national program. First, the development of new and improved charged-particle-based plasma diagnostics has allowed the gathering of new and unique diagnostic information about the implosions of fuel capsules in ICF experiments, providing new means for evaluating experiments and for studying capsule implosion dynamics. Proton spectrometers have become the standard for evaluating the mass assembly in compressed capsules in experiments at OMEGA; the measured energy downshift of either primary or secondary D3He fusion protons to determines the areal density, or ?R, of imploded capsules. The Proton Temporal Diagnostic measures the time history of fusion burn, and multiple proton emission imaging cameras reveal the 3-D spatial distribution of fusion burn. A new compact neutron spectrometer, for measuring fusion yield, is described here for the first time. And of especially high importance to future work is the Magnetic Recoil Spectrometer (MRS), which is a neutron spectrometer that will be used to study a range of important performance parameters in future experiments at the NIF. A prototype is currently being prepared for testing at OMEGA, using a magnet funded by this grant. Second, MIT has used these diagnostic instruments to perform its own physics experiments and analysis with implosions at OMEGA, to provide essential data to other experimenters at LLE, and to work collaboratively with researchers from all the national laboratories (including LLNL, Los Alamos National Laboratory, and Sandia National Laboratory). Some of the implosion dynamics physics studies reported here involve the relationships between drive asymmetries and implosion asymmetries (in terms of both mass assembly and fusion burn); the time evolution of mass assembly and mass asymmetries; the behavior of shock coalescence; and the nature of fuel-shell mix. Third, the MIT program has provided unique educational and research opportunities for both graduate and undergraduate students. The graduate students are deeply engaged in every aspect of our research program, and spend considerable time at OMEGA working on experiments and working with our collaborators from OMEGA and from the National Labs. Many undergraduates have gotten a taste of ICF research, sometimes making significant contributions. We believe that the introduction of energetic and gifted students to the challenging problems of this field and the excitement of the national lab environment leads naturally to the infusion of bright, talented young scientists into our field, and several PhD recipients from this group have become important forces in the field. Finally, this work has provided the foundation for continuing advances during upcoming research, with other experimental and theoretical studies of implosion dynamics. In addition to the continuing application of diagnostic instrumentation used during this grant, important contributions will be made with new diagnostics such as the MRS and with new techniques based on the knowledge obtained here, such as proton radiography.

  16. Legal implications of the exotic pet practice.

    PubMed

    Maas, Adolf K

    2005-09-01

    The ever-growing complexity of veterinary laws compounds the problem for the exotic pet practice. Issues of possession, treatment, vaccination, and ethics shape the legal landscape for the veterinarian, and as new problems develop, new legislation will be created. Only by learning and understanding the current laws and regulations of the jurisdiction can a practitioner hope to keep abreast of the changes and additions as they occur and to minimize the risk of liability.

  17. Exotic Rotational Correlations in Quantum Geometry

    SciTech Connect

    Hogan, Craig

    2015-09-26

    It is argued by extrapolation of general relativity and quantum mechanics that a classical inertial frame corresponds to a statistically defined observable that rotationally fluctuates due to Planck scale indeterminacy. Physical effects of exotic nonlocal rotational correlations on large scale field states are estimated. Their entanglement with the strong interaction vacuum is estimated to produce a universal, statistical centrifugal acceleration that resembles the observed cosmological constant.

  18. Exotic Forms of Silicon for Energy Applications

    NASA Astrophysics Data System (ADS)

    Taylor, P. Craig

    2015-03-01

    Over the last few decades many exotic forms of carbon, such as carbon-60, carbon nanotubes, and graphene, have generated novel scientific discoveries and revolutionized many important applications. Similar potentially transformative breakthroughs may be expected with exotic forms of silicon. Such structures include, but are not necessarily limited to, (1) those formed under high pressure that are metastable at ambient pressure, (2) single layers of Si (silicene), (2) clathrate Si, which has been studied for superconducting and thermoelectric properties but not in any detail for semiconductor applications, (3) nanostructured forms of Si (nanodots and nanowires), including those composed of diamond Si, (4) porous Si, and (5) any other structures that differ in their structural, optical or electronic properties from bulk diamond Si. Silicon is an abundant, non-toxic element around which an advanced technology exists for semiconducting devices based on diamond Si. One of these exotic forms of Si could form the basis for the next revolution in electronics or even opto-electronics, since some forms exhibit direct, or nearly direct, band gaps. Recent results toward producing pure and dopable semiconductors out of Si nanodots imbedded in amorphous matrices and in clathrate Si and clathrate Si-Ge alloys will be discussed. The author acknowledges important collaborations with R. T. Collins, C. A. Koh, L. Krishna, M. Lusk, and P. Stradins. DOE SUNSHOT program, under Contract DE-EE0005326 and by the NSF MRSEC program under Grant DMR-0820518.

  19. Commissioned article: management of exotic snakebites.

    PubMed

    Warrell, D A

    2009-09-01

    Exotic (foreign or non-native) snakes, including venomous species, are becoming increasingly popular pets in Western countries. Some of them are kept illegally (as defined by the UK Dangerous Wild Animals Act of 1976). There is a large international market for such animals, with contraventions of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). In the UK, several other European countries and the USA the reported numbers of bites by venomous exotic snakes, although small, are increasing but still underestimate the occurrence of these occasionally fatal events because of the victims' reluctance to seek medical care. Victims are predominantly young men who have been drinking alcohol. Bites may be intentionally provoked. In Europe, the species most often involved are cobras, green mambas, American pit vipers particularly rattlesnakes, African adders, vipers and Asian green pit vipers. To illustrate the special problems involved, case histories are presented of bites by exotic species in the UK and of bites abroad, where patients were repatriated for treatment. In view of the relative rarity and diversity of these cases, expert advice must usually be sought. These requests should include information about the species thought to have been responsible and the history and timing of the evolution of envenoming. Sources of advice and antivenom are discussed together with recommendations for appropriate first aid and emergency treatment while this is being awaited. Respiratory and cardiovascular resuscitation may be required and when systemic or severe local envenoming develops, specific (equine or ovine) antivenom is indicated.

  20. Cosmological constraints on exotic injection of electromagnetic energy

    NASA Astrophysics Data System (ADS)

    Poulin, Vivian; Lesgourgues, Julien; Serpico, Pasquale D.

    2017-03-01

    We compute cosmic microwave background (CMB) anisotropy constraints on exotic forms of energy injection in electromagnetic (e.m.) channels over a large range of timescales. We show that these constraints are very powerful around or just after recombination, although CMB keeps some sensitivity e.g. to decaying species with lifetimes as long as 1025 s. These bounds are complementary to CMB spectral distortions and primordial nucleosynthesis ones, which dominate at earlier timescales, as we also review here. For the first time, we describe the effects of the e.m. energy injection on the CMB power spectra as a function of the injection epoch, using the lifetime of a decaying particle as proxy. We also identify a suitable on-the-spot approximation, that can be used to derive accurate constraints, and describe its differences with the most up-to-date treatment. Our results are of interest not only for early universe relics constituting (a fraction of) the dark matter, but also for other exotic injection of e.m. radiation. For illustration, we apply our formalism to: i) Primordial black holes of mass 1013.5 g lesssim M lesssim 1016.8 g, showing that the constraints are comparable to the ones obtained from gamma-ray background studies and even dominate below ~ 1014 g. ii) To a peculiar mass-mixing range in the sterile neutrino parameter space, complementary to other astrophysical and laboratory probes. iii) Finally, we provide a first estimate of the room for improvement left for forthcoming 21 cm experiments, comparing it with the reach of proposed CMB spectral distortion (PiXiE) and CMB angular power spectrum (CORE) missions. We show that the best and most realistic opportunity to look for this signal (or to improve over current constraints) in the 21 cm probe is to focus on the Cosmic Dawn epoch, 15 lesssim z lesssim 30, where the qualitatively unambiguous signature of a spectrum in emission can be expected for models that evade all current constraints.

  1. GDR as a Probe of the Collective Motion in Nuclei at High Spins, Temperatures or Isospins

    SciTech Connect

    Maj, Adam

    2008-11-11

    The gamma-decay of the Giant Dipole Resonance (GDR), the high-frequency collective vibration of protons against neutrons, has been proven to be a basic probe for the shapes of hot nuclei, especially to study the effective shape evolution caused by the collective rotation of a nucleus. In this context an interesting question arises: what is the nuclear shape at extreme values of spin or temperatures, close to the limit impose by another collective motion--fission, and how evolves the giant dipole collective vibrations as a function of isospin. Short overview of the results from the experiments aimed to answer these questions are presented and possible perspectives of these type of studies for exotic nuclei to be obtained with the novel gamma-calorimeter PARIS and soon available intense radioactive beams are discussed.

  2. Metabolomics has great potential for clinical and nutritional care and research with exotic animals.

    PubMed

    Dove, Alistair D M

    2013-01-01

    This essay explores the potential of metabolomics for exotic animal research in a zoological setting. Metabolomics is a suite of analytical tools aimed at gaining a holistic understanding of animal metabolism without prior knowledge of the compounds to be measured. These metabolic fingerprints can be used to define normal metabolism for an unstudied species, to characterize the metabolic deviation of diseased animals from the normal state over time, to identify biomarker compounds that best capture such deviations, and to measure the metabolic impact of clinical and nutritional interventions. Two approaches, nuclear magnetic resonance (NMR) and mass spectrometry (MS) provide large amounts of complimentary pure and applied biological data. Metabolomic methods hold great potential for researchers, clinicians, and nutritionists studying exotic and aquatic animals because they can produce a huge data return on research effort, and because they do not require much a priori knowledge of the animals' metabolism, which is so often then case in zoological settings.

  3. TOF-Bρ mass measurements of very exotic nuclides for astrophysical calculations at the NSCL

    NASA Astrophysics Data System (ADS)

    Matoš, M.; Estrade, A.; Amthor, M.; Aprahamian, A.; Bazin, D.; Becerril, A.; Elliot, T.; Galaviz, D.; Gade, A.; Gupta, S.; Lorusso, G.; Montes, F.; Pereira, J.; Portillo, M.; Rogers, A. M.; Schatz, H.; Shapira, D.; Smith, E.; Stolz, A.; Wallace, M.

    2008-01-01

    Atomic masses play a crucial role in many nuclear astrophysics calculations. The lack of experimental values for relevant exotic nuclides triggered a rapid development of new mass measurement devices around the world. The time-of-flight (TOF) mass measurements offer a complementary technique to the most precise one, Penning trap measurements (Blaum 2006 Phys. Rep. 425 1), the latter being limited by the rate and half-lives of the ions of interest. The NSCL facility provides a well-suited infrastructure for the TOF mass measurements of very exotic nuclei. At this facility, we have recently implemented a TOF-Bρ technique and performed mass measurements of neutron-rich nuclides in the Fe region, important for r-process calculations and for calculations of processes occurring in the crust of accreting neutron stars.

  4. Role of the cluster deformations in explaining the exotic decay half-lives

    NASA Astrophysics Data System (ADS)

    Soylu, A.; Sert, Y.; Bayrak, O.; Boztosun, I.

    2012-09-01

    We investigate the influence of nuclear deformations of the cluster and daughter nuclei on the exotic cluster decay half-lives of ensuremath 221≤ A ≤ 242 for the favored cluster decay of the radioactive nuclei by using the semiclassical WKB method and the Bohr-Sommerfeld quantization condition. The results have also been presented for the spherical nuclei case in order to show clearly the effects of the deformations on the exotic decay half-lives. The half-lives become close to the experimental data when both the deformation of daughter and cluster nuclei are taken into account in the calculations. Furthermore, considering cluster deformations together with the orientation angles of daughter and cluster also provides positive contributions to the results.

  5. ENAM'04 Fourth International Conference on Exotic Nuclei and Atomic Masses

    SciTech Connect

    Gross, C. J.; Nazarewicz, W.; Rykaczewski, K. P.

    2005-01-01

    The conference can trace its origins to the 1950s and 1960s with the Atomic Mass and Fundamental Constants (AMCO) and the Nuclei Far From Stability (NFFS) series of conferences. Held jointly in 1992, the conferences officially merged in 1995 and the fourth conference was held at Callaway Gardens in Pine Mountain, GA and was organized by the Physics Division at Oak Ridge National Laboratory. The conference covered a broad list of topics consisting of a series of invited and contributed presentation highlighting recent research in the following fields: Atomic masses, nuclear moments, and nuclear radii; Forms of radioactivity; Nuclear structure, nuclei at the drip lines, cluster phenomena; Reactions with radioactive ion beams; Nuclear astrophysics; Fundamental symmetries and interactions; Heaviest elements and fission; Radioactive ion beam production and experimental developments; Applications of exotic nuclei

  6. Probing the formation and evolution of comets via nuclear spin temperatures of C_2H_6, CH_3OH, CH_4, NH_3, and H_2O

    NASA Astrophysics Data System (ADS)

    Villanueva, G.; Mumma, M.; Bonev, B.; DiSanti, M.; Paganini, L.; Magee-Sauer, K.; Gibb, E.

    2014-07-01

    Comets are true remnants of our primordial Solar System, and provide unique clues to its formation and evolution, including the delivery of organics and water to our planet. A key indicator stored in the molecular structure of the nuclear ices is the spin temperature (T_{spin}), derived from spin-isomeric ratios (R_{spin}, e.g., ortho/para). At the time when cometary ices formed, the prevailing temperature defined the relative abundance of the different spin-isomeric species, and herewith R_{spin} and T_{spin} are normally treated as ''remnant thermometers'' probing the formation environments of cometary molecules. Radiative and collisional transitions between the ortho and para states are strongly forbidden and herewith this indicator is preserved over time. Most of our knowledge of this indicator comes from the measurements of the ortho-para ratios in water and NH_2 (a proxy for ammonia), suggesting a common T_{spin} near 30 K. This information is based on a restricted sample of comets, and the measurements are particularly sensitive to the molecular modeling technique and adopted spectral database. Here, we present new methodologies for extracting spin temperatures from ethane (C_2H_6), methane (CH_4), and methanol (CH_3OH), and advanced new models for ortho/para water (H_2O) and ammonia (NH_3). Our H_2O analysis is based on the most complete fluorescence radiative-transfer model to date, which incorporates 1,200 million transitions including those originating from high-energy levels that are activated in comets via a non-resonant cascade. In a similar fashion, we developed non-resonant fluorescence models for NH_3 and HCN, and quantum-band models for the ν_7 band of C_2H_6 and ν_3 band of CH_3OH. All models respect spin-symmetry non-conversion radiative rules, and make use of a realistic solar spectrum for the computation of fluorescence pumps. We applied these new methods to derive spin-isomeric ratios for H_2O, CH_4, C_2H_6, CH_3OH, and NH_3 from three high

  7. Contribution of atom-probe tomography to a better understanding of glass alteration mechanisms: Application to a nuclear glass specimen altered 25 years in a granitic environment

    SciTech Connect

    Gin, Stephane; Ryan, Joseph V.; Schreiber, Daniel K.; Neeway, James J.; Cabie, M.

    2013-04-08

    Here, we report and discuss results of atom probe tomography (APT) and energy-filtered transmission electron microscopy (EFTEM) applied to a borosilicate glass sample of nuclear interest altered for nearly 26 years at 90°C in a confined granitic medium in order to better understand the rate-limiting mechanisms under conditions representative of a deep geological repository for vitrified radioactive waste. The APT technique allows the 3D reconstruction of the elemental distribution at the reactive interphase with sub-nanometer precision. Profiles of the B distribution at pristine glass/hydrated glass interface obtained by different techniques are compared to show the challenge of accurate measurements of diffusion profiles at this buried interface on the nanometer length scale. Our results show that 1) Alkali from the glass and hydrogen from the solution exhibit anti-correlated 15 ± 3 nm wide gradients located between the pristine glass and the hydrated glass layer, 2) boron exhibits an unexpectedly sharp profile located just at the outside of the alkali/H interdiffusion layer; this sharp profile is more consistent with a dissolution front than a diffusion-controlled release of boron. The resulting apparent diffusion coefficients derived from the Li and H profiles are DLi = 1.5 × 10-22 m2.s-1 and DH = 6.8 × 10-23 m2.s-1. These values are around two orders of magnitude lower than those observed at the very beginning of the alteration process, which suggests that interdiffusion is slowed at high reaction progress by local conditions that could be related to the porous structure of the interphase. As a result, the accessibility of water to the pristine glass could be the rate-limiting step in these conditions. More generally, these findings strongly support the importance of interdiffusion coupled with hydrolysis reactions of the silicate network on the long-term dissolution

  8. Contribution of atom-probe tomography to a better understanding of glass alteration mechanisms: Application to a nuclear glass specimen altered 25 years in a granitic environment

    DOE PAGES

    Gin, Stephane; Ryan, Joseph V.; Schreiber, Daniel K.; ...

    2013-04-08

    Here, we report and discuss results of atom probe tomography (APT) and energy-filtered transmission electron microscopy (EFTEM) applied to a borosilicate glass sample of nuclear interest altered for nearly 26 years at 90°C in a confined granitic medium in order to better understand the rate-limiting mechanisms under conditions representative of a deep geological repository for vitrified radioactive waste. The APT technique allows the 3D reconstruction of the elemental distribution at the reactive interphase with sub-nanometer precision. Profiles of the B distribution at pristine glass/hydrated glass interface obtained by different techniques are compared to show the challenge of accurate measurements ofmore » diffusion profiles at this buried interface on the nanometer length scale. Our results show that 1) Alkali from the glass and hydrogen from the solution exhibit anti-correlated 15 ± 3 nm wide gradients located between the pristine glass and the hydrated glass layer, 2) boron exhibits an unexpectedly sharp profile located just at the outside of the alkali/H interdiffusion layer; this sharp profile is more consistent with a dissolution front than a diffusion-controlled release of boron. The resulting apparent diffusion coefficients derived from the Li and H profiles are DLi = 1.5 × 10-22 m2.s-1 and DH = 6.8 × 10-23 m2.s-1. These values are around two orders of magnitude lower than those observed at the very beginning of the alteration process, which suggests that interdiffusion is slowed at high reaction progress by local conditions that could be related to the porous structure of the interphase. As a result, the accessibility of water to the pristine glass could be the rate-limiting step in these conditions. More generally, these findings strongly support the importance of interdiffusion coupled with hydrolysis reactions of the silicate network on the long-term dissolution rate, contrary to what has been suggested by recent interfacial dissolution

  9. Learning Nuclear Science with Marbles

    ERIC Educational Resources Information Center

    Constan, Zach

    2010-01-01

    Nuclei are "small": if an atom was the size of a football field, the nucleus would be an apple sitting on the 50-yd line. At the same time, nuclei are "dense": the Earth, compressed to nuclear density, could fit inside four Sears Towers. The subatomic level is strange and exotic. For that reason, it's not hard to get young minds excited about…

  10. Global analysis of fermion mixing with exotics

    NASA Technical Reports Server (NTRS)

    Nardi, Enrico; Roulet, Esteban; Tommasini, Daniele

    1991-01-01

    The limits are analyzed on deviation of the lepton and quark weak-couplings from their standard model values in a general class of models where the known fermions are allowed to mix with new heavy particles with exotic SU(2) x U(1) quantum number assignments (left-handed singlets or right-handed doublets). These mixings appear in many extensions of the electroweak theory such as models with mirror fermions, E(sub 6) models, etc. The results update previous analyses and improve considerably the existing bounds.

  11. Rare and exotic processes at CDF

    SciTech Connect

    Culbertson, Ray; /Fermilab

    2010-01-01

    We report recent results in CDF searches for rare and exotic processes. In a signature-based search, we examine the diphoton dataset for additional energetic objects. In a second signature-based search, we search for anomalous production of a photon, a b-tagged jet, and missing E{sub T}. Finally, we search for a Fermiophobic Higgs in the two-photon decay mode, and conclude this Higgs must have mass greater than 106 GeV/c{sup 2}, at 95% confidence level.

  12. Monitoring two native Spodoptera species using an exotic pheromone lure developed for an exotic species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pheromone lure for the exotic species Spodoptera exempta was successful at attracting two native species, S. latifascia and S. albula. Trapping was conducted in north-central Florida and in southern Texas. Large numbers of both native species were collected throughout the season....

  13. Linking economic activities to the distribution of exotic plants.

    PubMed

    Taylor, Brad W; Irwin, Rebecca E

    2004-12-21

    The human enterprise is flooding Earth's ecosystems with exotic species. Human population size is often correlated with species introductions, whereas more proximate mechanisms, such as economic activities, are frequently overlooked. Here we present a hypothesis that links ecology and economics to provide a causal framework for the distribution of exotic plants in the United States. We test two competing hypotheses (the population-only and population-economic models) using a national data set of exotic plants, employing a statistical framework to simultaneously model direct and indirect effects of human population and ecological and economic variables. The population-only model included direct effects of human population and ecological factors as predictors of exotics. In contrast, the population-economic model included the direct effects of economic and ecological factors and the indirect effects of human population as predictors of exotics. The explicit addition of economic activity in the population-economic model provided a better explanation for the distribution of exotics than did the population-only model. The population-economic model explained 75% of the variation in the number of exotic plants in the 50 states and provided a good description of the observed number of exotic plants in the Canadian provinces and in other nations in 85% of the cases. A specific economic activity, real estate gross state product, had the strongest positive effect on the number of exotics. The strong influence of economics on exotics demonstrates that economics matter for resolving the exotic-species problem because the underlying causes, and some of the solutions, may lie in human-economic behaviors.

  14. ICENES '91:Sixth international conference on emerging nuclear energy systems

    SciTech Connect

    Not Available

    1991-01-01

    This document contains the program and abstracts of the sessions at the Sixth International Conference on Emerging Nuclear Energy Systems held June 16--21, 1991 at Monterey, California. These sessions included: The plenary session, fission session, fission and nonelectric session, poster session 1P; (space propulsion, space nuclear power, electrostatic confined fusion, fusion miscellaneous, inertial confinement fusion, [mu]-catalyzed fusion, and cold fusion); Advanced fusion session, space nuclear session, poster session 2P, (nuclear reactions/data, isotope separation, direct energy conversion and exotic concepts, fusion-fission hybrids, nuclear desalting, accelerator waste-transmutation, and fusion-based chemical recycling); energy policy session, poster session 3P (energy policy, magnetic fusion reactors, fission reactors, magnetically insulated inertial fusion, and nuclear explosives for power generation); exotic energy storage and conversion session; and exotic energy storage and conversion; review and closing session.

  15. Exotic meson production in BNL experiment E852

    NASA Astrophysics Data System (ADS)

    Adams, G. S.; Adams, T.; Bar-Yam, Z.; Bishop, J. M.; Bodyagin, V. A.; Brown, D. S.; Cason, N. M.; Chasse, M.; Chung, S. U.; Cummings, J. P.; Danyo, K.; Demianov, A. I.; Denisov, S. P.; Dorofeev, V.; Dowd, J. P.; Eugenio, P.; Fan, X. L.; Gribushin, A. M.; Hackenburg, R. W.; Hayek, M.; Hu, J.; Ivanov, E. I.; Joffe, D.; Kachaev, I.; Kern, W.; King, E.; Kodolova, O. L.; Korotkikh, V. L.; Kostin, M. A.; Krenkel, J.; Kuhn, J.; Lipaev, V. V.; Lo Secco, J. M.; Lu, M.; Manak, J. J.; Nozar, M.; Olchanski, C.; Ostrovidov, A. I.; Pedlar, T. K.; Popov, A. V.; Ryabchikov, D. I.; Sarycheva, L. I.; Seth, K. K.; Shenhav, N.; Shen, X.; Shephard, W. D.; Sinev, N. B.; Stienike, D. L.; Suh, J. S.; Taegar, S. A.; Tomaradze, A.; Vardanyan, I. N.; Weygand, D. P.; White, D. B.; Willutzki, H. J.; Witkowski, M.; Yershov, A. A.

    2005-01-01

    The status of spin-exotic mesons is reviewed. There is now compelling evidence for at least three π1 states between one and two GeV. Preliminary results from the reaction π-p → π+π+π-π-π0p show structure in the exotic waves corresponding to IGJPC = 0-2+-.

  16. Education and Feminist Aesthetics: Gauguin and the Exotic

    ERIC Educational Resources Information Center

    Duran, Jane

    2009-01-01

    Throughout this article, the author argued that the attraction of the "exotic" for Gauguin was largely revealed by his response to the women of various locales and that two notions--that of the "feminine" and the "foreign" or exotic--became intertwined for him. She relied both upon the commentary of Britt Salvesen with respect to Gauguin's obvious…

  17. Application of laser technology to exotic veterinary practice

    NASA Astrophysics Data System (ADS)

    Clipsham, Robert C.

    1993-07-01

    Exotic veterinary practice has evolved in connection with the importation industry, development of zoological collections and rising private pet ownership to the point that laser technology is in demand. The specific needs of the many species presented for surgical care and the expectations of owners are examined in relationship to the currently understood diseases of exotic animals.

  18. Resources for Teaching and Learning about Exotic Species. ERIC Digest.

    ERIC Educational Resources Information Center

    Lee, Hyonyong; Fortner, Rosanne W.

    Exotic species are organisms transported by humans, wildlife, wind, and water into regions where they did not historically exist. This ERIC Digest describes available materials and resources for teaching and learning about these exotic species. Sixteen Internet sources are provided along with six videotape resources. The digest also provides…

  19. A Theory of Island Biogeography for Exotic Species.

    PubMed

    Burns, Kevin C

    2015-10-01

    The theory of island biogeography has played a pivotal role in the way ecologists view communities. However, it does not account for exotic species explicitly, which limits its use as a conservation tool. Here, I present the results of a long-term study of plant communities inhabiting an archipelago of small islands off the coast of New Zealand and derive a modified version of the theory of island biogeography to predict differences in the turnover and diversity of native and exotic species. Empirical results showed that, although species richness of both native and exotic plant species increased with island area, native species consistently outnumbered exotic species. Species turnover increased with species richness in both groups. However, opposite to species-area patterns, turnover increased more rapidly with species richness in exotic species. Empirical results were consistent with the modified version of the theory of island biogeography, which distinguishes exotic species from native species by decoupling extinction rates of exotic species from island area, because they are represented by only small populations at the initial stages of invasion. Overall results illustrate how the theory of island biogeography can be modified to reflect the dynamics of exotic species as they invade archipelagos, expanding its use as a conservation tool.

  20. The quest for novel modes of excitation in exotic nuclei

    NASA Astrophysics Data System (ADS)

    Paar, N.

    2010-06-01

    This paper provides an insight into several open problems in the quest for novel modes of excitation in nuclei with isospin asymmetry, deformation and finite-temperature characteristics in stellar environments. Major unsolved problems include the nature of pygmy dipole resonances, the quest for various multipole and spin-isospin excitations both in neutron-rich and proton drip-line nuclei mainly driven by loosely bound nucleons, excitations in unstable deformed nuclei and evolution of their properties with the shape phase transition. Exotic modes of excitation in nuclei at finite temperatures characteristic of supernova evolution present open problems with a possible impact in modeling astrophysically relevant weak interaction rates. All these issues challenge self-consistent many-body theory frameworks at the frontiers of on-going research, including nuclear energy density functionals, both phenomenological and constrained by the strong interaction physics of QCD, models based on low-momentum two-nucleon interaction Vlow-k and correlated realistic nucleon-nucleon interaction VUCOM, supplemented by three-body force, as well as two-nucleon and three-nucleon interactions derived from the chiral effective field theory. Joined theoretical and experimental efforts, including research with radioactive isotope beams, are needed to provide insight into dynamical properties of nuclei away from the valley of stability, involving the interplay of isospin asymmetry, deformation and finite temperature.

  1. Transport Properties in Nuclear Pasta

    NASA Astrophysics Data System (ADS)

    Caplan, Matthew; Horowitz, Charles; Berry, Donald; da Silva Schneider, Andre

    2016-09-01

    At the base of the inner crust of neutron stars, where matter is near the nuclear saturation density, nuclear matter arranges itself into exotic shapes such as cylinders and slabs, called `nuclear pasta.' Lepton scattering from these structures may govern the transport properties of the inner crust; electron scattering from protons in the pasta determines the thermal and electrical conductivity, as well as the shear viscosity of the inner crust. These properties may vary in pasta structures which form at various densities, temperatures, and proton fractions. In this talk, we report on our calculations of lepton transport in nuclear pasta and the implication for neutron star observables.

  2. Hyperfine structure in 229gTh3+ as a probe of the 229gTh→ 229mTh nuclear excitation energy.

    PubMed

    Beloy, K

    2014-02-14

    We identify a potential means to extract the 229gTh→ 229mTh nuclear excitation energy from precision microwave spectroscopy of the 5F(5/2,7/2) hyperfine manifolds in the ion 229gTh3+. The hyperfine interaction mixes this ground fine structure doublet with states of the nuclear isomer, introducing small but observable shifts to the hyperfine sublevels. We demonstrate how accurate atomic structure calculations may be combined with the measurement of the hyperfine intervals to quantify the effects of this mixing. Further knowledge of the magnetic dipole decay rate of the isomer, as recently reported, allows an indirect determination of the nuclear excitation energy.

  3. Skin diseases of rodents and small exotic mammals.

    PubMed

    Ellis, C; Mori, M

    2001-05-01

    Small exotic mammals and rodents are becoming popular pets in the United States. Like most other exotics, the popularity of these animals has vastly preceded the accumulation of practical husbandry and veterinary information available about them. Several dermatologic conditions have been described in most rodents and small exotic mammals; however, the practitioner can assume that more exist that have not yet been diagnosed or documented. It is not unreasonable to assume that rodents and small exotic mammals could be affected by many of the same dermatologic conditions well described in other animals. Veterinarians are encouraged always to apply the same diagnostic protocols used to work up skin problems in dogs and cats when presented with an exotic pet with a dermatologic disease.

  4. Investigation of the structure of light exotic nuclei by proton elastic scattering in inverse kinematics

    NASA Astrophysics Data System (ADS)

    Alkhazov, G. D.; Vorobyov, A. A.; Dobrovolsky, A. V.; Inglessi, A. G.; Korolev, G. A.; Khanzadeev, A. V.

    2015-05-01

    In order to study the spatial structure of exotic nuclei, it was proposed at the Petersburg Nuclear Physics Institute (PNPI) to measure the differential cross section for small-angle proton elastic scattering in inverse kinematics. Several experiments in beams of 0.7-GeV/nucleon exotic nuclei were performed at the heavy-ion accelerator facility of GSI (Gesellschaft für Schwerionenforschung, Darmstadt, Germany) by using the IKAR ionization spectrometer developed at PNPI. The IKAR ionization chamber filled with hydrogen at a pressure of 10 bar served simultaneously as a target and as a recoil-proton detector, which measured the recoil-proton energy. The beam-particle scattering angle was also measured. The results obtained for the cross sections in question were analyzed on the basis of the Glauber-Sitenko theory using phenomenological nuclear-density distributions with two free parameters. Nuclear-matter distributions and root-mean-square radii were found for the nuclei under investigation. The size of the halo in the 6He, 8He, 11Li, and 14Be nuclei was determined among other things. Information about neutron distributions in nuclei was deduced by combining the data obtained here with the known values of the radii of proton distributions. A sizable neutron skin was revealed in the 8Li, 9Li, and 12Be nuclei.

  5. Investigation of the structure of light exotic nuclei by proton elastic scattering in inverse kinematics

    SciTech Connect

    Alkhazov, G. D.; Vorobyov, A. A.; Dobrovolsky, A. V. Inglessi, A. G.; Korolev, G. A.; Khanzadeev, A. V.

    2015-05-15

    In order to study the spatial structure of exotic nuclei, it was proposed at the Petersburg Nuclear Physics Institute (PNPI) to measure the differential cross section for small-angle proton elastic scattering in inverse kinematics. Several experiments in beams of 0.7-GeV/nucleon exotic nuclei were performed at the heavy-ion accelerator facility of GSI (Gesellschaft für Schwerionenforschung, Darmstadt, Germany) by using the IKAR ionization spectrometer developed at PNPI. The IKAR ionization chamber filled with hydrogen at a pressure of 10 bar served simultaneously as a target and as a recoil-proton detector, which measured the recoil-proton energy. The beam-particle scattering angle was also measured. The results obtained for the cross sections in question were analyzed on the basis of the Glauber-Sitenko theory using phenomenological nuclear-density distributions with two free parameters. Nuclear-matter distributions and root-mean-square radii were found for the nuclei under investigation. The size of the halo in the {sup 6}He, {sup 8}He, {sup 11}Li, and {sup 14}Be nuclei was determined among other things. Information about neutron distributions in nuclei was deduced by combining the data obtained here with the known values of the radii of proton distributions. A sizable neutron skin was revealed in the {sup 8}Li, {sup 9}Li, and {sup 12}Be nuclei.

  6. Spectrophotometric probe

    DOEpatents

    Prather, W.S.; O'Rourke, P.E.

    1994-08-02

    A support structure is described bearing at least one probe for making spectrophotometric measurements of a fluid using a source of light and a spectrophotometer. The probe includes a housing with two optical fibers and a planoconvex lens. A sleeve bearing a mirror surrounds the housing. The lens is separated from the mirror by a fixed distance, defining an interior space for receiving a volume of the fluid sample. A plurality of throughholes extending through the sleeve communicate between the sample volume and the exterior of the probe, all but one hole bearing a screen. A protective jacket surrounds the probe. A hollow conduit bearing a tube is formed in the wall of the probe for venting any air in the interior space when fluid enters. The probe is held at an acute angle so the optic fibers carrying the light to and from the probe are not bent severely on emergence from the probe. 3 figs.

  7. Spectrophotometric probe

    DOEpatents

    Prather, William S.; O'Rourke, Patrick E.

    1994-01-01

    A support structure bearing at least one probe for making spectrophotometric measurements of a fluid using a source of light and a spectrophotometer. The probe includes a housing with two optical fibers and a planoconvex lens. A sleeve bearing a mirror surrounds the housing. The lens is separated from the mirror by a fixed distance, defining an interior space for receiving a volume of the fluid sample. A plurality of throughholes extending through the sleeve communicate between the sample volume and the exterior of the probe, all but one hole bearing a screen. A protective jacket surrounds the probe. A hollow conduit bearing a tube is formed in the wall of the probe for venting any air in the interior space when fluid enters. The probe is held at an acute angle so the optic fibers carrying the light to and from the probe are not bent severely on emergence from the probe.

  8. RIB in-flight production and the facility EXOTIC at LNL

    SciTech Connect

    Mazzocco, Marco

    2014-05-09

    The production of Radioactive Ion Beams (RIBs) via the In-Flight technique is reviewed. This separation method typically employs four main production mechanisms: (i) Projectile Fragmentation; (ii) Projectile Fission; (iii) Nuclear Fusion and (iv) Direct Processes in Inverse Kinematics. We will concentrate particularly on the last mechanism, the one used by the facility EXOTIC at the INFN-Laboratori Nazionali di Legnaro (LNL) for the production of light RIBs. An extensive description of the facility and a brief overview of the most recent scientific achievements with {sup 7}Be and {sup 17}F are given.

  9. Nuclear astrophysics experiments with stored, highly-charged ions at FRS-ESR at GSI

    SciTech Connect

    Scheidenberger, Christoph

    2010-08-12

    At the FRS-ESR complex of GSI a nuclear physics program with exotic nuclei has been established in last 18 years, which also addresses key questions and nuclear properties relevant in nuclear astrophysics. The paper summarizes production of exotic nuclei, lifetime studies of highly-charged ions, direct mass measurements and reactions at internal targets. A few comments on the analysis of two-body weak decays are given.

  10. 9 CFR 352.13 - Handling and disposal of condemned or other inedible exotic animal products at official exotic...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Handling and disposal of condemned or other inedible exotic animal products at official exotic animal establishments. 352.13 Section 352.13 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

  11. 9 CFR 352.13 - Handling and disposal of condemned or other inedible exotic animal products at official exotic...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Handling and disposal of condemned or other inedible exotic animal products at official exotic animal establishments. 352.13 Section 352.13 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

  12. 9 CFR 352.13 - Handling and disposal of condemned or other inedible exotic animal products at official exotic...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Handling and disposal of condemned or other inedible exotic animal products at official exotic animal establishments. 352.13 Section 352.13 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

  13. 9 CFR 352.13 - Handling and disposal of condemned or other inedible exotic animal products at official exotic...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Handling and disposal of condemned or other inedible exotic animal products at official exotic animal establishments. 352.13 Section 352.13 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

  14. 9 CFR 352.13 - Handling and disposal of condemned or other inedible exotic animal products at official exotic...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Handling and disposal of condemned or other inedible exotic animal products at official exotic animal establishments. 352.13 Section 352.13 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

  15. Study of Isoscalar Giant Resonances in Exotic Nuclei by Means of Inverse Reactions

    NASA Astrophysics Data System (ADS)

    Harakeh, M. N.

    2015-11-01

    Isoscalar giant resonances in exotic nuclei can be studied using inelastic alpha scattering in inverse kinematics. In particular, the compression modes, i.e. isoscalar giant monopole and dipole resonances, are very interesting because they can furnish information on the different terms of the nuclear incompressibility, especially if measured in long isotopic chains including nuclei far from the valley of stability. As beams of exotic nuclei have relatively low intensities thick targets have to be used in order to get a reasonable yield. However, this leads to degradation of the energy resolution and stops low-energy recoil particles. Two good alternatives exist. The first method is to use an active target, such as MAYA, which is a time-projection chamber and therefore can be used for detection of low-energy recoil particles. Furthermore, its thickness can be increased by increasing the length of the detection volume or the gas pressure without severe loss of energy resolution. The second method is to use a storage ring for storing the exotic nuclei, which then interact with target nuclei from a gas-jet target. Here, the luminosity and hence the yield are increased because the exotic nuclei circulate in the ring at a frequency of around 106 turns/s. Low-energy recoil particles traverse the gas-jet with little loss of energy and can be detected in solid-state detectors. Pioneering experiments with both methods have been performed for inelastic scattering of secondary 56Ni beam off helium nuclei. Here, preliminary results of the experiment with the active target MAYA will be presented.

  16. Controlling the exotic diseases: 1. Isolation facilities.

    PubMed Central

    Clayton, A J; Best, H R

    1980-01-01

    The exotic diseases are highly virulent transmissible conditions that include Lassa fever, some viral hemorrhagic fevers, smallpox and plague. Any of these diseases could be brought into or diagnosed in Canada as the result of natural or laboratory acquired infection. The patients must be isolated until the presumptive diagnosis is proved. High-security isolation is necessary and needs to be backed up by high-security laboratory services. In Canada facilities for high-security isolation are generally not available; therefore, hospitals must preplan and be ready to effect the best possible isolation under the existing conditions. The plan should address construction, ventilation, filtration, temperature and humidity, together with protective measures for staff and careful handling of laboratory specimens. Materials the patient has contacted and areas or vehicles he or she has been in will have to be decontaminated, and appropriate, safe disposal of corpses must be considered. PMID:7437989

  17. Exotic Photon Searches at CDF II

    SciTech Connect

    Lee, Eunsin; collaboration, for the CDF

    2009-10-01

    We present recent results of searches for exotic photons at CDF II. In the first signature-based search, we search for anomalous production of two photons with additional energetic objects. The results are consistent with the standard model expectations. In the second analysis, we present a signature-based search for anomalous production of events containing a photon, two jets, of which at least one is identified as originating from a b quark, and missing transverse energy. We find no indications of non-standard model phenomena. Finally, a search for a fermiophobic Higgs in the diphoton final state is presented. Since no evidence of a resonance in the diphoton mass spectrum is observed we exclude this Higgs boson with mass below 106 GeV/c{sup 2} at a 95% confidence level.

  18. Structure models: From shell model to ab initio methods. A brief introduction to microscopic theories for exotic nuclei

    NASA Astrophysics Data System (ADS)

    Bacca, Sonia

    2016-04-01

    A brief review of models to describe nuclear structure and reactions properties is presented, starting from the historical shell model picture and encompassing modern ab initio approaches. A selection of recent theoretical results on observables for exotic light and medium-mass nuclei is shown. Emphasis is given to the comparison with experiment and to what can be learned about three-body forces and continuum properties.

  19. The Exotic Exchange of Smoke Rings

    NASA Astrophysics Data System (ADS)

    Niemi, A. J.

    Smoke rings are fascinating, to humans and animals alike.Experienced cigarette smokers blow them for entertainment while dolphins play with air-filled underwater rings that they know how to puff.~Smoke ring machines can be bought from science gadget shops and Lord Kelvin explains in a paper [Lord Kelvin, Proceedings of the Royal Society of Edinburgh, Vol. VI (1867), p. 94; reprinted in Philos. Mag. Vol. XXXIV (1867), p.~15] how one can be constructed from a cardboard box. Even Mount Etna [http://news.bbc.co.uk/1/hi/sci/tech/696953.stm] and our Sun [http://spacescience.com/headlines/y2000/ast03feb_1.htm] are known to be sources of huge smoke rings. But a smoke ring is not only fun to watch. It is also an organized structure with the ability to engage in complex acts, best exemplified by the leapfrogging motion of two smoke rings. Here we propose that the leapfrogging actually encodes very important Physics: It is a direct three dimensional generalization of the motion that in the two dimensional context is responsible for exotic exchange statistics which rules the properties of structures and materials such as quantum Hall systems and high-temperature superconductors. By employing very simple and universal concepts with roots in the hydrodynamical Euler equation, the universal law that describes the properties of fluids and gases, we argue that three dimensional exotic exchange statistics is commonplace. Our observations could have far reaching consequences in fluids and gases which are subject to the laws of quantum mechanics, from helium supefluids to Bose-Einstein condensed alkali gases and even metallic hydrogen in its liquid phases.

  20. An Introduction to Drug Discovery by Probing Protein-Substrate Interactions Using Saturation Transfer Difference-Nuclear Magnetic Resonance (STD-NMR)

    ERIC Educational Resources Information Center

    Guegan, Jean-Paul; Daniellou, Richard

    2012-01-01

    NMR spectroscopy is a powerful tool for characterizing and identifying molecules and nowadays is even used to characterize complex systems in biology. In the experiment presented here, students learned how to apply this modern technique to probe interactions between small molecules and proteins. With the use of simple organic synthesis, students…

  1. Design and validation of an angle-resolved low-coherence interferometry fiber probe for in vivo clinical measurements of depth-resolved nuclear morphology.

    PubMed

    Zhu, Yizheng; Terry, Neil G; Woosley, John T; Shaheen, Nicholas J; Wax, Adam

    2011-01-01

    We present a novel Fourier-domain angle-resolved low-coherence interferometry (a /LCI) fiber probe designed for in vivo clinical application in gastrointestinal endoscopy. The a/LCI technique measures the depth-resolved angular scattering distribution to determine the size distribution and optical density of cell nuclei for assessing the health of epithelial tissues. Clinical application is enabled by an endoscopic fiber-optic probe that employs a 2.3-m-long coherent fiber bundle and is compatible with the standard 2.8-mm-diam biopsy channel of a gastroscope. The probe allows for real-time data acquisition by collecting the scattering from multiple angles in parallel, enabled by the Fourier domain approach. The performance of the probe is characterized through measurement of critical parameters. The depth-resolved sizing capability of the system is demonstrated using single- and double-layer microsphere phantoms with subwavelength sizing precision and accuracy achieved. Initial results from a clinical feasibility test are also presented to show in vivo application in the human esophagus.

  2. Design and validation of an angle-resolved low-coherence interferometry fiber probe for in vivo clinical measurements of depth-resolved nuclear morphology

    NASA Astrophysics Data System (ADS)

    Zhu, Yizheng; Terry, Neil G.; Woosley, John T.; Shaheen, Nicholas J.; Wax, Adam

    2011-01-01

    We present a novel Fourier-domain angle-resolved low-coherence interferometry (a /LCI) fiber probe designed for in vivo clinical application in gastrointestinal endoscopy. The a/LCI technique measures the depth-resolved angular scattering distribution to determine the size distribution and optical density of cell nuclei for assessing the health of epithelial tissues. Clinical application is enabled by an endoscopic fiber-optic probe that employs a 2.3-m-long coherent fiber bundle and is compatible with the standard 2.8-mm-diam biopsy channel of a gastroscope. The probe allows for real-time data acquisition by collecting the scattering from multiple angles in parallel, enabled by the Fourier domain approach. The performance of the probe is characterized through measurement of critical parameters. The depth-resolved sizing capability of the system is demonstrated using single- and double-layer microsphere phantoms with subwavelength sizing precision and accuracy achieved. Initial results from a clinical feasibility test are also presented to show in vivo application in the human esophagus.

  3. CORROSION MONITORING IN HANFORD NUCLEAR WASTE STORAGE TANKS DESIGN AND DATA FROM 241-AN-102 MULTI-PROBE CORROSION MONITORING SYSTEM

    SciTech Connect

    ANDA VS; EDGEMON GL; HAGENSEN AR; BOOMER KD; CAROTHERS KG

    2009-01-08

    In 2008, a new Multi-Probe Corrosion Monitoring System (MPCMS) was installed in double-shell tank 241-AN-102 on the U.S. Department of Energy's Hanford Site in Washington State. Developmental design work included laboratory testing in simulated tank 241-AN-102 waste to evaluate metal performance for installation on the MPCMS as secondary metal reference electrodes. The MPCMS design includes coupon arrays as well as a wired probe which facilitates measurement of tank potential as well as corrosion rate using electrical resistance (ER) sensors. This paper presents the MPCMS design, field data obtained following installation of the MPCMS in tank 241-AN-102, and a comparison between laboratory potential data obtained using simulated waste and tank potential data obtained following field installation.

  4. The experimental set-up of the RIB in-flight facility EXOTIC

    NASA Astrophysics Data System (ADS)

    Pierroutsakou, D.; Boiano, A.; Boiano, C.; Di Meo, P.; La Commara, M.; Manea, C.; Mazzocco, M.; Nicoletto, M.; Parascandolo, C.; Signorini, C.; Soramel, F.; Strano, E.; Toniolo, N.; Torresi, D.; Tortone, G.; Anastasio, A.; Bettini, M.; Cassese, C.; Castellani, L.; Corti, D.; Costa, L.; De Fazio, B.; Galet, G.; Glodariu, T.; Grebosz, J.; Guglielmetti, A.; Molini, P.; Pontoriere, G.; Rocco, R.; Romoli, M.; Roscilli, L.; Sandoli, M.; Stroe, L.; Tessaro, M.; Zatti, P. G.

    2016-10-01

    We describe the experimental set-up of the Radioactive Ion Beam (RIB) in-flight facility EXOTIC consisting of: (a) two position-sensitive Parallel Plate Avalanche Counters (PPACs), dedicated to the event-by-event tracking of the produced RIBs and to time of flight measurements and (b) the new high-granularity compact telescope array EXPADES (EXotic PArticle DEtection System), designed for nuclear physics and nuclear astrophysics experiments employing low-energy light RIBs. EXPADES consists of eight ΔE -Eres telescopes arranged in a cylindrical configuration around the target. Each telescope is made up of two Double Sided Silicon Strip Detectors (DSSSDs) with a thickness of 40/60 μm and 300 μm for the ΔE and Eres layer, respectively. Additionally, eight ionization chambers were constructed to be used as an alternative ΔE stage or, in conjunction with the entire DSSSD array, to build up more complex triple telescopes. New low-noise multi-channel charge-sensitive preamplifiers and spectroscopy amplifiers, associated with constant fraction discriminators, peak-and-hold and Time to Amplitude Converter circuits were developed for the electronic readout of the ΔE stage. Application Specific Integrated Circuit-based electronics was employed for the treatment of the Eres signals. An 8-channel, 12-bit multi-sampling 50 MHz Analog to Digital Converter, a Trigger Supervisor Board for handling the trigger signals of the whole experimental set-up and an ad hoc data acquisition system were also developed. The performance of the PPACs, EXPADES and of the associated electronics was obtained offline with standard α calibration sources and in-beam by measuring the scattering process for the systems 17O+58Ni and 17O+208Pb at incident energies around their respective Coulomb barriers and, successively, during the first experimental runs with the RIBs of the EXOTIC facility.

  5. Issues and Opportunities in Exotic Hadrons

    NASA Astrophysics Data System (ADS)

    Briceño, R. A.; Cohen, T. D.; Coito, S.; Dudek, J. J.; Eichten, E.; Fischer, C. S.; Fritsch, M.; Gradl, W.; Jackura, A.; Kornicer, M.; Krein, G.; Lebed, R. F.; Machado, F. A.; Mitchell, R. E.; Morningstar, C. J.; Peardon, M.; Pennington, M. R.; Peters, K.; Richard, J. M.; Shen, C. P.; Shepherd, M. R.; Skwarnicki, T.; Swanson, E. S.; Szczepaniak, A. P.; Yuan, C. Z.

    2016-04-01

    The last few years have been witness to a proliferation of new results concerning heavy exotic hadrons. Experimentally, many new signals have been discovered that could be pointing towards the existence of tetraquarks, pentaquarks, and other exotic configurations of quarks and gluons. Theoretically, advances in lattice field theory techniques place us at the cusp of understanding complex coupled-channel phenomena, modelling grows more sophisticated, and effective field theories are being applied to an ever greater range of situations. It is thus an opportune time to evaluate the status of the field. In the following, a series of high priority experimental and theoretical issues concerning heavy exotic hadrons is presented. Supported by U.S. Department of Energy (Cohen); the Institute of Modern Physics and Chinese Academy of Sciences under contract Y104160YQ0 and agreement No. 2015-BH-02 (Coito); the U.S. Department of Energy, for grant DE-AC05-06OR23177, under which Jefferson Science Associates, LLC, manages and operates Jefferson Laboratory and DE-SC0006765, Early Career award (Dudek); Fermilab, operated by the Fermi Research Alliance under contract number DEAC02-07CH11359 with the U.S. Department of Energy (Eichten); BMBF, under contract No. 06GI7121, and the DAAD under contract No. 56889822 and by the Helmholtz International Center for FAIR within the LOEWE program of the State of Hesse (Fischer); the German Research Foundation DFG under contract number Collaborative Research Centre CRC-1044 (Gradl); the Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq, Grant No. 305894/2009-9 and Fundação de Amparo à Pesquisa do Estado de São Paulo - FAPESP, Grant No. 2013/01907-0 (Krein); U.S. National Science Foundation, under grants PHY-1068286 and PHY-1403891 (Lebed); the Brazilian National Council for Scientific and Technological Development under grant CNPq/CAPES-208188/2014-2 (Machado); U.S. Department of Energy under grant DE-FG02-05ER41374

  6. Recent developments in the eikonal description of the breakup of exotic nuclei

    NASA Astrophysics Data System (ADS)

    Capel, P.; Colomer, F.; Esbensen, H.; Fukui, T.; Johnson, R. C.; Nunes, F. M.; Ogata, K.

    2016-06-01

    The study of exotic nuclear structures, such as halo nuclei, is usually performed through nuclear reactions. An accurate reaction model coupled to a realistic description of the projectile is needed to correctly interpret experimental data. In this contribution, I briefly summarise the assumptions made within the modelling of reactions involving halo nuclei. I describe briefly the Continuum-Discretised Coupled Channel method (CDCC) and the Dynamical Eikonal Approximation (DEA) in particular and present a comparison between them for the breakup of 15C on Pb at 68AMeV. I show the problem faced by the eikonal approximation at low energy and detail a correction that enables its extension down to lower beam energies. A new reaction observable is also presented. It consists of the ratio between angular distributions for two different processes, such as elastic scattering and breakup. This ratio is completely independent of the reaction mechanism and hence is more sensitive to the projectile structure than usual reaction observables, which makes it a very powerful tool to study exotic structures far from stability.

  7. Exotic grasslands on reclaimed midwestern coal mines: An ornithological perspective

    SciTech Connect

    Scott, P.E.; Lima, S.L.

    2004-07-01

    The largest grasslands in Indiana and Illinois are on reclaimed surface coal mines, which are numerous in the Illinois Coal Basin. The reclamation goal of establishing a vegetation cover with inexpensive, hardy exotic grass species (e.g., tall fescue, smooth brome) inadvertently created persistent, large grassland bird refuges. We review research documenting the importance of these sites for native prairie birds. On mines, grassland specialist birds (restricted to grassland throughout their range) prefer sites dominated by exotic grasses to those rich in forbs, whereas nonspecialist bird species show no significant preference. Midwestern mine grasslands potentially could be converted into landscapes that include native warm-season grasses and forbs adapted to the relatively dry, poor soil conditions, in addition to the present successful exotic grass stands. A key question is whether native mixtures will resist conversion to forb-rich or woody growth over the long term, as the exotic grasses have done.

  8. Exotic dual of type II double field theory

    NASA Astrophysics Data System (ADS)

    Bergshoeff, Eric A.; Hohm, Olaf; Riccioni, Fabio

    2017-04-01

    We perform an exotic dualization of the Ramond-Ramond fields in type II double field theory, in which they are encoded in a Majorana-Weyl spinor of O (D , D). Starting from a first-order master action, the dual theory in terms of a tensor-spinor of O (D , D) is determined. This tensor-spinor is subject to an exotic version of the (self-)duality constraint needed for a democratic formulation. We show that in components, reducing O (D , D) to GL (D), one obtains the expected exotically dual theory in terms of mixed Young tableaux fields. To this end, we generalize exotic dualizations to self-dual fields, such as the 4-form in type IIB string theory.

  9. Bio-Invasions: The Spread of Exotic Species.

    ERIC Educational Resources Information Center

    Bright, Chris

    1995-01-01

    Human mobility has radically increased the rate at which large numbers of living things are moving from one ecosystem to another. Discusses how ecosystems change when "exotic" species invade natural communities and notes efforts to control adverse effects. (LZ)

  10. Fecal shedding of Salmonella in exotic felids.

    PubMed

    Clyde, V L; Ramsay, E C; Bemis, D A

    1997-06-01

    Two collections of exotic felids were screened for the presence of Salmonella by selective fecal culture utilizing selenite broth and Hektoen enteric agar. In > 90% of the samples, Salmonella was isolated from a single culture. A commercial horsemeat-based diet was fed in both collections, and one collection also was fed raw chicken. Salmonella was cultured from the raw chicken and the horsemeat diet for both collections. Multiple Salmonella serotypes were identified, with S. typhimurium and S. typhimurium (copenhagen) isolated most frequently. Approximately half of the Salmonella isolates demonstrated multiple antibiotic resistance. The ability to harbor Salmonella as normal nonpathogenic bacteria of the gastrointestinal tract may be a physiological adaptation to carnivory. The high rate of fecal shedding of Salmonella in healthy individuals clouds the interpretation of a positive fecal culture in an ill felid, or one with diarrhea. All zoo employees having contact with cat feces or raw diets have a high rate of occupational exposure to Salmonella and should exercise appropriate hygienic precautions.

  11. Exotic colored scalars at the LHC

    NASA Astrophysics Data System (ADS)

    Blum, Kfir; Efrati, Aielet; Frugiuele, Claudia; Nir, Yosef

    2017-02-01

    We study the phenomenology of exotic color-triplet scalar particles X with charge | Q| = 2 /3 , 4 /3 , 5 /3 , 7 /3 , 8 /3 and 10 /3. If X is an SU(2) W -non-singlet, mass splitting within the multiplet allows for cascade decays of the members into the lightest state. We study examples where the lightest state, in turn, decays into a three-body W ± jj final state, and show that in such case the entire multiplet is compatible with indirect precision tests and with direct collider searches for continuum pair production of X down to m X ˜ 250 GeV. However, bound states S, made of XX † pairs at m S ≈ 2 m X , form under rather generic conditions and their decay to diphoton can be the first discovery channel of the model. Furthermore, for SU(2) W -non-singlets, the mode S → W + W - may be observable and the width of S → γγ and S → jj may appear large as a consequence of mass splittings within the X-multiplet. As an example we study in detail the case of an SU(2) W -quartet, finding that m X ≃ 450 GeV is allowed by all current searches.

  12. Controlling the exotic diseases: 2. Nursing management.

    PubMed Central

    Best, H R; Clayton, A J

    1980-01-01

    Advance planning can facilitate the care of a patient with an exotic disease who is admitted to a hospital that lacks facilities for high-security isolation. The Department of National Health and Welfare contingency plan for dealing with such patients lacks specific information in a number of areas of medical care, as described in this paper. Consideration must be given to the number of personnel trained and readied for employment, the criteria for selection and special preparation. The protective clothing generally used for hospital isolation procedures is inadequate. Several types of special clothing, including a respirator, are available for total protection of personnel; the clothing may be uncomfortable when worn for long periods, and does restrict movement, vision and communication. All persons entering the isolation suite must change into fully protective clothing, and double layers of clothing are required for direct patient care. All personnel must shower and change before leaving the isolation suite. Suitable facilities for dressing and showering, together with entry and exit routines, must be considered. Hand washing, daily cleaning procedures and disposal of liquid and solid wastes all require special procedures. The social and psychologic problems of patients and their families must also be considered. Preplanning is required to decrease the risks involved in monitoring vital signs and implementing emergency procedures requiring contact with the patient's blood. Images FIG. 1 PMID:7437990

  13. Highly excited and exotic meson spectroscopy from lattice QCD

    SciTech Connect

    Christopher Thomas

    2011-05-01

    I will discuss recent progress in extracting highly excited and exotic meson spectra using lattice QCD. New results in the light meson sector will be presented, where a combination of techniques have enabled us to confidently identify the spin of extracted states. Highlights include many states with exotic quantum numbers and, for the first time in a lattice QCD calculation, spin-four states. I will conclude with comments on future prospects.

  14. Pond permanence and the effects of exotic vertebrates on anurans

    USGS Publications Warehouse

    Adams, M.J.

    2000-01-01

    In many permanent ponds throughout western North America, the introduction of a variety of exotic fish and bullfrogs (Rana catesbeiana) correlates with declines in native amphibians. Direct effects of exotics are suspected to be responsible for the rarity of some native amphibians and are one hypothesis to explain the prevalence of amphibian declines in western North America. However, the prediction that the permanent ponds occupied by exotics would be suitable for native amphibians if exotics were absent has not been tested. I used a series of enclosure experiments to test whether survival of northern red-legged frog (Rana aurora aurora) and Pacific treefrog (Hyla regilla) larvae is equal in permanent and temporary ponds in the Puget Lowlands, Washington State, USA. I also examined the direct effects of bullfrog larvae and sunfish. Survival of both species of native anuran larvae was generally lower in permanent ponds. Only one permanent pond out of six was an exception to this pattern and exhibited increased larval survival rates in the absence of direct effects by exotics. The presence of fish in enclosures reduced survival to near zero for both native species. An effect of bullfrog larvae on Pacific treefrog larval survival was not detected, but effects on red-legged frog larvae were mixed. A hypothesis that food limitation is responsible for the low survival of native larvae in some permanent ponds was not supported. My results confirm that direct negative effects of exotic vertebrates on native anurans occur but suggest that they may not be important to broad distribution patterns. Instead, habitat gradients or indirect effects of exotics appear to play major roles. I found support for the role of permanence as a structuring agent for pond communities in the Puget Lowlands, but neither permanence nor exotic vertebrates fully explained the observed variability in larval anuran survival.

  15. The mass formula for an exotic BTZ black hole

    SciTech Connect

    Zhang, Baocheng

    2016-04-15

    An exotic Bañados–Teitelboim–Zanelli (BTZ) black hole has an angular momentum larger than its mass in three dimension (3D), which suggests the possibility that cosmic censorship could be violated if angular momentum is extracted by the Penrose process. In this paper, we propose a mass formula for the exotic BTZ black hole and show no violation of weak cosmic censorship in the gedanken process above by understanding properly its mass formula. Unlike the other black holes, the total energy of the exotic BTZ black hole is represented by the angular momentum instead of the mass, which supports a basic point of view that the same geometry should be determined by the same energy in 3D general relativity whose equation of motion can be given either by normal 3D Einstein gravity or by exotic 3D Einstein gravity. However, only the mass of the exotic black hole is related to the thermodynamics and other forms of energy are “dumb”, which is consistent with the earlier thermodynamic analysis about exotic black holes.

  16. The mass formula for an exotic BTZ black hole

    NASA Astrophysics Data System (ADS)

    Zhang, Baocheng

    2016-04-01

    An exotic Bañados-Teitelboim-Zanelli (BTZ) black hole has an angular momentum larger than its mass in three dimension (3D), which suggests the possibility that cosmic censorship could be violated if angular momentum is extracted by the Penrose process. In this paper, we propose a mass formula for the exotic BTZ black hole and show no violation of weak cosmic censorship in the gedanken process above by understanding properly its mass formula. Unlike the other black holes, the total energy of the exotic BTZ black hole is represented by the angular momentum instead of the mass, which supports a basic point of view that the same geometry should be determined by the same energy in 3D general relativity whose equation of motion can be given either by normal 3D Einstein gravity or by exotic 3D Einstein gravity. However, only the mass of the exotic black hole is related to the thermodynamics and other forms of energy are "dumb", which is consistent with the earlier thermodynamic analysis about exotic black holes.

  17. Effects of exotic species on Yellowstone's grizzly bears

    USGS Publications Warehouse

    Reinhart, D.P.; Haroldson, Mark A.; Mattson, D.J.; Gunther, Kerry A.

    2001-01-01

    Humans have affected grizzly bears (Ursus arctos horribilis) by direct mortality, competition for space and resources, and introduction of exotic species. Exotic organisms that have affected grizzly bears in the Greater Yellowstone Area include common dandelion (Taraxacum officinale), nonnative clovers (Trifolium spp.), domesticated livestock, bovine brucellosis (Brucella abortus), lake trout (Salvelinus namaycush), and white pine blister rust (Cronartium ribicola). Some bears consume substantial amounts of dandelion and clover. However, these exotic foods provide little digested energy compared to higher-quality bear foods. Domestic livestock are of greater energetic value, but use of this food by bears often leads to conflicts with humans and subsequent increases in bear mortality. Lake trout, blister rust, and brucellosis diminish grizzly bears foods. Lake trout prey on native cutthroat trout (Oncorhynchus clarkii) in Yellowstone Lake; white pine blister rust has the potential to destroy native whitebark pine (Pinus albicaulis) stands; and management response to bovine brucellosis, a disease found in the Yellowstone bison (Bison bison) and elk (Cervus elaphus), could reduce populations of these 2 species. Exotic species will likely cause more harm than good for Yellowstone grizzly bears. Managers have few options to mitigate or contain the impacts of exotics on Yellowstones grizzly bears. Moreover, their potential negative impacts have only begun to unfold. Exotic species may lead to the loss of substantial highquality grizzly bear foods, including much of the bison, trout, and pine seeds that Yellowstone grizzly bears currently depend upon.

  18. Search for millisecond pulsars at the GMRT and the exotic discoveries

    NASA Astrophysics Data System (ADS)

    Bhaswati Bhattacharyya, Bhaswati

    There are, arguably, no other astronomical object whose discovery and subsequent studies provides more insight in such a rich variety of physics and astrophysics than the millisecond pulsars (MSPs). MSPs are a small sub-class of pulsars, rotating with periods of only a few milliseconds and due to their extraordinary rotational stability, MSPs can be considered as astrophysical clocks. The search for such exotic objects will not only enhance the MSP population, but will also allow much wider probe to explore their evolutionary history. We have discovered six MSPs with much diverse characteristics at the positions of Fermi LAT unassociated sources using the GMRT. Being the first galactic disk millisecond pulsars discovered at the GMRT, these discoveries are very important scientific achievement from India and illustrate the importance of low-frequency search for nearby millisecond pulsars. The discovery of these precise astrophysical clocks demands much finer grid in search phase space, which is completely driven by the number crunching capability of the High Performance Compute engine. The discoveries of binary MSPs in exotic evolutionary phases demands complete 3-D search. For example, 7.5 Tflops of compute power is used for the discovery of a very compact binary MSP, a Black Widow pulsar. This pulsar eclipses for about 13% of its orbit by a very low-mass companion (0.017 M_{⊙}). Such Black Widow pulsars are missing link between the isolated and fully recycled pulsars, where the pulsar is ablating its companion creating significant amount of intra-binary material to obscure the pulsar emission. Radio timing ephemeris allowed us to detect the gamma-ray pulsations from this millisecond pulsar. The details of the GMRT discoveries, the interesting results from our observations and the possible scientific impact of the discoveries of such exotic systems will be illustrated in this presentation.

  19. Electron transport through nuclear pasta in magnetized neutron stars

    NASA Astrophysics Data System (ADS)

    Yakovlev, D. G.

    2015-10-01

    We present a simple model for electron transport in a possible layer of exotic nuclear clusters (in the so-called nuclear pasta layer) between the crust and liquid core of a strongly magnetized neutron star. The electron transport there can be strongly anisotropic and gyrotropic. The anisotropy is produced by different electron effective collision frequencies along and across local symmetry axis in domains of exotic ordered nuclear clusters and by complicated effects of the magnetic field. We also calculate averaged kinetic coefficients in case local domains are freely oriented. Possible applications of the obtained results and open problems are outlined.

  20. Ticks imported to Europe with exotic reptiles.

    PubMed

    Mihalca, Andrei Daniel

    2015-09-30

    It is known that traded exotic animals carry with them an immense number of associated symbionts, including parasites. Reptiles are no exception. Most of the imported reptiles originate from tropical countries and their possibility to carry potentially dangerous pathogens is high. According to CITES, Europe is currently the main reptile importer in the world. Despite this, there is no review or analysis available for the risk related to the importation of tick-borne diseases with traded reptile to the EU. The main aim of the manuscript is to provide a review on the available literature on ticks introduced to and exchanged between European countries via the live reptile trade. So far, the published reports of ticks imported on reptiles are limited to few European countries: Italy, Poland, Spain, Netherlands, Belgium, Slovenia and UK. The following species have been reported: Hyalomma aegyptium, Amblyomma dissimile, Amblyomma exornatum, Amblyomma flavomaculatum, Amblyomma fuscolineatum, Amblyomma latum, Amblyomma quadricavum, Amblyomma marmoreum, Amblyomma nuttalli, Amblyomma sparsum, Amblyomma sphenodonti, Amblyomma transversale and Amblyomma varanense. The majority of species are of African origin, followed by American and Asian species. All groups of reptiles (chelonians, snakes, lizards, crocodiles, tuataras) were involved. However, it seems that certain groups (i.e. tortoises of genus Testudo, monitor lizards of genus Varanus, snakes of genus Python) are more important as host for imported ticks, but this may be related to higher levels of international trade. Even fewer are the reports of tick-borne pathogens associated with imported reptile ticks. Despite the diversity of tick species reported on imported reptiles, the situations of truly invasive species are atypical and are limited in natural environments to maximum two cases where H. aegyptium was involved. Otherwise, the risk associated with reptile trade for introduction of invasive tick to Europe is low

  1. Rotation and shape changes in {sup 151}Tb and {sup 196}Pb: Probes of nuclear structure and tunneling process in warm nuclei. I. Experimental analysis

    SciTech Connect

    Leoni, S.; Bracco, A.; Camera, F.; Corsi, A.; Crespi, F. C. L.; Montanari, D.; Pignanelli, M.; Benzoni, G.; Blasi, N.; Million, B.; Vigezzi, E.; Wieland, O.; Mason, P.; Matsuo, M.; Shimizu, Y. R.; Curien, D.; Duchene, G.; Robin, J.; Bednarczyk, P.; Kmiecik, M.

    2009-06-15

    The {gamma} decay associated with the warm rotation of the superdeformed nuclei {sup 151}Tb and {sup 196}Pb has been measured with the Euroball IV array. Several experimental quantities are presented, putting strong constraints on the decay dynamics in the superdeformed well. The data are successfully reproduced using a Monte Carlo simulation of the {gamma} decay based on microscopically calculated energy levels, E2 decay probabilities, collective mass parameters, and potential energy barriers between the wells associated with normal and super deformation. This allows one to test the basic ingredients of the physical process, such as the strength of the two-body residual interaction and the potential barriers as a function of spin and excitation energy. We also show that the data probe the E1 strength function, indicating an enhancement around 1-2 MeV {gamma} rays, which might be related to octupole vibrations.

  2. 129Xe nuclear magnetic resonance study of pitch-based activated carbon modified by air oxidation/pyrolysis cycles: a new approach to probe the micropore size.

    PubMed

    Romanenko, Konstantin V; Py, Xavier; d'Espinose de Lacaillerie, Jean-Baptiste; Lapina, Olga B; Fraissard, Jacques

    2006-02-23

    (129)Xe NMR has been used to study a series of homologous activated carbons obtained from a KOH-activated pitch-based carbon molecular sieve modified by air oxidation/pyrolysis cycles. A clear correlation between the pore size of microporous carbons and the (129)Xe NMR of adsorbed xenon is proposed for the first time. The virial coefficient delta(Xe)(-)(Xe) arising from binary xenon collisions varied linearly with the micropore size and appeared to be a better probe of the microporosity than the chemical shift extrapolated to zero pressure. This correlation was explained by the fact that the xenon collision frequency increases with increasing micropore size. The chemical shift has been shown to vary very little with temperature (less than 9 ppm) for xenon trapped inside narrow and wide micropores. This is indicative of a smooth xenon-surface interaction potential.

  3. Investigation of the nuclear structure of 33Al through beta-decay of 33Mg to probe the island of inversion

    NASA Astrophysics Data System (ADS)

    Zidar, Tammy; Griffin Collaboration

    2016-09-01

    Away from the valley of stability, some nuclei have been found to have ground state properties that are different than those naively expected from the nuclear shell model. Around the ``island of inversion'', N = 20 closed shell nucleus 32Mg has large ground state deformations occur in association with intruder configurations from the f7 / 2 shell. The nuclear structure of transitional nuclei, in which the normal and intruder configurations compete, can be used to inform theoretical models used to explain the inversion mechanism. 32Mg is known to have a deformed ground-state configuration, while 34Si displays a normal one. In the present work we studied the intermediate 33Al through the β-decay of 33Mg to clarify conflicting previous results regarding its structure. 33Mg was delivered to the GRIFFIN high-purity germanium γ-ray spectrometer coupled with the SCEPTAR plastic scintillator β particle detector. High efficiency of the GRIFFIN detector provides new γ- γ coincidences to elucidate the excited state structure of 33Al, and its capability to detect weak transitions has provided β-decay branching ratios for the 33Mg -> 33Al -> 33Si decay chain. The Canadian Foundation for Innovation, The National Research Council of Canada and the Natural Sciences and Engineering Research Council of Canada.

  4. Optical probe

    DOEpatents

    Hencken, Kenneth; Flower, William L.

    1999-01-01

    A compact optical probe is disclosed particularly useful for analysis of emissions in industrial environments. The instant invention provides a geometry for optically-based measurements that allows all optical components (source, detector, rely optics, etc.) to be located in proximity to one another. The geometry of the probe disclosed herein provides a means for making optical measurements in environments where it is difficult and/or expensive to gain access to the vicinity of a flow stream to be measured. Significantly, the lens geometry of the optical probe allows the analysis location within a flow stream being monitored to be moved while maintaining optical alignment of all components even when the optical probe is focused on a plurality of different analysis points within the flow stream.

  5. Search for exotic spin-dependent interactions with a spin-exchange relaxation-free magnetometer

    SciTech Connect

    Chu, Pinghan; Kim, Young Jin; Savukov, Igor Mykhaylovich

    2016-08-15

    We propose a novel experimental approach to explore exotic spin-dependent interactions using a spin-exchange relaxation-free (SERF) magnetometer, the most sensitive noncryogenic magnetic-field sensor. This approach studies the interactions between optically polarized electron spins located inside a vapor cell of the SERF magnetometer and unpolarized or polarized particles of external solid-state objects. The coupling of spin-dependent interactions to the polarized electron spins of the magnetometer induces the tilt of the electron spins, which can be detected with high sensitivity by a probe laser beam similarly as an external magnetic field. Lastly, we estimate that by moving unpolarized or polarized objects next to the SERF Rb vapor cell, the experimental limit to the spin-dependent interactions can be significantly improved over existing experiments, and new limits on the coupling strengths can be set in the interaction range below 10–2 m.

  6. Search for exotic spin-dependent interactions with a spin-exchange relaxation-free magnetometer

    DOE PAGES

    Chu, Pinghan; Kim, Young Jin; Savukov, Igor Mykhaylovich

    2016-08-15

    We propose a novel experimental approach to explore exotic spin-dependent interactions using a spin-exchange relaxation-free (SERF) magnetometer, the most sensitive noncryogenic magnetic-field sensor. This approach studies the interactions between optically polarized electron spins located inside a vapor cell of the SERF magnetometer and unpolarized or polarized particles of external solid-state objects. The coupling of spin-dependent interactions to the polarized electron spins of the magnetometer induces the tilt of the electron spins, which can be detected with high sensitivity by a probe laser beam similarly as an external magnetic field. Lastly, we estimate that by moving unpolarized or polarized objects nextmore » to the SERF Rb vapor cell, the experimental limit to the spin-dependent interactions can be significantly improved over existing experiments, and new limits on the coupling strengths can be set in the interaction range below 10–2 m.« less

  7. Ultrafast photo-induced nuclear relaxation of a conformationally disordered conjugated polymer probed with transient absorption and femtosecond stimulated Raman spectroscopies.

    PubMed

    Yu, Wenjian; Donohoo-Vallett, Paul J; Zhou, Jiawang; Bragg, Arthur E

    2014-07-28

    A combination of transient absorption (TAS) and femtosecond stimulated Raman (FSRS) spectroscopies were used to interrogate the photo-induced nuclear relaxation dynamics of poly(3-cyclohexyl,4-methylthiophene) (PCMT). The large difference in inter-ring dihedral angles of ground and excited-state PCMT make it an ideal candidate for studying large-amplitude vibrational relaxation associated with exciton trapping. Spectral shifting in the S1 TA spectra on sub-ps timescales (110 ± 20 and 800 ± 100 fs) is similar to spectroscopic signatures of excited-state relaxation observed with related photoexcited conjugated polymers and which have been attributed to exciton localization and a combination of resonant energy transfer and torsional relaxation, respectively. Measurements made with both techniques reveal fast PCMT S1 decay and triplet formation (τS1 = 25-32 ps), which is similar to the excited-state dynamics of short oligothiophenes and highly twisted polyconjugated molecules. On ultrafast timescales FSRS of S1 PCMT offers a new perspective on the nuclear dynamics that underlie localization of excitons in photoexcited conjugated polymers: Spectral dynamics in the C=C stretching region (1400-1600 cm(-1)) include a red-shift of the in-phase C=C stretching frequency, as well as a change in the relative intensity of in-phase and out-of-phase stretch intensities on a timescale of ∼100 fs. Both changes indicate an ultrafast vibrational distortion that increases the conjugation length in the region of the localized excitation and are consistent with exciton self-localization or trapping. Wavelength-dependent excited-state FSRS measurements further demonstrate that the C=C stretching frequency provides a useful spectroscopic handle for interrogating the degree of delocalization in excited conjugated polymers given the selectivity achieved via resonance enhancement.

  8. Ultrafast photo-induced nuclear relaxation of a conformationally disordered conjugated polymer probed with transient absorption and femtosecond stimulated Raman spectroscopies

    SciTech Connect

    Yu, Wenjian; Donohoo-Vallett, Paul J.; Zhou, Jiawang; Bragg, Arthur E.

    2014-07-28

    A combination of transient absorption (TAS) and femtosecond stimulated Raman (FSRS) spectroscopies were used to interrogate the photo-induced nuclear relaxation dynamics of poly(3-cyclohexyl,4-methylthiophene) (PCMT). The large difference in inter-ring dihedral angles of ground and excited-state PCMT make it an ideal candidate for studying large-amplitude vibrational relaxation associated with exciton trapping. Spectral shifting in the S{sub 1} TA spectra on sub-ps timescales (110 ± 20 and 800 ± 100 fs) is similar to spectroscopic signatures of excited-state relaxation observed with related photoexcited conjugated polymers and which have been attributed to exciton localization and a combination of resonant energy transfer and torsional relaxation, respectively. Measurements made with both techniques reveal fast PCMT S{sub 1} decay and triplet formation (τ{sub S1} = 25–32 ps), which is similar to the excited-state dynamics of short oligothiophenes and highly twisted polyconjugated molecules. On ultrafast timescales FSRS of S{sub 1} PCMT offers a new perspective on the nuclear dynamics that underlie localization of excitons in photoexcited conjugated polymers: Spectral dynamics in the C=C stretching region (1400–1600 cm{sup −1}) include a red-shift of the in-phase C=C stretching frequency, as well as a change in the relative intensity of in-phase and out-of-phase stretch intensities on a timescale of ∼100 fs. Both changes indicate an ultrafast vibrational distortion that increases the conjugation length in the region of the localized excitation and are consistent with exciton self-localization or trapping. Wavelength-dependent excited-state FSRS measurements further demonstrate that the C=C stretching frequency provides a useful spectroscopic handle for interrogating the degree of delocalization in excited conjugated polymers given the selectivity achieved via resonance enhancement.

  9. Study on microstructural changes in thermally-aged stainless steel weld-overlay cladding of nuclear reactor pressure vessels by atom probe tomography

    NASA Astrophysics Data System (ADS)

    Takeuchi, T.; Kameda, J.; Nagai, Y.; Toyama, T.; Nishiyama, Y.; Onizawa, K.

    2011-08-01

    The effect of thermal aging on microstructural changes was investigated in stainless steel weld-overlay cladding composed of 90% austenite and 10% δ-ferrite phases using atom probe tomography (APT). In as-received materials subjected to cooling process after post-welding heat treatments (PWHT), a slight fluctuation of the Cr concentration was already observed due to spinodal decomposition in the ferrite phase but not in the austenitic phase. Thermal aging at 400 °C for 10,000 h caused not only an increase in the amplitude of spinodal decomposition but also the precipitation of G phases with composition ratios of Ni:Si:Mn = 16:7:6 in the ferrite phase. The chemical compositions of M 23C 6 type carbides seemed to be formed at the austenite/ferrite interface were analyzed. The analyses of the magnitude of the spinodal decomposition and the hardness implied that the spinodal decomposition was the main cause of the hardening.

  10. ICENES `91:Sixth international conference on emerging nuclear energy systems. Program and abstracts

    SciTech Connect

    Not Available

    1991-12-31

    This document contains the program and abstracts of the sessions at the Sixth International Conference on Emerging Nuclear Energy Systems held June 16--21, 1991 at Monterey, California. These sessions included: The plenary session, fission session, fission and nonelectric session, poster session 1P; (space propulsion, space nuclear power, electrostatic confined fusion, fusion miscellaneous, inertial confinement fusion, {mu}-catalyzed fusion, and cold fusion); Advanced fusion session, space nuclear session, poster session 2P, (nuclear reactions/data, isotope separation, direct energy conversion and exotic concepts, fusion-fission hybrids, nuclear desalting, accelerator waste-transmutation, and fusion-based chemical recycling); energy policy session, poster session 3P (energy policy, magnetic fusion reactors, fission reactors, magnetically insulated inertial fusion, and nuclear explosives for power generation); exotic energy storage and conversion session; and exotic energy storage and conversion; review and closing session.

  11. Exotic taxa less related to native species are more invasive

    PubMed Central

    Strauss, Sharon Y.; Webb, Campbell O.; Salamin, Nicolas

    2006-01-01

    Some species introduced into new geographical areas from their native ranges wreak ecological and economic havoc in their new environment. Although many studies have searched for either species or habitat characteristics that predict invasiveness of exotic species, the match between characteristics of the invader and those of members of the existing native community may be essential to understanding invasiveness. Here, we find that one metric, the phylogenetic relatedness of an invader to the native community, provides a predictive tool for invasiveness. Using a phylogenetic supertree of all grass species in California, we show that highly invasive grass species are, on average, significantly less related to native grasses than are introduced but noninvasive grasses. The match between the invader and the existing native community may explain why exotic pest species are not uniformly noxious in all novel habitats. Relatedness of invaders to the native biota may be one useful criterion for prioritizing management efforts of exotic species. PMID:16581902

  12. Exotic looped trajectories of photons in three-slit interference

    PubMed Central

    Magaña-Loaiza, Omar S; De Leon, Israel; Mirhosseini, Mohammad; Fickler, Robert; Safari, Akbar; Mick, Uwe; McIntyre, Brian; Banzer, Peter; Rodenburg, Brandon; Leuchs, Gerd; Boyd, Robert W.

    2016-01-01

    The validity of the superposition principle and of Born's rule are well-accepted tenants of quantum mechanics. Surprisingly, it has been predicted that the intensity pattern formed in a three-slit experiment is seemingly in contradiction with the most conventional form of the superposition principle when exotic looped trajectories are taken into account. However, the probability of observing such paths is typically very small, thus rendering them extremely difficult to measure. Here we confirm the validity of Born's rule and present the first experimental observation of exotic trajectories as additional paths for the light by directly measuring their contribution to the formation of optical interference fringes. We accomplish this by enhancing the electromagnetic near-fields in the vicinity of the slits through the excitation of surface plasmons. This process increases the probability of occurrence of these exotic trajectories, demonstrating that they are related to the near-field component of the photon's wavefunction. PMID:28008907

  13. Exotic looped trajectories of photons in three-slit interference

    NASA Astrophysics Data System (ADS)

    Magaña-Loaiza, Omar S.; de Leon, Israel; Mirhosseini, Mohammad; Fickler, Robert; Safari, Akbar; Mick, Uwe; McIntyre, Brian; Banzer, Peter; Rodenburg, Brandon; Leuchs, Gerd; Boyd, Robert W.

    2016-12-01

    The validity of the superposition principle and of Born's rule are well-accepted tenants of quantum mechanics. Surprisingly, it has been predicted that the intensity pattern formed in a three-slit experiment is seemingly in contradiction with the most conventional form of the superposition principle when exotic looped trajectories are taken into account. However, the probability of observing such paths is typically very small, thus rendering them extremely difficult to measure. Here we confirm the validity of Born's rule and present the first experimental observation of exotic trajectories as additional paths for the light by directly measuring their contribution to the formation of optical interference fringes. We accomplish this by enhancing the electromagnetic near-fields in the vicinity of the slits through the excitation of surface plasmons. This process increases the probability of occurrence of these exotic trajectories, demonstrating that they are related to the near-field component of the photon's wavefunction.

  14. The Dynamical Dipole Radiation in Dissipative Collisions with Exotic Beams

    NASA Astrophysics Data System (ADS)

    di Toro, M.; Colonna, M.; Rizzo, C.; Baran, V.

    Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. In this work we present a selection of reaction observables in dissipative collisions particularly sensitive to the isovector part of the interaction, i.e. to the symmetry term of the nuclear Equation of State (EoS). At low energies the behavior of the symmetry energy around saturation influences dissipation and fragment production mechanisms. We will first discuss the recently observed Dynamical Dipole Radiation, due to a collective neutron-proton oscillation during the charge equilibration in fusion and deep-inelastic collisions. We will review in detail all the main properties, yield, spectrum, damping and angular distributions, revealing important isospin effects. Reactions induced by unstable 132Sn beams appear to be very promising tools to test the sub-saturation Isovector EoS. Predictions are also presented for deep-inelastic and fragmentation collisions induced by neutron rich projectiles. The importance of studying violent collisions with radioactive beams at low and Fermi energies is finally stressed.

  15. A Large Sample Volume Magic Angle Spinning Nuclear Magnetic Resonance Probe for In-Situ Investigations with Constant Flow of Reactants

    SciTech Connect

    Hu, Jian Z.; Sears, Jesse A.; Mehta, Hardeep S.; Ford, Joseph J.; Kwak, Ja Hun; Zhu, Kake; Wang, Yong; Liu, Jun; Hoyt, David W.; Peden, Charles HF

    2012-02-21

    A large-sample-volume constant-flow magic angle sample spinning (CF-MAS) NMR probe is reported for in-situ studies of the reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions. In our approach, the reactants are introduced into the catalyst bed using a fixed tube at one end of the MAS rotor while a second fixed tube, linked to a vacuum pump, is attached at the other end of the rotor. The pressure difference between both ends of the catalyst bed inside the sample cell space forces the reactants flowing through the catalyst bed, which improves the diffusion of the reactants and products. This design allows the use of a large sample volume for enhanced sensitivity and thus permitting in-situ 13C CF-MAS studies at natural abundance. As an example of application, we show that reactants, products and reaction transition states associated with the 2-butanol dehydration reaction over a mesoporous silicalite supported heteropoly acid catalyst (HPA/meso-silicalite-1) can all be detected in a single 13C CF-MAS NMR spectrum at natural abundance. Coke products can also be detected at natural 13C abundance and under the stopped flow condition. Furthermore, 1H CF-MAS NMR is used to identify the surface functional groups of HPA/meso-silicalite-1 under the condition of in-situ drying . We also show that the reaction dynamics of 2-butanol dehydration using HPA/meso-silicalite-1 as a catalyst can be explored using 1H CF-MAS NMR.

  16. Highly sensitive detection of neodymium ion in small amount of spent nuclear fuel samples using novel fluorescent macrocyclic hexadentate polyaminocarboxylate probe in capillary electrophoresis-laser-induced fluorescence detection.

    PubMed

    Saito, Shingo; Sato, Yoshiyuki; Haraga, Tomoko; Nakano, Yuta; Asai, Shiho; Kameo, Yutaka; Takahashi, Kuniaki; Shibukawa, Masami

    2012-04-06

    A rapid and high-sensitive detection method for the total concentration of Nd ion (total Nd) in a small amount of a spent nuclear fuel sample is urgently required since the precise quantification of total Nd ion makes it possible for burnup (degree of fuel consumption) to be determined. In this work, a capillary electrophoresis-laser-induced fluorescent detection method (CE-LIF) is proposed for the analysis of total Nd in a spent fuel sample solution, with the use of a newly synthesized metal fluorescent probe which has a fluorescein and a macrocylic hexadentate chelating group, FTC-ABNOTA, for lanthanide (Ln) ions. Ln ions were derivatized to form a strongly fluorescent complex with the probe to suppress the quenching of the ligand-centered emission. The detection of Ln complexes in the CE-LIF indicated that the interaction between Ln ions and the FTC-ABNOTA was strong enough not to dissociate during migration. The mutual separation among the Ln-FTC-ABNOTA complexes in CE-LIF was achieved by pH control providing a dynamic ternary complexation (DTC) with hydroxide ions. Using the DTC separation mode, a high resolution of Nd from other Ln ions with high resolution of 1.3-1.9 and a theoretical plate number of 68,000, and a very low detection limit of 22 pM (3.2 ppt, 0.11 attomole amount basis) were successfully obtained. A simulated spent fuel sample containing various metal ions was examined in this method with a good quantification result of 102.1% recovery obtained even with a large excess of U.

  17. Detection of irradiation embrittlement of low-alloy steel for nuclear reactor pressure vessels using a probe type eddy current sensor

    SciTech Connect

    Maeda, Noriyoshi; Yamaguchi, Atsunori; Sugibayashi, Takuya; Kohno, Katsumi

    1999-10-01

    This report describes the results of studies made for the purpose of detecting the irradiation embrittlement of low-alloy steel used for nuclear reactor pressure vessels. For the method of using eddy current to detect material degradation, the device and the sensor employed are light in weight and compact in size, allowing testing without contact. In this study the frequency of input current to the excitation coil is changed in steps of 1 kHz. The output signal is processed by phase detection method, and displayed on a complex plane. It depicts a trajectory as the frequency is changed. To extract features of the trajectories, averaged radius and averaged phase angle are defined and plotted as function of neutron fluence or ductile-brittle transition temperature. Experiment shows that the averaged phase angle and transition temperature decrease as the neutron fluence is increased. Behavior of the averaged phase angle is interpreted employing magnetic permeability and electric conductivity of the test specimens. It becomes clear that electric conductivity decreases as the neutron fluence is increased.

  18. Exotic plant species invade hot spots of native plant diversity

    USGS Publications Warehouse

    Stohlgren, T.J.; Binkley, D.; Chong, G.W.; Kalkhan, M.A.; Schell, L.D.; Bull, K.A.; Otsuki, Y.; Newman, G.; Bashkin, M.; Yowhan, S.

    1999-01-01

    Some theories and experimental studies suggest that areas of low plant species richness may be invaded more easily than areas of high plant species richness. We gathered nested-scale vegetation data on plant species richness, foliar cover, and frequency from 200 1-m2 subplots (20 1000-m2 modified-Whittaker plots) in the Colorado Rockies (USA), and 160 1-m2 subplots (16 1000-m2 plots) in the Central Grasslands in Colorado, Wyoming, South Dakota, and Minnesota (USA) to test the generality of this paradigm. At the 1-m2 scale, the paradigm was supported in four prairie types in the Central Grasslands, where exotic species richness declined with increasing plant species richness and cover. At the 1-m2 scale, five forest and meadow vegetation types in the Colorado Rockies contradicted the paradigm; exotic species richness increased with native-plant species richness and foliar cover. At the 1000-m2 plot scale (among vegetation types), 83% of the variance in exotic species richness in the Central Grasslands was explained by the total percentage of nitrogen in the soil and the cover of native plant species. In the Colorado Rockies, 69% of the variance in exotic species richness in 1000-m2 plots was explained by the number of native plant species and the total percentage of soil carbon. At landscape and biome scales, exotic species primarily invaded areas of high species richness in the four Central Grasslands sites and in the five Colorado Rockies vegetation types. For the nine vegetation types in both biomes, exotic species cover was positively correlated with mean foliar cover, mean soil percentage N, and the total number of exotic species. These patterns of invasibility depend on spatial scale, biome and vegetation type, spatial autocorrelation effects, availability of resources, and species-specific responses to grazing and other disturbances. We conclude that: (1) sites high in herbaceous foliar cover and soil fertility, and hot spots of plant diversity (and

  19. Exotic hadron production in a quark combination model

    SciTech Connect

    Han Wei; Shao Fenglan; Li Shiyuan; Shang Yonghui; Yao Tao

    2009-09-15

    The philosophy on production of exotic hadrons (multiquark states) in the framework of the quark combination model is investigated, taking f{sub 0}(980) as an example. The production rate and p{sub T} spectra of f{sub 0}(980) considered as (ss) or (sqsq), respectively, are calculated and compared in Au+Au collisions at {radical}(s{sub NN})=200 GeV. The unitarity of various combination models, when open for exotic hadron production, is addressed.

  20. One health: zoonoses in the exotic animal practice.

    PubMed

    Souza, Marcy J

    2011-09-01

    Zoonoses make up approximately ¾ of today’s emerging infectious diseases; many of these zoonoses come from exotic pets and wildlife. Recent outbreaks in humans associated with nondomestic animals include Sudden Acute Respiratory Syndrome, Ebola virus, salmonellosis, and monkeypox. Expanding human populations, increased exotic pet ownership and changes in climate may contribute to increased incidence of zoonoses. Education and preventive medicine practices can be applied by veterinarians and other health professionals to reduce the risk of contracting a zoonotic disease. The health of humans, animals, and the environment must be treated as a whole to prevent the transmission of zoonoses.

  1. More on wormholes supported by small amounts of exotic matter

    SciTech Connect

    Kuhfittig, Peter K.F.

    2006-04-15

    Recent papers by Fewster and Roman have emphasized that wormholes supported by arbitrarily small amounts of exotic matter will have to be incredibly fine-tuned if they are to be traversable. This paper discusses a wormhole model that strikes a balance between two conflicting requirements, reducing the amount of exotic matter and fine-tuning the metric coefficients, ultimately resulting in an engineering challenge: one requirement can only be met at the expense of the other. The wormhole model is macroscopic and satisfies various traversability criteria.

  2. Exotic Paired States with Anisotropic Spin-Dependent Fermi Surfaces

    SciTech Connect

    Feiguin, Adrian E.; Fisher, Matthew P. A.

    2009-07-10

    We propose a model for realizing exotic paired states in cold Fermi gases by using a spin-dependent optical lattice to engineer mismatched Fermi surfaces for each hyperfine species. The BCS phase diagram shows a stable paired superfluid state with coexisting pockets of momentum space with gapless unpaired carriers, similar to the Sarma state in polarized mixtures, but in our case the system is unpolarized. We propose the possible existence of an exotic 'Cooper-pair Bose-metal' phase, which has a gap for single fermion excitations but gapless and uncondensed 'Cooper-pair' excitations residing on a 'Bose surface' in momentum space.

  3. JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei

    SciTech Connect

    Papenbrock, Thomas

    2014-05-16

    The grant “JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei ” (DOE DE-FG02-06ER41407) ran from 02/01/2006 thru 12/31/2013. JUSTIPEN is a venue for international collaboration between U.S.-based and Japanese scientists who share an interest in theory of rare isotopes. Since its inception JUSTIPEN has supported many visitors, fostered collaborations between physicists in the U.S. and Japan, and enabled them to deepen our understanding of exotic nuclei and their role in cosmos.

  4. More on wormholes supported by small amounts of exotic matter

    NASA Astrophysics Data System (ADS)

    Kuhfittig, Peter K. F.

    2006-04-01

    Recent papers by Fewster and Roman have emphasized that wormholes supported by arbitrarily small amounts of exotic matter will have to be incredibly fine-tuned if they are to be traversable. This paper discusses a wormhole model that strikes a balance between two conflicting requirements, reducing the amount of exotic matter and fine-tuning the metric coefficients, ultimately resulting in an engineering challenge: one requirement can only be met at the expense of the other. The wormhole model is macroscopic and satisfies various traversability criteria.

  5. Toxoplasma gondii antibodies in exotic wild felids from Brazilian zoos.

    PubMed

    Silva, J C; Ogassawara, S; Marvulo, M F; Ferreira-Neto, J S; Dubey, J P

    2001-09-01

    Serum samples from 37 captive exotic felids in 12 zoos from six Brazilian states were assayed for antibodies to Toxoplasma gondii by the modified agglutination test using formalin-fixed whole tachyzoites. Titers greater than or equal to 1:20 were considered positive. Antibodies to T. gondii were found in 24 of 37 (64.9%) felids, including one European lynx (Lynx lynx), two jungle cats (Felis chaus), two servals (Leptailurus serval), two tigers (Panthera tigris), three leopards (Panthera pardus), and 14 of 27 lions (Panthera leo). This is the first serologic analysis for T. gondii infection in exotic wild felids from Brazilian zoos.

  6. Annihilation physics of exotic galactic dark matter particles

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1990-01-01

    Various theoretical arguments make exotic heavy neutral weakly interacting fermions, particularly those predicted by supersymmetry theory, attractive candidates for making up the large amount of unseen gravitating mass in galactic halos. Such particles can annihilate with each other, producing secondary particles of cosmic-ray energies, among which are antiprotons, positrons, neutrinos, and gamma-rays. Spectra and fluxes of these annihilation products can be calculated, partly by making use of positron electron collider data and quantum chromodynamic models of particle production derived therefrom. These spectra may provide detectable signatures of exotic particle remnants of the big bang.

  7. ALPI Setup as the SPES Accelerator of Exotic Beams

    NASA Astrophysics Data System (ADS)

    Bisoffi, G.; Bassato, G.; Battistella, A.; Bermudez, J.; Bortolato, D.; Canella, S.; Chalykh, B.; Comunian, M.; Facco, A.; Fagotti, E.; Galatà, A.; Giacchini, M.; Gramegna, F.; Lamy, T.; Modanese, P.; Palmieri, A.; Pengo, R.; Pisent, A.; Poggi, M.; Porcellato, A.; Roncolato, C.; Scarpa, D.

    2014-03-01

    The SPES (Selective Production of Exotic Species) project for a national exotic beam facility in Legnaro includes pivotal upgrades of the existing superconducting linac ALPI (Acceleratore Lineare Per Ioni), to make it appropriate as the RIB (Radioactive Ion Beam) accelerator. The new injector, consisting of an Electron Cyclotron Resonance (ECR)-type charge breeder and a radiofrequency quadrupole (RFQ), will be described. Upgrade measures in ALPI to improve beam transmission and final energy, and handle low-intensity RIB will be explained, with the aim of increasing transmission to T > 90%, Ef by ~ 20%, reaching 10 MeV/u for the reference beam 132Sn.

  8. Probing atomic scale transformation of fossil dental enamel using Fourier transform infrared and nuclear magnetic resonance spectroscopy: a case study from the Tugen Hills (Rift Gregory, Kenya).

    PubMed

    Yi, Haohao; Balan, Etienne; Gervais, Christel; Ségalen, Loïc; Roche, Damien; Person, Alain; Fayon, Franck; Morin, Guillaume; Babonneau, Florence

    2014-09-01

    A series of fossil tooth enamel samples was investigated by Fourier transform infrared (FTIR) spectroscopy, (13)C and (19)F magic-angle spinning nuclear magnetic resonance (MAS NMR) and scanning electron microscopy (SEM). Tooth remains were collected in Mio-Pliocene deposits of the Tugen Hills in Kenya. Significant transformations were observed in fossil enamel as a function of increasing fluorine content (up to 2.8wt.%). FTIR spectroscopy revealed a shift of the ν1 PO4 stretching band to higher frequency. The ν2 CO3 vibrational band showed a decrease in the intensity of the primary B-type carbonate signal, which was replaced by a specific band at 864cm(-1). This last band was ascribed to a specific carbonate environment in which the carbonate group is closely associated to a fluoride ion. The occurrence of this carbonate defect was consistently attested by the observation of two different fluoride signals in the (19)F NMR spectra. One main signal, at ∼-100ppm, is related to structural F ions in the apatite channel and the other, at -88ppm, corresponds to the composite defect. These spectroscopic observations can be understood as resulting from the mixture of two phases: biogenic hydroxylapatite (bioapatite) and secondary fluorapatite. SEM observations of the most altered sample confirmed the extensive replacement of the bioapatite by fluorapatite, resulting from the dissolution of the primary bioapatite followed by the precipitation of carbonate-fluorapatite. The ν2 CO3 IR bands can be efficiently used to monitor the extent of this type of bioapatite transformation during fossilization.

  9. Probing the Residual Structure of the Low Populated Denatured State of ADA2h under Folding Conditions by Relaxation Dispersion Nuclear Magnetic Resonance Spectroscopy.

    PubMed

    Pustovalova, Yulia; Kukic, Predrag; Vendruscolo, Michele; Korzhnev, Dmitry M

    2015-08-04

    The structural characterization of low populated states of proteins with accuracy comparable to that achievable for native states is important for understanding the mechanisms of protein folding and function, as well as misfolding and aggregation. Because of the transient nature of these low populated states, they are seldom detected directly under conditions that favor folding. The activation domain of human procarboxypeptidase A2 (ADA2h) is an α/β-protein that forms amyloid fibrils at low pH, presumably initiated from a denatured state with a considerable amount of residual structure. Here we used Carr-Parcell-Meiboom-Gill relaxation dispersion (CPMG RD) nuclear magnetic resonance (NMR) spectroscopy to characterize the structure of the denatured state of the ADA2h I71V mutant under conditions that favor folding. Under these conditions, the lifetime of the denatured state of I71V ADA2h is on the order of milliseconds and its population is approximately several percent, which makes this mutant amenable to studies by CPMG RD methods. The nearly complete set of CPMG RD-derived backbone (15)N, (13)C, and (1)H NMR chemical shifts in the I71V ADA2h denatured state reveals that it retains a significant fraction (up to 50-60%) of nativelike α-helical structure, while the regions encompassing native β-strands are structured to a much lesser extent. The nativelike α-helical structure of the denatured state can bring together hydrophobic residues on the same sides of α-helices, making them available for intra- or intermolecular interactions. CPMG RD data analysis thus allowed a detailed structural characterization of the ADA2h denatured state under folding conditions not previously achieved for this protein.

  10. Carbon-13 nuclear magnetic resonance spectroscopy of lipids: Differential line broadening due to cross-correlation effects as a probe of membrane structure

    SciTech Connect

    Oldfield, E.; Adebodun, F.; Chung, J.; Montez, B.; Ki Deok Park; Hongbiao Le; Phillips, B. )

    1991-11-19

    The authors have obtained proton-coupled carbon-13 nuclear magnetic resonance (NMR) spectra of a variety of lipid-water and lipid-drug-water systems, at 11.7 T, as a function of temperature, using the 'magic-angle' sample-spinning (MAS) NMR technique. The resulting spectra show a wide range of line shapes, due to interferences between dipole-dipole and dipole-chemical shielding anisotropy interactions. The differential line-broadening effects observed are particularly large for aromatic and olefinic (sp{sup 2}) carbon atom sites. Coupled spectra of the tricyclic antidepressants desipramine and imipramine, in 1,2-dimyristoyl-sn-glycero-3-phosphocholine-water mesophases, show well-resolved doublets having different line shapes for each of the four aromatic methine groups, due to selective averaging of the four C-H dipolar interactions due to rapid motion about the director (or drug C{sub 2}) axis. {sup 2}H NMR spectra of (2,4,6,8-{sup 2}H{sub 4})desipramine (and imipramine) in the same 1,2-dimyristoyl-sn-glycero-3-phosphocholine-water mesophase exhibit quadrupole splittings of {approximately}0-2 and {approximately}20 kHz, indicating an approximate magic-angle orientation of the C2-{sup 2}H({sup 1}H) and C8-{sup 2}H({sup 1}H) vectors with respect to an axis of motional averaging, in accord with the {sup 13}C NMR results. The good qualitative agreement between {sup 13}C and {sup 2}H NMR results suggests that useful orientational ({sup 2}H NMR like) information can be deduced from natural-abundance {sup 13}C NMR spectra of a variety of mobile solids.

  11. Probing the molecular architecture of Arabidopsis thaliana secondary cell walls using two- and three-dimensional (13)C solid state nuclear magnetic resonance spectroscopy.

    PubMed

    Dupree, Ray; Simmons, Thomas J; Mortimer, Jennifer C; Patel, Dharmesh; Iuga, Dinu; Brown, Steven P; Dupree, Paul

    2015-04-14

    The plant secondary cell wall is a thickened polysaccharide and phenolic structure, providing mechanical strength to cells, particularly in woody tissues. It is the main feedstock for the developing bioenergy and green chemistry industries. Despite the role that molecular architecture (the arrangement of biopolymers relative to each other, and their conformations) plays in dictating biomass properties, such as recalcitrance to breakdown, it is poorly understood. Here, unprocessed dry (13)C-labeled stems from the model plant Arabidopsis thaliana were analyzed by a variety of (13)C solid state magic angle spinning nuclear magnetic resonance methods, such as one-dimensional cross-polarization and direct polarization, two-dimensional refocused INADEQUATE, RFDR, PDSD, and three-dimensional DARR, demonstrating their viability for the study of native polymer arrangements in intact secondary cell walls. All carbon sites of the two main glucose environments in cellulose (previously assigned to microfibril surface and interior residues) are clearly resolved, as are carbon sites of the other major components of the secondary cell wall: xylan and lignin. The xylan carbon 4 chemical shift is markedly different from that reported previously for solution or primary cell wall xylan, indicating significant changes in the helical conformation in these dried stems. Furthermore, the shift span indicates that xylan adopts a wide range of conformations in this material, with very little in the 31 conformation typical of xylan in solution. Additionally, spatial connections of noncarbohydrate species were observed with both cellulose peaks conventionally assigned as "surface" and as "interior" cellulose environments, raising questions about the origin of these two cellulose signals.

  12. Status of the SPES project, a new tool for fundamental and apply science studies with exotic ion beams at LNL

    NASA Astrophysics Data System (ADS)

    Napoli, D. R.; Andrighetto, A.; Antonini, P.; Bellan, L.; Bellato, M.; Benini, D.; Bermudez, J.; Bisoffi, G.; Boratto, E.; Bortolato, D.; Calabretta, L.; Calderolla, M.; Calore, A.; Campo, D.; Carturan, S.; Cinausero, M.; Comunian, M.; Corradetti, S.; De Angelis, G.; De Ruvo, P. L.; Esposito, J.; Ferrari, L.; Galatá, A.; Gelain, F.; Giacchini, M.; Giacomazzi, P.; Gobbi, C.; Gramegna, F.; Gulmini, M.; Lollo, M.; Lombardi, A.; Maggiore, M.; Manzolaro, M.; Michinelli, R.; Modanese, P.; Moisio, M. F.; Monetti, A.; Mozzi, A.; Palmieri, A.; Pasquato, F.; Pedretti, D.; Pegoraro, R.; Pisent, A.; Poggi, M.; Pranovi, L.; Prete, G.; Roncolato, C.; Rossignoli, M.; Russo, A. D.; Sarchiapone, L.; Scarpa, D.; Silingardi, R.; Dobon, J. J. Valiente; Visentin, E.; Vivian, G.; Zafiropoulos, D.; Prete, G. F.

    2016-07-01

    SPES, a new accelerator facility for both the production of exotic ion beams and radio-pharmaceuticals, is presently being installed at the Laboratori Nazionali di Legnaro in Italy (LNL). The new cyclotron, which will provide high intensity proton beams for the production of the rare isotopes, has been installed and is now in the commissioning phase. We present here the status of the part of the project devoted to the production and acceleration of fission fragments created in the interaction of an intense proton beam on a production target of UCx. The expected SPES radioactive beams intensities, their quality and their maximum energies (up to 11 MeV/A for A=130) will permit to perform forefront research in nuclear structure and nuclear dynamics far from the stability valley. Another low energy section of the facility is foreseen for new and challenging research, both in the nuclear physics and in the material science frameworks.

  13. Implementation of Akiyama probe in low temperature magnetic force microscope

    NASA Astrophysics Data System (ADS)

    Sass, Paul; Wu, Weida

    Exotic phenomena often call for high sensitivity scanning probe microscopic techniques working at extremely low temperatures. Specifically, it is of great fundamental interest to detect the weak magnetic signals in a range of interesting systems such as, quantum anomalous Hall, skyrmion, heavy-fermion, and multiferroic systems. To this end, we are developing low temperature magnetic force microscope (MFM) using a self-sensing cantilever called Akiyama-probe (A-probe). The main advantage of this specific probe is its extremely low power-dissipation compared to other self-sensing (e.g. piezoresistive) cantilevers for low temperature application. We will present progress of the implementation of A-probe and preliminary results under various conditions. This work is supported by DOE BES under Award DE-SC0008147.

  14. Characterisation of ectomycorrhizal formation by the exotic fungus Amanita muscaria with Nothofagus cunninghamii in Victoria, Australia.

    PubMed

    Dunk, Christopher William; Lebel, Teresa; Keane, Philip J

    2012-02-01

    The occurrence of the exotic ectomycorrhizal fungus Amanita muscaria in a mixed Nothofagus-Eucalyptus native forest was investigated to determine if A. muscaria has switched hosts to form a successful association with a native tree species in a natural environment. A mycorrhizal morphotype consistently found beneath A. muscaria sporocarps was examined, and a range of morphological and anatomical characteristics in common with those described for ectomycorrhizae formed by A. muscaria on a broad range of hosts were observed. A full description is provided. The likely plant associate was determined to be Nothofagus cunninghamii based upon anatomy of the roots. Analysis of ITS-1 and ITS-2 regions of nuclear ribosomal DNA sequences confirmed the identities of both fungal and plant associates. These findings represent conclusive evidence of the invasion of a non-indigenous ectomycorrhizal fungus into native forest and highlight the ecological implications of this discovery.

  15. A new plunger device to measure lifetimes of unbound states in tagged exotic nuclei

    NASA Astrophysics Data System (ADS)

    Taylor, M. J.; Cullen, D. M.; Procter, M. G.; Smith, A. J.; Twist, V.; Jones, P. M.; Nieminen, P.; Grahn, T.; Butler, P. A.; Scheck, M.

    2012-09-01

    A new plunger device has been designed and is being built at the University of Manchester to measure lifetimes of unbound states in exotic nuclei approaching the proton drip-line. The device is designed to work in both vacuum and gas environments and will be used in conjunction with the gas filled separator RITU and the vacuum-mode separator MARA at the University of Jyväskylä, Finland. This will enable the accurate measurement of excited state lifetimes identified via isomer and charged-particle tagging. The plunger will be used to address many key facets of nuclear structure physics with particular emphasis on the effect of deformation on proton emission rates.

  16. Model of an exotic chiral superconducting phase in a graphene bilayer.

    PubMed

    Hosseini, Mir Vahid; Zareyan, Malek

    2012-04-06

    We theoretically demonstrate the formation of a new type of unconventional superconductivity in graphene materials, which exhibits a gapless property. The studied superconductivity is based on an interlayer pairing of chiral electrons in bilayer graphene, which results in an exotic s-wave spin-triplet condensate order with anomalous thermodynamic properties. These include the possibility of a temperature-induced condensation causing an increase of the pairing gap with increasing temperature and an entropy of the stable superconducting state which can be higher than its value in the normal state. Our study reveals the analogy of the interlayer superconductivity in graphene materials to the color superconductivity in dense quark matter and the gapless pairing states in nuclear matter and ultracold atomic gases.

  17. Atomic scale structure of amorphous aluminum oxyhydroxide, oxide and oxycarbide films probed by very high field (27)Al nuclear magnetic resonance.

    PubMed

    Baggetto, L; Sarou-Kanian, V; Florian, P; Gleizes, A N; Massiot, D; Vahlas, C

    2017-03-15

    The atomic scale structure of aluminum in amorphous alumina films processed by direct liquid injection chemical vapor deposition from aluminum tri-isopropoxide (ATI) and dimethyl isopropoxide (DMAI) is investigated by solid-state (27)Al nuclear magnetic resonance (SSNMR) using a very high magnetic field of 20.0 T. This study is performed as a function of the deposition temperature in the range 300-560 °C, 150-450 °C, and 500-700 °C, for the films processed from ATI, DMAI (+H2O), and DMAI (+O2), respectively. While the majority of the films are composed of stoichiometric aluminum oxide, other samples are partially or fully hydroxylated at low temperature, or contain carbidic carbon when processed from DMAI above 500 °C. The quantitative analysis of the SSNMR experiments reveals that the local structure of these films is built from AlO4, AlO5, AlO6 and Al(O,C)4 units with minor proportions of the 6-fold aluminum coordination and significant amounts of oxycarbides in the films processed from DMAI (+O2). The aluminum coordination distribution as well as the chemical shift distribution indicate that the films processed from DMAI present a higher degree of structural disorder compared to the films processed from ATI. Hydroxylation leads to an increase of the 6-fold coordination resulting from the trend of OH groups to integrate into AlO6 units. The evidence of an additional environment in films processed from DMAI (+O2) by (27)Al SSNMR and first-principle NMR calculations on Al4C3 and Al4O4C crystal structures supports that carbon is located in Al(O,C)4 units. The concentration of this coordination environment strongly increases with increasing process temperature from 600 to 700 °C favoring a highly disordered structure and preventing from crystallizing into γ-alumina. The obtained results are a valuable guide to the selection of process conditions for the CVD of amorphous alumina films with regard to targeted applications.

  18. Pollution Probe.

    ERIC Educational Resources Information Center

    Chant, Donald A.

    This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

  19. Predicting invasion in grassland ecosystems: is exotic dominance the real embarrassment of richness?

    USGS Publications Warehouse

    Seabloom, Eric; Borer, Elizabeth; Buckley, Yvonne; Cleland, Elsa E.; Davies, Kendi; Firn, Jennifer; Harpole, W. Stanley; Hautier, Yann; Lind, Eric M.; MacDougall, Andrew; Orrock, John L.; Prober, Suzanne M.; Adler, Peter; Alberti, Juan; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Blumenthal, Dana; Brown, Cynthia S.; Brudvig, Lars A.; Caldeira, Maria; Chu, Cheng-Jin; Crawley, Michael J.; Daleo, Pedro; Damschen, Ellen Ingman; D'Antonio, Carla M.; DeCrappeo, Nicole M.; Dickman, Chris R.; Du, Guozhen; Fay, Philip A.; Frater, Paul; Gruner, Daniel S.; Hagenah, Nicole; Hector, Andrew; Helm, Aveliina; Hillebrand, Helmut; Hofmockel, Kirsten S.; Humphries, Hope C.; Iribarne, Oscar; Jin, Virginia L.; Kay, Adam; Kirkman, Kevin P.; Klein, Julia A.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Ladwig, Laura M.; ,; John, G.; Leakey, Andrew D.B.; Li, Qi; Li, Wei; McCulley, Rebecca; Melbourne, Brett; ,; Charles, E.; Moore, Joslin L.; Morgan, John; Mortensen, Brent; O'Halloran, Lydia R.; Pärtel, Meelis; Pascual, Jesús; Pyke, David A.; Risch, Anita C.; Salguero-Gómez, Roberto; Sankaran, Mahesh; Schuetz, Martin; Simonsen, Anna; Smith, Melinda; Stevens, Carly; Sullivan, Lauren; Wardle, Glenda M.; Wolkovich, Elizabeth M.; Wragg, Peter D.; Wright, Justin; Yang, Louie

    2013-01-01

    Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring

  20. Predicting invasion in grassland ecosystems: is exotic dominance the real embarrassment of richness?

    SciTech Connect

    Seabloom, Eric W.

    2013-08-14

    Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring

  1. Regional collaborative research on cold tolerance of exotic biofuel grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold tolerance is a selectable trait for many exotic grasses, even those of tropical or subtropical origin. We are conducting cold tolerance assessments on an array of perennial biofuel grasses at Booneville, AR. In study one (published), we reported that two sugarcane clones (US84-1028 and US84-1...

  2. Florida exotic whitefly invaders from the last decade

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The state of Florida hosts a large number of exotic species with many new “invasives” arriving annually. Among invasive insects establishing in Florida over the past decade are three whiteflies (Hemiptera: Aleyrodidae) that cause highly visible wax and sooty mold buildup in urban plantings as well a...

  3. Children prioritize virtual exotic biodiversity over local biodiversity.

    PubMed

    Ballouard, Jean-Marie; Brischoux, François; Bonnet, Xavier

    2011-01-01

    Environmental education is essential to stem current dramatic biodiversity loss, and childhood is considered as the key period for developing awareness and positive attitudes toward nature. Children are strongly influenced by the media, notably the internet, about biodiversity and conservation issues. However, most media focus on a few iconic, appealing, and usually exotic species. In addition, virtual activities are replacing field experiences. This situation may curb children knowledge and concerns about local biodiversity. Focusing our analyses on local versus exotic species, we examined the level of knowledge and the level of diversity of the animals that French schoolchildren are willing to protect, and whether these perceptions are mainly guided by information available in the internet. For that, we collected and compared two complementary data sets: 1) a questionnaire was administered to schoolchildren to assess their knowledge and consideration to protect animals, 2) an internet content analysis (i.e. Google searching sessions using keywords) was performed to assess which animals are the most often represented. Our results suggest that the knowledge of children and their consideration to protect animal are mainly limited to internet contents, represented by a few exotic and charismatic species. The identification rate of local animals by schoolchildren was meager, suggesting a worrying disconnection from their local environment. Schoolchildren were more prone to protect "virtual" (unseen, exotic) rather than local animal species. Our results reinforce the message that environmental education must also focus on outdoor activities to develop conservation consciousness and concerns about local biodiversity.

  4. Children Prioritize Virtual Exotic Biodiversity over Local Biodiversity

    PubMed Central

    Ballouard, Jean-Marie; Brischoux, François; Bonnet, Xavier

    2011-01-01

    Environmental education is essential to stem current dramatic biodiversity loss, and childhood is considered as the key period for developing awareness and positive attitudes toward nature. Children are strongly influenced by the media, notably the internet, about biodiversity and conservation issues. However, most media focus on a few iconic, appealing, and usually exotic species. In addition, virtual activities are replacing field experiences. This situation may curb children knowledge and concerns about local biodiversity. Focusing our analyses on local versus exotic species, we examined the level of knowledge and the level of diversity of the animals that French schoolchildren are willing to protect, and whether these perceptions are mainly guided by information available in the internet. For that, we collected and compared two complementary data sets: 1) a questionnaire was administered to schoolchildren to assess their knowledge and consideration to protect animals, 2) an internet content analysis (i.e. Google searching sessions using keywords) was performed to assess which animals are the most often represented. Our results suggest that the knowledge of children and their consideration to protect animal are mainly limited to internet contents, represented by a few exotic and charismatic species. The identification rate of local animals by schoolchildren was meager, suggesting a worrying disconnection from their local environment. Schoolchildren were more prone to protect “virtual” (unseen, exotic) rather than local animal species. Our results reinforce the message that environmental education must also focus on outdoor activities to develop conservation consciousness and concerns about local biodiversity. PMID:21829710

  5. Phenology of exotic invasive weeds associated with downy brome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The exotic and highly invasive annual grass downy brome (Bromus tectorum) has invaded millions of hectares of rangelands throughout the Intermountain West. Downy brome increases the chance, rate, season and spread of wildfires, resulting in the destruction of native plant communities and the wildli...

  6. Search for JPC=1-+ exotic state in e +e- annihilation

    NASA Astrophysics Data System (ADS)

    Wang, Qian

    2014-06-01

    The P-wave and S-wave heavy-light mesons and their charge conjugates, i.e., D1(2420)D¯+c .c., D1(2420)D¯*+c .c., and D2(2460)D¯*+c .c., can couple to states with vector quantum number JPC=1-- and exotic quantum number JPC=1-+ in a relative S wave. Near threshold, the heavy-light meson pair may form hadronic molecules due to the strong S-wave coupling, and the mysterious vector state Y(4260) could be such a state of the D1(2420)D¯+c .c. molecule. This implies the possible existence of its conjugate partner made of the same heavy-light mesons but with exotic quantum number JPC=1-+. We evaluate the production rate of such exotic hadronic molecules and propose a direct experimental search for them in e +e- annihilation. Confirmation of such exotic states in experiment will certainly deepen our insights into strong QCD and the arrangement of multiquark degrees of freedom.

  7. Risk of exotic annual grass-fire cycle in Goose Creek milkvetch habitat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a concern that habitats surrounding Goose Creek milkvetch populations are at risk of exotic annual grass invasion leading to an exotic annual grass-fire cycle. We sampled plant community and site characteristics to evaluate the risk of these habitats developing an exotic annual grass-fire ...

  8. Exotic Leptons. Higgs, Flavor and Collider Phenomenology

    DOE PAGES

    Altmannshofer, Wolfgang; Bauer, Martin; Carena, Marcela

    2014-01-15

    We study extensions of the standard model by one generation of vector-like leptons with non-standard hypercharges, which allow for a sizable modification of the h → γγ decay rate for new lepton masses in the 300 GeV-1 TeV range. We also analyze vacuum stability implications for different hypercharges. Effects in h → Zγ are typically much smaller than in h → γγ, but distinct among the considered hypercharge assignments. Non-standard hypercharges constrain or entirely forbid possible mixing operators with standard model leptons. As a consequence, the leading contributions to the experimentally strongly constrained electric dipole moments of standard model fermionsmore » are only generated at the two loop level by the new CP violating sources of the considered setups. Furthermore, we derive the bounds from dipole moments, electro-weak precision observables and lepton flavor violating processes, and discuss their implications. Finally, we examine the production and decay channels of the vector-like leptons at the LHC, and find that signatures with multiple light leptons or taus are already probing interesting regions of parameter space.« less

  9. Exotic Leptons. Higgs, Flavor and Collider Phenomenology

    SciTech Connect

    Altmannshofer, Wolfgang; Bauer, Martin; Carena, Marcela

    2014-01-15

    We study extensions of the standard model by one generation of vector-like leptons with non-standard hypercharges, which allow for a sizable modification of the h → γγ decay rate for new lepton masses in the 300 GeV-1 TeV range. We also analyze vacuum stability implications for different hypercharges. Effects in h → Zγ are typically much smaller than in h → γγ, but distinct among the considered hypercharge assignments. Non-standard hypercharges constrain or entirely forbid possible mixing operators with standard model leptons. As a consequence, the leading contributions to the experimentally strongly constrained electric dipole moments of standard model fermions are only generated at the two loop level by the new CP violating sources of the considered setups. Furthermore, we derive the bounds from dipole moments, electro-weak precision observables and lepton flavor violating processes, and discuss their implications. Finally, we examine the production and decay channels of the vector-like leptons at the LHC, and find that signatures with multiple light leptons or taus are already probing interesting regions of parameter space.

  10. Mirrored Fragmentation Reactions--A New Technique for Probing Isospin Symmetry in Exotic Nuclei

    SciTech Connect

    Brown, J. R.; Bentley, M. A.; Taylor, M. J.; Aldrich, P.; Bazin, D.; Cook, J. M.; Diget, C. A.; Gade, A.; Glasmacher, T.; McDaniel, S. M.; Ratkiewicz, A.; Siwek, K.; Weisshaar, D.; Pritychenko, B.

    2008-05-12

    Gamma decays have been observed for the first time in the T{sub z} = -3/2 nucleus {sup 53}Ni. This represents the first gamma-spectroscopy of a T{sub z} = -3/2 nucleus heavier than A = 33. The nucleus was produced via a two-step fragmentation process, along with its mirror {sup 53}Mn. Differences in excitation energy between isobaric analogue states have been calculated and a preliminary interpretation attempted; shell model calculations are required to further understand these results. This work represents the first study of isobaric analogue states via mirrored fragmentation reactions and demonstrates the power of this new technique.

  11. Exotic gravitational microlensing effects as a probe of stellar and galactic structure

    NASA Astrophysics Data System (ADS)

    Becker, Andrew Cameron

    The nature of the "dark matter" which comprises the majority of the mass of our Universe is one of the most elusive, yet fundamental, cosmological properties. Its presence has been inferred on a variety of scales by indirect observational measurements. It remains to be seen whether or not this dark matter is composed of discrete units (Machos---Massive Compact Halo Objects) or is a sea of fundamental particles (WIMPS---Weakly Interacting Massive Particles). The MACHO project was founded to test for Machos orbiting in the halo of our Milky Way Galaxy. The experiment makes use of the one property we know about dark matter---it exerts a gravitational force on its surroundings. Einstein's theory of general relativity implies the region of influence sensitive to dark matter includes the fundamental fabric of space-time itself. A bizarre consequence of this is that matter may warp space, splitting the light from a background source into multiple images on the sky, hence acting as a gravitational lens. Millions of source stars in the Large and Small Magellanic Clouds have been observed for signatures of intervening, lensing dark matter. Approximately 20 events have been discovered. Several hundred additional events have been seen towards our Galactic bulge. Given the dearth of lensing events, the focus of the gravitational microlensing field has evolved from passive surveys to an aggressive pursuit of lightcurve fine structure. Embedded in each microlensing lightcurve are clues to the nature of the lensing system. Recognizing these features in real-time requires frequent sampling and high precision measurements. This dissertation includes the development and maintenance of the MACHO Alert System, which recognized these rare events in real-time. This Alert System required daily vigilance between its inception in 1995 and the completion of the MACHO Survey in 1999. However, the focus of this dissertation was the Global Microlensing Alert Network (GMAN). This system comprises telescopes in Australia, Chile, Israel, and New Zealand. These resources were reallocated in real-time to provide maximum sensitivity to lightcurve fine-structure. The nightly scheduling of targets, real-time reduction of tens of thousands of astronomical images, and final analysis of the ensemble of events are the focus of this dissertation.

  12. FOREWORD: Nuclear Physics in Astrophysics V

    NASA Astrophysics Data System (ADS)

    Auerbach, Naftali; Hass, Michael; Paul, Michael

    2012-02-01

    the conference dinner banquet at the Dan hotel. An excursion to the 'Red Canyon' in the Eilat Mountains on Wednesday afternoon was one of the social highlights of the conference. A total number of 140 scientists attended NPA5 and about 30 accompanying persons; about 25% of these were young participants (less than 36 years old). 23 participants were from Israel, and 27 were from outside of Europe (including two from Africa). The subjects covered at the conference in Eilat concentrated mainly on the spirit of the original idea - to probe experimental and theoretical activity in nuclear structure and reactions that is directly related to the physics of the Universe. There were also sessions of general interest in astrophysics, as well as a poster session on Tuesday evening featuring 40 posters. The topics included: Nuclear Structure - Theory and Experiment Big-Bang Nucleosynthesis and Formation of First Stars Stellar Reactions and Solar Neutrinos Explosive Nucleosynthesis, Radioactive Beams and Exotic Nuclei-New Facilities and Future Possibilities for Astrophysics Neutrino Physics - the Low and High-Energy Frontiers Rare events, Dark Matter, Double beta-decay, Symmetries The conference started with an excellent exposé of the progress made in the discovery of super-heavy elements and the study of their properties. The progress in this field is enormous, and this subject should be communicated to more general audiences. The role of the nuclear equation of state and of the precise determination of nuclear masses in nucleosynthesis was emphasized in several talks. The role of neutrinos in astrophysics was discussed extensively in several sessions. One of the highlights of this was the presentation about the IceCube and DeepCore detectors operating deep in the Antarctic ice. These facilities are able to detect cosmogenic neutrinos in a wide energy range, from 10 GeV to 1010 GeV. The subject of solar neutrinos was discussed in a number of talks. Topics related to properties

  13. Thermodynamics of Asymmetric Nuclear Material

    NASA Astrophysics Data System (ADS)

    McIntosh, Alan; Bonasera, A.; Cammarata, P. J.; Hagel, K.; Kohley, Z.; Heilborn, L.; Mabiala, J.; May, L. W.; Marini, P.; Raphelt, A.; Souliotis, G. A.; Wuenschel, S.; Zarrella, A.; Zheng, H.; Yennello, S. J.

    2013-10-01

    The nuclear caloric curve is observed to depend on the neutron-proton asymmetry. Three independent methods, each with multiple probes, are used to extract the temperatures of excited emitting sources. A linear decrease in the temperature with increasing neutron excess is observed for all 12 probes studied. Comparison of these results to theoretical model calculations may allow further characterization of the nuclear equation of state, in particular the asymmetry energy.

  14. Intermediate-energy nuclear chemistry workshop

    SciTech Connect

    Butler, G.W.; Giesler, G.C.; Liu, L.C.; Dropesky, B.J.; Knight, J.D.; Lucero, F.; Orth, C.J.

    1981-05-01

    This report contains the proceedings of the LAMPF Intermediate-Energy Nuclear Chemistry Workshop held in Los Alamos, New Mexico, June 23-27, 1980. The first two days of the Workshop were devoted to invited review talks highlighting current experimental and theoretical research activities in intermediate-energy nuclear chemistry and physics. Working panels representing major topic areas carried out indepth appraisals of present research and formulated recommendations for future research directions. The major topic areas were Pion-Nucleus Reactions, Nucleon-Nucleus Reactions and Nuclei Far from Stability, Mesonic Atoms, Exotic Interactions, New Theoretical Approaches, and New Experimental Techniques and New Nuclear Chemistry Facilities.

  15. Excited and exotic charmonium spectroscopy from lattice QCD

    SciTech Connect

    Liuming Liu, Graham Moir, Michael Peardon, Sinead Ryan, Christopher Thomas, Pol Vilaseca, Jozef Dudek, Robert Edwards, Balint Joo, David Richards

    2012-07-01

    We present a spectrum of highly excited charmonium mesons up to around 4.5 GeV calculated using dynamical lattice QCD. Employing novel computational techniques and the variational method with a large basis of carefully constructed operators, we extract and reliably identify the continuum spin of an extensive set of excited states, states with exotic quantum numbers (0+-, 1-+, 2+-) and states with high spin. Calculations are performed on two lattice volumes with pion mass ? 400 MeV and the mass determinations have high statistical precision even for excited states. We discuss the results in light of experimental observations, identify the lightest 'supermultiplet' of hybrid mesons and comment on the phenomenological implications of the spectrum of exotic mesons.

  16. Towards a Deeper Understanding of the Nucleus with Exotic Nuclei

    NASA Astrophysics Data System (ADS)

    Ormand, Erich

    2006-10-01

    Despite more than fifty years of study, many questions about now nuclei are put together remain. While nuclei near the valley of stability have provided a wealth of information, they are not sufficient to provide us with a comprehensive and unified description of the nucleus. Especially lacking is an accurate picture of those exotic species that are the basis of cosmic alchemy. The missing pieces in the puzzle can be filled in with a determined experimental and theoretical effort focusing on nuclei lying far from the valley of stability. Here, I will outline the intellectual challenges that can be addressed by proposed exotic-beam facilities, and how new experimental data will quide and refine theoretical descriptions of the nucleus.

  17. Higgs Boson, Magnetic Monopoles and Exotic Smoothness in 4D

    NASA Astrophysics Data System (ADS)

    Asselmeyer-Maluga, Torsten; Król, Jerzy

    We present a model where three incompatible smoothness structures on open 4-manifolds are partly responsible for different physical effects, like: i. the appearance of magnetic matter and Higgs field as non-perturbative solutions of Yang-Mills theory, ii. in cosmology: the inflation, its speed, finite time of the acceleration and the Higgs mass, iii. the perturbative quantum matter as in the standard model of particles. The corresponding 3 smoothness structures are: i. exotic {R}4s with its exotic end S3 × {R}, ii. the fake S3 × Θ (8_{10)}{R} of Freedman, iii. the standard {R}4. It is conjectured that the issue of quantum gravity relies on the incompatibility of the structures.

  18. Hadron Spectroscopy, exotics and BC + physics at LHCb

    NASA Astrophysics Data System (ADS)

    Dey, Biplab

    2016-11-01

    The LHCb experiment is designed to study properties and decays of heavy flavored hadrons produced from pp collisions at the LHC. During Run 1, it has recorded the world's largest data sample of beauty and charm hadrons, enabling precision spectroscopy studies of such particles. Several important results obtained by LHCb, such as the discovery of the first pentaquark states and the first unambiguous determination of the Zc (4430) - as an exotic state, have dramatically increased the interest in spectroscopy of heavy hadrons. An overview of the latest LHCb results on the subject, including the discovery of four strange exotic states decaying as X → J/ψϕ, is presented. LHCb has also made significant contributions to the field of BC + physics, the lowest bound state of the heavy flavor ̅b and c quarks. A synopsis of the latest results is given.

  19. Distributions of exotic plants in eastern Asia and North America.

    PubMed

    Guo, Qinfeng; Qian, Hong; Ricklefs, Robert E; Xi, Weimin

    2006-07-01

    Although some plant traits have been linked to invasion success, the possible effects of regional factors, such as diversity, habitat suitability, and human activity are not well understood. Each of these mechanisms predicts a different pattern of distribution at the regional scale. Thus, where climate and soils are similar, predictions based on regional hypotheses for invasion success can be tested by comparisons of distributions in the source and receiving regions. Here, we analyse the native and alien geographic ranges of all 1567 plant species that have been introduced between eastern Asia and North America or have been introduced to both regions from elsewhere. The results reveal correlations between the spread of exotics and both the native species richness and transportation networks of recipient regions. This suggests that both species interactions and human-aided dispersal influence exotic distributions, although further work on the relative importance of these processes is needed.

  20. Distributions of exotic plants in eastern Asia and North America

    USGS Publications Warehouse

    Guo, Q.; Qian, H.; Ricklefs, R.E.; Xi, W.

    2006-01-01

    Although some plant traits have been linked to invasion success, the possible effects of regional factors, such as diversity, habitat suitability, and human activity are not well understood. Each of these mechanisms predicts a different pattern of distribution at the regional scale. Thus, where climate and soils are similar, predictions based on regional hypotheses for invasion success can be tested by comparisons of distributions in the source and receiving regions. Here, we analyse the native and alien geographic ranges of all 1567 plant species that have been introduced between eastern Asia and North America or have been introduced to both regions from elsewhere. The results reveal correlations between the spread of exotics and both the native species richness and transportation networks of recipient regions. This suggests that both species interactions and human-aided dispersal influence exotic distributions, although further work on the relative importance of these processes is needed. ?? 2006 Blackwell Publishing Ltd/CNRS.

  1. Nuclear Mass Measurement and Evaluation Relevant to Astrophysics

    NASA Astrophysics Data System (ADS)

    Wang, Meng

    Nuclear mass data are crucial input for the astrophysics models. Thanks to the developments of radioactive nuclear beam facilities and novel mass spectrometers, the experimental knowledge of nuclear masses has been continuously expanding to the exotic nuclei far from the stability which play a critical role in astrophysics. The recent progress and future perspective of mass measurement relevant to astrophysics will be discussed. By evaluating all available experimental data from nuclear reactions, radioactive decays and direct mass measurements, the Atomic Mass Evaluation (AME) serve the research community with reliable source for comprehensive information related to the nuclear masses. The next AME version is envisioned to be published at the end of 2016.

  2. Search for the Exotic Wobbling Mode in Rhenium-171

    DTIC Science & Technology

    2011-05-13

    by A NSI Std. Z39. 18 U.S.N.A. --- Trident Scholar project report; no. 400 (2011) SEARCH FOR THE EXOTIC WOBBLING MODE IN 171Re by...construct the level scheme of γ-ray transitions; the spins of the states must be determined. γ rays are electromagnetic radiation , and in level schemes...they have a change in spin of two and no change in parity. Based on the shape of each radiation pattern (dumbbell shaped for dipole transitions

  3. Exotic orientifolds in non-geometric flux cosmology

    SciTech Connect

    Damian, Cesar; Loaiza-Brito, Oscar

    2013-07-23

    We report on the existence of a stable de Sitter vacum in Type IIB non-geometric string compactification on an isotropic tours with orientifold 3-planes in the presence of odd integer 3-form fluxes. These fluxes yields the presence of exotic orientifold 3-planes increasing the size of the flux configuration space. We also find that there exist suitable conditions for multi-field inflation driven by the Kähler and axio-dilaton moduli.

  4. Global trade in exotic pets 2006-2012.

    PubMed

    Bush, Emma R; Baker, Sandra E; Macdonald, David W

    2014-06-01

    International trade in exotic pets is an important and increasing driver of biodiversity loss and often compromises the standards required for good animal welfare. We systematically reviewed the scientific and gray literature and used the United Nations Environment Programme - World Conservation Monitoring Centre (UNEP-WCMC) Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) trade database to establish temporal and geographical trade patterns of live exotic birds, mammals, and reptiles and to describe trends in research, taxonomic representation, and level of threat and legal protection of species traded. Birds were the most species-rich and abundant class reported in trade; reptiles were second most abundant but unusually the most studied in this context; and mammals were least abundant in trade. Mammalian and reptilian species traded as pets were more likely to be threatened than expected by random. There have been a substantial number of Appendix I listed captive-bred mammals and birds and wild-caught birds and reptiles reported in trade to CITES. We identified the Middle East's emerging role as a driver of demand for exotic pets of all taxa alongside the well-established and increasing role of South America and Southeast Asia in the market. Europe, North America, and the Middle East featured most heavily in trade reports to CITES, whereas trade involving South America and Southeast Asia were given most emphasis in the literature. For effective monitoring of and appropriate response to the international exotic pet trade, it is imperative that the reliability and detail of CITES trade reports improve and that scientific research be directed toward those taxa and locations that are most vulnerable.

  5. Pathology of the exotic companion mammal gastrointestinal system.

    PubMed

    Reavill, Drury

    2014-05-01

    A variety of disease agents can affect the gastrointestinal tract of the exotic companion mammal, some of which can pose zoonotic health concerns. Many conditions present with nonspecific clinical signs (lethargy, variable degrees of diarrhea, and for most sick rodents, presenting hunched with spiky fur), necessitating additional laboratory testing to reach a diagnosis. Primary tumors of the digestive tract are also presented as well as miscellaneous conditions ranging from toxins to trauma.

  6. Parameters of Density Distribution of Exotic Nuclei Extracted from a Data on Reaction Cross-section in the Glauber Model

    NASA Astrophysics Data System (ADS)

    Novikov, Ivan; Rueter, Keiti

    2016-09-01

    Parameters of density distribution of exotic nuclei with halo structure were extracted from the experimental data on the interaction cross-section using exact expressions obtained in the Glauber theory. Generally, to do so measured interaction cross-section is compared with a reaction cross-section calculated in optical approximation or using exact expressions of the Glauber theory. It was shown before that the parameters of nuclear density distribution depends on chosen density model (Gaussian, harmonic oscillator or Woods-Saxon) and on the used approximation of the Glauber theory (i.e. optical or rigid target). In the presented paper, we discuss the difference between reaction and interaction cross-sections calculated in various approximations, and how this difference affects the accuracy of the nuclear density parameters determination. As an example, we provide results of the analyzes of experimental data on interaction cross-section of 11Li, 16C and 31Ne nuclei on 12C target.

  7. Apparent competition with an exotic plant reduces native plant establishment.

    PubMed

    Orrock, John L; Witter, Martha S; Reichman, O J

    2008-04-01

    Biological invasions can change ecosystem function, have tremendous economic costs, and impact human health; understanding the forces that cause and maintain biological invasions is thus of immediate importance. A mechanism by which exotic plants might displace native plants is by increasing the pressure of native consumers on native plants, a form of indirect interaction termed "apparent competition." Using experimental exclosures, seed addition, and monitoring of small mammals in a California grassland, we examined whether exotic Brassica nigra increases the pressure of native consumers on a native bunchgrass, Nassella pulchra. Experimental plots were weeded to focus entirely on indirect effects via consumers. We demonstrate that B. nigra alters the activity of native small-mammal consumers, creating a gradient of consumption that dramatically reduces N. pulchra establishment. Previous work has shown that N. pulchra is a strong competitor, but that it is heavily seed limited. By demonstrating that consumer pressure is sufficient to curtail establishment, our work provides a mechanism for this seed limitation and suggests that, despite being a good competitor, N. pulchra cannot reestablish close to B. nigra within its old habitats because exotic-mediated consumption preempts direct competitive exclusion. Moreover, we find that apparent competition has a spatial extent, suggesting that consumers may dictate the rate of invasion and the area available for restoration, and that nonspatial studies of apparent competition may miss important dynamics.

  8. Fatalities due to indigenous and exotic species in Florida.

    PubMed

    Wolf, Barbara C; Harding, Brett E

    2014-01-01

    Florida's climate is suitable for many potentially hazardous animals, including both indigenous and exotic species, which are frequently kept as in zoos or as pets. This has resulted in many unforeseen fatal encounters between animals and the ever expanding human population. While the literature and knowledge pool for more common types of deaths referred to medical examiner/coroner's offices is abundant, the appreciation of wildlife and exotic pet-related deaths is far less widespread. We report seven animal attack-related deaths that occurred in Florida. The inflicted injuries included blunt and sharp force injuries, asphyxia, drowning, and envenomation. The underlying cause of death, however, was always a result of the human/animal interaction and in many cases related to human error and failure to appreciate the potentially dangerous behavior of nondomesticated species. These cases illustrate the varied circumstances and pathophysiologies associated with deaths due to indigenous and exotic species and the importance of the multidisciplinary approach in the medicolegal investigation of these cases.

  9. K isomers as probes of nuclear structure

    SciTech Connect

    Tandel, S. K.

    2014-08-14

    K isomers are studied in Pu and Cm isotopes, and also in Hf and W nuclei. Many high-K states, several of which are isomeric, are identified. Lifetime measurements spanning the ns-s range have been performed, and decay paths of isomers established. Rotational bands built on high-K states are also identified in many cases. Isomer decays are considerably hindered in many instances, both in the A≈180 and 250 regions indicating that K is an approximately conserved quantum number. High-K states become the favored excitation mode at high spins in the A≈180 region. The energies of the 2-quasiparticle high-K states in Cm isotopes suggest the presence of a deformed subshell gap at N=152.

  10. Habitat filtering by landscape and local forest composition in native and exotic New Zealand birds.

    PubMed

    Barnagaud, Jean-Yves; Barbaro, Luc; Papaïx, Julien; Deconchat, Marc; Brockerhoff, Eckehard G

    2014-01-01

    Untangling the relative influences of environmental filtering and biotic interactions on species coexistence at various spatial scales is a long-held issue in community ecology. Separating these processes is especially important to understand the influences of introduced exotic species on the composition of native communities. For this aim, we investigated coexistence patterns in New Zealand exotic and native birds along multiple-scale habitat gradients. We built a Bayesian hierarchical model, contrasting the abundance variations of 10 native and 11 exotic species in 501 point counts spread along landscape and local-scale gradients of forest structure and composition. Although native and exotic species both occurred in a wide range of habitats, they were separated by landscape-level variables. Exotic species were most abundant in exotic conifer plantations embedded in farmland matrices, while native birds predominated in areas dominated by continuous native forest. In exotic plantation forests, and to a lesser extent in native forests, locally co-occurring exotic and native species were segregated along a gradient of vegetation height. These results support the prediction that exotic and native bird species are segregated along gradients related to anthropogenic disturbance and habitat availability. In addition, native and exotic species overlapped little in a multivariate functional space based on 10 life history traits associated with habitat selection. Hence, habitat segregation patterns were probably mediated more by environmental filtering processes than by competition at landscape and local scales.

  11. Probing the Tautomerism of Histidine

    NASA Astrophysics Data System (ADS)

    Bermudez, C.; Cabezas, C.; Mata, S.; Alonso, J. L.

    2013-06-01

    The rotational spectrum of histidine, showing a complex nuclear quadrupole interactions arising from three ^{14}N nuclei in non-equivalent positions have been resolved and completely analyzed. Solid samples (m.p. 290°C) were vaporized by laser ablation and probed by Fourier transform microwave spectroscopy in a supersonic expansion. The experimental constants clearly lead to the unambiguous identification of the \\varepsilon tautomer in the gas phase.

  12. SUITABILITY OF A NEW CALORIMETER FOR EXOTIC MESON SEARCHES

    SciTech Connect

    Bookwalter, C.; Ostrovidov, A.; Eugenio, P.

    2007-01-01

    Exotic mesons, particles that have quantum numbers that are inaccessible to conventional quark-model mesons, are predicted by quantum chromodynamics (QCD), but past experiments seeking to identify exotic candidates have produced controversial results. The HyCLAS experiment (E04005) at Thomas Jefferson National Accelerator Facility (TJNAF) proposes the use of the Continuous Electron Beam Accelerator Facility (CEBAF) Large Acceptance Spectrometer (CLAS) in Hall B to study the photoproduction of exotic mesons. However, the base detector package at CLAS is not ideal for observing and measuring neutral particles, particularly at forward angles. The Deeply Virtual Compton Scattering (DVCS) experiment at TJNAF has commissioned a new calorimeter for detecting small-angle photons, but studies must be performed to determine its suitability for a meson spectroscopy experiment. The ηπ system has been under especial scrutiny in the community as a source for potential exotics, so the new calorimeter’s ability at reconstructing these resonances must be evaluated. To achieve this, the invariant mass of showers in the calorimeter are reconstructed. Also, two electroproduction reaction channels analogous to photoproduction channels of interest to HyCLAS are examined in DVCS data. It is found that, while not ideal, the new calorimeter will allow access to additional reaction channels, and its inclusion in HyCLAS is warranted. Results in basic shower reconstruction show that the calorimeter has good effi ciency in resolving π° decays, but its η reconstruction is not as strong. When examining ep → epπ°η, preliminary reconstruction of the ηπ° system shows faint signals in the a0(980) region. In the ep → e n π+ η channel, preliminary reconstruction of the ηπ+ system gave good signals in the a0(980) and a2(1320) regions, but statistics were poor. While more analyses are necessary to improve statistics and remove background, these preliminary results support the claim

  13. Potential Habitats for Exotic Life Within the Life Supporting Zone

    NASA Astrophysics Data System (ADS)

    Leitner, Johannes J.; Firneis, Maria G.; Hitzenberger, Regina

    2010-05-01

    Questions like "Are we alone in the universe?", "How unique is Earth as a planet?" or "How unique is water-based life in the universe?" still are nowhere near of being answered. In recent years, discussions on these topics are more and more influenced by questions whether water is really the only possible solvent, or which conditions are necessary for life to evolve in planetary habitats. A change in our present geocentric mindset on the existence of life is required, in order to address these new questions [see also 1]. In May 2009 a new research platform at the University of Vienna was initiated in order to contribute to the solution of these questions. One task is to find essential biomarkers relevant to the problem of the detection of exotic life. In this context exotic life means: life, which is not necessarily based on a double bond between carbon and oxygen (C=O) and not on water as the only possible solvent. At present little is known about metabolistic systems, which are not based on C=O or on metabolisms which are operative in alternative solvents and a high effort of future laboratory work is necessary to open this window for looking for exotic life. To address the whole spectrum of life the concept of a general life supporting zone is introduced in order to extend the classical habitable zone (which is based on liquid water on a planetary surface, [2]). The life supporting zone of a planetary system is composed of different single "habitable zones" for the liquid phases of specific solvents and composites between water and other solvents. Besides exoplanetary systems which seem to be the most promising place for exotic life in our present understanding, some potential places could also exist within our Solar System and habitats like the subsurface of Enceladus, liquid ethane/methane lakes on Titan or habitable niches in the Venus atmosphere will also be taken into account. A preliminary list of appropriate solvents and their abundances in the Solar

  14. The nuclear physics of neutron stars

    NASA Astrophysics Data System (ADS)

    Piekarewicz, J.

    2014-05-01

    We explore the unique and fascinating structure of neutron stars. Although neutron stars are of interest in many areas of Physics, our aim is to provide an intellectual bridge between Nuclear Physics and Astrophysics. We argue against the naive perception of a neutron star as a uniform assembly of neutrons packed to enormous densities. Rather, by focusing on the many exotic phases that are speculated to exist in a neutron star, we show how the reality is different and far more interesting.

  15. Are local filters blind to provenance? Ant seed predation suppresses exotic plants more than natives.

    PubMed

    Pearson, Dean E; Icasatti, Nadia S; Hierro, Jose L; Bird, Benjamin J

    2014-01-01

    The question of whether species' origins influence invasion outcomes has been a point of substantial debate in invasion ecology. Theoretically, colonization outcomes can be predicted based on how species' traits interact with community filters, a process presumably blind to species' origins. Yet, exotic plant introductions commonly result in monospecific plant densities not commonly seen in native assemblages, suggesting that exotic species may respond to community filters differently than natives. Here, we tested whether exotic and native species differed in their responses to a local community filter by examining how ant seed predation affected recruitment of eighteen native and exotic plant species in central Argentina. Ant seed predation proved to be an important local filter that strongly suppressed plant recruitment, but ants suppressed exotic recruitment far more than natives (89% of exotic species vs. 22% of natives). Seed size predicted ant impacts on recruitment independent of origins, with ant preference for smaller seeds resulting in smaller seeded plant species being heavily suppressed. The disproportionate effects of provenance arose because exotics had generally smaller seeds than natives. Exotics also exhibited greater emergence and earlier peak emergence than natives in the absence of ants. However, when ants had access to seeds, these potential advantages of exotics were negated due to the filtering bias against exotics. The differences in traits we observed between exotics and natives suggest that higher-order introduction filters or regional processes preselected for certain exotic traits that then interacted with the local seed predation filter. Our results suggest that the interactions between local filters and species traits can predict invasion outcomes, but understanding the role of provenance will require quantifying filtering processes at multiple hierarchical scales and evaluating interactions between filters.

  16. Native weeds and exotic plants: relationships to disturbance in mixed grass prairie

    USGS Publications Warehouse

    Larson, D.L.

    2003-01-01

    The paper compares distributions of native weedy species and exotic species with respect to three kinds of disturbance, roads, trails, and prairie dog towns. Data were collected at the north and south units of Theodore Roosevelt National Park and at Wind Cave National Park. The paper concludes that many exotic species differ substantially from native weeds in their exploitation of disturbance. It is thus not useful to manage exotics as if they were just another weed.

  17. Optical imaging probes in oncology

    PubMed Central

    Martelli, Cristina; Dico, Alessia Lo; Diceglie, Cecilia; Lucignani, Giovanni; Ottobrini, Luisa

    2016-01-01

    Cancer is a complex disease, characterized by alteration of different physiological molecular processes and cellular features. Keeping this in mind, the possibility of early identification and detection of specific tumor biomarkers by non-invasive approaches could improve early diagnosis and patient management. Different molecular imaging procedures provide powerful tools for detection and non-invasive characterization of oncological lesions. Clinical studies are mainly based on the use of computed tomography, nuclear-based imaging techniques and magnetic resonance imaging. Preclinical imaging in small animal models entails the use of dedicated instruments, and beyond the already cited imaging techniques, it includes also optical imaging studies. Optical imaging strategies are based on the use of luminescent or fluorescent reporter genes or injectable fluorescent or luminescent probes that provide the possibility to study tumor features even by means of fluorescence and luminescence imaging. Currently, most of these probes are used only in animal models, but the possibility of applying some of them also in the clinics is under evaluation. The importance of tumor imaging, the ease of use of optical imaging instruments, the commercial availability of a wide range of probes as well as the continuous description of newly developed probes, demonstrate the significance of these applications. The aim of this review is providing a complete description of the possible optical imaging procedures available for the non-invasive assessment of tumor features in oncological murine models. In particular, the characteristics of both commercially available and newly developed probes will be outlined and discussed. PMID:27145373

  18. Optical imaging probes in oncology.

    PubMed

    Martelli, Cristina; Lo Dico, Alessia; Diceglie, Cecilia; Lucignani, Giovanni; Ottobrini, Luisa

    2016-07-26

    Cancer is a complex disease, characterized by alteration of different physiological molecular processes and cellular features. Keeping this in mind, the possibility of early identification and detection of specific tumor biomarkers by non-invasive approaches could improve early diagnosis and patient management.Different molecular imaging procedures provide powerful tools for detection and non-invasive characterization of oncological lesions. Clinical studies are mainly based on the use of computed tomography, nuclear-based imaging techniques and magnetic resonance imaging. Preclinical imaging in small animal models entails the use of dedicated instruments, and beyond the already cited imaging techniques, it includes also optical imaging studies. Optical imaging strategies are based on the use of luminescent or fluorescent reporter genes or injectable fluorescent or luminescent probes that provide the possibility to study tumor features even by means of fluorescence and luminescence imaging. Currently, most of these probes are used only in animal models, but the possibility of applying some of them also in the clinics is under evaluation.The importance of tumor imaging, the ease of use of optical imaging instruments, the commercial availability of a wide range of probes as well as the continuous description of newly developed probes, demonstrate the significance of these applications. The aim of this review is providing a complete description of the possible optical imaging procedures available for the non-invasive assessment of tumor features in oncological murine models. In particular, the characteristics of both commercially available and newly developed probes will be outlined and discussed.

  19. Differential effectiveness of novel and old legume-rhizobia mutualisms: implications for invasion by exotic legumes.

    PubMed

    Rodríguez-Echeverría, Susana; Fajardo, Susana; Ruiz-Díez, Beatriz; Fernández-Pascual, Mercedes

    2012-09-01

    The degree of specialization in the legume-rhizobium mutualism and the variation in the response to different potential symbionts are crucial factors for understanding the process of invasion by exotic legumes and the consequences for the native resident plants and bacteria. The enhanced novel mutualism hypothesis predicts that exotic invasive legumes would take advantage of native rhizobia present in the invaded soils. However, recent studies have shown that exotic legumes might become invasive by using exotic introduced microsymbionts, and that they could be a source of exotic bacteria for native legumes. To unravel the role of novel and old symbioses in the progress of invasion, nodulation and symbiotic effectiveness were analyzed for exotic invasive plants and native co-occurring legumes in a Mediterranean coastal dune ecosystem. Although most of the studied species nodulated with bacteria from distant origins these novel mutualisms were less effective in terms of nodulation, nitrogenase activity and plant growth than the interactions of plants and bacteria from the same origin. The relative effect of exotic bradyrhizobia was strongly positive for exotic invasive legumes and detrimental for native shrubs. We conclude that (1) the studied invasive legumes do not rely on novel mutualisms but rather need the co-introduction of compatible symbionts, and (2) since exotic rhizobia colonize native legumes in invaded areas, the lack of effectiveness of these novel symbiosis demonstrated here suggests that invasion can disrupt native belowground mutualisms and reduce native legumes fitness.

  20. Core-satellite species hypothesis and native versus exotic species in secondary succession

    USGS Publications Warehouse

    Martinez, Kelsey A.; Gibson, David J.; Middleton, Beth A.

    2015-01-01

    A number of hypotheses exist to explain species’ distributions in a landscape, but these hypotheses are not frequently utilized to explain the differences in native and exotic species distributions. The core-satellite species (CSS) hypothesis predicts species occupancy will be bimodally distributed, i.e., many species will be common and many species will be rare, but does not explicitly consider exotic species distributions. The parallel dynamics (PD) hypothesis predicts that regional occurrence patterns of exotic species will be similar to native species. Together, the CSS and PD hypotheses may increase our understanding of exotic species’ distribution relative to natives. We selected an old field undergoing secondary succession to study the CSS and PD hypotheses in conjunction with each other. The ratio of exotic to native species (richness and abundance) was observed through 17 years of secondary succession. We predicted species would be bimodally distributed and that exotic:native species ratios would remain steady or decrease through time under frequent disturbance. In contrast to the CSS and PD hypotheses, native species occupancies were not bimodally distributed at the site, but exotic species were. The exotic:native species ratios for both richness (E:Nrichness) and abundance (E:Ncover) generally decreased or remained constant throughout supporting the PD hypothesis. Our results suggest exotic species exhibit metapopulation structure in old field landscapes, but that metapopulation structures of native species are disrupted, perhaps because these species are dispersal limited in the fragmented landscape.

  1. Exotic mosquito threats require strategic surveillance and response planning.

    PubMed

    Webb, Cameron E; Doggett, Stephen L

    2016-12-14

    Mosquito-borne diseases caused by endemic pathogens such as Ross River, Barmah Forest and Murray Valley encephalitis viruses are an annual concern in New South Wales (NSW), Australia. More than a dozen mosquito species have been implicated in the transmission of these pathogens, with each mosquito occupying a specialised ecological niche that influences their habitat associations, host feeding preferences and the environmental drivers of their abundance. The NSW Arbovirus Surveillance and Mosquito Monitoring Program provides an early warning system for potential outbreaks of mosquito-borne disease by tracking annual activity of these mosquitoes and their associated pathogens. Although the program will effectively track changes in local mosquito populations that may increase with a changing climate, urbanisation and wetland rehabilitation, it will be less effective with current surveillance methodologies at detecting or monitoring changes in exotic mosquito threats, where different surveillance strategies need to be used. Exotic container-inhabiting mosquitoes such as Aedes aegypti and Ae. albopictus pose a threat to NSW because they are nuisance-biting pests and vectors of pathogens such as dengue, chikungunya and Zika viruses. International movement of humans and their belongings have spread these mosquitoes to many regions of the world. In recent years, these two mosquitoes have been detected by the Australian Government Department of Agriculture and Water Resources at local airports and seaports. To target the detection of these exotic mosquitoes, new trapping technologies and networks of surveillance locations are required. Additionally, incursions of these mosquitoes into urban areas of the state will require strategic responses to minimise substantial public health and economic burdens to local communities.

  2. Galactic antiproton spectrum at high energies: Background expectation versus exotic contributions

    SciTech Connect

    Bringmann, Torsten; Salati, Pierre

    2007-04-15

    A new generation of upcoming space-based experiments will soon start to probe the spectrum of cosmic-ray antiparticles with an unprecedented accuracy and, in particular, will open up a window to energies much higher than those accessible so far. It is thus timely to carefully investigate the expected antiparticle fluxes at high energies. Here, we perform such an analysis for the case of antiprotons. We consider both standard sources as the collision of other cosmic rays with interstellar matter, as well as exotic contributions from dark matter annihilations in the galactic halo. Up to energies well above 100 GeV, we find that the background flux in antiprotons is almost uniquely determined by the existing low-energy data on various cosmic-ray species; for even higher energies, however, the uncertainties in the parameters of the underlying propagation model eventually become significant. We also show that if the dark matter is composed of particles with masses at the TeV scale, which is naturally expected in extra-dimensional models as well as in certain parameter regions of supersymmetric models, the annihilation flux can become comparable to--or even dominate--the antiproton background at the high energies considered here.

  3. Electron muon scattering in the exotic Z(0)' pole

    SciTech Connect

    Diaz, H.; Ravinez, O.; Romero, D.; Reyes, J.

    2009-04-30

    The search for new physics in the future Internacional Linear Collider ILC, implies the existence of new particles, among them, the Z(0)' particle. In this regard, we calculate the e{sup +}+e{sup -}{yields}{mu}{sup +}+{mu}{sup -} scattering cross section near the Z(0)' pole, whitin the contex of the SU(3){sub L}xU(1){sub Y} weak model, which contains exotic leptons, quarks, and bosons (E,J,U,V) with the finality of obtain constraints in the parameters of the model.

  4. Lake Michigan faces exotic species, dune sand mining, other challenges

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    As Steve Pothoven scooped out his bottom trawl catch on the deck of a U.S. government research vessel in June, he expected the regular monitoring exercise to land alewives and a mound of zebra mussels. These two now-ubiquitous exotic aquatic species are among more than 130 that have entered the Great Lakes ecosystem over the past century. They have invaded by various means: hiding in ballast water, navigating through connecting channels such as the Welland Canal that was completed in 1829 as a route around Niagara Falls, or introduced on purpose.

  5. Principles and Applications of Surgical Oncology in Exotic Animals.

    PubMed

    Steffey, Michele A

    2017-01-01

    The diagnosis and treatment of cancer in exotic species is a rapidly evolving area of veterinary medicine. In general, surgical excision remains pivotal in cancer treatment, although optimal outcomes are achieved when a coherent and thorough diagnostic and therapeutic plan is created prior to surgery. While surgical cure is not always achieveable, multimodal treatment plans can offer a variety of options, and palliative procedures may be used to improve quality of life. Treatment goals, whether curative intent or palliative intent, should be identified before surgery, and practitioners should endeavor to adhere to surgical principles in order to attain the best outcomes.

  6. Exotic Meson Decay to ωπ0π-

    NASA Astrophysics Data System (ADS)

    Lu, M.; Adams, G. S.; Adams, T.; Bar-Yam, Z.; Bishop, J. M.; Bodyagin, V. A.; Brown, D. S.; Cason, N. M.; Chung, S. U.; Cummings, J. P.; Danyo, K.; Demianov, A. I.; Denisov, S. P.; Dorofeev, V.; Dowd, J. P.; Eugenio, P.; Fan, X. L.; Gribushin, A. M.; Hackenburg, R. W.; Hayek, M.; Hu, J.; Ivanov, E. I.; Joffe, D.; Kachaev, I.; Kern, W.; King, E.; Kodolova, O. L.; Korotkikh, V. L.; Kostin, M. A.; Kuhn, J.; Lipaev, V. V.; Losecco, J. M.; Manak, J. J.; Nozar, M.; Olchanski, C.; Ostrovidov, A. I.; Pedlar, T. K.; Popov, A. V.; Ryabchikov, D. I.; Sarycheva, L. I.; Seth, K. K.; Shenhav, N.; Shen, X.; Shephard, W. D.; Sinev, N. B.; Stienike, D. L.; Suh, J. S.; Taegar, S. A.; Tomaradze, A.; Vardanyan, I. N.; Weygand, D. P.; White, D. B.; Willutzki, H. J.; Witkowski, M.; Yershov, A. A.

    2005-01-01

    A partial-wave analysis of the mesons from the reaction π-p→π+π-π-π0π0p has been performed. The data show b1π decay of the spin-exotic states π1(1600) and π1(2000). Three isovector 2-+ states were seen in the ωρ- decay channel. In addition to the well known π2(1670), signals were also observed for π2(1880) and π2(1970).

  7. Search for the exotic Θ+ resonance in the NOMAD experiment

    NASA Astrophysics Data System (ADS)

    Samoylov, O.; Naumov, D.; Cavasinni, V.; Astier, P.; Autiero, D.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Camilleri, L.; Cardini, A.; Cattaneo, P. W.; Cervera-Villanueva, A.; Challis, R.; Chukanov, A.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Daniels, D.; Degaudenzi, H.; Del Prete, T.; de Santo, A.; Dignan, T.; di Lella, L.; Do Couto E Silva, E.; Dumarchez, J.; Ellis, M.; Feldman, G. J.; Ferrari, R.; Ferrère, D.; Flaminio, V.; Fraternali, M.; Gaillard, J.-M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Gninenko, S.; Godley, A.; Gomez-Cadenas, J.-J.; Gosset, J.; Gößling, C.; Gouanère, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hubbard, D.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kent, N.; Kirsanov, M.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Lacaprara, S.; Lachaud, C.; Lakić, B.; Lanza, A.; La Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Levy, J.-M.; Linssen, L.; Ljubičić, A.; Long, J.; Lupi, A.; Lyubushkin, V.; Marchionni, A.; Martelli, F.; Méchain, X.; Mendiburu, J.-P.; Meyer, J.-P.; Mezzetto, M.; Mishra, S. R.; Moorhead, G. F.; Nédélec, P.; Nefedov, Y.; Nguyen-Mau, C.; Orestano, D.; Pastore, F.; Peak, L. S.; Pennacchio, E.; Pessard, H.; Petti, R.; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Poulsen, C.; Popov, B.; Rebuffi, L.; Rico, J.; Riemann, P.; Roda, C.; Rubbia, A.; Salvatore, F.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sconza, A.; Sevior, M.; Sillou, D.; Soler, F. J. P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipčević, M.; Stolarczyk, Th.; Tareb-Reyes, M.; Taylor, G. N.; Tereshchenko, V.; Toropin, A.; Touchard, A.-M.; Tovey, S. N.; Tran, M.-T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K. E.; Veltri, M.; Vercesi, V.; Vidal-Sitjes, G.; Vieira, J.-M.; Vinogradova, T.; Weber, F. V.; Weisse, T.; Wilson, F. F.; Winton, L. J.; Yabsley, B. D.; Zaccone, H.; Zuber, K.; Zuccon, P.

    2007-01-01

    A search for exotic Θ+ baryon via Θ+→p+K0 S decay mode in the NOMAD νμN data is reported. The special background generation procedure was developed. The proton identification criteria are tuned to maximize the sensitivity to the Θ+ signal as a function of xF which allows to study the Θ+ production mechanism. We do not observe any evidence for the Θ+ state in the NOMAD data. We provide an upper limit on Θ+ production rate at 90% CL as 2.13×10-3 per neutrino interaction.

  8. Exotic magnetic states in Pauli-limited superconductors.

    PubMed

    Kenzelmann, M

    2017-03-01

    Magnetism and superconductivity compete or interact in complex and intricate ways. Here we review the special case where novel magnetic phenomena appear due to superconductivity, but do not exist without it. Such states have recently been identified in unconventional superconductors. They are different from the mere coexistence of magnetic order and superconductivity in conventional superconductors, or from competing magnetic and superconducting phases in many materials. We describe the recent progress in the study of such exotic magnetic phases, and articulate the many open questions in this field.

  9. Small exotic companion mammal wellness management and environmental enrichment.

    PubMed

    Pilny, Anthony A

    2015-05-01

    Wellness management and environmental enrichment are important components of preventative veterinary medical care. Small exotic mammals represent a diverse group of pets with widely varying types of care, diet, and husbandry considerations; thus, environmental enrichment must go beyond the cage or tank design in order to provide proper mental fitness in meeting any pet's psychological needs. Addressing the pet's environmental, dietary, exercise, and social needs is vital to keeping these animals healthier and more disease resistant. The key to accomplishing this is largely impacted by the annual or biannual veterinary wellness visit and a commitment from the pet's owner.

  10. Exotic magnetic states in Pauli-limited superconductors

    NASA Astrophysics Data System (ADS)

    Kenzelmann, M.

    2017-03-01

    Magnetism and superconductivity compete or interact in complex and intricate ways. Here we review the special case where novel magnetic phenomena appear due to superconductivity, but do not exist without it. Such states have recently been identified in unconventional superconductors. They are different from the mere coexistence of magnetic order and superconductivity in conventional superconductors, or from competing magnetic and superconducting phases in many materials. We describe the recent progress in the study of such exotic magnetic phases, and articulate the many open questions in this field.

  11. Principles of Wound Management and Wound Healing in Exotic Pets.

    PubMed

    Mickelson, Megan A; Mans, Christoph; Colopy, Sara A

    2016-01-01

    The care of wounds in exotic animal species can be a challenging endeavor. Special considerations must be made in regard to the animal's temperament and behavior, unique anatomy and small size, and tendency toward secondary stress-related health problems. It is important to assess the entire patient with adequate systemic evaluation and consideration of proper nutrition and husbandry, which could ultimately affect wound healing. This article summarizes the general phases of wound healing, factors that affect healing, and principles of wound management. Emphasis is placed on novel methods of treating wounds and species differences in wound management and healing.

  12. Local and exotic components of primitive meteorites, and their origin

    NASA Technical Reports Server (NTRS)

    Anders, E.

    1987-01-01

    The chemical and isotopic compositions of chondrites and their implications for chondrite origins are considered, reviewing the results of recent theoretical and experimental investigations. Numerical data are compiled in tables and graphs and discussed in detail. Consideration is given to the properties and classifications of chondrites; components of local origin in the matrix, chondrules, Ca-Al-rich inclusions, and carbon and organic matter; exotic components such as O-16-enriched dust, nucleosynthetic anomalies, and extinct radionuclides; and isotopic anomalies of volatiles such as C, N, and the noble gases. The implications of the chondrite data for the stony fraction of comet nuclei are briefly indicated.

  13. Aquatic animal nutrition for the exotic animal practitioner.

    PubMed

    Corcoran, Mike; Roberts-Sweeney, Helen

    2014-09-01

    Fish are the most popular pets in the United States based on numbers and high-quality medical care is coming to be expected by owners. Increasing numbers of veterinarians are responding to this need and providing veterinary care for aquatic animals. Part of good medical care for exotic animals is advice on husbandry, including nutrition. However, there are numerous missing areas of research for the nutritional needs of many ornamental fish species. What is known for food species can be combined with what is known for ornamental species to give nutritional advice to owners to maximize health in these animals.

  14. Overview of the status/results in the exotics sector

    NASA Astrophysics Data System (ADS)

    Shen, Chengping; Li, Changsheng

    2016-11-01

    Many exotic hadronic states beyond the conventional quark model (called char-moniumlike/bottomoniumlike states or XYZ particles) were found in the B-factories or energy scans of the cross sections of e+e- annhilation into conventional quarkonia and light hadrons. Their nature properties were proposed including glueballs, hybrids, multi-quark states, hadron molecules, etc. Dramatic progress was made in the study of the them after the running of the B-factories. In this report, I present the most recent results on the XYZ results from Belle experiment.

  15. New results on the structure of exotic nuclei

    NASA Astrophysics Data System (ADS)

    Sakurai, Hiroyoshi

    2015-04-01

    `Exotic nuclei' far from the stability line are unique objects of many-body quantum system, where ratios of neutron number to proton number are much larger or much smaller than those of nuclei found in nature. Their exotic properties and phenomena emerge from their large isospin asymmetry, and even affect scenarios of nucleosynthesis in universe. One of the exotic emergences is shell evolution. The magic numbers of stable nuclei are known; 2, 8, 20, 28, 50, 82 and 126. However the numbers 8, 20 and 28 have been found no more magic in a neutron-rich region, and new magic numbers such as 6, 16, 32 and 34 have been discovered. To access nuclei far from the stability line, especially neutron-rich nuclei, a large heavy-ion accelerator facility `Radioactive Isotope Beam Factory (RIBF)' was constructed at RIKEN, Japan in 2007. The facility is highly optimized for inflight production of fission fragments via a U beam. The accelerator complex delivers an intense 345 MeV/u U beam. The U nuclide is converted at a target to fission fragments. The fragments of interest are collected and separated at an inflight separator, and are delivered to several experimental devices. The shell evolution programs at RIBF have been conducted with two methods; in-beam gamma spectroscopy and decay spectroscopy. A standard setup of in-beam gamma spectroscopy is combination of a NaI gamma detector array `DALI2' and a beam line spectrometer `ZeroDegree Spectrometer (ZDS)'. Coincidence measurements of de-excitation gamma rays at DALI2 and of reaction products at ZDS make it possible to select reaction channels event-by-event and to observe excited states of exotic nuclei in a specific reaction channel. Recently, a French-made thick liquid hydrogen target system `MINOS' has been introduced to access more neutron-rich nuclei. Isomer and beta-delayed gamma spectroscopy is organized with a Euroball germanium cluster array system `EURICA' and an active silicon stopper In this talk, I would like to

  16. Using Superconducting Qubit Circuits to Engineer Exotic Lattice Systems

    NASA Astrophysics Data System (ADS)

    Tsomokos, Dimitris; Ashhab, Sahel; Nori, Franco

    2011-03-01

    We propose an architecture based on superconducting qubits and resonators for the implementation of a variety of exotic lattice systems, such as spin and Hubbard models in higher or fractal dimensions and higher-genus topologies. Spin systems are realized naturally using qubits, while superconducting resonators can be used for the realization of Bose-Hubbard models. Fundamental requirements for these designs, such as controllable interactions between arbitrary qubit pairs, have recently been implemented in the laboratory, rendering our proposals feasible with current technology.

  17. Using superconducting qubit circuits to engineer exotic lattice systems

    NASA Astrophysics Data System (ADS)

    Tsomokos, Dimitris I.; Ashhab, Sahel; Nori, Franco

    2010-11-01

    We propose an architecture based on superconducting qubits and resonators for the implementation of a variety of exotic lattice systems, such as spin and Hubbard models in higher or fractal dimensions and higher-genus topologies. Spin systems are realized naturally using qubits, while superconducting resonators can be used for the realization of Bose-Hubbard models. Fundamental requirements for these designs, such as controllable interactions between arbitrary qubit pairs, have recently been implemented in the laboratory, rendering our proposals feasible with current technology.

  18. Direct Reactions at Relativistic Energies: A New Insight into the Single-Particle Structure of Exotic Nuclei

    NASA Astrophysics Data System (ADS)

    Cortina-Gil, Dolores

    Direct reactions proceed in a single step, allowing to disentangle structural properties of nuclei from the reaction mechanism. The availability of radioactive beams gives rise to a renewed activity in this field enlarging the opportunities to explore the single-particle properties of exotic nuclei. Different kinds of direct reactions have been employed in different energy regimes. At high energies, the removal of one(two)-nucleon(s) (referred to as nucleon knockout in this text) from a fast exotic projectile has been extensively investigated, exploring the nuclear structure of the peripheral tail of wave functions and providing a direct insight into the single-particle properties. More than 25 years of experimental and theoretical work will be reviewed in this lecture. This exploration has recently been rejuvenated with the possibility of quasi-free scattering applied to rare isotopes. This method will be a substantial part of the program of future experimental facilities, with the results of pilot experiments now coming to light. Quasi-free scattering will complement the information gained with nucleon knockout studies, exploring deeper regions in the wave function and allowing the determination of spectral functions for both weakly and deeply bound nucleons. This lecture provides a general overview of the experimental achievements reached so far using both complementary techniques. A brief introduction to the reaction mechanisms and a simplified interpretation of the observables obtained will be presented.

  19. On wormholes with arbitrarily small quantities of exotic matter

    SciTech Connect

    Fewster, Christopher J.; Roman, Thomas A.

    2005-08-15

    Recently several models of traversable wormholes have been proposed which require only arbitrarily small amounts of negative energy to hold them open against self-collapse. If the exotic matter is assumed to be provided by quantum fields, then quantum inequalities can be used to place constraints on the negative energy densities required. In this paper, we introduce an alternative method for obtaining constraints on wormhole geometries, using a recently derived quantum inequality bound on the null-contracted stress-energy averaged over a timelike worldline. The bound allows us to perform a simplified analysis of general wormhole models, not just those with small quantities of exotic matter. We then use it to study, in particular, the models of Visser, Kar, and Dadhich (VKD) and the models of Kuhfittig. The VKD models are constrained to be either submicroscopic or to have a large discrepancy between throat size and curvature radius. A recent model of Kuhfittig is shown to be nontraversable. This is due to the fact that the throat of his wormhole flares outward so slowly that light rays and particles, starting from outside the throat, require an infinite lapse of affine parameter to reach the throat.

  20. Introduction: Exotic Annual Bromus in the Western USA

    USGS Publications Warehouse

    Germino, Matthew; Chambers, Jeanne C.; Brown, Cynthia S.

    2016-01-01

    The spread and impacts of exotic species are unambiguous, global threats to many ecosystems. A prominent example is the suite of annual grasses in the Bromus genus (Bromus hereafter) that originate from Europe and Eurasia but have invaded or are invading large areas of the Western USA. This book brings a diverse, multidisciplinary group of authors together to synthesize current knowledge, research needs, and management implications for Bromus. Exotic plant invasions are multifaceted problems, and understanding and managing them requires the biological, ecological, sociological, and economic perspectives that are integrated in this book. Knowing how well information from one geographic or environmental setting can transfer to another is a key need for broadly distributed Bromus species especially given ongoing climate change. Thus, the chapters in the book compare and contrast invasibility of different ecoregions and invasiveness of different Bromus species. A universal theme is managing for ecosystems that are resilient to disturbance and resistant to invasion which will be essential for adaptation to the human-caused problem of Bromus in the Western USA.

  1. Exotic invaders gain foraging benefits by shoaling with native fish

    PubMed Central

    Camacho-Cervantes, Morelia; Garcia, Constantino Macías; Ojanguren, Alfredo F.; Magurran, Anne E.

    2014-01-01

    Freshwater habitats are under increasing threat due to invasions of exotic fish. These invasions typically begin with the introduction of small numbers of individuals unfamiliar with the new habitat. One way in which the invaders might overcome this disadvantage is by associating with native taxa occupying a similar ecological niche. Here we used guppies (Poecilia reticulata) from a feral population in Mexico to test the prediction that exotic shoaling fish can associate with heterospecifics, and that they improve their foraging efficiency by doing so. Guppies have invaded the Mexican High Plateau and are implicated in the declines of many native topminnow (Goodeinae) species. We show that heterospecific associations between guppies and topminnows can deliver the same foraging benefits as conspecific shoals, and that variation in foraging gains is linked to differences in association tendency. These results uncover a mechanism enabling founding individuals to survive during the most vulnerable phase of an invasion and help explain why guppies have established viable populations in many parts of Mexico as well in every continent except Antarctica. PMID:26064552

  2. PREFACE: International Nuclear Physics Conference 2010 (INPC2010)

    NASA Astrophysics Data System (ADS)

    Dilling, Jens

    2011-09-01

    Hot and Dense QCD reporting on experimental and theoretical progress at the RHIC facility. The Nuclear Reactions session provided highlights from the many new and exciting facilities including the RIKEN RIBF in Japan, and an outlook of what we can expect from FAIR (Germany) and FRIB (USA). The quest towards the 'Island of Stability' for the Superheavy Element community is still on, and new progress was reported with the identification of element 114. Impressive progress in the theoretical sector, in particular with ab-initio approaches, was presented as well. Applications of these methods and progress in the nucleon-nucleon interactions were presented in the Nuclear Structure session, where 3-body forces interactions are now considered state of the art. Predictions of such calculations can then be tested by experiments, as presented, for example, for ground state properties of exotic nuclei with laser experiments and ion trap measurements. In-beam or in-flight experiments pave the way to even more exotic isotopes where new magic numbers for the nuclear shell model are appearing. This will also prove relevant for Nuclear Astrophysics, where significant progress was achieved experimentally with new direct capture reaction measurements with rare beams and background suppressed facilities located in underground laboratories. Neutron star research and new modeling results of core-collapse supernovae were presented, which clearly indicated the need for neutrino interactions. Neutrinos also played a large role in other sessions such as the New Facilities and Instrumentation session where, among other new exciting projects, the deep underground facilities were presented. The first beam results from long-baseline oscillation experiments showed progress in this field, and double-beta decay experiments are nearing their first possible results, something that the community of nuclear physicists, but also others, are keenly waiting for. The Standard Model Tests and Fundamental

  3. Novel fibre-optic-based ionization radiation probes

    NASA Astrophysics Data System (ADS)

    Jackson, David A.

    2004-06-01

    CsI ionization radiation probes interrogated via a fiber optic transceiver link for monitoring medical procedures such as Intensity Modulated Radiotherapy, Brachytherapy and Nuclear Medicine are presented together with potential industrial, environmental and military applications.

  4. Predicting invasion in grassland ecosystems: Is exotic dominance the real embarrassment of richness?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For two centuries there has been a perception that while exotic species are dominant in many areas, others remain largely unaffected. This unquantified observation suggests a fundamental ecological question: why do exotics dominate some locations and not others? While invasions are clearly important...

  5. A new perspective on trait differences between native and invasive exotic plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Functional differences between native and exotic species are often presumed to be one factor responsible for plant invasion. Accordingly, invasion occurs when a niche is vacated and an exotic species enters the community that is able to exploit available resources. Differences in trait values betw...

  6. Exotic diseases of dogs and cats at risk of importation to Ireland

    PubMed Central

    2005-01-01

    Changes in legislation that facilitate movement of companion animals within the European Union will expose those animals to microbial and parasitic organisms currently exotic to Ireland. This paper reviewed information on the exotic diseases most likely to be introduced to Ireland by travelling dogs and cats: rabies, leishmaniosis, babesiosis, ehrlichiosis, anaplasmosis and dirofilariosis. PMID:21851670

  7. Overview of veterinary chiropractic and its use in pediatric exotic patients.

    PubMed

    Maler, Marilyn M

    2012-05-01

    The scope of this article will be an introduction to veterinary chiropractic and its use in treating pediatric exotic patients. After discussing the general principles of human and veterinary chiropractic, the special considerations of adjusting exotic pediatric patients will be explored.

  8. Exotic plant traits lead to functional diversity decline in novel ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exotic species have become common and even dominant in some grasslands forming novel ecosystems because the species in them have no common evolutionary history. Recent work on these novel ecosystems suggest that exotic species contribute to diversity declines. In order to identify the plant traits...

  9. 75 FR 52967 - Final Environmental Impact Statement and South Florida and Caribbean Parks Exotic Plant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... Palm Beach, Florida. A Notice of Intent to prepare an environmental impact statement (EIS) for South... National Park Service Final Environmental Impact Statement and South Florida and Caribbean Parks Exotic... environmental impact statement for the South Florida and Caribbean Parks Exotic Plant Management Plan....

  10. Weak gravity conjecture as a razor criterium for exotic D-brane instantons

    NASA Astrophysics Data System (ADS)

    Addazi, Andrea

    2017-01-01

    We discuss implications of weak gravity conjecture (WGC) for exotic D-brane instantons. In particular, WGC leads to indirect stringent bounds on non-perturbative superpotentials generated by exotic instantons with many implications for phenomenology: R-parity violating processes, neutrino mass, μ-problem, neutron-antineutron transitions and collider physics.

  11. Use of exotic plants to control Spartina alterniflora invasion and promote mangrove restoration

    PubMed Central

    Zhou, Ting; Liu, Shuchao; Feng, Zhili; Liu, Gang; Gan, Qian; Peng, Shaolin

    2015-01-01

    In coastal China, the exotic invasive Spartina alterniflora is preventing the establishment of native mangroves. The use of exotic species, control of exotic plant invasion, and restoration of native plant communities are timely research issues. We used exotic Sonneratia apetala Buch.-Ham and S. caseolaris (L.) Engl. to control invasive Spartina alterniflora Loisel through replacement control for five years, which concurrently promoted the restoration of native mangroves. This process includes three stages. I: In a mangrove area invaded by S. alterniflora, exotic S. apetala and S. caseolaris grew rapidly due to their relatively fast-growing character and an allelopathic effect. II: Fast-growing S. apetala and S. caseolaris eradicate S. alterniflora through shading and allelopathy. III: The growth of native mangrove was promoted because exotic plant seedlings cannot regenerate in the understory shade, whereas native mesophytic mangrove plants seedlings can grow; when the area experiences extreme low temperatures in winter or at other times, S. apetala dies, and native mangrove species grow to restore the communities. This model has important implications for addressing the worldwide problems of “how to implement the ecological control of invasion using exotic species” and “how to concurrently promote native community restoration during the control of exotic invasion”. PMID:26291074

  12. 9 CFR 352.3 - Application by official exotic animal establishment for inspection services.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Application by official exotic animal establishment for inspection services. 352.3 Section 352.3 Animals and Animal Products FOOD SAFETY...

  13. 9 CFR 352.3 - Application by official exotic animal establishment for inspection services.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Application by official exotic animal establishment for inspection services. 352.3 Section 352.3 Animals and Animal Products FOOD SAFETY...

  14. 9 CFR 352.3 - Application by official exotic animal establishment for inspection services.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Application by official exotic animal establishment for inspection services. 352.3 Section 352.3 Animals and Animal Products FOOD SAFETY...

  15. 9 CFR 352.3 - Application by official exotic animal establishment for inspection services.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Application by official exotic animal establishment for inspection services. 352.3 Section 352.3 Animals and Animal Products FOOD SAFETY...

  16. 9 CFR 352.3 - Application by official exotic animal establishment for inspection services.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Application by official exotic animal establishment for inspection services. 352.3 Section 352.3 Animals and Animal Products FOOD SAFETY...

  17. Plant community diversity and native plant abundance decline with increasing abundance of an exotic annual grass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exotic plants are generally considered a serious problem in wildlands around the globe. However, some argue that the impacts of exotic plants have been exaggerated and that biodiversity and other important plant community characteristics are commonly improved with invasion. Thus, disagreement exis...

  18. Spontaneous hybrids between native and exotic Rubus in the Western United States produce offspring both by apomixis and by sexual recombination.

    PubMed

    Clark, L V; Jasieniuk, M

    2012-11-01

    Facultative asexual reproduction is a trait commonly found in invasive species. With a combination of sexual and asexual reproductive modes, such species may adapt to new environments via sexual recombination during range expansion, while at the same time having the benefits of asexuality such as the maintenance of fitness effects that depend upon heterozygosity. In the Western United States, native species of Rubus (Rosaceae) reproduce sexually whereas exotic naturalized Rubus species reproduce by pseudogamous apomixis. We hypothesized that new asexual lineages of Rubus could arise from hybridization in this range. To detect hybridization between native and exotic Rubus, we genotyped 579 individuals collected across California, Oregon and Washington with eight nuclear microsatellites and two chloroplast markers. Principal Coordinate Analysis and Bayesian clustering revealed a limited amount of hybridization of the native R. ursinus with the exotic R. armeniacus and R. pensilvanicus, as well as cultivated varieties. Genetic distances between these hybrids and their offspring indicated that both R. ursinus × R. armeniacus and R. ursinus × R. pensilvanicus produced a mix of apomictic and sexual seeds, with sexual seeds being more viable. Although neither of these hybrid types is currently considered invasive, they model the early stages of evolution of new invasive lineages, given the potential for fixed heterosis and the generation of novel genotypes. The hybrids also retain the ability to increase their fitness via sexual recombination and natural selection. Mixed reproductive systems such as those described here may be an important step in the evolution of asexual invasive species.

  19. Nuclear rights - nuclear wrongs

    SciTech Connect

    Paul, E.F.; Miller, F.D.; Paul, J.; Ahrens, J.

    1986-01-01

    This book contains 11 selections. The titles are: Three Ways to Kill Innocent Bystanders: Some Conundrums Concerning the Morality of War; The International Defense of Liberty; Two Concepts of Deterrence; Nuclear Deterrence and Arms Control; Ethical Issues for the 1980s; The Moral Status of Nuclear Deterrent Threats; Optimal Deterrence; Morality and Paradoxical Deterrence; Immoral Risks: A Deontological Critique of Nuclear Deterrence; No War Without Dictatorship, No Peace Without Democracy: Foreign Policy as Domestic Politics; Marxism-Leninism and its Strategic Implications for the United States; Tocqueveille War.

  20. Comparison of endemic and exotic entomopathogenic nematode species for control of Colorado potato beetle (Coleoptera: Chrysomelidae).

    PubMed

    Berry, R E; Liu, J; Reed, G

    1997-12-01

    We compared the efficacy of 2 endemic strains of entomopathogenic nematodes isolated from Hermiston, OR, with that of 3 exotic nematode species for control of Colorado potato beetle, Leptinotarsa decemlineata (Say). In laboratory experiments, the exotic Heterorhabditis species were more pathogenic to Colorado potato beetle than were the endemic Heterorhabditis strains. Exotic Steinernema species were less pathogenic to Colorado potato beetle than the exotic Heterorhabditis species. No Colorado potato beetle adults emerged from soil treated with H. marelatus Liu & Berry, a new species collected from Seaside, OR. Nematode pathogenicity was detected up to 14 wk after application in Galleria mellonella (L.) in soil taken from field plots treated with endemic and exotic nematode species.

  1. The TRIple PLunger for EXotic beams TRIPLEX for excited-state lifetime measurement studies on rare isotopes

    NASA Astrophysics Data System (ADS)

    Iwasaki, H.; Dewald, A.; Braunroth, T.; Fransen, C.; Smalley, D.; Lemasson, A.; Morse, C.; Whitmore, K.; Loelius, C.

    2016-01-01

    A new device, the TRIple PLunger for EXotic beams (TRIPLEX), has been developed for lifetime measurement studies with rare isotope beams. This plunger device holds up to three metal foils in the beam path and facilitates the recoil distance Doppler-shift technique to measure lifetimes of nuclear excited states in the range of 1 ps to 1 ns. The unique design allows independent movement of the target and the second degrader with respect to a fixed first degrader in between, enabling advanced experimental approaches, such as the differential recoil distance method and the double recoil distance method. The design and control of the device are presented in this paper, together with simulated performances of the new applications. As an example of actual experiments, results from the lifetime measurement of the neutron-rich 17C isotope performed at the National Superconducting Cyclotron Laboratory are shown.

  2. Hydrodynamic ultrasonic probe

    DOEpatents

    Day, Robert A.; Conti, Armond E.

    1980-01-01

    An improved probe for in-service ultrasonic inspection of long lengths of a workpiece, such as small diameter tubing from the interior. The improved probe utilizes a conventional transducer or transducers configured to inspect the tubing for flaws and/or wall thickness variations. The probe utilizes a hydraulic technique, in place of the conventional mechanical guides or bushings, which allows the probe to move rectilinearly or rotationally while preventing cocking thereof in the tube and provides damping vibration of the probe. The probe thus has lower friction and higher inspection speed than presently known probes.

  3. Probe tip heating assembly

    SciTech Connect

    Schmitz, Roger William; Oh, Yunje

    2016-10-25

    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably received and clamped within the socket.

  4. Increasing native, but not exotic, biodiversity increases aboveground productivity in ungrazed and intensely grazed grasslands.

    PubMed

    Isbell, Forest I; Wilsey, Brian J

    2011-03-01

    Species-rich native grasslands are frequently converted to species-poor exotic grasslands or pastures; however, the consequences of these changes for ecosystem functioning remain unclear. Cattle grazing (ungrazed or intensely grazed once), plant species origin (native or exotic), and species richness (4-species mixture or monoculture) treatments were fully crossed and randomly assigned to plots of grassland plants. We tested whether (1) native and exotic plots exhibited different responses to grazing for six ecosystem functions (i.e., aboveground productivity, light interception, fine root biomass, tracer nitrogen uptake, biomass consumption, and aboveground biomass recovery), and (2) biodiversity-ecosystem functioning relationships depended on grazing or species origin. We found that native and exotic species exhibited different responses to grazing for three of the ecosystem functions we considered. Intense grazing decreased fine root biomass by 53% in exotic plots, but had no effect on fine root biomass in native plots. The proportion of standing biomass consumed by cattle was 16% less in exotic than in native grazed plots. Aboveground biomass recovery was 30% less in native than in exotic plots. Intense grazing decreased aboveground productivity by 25%, light interception by 14%, and tracer nitrogen uptake by 54%, and these effects were similar in native and exotic plots. Increasing species richness from one to four species increased aboveground productivity by 42%, and light interception by 44%, in both ungrazed and intensely grazed native plots. In contrast, increasing species richness did not influence biomass production or resource uptake in ungrazed or intensely grazed exotic plots. These results suggest that converting native grasslands to exotic grasslands or pastures changes ecosystem structure and processes, and the relationship between biodiversity and ecosystem functioning.

  5. Space Exploration; Power Sources for Deep Space Probes

    DTIC Science & Technology

    1998-05-01

    are Europa Orbiter, Pluto Express, Solar Probe, Interstellar Probe, Europa Lander, Io Volcanic Observer, Titan Organic Explorer, and Neptune Orbiter...example, the new nuclear-fueled generator that NASA studied for use on the Pluto Express spacecraft is projected to need less than 10 pounds of

  6. The exotic conformal Galilei algebra and nonlinear partial differential equations

    NASA Astrophysics Data System (ADS)

    Cherniha, Roman; Henkel, Malte

    2010-09-01

    The conformal Galilei algebra (CGA) and the exotic conformal Galilei algebra (ECGA) are applied to construct partial differential equations (PDEs) and systems of PDEs, which admit these algebras. We show that there are no single second-order PDEs invariant under the CGA but systems of PDEs can admit this algebra. Moreover, a wide class of nonlinear PDEs exists, which are conditionally invariant under CGA. It is further shown that there are systems of non-linear PDEs admitting ECGA with the realisation obtained very recently in [D. Martelli and Y. Tachikawa, arXiv:0903.5184v2 [hep-th] (2009)]. Moreover, wide classes of non-linear systems, invariant under two different 10-dimensional subalgebras of ECGA are explicitly constructed and an example with possible physical interpretation is presented.

  7. Self-isospectrality, mirror symmetry, and exotic nonlinear supersymmetry

    SciTech Connect

    Plyushchay, Mikhail S.; Nieto, Luis-Miguel

    2010-09-15

    We study supersymmetry of a self-isospectral one-gap Poeschl-Teller system in the light of a mirror symmetry that is based on spatial and shift reflections. The revealed exotic, partially broken, nonlinear supersymmetry admits seven alternatives for a grading operator. One of its local, first order supercharges may be identified as a Hamiltonian of an associated one-gap, nonperiodic Bogoliubov-de Gennes system. The latter possesses a nonlinear supersymmetric structure, in which any of the three nonlocal generators of a Clifford algebra may be chosen as the grading operator. We find that the supersymmetry generators for both systems are the Darboux-dressed integrals of a free spin-1/2 particle in the Schroedinger picture, or of a free massive Dirac particle. Nonlocal Foldy-Wouthuysen transformations are shown to be involved in the supersymmetric structure.

  8. Human behavioral regularity, fractional Brownian motion, and exotic phase transition

    NASA Astrophysics Data System (ADS)

    Li, Xiaohui; Yang, Guang; An, Kenan; Huang, Jiping

    2016-08-01

    The mix of competition and cooperation (C&C) is ubiquitous in human society, which, however, remains poorly explored due to the lack of a fundamental method. Here, by developing a Janus game for treating C&C between two sides (suppliers and consumers), we show, for the first time, experimental and simulation evidences for human behavioral regularity. This property is proved to be characterized by fractional Brownian motion associated with an exotic transition between periodic and nonperiodic phases. Furthermore, the periodic phase echoes with business cycles, which are well-known in reality but still far from being well understood. Our results imply that the Janus game could be a fundamental method for studying C&C among humans in society, and it provides guidance for predicting human behavioral activity from the perspective of fractional Brownian motion.

  9. Clinical trials with canine distemper vaccines in exotic carnivores.

    PubMed

    Montali, R J; Bartz, C R; Teare, J A; Allen, J T; Appel, M J; Bush, M

    1983-12-01

    Two types of killed canine distemper virus (CDV) vaccine and a modified-live CDV vaccine were clinically evaluated in four species of exotic carnivores. In 16 trials in which 13 red pandas (Ailurus fulgens) were given the killed vaccine, only 1 animal had a virus-neutralization titer that exceeded 1:100. A red panda given modified-live CDV vaccine deemed safe for gray foxes and ferrets died of bacterial pneumonia 16 days later. There was no pathologic evidence of canine distemper in that panda. The same modified-live vaccine proved to be immunogenic and safe in 12 bush dogs (Speothos venaticus), 5 maned wolves (Chrysocyon brachyurus), and 3 fennec foxes (Fennecus zerda) in which virus-neutralization titers often exceeded 1:512 and persisted for several months after vaccination.

  10. Apollo 15 yellow impact glasses: Chemistry, petrology, and exotic origin

    SciTech Connect

    Delano, J.W.; Lindsley, D.H.; Ma, M.; Schmitt, R.A.

    1982-11-15

    The Apollo 15 yellow impact glasses are characterized by moderate TiO/sub 2/ (approx.4.8%) and high abundances of the large ion lithophile elements (e.g., K, P, Hf, Th, REE). Since the chemistry of these glasses cannot be duplicated by any combination of local components presently known to occur at the Apollo 15 landing site, these yellow glasses seem to be exotic to that area. Chemical and petrologic constraints suggest that these samples were produced by impact melting of an immature mare regolith developed upon an unusual variety of mare basalt. We speculate that the target basalt were the youngest lava flows known to exist on the moon (i.e., Eratosphenian-age lavas in Oceanus Procellarum and Mare Imbrium). Specific tests are proposed for evaluating this provocative hypothesis.

  11. Resonance X(5568) as an exotic axial-vector state

    NASA Astrophysics Data System (ADS)

    Agaev, S. S.; Azizi, K.; Barsbay, B.; Sundu, H.

    2017-01-01

    The mass and meson-current coupling constant of the resonance X(5568), as well as the width of the decay X(5568)→ Bs^{ast}π are calculated by modeling the exotic X(5568) resonance as a diquark-antidiquark state Xb=[su][bd] with quantum numbers JP=1+. The calculations are made employing QCD two-point sum rule method, where the quark, gluon and mixed vacuum condensates up to dimension eight are taken into account. The sum rule approach on the light-cone in its soft-meson approximation is used to explore the vertex XbBs^{ast}π and extract the strong coupling g_{XbBs^{ast}π}, which is a necessary ingredient to find the width of the Xb→ Bs^{ast}π+ decay process. The obtained predictions are compared with the experimental data of the D0 Collaboration, and results of other theoretical works.

  12. X-ray emission of exotic ions in dense plasmas

    NASA Astrophysics Data System (ADS)

    Rosmej, F. B.; Khaghani, D.; Dozières, M.; Dachicourt, R.; Šmíd, M.; Renner, O.

    2017-03-01

    Hollow ion X-ray emission has been observed in experiments studying interaction of heavy ion beams with solids and their occurrence has been ascribed to charge exchange processes occurring when highly charged ions interact with a metal surface. In high temperature high-density plasmas, like, e.g., high intensity laser produced plasmas or high current Z-pinches, numerous researchers have reported about "exotic" X-ray transitions of hollow ions: K0LX →K1LX-1+hνhollow. Although atomic structure calculations seem to confirm that measured line positions correspond to transitions in hollow ions, line identification is difficult and the observed high intensity remains a mystery (by orders of magnitude) up to present days.

  13. Indicators of exotic biology in the K/T transition

    NASA Astrophysics Data System (ADS)

    Wallis, K.; Ramadurai, S.

    1 than particular fungi and gave rise to competitive evolution of the ordinary and alien organisms until resistant species (including mammals) won through or symbiotic relationships with the fungal invaders developed. Why would the invaders have come from the inner Oort cloud just beyond Uranus? The probability of the solar system catching an interstellar comet is low. But also their exotic biology was not highly different, as AIB forms an alpha-helix and peptaibols comprise mainly ordinary (protein) aminoacids. Judging by locational variations in AIB abundance, the invaders were not globally overwhelmingly successful and may have depended on repeated reinvasions over at least 100,000 years. Why do virulent invaders arrive every million years with each fragmenting giant comet? Maybe interplanetary debris prevents the isolation of EK-Comets so that biologies rarely evolve sufficiently divergent over the billion years time-scale.

  14. Prospects for exotics and LFV at NA62

    NASA Astrophysics Data System (ADS)

    Petrov, P.

    2017-01-01

    The NA62 experiment at the CERN SPS is designed to measure the branching ratio of the ultra-rare decay with 10% precision. For this purpose the experiment aims to collect of the order of 100 events which would require at least 1013 K + decays in the fiducial volume of the detector. The large sample of K+ decays that will be available at NA62 allows the experiment to carry out a rich program for rare and forbidden K+ and π 0 decays, including lepton flavour and/or number violating modes, sterile neutrinos, exotic particles (e.g. Dark Photons). NA62’s potential for such searches in K+ and π 0 decays is discussed, with initial sensitivity estimates. In addition, plans for continuing the experiment after 2021 (Long Shutdown 2) are presented, including in particular the possibility to operate in a beam-dump mode for exploring various Dark Matter scenarios.

  15. Towards Exotic Hidden-Charm Pentaquarks in QCD.

    PubMed

    Chen, Hua-Xing; Chen, Wei; Liu, Xiang; Steele, T G; Zhu, Shi-Lin

    2015-10-23

    Inspired by P(c)(4380) and P(c)(4450) recently observed by LHCb, a QCD sum rule investigation is performed, by which they can be identified as exotic hidden-charm pentaquarks composed of an anticharmed meson and a charmed baryon. Our results suggest that P(c)(4380) and P(c)(4450) have quantum numbers J(P)=3/2(-) and 5/2(+), respectively. Furthermore, two extra hidden-charm pentaqurks with configurations D̅Σ(c)(*) and D̅(*)Σ(c)(*) are predicted, which have spin-parity quantum numbers J(P)=3/2(-) and J(P)=5/2(+), respectively. As an important extension, the mass predictions of hidden-bottom pentaquarks are also given. Searches for these partners of P(c)(4380) and P(c)(4450) are especially accessible at future experiments like LHCb and BelleII.

  16. Exotic encounters with dental implants: managing complications with unidentified systems.

    PubMed

    Mattheos, N; Janda, M Schittek

    2012-06-01

    As the application of dental implants increases worldwide, so is the number of technical and biological complications that general dental practitioners will be called to manage, while maintaining implant patients. In addition, the greater patient mobility encountered today combined with a growing trend of 'dental implant tourism' will very often result in situations where the dentist is requested to deal with complications in implants placed elsewhere and which sometimes might be of an 'exotic' system one cannot directly recognize. Such a situation can pose significant challenges to even experienced clinicians. The challenges are not only in the scientific field, but often include professional and ethical implications. This case report will discuss strategies for the management of implant complications in cases of unidentified implant systems. Critical factors in such situations would be the clinician's experience and special training, the correct radiographic technique, as well as access to the appropriate tools and devices.

  17. Exotic α decays around the N=126 magic shell

    NASA Astrophysics Data System (ADS)

    Ni, Dongdong; Ren, Zhongzhou

    2009-07-01

    We investigate the α-decay half-lives of the exotic N=125,126,127 isotones by the generalized density-dependent cluster model (GDDCM) in combination with the microscopic two-level model. The decay widths are calculated using the overlap integral of the quasibound state wave function, the scattering state wave function, and the difference of potentials, instead of using the simple semiclassical WKB method along with the Bohr-Sommerfeld quantization condition. The α-preformation factors are evaluated by the Z-dependent formula based on the two-level model, where the closed-shell effect is included. The calculated half-lives of α transitions to both ground states and excited states are found to be in good agreement with the experimental data.

  18. How to reveal the exotic nature of the Pc(4450 )

    NASA Astrophysics Data System (ADS)

    Guo, Feng-Kun; Meißner, Ulf-G.; Wang, Wei; Yang, Zhi

    2015-10-01

    The LHCb Collaboration announced two pentaquark-like structures in the J /ψ p invariant mass distribution. We show that the current information on the narrow structure at 4.45 GeV is compatible with kinematical effects of the rescattering from χc 1p to J /ψ p : First, it is located exactly at the χc 1p threshold. Second, the mass of the four-star well-established Λ (1890 ) is such that a leading Landau singularity from a triangle diagram can coincidentally appear at the χc 1p threshold, and third, there is a narrow structure at the χc 1p threshold but not at the χc 0p and χc 2p thresholds. In order to check whether that structure corresponds to a real exotic resonance, one can measure the process Λb0→K-χc 1p . If the Pc(4450 ) structure exists in the χc 1p invariant mass distribution as well, then the structure cannot be just a kinematical effect but is a real resonance; otherwise, one cannot conclude that Pc(4450 ) is another exotic hadron. In addition, it is also worthwhile to measure the decay ϒ (1 S )→J /ψ p p ¯ : a narrow structure at 4.45 GeV but not at the χc 0p and χc 2p thresholds would exclude the possibility of a pure kinematical effect.

  19. Ground state proton radioactivity from 121Pr: when was this exotic nuclear decay mode first discovered?

    PubMed

    Robinson, A P; Woods, P J; Seweryniak, D; Davids, C N; Carpenter, M P; Hecht, A A; Peterson, D; Sinha, S; Walters, W B; Zhu, S

    2005-07-15

    Ground-state proton radioactivity has been identified from 121Pr. A transition with a proton energy of E(p)=882(10) keV [Q(p)=900(10) keV] and half-life t(1/2)=10(+6)(-3) ms has been observed and is assigned to the decay of a highly prolate deformed 3/2(+) or 3/2(-) Nilsson state. The present result is found to be incompatible with a previously reported observation of ground-state proton radioactivity from 121Pr, which would have represented the discovery of this phenomenon.

  20. Nuclear pulse. III - Playing a wild card

    NASA Astrophysics Data System (ADS)

    Broad, W. J.

    1981-06-01

    Implications of the phenomenon of electromagnetic pulse (EMP), a high-voltage by-product of nuclear explosions in space which could render useless unprotected communications equipment and power grids over a wide area, for the feasibility of conducting a limited nuclear war by the United States are discussed. Arguments on the one hand that the effects of EMP demand direct investigation and should be protected against by the hardening of U.S. military communications are summarized and contrasted with those on the other hand which assert that the presence of EMP, as well as other exotic nuclear effects, would, despite any attempts at hardening, make it impossible to maintain the precision of command and control necessary for a limited nuclear action against Soviet military targets. Uncertainties about Soviet intentions in regard to the use of EMP as a weapon are also pointed out.

  1. Self Assembly and Elasticity of Nuclear Pasta

    NASA Astrophysics Data System (ADS)

    Caplan, Matthew; Horowitz, Chuck; Berry, Don; da Silva Schneider, Andre

    2015-10-01

    While the outer crust of a neutron star is likely a solid ion lattice, the core consists of uniform nuclear matter at or above saturation density. In between, nuclei adopt exotic non-spherical geometries called ``nuclear pasta'' in order to minimize the nuclear attraction and Coulomb repulsion between protons. These structures have been well studied with both classical and quantum molecular dynamics, and their geometry can be predicted from the density, temperature, and proton fraction. Recent classical molecular dynamics simulations find evidence for a phase transition at T ~ 0 . 5 MeV, where simulations with low proton fractions undergo a solid-liquid phase transition, while simulations with high proton fractions under a glass-rubber phase transition. This is expected to have nontrivial consequences for the elastic properties of the pasta. Additionally, recent observations indicate that the structure of nuclear pasta may be related to structures observed in biophysics, specifically self assembling lipid membranes.

  2. Large Scale Quantum Simulations of Nuclear Pasta

    NASA Astrophysics Data System (ADS)

    Fattoyev, Farrukh J.; Horowitz, Charles J.; Schuetrumpf, Bastian

    2016-03-01

    Complex and exotic nuclear geometries collectively referred to as ``nuclear pasta'' are expected to naturally exist in the crust of neutron stars and in supernovae matter. Using a set of self-consistent microscopic nuclear energy density functionals we present the first results of large scale quantum simulations of pasta phases at baryon densities 0 . 03 < ρ < 0 . 10 fm-3, proton fractions 0 . 05 nuclear symmetry energy on these pasta configurations. This work is supported in part by DOE Grants DE-FG02-87ER40365 (Indiana University) and DE-SC0008808 (NUCLEI SciDAC Collaboration).

  3. Probing neutrino nature at Borexino detector with chromium neutrino source

    NASA Astrophysics Data System (ADS)

    Sobków, W.; Błaut, A.

    2016-10-01

    In this paper, we indicate a possibility of utilizing the intense chromium source (˜ 370 PBq) in probing the neutrino nature in low energy neutrino experiments with the ultra-low threshold and background real-time Borexino detector located near the source (˜ 8 m). We analyse the elastic scattering of electron neutrinos (Dirac or Majorana, respectively) on the unpolarised electrons in the relativistic neutrino limit. We assume that the incoming neutrino beam is the superposition of left-right chiral states produced by the chromium source. Left chiral neutrinos may be detected by the standard V - A and non-standard scalar S_L, pseudoscalar P_L, tensor T_L interactions, while right chiral ones partake only in the exotic V + A and S_R, P_R, T_R interactions. Our model-independent study is carried out for the flavour (current) neutrino eigenstates. We compute the expected event number for the standard V-A interaction of the left chiral neutrinos using the current experimental values of standard couplings and in the case of left-right chiral superposition. We show that the significant decrement in the event number due to the interference terms between the standard and exotic interactions for the Majorana neutrinos may appear. We also demonstrate how the presence of the exotic couplings affects the energy spectrum of outgoing electrons, both for the Dirac and Majorana cases. The 90~% C.L. sensitivity contours in the planes of corresponding exotic couplings are found. The presence of interferences in the Majorana case gives the stronger constraints than for the Dirac neutrinos, even if the neutrino source is placed outside the detector.

  4. Cross-Attraction between an Exotic and a Native Pine Bark Beetle: A Novel Invasion Mechanism?

    PubMed Central

    Lu, Min; Miller, Daniel R.; Sun, Jiang-Hua

    2007-01-01

    Background Aside from the ecological impacts, invasive species fascinate ecologists because of the unique opportunities that invasives offer in the study of community ecology. Some hypotheses have been proposed to illustrate the mechanisms that allow exotics to become invasive. However, positive interactions between exotic and native insects are rarely utilized to explain invasiveness of pests. Methodology/Principal Findings Here, we present information on a recently formed association between a native and an exotic bark beetle on their shared host, Pinus tabuliformis, in China. In field examinations, we found that 35–40% of P. tabuliformis attacked by an exotic bark beetle, Dendroctonus valens, were also attacked by a native pine bark beetle, Hylastes parallelus. In the laboratory, we found that the antennal and walking responses of H. parallelus to host- and beetle-produced compounds were similar to those of the exotic D. valens in China. In addition, D. valens was attracted to volatiles produced by the native H. parallelus. Conclusions/Significance We report, for the first time, facilitation between an exotic and a native bark beetle seems to involve overlap in the use of host attractants and pheromones, which is cross-attraction. The concept of this interspecific facilitation could be explored as a novel invasive mechanism which helps explain invasiveness of not only exotic bark beetles but also other introduced pests in principle. The results reported here also have particularly important implications for risk assessments and management strategies for invasive species. PMID:18074026

  5. Invasion in a diversity hotspot: Exotic cover and native richness in the Californian serpentine flora

    USGS Publications Warehouse

    Harrison, S.; Grace, J.B.; Davies, K.F.; Safford, H.D.; Viers, J.H.

    2006-01-01

    Exotic species have been observed to be more prevalent in sites where the richness of native species is highest, possibly reflecting variation among sites in resources, propagule supply, heterogeneity, or disturbance. However, such a pattern leaves unclear whether natives at species-rich sites are subject to especially severe impacts from exotics as a result. We considered this question using path models in which relationships between exotic cover and native richness were evaluated in the presence of correlated environmental factors. At 109 sites on serpentine soils across California, USA, exotic cover was positively correlated with total native herbaceous richness and was negatively correlated with the richness of both serpentine-endemic and rare native herbs. However, in path models that accounted for the influences of soil chemistry, disturbance, overstory cover, and regional rainfall and elevation, we found no indication that exotic cover reduced any component of native herb richness. Rather, our results indicated similarities and differences in the conditions favoring exotic, native, endemic, and rare species. Our results suggest that, in spite of some localized impacts, exotic species are not exerting a detectable overall effect on the community richness of the unique native flora of Californian serpentine. ?? 2006 by the Ecological Society of America.

  6. A new perspective on trait differences between native and invasive exotic plants.

    PubMed

    Leffler, A Joshua; James, Jeremy J; Monaco, Thomas A; Sheley, Roger L

    2014-02-01

    Functional differences between native and exotic species potentially constitute one factor responsible for plant invasion. Differences in trait values between native and exotic invasive species, however, should not be considered fixed and may depend on the context of the comparison. Furthermore, the magnitude of difference between native and exotic species necessary to trigger invasion is unknown. We propose a criterion that differences in trait values between a native and exotic invasive species must be greater than differences between co-occurring natives for this difference to be ecologically meaningful and a contributing factor to plant invasion. We used a meta-analysis to quantify the difference between native and exotic invasive species for various traits examined in previous studies and compared this value to differences among native species reported in the same studies. The effect size between native and exotic invasive species was similar to the effect size between co-occurring natives except for studies conducted in the field; in most instances, our criterion was not met although overall differences between native and exotic invasive species were slightly larger than differences between natives. Consequently, trait differences may be important in certain contexts, but other mechanisms of invasion are likely more important in most cases. We suggest that using trait values as predictors of invasion will be challenging.

  7. Including the introduction of exotic species in life cycle impact assessment: the case of inland shipping.

    PubMed

    Hanafiah, Marlia M; Leuven, Rob S E W; Sommerwerk, Nike; Tockner, Klement; Huijbregts, Mark A J

    2013-12-17

    While the ecological impact of anthropogenically introduced exotic species is considered a major threat for biodiversity and ecosystems functioning, it is generally not accounted for in the environmental life cycle assessment (LCA) of products. In this article, we propose a framework that includes exotic species introduction in an LCA context. We derived characterization factors for exotic fish species introduction related to the transport of goods across the Rhine-Main-Danube canal. These characterization factors are expressed as the potentially disappeared fraction (PDF) of native freshwater fish species in the rivers Rhine and Danube integrated over space and time per amount of goods transported (PDF·m(3)·yr·kg(-1)). Furthermore, we quantified the relative importance of exotic fish species introduction compared to other anthropogenic stressors in the freshwater environment (i.e., eutrophication, ecotoxicity, greenhouse gases, and water consumption) for transport of goods through the Rhine-Main-Danube waterway. We found that the introduction of exotic fish species contributed to 70-85% of the total freshwater ecosystem impact, depending on the distance that goods were transported. Our analysis showed that it is relevant and feasible to include the introduction of exotic species in an LCA framework. The proposed framework can be further extended by including the impacts of other exotic species groups, types of water bodies and pathways for introduction.

  8. Exotic Dance in Baltimore: From Entry to STI/HIV Risk

    PubMed Central

    Reuben, Jacqueline; Sherman, Susan G.

    2015-01-01

    Research has documented health risks associated with sex work, but few U.S. studies have focused on the exotic dance industry. We undertook to describe the factors that influenced women's entry into exotic dance and explored the relation of these forces to their subsequent Sexually Transmitted Infection (STI)/HIV risk trajectory. Qualitative interviews (N=25) were conducted with female exotic dancers from June through August, 2009. Data were analyzed through Atlas-ti using an inductive approach. Economic vulnerability was the primary force behind women's initiation into the profession. Drug use, physical abuse, and enjoyment of dancing were often concurrent with economic need and provided a further push toward exotic dance. Social networks facilitated entry by normalizing the profession and presenting it as a solution to financial hardship. Characteristics of exotic dance clubs, such as immediate hire and daily pay, attracted women in a state of financial vulnerability. Women's motivations for dancing, including economic vulnerability and drug use practices, shaped their STI/HIV risk once immersed in the club environment, with social networks often facilitating sexual risk behavior. Understanding the factors that drive women to exotic dance and influence risk behavior in the club may assist in the development of targeted harm reduction interventions for exotic dancers. PMID:25807063

  9. Exotic pediculosis and hair-loss syndrome in deer (Odocoileus hemionus) populations in California.

    PubMed

    Roug, Annette; Swift, Pamela; Puschner, Birgit; Gerstenberg, Greg; Mertins, James W; Johnson, Christine Kreuder; Torres, Steve; Mortensen, Jack; Woods, Leslie

    2016-07-01

    Infestation with nonnative, "exotic" lice was first noted in Washington black-tailed deer (Odocoileus hemionus columbianus) in 1994 and has since then spread throughout the western United States. In California, infestation with the exotic louse Damalinia (Cervicola) sp. was first detected in black-tailed deer from northern California in 2004, and, in 2009, the exotic louse species Bovicola tibialis and Linognathus africanus were identified on mule deer (Odocoileus hemionus californicus) in central Sierra Nevada in association with a mortality event. Exotic lice have since been detected in various locations throughout the state. We describe the geographic distribution of these exotic lice within California, using data from 520 live-captured and 9 postmortem-sampled, free-ranging mule deer examined between 2009 and 2014. Data from live-captured deer were used to assess possible associations between louse infestation and host age, host sex, migratory behavior, season, and blood selenium and serum copper concentrations. Damalinia (Cervicola) sp. and B. tibialis lice were distinctively distributed geographically, with D. (Cervicola) sp. infesting herds in northern and central coastal California, B. tibialis occurring in the central coastal mountains and the Sierra Nevada, and L. africanus occurring only sporadically. Younger age classes and low selenium concentrations were significantly associated with exotic louse infestation, whereas no significant relationship was detected with serum copper levels. Our results show that exotic lice are widespread in California, and younger age classes with low blood selenium concentrations are more likely to be infested with lice than older deer.

  10. Exotic Dance in Baltimore: From Entry to STI/HIV Risk.

    PubMed

    Lilleston, Pamela S; Reuben, Jacqueline; Sherman, Susan G

    2015-01-01

    Research has documented health risks associated with sex work, but few U.S. studies have focused on the exotic dance industry. We undertook this study to describe the factors that influenced women's entry into exotic dance and explored the relation of these forces to their subsequent sexually transmitted infection (STI)/HIV risk trajectory. Qualitative interviews (N = 25) were conducted with female exotic dancers from June through August 2009. Data were analyzed through Atlas-ti using an inductive approach. Economic vulnerability was the primary force behind women's initiation into the profession. Drug use, physical abuse, and enjoyment of dancing were often concurrent with economic need and provided a further push toward exotic dance. Social networks facilitated entry by normalizing the profession and presenting it as a solution to financial hardship. Characteristics of exotic dance clubs, such as immediate hire and daily pay, attracted women in a state of financial vulnerability. Women's motivations for dancing, including economic vulnerability and drug use practices, shaped their STI/HIV risk once immersed in the club environment, with social networks often facilitating sexual risk behavior. Understanding the factors that drive women to exotic dance and influence risk behavior in the club may assist in the development of targeted harm reduction interventions for exotic dancers.

  11. Nuclear Medicine.

    ERIC Educational Resources Information Center

    Badawi, Ramsey D.

    2001-01-01

    Describes the use of nuclear medicine techniques in diagnosis and therapy. Describes instrumentation in diagnostic nuclear medicine and predicts future trends in nuclear medicine imaging technology. (Author/MM)

  12. Ecological engineering by a native leaf-cutting ant increases the performance of exotic plant species.

    PubMed

    Farji-Brener, Alejandro G; Lescano, Natalia; Ghermandi, Luciana

    2010-05-01

    Numerous mechanisms are proposed to explain why exotic plants successfully invade natural communities. However, the positive effects of native engineers on exotic plant species have received less consideration. We tested whether the nutrient-rich soil patches created by a native ecological engineer (refuse dumps from the leaf-cutting ant Acromyrmex lobicornis) increase the performance of exotic more than native plants. In a greenhouse experiment, individuals from several native and exotic species were planted in pots with refuse dumps (RDs) and non-nest soils (NNSs). Total plant biomass and foliar nutrient content were measured at the end of the experiment. We also estimated the cover of exotic and native plant species in external RDs from 54 field ant nests and adjacent areas. Greenhouse plants showed more biomass and foliar nutrient content in RDs than in NNS pots. Nevertheless, differences in the final mean biomass among RD and NNS plants were especially great in exotics. Accordingly, the cover of exotic plants was higher in field RDs than in adjacent, non-nest soils. Our results demonstrated that plants can benefit from the enhanced nutrient content of ant RDs, and that A. lobicornis acts as an ecosystem engineer, creating a substrate that especially increases the performance of exotics. This supports the fluctuating resource hypothesis as a mechanism to promote biological invasions, and illustrates how this hypothesis may operate in nature. Since ant nests and exotic plants are more common in disturbed than in pristine environments, the role of ant nests in promoting biological invasions might be of particular interest. Proposals including the use of engineer species to restore disturbed habitats should be planned with caution because of their potential role in promoting invasions.

  13. Herbivory and dominance shifts among exotic and congeneric native plant species during plant community establishment.

    PubMed

    Engelkes, Tim; Meisner, Annelein; Morriën, Elly; Kostenko, Olga; Van der Putten, Wim H; Macel, Mirka

    2016-02-01

    Invasive exotic plant species often have fewer natural enemies and suffer less damage from herbivores in their new range than genetically or functionally related species that are native to that area. Although we might expect that having fewer enemies would promote the invasiveness of the introduced exotic plant species due to reduced enemy exposure, few studies have actually analyzed the ecological consequences of this situation in the field. Here, we examined how exposure to aboveground herbivores influences shifts in dominance among exotic and phylogenetically related native plant species in a riparian ecosystem during early establishment of invaded communities. We planted ten plant communities each consisting of three individuals of each of six exotic plant species as well as six phylogenetically related natives. Exotic plant species were selected based on a rapid recent increase in regional abundance, the presence of a congeneric native species, and their co-occurrence in the riparian ecosystem. All plant communities were covered by tents with insect mesh. Five tents were open on the leeward side to allow herbivory. The other five tents were completely closed in order to exclude insects and vertebrates. Herbivory reduced aboveground biomass by half and influenced which of the plant species dominated the establishing communities. Exposure to herbivory did not reduce the total biomass of natives more than that of exotics, so aboveground herbivory did not selectively enhance exotics during this early stage of plant community development. Effects of herbivores on plant biomass depended on plant species or genus but not on plant status (i.e., exotic vs native). Thus, aboveground herbivory did not promote the dominance of exotic plant species during early establishment of the phylogenetically balanced plant communities.

  14. Native weeds and exotic plants: Relationships to disturbance in mixed-grass prairie

    USGS Publications Warehouse

    Larson, D.L.

    2003-01-01

    Disturbance frequently is implicated in the spread of invasive exotic plants. Disturbances may be broadly categorized as endogenous (e.g., digging by fossorial animals) or exogenous (e.g., construction and maintenance of roads and trails), just as weedy species may be native or exotic in origin. The objective of this study was to characterize and compare exotic and native weedy plant occurrence in and near three classes of disturbance -digging by prairie dogs (an endogenous disturbance to which native plants have had the opportunity to adapt), paved or gravel roads (an exogenous disturbance without natural precedent), and constructed trails (an exogenous disturbance with a natural precedent in trails created by movement of large mammals) - in three geographically separate national park units. I used plant survey data from the North and South Units of Theodore Roosevelt National Park and Wind Cave National Park in the northern mixed-grass prairie of western North and South Dakota, USA, to characterize the distribution of weedy native and exotic plants with respect to the three disturbance classes as well as areas adjacent to them. There were differences both in the susceptibility of the disturbance classes to invasion and in the distributions of native weeds and exotic species among the disturbance classes. Both exotic and native weedy species richness were greatest in prairie dog towns and community composition there differed most from undisturbed areas. Exotic species were more likely to thrive near roadways, where native weedy species were infrequently encountered. Exotic species were more likely to have spread beyond the disturbed areas into native prairie than were weedy native species. The response of individual exotic plant species to the three types of disturbance was less consistent than that of native weedy species across the three park units.

  15. Antisymmetrized molecular dynamics studies for exotic clustering phenomena in neutron-rich nuclei

    NASA Astrophysics Data System (ADS)

    Kimura, M.; Suhara, T.; Kanada-En'yo, Y.

    2016-12-01

    We present a review of recent works on clustering phenomena in unstable nuclei studied by antisymmetrized molecular dynamics (AMD). The AMD studies in these decades have uncovered novel types of clustering phenomena brought about by the excess neutrons. Among them, this review focuses on the molecule-like structure of unstable nuclei. One of the earliest discussions on the clustering in unstable nuclei was made for neutron-rich Be and B isotopes. AMD calculations predicted that the ground state clustering is enhanced or reduced depending on the number of excess neutrons. Today, the experiments are confirming this prediction as the change of the proton radii. Behind this enhancement and reduction of the clustering, there are underlying shell effects called molecular and atomic orbits. These orbits form covalent and ionic bonding of the clusters analogous to the atomic molecules. It was found that this "molecular-orbit picture" reasonably explains the low-lying spectra of Be isotopes. The molecular-orbit picture is extended to other systems having parity asymmetric cluster cores and to the three cluster systems. O and Ne isotopes are the candidates of the former, while the 3 α linear chains in C isotopes are the latter. For both subjects, many intensive studies are now in progress. We also pay a special attention to the observables which are the fingerprint of the clustering. In particular, we focus on the monopole and dipole transitions which are recently regarded as good probe for the clustering. We discuss how they have and will reveal the exotic clustering.

  16. Are bison exotic in the Wrangell-St. Elias National Park and Preserve?

    NASA Astrophysics Data System (ADS)

    Peek, James M.; Miquelle, Dale G.; Wright, R. Gerald

    1987-03-01

    The effect of past distributions of animal populations now extinct in an area from unknown causes is considered relative to their status as exotic or native in national parks. The example is the bison (Bison bison) on the Copper and Chitina river drainages in Alaska in the USA which was introduced prior to establishment of Wrangell-St. Elias National Park and Preserve. The fossil record suggests that bison were present as recently as 500 years ago in Alaska. The policy of the US National Park Service to maintain natural ecosystems and restrict or eliminate exotic species raises the issue of whether this species should be treated as exotic or native.

  17. Exotic radiation from a photonic crystal excited by an ultrarelativistic electron beam.

    PubMed

    Horiuchi, N; Ochiai, T; Inoue, J; Segawa, Y; Shibata, Y; Ishi, K; Kondo, Y; Kanbe, M; Miyazaki, H; Hinode, F; Yamaguti, S; Ohtaka, K

    2006-11-01

    We report the observation of an exotic radiation (unconventional Smith-Purcell radiation) from a one-dimensional photonic crystal. The physical origin of the exotic radiation is direct excitation of the photonic bands by an ultrarelativistic electron beam. The spectrum of the exotic radiation follows photonic bands of a certain parity, in striking contrast to the conventional Smith-Purcell radiation, which shows solely a linear dispersion. Key ingredients for the observation are the facts that the electron beam is in an ultrarelativistic region and that the photonic crystal is finite. The origin of the radiation was identified by comparison of experimental and theoretical results.

  18. Vermicomposting of Solid Waste Using Local and Exotic Earthworms: A Comparative Study.

    PubMed

    Amit, Krishan; Ajit, Kumar; Arthanareeswari, M; Kamaraj, P

    2014-07-01

    The aim of this study was to assess the decomposition efficiency of earthworms, local (L.mauritii) as well as exotic (Eisenia foetida) in vermicomposting of garden litter in SRM University campus. The vermicompost produced through vermicomposting of garden litter mixed with cow dung in the ratio of 3:1 by using local and exotic earthworms (Eisenia foetida) was rich in ammoniacal nitrogen, nitrate nitrogen, available phosphorus, total potassium and TKN, and there was a reduction in total organic carbon and carbon to nitrogen ratio. The study reveals that the decomposition efficiency of exotic earthworms is better compared to local earthworms.

  19. Hyperpolarized NMR Probes for Biological Assays

    PubMed Central

    Meier, Sebastian; Jensen, Pernille R.; Karlsson, Magnus; Lerche, Mathilde H.

    2014-01-01

    During the last decade, the development of nuclear spin polarization enhanced (hyperpolarized) molecular probes has opened up new opportunities for studying the inner workings of living cells in real time. The hyperpolarized probes are produced ex situ, introduced into biological systems and detected with high sensitivity and contrast against background signals using high resolution NMR spectroscopy. A variety of natural, derivatized and designed hyperpolarized probes has emerged for diverse biological studies including assays of intracellular reaction progression, pathway kinetics, probe uptake and export, pH, redox state, reactive oxygen species, ion concentrations, drug efficacy or oncogenic signaling. These probes are readily used directly under natural conditions in biofluids and are often directly developed and optimized for cellular assays, thus leaving little doubt about their specificity and utility under biologically relevant conditions. Hyperpolarized molecular probes for biological NMR spectroscopy enable the unbiased detection of complex processes by virtue of the high spectral resolution, structural specificity and quantifiability of NMR signals. Here, we provide a survey of strategies used for the selection, design and use of hyperpolarized NMR probes in biological assays, and describe current limitations and developments. PMID:24441771

  20. Ability of a Generalist Seed Beetle to Colonize an Exotic Host: Effects of Host Plant Origin and Oviposition Host.

    PubMed

    Amarillo-Suárez, A; Repizo, A; Robles, J; Diaz, J; Bustamante, S

    2017-02-02

    The colonization of an exotic species by native herbivores is more likely to occur if that herbivore is a generalist. There is little information on the life-history mechanisms used by native generalist insects to colonize exotic hosts and how these mechanisms are affected by host properties. We examined the ability of the generalist seed beetle Stator limbatus Horn to colonize an exotic species. We compared its host preference, acceptability, performance, and egg size when ovipositing and developing on two native (Pithecellobium dulce (Roxb.) Benth and Senegalia riparia (Kunth)) and one exotic legume species (Leucaena leucocephala (Lam.)). We also analyzed the seed chemistry. We found that females recognize the exotic species as an unfavorable host for larval development and that they delayed oviposition and laid fewer and larger eggs on the exotic species than on the native species. Survivorship on the exotic host was 0%. Additionally, seeds of the native species contain five chemical compounds that are absent in the exotic species, and the exotic species contains three sterols, which are absent in the native legumes. Genetically based differences between beetles adapted to different hosts, plastic responses toward new hosts, and chemical differences among seeds are important in host colonization and recognition of the exotic host. In conclusion, the generalist nature of S. limbatus does not influence its ability to colonize L. leucocephala. Explanations for the colonization of exotic hosts by generalist native species and for the success of invasive species must be complemented with studies measuring local adaptation and plasticity.

  1. Hot-wire probe

    NASA Technical Reports Server (NTRS)

    Mikulla, V.

    1976-01-01

    High-temperature platinum probe measures turbulence and Reynolds shear stresses in high-temperature compressible flows. Probe does not vibrate at high velocities and does not react like strain gage on warmup.

  2. Galileo Probe Battery System

    NASA Technical Reports Server (NTRS)

    Dagarin, B. P.; Taenaka, R. K.; Stofel, E. J.

    1997-01-01

    The conclusions of the Galileo probe battery system are: the battery performance met mission requirements with margin; extensive ground-based and flight tests of batteries prior to probe separation from orbiter provided good prediction of actual entry performance at Jupiter; and the Li-SO2 battery was an important choice for the probe's main power.

  3. A Magnetoresistance Measuring Probe.

    DTIC Science & Technology

    The in line four point probe, commonly used for measuring the sheet resistance in a conductor, cannot measure the anisotropic ferromagnetic magnetoresistance. However, the addition of two contact points that are not collinear with the current contacts give the probe the ability to non-destructively measure the anistropic magnetoresistance. Keywords: Magnetoresistance; Anisotropic; Thin-Film; Permalloy; Four Point Probe; Anisotropic Resistance.

  4. Changing Facets of Nuclear Structure

    NASA Astrophysics Data System (ADS)

    Covello, Aldo

    2008-04-01

    Section I. Exotic nuclear structure. Radioactive beams at TRIUMF / A. C. Shotter. Status of RI-beam factory project at RIKEN / H. Ueno. Population of neutron unbound states via two-proton knockout reactions / N. Frank ... [et al.]. Studies of neutron-rich nuclei using ISOL facilities at CERN and Jyväskylä / J. Äystö. Shell structure evolution far from stability: recent results from GANIL / F. Azaiez. Magnetic moment meaurements: pushing the limits / N. Benczer-Koller. Technique for measuring angular correlations and g-factors of excited states with large multi-detector arrays: an application to neutron rich nuclei produced in spontaneous fission / A. V. Ramayya ... [et al.]. Isospin symmetry and proton decay: identification of the 10+ isomer in [symbol]Ni / C. Fahlander ... [et al.]. Exploring the evolution of the shell structure by means of deep inelastic reactions / G. de Angelis. Studies on the exotic structure of [symbol]Al by measurements of [symbol] and P[symbol] / D. Q. Fang ... [et al.]. Extended cluster model for light and medium nuclei / M. Tomaselli ... [et al.]. Nuclear structure studies on exotic nuclei with radioactive beams - present status and future perspectives at FAIR / P. Egelhof. The SPES direct target project at the Laboratori Nazionali di Legnaro / G. Prete ... [et al.] -- Section II. Nuclear structure and nuclear forces. Modern aspects of nuclear structure theory / J. Wambach. Correlations in nuclei: a review / R. Schiavilla. Correlated nucleons in k- and r-space / I. Sick. Roles of all-order core polarizations and Brown-Rho scaling in nucleon effective interactions / T. T. S. Kuo ... [et al.]. Ab initio and ab exitu no core shell model / J. P. Vary ... [et al.]. Ab-initio coupled cluster theory for open quantum systems / G. Hagen ... [et al.]. Symplectic no-core shell model / J. P. Draayer ... [et al.]. Role of deformed symplectic configurations in ab initio no-core shell model results / T. Dytrych ... [et al.]. Nuclear structure

  5. Gamma-Ray Imaging Probes.

    NASA Astrophysics Data System (ADS)

    Wild, Walter James

    1988-12-01

    External nuclear medicine diagnostic imaging of early primary and metastatic lung cancer tumors is difficult due to the poor sensitivity and resolution of existing gamma cameras. Nonimaging counting detectors used for internal tumor detection give ambiguous results because distant background variations are difficult to discriminate from neighboring tumor sites. This suggests that an internal imaging nuclear medicine probe, particularly an esophageal probe, may be advantageously used to detect small tumors because of the ability to discriminate against background variations and the capability to get close to sites neighboring the esophagus. The design, theory of operation, preliminary bench tests, characterization of noise behavior and optimization of such an imaging probe is the central theme of this work. The central concept lies in the representation of the aperture shell by a sequence of binary digits. This, coupled with the mode of operation which is data encoding within an axial slice of space, leads to the fundamental imaging equation in which the coding operation is conveniently described by a circulant matrix operator. The coding/decoding process is a classic coded-aperture problem, and various estimators to achieve decoding are discussed. Some estimators require a priori information about the object (or object class) being imaged; the only unbiased estimator that does not impose this requirement is the simple inverse-matrix operator. The effects of noise on the estimate (or reconstruction) is discussed for general noise models and various codes/decoding operators. The choice of an optimal aperture for detector count times of clinical relevance is examined using a statistical class-separability formalism.

  6. Exotic Hybrid Meson Spectroscopy with the GlueX detector at Jlab

    SciTech Connect

    Lawrence, David W.

    2014-03-01

    The GlueX experiment is scheduled to begin taking data in 2015. The goal is to discover evidence for the existence of exotic hybrid mesons and to map out their spectrum in the light quark sector. Recent theoretical developments using Lattice QCD predict exotic hybrid states in a mass range accessible using the newly upgraded 12GeV electron accelerator at Jefferson Lab. Hybrid mesons, and in particular exotic hybrid mesons, provide the ideal laboratory for testing QCD in the confinement regime since these mesons explicitly manifest the gluonic degrees of freedom. The experiment will use 9 GeV linearly polarized photons produced via coherent bremsstrahlung to produce the exotic hybrids. The decay products will be detected in the solenoid-based GlueX detector currently under construction at Jefferson Lab. The status of the GlueX experiment including detector parameters will be presented along with theoretical motivation for the experiment.

  7. The role of exotic species in homogenizing the North American flora.

    PubMed

    Qian, Hong; Ricklefs, Robert E

    2006-12-01

    Exotic species have begun to homogenize the global biota, yet few data are available to assess the extent of this process or factors that constrain its advance at global or continental scales. We evaluate homogenization of vascular plants across America north of Mexico by comparing similarity in the complete native and exotic floras between states and provinces of the USA and Canada. Compared with native species, exotic plants are distributed haphazardly among areas but spread more widely, producing differentiation of floras among neighbouring areas but homogenization at greater distance. The number of exotic species is more closely associated with the size of the human population than with ecological conditions, as in the case of native species, and their distributions are less influenced by climate than those of native species.

  8. Apparent competition and native consumers exacerbate the strong competitive effect of an exotic plant species.

    PubMed

    Orrock, John L; Dutra, Humberto P; Marquis, Robert J; Barber, Nicholas

    2015-04-01

    Direct and indirect effects can play a key role in invasions, but experiments evaluating both are rare. We examined the roles of direct competition and apparent competition by exotic Amur honeysuckle (Lonicera maackii) by manipulating (1) L. maackii vegetation, (2) presence of L. maackii fruits, and (3) access to plants by small mammals and deer. Direct competition with L. maackii reduced the abundance and richness of native and exotic species, and native consumers significantly reduced the abundance and richness of native species. Although effects of direct competition and consumption were more pervasive, richness of native plants was also reduced through apparent competition, as small-mammal consumers reduced richness only when L. maackii fruits were present. Our experiment reveals the multiple, interactive pathways that affect the success and impact of an invasive exotic plant: exotic plants may directly benefit from reduced attack by native consumers, may directly exert strong competitive effects on native plants, and may also benefit from apparent competition.

  9. Allergic contact dermatitis from exotic woods: importance of patch-testing with patient-provided samples.

    PubMed

    Podjasek, Joshua O; Cook-Norris, Robert H; Richardson, Donna M; Drage, Lisa A; Davis, Mark D P

    2011-01-01

    Exotic woods from tropical and subtropical regions (eg, from South America, south Asia, and Africa) frequently are used occupationally and recreationally by woodworkers and hobbyists. These exotic woods more commonly provoke irritant contact dermatitis reactions, but they also can provoke allergic contact dermatitis reactions. We report three patients seen at Mayo Clinic (Rochester, MN) with allergic contact dermatitis reactions to exotic woods. Patch testing was performed and included patient-provided wood samples. Avoidance of identified allergens was recommended. For all patients, the dermatitis cleared or improved after avoidance of the identified allergens. Clinicians must be aware of the potential for allergic contact dermatitis reactions to compounds in exotic woods. Patch testing should be performed with suspected woods for diagnostic confirmation and allowance of subsequent avoidance of the allergens.

  10. Exotic clusters in an unbound region of light neutron-rich systems

    NASA Astrophysics Data System (ADS)

    Ito, Makoto

    2009-10-01

    In light neutron-rich systems, many kinds of molecular structures are discussed from the view point of the clustering phenomena.In particular, much attention has been concentrated on Be isotopes. The molecular orbital (MO), such as &-circ; and &+circ; associated with the covalent binding of atomic molecules, have been shown to give a good description for the low-lying states of these isotopes. In their highly-excited states, furthermore, recent experiments revealed the existence of the interesting resonant states which dominantly decay to the ^6,8He fragments. In this report, we show the unified study of the exotic structures of ^12Be=α+α+4N in an unbound region and the α+^6,8He resonant scattering. We applied the generalized two-center cluster model in which the covalent MO and the atomic orbital (AO) configurations with ^xHe+^yHe could be described in a unified manner. First, we calculated the energy spectra below an α decay-threshold. The (π32^-)^2 (σ12^+)^2 configuration corresponding to ν(0p)^4(sd)^2 becomes the ground state, while (π3 2^-)^2(π12^-)^2 having a large overlap with ν(0p)^6 appears as the first excited state. The rotational band of the ground state reaches to the maximum spin of J^π = 8^+. This result means that the magicity of N=8 is broken in ^12Be due to the formation of (π3 2^-)^2(σ12^+)^2. Next, we solved the scattering problem of α+^8He and identified the several resonance poles. In the continuum region, we found the rotational bands having the AO configurations of α+^8He, ^6He+^6He, and ^5He+^7 He. Furthermore, a much more exotic band appears in the same energy region. In this band, two valence neutrons are localized at individual α-cores (the ^5He+^5He cluster), while the other two neutrons form the covalent &+circ;- bonding between two ^5He clusters; hence, it has a ``hybrid structure'' between the MO configuration and the AO one. In the J^π=0^+ state, it is strongly excited by the two-neutron transfer reaction, α+^8He

  11. Synthesis of Exotic Soaps in the Chemistry Laboratory

    NASA Astrophysics Data System (ADS)

    Phanstiel, Otto, IV; Dueno, Eric; Xianghong Wang, Queenie

    1998-05-01

    A variety of different triglyceride sources ranging from Vietnamese garlic oil to a local restaurant's grill sludge were saponified to generate a series of exotic soaps. Students did not quantify their results, but described their products in terms of color, texture and odor. Their results were compared with existing data on the triglyceride content for each source used (when possible). Soap texture seemed to be related to the degree of unsaturation present in the starting triglyceride. However, texture alterations due to occluded impurities could not be ruled out. In general, fats and oils high in saturated fats (butter) gave hard, chunky, and waxlike soaps, while those high in unsaturated fats gave flaky and easily crumbled soaps (olive, corn, peanut and sunflower oils). Soap color was not consistent with triglyceride unsaturation levels during the time frame studied. Odor changes were dramatic and were explained in terms of a change in chemical structure (i.e. conversion from an ester to a carboxylate salt). In general, the experiment was well received by students and stressed the importance of making precise qualitative observations during the experiment.

  12. A universal explanation of tunneling conductance in exotic superconductors

    PubMed Central

    Hong, Jongbae; Abergel, D. S. L.

    2016-01-01

    A longstanding mystery in understanding cuprate superconductors is the inconsistency between the experimental data measured by scanning tunneling spectroscopy (STS) and angle-resolved photoemission spectroscopy (ARPES). In particular, the gap between prominent side peaks observed in STS is much bigger than the superconducting gap observed by ARPES measurements. Here, we reconcile the two experimental techniques by generalising a theory which was previously applied to zero-dimensional mesoscopic Kondo systems to strongly correlated two-dimensional (2D) exotic superconductors. We show that the side peaks observed in tunneling conductance measurements in all these materials have a universal origin: They are formed by coherence-mediated tunneling under bias and do not directly reflect the underlying density of states (DOS) of the sample. We obtain theoretical predictions of the tunneling conductance and the density of states of the sample simultaneously and show that for cuprate and pnictide superconductors, the extracted sample DOS is consistent with the superconducting gap measured by ARPES. PMID:27511315

  13. Experimental constraints on the exotic shearing of space-time

    NASA Astrophysics Data System (ADS)

    Richardson, Jonathan William

    The Holometer program is a search for first experimental evidence that space-time has quantum structure. The detector consists of a pair of co-located 40-m power-recycled interferometers whose outputs are read out synchronously at 50 MHz, achieving sensitivity to spatially-correlated fluctuations in differential position on time scales shorter than the light-crossing time of the instruments. Unlike gravitational wave interferometers, which time-resolve transient geometrical disturbances in the spatial background, the Holometer is searching for a universal, stationary quantization noise of the background itself. This dissertation presents the final results of the Holometer Phase I search, an experiment configured for sensitivity to exotic coherent shearing fluctuations of space-time. Measurements of high-frequency cross-spectra of the interferometer signals obtain sensitivity to spatially-correlated effects far exceeding any previous measurement, in a broad frequency band extending to 7.6 MHz, twice the inverse light-crossing time of the apparatus. This measurement is the statistical aggregation of 2.1 petabytes of 2-byte differential position measurements obtained over a month-long exposure time. At 3-sigma significance, it places an upper limit on the coherence scale of spatial shear two orders of magnitude below the Planck length. The result demonstrates the viability of this novel spatially-correlated interferometric detection technique to reach unprecedented sensitivity to coherent deviations of space-time from classicality, opening the door for direct experimental tests of theories of relational quantum gravity.

  14. Role of container vessels in the introduction of exotic species.

    PubMed

    Niimi, Arthur J

    2004-11-01

    Ballast water exchange practices were monitored on 28 incoming container vessels at the Port of Montreal. Measurements on 15 vessels indicated 13 of 32 tanks had salinities of <30 per thousand. The 16 transits with a North Atlantic route visited 31 of 37 ports located on freshwater or near freshwater outflows. Ballast carried by this vessel type represents an important means for the introduction of species on a global scale because of its transit routes, dockside discharge and moving ballast between tanks. Container vessels represent about 15% of the world fleet, but account for 32% of all visits to global ports, and 46% of visits to the 25 largest ports. The 10 ports that handled the largest volumes of international cargo also included 8 that handled the most cargo containers. Large ports can receive over 100,000 visits by all vessel types annually, and serve as hubs for over 500 ports in 100 countries. Secondary transport of exotic species is also a concern because of frequent visits by regional vessels.

  15. Exotic X-ray Sources from Intermediate Energy Electron Beams

    SciTech Connect

    Chouffani, K.; Wells, D.; Harmon, F.; Jones, J.L.; Lancaster, G.

    2003-08-26

    High intensity x-ray beams are used in a wide variety of applications in solid-state physics, medicine, biology and material sciences. Synchrotron radiation (SR) is currently the primary, high-quality x-ray source that satisfies both brilliance and tunability. The high cost, large size and low x-ray energies of SR facilities, however, are serious limitations. Alternatively, 'novel' x-ray sources are now possible due to new small linear accelerator (LINAC) technology, such as improved beam emittance, low background, sub-Picosecond beam pulses, high beam stability and higher repetition rate. These sources all stem from processes that produce Radiation from relativistic Electron beams in (crystalline) Periodic Structures (REPS), or the periodic 'structure' of laser light. REPS x-ray sources are serious candidates for bright, compact, portable, monochromatic, and tunable x-ray sources with varying degrees of polarization and coherence. Despite the discovery and early research into these sources over the past 25 years, these sources are still in their infancy. Experimental and theoretical research are still urgently needed to answer fundamental questions about the practical and ultimate limits of their brightness, mono-chromaticity etc. We present experimental results and theoretical comparisons for three exotic REPS sources. These are Laser-Compton Scattering (LCS), Channeling Radiation (CR) and Parametric X-Radiation (PXR)

  16. Properties of the exotic metastable ST12 germanium allotrope

    PubMed Central

    Zhao, Zhisheng; Zhang, Haidong; Kim, Duck Young; Hu, Wentao; Bullock, Emma S.; Strobel, Timothy A.

    2017-01-01

    The optical and electronic properties of semiconducting materials are of great importance to a vast range of contemporary technologies. Diamond-cubic germanium is a well-known semiconductor, although other ‘exotic' forms may possess distinct properties. In particular, there is currently no consensus for the band gap and electronic structure of ST12-Ge (tP12, P43212) due to experimental limitations in sample preparation and varying theoretical predictions. Here we report clear experimental and theoretical evidence for the intrinsic properties of ST12-Ge, including the first optical measurements on bulk samples. Phase-pure bulk samples of ST12-Ge were synthesized, and the structure and purity were verified using powder X-ray diffraction, transmission electron microscopy, Raman and wavelength/energy dispersive X-ray spectroscopy. Optical measurements indicate that ST12-Ge is a semiconductor with an indirect band gap of 0.59 eV and a direct optical transition at 0.74 eV, which is in good agreement with electrical transport measurements and our first-principles calculations. PMID:28045027

  17. Experimental evidence for the exotic dibaryon d^{ast }1

    NASA Astrophysics Data System (ADS)

    Khrykin, A. S.

    2016-12-01

    We provide strong experimental evidence for the existence of a nonstrange exotic dibaryon with a mass of about 1956 MeV called d^{ast }1(1956). This dibaryon is expected to be stable against strong decay and decays predominantly into two nucleons ( NN) via the isospin-conserving radiative process d^{ast }1 to NN γ . First, we present the experimental evidence for the d^{ast }1(1956) found in the energy spectrum of the coincident photons emitted at ±900 from the reaction p p → p p γ γ at 216 MeV. Then we give an explanation why the WASA/CELSIUS Collaboration did not find signatures of this dibaryon in its proton-proton bremsstrahlung data measured at 310 and 200 MeV. We also present signatures of this dibaryon found in experimental invariant mass spectra of photon pairs from the p p → p p γ γ reaction measured by this collaboration at 1360 and 1200 MeV. These signatures provide very substantial confirmation of the existence of the d^{ast }1(1956).

  18. Use of seeded exotic grasslands by wintering birds

    USGS Publications Warehouse

    George, Andrew D.; O'Connell, Timothy J.; Hickman, Karen R.; Leslie,, David M.

    2013-01-01

    Despite widespread population declines of North American grassland birds, effects of anthropogenic disturbance of wintering habitat of this guild remain poorly understood. We compared avian abundance and habitat structure in fields planted by the exotic grass Old World bluestem (Bothriochloa ischaemum; OWB) to that in native mixed-grass prairie. During winters of 2007-2008 and 2008-2009, we conducted bird and vegetation surveys in six native grass and six OWB fields in Garfield, Grant, and Alfalfa counties, Oklahoma. We recorded 24 species of wintering birds in native fields and 14 species in OWB monocultures. While vegetation structure was similar between field types, abundance of short-eared owls (Asio flammeus), northern harriers (Circus cyaneus) and Smith's longspurs (Calcarius pictus) was higher in OWB fields during at least one year. The use of OWB fields by multiple species occupying different trophic positions suggested that vegetation structure of OWB can meet habitat requirements of some wintering birds, but there is insufficient evidence to determine if it provides superior conditions to native grasses.

  19. Compact high resolution isobar separator for study of exotic decays

    NASA Astrophysics Data System (ADS)

    Shchepunov, V.; Piechaczek, A.; Carter, H. K.; Batchelder, J. C.; Zganjar, E. F.

    2009-05-01

    A compact isobar separator, based on the Multi-Pass-Time-of-Flight (MTOF) principle, is developed. A mass resolving power (MRP) of 110,000 (FWHM) is achieved as spectrometer with a transmission of 50 - 80%. The transverse beam acceptance and the energy acceptance are 42 π mm mrad and about ± 2.5%. Operated as a separator, molecules of N2 and CO with δM/M = 1/2500 or 10.433 MeV were separated with a Bradbury Nielsen gate. In that mode of operation, the MRP (FWHM) is about 40,000 after 120 laps. To inject radioactive ion beams into the separator, and to further improve its MRP, cooler and buncher RF quadrupoles were designed^1 and tested. A bunch width of 30 ns at 1% of the peak height (FWHM = 9 ns) and a transmission in DC mode of 75 -- 80 % were achieved. With such bunch parameters, MRPs of ˜ 400,000 (FWHM) are expected for the MTOF separator. At HRIBF, it will provide pure samples of exotic nuclides around ^100Sn, of neutron deficient rare-earth nuclei and of neutron-rich nuclei. Incidental measurements of mass differences will determine Qβ values with accuracies of ˜ 1%. ^1 V. Shchepunov and V. Kozlovskiy et al., to be published

  20. Properties of the exotic metastable ST12 germanium allotrope

    NASA Astrophysics Data System (ADS)

    Zhao, Zhisheng; Zhang, Haidong; Kim, Duck Young; Hu, Wentao; Bullock, Emma S.; Strobel, Timothy A.

    2017-01-01

    The optical and electronic properties of semiconducting materials are of great importance to a vast range of contemporary technologies. Diamond-cubic germanium is a well-known semiconductor, although other `exotic' forms may possess distinct properties. In particular, there is currently no consensus for the band gap and electronic structure of ST12-Ge (tP12, P43212) due to experimental limitations in sample preparation and varying theoretical predictions. Here we report clear experimental and theoretical evidence for the intrinsic properties of ST12-Ge, including the first optical measurements on bulk samples. Phase-pure bulk samples of ST12-Ge were synthesized, and the structure and purity were verified using powder X-ray diffraction, transmission electron microscopy, Raman and wavelength/energy dispersive X-ray spectroscopy. Optical measurements indicate that ST12-Ge is a semiconductor with an indirect band gap of 0.59 eV and a direct optical transition at 0.74 eV, which is in good agreement with electrical transport measurements and our first-principles calculations.

  1. Exotic electronic properties in Thue-Morse graphene superlattices.

    PubMed

    Xu, Yafang; Zou, Jianfei; Jin, Guojun

    2013-06-19

    To show the specific behavior of Dirac fermions in a quasi-periodic structure, we investigate the electronic properties in a deterministic Thue-Morse graphene superlattice. Our main findings include the following. (i) Unlike conventional Schrödinger electrons, quasi-periodic features such as the striking self-similarity and trifurcation in the transmission spectrum can be manifested only at oblique incidence. (ii) In the vicinity of the usual Dirac point, extra Dirac points emerge; their locations are dependent merely on the second generation of the Thue-Morse structure and the number is double that in the periodic graphene superlattice. (iii) A classification is given about the wavefunctions in the Thue-Morse structure which are transformed from the critical states into extended ones at the Dirac points. (iv) The electrons can transmit perfectly at the extra Dirac points, and such a collimation supplies a convenient way to experimentally detect the numbers and the locations of the extra Dirac points. These exotic electronic properties in the aperiodic graphene superlattices may facilitate some applications in graphene-based electronics.

  2. Biomanagement of petrochemical sludge using an exotic earthworm Eudrilus eugineae.

    PubMed

    Banu, J Rajesh; Esakkiraj, S; Nagendran, R; Logakanthi, S

    2005-01-01

    Petrochemical industry have severe problem in disposing effluent and semisolid sludge despite repeated recycling. It requires further treatment prior to disposal of sludge. In recent years biological treatment methods received much attention and considered as an efficient low-cost treatment. One such method is vermiculture treatment The end product of vermicompost is rich in essential micro and macronutrients along with microorganisms in a very simple form. Adding cast, not only improves the soil structure and fertility but also leads to improvement in overall plant growth and thus increase their yield. The present study was carried out to dispose the petrochemical sludge biologically using an exotic earthworm Eudrilus eugineae. The petrochemical sludge at various concentrations 25, 50 and 75% were subjected to vermicomposting treatment for a period of 60 days. During the period of study, data were collected on life form of earthworm and chemical analysis of the sludge before and after treatment. The microbial analysis was carried out fortnightly. The results indicate that 25 and 50% concentration of sludge was ideal for the vermicomposting, whereas the higher concentration inhibits the vermicomposting.

  3. Experimental Constraints of the Exotic Shearing of Space-Time

    SciTech Connect

    Richardson, Jonathan William

    2016-08-01

    The Holometer program is a search for rst experimental evidence that space-time has quantum structure. The detector consists of a pair of co-located 40-m power-recycled interferometers whose outputs are read out synchronously at 50 MHz, achieving sensitivity to spatiallycorrelated uctuations in dierential position on time scales shorter than the light-crossing time of the instruments. Unlike gravitational wave interferometers, which time-resolve transient geometrical disturbances in the spatial background, the Holometer is searching for a universal, stationary quantization noise of the background itself. This dissertation presents the nal results of the Holometer Phase I search, an experiment congured for sensitivity to exotic coherent shearing uctuations of space-time. Measurements of high-frequency cross-spectra of the interferometer signals obtain sensitivity to spatially-correlated eects far exceeding any previous measurement, in a broad frequency band extending to 7.6 MHz, twice the inverse light-crossing time of the apparatus. This measurement is the statistical aggregation of 2.1 petabytes of 2-byte dierential position measurements obtained over a month-long exposure time. At 3 signicance, it places an upper limit on the coherence scale of spatial shear two orders of magnitude below the Planck length. The result demonstrates the viability of this novel spatially-correlated interferometric detection technique to reach unprecedented sensitivity to coherent deviations of space-time from classicality, opening the door for direct experimental tests of theories of relational quantum gravity.

  4. Novel Fabrication and Simple Hybridization of Exotic Material MEMS

    SciTech Connect

    Datskos, P.G.; Rajic, S.

    1999-11-13

    Work in materials other than silicon for MEMS applications has typically been restricted to metals and metal oxides instead of more ''exotic'' semiconductors. However, group III-V and II-VI semiconductors form a very important and versatile collection of material and electronic parameters available to the MEMS and MOEMS designer. With these materials, not only are the traditional mechanical material variables (thermal conductivity, thermal expansion, Young's modulus, etc.) available, but also chemical constituents can be varied in ternary and quaternary materials. This flexibility can be extremely important for both friction and chemical compatibility issues for MEMS. In addition, the ability to continually vary the bandgap energy can be particularly useful for many electronics and infrared detection applications. However, there are two major obstacles associated with alternate semiconductor material MEMS. The first issue is the actual fabrication of non-silicon devices and the second impediment is communicating with these novel devices. We will describe an essentially material independent fabrication method that is amenable to most group III-V and II-VI semiconductors. This technique uses a combination of non-traditional direct write precision fabrication processes such as diamond turning, ion milling, laser ablation, etc. This type of deterministic fabrication approach lends itself to an almost trivial assembly process. We will also describe in detail the mechanical, electrical, and optical self-aligning hybridization technique used for these alternate-material MEMS.

  5. Exotic interactions among C-jets and Pb-jets

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The C-jets and Pb-jets were surveyed on the part of Chacaltaya emulsion chamber No.19 amounting to an exposure of 28.8 sq m yr. It is shown that the adopted events make up an unbiased sample of C-jets for sigma sub E gamma TeV. Mini-Centauro interaction gives the most natural explanation for the eight pinaught-less C-jets with three or more constituent shower core. Out of the eight double-cored pinaught-less events, three are found to have visible invariant masses 1.8 GeV/c. Three Pb-jets-lower are composed of double cores whose respective visible transverse momenta are greater than 0.5 GeV/c, suggesting that they are of Geminion origin or chiron origin. The energies of the parent particles are estimated to be 100 to 200 TeV for all three kinds of events. The implications of this energy estimate and the frequency of observed exotic events are discussed.

  6. Effects of exotic grasses on soil seed banks in Southeastern Arizona grasslands

    USGS Publications Warehouse

    McLaughlin, S.P.; Bowers, Janice E.

    2007-01-01

    At the Appleton-Whittell Research Ranch, an ungrazed grassland preserve in southeastern Arizona, soil seed banks were sampled in June, August, and October 2002 and June 2003. Wildfire had previously burned 90% of the research ranch in May 2002. Seed density and species richness in burned native grassland (2 plots) were compared to those in burned exotic grassland (2 plots). Averaged over 4 sample dates, seed densities were as follows: burned native grassland, 591 ?? 243.1 seeds??m-2 and 784 ?? 334.9 seeds??m-2; burned exotic grassland, 501 ?? 198.9 seeds??m-2 and 196 ?? 123.8 seeds??m-2. Species richness in the seed bank, also averaged over 4 sample dates, was as follows: burned native grassland, 16.3 ?? 1.7 species??m -2 and 19.5 ?? 1.0 species??m-2; burned exotic grassland, 12.0 ?? 3.4 species??m-2 and 11.06 ?? 2.5 species??m-2. The seed bank of burned exotic grassland contained significantly fewer seeds and species than that of burned native grassland. In addition, the seed bank in burned exotic grassland comprised mainly exotic grasses, whereas annual and perennial herbs, most of them native, dominated the seed bank of burned native grassland. Of the 50 species detected in soil samples, only 20 had a persistent seed bank, and only 1 of these was a native perennial bunchgrass. The preponderance of transient species means that eradication of exotic grasses must be followed by reseeding of native grasses and herbs, perhaps repeatedly, if native grassland is to replace exotic grassland.

  7. Novel Quantum States with Exotic Spin Properties - Unconventional Generalization of Magnetism

    DTIC Science & Technology

    2011-12-30

    REPORT Novel quantum states with exotic spin properties- -Unconventional generalization of magnetism 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: My...interference (QPI) spectroscopy of the STM measurement, which is in nice agreement with the 1. REPORT DATE ( DD -MM-YYYY) 4. TITLE AND SUBTITLE 30-12...ANSI Std. Z39.18 - 30-Sep-2011 Novel quantum states with exotic spin properties- -Unconventional generalization of magnetism Report Title ABSTRACT My

  8. Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar.

    PubMed

    Farris, Zach J; Golden, Christopher D; Karpanty, Sarah; Murphy, Asia; Stauffer, Dean; Ratelolahy, Felix; Andrianjakarivelo, Vonjy; Holmes, Christopher M; Kelly, Marcella J

    2015-01-01

    The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore conservation worldwide. Utilizing photographic, line-transect, and habitat sampling, as well as landscape analyses and village-based bushmeat hunting surveys, we provide the first investigation of how multiple forms of habitat degradation (fragmentation, exotic carnivores, human encroachment, and hunting) affect carnivore occupancy across Madagascar's largest protected area: the Masoala-Makira landscape. We found that as degradation increased, native carnivore occupancy and encounter rates decreased while exotic carnivore occupancy and encounter rates increased. Feral cats (Felis species) and domestic dogs (Canis familiaris) had higher occupancy than half of the native carnivore species across Madagascar's largest protected landscape. Bird and small mammal encounter rates were negatively associated with exotic carnivore occupancy, but positively associated with the occupancy of four native carnivore species. Spotted fanaloka (Fossa fossana) occupancy was constrained by the presence of exotic feral cats and exotic small Indian civet (Viverricula indica). Hunting was intense across the four study sites where hunting was studied, with the highest rates for the small Indian civet (mean=90 individuals consumed/year), the ring-tailed vontsira (Galidia elegans) (mean=58 consumed/year), and the fosa (Cryptoprocta ferox) (mean=31 consumed/year). Our modeling results suggest hunters target intact forest where carnivore occupancy, abundance, and species richness, are highest. These various

  9. Anatomy and Disorders of the Oral Cavity of Miscellaneous Exotic Companion Mammals.

    PubMed

    Lennox, Angela M; Miwa, Yasutsugu

    2016-09-01

    Unusual mammalian species such as the hedgehog, sugar glider, and miniature pig are encountered with increasing frequency in exotic companion medicine. Disease of the oral cavity can occur in any species; although occasionally encountered in exotic mammalian species, it is rarely described in the literature. Anatomy and dentition vary significantly; diagnosis and treatment are often extrapolated from that known in other species. The best-documented disease of the oral cavity in this group of species is oral neoplasia in the hedgehog.

  10. Exotic birds increase generalization and compensate for native bird decline in plant-frugivore assemblages.

    PubMed

    García, Daniel; Martínez, Daniel; Stouffer, Daniel B; Tylianakis, Jason M

    2014-11-01

    Exotic species are thought to alter the structure of natural communities and disrupt ecosystem functioning through invasion. Nevertheless, exotic species may also provide ecological insurance when they contribute to maintain ecosystem functions after the decline of native species following anthropogenic disturbance. Here, this hypothesis is tested with the assemblage of frugivorous birds and fleshy-fruited plants of New Zealand, which has suffered strong historical declines in native birds while simultaneously gaining new frugivores introduced by European settlers. We studied the plant-frugivore assemblage from measures of fruit and bird abundances and fruit consumption in nine forest patches, and tested how this changed across a gradient of relative abundance of exotic birds. We then examined how each bird species' role in the assemblage (the proportion of fruits and the number of plant species consumed) varied with their relative abundance, body size and native/exotic status. The more abundant and, to a lesser extent, larger birds species consumed a higher proportion of fruits from more plant species. Exotic birds consumed fruits less selectively and more proportionate to the local availability than did native species. Interaction networks in which exotic birds had a stronger role as frugivores had higher generalization, higher nestedness and higher redundancy of plants. Exotic birds maintained frugivory when native birds became rarer, and diversified the local spectrum of frugivores for co-occurring native plants. These effects seemed related to the fact that species abundances, rather than trait-matching constraints, ultimately determined the patterns of interactions between birds and plants. By altering the structure of plant-frugivore assemblages, exotic birds likely enhance the stability of the community-wide seed dispersal in the face of continued anthropogenic impact.

  11. Native and exotic plants of fragments of sagebrush steppe produced by geomorphic processes versus land use

    USGS Publications Warehouse

    Huntly, N.; Bangert, R.; Hanser, S.E.

    2011-01-01

    Habitat fragmentation and invasion by exotic species are regarded as major threats to the biodiversity of many ecosystems. We surveyed the plant communities of two types of remnant sagebrush-steppe fragments from nearby areas on the Snake River Plain of southeastern Idaho, USA. One type resulted from land use (conversion to dryland agriculture; hereafter AG Islands) and the other from geomorphic processes (Holocene volcanism; hereafter kipukas). We assessed two predictions for the variation in native plant species richness of these fragments, using structural equation models (SEM). First, we predicted that the species richness of native plants would follow the MacArthur-Wilson (M-W) hypothesis of island biogeography, as often is expected for the communities of habitat fragments. Second, we predicted a negative relationship between native and exotic plants, as would be expected if exotic plants are decreasing the diversity of native plants. Finally, we assessed whether exotic species were more strongly associated with the fragments embedded in the agricultural landscape, as would be expected if agriculture had facilitated the introduction and naturalization of non-native species, and whether the communities of the two types of fragments were distinct. Species richness of native plants was not strongly correlated with M-W characteristics for either the AG Islands or the **kipukas. The AG Islands had more species and higher cover of exotics than the kipukas, and exotic plants were good predictors of native plant species richness. Our results support the hypothesis that proximity to agriculture can increase the diversity and abundance of exotic plants in native habitat. In combination with other information, the results also suggest that agriculture and exotic species have caused loss of native diversity and reorganization of the sagebrush-steppe plant community. ?? 2011 Springer Science+Business Media B.V.

  12. etapi and eta'pi spectra and interpretation of possible exotic JPC=1-+ mesons.

    PubMed

    Szczepaniak, Adam P; Swat, Maciej; Dzierba, Alex R; Teige, Scott

    2003-08-29

    We discuss a coupled channel analysis of the etapi and eta'pi systems produced in pi(-)p interactions at 18 GeV/c. We show that known Q(-)Q resonances, together with residual soft meson-meson rescattering, saturate the spectra including the exotic J(PC)=1(-+) channel. The possibility of a narrow exotic resonance at a mass near 1.6 GeV/c(2) cannot, however, be ruled out.

  13. Ultrafast scanning probe microscopy

    DOEpatents

    Weiss, Shimon; Chemla, Daniel S.; Ogletree, D. Frank; Botkin, David

    1995-01-01

    An ultrafast scanning probe microscopy method for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample.

  14. Traversing probe system

    DOEpatents

    Mashburn, Douglas N.; Stevens, Richard H.; Woodall, Harold C.

    1977-01-01

    This invention comprises a rotatable annular probe-positioner which carries at least one radially disposed sensing probe, such as a Pitot tube having a right-angled tip. The positioner can be coaxially and rotatably mounted within a compressor casing or the like and then actuated to orient the sensing probe as required to make measurements at selected stations in the annulus between the positioner and compressor casing. The positioner can be actuated to (a) selectively move the probe along its own axis, (b) adjust the yaw angle of the right-angled probe tip, and (c) revolve the probe about the axis common to the positioner and casing. A cam plate engages a cam-follower portion of the probe and normally rotates with the positioner. The positioner includes a first-motor-driven ring gear which effects slidable movement of the probe by rotating the positioner at a time when an external pneumatic cylinder is actuated to engage the cam plate and hold it stationary. When the pneumatic cylinder is not actuated, this ring gear can be driven to revolve the positioner and thus the probe to a desired circumferential location about the above-mentioned common axis. A second motor-driven ring gear included in the positioner can be driven to rotate the probe about its axis, thus adjusting the yaw angle of the probe tip. The positioner can be used in highly corrosive atmosphere, such as gaseous uranium hexafluoride.

  15. Ultrafast scanning probe microscopy

    DOEpatents

    Weiss, S.; Chemla, D.S.; Ogletree, D.F.; Botkin, D.

    1995-05-16

    An ultrafast scanning probe microscopy method is described for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample. 6 Figs.

  16. Mass and lifetime measurements of exotic nuclei in storage rings.

    PubMed

    Franzke, Bernhard; Geissel, Hans; Münzenberg, Gottfried

    2008-01-01

    Mass and lifetime measurements lead to the discovery and understanding of basic properties of matter. The isotopic nature of the chemical elements, nuclear binding, and the location and strength of nuclear shells are the most outstanding examples leading to the development of the first nuclear models. More recent are the discoveries of new structures of nuclides far from the valley of stability. A new generation of direct mass measurements which allows the exploration of extended areas of the nuclear mass surface with high accuracy has been opened up with the combination of the Experimental Storage Ring ESR and the FRragment Separator FRS at GSI Darmstadt. In-flight separated nuclei are stored in the ring. Their masses are directly determined from the revolution frequency. Dependent on the half-life two complementary methods are applied. Schottky Mass Spectrometry SMS relies on the measurement of the revolution frequency of electron cooled stored ions. The cooling time determines the lower half-life limit to the order of seconds. For Isochronous Mass Spectrometry IMS the ring is operated in an isochronous ion-optical mode. The revolution frequency of the individual ions coasting in the ring is measured using a time-of-flight method. Nuclides with lifetimes down to microseconds become accessible. With SMS masses of several hundreds nuclides have been measured simultaneously with an accuracy in the 2 x 10(-7)-range. This high accuracy and the ability to study large areas of the mass surface are ideal tools to discover new nuclear structure properties and to guide improvements for theoretical mass models. In addition, nuclear half-lives of stored bare and highly charged ions have been measured. This new experimental development is a significant progress since nuclear decay characteristics are mostly known for neutral atoms. For bare and highly charged ions new nuclear decay modes become possible, such as bound-state beta decay. Dramatic changes in the nuclear lifetime

  17. Electrical resistivity probes

    DOEpatents

    Lee, Ki Ha; Becker, Alex; Faybishenko, Boris A.; Solbau, Ray D.

    2003-10-21

    A miniaturized electrical resistivity (ER) probe based on a known current-voltage (I-V) electrode structure, the Wenner array, is designed for local (point) measurement. A pair of voltage measuring electrodes are positioned between a pair of current carrying electrodes. The electrodes are typically about 1 cm long, separated by 1 cm, so the probe is only about 1 inch long. The electrodes are mounted to a rigid tube with electrical wires in the tube and a sand bag may be placed around the electrodes to protect the electrodes. The probes can be positioned in a borehole or on the surface. The electrodes make contact with the surrounding medium. In a dual mode system, individual probes of a plurality of spaced probes can be used to measure local resistance, i.e. point measurements, but the system can select different probes to make interval measurements between probes and between boreholes.

  18. Plant invasions differentially affected by diversity and dominant species in native- and exotic-dominated grasslands.

    PubMed

    Xu, Xia; Polley, H Wayne; Hofmockel, Kirsten; Daneshgar, Pedram P; Wilsey, Brian J

    2015-12-01

    Plant invasions are an increasingly serious global concern, especially as the climate changes. Here, we explored how plant invasions differed between native- and novel exotic-dominated grasslands with experimental addition of summer precipitation in Texas in 2009. Exotic species greened up earlier than natives by an average of 18 days. This was associated with a lower invasion rate early in the growing season compared to native communities. However, invasion rate did not differ significantly between native and exotic communities across all sampling times. The predictors of invasion rate differed between native and exotic communities, with invasion being negatively influenced by species richness in natives and by dominant species in exotics. Interestingly, plant invasions matched the bimodal pattern of precipitation in Temple, Texas, and did not respond to the pulse of precipitation during the summer. Our results suggest that we will need to take different approaches in understanding of invasion between native and exotic grasslands. Moreover, with anticipated increasing variability in precipitation under global climate change, plant invasions may be constrained in their response if the precipitation pulses fall outside the normal growing period of invaders.

  19. Nuclear astrophysics and electron beams

    SciTech Connect

    Schwenk, A.

    2013-11-07

    Electron beams provide important probes and constraints for nuclear astrophysics. This is especially exciting at energies within the regime of chiral effective field theory (EFT), which provides a systematic expansion for nuclear forces and electroweak operators based on quantum chromodynamics. This talk discusses some recent highlights and future directions based on chiral EFT, including nuclear structure and reactions for astrophysics, the neutron skin and constraints for the properties of neutron-rich matter in neutron stars and core-collapse supernovae, and the dark matter response of nuclei.

  20. Spin Modes in Nuclei and Nuclear Forces

    SciTech Connect

    Suzuki, Toshio; Otsuka, Takaharu

    2011-05-06

    Spin modes in stable and unstable exotic nuclei are studied and important roles of tensor and three-body forces on nuclear structure are discussed. New shell model Hamiltonians, which have proper tensor components, are shown to explain shell evolutions toward drip-lines and spin properties of both stable and exotic nuclei, for example, Gamow-Teller transitions in {sup 12}C and {sup 14}C and an anomalous M1 transition in {sup 17}C. The importance and the necessity of the repulsive monopole corrections in isospin T = 1 channel to the microscopic two-body interactions are pointed out. The corrections are shown to lead to the proper shell evolutions in neutron-rich isotopes. The three-body force, in particular the Fujita-Miyazawa force induced by {Delta} excitations, is pointed out to be responsible for the repulsive corrections among the valence neutrons. The important roles of the three-body force on the energies and transitions in exotic oxygen and calcium isotopes are demonstrated.