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Sample records for electron-hole pair creation

  1. Determination of the electron-hole pair creation energy for semiconductors from the spectral responsivity of photodiodes

    CERN Document Server

    Scholze, F; Kuschnerus, P; Rabus, H; Richter, M; Ulm, G

    2000-01-01

    Ionizing radiation can be detected by the measurement of the charge carriers produced in a detector. The improved semiconductor technology now allows detectors operating near the physical limits of the detector materials to be designed. The mean energy required for producing an electron-hole pair, W, is a material property of the semiconductor. Here, the determination of W from the spectral responsivity of photodiodes is demonstrated. Using spectrally dispersed synchrotron radiation, different types of semiconductor photodiodes have been examined in the UV-, VUV-, and soft X-ray spectral range. Their spectral responsivity was determined with relative uncertainties between 0.4% and 1% using a cryogenic electrical-substitution radiometer as primary detector standard. Results are presented for silicon n-on-p junction photodiodes and for GaAsP/Au Schottky diodes at room temperature. The investigations for silicon covered the complete spectral range from 3 to 1500 eV, yielding a constant value W=(3.66+-0.03) eV fo...

  2. Hot carrier-enhanced interlayer electron-hole pair multiplication in 2D semiconductor heterostructure photocells

    Science.gov (United States)

    Barati, Fatemeh; Grossnickle, Max; Su, Shanshan; Lake, Roger K.; Aji, Vivek; Gabor, Nathaniel M.

    2017-12-01

    Strong electronic interactions can result in novel particle-antiparticle (electron-hole, e-h) pair generation effects, which may be exploited to enhance the photoresponse of nanoscale optoelectronic devices. Highly efficient e-h pair multiplication has been demonstrated in several important nanoscale systems, including nanocrystal quantum dots, carbon nanotubes and graphene. The small Fermi velocity and nonlocal nature of the effective dielectric screening in ultrathin layers of transition-metal dichalcogenides (TMDs) indicates that e-h interactions are very strong, so high-efficiency generation of e-h pairs from hot electrons is expected. However, such e-h pair multiplication has not been observed in 2D TMD devices. Here, we report the highly efficient multiplication of interlayer e-h pairs in 2D semiconductor heterostructure photocells. Electronic transport measurements of the interlayer I-VSD characteristics indicate that layer-indirect e-h pairs are generated by hot-electron impact excitation at temperatures near T = 300 K. By exploiting this highly efficient interlayer e-h pair multiplication process, we demonstrate near-infrared optoelectronic devices that exhibit 350% enhancement of the optoelectronic responsivity at microwatt power levels. Our findings, which demonstrate efficient carrier multiplication in TMD-based optoelectronic devices, make 2D semiconductor heterostructures viable for a new class of ultra-efficient photodetectors based on layer-indirect e-h excitations.

  3. Hot carrier-enhanced interlayer electron-hole pair multiplication in 2D semiconductor heterostructure photocells.

    Science.gov (United States)

    Barati, Fatemeh; Grossnickle, Max; Su, Shanshan; Lake, Roger K; Aji, Vivek; Gabor, Nathaniel M

    2017-12-01

    Strong electronic interactions can result in novel particle-antiparticle (electron-hole, e-h) pair generation effects, which may be exploited to enhance the photoresponse of nanoscale optoelectronic devices. Highly efficient e-h pair multiplication has been demonstrated in several important nanoscale systems, including nanocrystal quantum dots, carbon nanotubes and graphene. The small Fermi velocity and nonlocal nature of the effective dielectric screening in ultrathin layers of transition-metal dichalcogenides (TMDs) indicates that e-h interactions are very strong, so high-efficiency generation of e-h pairs from hot electrons is expected. However, such e-h pair multiplication has not been observed in 2D TMD devices. Here, we report the highly efficient multiplication of interlayer e-h pairs in 2D semiconductor heterostructure photocells. Electronic transport measurements of the interlayer I-V SD characteristics indicate that layer-indirect e-h pairs are generated by hot-electron impact excitation at temperatures near T = 300 K. By exploiting this highly efficient interlayer e-h pair multiplication process, we demonstrate near-infrared optoelectronic devices that exhibit 350% enhancement of the optoelectronic responsivity at microwatt power levels. Our findings, which demonstrate efficient carrier multiplication in TMD-based optoelectronic devices, make 2D semiconductor heterostructures viable for a new class of ultra-efficient photodetectors based on layer-indirect e-h excitations.

  4. Coherent Interaction of Three-Dimensionally Confined Electron-Hole Pairs with LO-Phonons

    DEFF Research Database (Denmark)

    Gindele, F.; Reimann, T.; Woggon, U.

    1997-01-01

    The spectrally resolved FWM signal of CdSe quantum dots with sizes below the bulk excitonic Bohr radius has been studied as a function of temperature and excitation intensity and compared with bulk CdSe. A clear oscillation with a period of 163fs (approximate to 25 meV) is found in the transient...... FWM signal and attributed to a coherent coupling of confined electron-hole pairs with LO-phonons. Two side bands are observed in the spectrum 25 meV below and above the excitonic resonance. The strong coupling to LO-phonons is observed even at excitation densities around 1 x 10(16) cm(-3) which...

  5. Optical emission of graphene and electron-hole pair production induced by a strong terahertz field

    Science.gov (United States)

    Oladyshkin, I. V.; Bodrov, S. B.; Sergeev, Yu. A.; Korytin, A. I.; Tokman, M. D.; Stepanov, A. N.

    2017-10-01

    We report on experimental observation of optical emission of graphene induced by an intense terahertz (THz) pulse. P-doped chemical-vapor-deposition graphene with an initial Fermi energy of about 200 meV was used; optical photons were detected in the 2.0-3.5 eV range. Emission started when the THz field amplitude exceeded 100 kV/cm. For the THz fields from 200 to 300 kV/cm, the temperature of optical radiation was constant, while the number of emitted photons increased by several dozen times. This fact clearly indicates multiplication of electron-hole pairs induced by an external field and not electron heating. The experimental data are in good agreement with the theory of Landau-Zener interband transitions. It is shown theoretically that Landau-Zener transitions are possible even in the case of heavily doped graphene because the strong THz field removes quasiparticles from the region of interband transitions for several femtoseconds, which cancels the Pauli blocking effect.

  6. Electron pair creation by photons

    NARCIS (Netherlands)

    Holtwijk, Theodoor

    1960-01-01

    In our experiment on the creation of electron pairs a 5 MeV betatron was used as radiation source and a cloud chamber (with magnetic field) was used as detection instrument. The experimental arrangement is described in section 2.1. The cloud chamber was of the overcompression type so that the

  7. Energy Dissipation during Diffusion at Metal Surfaces: Disentangling the Role of Phonons versus Electron-Hole Pairs

    Science.gov (United States)

    Rittmeyer, Simon P.; Ward, David J.; Gütlein, Patrick; Ellis, John; Allison, William; Reuter, Karsten

    2016-11-01

    Helium spin echo experiments combined with ab initio based Langevin molecular dynamics simulations are used to quantify the adsorbate-substrate coupling during the thermal diffusion of Na atoms on Cu(111). An analysis of trajectories within the local density friction approximation allows the contribution from electron-hole pair excitations to be separated from the total energy dissipation. Despite the minimal electronic friction coefficient of Na and the relatively small mass mismatch to Cu promoting efficient phononic dissipation, about (20 ±5 )% of the total energy loss is attributable to electronic friction. The results suggest a significant role of electronic nonadiabaticity in the rapid thermalization generally relied upon in adiabatic diffusion theories.

  8. Long-range coupling of electron-hole pairs in spatially separated organic donor-acceptor layers

    Science.gov (United States)

    Nakanotani, Hajime; Furukawa, Taro; Morimoto, Kei; Adachi, Chihaya

    2016-01-01

    Understanding exciton behavior in organic semiconductor molecules is crucial for the development of organic semiconductor-based excitonic devices such as organic light-emitting diodes and organic solar cells, and the tightly bound electron-hole pair forming an exciton is normally assumed to be localized on an organic semiconducting molecule. We report the observation of long-range coupling of electron-hole pairs in spatially separated electron-donating and electron-accepting molecules across a 10-nanometers-thick spacer layer. We found that the exciton energy can be tuned over 100 megaelectron volts and the fraction of delayed fluorescence can be increased by adjusting the spacer-layer thickness. Furthermore, increasing the spacer-layer thickness produced an organic light-emitting diode with an electroluminescence efficiency nearly eight times higher than that of a device without a spacer layer. Our results demonstrate the first example of a long-range coupled charge-transfer state between electron-donating and electron-accepting molecules in a working device. PMID:26933691

  9. Dirac electron-hole pairing gap in the heterostructure of ultra-thin films of topological insulator bilayer

    Science.gov (United States)

    Wang, Zhigang; Fu, Zhen-Guo; Zhang, Ping

    2015-06-01

    The electron-hole pairing gap in a system of topological insulator (TI) ultra-thin film bilayer separated by a dielectric barrier is theoretically investigated beyond the mean-field approximation. We show that the pairing gap Δ is dramatically suppressed when accounting for the Coulomb correlation effect as well as the finite-thickness effect of the dielectric barrier. However, Δ can be increased by the coupling between the upper and lower surface states of each TI ultra-thin film. In order to observe much larger Δ in the present structure experimentally, the dielectric surrounding media materials with much lower dielectric constant, such as SiO2-based xerogel films, may be needed.

  10. Multi-pair states in electron–positron pair creation

    Directory of Open Access Journals (Sweden)

    Anton Wöllert

    2016-09-01

    Full Text Available Ultra strong electromagnetic fields can lead to spontaneous creation of single or multiple electron–positron pairs. A quantum field theoretical treatment of the pair creation process combined with numerical methods provides a description of the fermionic quantum field state, from which all observables of the multiple electron–positron pairs can be inferred. This allows to study the complex multi-particle dynamics of electron–positron pair creation in-depth, including multi-pair statistics as well as momentum distributions and spin. To illustrate the potential benefit of this approach, it is applied to the intermediate regime of pair creation between nonperturbative Schwinger pair creation and perturbative multiphoton pair creation where the creation of multi-pair states becomes nonnegligible but cascades do not yet set in. Furthermore, it is demonstrated how spin and helicity of the created electrons and positrons are affected by the polarization of the counterpropagating laser fields, which induce the creation of electron–positron pairs.

  11. Pair creation and plasma oscillations.

    Energy Technology Data Exchange (ETDEWEB)

    Prozorkevich, A. V.; Vinnik, D. V.; Schmidt, S. M.; Hecht, M. B.; Roberts, C. D.

    2000-12-15

    We describe aspects of particle creation in strong fields using a quantum kinetic equation with a relaxation-time approximation to the collision term. The strong electric background field is determined by solving Maxwell's equation in tandem with the Vlasov equation. Plasma oscillations appear as a result of feedback between the background field and the field generated by the particles produced. The plasma frequency depends on the strength of the initial background fields and the collision frequency, and is sensitive to the necessary momentum-dependence of dressed-parton masses.

  12. Numerical studies of pair creation in counterpropagating laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Ruf, Matthias

    2009-05-27

    Pair creation from vacuum induced by electromagnetic fields is probably one of the most intriguing phenomena in physics. If the fields are sufficiently strong, the QED vacuum become unstable. Due to the remarkable progress in laser technology during recent years an experimental investigation of pair creation by pure laser light is coming into reach. The focus of this thesis is on pair creation in counterpropagating laser beams. The pair creation probability is calculated employing the numerically obtained solutions of the Dirac equation. This numerical ansatz has the capability of calculating the momentum distribution of the created pairs in a single propagation, for pure time dependent field configurations. Furthermore, it allows to take the magnetic component of the laser fields into account, which is usually neglected. The latter strongly affects the creation process at high laser frequency. The involved numerical calculations are rather time consuming, therefore the second project of this thesis was to develop a highly efficient code for solving relativistic quantum mechanical problems. This is accomplished by adopting the split-operator method to the Klein-Gordon equation. Here the possibility arises to use parallel computing. However the corresponding spin-statistics becomes crucial in the case of pair creation, demonstrated in several examples. (orig.)

  13. Pair creation constrains superluminal neutrino propagation.

    Science.gov (United States)

    Cohen, Andrew G; Glashow, Sheldon L

    2011-10-28

    The OPERA collaboration claims that muon neutrinos with a mean energy of 17.5 GeV travel 730 km from CERN to the Gran Sasso at a speed exceeding that of light by about 7.5 km/s or 25 ppm. However, we show that superluminal neutrinos may lose energy rapidly via the bremsstrahlung of electron-positron pairs (ν → ν + e- + e+). For the claimed superluminal velocity and at the stated mean energy, we find that most of the neutrinos would have suffered several pair emissions en route, causing the beam to be depleted of higher energy neutrinos. This presents a significant challenge to the superluminal interpretation of the OPERA data. Furthermore, we appeal to Super-Kamiokande and IceCube data to establish strong new limits on the superluminal propagation of high-energy neutrinos.

  14. Ab initio molecular dynamics study of the Eley-Rideal reaction of H + Cl-Au(111) → HCl + Au(111): Impact of energy dissipation to surface phonons and electron-hole pairs.

    Science.gov (United States)

    Zhou, Linsen; Zhou, Xueyao; Alducin, Maite; Zhang, Liang; Jiang, Bin; Guo, Hua

    2018-01-07

    The reaction between an impinging H atom and a Cl atom adsorbed on Au(111), which is a prototype for the Eley-Rideal mechanism, is investigated using ab initio molecular dynamics at different incidence angles. The reaction yielding gaseous HCl with large internal excitation proceeds via both direct and hot-atom mechanisms. Significant energy exchange with both surface phonons and electron-hole pairs has been observed. However, their impact on the reactivity and final state distributions was found to be limited, thanks to the large exothermicity and small barrier of the reaction.

  15. Pair Creation and Evolution of Black Holes During Inflation

    OpenAIRE

    Bousso, Raphael; Hawking, Stephen W.

    1996-01-01

    We summarise recent work on the quantum production of black holes in the inflationary era. We describe, in simple terms, the Euclidean approach used, and the results obtained both for the pair creation rate and for the evolution of the black holes.

  16. Pair creation supernovae at low and high redshift

    NARCIS (Netherlands)

    Langer, N.|info:eu-repo/dai/nl/304829498; Norman, C.A.; de Koter, A.; Vink, J.|info:eu-repo/dai/nl/182880559; Cantiello, M.|info:eu-repo/dai/nl/304840866; Yoon, S.C.|info:eu-repo/dai/nl/266576753

    2007-01-01

    Aims:Pair creation supernovae (PCSN) are thought to be produced from very massive low metallicity stars. The spectacularly bright SN 2006gy does show several signatures expected from PCSNe. Here, we investigate the metallicity threshold below which PCSN can form and estimate their occurrence rate.

  17. Pair creation supernovae at low and high redshift

    NARCIS (Netherlands)

    Langer, N.; Norman, C.A.; de Koter, A.; Vink, J.S.; Cantiello, M.; Yoon, S.C.

    2007-01-01

    Aims.Pair creation supernovae (PCSN) are thought to be produced from very massive low metallicity stars. The spectacularly bright SN 2006gy does show several signatures expected from PCSNe. Here, we investigate the metallicity threshold below which PCSN can form and estimate their occurrence rate.

  18. Magnetic pair creation transparency in gamma-ray pulsars

    Energy Technology Data Exchange (ETDEWEB)

    Story, Sarah A.; Baring, Matthew G., E-mail: ss16@rice.edu, E-mail: baring@rice.edu [Department of Physics and Astronomy, MS 108, Rice University, Houston, TX 77251 (United States)

    2014-07-20

    Magnetic pair creation, γ → e {sup +} e {sup –}, has been at the core of radio pulsar paradigms and central to polar cap models of gamma-ray pulsars for over three decades. The Fermi gamma-ray pulsar population now exceeds 140 sources and has defined an important part of Fermi's science legacy, providing rich information for the interpretation of young energetic pulsars and old millisecond pulsars. Among the population characteristics well established is the common occurrence of exponential turnovers in their spectra in the 1-10 GeV range. These turnovers are too gradual to arise from magnetic pair creation in the strong magnetic fields of pulsar inner magnetospheres. By demanding insignificant photon attenuation precipitated by such single-photon pair creation, the energies of these turnovers for Fermi pulsars can be used to compute lower bounds for the typical altitude of GeV band emission. This paper explores such pair transparency constraints below the turnover energy and updates earlier altitude bound determinations that have been deployed in various Fermi pulsar papers. For low altitude emission locales, general relativistic influences are found to be important, increasing cumulative opacity, shortening the photon attenuation lengths, and also reducing the maximum energy that permits escape of photons from a neutron star magnetosphere. Rotational aberration influences are also explored, and are found to be small at low altitudes, except near the magnetic pole. The analysis presented in this paper clearly demonstrates that including near-threshold physics in the pair creation rate is essential to deriving accurate attenuation lengths and escape energies. The altitude bounds are typically in the range of 2-7 stellar radii for the young Fermi pulsar population, and provide key information on the emission altitude in radio quiet pulsars that do not possess double-peaked pulse profiles. The bound for the Crab pulsar is at a much higher altitude, with the

  19. Observation of Anomalous Internal Pair Creation in $^8$Be

    CERN Document Server

    Krasznahorkay, A J; Csige, L; Gácsi, Z; Gulyás, J; Hunyadi, M; Ketel, T J; Krasznahorkay, A; Kuti, I; Nyakó, B M; Stuhl, L; Timár, J; Tornyi, T G; Vajta, Zs

    2015-01-01

    The electron–positron angular correlation was measured for the isoscalar magnetic dipole 18.15 MeV transition in 8Be. Significant, peak-like deviation was observed from the internal pair creation at Θ ≈ 140° in the angular correlation. This observation might indicate that in an intermediate step a neutral isoscalar particle with a mass of 16.70 ± 0.35 (stat.)±0.5(sys.) MeV∕c2 and Jπ = 1+ was created.

  20. Density variation in the electron-hole liquid in stressed germanium and silicon

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, S.M.

    1979-08-01

    A detailed study is presented of the variation in electron-hole pair density in the electron-hole liquid (EHL) in stressed Ge and Si. First, the variation of the density and other properties of the EHL is studied theoretically as a function of uniaxial stress in both Ge and Si. Second, the variation of the density with position is studied both theoretically and experimentally in the strain-confined electron-hole liquid (SCEHL) in Ge.

  1. Gauge gravity in noncommutative de Sitter space and pair creation

    Energy Technology Data Exchange (ETDEWEB)

    Mebarki, N; Khodja, L; Aisaoui, H [Laboratoire de Physique Mathematique et Subatomique, Faculte des Sciences, Mentouri University, Constantine (Algeria); Zaim, S [Departement de Physique, Faculte des Sciences, Universite Hadj Lakhdar, Batna (Algeria)], E-mail: zaimslimane@yahoo.fr

    2008-10-15

    From the invariance of the generalized space-time non-commutative commutation relations, local Poincare and general coordinate transformations are derived. Moreover, a generalized Dirac equation is obtained. Applied to the de Sitter universe, it is shown that the space-time non-commutativity contributes to the particle creation process and induces a Casimir-like effect.

  2. Acoustic absorption by the electron-hole liquid in germanium

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, A.D.A.

    1977-11-01

    The absorption of ultrasonic acoustic waves by the electron-hole liquid that may be created in germanium at liquid helium temperatures by intense optical excitation was studied. This is a degenerate compensated Fermi liquid that exhibits the behavior of both classical dynamics in a force field, and quantum phenomena in a magnetic field. Results of theoretical and experimental studies of the interaction of the mobile liquid with a travelling acoustic wave force field, the attenuation of the wave due to energy-dissipative processes coupling the liquid to the crystal lattice, and the effect of a moderately strong magnetic field on the dynamic behavior of the system are presented. In unstrained germanium the electron-hole liquid (EHL) is known to be condensed into small droplets of radius approx. 5 ..mu..m; the creation of an EHL energy well by the application of an inhomogeneous stress causes the liquid to be aggregated into a macroscopically large volume.

  3. Progress toward the creation of magnetically confined pair plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, Haruhiko [Max-Planck-Institut fuer Plasmaphysik (Germany); The University of Tokyo (Japan); Hergenhahn, Uwe; Paschkowski, Norbert; Stanja, Juliane; Stenson, Eve V. [Max-Planck-Institut fuer Plasmaphysik (Germany); Niemann, Holger; Sunn Pedersen, Thomas [Max-Planck-Institut fuer Plasmaphysik (Germany); Ernst-Moritz-Arndt-Universitaet Greifswald (Germany); Stoneking, Matthew R. [Max-Planck-Institut fuer Plasmaphysik (Germany); Lawrence University (United States); Hugenschmidt, Christoph; Piochacz, Christian; Vohburger, Sebastian [Technische Universitaet Muenchen (Germany); Schweikhard, Lutz [Ernst-Moritz-Arndt-Universitaet Greifswald (Germany); Danielson, James R.; Surko, Clifford M. [University of California, San Diego (United States)

    2016-07-01

    The PAX (Positron Accumulation eXperiment) and APEX (A Positron Electron eXperiment) projects aim to experimentally study the unique wave propagation and stability properties of pair plasmas. We plan to accumulate a large number of positrons in a multicell-type trap system (PAX) and to confine them with electrons in APEX, a levitated dipole or stellarator configuration, operated at the NEPOMUC facility, the world's most intense positron source. In this contribution, we report on recent results from PAX and APEX. We have conducted electron experiments with a 2.3 T Penning-Malmberg trap; confinement for more than 1 hour and observation of a collective mode were demonstrated. At NEPOMUC, we have characterized the positron beam for a wide energy range. In a prototype permanent-magnet dipole trap, efficient (38%) injection of the remoderated 5 eV positron beam was realized using E x B drifts. Based on these results, design studies on the confinement of pair-plasmas in a levitated dipole trap are ongoing.

  4. Experimental study of single-vertex $(e^{-}-e^{+})$ pair creation in a crystal

    CERN Multimedia

    2002-01-01

    This experiment will study the newly predicted process of $e^{-}-e^{+}$ pair production by high energy photons incident along major axial direction of a single crystal. This process is based upon the well-known channeling properties of negatively charged particles along atomic rows of a crystal. The $e^{-}-e^{+}$ pair creation may proceed in a one-step process, without violating energy and momentum conversation laws, due to the lowering of the total energy of the channeled electron (Fig. 1). \\\\ \\\\ The pair creation rate should increase with increasing photon energies (above a threshold of a few GeV) and largely exceed the Bethe-Heitler process rate for photon energies of a few tens of GeV. It is also expected that the created particles share the photon energy nearly equally, in contrast with the rather flat energy distribution associated with the Bethe-Heitler process. \\\\ \\\\ The experimental set-up (Fig. 2) is designed for the study of those two features: photon energy dependence of the pair creation rate, an...

  5. Ultra-Intense Short-Pulse Pair Creation Using the Texas Petawatt Laser

    Science.gov (United States)

    Liang, Edison; Henderson, Alexander; Clarke, Taylor; Taylor, Devin; Chaguine, Petr; Serratto, Kristina; Riley, Nathan; Dyer, Gilliss; Donovan, Michael; Ditmire, Todd

    2013-10-01

    We report results from the 2012 pair creation experiment using the Texas Petawatt Laser. Up to 1011 positrons per steradian were detected using 100 Joule pulses from the Texas Petawatt Laser to irradiate gold targets, with peak laser intensities up to 1.9 × 1021W/cm2 and pulse durations as short as 130 fs. Positron-to-electron ratios exceeding 20% were measured on some shots. The positron energy, positron yield per unit laser energy, and inferred positron density are significantly higher than those reported in previous experiments. This confirms that, for a given laser energy, higher intensity and shorter pulses irradiating thicker targets are more favorable for pair creation. Narrow-band high-energy positrons up to 23 MeV were observed from thin targets. Supported by DOE Grant DE-SC-0001481 and Rice FIF.

  6. Skyrmion-Anti-Skyrmion Pair Creation by in-Plane Currents.

    Science.gov (United States)

    Stier, Martin; Häusler, Wolfgang; Posske, Thore; Gurski, Gregor; Thorwart, Michael

    2017-06-30

    Magnetic Skyrmions can be considered as localized vortexlike spin textures which are topologically protected in continuous systems. Because of their stability, their small size, and the possibility to move them by low electric currents, they are promising candidates for spintronic devices. Without changing the topological charge, it is possible to create Skyrmion-anti-Skyrmion pairs. We derive a Skyrmion equation of motion which reveals how spin-polarized charge currents create Skyrmion-anti-Skyrmion pairs. It allows us to identify general prerequisites for the pair creation process. We corroborate these general principles by numerical simulations. On a lattice, where the concept of topological protection has to be replaced by that of a finite energy barrier, the anti-Skyrmion partner of the pairs is annihilated and only the Skyrmion survives. This eventually changes the total Skyrmion number and yields a new way of creating and controlling Skyrmions.

  7. Analysis and simulation of BGK electron holes

    Directory of Open Access Journals (Sweden)

    L. Muschietti

    1999-01-01

    Full Text Available Recent observations from satellites crossing regions of magnetic-field-aligned electron streams reveal solitary potential structures that move at speeds much greater than the ion acoustic/thermal velocity. The structures appear as positive potential pulses rapidly drifting along the magnetic field, and are electrostatic in their rest frame. We interpret them as BGK electron holes supported by a drifting population of trapped electrons. Using Laplace transforms, we analyse the behavior of one phase-space electron hole. The resulting potential shapes and electron distribution functions are self-consistent and compatible with the field and particle data associated with the observed pulses. In particular, the spatial width increases with increasing amplitude. The stability of the analytic solution is tested by means of a two-dimensional particle-in-cell simulation code with open boundaries. We consider a strongly magnetized parameter regime in which the bounce frequency of the trapped electrons is much less than their gyrofrequency. Our investigation includes the influence of the ions, which in the frame of the hole appear as an incident beam, and impinge on the BGK potential with considerable energy. The nonlinear structure is remarkably resilient

  8. Multiloop Euler-Heisenberg Lagrangians, Schwinger Pair Creation, and the Photon S-Matrix

    Science.gov (United States)

    Huet, I.; de Traubenberg, M. R.; Schubert, C.

    2017-03-01

    Although the perturbation series in quantum electrodynamics has been studied for eighty years concerning its high-order behavior, our present understanding is still poorer than for many other field theories. An interesting case is Schwinger pair creation in a constant electric field, which may possibly provide a window to high loop orders; simple non-perturbative closed-form expressions have been conjectured for the pair creation rate in the weak field limit, for scalar QED in 1982 by Affleck, Alvarez, and Manton, and for spinor QED by Lebedev and Ritus in 1984. Using Borel analysis, these can be used to obtain non-perturbative information on the on-shell renormalized N-photon amplitudes at large N and low energy. This line of reasoning also leads to a number of nontrivial predictions for the effective QED Lagrangian in either four or two dimensions at any loop order, and preliminary results of a calculation of the three-loop Euler-Heisenberg Lagrangian in two dimensions are presented.

  9. Plasma electron-hole kinematics: momentum conservation

    CERN Document Server

    Hutchinson, I H

    2016-01-01

    We analyse the kinematic properties of a plasma electron hole: a non-linear self-sustained localized positive electric potential perturbation, trapping electrons, that behaves as a coherent entity. When a hole accelerates or grows in depth, ion and electron plasma momentum is changed both within the hole and outside it, by an energization process we call jetting. We present a comprehensive analytic calculation of the momentum changes of an isolated general one-dimensional hole. The conservation of the total momentum gives the hole's kinematics, determining its velocity evolution. Our results explain many features of the behavior of hole speed observed in numerical simulations, including self-acceleration at formation, and hole pushing and trapping by ion streams.

  10. Plasma electron hole oscillatory velocity instability

    Science.gov (United States)

    Zhou, Chuteng; Hutchinson, Ian H.

    2017-10-01

    In this paper, we report a new type of instability of electron holes (EHs) interacting with passing ions. The nonlinear interaction of EHs and ions is investigated using a new theory of hole kinematics. It is shown that the oscillation in the velocity of the EH parallel to the magnetic field direction becomes unstable when the hole velocity in the ion frame is slower than a few times the cold ion sound speed. This instability leads to the emission of ion-acoustic waves from the solitary hole and decay in its magnitude. The instability mechanism can drive significant perturbations in the ion density. The instability threshold, oscillation frequency and instability growth rate derived from the theory yield quantitative agreement with the observations from a novel high-fidelity hole-tracking particle-in-cell code.

  11. Pair creation of extremal black holes and Kaluza-Klein monopoles

    Energy Technology Data Exchange (ETDEWEB)

    Dowker, F.; Gauntlett, J.P.; Giddings, S.B.; Horowitz, G.T. (Department of Physics, University of California, Santa Barbara, California 93106 (United States) Enrico Fermi Institute, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637 (United States))

    1994-08-15

    Classical solutions describing charged dilaton black holes accelerating in a background magnetic field have recently been found. They include the Ernst metric of the Einstein-Maxwell theory as a special case. We study the extremal limit of these solutions in detail, both at the classical and quantum levels. It is shown that near the event horizon the extremal solutions reduce precisely to the static extremal black hole solutions. For a particular value of the dilaton coupling, these extremal black holes are five-dimensional Kaluza-Klein monopoles. The Euclidean sections of these solutions can be interpreted as instantons describing the pair creation of extremal black holes and/or Kaluza-Klein monopoles in a magnetic field. The action of these instantons is calculated and found to agree with the Schwinger result in the weak-field limit. For the Euclidean Ernst solution, the action for the extremal solution differs from that of the previously discussed wormhole instanton by the Bekenstein-Hawking entropy. However, in many cases quantum corrections become large in the vicinity of the black hole, and the precise description of the creation process is unknown.

  12. Natural versus artificial creation of base pairs in DNA: origin of nucleobases from the perspectives of unnatural base pair studies.

    Science.gov (United States)

    Hirao, Ichiro; Kimoto, Michiko; Yamashige, Rie

    2012-12-18

    Since life began on Earth, the four types of bases (A, G, C, and T(U)) that form two sets of base pairs have remained unchanged as the components of nucleic acids that replicate and transfer genetic information. Throughout evolution, except for the U to T modification, the four base structures have not changed. This constancy within the genetic code raises the question of how these complicated nucleotides were generated from the molecules in a primordial soup on the early Earth. At some prebiotic stage, the complementarity of base pairs might have accelerated the generation and accumulation of nucleotides or oligonucleotides. We have no clues whether one pair of nucleobases initially appeared on the early Earth during this process or a set of two base pairs appeared simultaneously. Recently, researchers have developed new artificial pairs of nucleobases (unnatural base pairs) that function alongside the natural base pairs. Some unnatural base pairs in duplex DNA can be efficiently and faithfully amplified in a polymerase chain reaction (PCR) using thermostable DNA polymerases. The addition of unnatural base pair systems could expand the genetic alphabet of DNA, thus providing a new mechanism for the generation novel biopolymers by the site-specific incorporation of functional components into nucleic acids and proteins. Furthermore, the process of unnatural base pair development might provide clues to the origin of the natural base pairs in a primordial soup on the early Earth. In this Account, we describe the development of three representative types of unnatural base pairs that function as a third pair of nucleobases in PCR and reconsider the origin of the natural nucleic acids. As researchers developing unnatural base pairs, they use repeated "proof of concept" experiments. As researchers design new base pairs, they improve the structures that function in PCR and eliminate those that do not. We expect that this process is similar to the one functioning in the

  13. Plasma phase transition in hydrogen and electron-hole plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Filinov, V.; Levashov, P.; Fortov, V. [Institute for High Energy Density, Russian Academy of Sciences, Izhorskay 13/19, Moscow 127412 (Russian Federation); Bonitz, M. [Fachbereich Physik, Universitaet Rostock, D-18051 Rostock (Germany); Ebeling, W. [Institut fuer Physik, Humboldt-Universitaet Berlin Invalidenstrasse 110, D-10115 Berlin (Germany); Schlanges, M. [Fachbereich Physik, Universitaet Greifswald, D-17489 Greifswald (Germany)

    2003-10-01

    The plasma phase transition in dense hydrogen and in electron-hole plasmas is investigated by direct path integral Monte Carlo simulations. Hydrogen results for the internal energy at T=10,000 K show a deep minimum and strong fluctuations around the density n=10{sup 23} cm{sup -3} indicating the existence of a phase transition. To verify this explanation, the analogous phenomenon is studied for an electron-hole plasma in Germanium. The calculated phase boundary of the electron-hole liquid is found to agree reasonably well with the available experimental data. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Observation of image pair creation and annihilation from superluminal scattering sources.

    Science.gov (United States)

    Clerici, Matteo; Spalding, Gabriel C; Warburton, Ryan; Lyons, Ashley; Aniculaesei, Constantin; Richards, Joseph M; Leach, Jonathan; Henderson, Robert; Faccio, Daniele

    2016-04-01

    The invariance of the speed of light is one of the foundational pillars of our current understanding of the universe. It implies a series of consequences related to our perception of simultaneity and, ultimately, of time itself. Whereas these consequences are experimentally well studied in the case of subluminal motion, the kinematics of superluminal motion lack direct evidence or even a clear experimental approach. We investigate kinematic effects associated with the superluminal motion of a light source. By using high-temporal-resolution imaging techniques, we directly demonstrate that if the source approaches an observer at superluminal speeds, the temporal ordering of events is inverted and its image appears to propagate backward. Moreover, for a source changing its speed and crossing the interface between subluminal and superluminal propagation regions, we observe image pair annihilation and creation, depending on the crossing direction. These results are very general and show that, regardless of the emitter speed, it is not possible to unambiguously determine the kinematics of an event from imaging and time-resolved measurements alone. This has implications not only for light, but also, for example, for sound and other wave phenomena.

  15. Strain-confined electron-hole liquid in Ge: Density variations and compressibility

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, S.M.

    1982-07-15

    We present a detailed theoretical and experimental investigation of a spatial variation in the electron-hole--pair density in the strain-confined electron-hole liquid in Ge. The density variation can be dramatic: We observed a compression of the central density by a factor of 3 for our largest drop radius, Rroughly-equal0.7 mm. Our experimental density profiles, obtained using Abel transforms of spatial luminescence profiles, are in good agreement with the theoretical predictions of approximately parabolic profiles with densities larger than the equilibrium value at the center of the drop. Our previous first-order theory has been extended to include the full density dependence of the pair free energy at finite stress and temperature. We discuss the shape and power dependence of spatial luminescence profiles and luminescence spectra, since the spatial density variation increases with drop size. We use the central densities for drop sizes ranging over an order of magnitude to measure the density dependence of the electron-hole--liquid chemical potential, providing a sensitive test of many-body theories for the correlation energy. We obtain an improved value for the isothermal compressibility of the strain-confined liquid: K/sub T/ = 0.067 +- 0.017 cm/sup 2//dyn for n = 0.47 x 10/sup 17/ cm/sup -3/, T = 1.9 K, and -sigma = 5.5 kgf/mm/sup 2/, where kgf represents kilogram force.

  16. The impact of long-range electron-hole interaction on the charge separation yield of molecular photocells

    Science.gov (United States)

    Nemati Aram, Tahereh; Ernzerhof, Matthias; Asgari, Asghar; Mayou, Didier

    2017-01-01

    We discuss the effects of charge carrier interaction and recombination on the operation of molecular photocells. Molecular photocells are devices where the energy conversion process takes place in a single molecular donor-acceptor complex attached to electrodes. Our investigation is based on the quantum scattering theory, in particular on the Lippmann-Schwinger equation; this minimizes the complexity of the problem while providing useful and non-trivial insight into the mechanism governing photocell operation. In this study, both exciton pair creation and dissociation are treated in the energy domain, and therefore there is access to detailed spectral information, which can be used as a framework to interpret the charge separation yield. We demonstrate that the charge carrier separation is a complex process that is affected by different parameters, such as the strength of the electron-hole interaction and the non-radiative recombination rate. Our analysis helps to optimize the charge separation process and the energy transfer in organic solar cells and in molecular photocells.

  17. Calculation of properties of the electron-hole liquid in uniaxially stressed Ge and Si

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, S.M.

    1982-06-15

    We present a detailed theoretical study of the stress dependence of properties of the electron-hole liquid, both at zero and finite temperatures, in <111>-stressed Ge and <100>-stressed Si. These properties include the ground-state equilibrium density, pair energy, electron and hole Fermi energies, sign of the electron-hole drop charge, luminescence linewidth, and liquid compressibility. The results are compared at T = 0 to the calculations of Kirczenow and Singwi and at Troughly-equal2 K to the available data. We discuss the possibility of a phase transition associated with the depopulation of the upper electron valleys in Ge. We also discuss methods of extrapolating from finite to infinite stress. The importance of the nonparabolicity of the valence bands is emphasized throughout. We discuss ranges of validity for a low-temperature expansion of the free energy. Results are presented for the systematic low-temperature variation of the liquid density, Fermi energy, and chemical potential and for the critical temperature and density. These theoretical results are found to be in reasonably good agreement with available data. Finally, we discuss scaling relations for combinations of electron-hole--liquid properties.

  18. Dynamical Birefringence: Electron-Hole Recollisions as Probes of Berry Curvature

    Directory of Open Access Journals (Sweden)

    Hunter B. Banks

    2017-11-01

    Full Text Available The direct measurement of Berry phases is still a great challenge in condensed-matter systems. The bottleneck has been the ability to adiabatically drive an electron coherently across a large portion of the Brillouin zone in a solid where the scattering is strong and complicated. We break through this bottleneck and show that high-order sideband generation (HSG in semiconductors is intimately affected by Berry phases. Electron-hole recollisions and HSG occur when a near-band-gap laser beam excites a semiconductor that is driven by sufficiently strong terahertz-frequency electric fields. We carry out experimental and theoretical studies of HSG from three GaAs/AlGaAs quantum wells. The observed HSG spectra contain sidebands up to the 90th order, to our knowledge the highest-order optical nonlinearity reported in solids. The highest-order sidebands are associated with electron-hole pairs driven coherently across roughly 10% of the Brillouin zone around the Γ point. The principal experimental claim is a dynamical birefringence: the intensity and polarization of the sidebands depend on the relative polarization of the exciting near-infrared (NIR and the THz electric fields, as well as on the relative orientation of the laser fields with the crystal. We explain dynamical birefringence by generalizing the three-step model for high-order harmonic generation. The hole accumulates Berry phases due to variation of its internal state as the quasimomentum changes under the THz field. Dynamical birefringence arises from quantum interference between time-reversed pairs of electron-hole recollision pathways. We propose a method to use dynamical birefringence to measure Berry curvature in solids.

  19. Pair creation in collision of γ-ray beams produced with high-intensity lasers.

    Science.gov (United States)

    Ribeyre, X; d'Humières, E; Jansen, O; Jequier, S; Tikhonchuk, V T; Lobet, M

    2016-01-01

    Direct production of electron-positron pairs in two-photon collisions, the Breit-Wheeler process, is one of the basic processes in the universe. However, it has never been directly observed in the laboratory because of the absence of the intense γ-ray sources. Laser-induced synchrotron sources emission may open a way to observe this process. The feasibility of an experimental setup using a MeV photon source is studied in this paper. We compare several γ-ray sources and estimate the expected number of electron-positron pairs and competing processes by using numerical simulations including quantum electrodynamic effects.

  20. Multi-photon creation and single-photon annihilation of electron-positron pairs

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Huayu

    2011-04-27

    In this thesis we study multi-photon e{sup +}e{sup -} pair production in a trident process, and singlephoton e{sup +}e{sup -} pair annihilation in a triple interaction. The pair production is considered in the collision of a relativistic electron with a strong laser beam, and calculated within the theory of laser-dressed quantum electrodynamics. A regularization method is developed systematically for the resonance problem arising in the multi-photon process. Total production rates, positron spectra, and relative contributions of different reaction channels are obtained in various interaction regimes. Our calculation shows good agreement with existing experimental data from SLAC, and adds further insights into the experimental findings. Besides, we study the process in a manifestly nonperturbative domain, whose accessibility to future all-optical experiments based on laser acceleration is shown. In the single-photon e{sup +}e{sup -} pair annihilation, the recoil momentum is absorbed by a spectator particle. Various kinematic configurations of the three incoming particles are examined. Under certain conditions, the emitted photon exhibits distinct angular and polarization distributions which could facilitate the detection of the process. Considering an equilibrium relativistic e{sup +}e{sup -} plasma, it is found that the single-photon process becomes the dominant annihilation channel for plasma temperatures above 3 MeV. Multi-particle correlation effects are therefore essential for the e{sup +}e{sup -} dynamics at very high density. (orig.)

  1. Simulations On Pair Creation In Collision Of γ-Beams Produced With High Intensity Lasers

    Science.gov (United States)

    Jansen, Oliver; Ribeyre, Xavier; D'Humieres, Emmanuel; Jaquier, Sophie; Tikhonchuk, Vladimir

    2017-10-01

    Direct production of electron-positron pairs in two photon collisions, the Breit-Wheeler process, is one of the most basic processes in the universe. However, this process has never been directly observed in the laboratory due to the lack of high intensity γ sources. For a feasibility study and for the optimisation of experimental set-ups we developed a high-performance tree-code. Different possible set-ups with MeV photon sources were discussed and compared using collision detection for huge number of particles in a quantum-electrodynamic regime. For this we implemented bounding volume hierarchies in a tree-like code structure. We applied this code on the question whether the Texas Petawatt laser could produce a significant number of pairs within the framework of the NSF project National Science Foundation under Grant No. 1632777.

  2. Ultra-intense Pair Creation using the Texas Petawatt Laser and Applications

    Science.gov (United States)

    Liang, Edison; Henderson, Alexander; Clarke, Taylor; Lo, Willie; Chaguine, Petr; Dyer, Gilliss; Riley, Nathan; Serratto, Kristina; Donovan, Michael; Ditmire, Todd

    2014-10-01

    Pair plasmas and intense gamma-ray sources are ubiquitous in the high-energy universe, from pulser winds to gamma-ray bursts (GRB). Their study can be greatly enhanced if such sources can be recreated in the laboratory under controlled conditions. In 2012 and 2013, a joint Rice-University of Texas team performed over 130 laser shots on thick gold and platinum targets using the 100 Joule Texas Petawatt Laser in Austin. The laser intensity of many shots exceeded 1021 W.cm-2 with pulses as short as 130 fs. These experiments probe a new extreme regime of ultra-intense laser - high-Z solid target interactions never achieved before. In addition to creating copious pairs with the highest density (>1015/cc) and emergent e +/e- ratio exceeding 20% in many shots, these experiments also created the highest density multi-MeV gamma-rays, comparable in absolute numbers to those found inside a gamma-ray burst (GRB). Potential applications of such intense pair and gamma-ray sources to laboratory astrophysics and innovative technologies will be discussed. Work supported by DOE HEDLP program.

  3. Study of recombination processes for 'electron-hole' pairs in germanium irradiated by {gamma} rays from {sup 60}Co using the photovoltaic effect in P-N junctions; Etude du processus de recombinaison des paires ''electron-trou'' dans le germanium irradie par les rayons {gamma} du cobalt 60 a l'aide de l'effet photovoltaique dans les jonctions P-N

    Energy Technology Data Exchange (ETDEWEB)

    Zahedi-Mochadam, A.A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-10-01

    Using the photo-voltaic effect in p-n junctions, we have studied, during bombardment, the mechanism of the recombination of 'electron-hole' pairs in the presence of structure defects produced in germanium of the N and P types by {gamma} rays from a Co{sup 60} source. At 310 K the level of the recombination centres is situated 0.25 eV above the conduction band and the capture cross-sections of the holes and of the electrons have the respective values of: {sigma}{sub p} = 4 X 10{sup -15} cm{sup 2} and {sigma}{sub n} = 3 X 10{sup -15} cm{sup 2}. The value of {sigma}{sub n} appears to be under-estimated because the number of defects in P-type samples appears to be lower than that in N-type samples. These results lead to the conclusion that the interstitials are responsible for the recombination. At 80 K it has been found that in N-type samples, a shallow level exists at O.05 eV below the conduction band with a capture cross-section for the holes of {sigma}{sub p} {>=} 10{sup -14} cm{sup 2}. We believe that in this case the recombination of charge carriers is controlled by the neighbouring 'defect-interstitial' pairs. In P-type samples at low temperature, the life-time is practically constant during irradiation. This fact is attributed to a spontaneous annealing of defects ol purely electrical origin. In the last part of the work the study of the photo-voltaic effect applied to the problem of gamma radiation dosimetry is considered. It is shown that such dosimeters, based on this principle, make it possible to measure the intensity of gamma rays over a very wide range. (author) [French] En utilisant l'effet photovoltaique dans les jonctions p-n, nous avons etudie au cours du bombardement le mecanisme de recombinaison des paires 'electron-trou' en presence des defauts de structure introduits dans le germanium de type N et de type P par les rayons gamma d'une source de Co{sup 60}. A 310 K, le niveau des centres de recombinaison se

  4. Desorption by Femtosecond Laser Pulses : An Electron-Hole Effect?

    OpenAIRE

    D. M., NEWNS; T. F., HEINZ; J. A., MISEWICH; IBM Research Division, T. J. Watson Research Center; IBM Research Division, T. J. Watson Research Center; IBM Research Division, T. J. Watson Research Center

    1992-01-01

    Desorption of molecules from metal surfaces induced by femtosecond visible laser pulses has been reported. Since the lattice temperature rise is insufficient to explain desorption, an electronic mechanism is clearly responsible. It is shown that a theory based on direct coupling between the center-of-mass degree of freedom of the adsorbate and the electron-hole excitations of the substrate provides a satisfactory explanation of the various experimental findings.

  5. English semantic word-pair norms and a searchable Web portal for experimental stimulus creation.

    Science.gov (United States)

    Buchanan, Erin M; Holmes, Jessica L; Teasley, Marilee L; Hutchison, Keith A

    2013-09-01

    As researchers explore the complexity of memory and language hierarchies, the need to expand normed stimulus databases is growing. Therefore, we present 1,808 words, paired with their features and concept-concept information, that were collected using previously established norming methods (McRae, Cree, Seidenberg, & McNorgan Behavior Research Methods 37:547-559, 2005). This database supplements existing stimuli and complements the Semantic Priming Project (Hutchison, Balota, Cortese, Neely, Niemeyer, Bengson, & Cohen-Shikora 2010). The data set includes many types of words (including nouns, verbs, adjectives, etc.), expanding on previous collections of nouns and verbs (Vinson & Vigliocco Journal of Neurolinguistics 15:317-351, 2008). We describe the relation between our and other semantic norms, as well as giving a short review of word-pair norms. The stimuli are provided in conjunction with a searchable Web portal that allows researchers to create a set of experimental stimuli without prior programming knowledge. When researchers use this new database in tandem with previous norming efforts, precise stimuli sets can be created for future research endeavors.

  6. Polarimetry of cosmic gamma-ray sources above e+e- pair creation threshold

    Science.gov (United States)

    Bernard, D.

    2013-11-01

    We examine the potential for gamma-ray conversion to electron-positron pairs, either in the field of a nucleus or of an electron of a detector, to measure the fraction P of linear polarization of cosmic gamma sources. For this purpose we implement, validate and use an event generator based on the HELAS amplitude calculator and on the SPRING event generator. We characterize several ways to measure P. Past proposals to increase the polarization sensitivity by the selection of a fraction of the events in a subset of the available phase space are found to be inefficient, due to the loss in statistics. The use of an optimal variable that includes the full 5D probability density function is found to improve the precision of the measurement of P of a factor of approximately 2. We then study the dilution of the asymmetry that parametrize the degradation of the precision due to experimental effects such as multiple scattering. In a detector made with a succession of converter slabs and tracker foils, the dependence of the dilution is found to be different from that predicted assuming a given (the most probable) value of the pair opening angle. The limitations of a slab detector are avoided by the use of an active target, in which conversion and tracking are performed by the same device, in which case the dilution of the measurement of P is found to be manageable. Based on a realistic sizing of the detector, and for an effective exposure of 1 year, we estimate the precision for a Crab-like source on the full energy range to be approximately 1.4%.

  7. Structures of quantum 2D electron-hole plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Filinov, V S; Levashov, P R; Fortov, V E [Joint Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13 bldg 2, Moscow 125412 (Russian Federation); Bonitz, M [Christian-Albrechts-Universitaet zu Kiel, Institut fuer Theoretische Physik und Astrophysik, Leibnizstrasse 15, 24098 Kiel (Germany); Fehske, H [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Felix-Hausdorff-Str 6, D-17489 Greifswald (Germany)

    2009-05-29

    We investigate structures of 2D quantum electron-hole (e-h) plasmas by the direct path integral Monte Carlo method (PIMC) in a wide range of temperature, density and hole-to-electron mass ratio. Our simulation includes a region of appearance and decay of the bound states (excitons and biexcitons), the Mott transition from the neutral e-h plasma to metallic-like clusters, formation from clusters of the hexatic-like liquid and formation of the crystal-like lattice.

  8. Structures of quantum 2D electron-hole plasmas

    OpenAIRE

    Filinov, V. S.; Bonitz, M.; Fehske, H.; Levashov, P. R.; Fortov, V. E.

    2008-01-01

    We investigate structures of 2D quantum electron-hole (e-h) plasmas by the direct path integral Monte Carlo method (PIMC) in a wide range of temperature, density and hole-to-electron mass ratio. Our simulation includes a region of appearance and decay of the bound states (excitons and biexcitons), the Mott transition from the neutral e-h plasma to metallic-like clusters, formation from clusters the hexatic-like liquid and formation of the crystal-like lattice.

  9. Electron holes observed in the Moon Plasma Wake

    Science.gov (United States)

    Hutchinson, I. H.; Malaspina, D.; Zhou, C.

    2017-10-01

    Electrostatic instabilities are predicted in the magnetized wake of plasma flowing past a non-magnetic absorbing object such as a probe or the moon. Analysis of the data from the Artemis satellites, now orbiting the moon at distances ten moon radii and less, shows very clear evidence of fast-moving isolated solitary potential structures causing bipolar electric field excursions as they pass the satellite's probes. These structures have all the hallmarks of electron holes: BGK solitons typically a few Debye-lengths in size, self-sustaining by a deficit of phase-space density on trapped orbits. Electron holes are now observed to be widespread in space plasmas. They have been observed in PIC simulations of the moon wake to be the non-linear consequence of the predicted electron instabilities. Simulations document hole prevalence, speed, length, and depth; and theory can explain many of these features from kinetic analysis. The solar wind wake is certainly the cause of the overwhelming majority of the holes observed by Artemis, because we observe almost all holes to be in or very near to the wake. We compare theory and simulation of the hole generation, lifetime, and transport mechanisms with observations. Work partially supported by NASA Grant NNX16AG82G.

  10. Transient terahertz spectroscopy of excitons and unbound carriers in quasi two-dimensional electron-hole gases

    Energy Technology Data Exchange (ETDEWEB)

    Kaindl, Robert A.; Hagele, D.; Carnahan, M. A.; Chemla, D. S.

    2008-09-11

    We report a comprehensive experimental study and detailed model analysis of the terahertz (THz) dielectric response and density kinetics of excitons and unbound electron-hole pairs in GaAs quantum wells. A compact expression is given, in absolute units, for the complex-valued THz dielectric function of intra-excitonic transitions between the 1s and higher-energy exciton and continuum levels. It closely describes the THz spectra of resonantly generated excitons. Exciton ionization and formation are further explored, where the THz response exhibits both intra-excitonic and Drude features. Utilizing a two-component dielectric function, we derive the underlying exciton and unbound pair densities. In the ionized state, excellent agreement is found with the Saha thermodynamic equilibrium, which provides experimental verification of the two-component analysis and density scaling. During exciton formation, in turn, the pair kinetics is quantitatively described by a Saha equilibrium that follows the carrier cooling dynamics. The THz-derived kinetics is, moreover, consistent with time-resolved luminescence measured for comparison. Our study establishes a basis for tracking pair densities via transient THz spectroscopy of photoexcited quasi-2D electron-hole gases.

  11. Reversible electron-hole separation in a hot carrier solar cell

    Science.gov (United States)

    Linke, Heiner

    Hot-carrier solar cells are envisioned to utilize energy filtering to extract power from photogenerated electron-hole pairs before they thermalize with the lattice, and thus potentially offer higher power conversion efficiency compared to conventional, single absorber solar cells. The efficiency of hot-carrier solar cells can be expected to strongly depend on the details of the energy filtering process, a relationship which to date has not been satisfactorily explored. Here, we establish the conditions under which electron-hole separation in hot-carrier solar cells can occur reversibly, that is, at maximum energy conversion efficiency. We find that, under specific conditions, the energy conversion efficiency of a hot-carrier solar cell can exceed the Carnot limit set by the intra-device temperature gradient alone, due to the additional contribution of the quasi-Fermi level splitting in the absorber. To achieve this, we consider a highly selective energy filter such as a quantum dot embedded into a one-dimensional conductor. We also establish that the open-circuit voltage of a hot-carrier solar cell is not limited by the band gap of the absorber, due to the additional thermoelectric contribution to the voltage. Additionally, we find that a hot-carrier solar cell can be operated in reverse as a thermally driven solid-state light emitter. In addition this theoretical analysis, I will also report on first experimental results in a nanowire-based energy filter device. Ref: S Limpert, S Bremner, and H Linke, New J. Phys 17, 095004 (2015)

  12. Exciton formation and dissociation in mass-asymmetric electron-hole plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Fehske, H [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Domstrasse 10a, D-17489 Greifswald (Germany); Filinov, V [Institute for High Energy Density, Russian Academy of Sciences, Izhorskay 13/19, Moscow 127412 (Russian Federation); Bonitz, M [Christian-Albrechts-Universitaet zu Kiel, Institut fuer Theoretische Physik und Astrophysik, Lehrstuhl Statistische Physik, Leibnizstrasse 15, 24098 Kiel (Germany); Fortov, V [Institute for High Energy Density, Russian Academy of Sciences, Izhorskay 13/19, Moscow 127412 (Russian Federation); Levashov, P [Institute for High Energy Density, Russian Academy of Sciences, Izhorskay 13/19, Moscow 127412 (Russian Federation)

    2005-01-01

    First-principle path integral Monte Carlo simulations were performed in order to analyze correlation effects in complex electron-hole plasmas, particularly with regard to the appearance of excitonic bound states. Results are discussed in relation to exciton formation in unconventional semiconductors with large electron hole mass asymmetry.

  13. Non-linear Plasma Wake Growth of Electron Holes

    CERN Document Server

    Hutchinson, I H; Zhou, C

    2015-01-01

    An object's wake in a plasma with small Debye length that drifts \\emph{across} the magnetic field is subject to electrostatic electron instabilities. Such situations include, for example, the moon in the solar wind wake and probes in magnetized laboratory plasmas. The instability drive mechanism can equivalently be considered drift down the potential-energy gradient or drift up the density-gradient. The gradients arise because the plasma wake has a region of depressed density and electrostatic potential into which ions are attracted along the field. The non-linear consequences of the instability are analysed in this paper. At physical ratios of electron to ion mass, neither linear nor quasilinear treatment can explain the observation of large-amplitude perturbations that disrupt the ion streams well before they become ion-ion unstable. We show here, however, that electron holes, once formed, continue to grow, driven by the drift mechanism, and if they remain in the wake may reach a maximum non-linearly stable...

  14. Diffusive scattering of electrons by electron holes around injection fronts

    Science.gov (United States)

    Vasko, I. Y.; Agapitov, O. V.; Mozer, F. S.; Artemyev, A. V.; Krasnoselskikh, V. V.; Bonnell, J. W.

    2017-03-01

    Van Allen Probes have detected nonlinear electrostatic spikes around injection fronts in the outer radiation belt. These spikes include electron holes (EH), double layers, and more complicated solitary waves. We show that EHs can efficiently scatter electrons due to their substantial transverse electric fields. Although the electron scattering driven by EHs is diffusive, it cannot be evaluated via the standard quasi-linear theory. We derive analytical formulas describing local electron scattering by a single EH and verify them via test particle simulations. We show that the most efficiently scattered are gyroresonant electrons (crossing EH on a time scale comparable to the local electron gyroperiod). We compute bounce-averaged diffusion coefficients and demonstrate their dependence on the EH spatial distribution (latitudinal extent and spatial filling factor) and individual EH parameters (amplitude of electrostatic potential, velocity, and spatial scales). We show that EHs can drive pitch angle scattering of ≲5 keV electrons at rates 10-2-10-4 s-1 and, hence, can contribute to electron losses and conjugated diffuse aurora brightenings. The momentum and pitch angle scattering rates can be comparable, so that EHs can also provide efficient electron heating. The scattering rates driven by EHs at L shells L ˜ 5-8 are comparable to those due to chorus waves and may exceed those due to electron cyclotron harmonics.

  15. Crystallization in mass-asymmetric electron-hole bilayers

    Science.gov (United States)

    Ludwig, P.; Filinov, A.; Bonitz, M.; Stolz, H.; Lozovik, Yu. E.

    2007-03-01

    We analyze hole crystallization [1] in an electron-hole bilayer system and specifically study the effect of the hole to electron mass ratio M. Varying M between 1 and 100 at a fixed layer separation at low temperature and high density, we demonstrate that the hole behavior can be tuned from delocalized (liquid-like) to localized (crystal-like), while the electrons remain delocalized all the time. As was recently demonstrated [1] in bulk systems holes undergo a crystallization transition if M exceeds a critical value of 83. Here we extend this analysis to bilayer systems and demonstrate that the critical mass ratio can be drastically reduced by properly choosing the layer separation. The complicated interplay between Coulomb correlations and quantum effects of electrons and holes is fully taken into account by performing first principle path integral Monte Carlo simulations. [1] M. Bonitz, V.S. Filinov, V.E. Fortov, P.R. Levashov, and H. Fehske, Phys. Rev. Lett. 95, 235006 (2005) and J. Phys. A: Math. Gen. 39, 4717 (2006); Phys. Rev. Focus, December 2 2005 [2] P. Ludwig, A. Filinov, Yu. Lozovik, H. Stolz, and M. Bonitz, Contrib. Plasma Phys. (2007)

  16. Effect of heterojunction on exciton binding energy and electron-hole recombination probability in CdSe/ZnS quantum dots.

    Science.gov (United States)

    Elward, Jennifer M; Chakraborty, Arindam

    2015-02-10

    Presence of heterojunctions is important for generation of free charge carriers and the dissociation of bound electron-hole pairs in semiconductor nanoparticles. This work presents a theoretical investigation of the effect of core/shell heterojunction on electron-hole interaction in CdSe/ZnS quantum dots. The excitonic wave function in the CdSe/ZnS dots was calculated using the electron-hole explicitly correlated Hartree-Fock (eh-XCHF) method and the effect of successive addition of the ZnS shell on exciton binding energy, electron-hole recombination probability, and the electron-hole separation distance was investigated. It was found that the scaling of all the three quantities as a function of dot diameter did not follow conventional volume scaling laws of core-only dots, and the scaling laws were significantly altered due to the presence of the heterojunction. The spatial localization of the quasiparticles in the core/shell quantum dot was analyzed by calculating the 1-particle reduced density from the eh-XCHF wave function and partitioning the density spatially into core and shell regions. It was found that in the 15 nm CdSe/ZnS dot, the relative probability of the electron localization in the shell region was higher than the hole by a factor of 3. The degree of spatial localization of the quasiparticles was found to depend strongly on the initial size of the CdSe core in the core/shell quantum dot. It was found that a reduction in the CdSe core diameter by a factor of 1.7 resulted in an enhancement of the preferential localization of the electron in the shell region by a factor of 11.3. The results demonstrate that large CdSe/ZnS quantum dots with a small CdSe core have the necessary characteristics for efficient exciton dissociation and generation of free charge carriers.

  17. Order enables efficient electron-hole separation at an organic heterojunction with a small energy loss

    KAUST Repository

    Menke, S. Matthew

    2018-01-12

    Donor–acceptor organic solar cells often show low open-circuit voltages (VOC) relative to their optical energy gap (Eg) that limit power conversion efficiencies to ~12%. This energy loss is partly attributed to the offset between Eg and that of intermolecular charge transfer (CT) states at the donor–acceptor interface. Here we study charge generation occurring in PIPCP:PC61BM, a system with a very low driving energy for initial charge separation (Eg−ECT ~ 50 meV) and a high internal quantum efficiency (ηIQE ~ 80%). We track the strength of the electric field generated between the separating electron-hole pair by following the transient electroabsorption optical response, and find that while localised CT states are formed rapidly (<100 fs) after photoexcitation, free charges are not generated until 5 ps after photogeneration. In PIPCP:PC61BM, electronic disorder is low (Urbach energy <27 meV) and we consider that free charge separation is able to outcompete trap-assisted non-radiative recombination of the CT state.

  18. Novel detection methods for radiation-induced electron-hole pairs.

    Energy Technology Data Exchange (ETDEWEB)

    Nordquist, Christopher Daniel; Cich, Michael Joseph; Vawter, Gregory Allen; Derzon, Mark Steven; Martinez, Marino John

    2010-09-01

    Most common ionizing radiation detectors typically rely on one of two general methods: collection of charge generated by the radiation, or collection of light produced by recombination of excited species. Substantial efforts have been made to improve the performance of materials used in these types of detectors, e.g. to raise the operating temperature, to improve the energy resolution, timing or tracking ability. However, regardless of the material used, all these detectors are limited in performance by statistical variation in the collection efficiency, for charge or photons. We examine three alternative schemes for detecting ionizing radiation that do not rely on traditional direct collection of the carriers or photons produced by the radiation. The first method detects refractive index changes in a resonator structure. The second looks at alternative means to sense the chemical changes caused by radiation on a scintillator-type material. The final method examines the possibilities of sensing the perturbation caused by radiation on the transmission of a RF transmission line structure. Aspects of the feasibility of each approach are examined and recommendations made for further work.

  19. Vlasov simulations of electron hole dynamics in inhomogeneous magnetic field

    Science.gov (United States)

    Kuzichev, Ilya; Vasko, Ivan; Agapitov, Oleksiy; Mozer, Forrest; Artemyev, Anton

    2017-04-01

    Electron holes (EHs) or phase space vortices are solitary electrostatic waves existing due to electrons trapped within EH electrostatic potential. Since the first direct observation [1], EHs have been widely observed in the Earth's magnetosphere: in reconnecting current sheets [2], injection fronts [3], auroral region [4], and many other space plasma systems. EHs have typical spatial scales up to tens of Debye lengths, electric field amplitudes up to hundreds of mV/m and propagate along magnetic field lines with velocities of about electron thermal velocity [5]. The role of EHs in energy dissipation and supporting of large-scale potential drops is under active investigation. The accurate interpretation of spacecraft observations requires understanding of EH evolution in inhomogeneous plasma. The critical role of plasma density gradients in EH evolution was demonstrated in [6] using PIC simulations. Interestingly, up to date no studies have addressed a role of magnetic field gradients in EH evolution. In this report, we use 1.5D gyrokinetic Vlasov code to demonstrate the critical role of magnetic field gradients in EH dynamics. We show that EHs propagating into stronger (weaker) magnetic field are decelerated (accelerated) with deceleration (acceleration) rate dependent on the magnetic field gradient. Remarkably, the reflection points of decelerating EHs are independent of the average magnetic field gradient in the system and depend only on the EH parameters. EHs are decelerated (accelerated) faster than would follow from the "quasi-particle" concept assuming that EH is decelerated (accelerated) entirely due to the mirror force acting on electrons trapped within EH. We demonstrate that EH propagation in inhomogeneous magnetic fields results in development of a net potential drop along an EH, which depends on the magnetic field gradient. The revealed features will be helpful for interpreting spacecraft observations and results of advanced particle simulations. In

  20. Transient evolution of solitary electron holes in low pressure laboratory plasma

    CERN Document Server

    Choudhary, Mangilal; Mukherjee, Subroto

    2015-01-01

    Solitary electrons holes (SEHs) are localized electrostatic positive potential structures in collisionless plasmas. These are vortex-like structures in the electron phase space. Its existence is cause of distortion of the electron distribution in the resonant region. These are explained theoretically first time by Schamel et.al [Phys. Scr. 20, 336 (1979) and Phys. Plasmas 19, 020501 (2012)]. Propagating solitary electron holes can also be formed in a laboratory plasma when a fast rising high positive voltage pulse is applied to a metallic electrode [Kar et. al., Phys. Plasmas 17, 102113 (2010)] immersed in a low pressure plasma. The temporal evolution of these structures can be studied by measuring the transient electron distribution function (EDF). In the present work, transient EDF is measured after formation of a solitary electron hole in nearly uniform, unmagnetized, and collisionless plasma for applied pulse width and, where and are applied pulse width and inverse of ion plasma frequency respectively. Fo...

  1. Plasma phase transition in dense hydrogen and electron-hole plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Filinov, V S [Institute for High Energy Density, Russian Academy of Sciences, Izhorskay 13/19, Moscow 127412, Russia (Russian Federation); Bonitz, M [Fachbereich Physik, Universitaet Rostock, D-18051 Rostock (Germany); Levashov, P [Institute for High Energy Density, Russian Academy of Sciences, Izhorskay 13/19, Moscow 127412, Russia (Russian Federation); Fortov, V E [Institute for High Energy Density, Russian Academy of Sciences, Izhorskay 13/19, Moscow 127412, Russia (Russian Federation); Ebeling, W [Institut fuer Physik, Humboldt-Universitaet Berlin, Invalidenstrasse 110, D-10115 Berlin (Germany); Schlanges, M [Fachbereich Physik, Universitaet Greifswald, D-17489 Greifswald (Germany); Koch, S W [Fachbereich Physik, Philipps-Universitaet Marburg, D-35032 Marburg (Germany)

    2003-06-06

    Plasma phase transitions in dense hydrogen and electron-hole plasmas are investigated by direct path integral Monte Carlo methods. The phase boundary of the electron-hole liquid in germanium is calculated and is found to agree reasonably well with the known experimental results. Analogous behaviour is found for high-density hydrogen. For a temperature of T = 10 000 K it is shown that the internal energy is lowered due to droplet formation for densities between 10{sup 23} cm{sup -3} and 10{sup 24} cm{sup -3}.

  2. Plasma phase transition in dense hydrogen and electron-hole plasmas

    CERN Document Server

    Filinov, V S; Levashov, P R; Fortov, V E; Ebeling, W; Schlanges, M; Koch, S W

    2003-01-01

    Plasma phase transitions in dense hydrogen and electron-hole plasmas are investigated by direct path integral Monte Carlo methods. The phase boundary of the electron-hole liquid in germanium is calculated and is found to agree reasonably well with the known experimental results. Analogous behaviour is found for high-density hydrogen. For a temperature of T = 10 000 K it is shown that the internal energy is lowered due to droplet formation for densities between 10 sup 2 sup 3 cm sup - sup 3 and 10 sup 2 sup 4 cm sup - sup 3.

  3. Ordered structure formation in 2D mass asymmetric electron-hole plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Filinov, V.S. [Institute for High Energy Density, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 127412 (Russian Federation)], E-mail: vladimir_filinov@mail.ru; Fehske, H. [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Felix-Hausdorff-Str. 6, D-17489 Greifswald (Germany); Bonitz, M. [Christian-Albrechts-Universitaet zu Kiel, Institut fuer Theoretische Physik und Astrophysik, Leibnizstrasse 15, 24098 Kiel (Germany); Fortov, V.E.; Levashov, P. [Institute for High Energy Density, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 127412 (Russian Federation)

    2008-07-28

    We study strong Coulomb correlations in dense two-dimensional electron-hole plasmas by means of direct path integral Monte Carlo simulations. In particular, the formation and dissociation of bound states, such as excitons, bi-excitons and many particle clusters, is analyzed and the density-temperature regions of their occurrence are identified. At high density, the Mott transition to the fully ionized state (electron-hole hexatic liquid) is detected. Particular attention is paid to the influence of the hole to electron mass ratio M on the properties of the plasma. For high enough values of M we observed the formation of Coulomb hole crystal-like structures.

  4. Electron holes appear to trigger cancer-implicated mutations

    Science.gov (United States)

    Miller, John; Villagran, Martha

    Malignant tumors are caused by mutations, which also affect their subsequent growth and evolution. We use a novel approach, computational DNA hole spectroscopy [M.Y. Suarez-Villagran & J.H. Miller, Sci. Rep. 5, 13571 (2015)], to compute spectra of enhanced hole probability based on actual sequence data. A hole is a mobile site of positive charge created when an electron is removed, for example by radiation or contact with a mutagenic agent. Peaks in the hole spectrum depict sites where holes tend to localize and potentially trigger a base pair mismatch during replication. Our studies of reveal a correlation between hole spectrum peaks and spikes in human mutation frequencies. Importantly, we also find that hole peak positions that do not coincide with large variant frequencies often coincide with cancer-implicated mutations and/or (for coding DNA) encoded conserved amino acids. This enables combining hole spectra with variant data to identify critical base pairs and potential cancer `driver' mutations. Such integration of DNA hole and variance spectra could also prove invaluable for pinpointing critical regions, and sites of driver mutations, in the vast non-protein-coding genome. Supported by the State of Texas through the Texas Ctr. for Superconductivity.

  5. Mapping of electron-hole excitations in the charge-density-wave system 1T-TiSe2 using resonant inelastic x-ray scattering.

    Science.gov (United States)

    Monney, C; Zhou, K J; Cercellier, H; Vydrova, Z; Garnier, M G; Monney, G; Strocov, V N; Berger, H; Beck, H; Schmitt, T; Aebi, P

    2012-07-27

    In high-resolution resonant inelastic x-ray scattering at the Ti L edge of the charge-density-wave system 1T-TiSe(2), we observe sharp low energy loss peaks from electron-hole pair excitations developing at low temperature. These excitations are strongly dispersing as a function of the transferred momentum of light. We show that the unoccupied bands close to the Fermi level can effectively be probed in this broadband material. Furthermore, we extract the order parameter of the charge-density-wave phase from temperature-dependent measurements.

  6. Nucleation phenomena in the formation of electron-hole drops in Ge

    Energy Technology Data Exchange (ETDEWEB)

    Westervelt, R.M.

    1977-09-01

    A detailed theory of the nucleation of electron-hole drops from a gas of free excitons in Ge is presented, together with a systematic experimental study of hysteresis and threshold phenomena in the luminescence of optically excited crystals of ultrapure Ge.

  7. Electron holes in phase space: What they are and why they matter

    Science.gov (United States)

    Hutchinson, I. H.

    2017-05-01

    This is a tutorial and selective review explaining the fundamental concepts and some currently open questions concerning the plasma phenomenon of the electron hole. The widespread occurrence of electron holes in numerical simulations, space-craft observations, and laboratory experiments is illustrated. The elementary underlying theory is developed of a one-dimensional electron hole as a localized potential maximum, self-consistently sustained by a deficit of trapped electron phase-space density. The spatial extent of a hole is typically a few Debye lengths; what determines the minimum and maximum possible lengths is explained, addressing the key aspects of the as yet unsettled dispute between the integral and differential approaches to hole structure. In multiple dimensions, holes tend to form less readily; they generally require a magnetic field and distribution-function anisotropy. The mechanisms by which they break up are explained, noting that this transverse instability is not fully understood. Examples are given of plasma circumstances where holes play an important role, and of recent progress on understanding their holistic kinematics and self-acceleration.

  8. Two-particle self-consistent analysis for the electron-hole asymmetry of superconductivity in cuprate superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Ogura, Daisuke; Kuroki, Kazuhiko [Department of Physics, Graduate School of Science, Osaka University, Toyonaka (Japan)

    2017-06-15

    In the hole-doped type cuprate superconductors, it is well-known that the superconducting transition temperature T{sub c} exhibits a dome-like structure against doping. On the other hand, recent experiments unveil that T{sub c} in the electron-doped compounds shows a monotonic increase with decreasing the doping, at least down to a very small doping rate. Our recent study for the three-band d-p model has unveiled that this asymmetric behavior can be explained as a combined effect of the intrinsic electron-hole asymmetry in systems comprising Cu3 d and O2 p orbitals and the band-filling-dependent vertex correction. In the present study, we study another compound Tl{sub 2} Ba{sub 2} CuO{sub 6} to show that this explanation can be applied to other cuprate superconductors with the small d{sub z{sup 2}} orbital mixture. By varying the d-p offset, we also study how the strength of the d-p hybridization controls the spin fluctuation and hence the pairing interaction. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Potential beneficial effects of electron-hole plasmas created in silicon sensors by XFEL-like high intensity pulses for detector development

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Joel T.; Becker, Julian; Shanks, Katherine S.; Philipp, Hugh T.; Tate, Mark W. [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Gruner, Sol M., E-mail: smg26@cornell.edu [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States)

    2016-07-27

    There is a compelling need for a high frame rate imaging detector with a wide dynamic range, from single x-rays/pixel/pulse to >10{sup 6} x-rays/pixel/pulse, that is capable of operating at both x-ray free electron laser (XFEL) and 3rd generation sources with sustained fluxes of > 10{sup 11} x-rays/pixel/s [1, 2, 3]. We propose to meet these requirements with the High Dynamic Range Pixel Array Detector (HDR-PAD) by (a) increasing the speed of charge removal strategies [4], (b) increasing integrator range by implementing adaptive gain [5], and (c) exploiting the extended charge collection times of electron-hole pair plasma clouds that form when a sufficiently large number of x-rays are absorbed in a detector sensor in a short period of time [6]. We have developed a measurement platform similar to the one used in [6] to study the effects of high electron-hole densities in silicon sensors using optical lasers to emulate the conditions found at XFELs. Characterizations of the employed tunable wavelength laser with picosecond pulse duration have shown Gaussian focal spots sizes of 6 ± 1 µm rms over the relevant spectrum and 2 to 3 orders of magnitude increase in available intensity compared to previous measurements presented in [6]. Results from measurements on a typical pixelated silicon diode intended for use with the HDR-PAD (150 µm pixel size, 500 µm thick sensor) are presented.

  10. Theoretical Phase Diagram for the Room-Temperature Electron-Hole Liquid in Photoexcited Quasi-Two-Dimensional Monolayer MoS2.

    Science.gov (United States)

    Rustagi, Avinash; Kemper, Alexander F

    2017-12-12

    Strong correlations between electrons and holes can drive the existence of an electron-hole liquid (EHL) state, typically at high carrier densities and low temperatures. The recent emergence of quasi-two-dimensional (2D) monolayer transition metal dichalcogenides (TMDCs) provides ideal systems to explore the EHL state since ineffective screening of the out-of-plane field lines in these quasi-2D systems allows for stronger charge carrier correlations in contrast to conventional 3D bulk semiconductors and enables the existence of the EHL at high temperatures. Here we construct the phase diagram for the photoinduced first-order phase transition from a plasma of electron-hole pairs to a correlated EHL state in suspended monolayer MoS2. We show that the quasi-2D nature of monolayer TMDCs and the ineffective screening of the out-of-plane field lines allow for this phase transition to occur at and above room temperature, thereby opening avenues for studying many-body phenomena without the constraint of cryogenics.

  11. Impact of electron-hole correlations on the 1T-TiSe_{2} electronic structure.

    Science.gov (United States)

    Monney, G; Monney, C; Hildebrand, B; Aebi, P; Beck, H

    2015-02-27

    Several experiments have been performed on 1T-TiSe_{2} in order to identify whether the electronic structure is semimetallic or semiconducting without reaching a consensus. In this Letter, we theoretically study the impact of electron-hole and electron-phonon correlations on the bare semimetallic and semiconducting electronic structure. The resulting electron spectral functions provide a direct comparison of both cases and demonstrate that 1T-TiSe_{2} is of predominant semiconducting character with some spectral weight crossing the Fermi level.

  12. Coupled electron-hole bilayer graphene sheets: Superfluidity, Charge Density Waves, and Coupled Wigner Crystals

    Science.gov (United States)

    Zarenia, Mohammad; Peeters, Francois; Neilson, David

    The juxtaposition of superconducting and charge density wave (CDW) phases that is often observed in connection with High-Temperature Superconductors, is attracting considerable attention. In these systems, the crystal lattice provides a polarizable background, needed to drive the CDW phase. We report on a different system that exhibits the association of superfluid and CDW phases, but in which the polarizable background is uniform. Our system consists of two coupled two-dimensional bilayers of graphene, one bilayer containing electrons and the other holes interacting through the long range Coulomb interaction. To account for the inter-layer correlation energy accurately, we introduce a new approach which is based on the random phase approximation at high densities and interpolation between the weakly- and strongly-interacting regimes. We determine the zero temperature phase diagram in which the two control parameters are the equal electron and hole densities and the thickness of the insulating barrier separating the two bilayers. We find in addition to an electron-hole superfluid and a one-dimensional CDW phases that there exist also a coupled electron-hole Wigner crystal. The structure of the crystal background plays no role in determining the phase diagram. This work was supported by the Flemish Science Foundation (FWO).

  13. Transport Properties of an Electron-Hole Bilayer in Contact with a Superconductor Hybrid Junction.

    Science.gov (United States)

    Bercioux, D; Klapwijk, T M; Bergeret, F S

    2017-08-11

    We investigate the transport properties of a junction consisting of an electron-hole bilayer in contact with normal and superconducting leads. The electron-hole bilayer is considered as a semimetal with two electronic bands. We assume that in the region between the contacts the system hosts an exciton condensate described by a BCS-like model with a gap Γ in the quasiparticle density of states. We first discuss how the subgap electronic transport through the junction is mainly governed by the interplay between two kinds of reflection processes at the interfaces: the standard Andreev reflection at the interface between the superconductor and the exciton condensate, and a coherent crossed reflection at the semimetal-exciton-condensate interface that converts electrons from one layer into the other. We show that the differential conductance of the junction shows a minimum at voltages of the order of Γ/e. Such a minimum can be seen as a direct hallmark of the existence of the gapped excitonic state.

  14. Plasma electron hole kinematics. II. Hole tracking Particle-In-Cell simulation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, C.; Hutchinson, I. H. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2016-08-15

    The kinematics of a 1-D electron hole is studied using a novel Particle-In-Cell simulation code. A hole tracking technique enables us to follow the trajectory of a fast-moving solitary hole and study quantitatively hole acceleration and coupling to ions. We observe a transient at the initial stage of hole formation when the hole accelerates to several times the cold-ion sound speed. Artificially imposing slow ion speed changes on a fully formed hole causes its velocity to change even when the ion stream speed in the hole frame greatly exceeds the ion thermal speed, so there are no reflected ions. The behavior that we observe in numerical simulations agrees very well with our analytic theory of hole momentum conservation and the effects of “jetting.”.

  15. Sum rules for electron-hole bilayer and two-dimensional point dipole systems.

    Science.gov (United States)

    Golden, Kenneth I; Kalman, Gabor J

    2013-09-01

    We formulate and analyze the third-frequency-moment sum rules for the two-dimensional (point) dipole system (2DDS) and the mass-symmetric electron-hole bilayer (EHB) in their strongly coupled liquid phases. The former, characterized by the repulsive interaction potential φ_{D}(r)=μ^{2}/r^{3} (μ is the electric dipole moment), reasonably well approximates the latter in the d → 0 limit (d is the interlayer spacing), a conjecture that is further supported by the findings of the present work. We explore the extent to which the in-phase sum rule for the closely spaced EHB may or may not reconcile with its 2DDS sum-rule counterpart. This is the main emphasis of the present work.

  16. Correlated electron-hole mechanism for molecular doping in organic semiconductors

    Science.gov (United States)

    Li, Jing; D'Avino, Gabriele; Pershin, Anton; Jacquemin, Denis; Duchemin, Ivan; Beljonne, David; Blase, Xavier

    2017-07-01

    The electronic and optical properties of the paradigmatic F4TCNQ-doped pentacene in the low-doping limit are investigated by a combination of state-of-the-art many-body ab initio methods accounting for environmental screening effects, and a carefully parametrized model Hamiltonian. We demonstrate that while the acceptor level lies very deep in the gap, the inclusion of electron-hole interactions strongly stabilizes dopant-semiconductor charge transfer states and, together with spin statistics and structural relaxation effects, rationalize the possibility for room-temperature dopant ionization. Our findings reconcile available experimental data, shedding light on the partial vs. full charge transfer scenario discussed in the literature, and question the relevance of the standard classification in shallow or deep impurity levels prevailing for inorganic semiconductors.

  17. Disorder and magnetic-field-induced breakdown of helical edge conduction in an inverted electron-hole bilayer

    NARCIS (Netherlands)

    Pikulin, D.I.; Hyart, T.; Mi, S.; Tworzydlo, J.; Wimmer, M.T.; Beenakker, C.W.J.

    2014-01-01

    We calculate the conductance of a two-dimensional bilayer with inverted electron-hole bands to study the sensitivity of the quantum spin Hall insulator (with helical edge conduction) to the combination of electrostatic disorder and a perpendicular magnetic field. The characteristic breakdown field

  18. About the creation of proton–antiproton pair at electron–positron collider in the energy range of ψ(3770 mass

    Directory of Open Access Journals (Sweden)

    A.I. Ahmadov

    2014-11-01

    Full Text Available The process of electron–positron annihilation into proton–antiproton pair is considered within the vicinity of ψ(3770 resonance. The interference between the pure electromagnetic intermediate state and the ψ(3770 state is evaluated. It is shown that this interference is destructive and the relative phase between these two contributions is large (ϕ0≈250°.

  19. About the creation of proton-antiproton pair at electron-positron collider in the energy range of ψ(3770) mass

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadov, A.I., E-mail: ahmadov@theor.jinr.ru [Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region (Russian Federation); Institute of Physics, Azerbaijan National Academy of Science, Baku (Azerbaijan); Bystritskiy, Yu.M., E-mail: bystr@theor.jinr.ru [Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region (Russian Federation); Kuraev, E.A. [Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region (Russian Federation); Wang, P., E-mail: wangp@ihep.ac.cn [Institute of High Energy Physic, Chinese Academy of Science (China)

    2014-11-15

    The process of electron-positron annihilation into proton-antiproton pair is considered within the vicinity of ψ(3770) resonance. The interference between the pure electromagnetic intermediate state and the ψ(3770) state is evaluated. It is shown that this interference is destructive and the relative phase between these two contributions is large (ϕ{sub 0}≈250°)

  20. Giant electron-hole transport asymmetry in ultra-short quantum transistors.

    Science.gov (United States)

    McRae, A C; Tayari, V; Porter, J M; Champagne, A R

    2017-05-31

    Making use of bipolar transport in single-wall carbon nanotube quantum transistors would permit a single device to operate as both a quantum dot and a ballistic conductor or as two quantum dots with different charging energies. Here we report ultra-clean 10 to 100 nm scale suspended nanotube transistors with a large electron-hole transport asymmetry. The devices consist of naked nanotube channels contacted with sections of tube under annealed gold. The annealed gold acts as an n-doping top gate, allowing coherent quantum transport, and can create nanometre-sharp barriers. These tunnel barriers define a single quantum dot whose charging energies to add an electron or a hole are vastly different (e-h charging energy asymmetry). We parameterize the e-h transport asymmetry by the ratio of the hole and electron charging energies ηe-h. This asymmetry is maximized for short channels and small band gap tubes. In a small band gap device, we demonstrate the fabrication of a dual functionality quantum device acting as a quantum dot for holes and a much longer quantum bus for electrons. In a 14 nm-long channel, ηe-h reaches up to 2.6 for a device with a band gap of 270 meV. The charging energies in this device exceed 100 meV.

  1. Unconventional superconductivity in generalized Hubbard model: role of electron-hole symmetry breaking terms.

    Science.gov (United States)

    Wysokiński, Marcin M; Kaczmarczyk, Jan

    2017-03-01

    We investigate the effect of the electron-hole (e-h) symmetry breaking on d-wave superconductivity induced by non-local effects of correlations in the generalized Hubbard model. The symmetry breaking is introduced in a two-fold manner: by the next-to-nearest neighbor hopping of electrons and by the charge-bond interaction-the off-diagonal term of the Coulomb potential. Both terms lead to a pronounced asymmetry of the superconducting order parameter. The next-to-nearest neighbor hopping enhances superconductivity for h-doping, while diminishes it for e-doping. The charge-bond interaction alone leads to the opposite effect and, additionally, to the kinetic-energy gain upon condensation in the underdoped regime. With both terms included, with similar amplitudes, the height of the superconducting dome and the critical doping remain in favor of h-doping. The influence of the charge-bond interaction on deviations from [Formula: see text] symmetry of the shape of the gap at the Fermi surface in the momentum space is briefly discussed.

  2. Electron-hole capture in polymer heterojunction light-emitting diodes

    Science.gov (United States)

    Greenham, Neil

    2005-03-01

    Polymer light-emitting diodes based on blends of polyfluorene derivatives show very high efficiencies and low drive voltages. Electron-hole capture in these devices directly produces long-lived exciplex states where the electron and hole are predominantly localized on opposite sides of the heterojunction. The exciplex may then be thermally excited to form an intra-chain exciton, which can itself either emit, or be recycled to reform the exciplex. I will review the physics of exciplex formation and emission in these devices, and will show that exciplex formation rates are consistent with low free charge densities at the heterojunction. I will present evidence that the rate of charge transfer at polyfluorene heterojunctions can be modulated with an applied electric field, leading in some cases to an increase in photoluminescence efficiency with applied field. I will also present recent results showing enhanced triplet exciton formation after photoexcitation in polyfluorene blends, and will discuss the implications of the results for polymer light-emitting and photovoltaic devices.

  3. Energy-conserving numerical simulations of electron holes in two-species plasmas

    Science.gov (United States)

    Cheng, Yingda; Christlieb, Andrew J.; Zhong, Xinghui

    2015-03-01

    In this paper, we apply our recently developed energy-conserving discontinuous Galerkin (DG) methods for the two-species Vlasov-Ampère system to simulate the evolution of electron holes (EHs). The EH is an important Bernstein-Greene-Kurskal (BGK) state and is constructed based on the Schamel distribution in our simulation.Even though the knowledge of steady state EHs has advanced significantly, little is known about the full dynamics of EHs that nonlinearly interact with ions in plasmas. In this paper, we simulate the full dynamics of EHs with DG finite element methods, coupled with explicit and implicit time integrators. Our methods are demonstrated to be conservative in the total energy and particle numbers for both species. By varying the mass and temperature ratios, we observe the stationary and moving EHs, as well as the break up of EHs at later times upon initial perturbation of the electron distribution. In addition, we perform a detailed numerical study for the BGK states for the nonlinear evolutions of EH simulations. Our simulation results should help to understand the dynamics of large amplitude EHs that nonlinearly interact with ions in space and laboratory plasmas.

  4. Current densities due to electron-hole puddles in graphene flakes at the charge neutrality point

    Science.gov (United States)

    Lima, Leandro; Lewenkopf, Caio

    2014-03-01

    Graphene flakes show a typical conductivity minimum of about e2 / h , almost independent of sample mobility, at the charge neutrality point. This is at odds with the notion that as the mobility increases, and graphene becomes more ballistic, its density of states (DOS) and conductivity at the charge neutrality point should vanish. The observed conductivity minimum is often attributed to the presence of electron-hole charge puddles, that give rise to an effective local-dependent chemical potential. In this way, the local chemical potential fluctuates creating p and n-doped regions and the electronic transport is facilitated by Klein tunneling through the p and n-doped domains. Although very attractive, there is little quantitative support for this this picture. We revisit this problem and analyze the transport properties using a self-consistent recursive Green's functions technique with spin resolution that includes the electronic interaction modeled by a mean field Hubbard term. We calculate electronic current densities between neighboring carbon sites near the p-n interface and relate the electronic propagation to the puddles charge, size and shapes.

  5. Giant electron-hole transport asymmetry in ultra-short quantum transistors

    Science.gov (United States)

    McRae, A. C.; Tayari, V.; Porter, J. M.; Champagne, A. R.

    2017-05-01

    Making use of bipolar transport in single-wall carbon nanotube quantum transistors would permit a single device to operate as both a quantum dot and a ballistic conductor or as two quantum dots with different charging energies. Here we report ultra-clean 10 to 100 nm scale suspended nanotube transistors with a large electron-hole transport asymmetry. The devices consist of naked nanotube channels contacted with sections of tube under annealed gold. The annealed gold acts as an n-doping top gate, allowing coherent quantum transport, and can create nanometre-sharp barriers. These tunnel barriers define a single quantum dot whose charging energies to add an electron or a hole are vastly different (e-h charging energy asymmetry). We parameterize the e-h transport asymmetry by the ratio of the hole and electron charging energies ηe-h. This asymmetry is maximized for short channels and small band gap tubes. In a small band gap device, we demonstrate the fabrication of a dual functionality quantum device acting as a quantum dot for holes and a much longer quantum bus for electrons. In a 14 nm-long channel, ηe-h reaches up to 2.6 for a device with a band gap of 270 meV. The charging energies in this device exceed 100 meV.

  6. Watching the coherent birth of polaron pairs in conjugated polymers

    OpenAIRE

    De Sio, Antonietta; Troiani, Filippo; Maiuri, Margherita; Réhault, Julien; Sommer, Ephraim; Lim, James; Huelga, Susana F.; Plenio, Martin B.; Rozzi, Carlo Andrea; Cerullo, Giulio; Molinari, Elisa; Lienau, Christoph

    2016-01-01

    Organic semiconductors have the remarkable property that their optical excitation not only generates charge-neutral electron-hole pairs (excitons) but also charge-separated polaron pairs with high yield. The microscopic mechanisms underlying this charge separation have been debated for many years. Here we use ultrafast two-dimensional electronic spectroscopy to study the dynamics of polaron pair formation in a prototypical polymer thin film on a sub-20-fs time scale. We observe multi-period p...

  7. Electron-hole droplet formation in direct-gap semiconductors observed by mid-infrared pump-probe spectroscopy.

    Science.gov (United States)

    Nagai, M; Shimano, R; Kuwata-Gonokami, M

    2001-06-18

    Mid-infrared pump-probe measurements with subpicosecond time resolution reveal the existence of a metastable condensed phase of the electron-hole ensemble in a direct-gap semiconductor CuCl. High-density electrons and holes are directly created in a low-temperature state by the resonant femtosecond excitation of excitons above the Mott transition density. Strong metallic reflection with a plasma frequency Planck's over 2pi(omega)p approximately 0.5 eV builds up within 0.3 ps. Within a few picoseconds, the mid-infrared reflection spectrum is transformed from metalliclike into colloidlike. The observed resonance feature at Planck's over 2pi(omega)p/sqrt[3] allows us to obtain the carrier density in the metastable electron-hole droplets of 2x10(20) cm(-3).

  8. Light emission from thermally generated electron-hole plasma in a field-effect soi-transistor

    CERN Document Server

    Dobrovol's'kij, V M; Nyinyidze, G K; Pavlyuk, S P

    2002-01-01

    Field-effect silicon-on-insulator (SOI) transistors are investigated at extremely high drain currents.These currents heat the silicon film of a transistor and cause the generation of thermal electron-hole plasma there.We discovered the red light emission from such a plasma.Plasma stratification and formation of lighting spots are explained by the occurrence of thermodiffusion auto solitons.

  9. Electron holes in the outer radiation belt: Characteristics and their role in electron energization

    Science.gov (United States)

    Vasko, I. Y.; Agapitov, O. V.; Mozer, F. S.; Artemyev, A. V.; Drake, J. F.; Kuzichev, I. V.

    2017-01-01

    Van Allen Probes have detected electron holes (EHs) around injection fronts in the outer radiation belt. Presumably generated near equator, EHs propagate to higher latitudes potentially resulting in energization of electrons trapped within EHs. This process has been recently shown to provide electrons with energies up to several tens of keV and requires EH propagation up to rather high latitudes. We have analyzed more than 100 EHs observed around a particular injection to determine their kinetic structure and potential energy sources supporting the energization of trapped electrons. EHs propagate with velocities from 1000 to 20,000 km/s (a few times larger than the thermal velocity of the coldest background electron population). The parallel scale of observed EHs is from 0.3 to 3 km that is of the order of hundred Debye lengths. The perpendicular to parallel scale ratio is larger than one in a qualitative agreement with the theoretical scaling relation. The amplitudes of EH electrostatic potentials are generally below 100 V. We determine the properties of the electron population trapped within EHs by making use of the Bernstein-Green-Kruskal analysis and via analysis of EH magnetic field signatures. The density of the trapped electron population is on average 20% of the background electron density. The perpendicular temperature of the trapped population is on average 300 eV and is larger for faster EHs. We show that energy losses of untrapped electrons scattered by EHs in the inhomogeneous background magnetic field may balance the energization of trapped electrons.

  10. Time-Resolved EPR Study of Electron-Hole Dissociations Influenced by Alkyl Side Chains at the Photovoltaic Polyalkylthiophene:PCBM Interface.

    Science.gov (United States)

    Miura, Taku; Aikawa, Motoko; Kobori, Yasuhiro

    2014-01-02

    Nanosecond time-resolved electron paramagnetic resonance (TREPR) spectroscopy has been utilized at T = 77 K to characterize alkyl side-chain effects on geometries and on the electronic couplings (VCR) of transient charge-separated (CS) states in the photoactive layers fabricated by the spin-coating of mixed solutions of regioregular polyalkylthiophenes (RR-P3AT) and [6,6]-C61-butyric acid methyl ester (PCBM). By increasing the alkyl side-chain number from 6 to 12 in P3AT, a highly distant and long-lived CS state has been obtained. This result is explained by a coupling of the hole dissociation to the polymer librations by the side-chains. From an exponential decay of VCR with respect to the CS distance, the attenuation factor (βe) has been determined to be βe = 0.2 Å(-1). Such a long-range tunneling feature is explained by the generations of the shallowly trapped, delocalized electron-hole pairs by the dissociation of the hole toward π-stacking directions at the organic photovoltaic interface.

  11. Path Creation

    DEFF Research Database (Denmark)

    Karnøe, Peter; Garud, Raghu

    2012-01-01

    . Competencies emerged through processes and mechanisms such as co-creation that implicated multiple learning processes. The process was not an orderly linear one as emergent contingencies influenced the learning processes. An implication is that public policy to catalyse clusters cannot be based......This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts...

  12. Electron-hole exchange blockade and memory-less recombination in photoexcited films of colloidal quantum dots

    Science.gov (United States)

    Fidler, Andrew F.; Gao, Jianbo; Klimov, Victor I.

    2017-06-01

    Understanding charge transport and recombination dynamics in photoexcited colloidal quantum dot (QD) solids is key to their applications in optoelectronic devices. Towards this end, we conduct transient photocurrent studies of films of electronically coupled, device-grade PbSe QD films. We observe that the photocurrent amplitude detected following excitation with a short 100 fs pulse is virtually temperature independent down to 6 K, suggesting a tunnelling mechanism of early-time photoconductance. The later-time signal exhibits clear signatures of thermal activation with characteristic energies that are surprisingly robust and independent of the exact type of QD surface treatment. We attribute this behaviour to the involvement of intrinsic fine-structure states and specifically the electron-hole exchange interaction, which creates an energetic barrier to electron-hole separation between adjacent QDs. At room temperature, which is well above the largest activation energy, relaxation of photoconductivity is dominated by non-geminate recombination involving mobile band-edge carriers of one sign and low-mobility carriers of the opposite sign (pre-existing and photoexcited) residing in intragap states. This process leads to memory-less dynamics when the photocurrent relaxation time is directly linked to the instantaneous carrier density.

  13. Entropic Creation

    DEFF Research Database (Denmark)

    Kragh, Helge

    1860s it was pointed out that, as a consequence of the heat death scenario, the universe can have existed only for a finite period of time. According to the 'entropic creation argument', thermodynamics warrants the conclusion that the world once begun or was created. It is these two scenarios......Entropic Creation is the first English-language book to consider the cultural and religious responses to the second law of thermodynamics, from around 1860 to 1920. According to the second law of thermodynamics, as formulated by the German physicist Rudolf Clausius, the entropy of any closed system...... will inevitably increase in time, meaning that the system will decay and eventually end in a dead state of equilibrium. Application of the law to the entire universe, first proposed in the 1850s, led to the prediction of a future 'heat death', where all life has ceased and all organization dissolved. In the late...

  14. Scanning photocurrent microscopy reveals electron-hole asymmetry in ionic liquid-gated WS{sub 2} transistors

    Energy Technology Data Exchange (ETDEWEB)

    Ubrig, Nicolas, E-mail: nicolas.ubrig@unige.ch; Kuzmenko, Alexey B., E-mail: Alexey.Kuzmenko@unige.ch [DPMC, Université de Genève, 24 quai Ernest Ansermet, CH-1211 Geneva (Switzerland); Jo, Sanghyun; Morpurgo, Alberto F. [DPMC, Université de Genève, 24 quai Ernest Ansermet, CH-1211 Geneva (Switzerland); GAP, Université de Genève, 24 quai Ernest Ansermet, CH-1211 Geneva (Switzerland); Berger, Helmuth [Institut de Physique de la Matière Condendée, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland)

    2014-04-28

    We perform scanning photocurrent microscopy on WS{sub 2} ionic liquid-gated field effect transistors exhibiting high-quality ambipolar transport. By properly biasing the gate electrode, we can invert the sign of the photocurrent showing that the minority photocarriers are either electrons or holes. Both in the electron- and hole-doping regimes the photocurrent decays exponentially as a function of the distance between the illumination spot and the nearest contact, in agreement with a two-terminal Schottky-barrier device model. This allows us to compare the value and the doping dependence of the diffusion length of the minority electrons and holes on a same sample. Interestingly, the diffusion length of the minority carriers is several times larger in the hole accumulation regime than in the electron accumulation regime, pointing out an electron-hole asymmetry in WS{sub 2}.

  15. Interaction-enhanced electron-hole and valley asymmetries in the lowest Landau level of ABA-stacked trilayer graphene

    Science.gov (United States)

    Shizuya, K.

    2014-04-01

    In a magnetic field, graphene trilayers support a special multiplet of 12 zero(-energy)-mode Landau levels with a threefold degeneracy in Landau orbitals. A close look is made into such zero-mode levels in ABA-stacked trilayers, with the Coulomb interaction taken into account. It turns out that the zero-mode Landau levels of ABA trilayers are greatly afflicted with electron-hole and valley asymmetries, which come from general hopping parameters and which are enhanced by the Coulomb interaction and the associated vacuum effect, the orbital Lamb shift, that lifts the zero-mode degeneracy. These asymmetries substantially affect the way the zero-mode levels evolve with filling via Coulomb interactions, and its consequences are discussed in the light of experiments.

  16. The ion pairs and superconducting bosons

    OpenAIRE

    Minasyan, V. N.

    2008-01-01

    First, it is shown that the creation of the spinless ion pairs in the lattice, which are hold by the binding with neighbor ion pairs together regarded as covalent. These ion pairs are created by the repulsive potential interaction of two ions which is bound as linear oscillator. The repulsive S-wave scattering between ion pairs and electrons is transformed to the attractive effective interaction between electrons which leads to a creation of electron pairs by a binding energy depending on the...

  17. Polaron pair mediated triplet generation in polymer/fullerene blends

    KAUST Repository

    Dimitrov, Stoichko D.

    2015-03-04

    Electron spin is a key consideration for the function of organic semiconductors in light-emitting diodes and solar cells, as well as spintronic applications relying on organic magnetoresistance. A mechanism for triplet excited state generation in such systems is by recombination of electron-hole pairs. However, the exact charge recombination mechanism, whether geminate or nongeminate and whether it involves spin-state mixing is not well understood. In this work, the dynamics of free charge separation competing with recombination to polymer triplet states is studied in two closely related polymer-fullerene blends with differing polymer fluorination and photovoltaic performance. Using time-resolved laser spectroscopic techniques and quantum chemical calculations, we show that lower charge separation in the fluorinated system is associated with the formation of bound electron-hole pairs, which undergo spin-state mixing on the nanosecond timescale and subsequent geminate recombination to triplet excitons. We find that these bound electron-hole pairs can be dissociated by electric fields.

  18. Strong electron-hole symmetric Rashba spin-orbit coupling in graphene/monolayer transition metal dichalcogenide heterostructures

    Science.gov (United States)

    Yang, Bowen; Lohmann, Mark; Barroso, David; Liao, Ingrid; Lin, Zhisheng; Liu, Yawen; Bartels, Ludwig; Watanabe, Kenji; Taniguchi, Takashi; Shi, Jing

    2017-07-01

    Despite its extremely weak intrinsic spin-orbit coupling (SOC), graphene has been shown to acquire considerable SOC by proximity coupling with exfoliated transition metal dichalcogenides (TMDs). Here we demonstrate strong induced Rashba SOC in graphene that is proximity coupled to a monolayer TMD film, Mo S2 or WS e2 , grown by chemical-vapor deposition with drastically different Fermi level positions. Graphene/TMD heterostructures are fabricated with a pickup-transfer technique utilizing hexagonal boron nitride, which serves as a flat template to promote intimate contact and therefore a strong interfacial interaction between TMD and graphene as evidenced by quenching of the TMD photoluminescence. We observe strong induced graphene SOC that manifests itself in a pronounced weak-antilocalization (WAL) effect in the graphene magnetoconductance. The spin-relaxation rate extracted from the WAL analysis varies linearly with the momentum scattering time and is independent of the carrier type. This indicates a dominantly Dyakonov-Perel spin-relaxation mechanism caused by the induced Rashba SOC. Our analysis yields a Rashba SOC energy of ˜1.5 meV in graphene/WS e2 and ˜0.9 meV in graphene/Mo S2 . The nearly electron-hole symmetric nature of the induced Rashba SOC provides a clue to possible underlying SOC mechanisms.

  19. Assessment of pseudo-bilayer structures in the heterogate germanium electron-hole bilayer tunnel field-effect transistor

    Energy Technology Data Exchange (ETDEWEB)

    Padilla, J. L., E-mail: jose.padilladelatorre@epfl.ch; Alper, C.; Ionescu, A. M. [Nanoelectronic Devices Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015 (Switzerland); Medina-Bailón, C.; Gámiz, F. [Departamento de Electrónica y Tecnología de los Computadores, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada (Spain)

    2015-06-29

    We investigate the effect of pseudo-bilayer configurations at low operating voltages (≤0.5 V) in the heterogate germanium electron-hole bilayer tunnel field-effect transistor (HG-EHBTFET) compared to the traditional bilayer structures of EHBTFETs arising from semiclassical simulations where the inversion layers for electrons and holes featured very symmetric profiles with similar concentration levels at the ON-state. Pseudo-bilayer layouts are attained by inducing a certain asymmetry between the top and the bottom gates so that even though the hole inversion layer is formed at the bottom of the channel, the top gate voltage remains below the required value to trigger the formation of the inversion layer for electrons. Resulting benefits from this setup are improved electrostatic control on the channel, enhanced gate-to-gate efficiency, and higher I{sub ON} levels. Furthermore, pseudo-bilayer configurations alleviate the difficulties derived from confining very high opposite carrier concentrations in very thin structures.

  20. Exploring various sources of electron-hole screening in CH3NH3PbI3 solar cell materials using the Bethe-Salpeter equation

    Science.gov (United States)

    Leveillee, Joshua; Schleife, Andre

    Hybrid organic-inorganic perovskite materials have emerged as promising next generation thin-film solar cells. While many working devices have been developed, the weak electron-hole interaction and low exciton binding energy have not been fully explained. Methods beyond ground-state calculations are required to fully understand the excited state properties of these materials. In this work, the excitonic spectrum of CH3NH3PbI3 is simulated using the Bethe-Salpeter Equation. We describe contributions to dielectric screening, such as electronic, free-carrier, lattice, and polaron, through the use of model dielectric functions for the electron-hole Coulomb interaction. The calculated optical properties are directly compared, qualitatively and quantitatively, to experimental results. We find that the contributions of lattice and free carrier screening are highly influential on the optical spectrum. Supported by National Science Foundation Research Grant CBET-1437230 and National Center for Super Computing Applications (Blue Waters Super Computer) at UIUC.

  1. Amplification of Cooper pair splitting current in a graphene-based Cooper pair beam splitter geometry

    Science.gov (United States)

    Islam, SK Firoz; Saha, Arijit

    2017-09-01

    Motivated by the recent experiments [Scientific Reports 6, 23051 (2016), 10.1038/srep23051; Phys. Rev. Lett. 114, 096602 (2015), 10.1103/PhysRevLett.114.096602], we theoretically investigate Cooper pair splitting current in a graphene-based Cooper pair beam splitter geometry. By considering the graphene-based superconductor as an entangler device, instead of normal [two-dimensional (2D)] BCS superconductor, we show that the Cooper pair splitting current mediated by the crossed Andreev process is amplified compared to its normal superconductor counterpart. This amplification is attributed to the strong suppression of the local normal Andreev reflection process (arising from the Cooper pair splitting) from the graphene-based superconductor to lead via the same quantum dot, in comparison to the usual 2D superconductor. Due to the vanishing density of states at the Dirac point of undoped graphene, a doped graphene-based superconductor is considered here and it is observed that Cooper pair splitting current is very insensitive to the doping level in comparison to the usual 2D superconductor. The transport process of nonlocal spin-entangled electrons also depends on the type of pairing, i.e., whether the electron-hole pairing is onsite, intersublattice or the combination of both. The intersublattice pairing of graphene causes the maximum nonlocal Cooper pair splitting current, whereas the presence of both pairings reduces the Cooper pair splitting current.

  2. Cloning Creationism in Turkey.

    Science.gov (United States)

    Edis, Taner

    1999-01-01

    Defines how political balances and changes in Turkey effect creation-evolution relation. Describes the influences of Bilim Arastirma Vakfi (BAV) on these changes, which are directly targeted to public education, and discusses the content of creationism. Questions why Islamic creationism is a copy of that of the Institute for Creation Research…

  3. Enhanced photocatalytic activity of α-Bi2O3 with high electron-hole mobility by codoping approach: A first-principles study

    Science.gov (United States)

    Li, Yujie; Yang, Fan; Yu, Ying

    2015-12-01

    To improve the photocatalytic activity of narrow-gap material Bi2O3, efforts need be made to lower the electron-hole recombination rate and widen the response range of visible light. Understanding the related mechanism is vital, which may lead to high electron-hole mobility and suitable band edge. In this paper we have studied the atomic and electronic structure of single metallic atom (Ag, Cu, Pb, Pd, Sn)-doped and nitrogen (N)-metal codoped Bi2O3 with α phase by first principles calculations. The calculation results firstly show that new impurity states appeared in band gap of α-Bi2O3 after single metal doping, especially for the doping of Cu, Ag and Pb, which showed shallow acceptor levels for α-Bi2O3. And the formation energy analysis indicates that Cu doped system was easier to be formed than other doped systems. All of those calculated properties are helpful to enhance the photocatalytic property of α-Bi2O3, which agrees well with experimental results. Interestingly, for anion atom N together with metallic atom (Ag, Cu, Pb, Pd, Sn) codoped α-Bi2O3 systems, it is found that N-2p state had impact on the electronic structure. Holes were demonstrated to be more delocalized in (Cu + N) codoped α-Bi2O3 system, which was responsible for high mobility of holes, then lowering the electron-hole recombination, and finally improving the photocatalytic performance of Bi2O3 significantly.

  4. Direct luminescence evidence for the degenerate electron-hole plasma formation in A/sup II/B/sup VI/ semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Brodin, M.S.; Bandura, V.M.; Matsko, M.G. (AN Ukrainskoj SSR, Kiev. Inst. Fiziki)

    1983-09-01

    The emission spectra of ZnTe and ZnSe crystals are investigated at T = 4.2 K at high excitation densities by a Coumarin 30 and 120 dye laser. It is shown that for excitation densities R/sub exc/ > 0.1 MW/cm/sup 2/ the emission spectrum of ZnTe exhibits the P-band due to inelastic exciton-exciton scattering. For R/sub exc/ > 6 MW/cm/sup 2/ the emission of a degenerate electron-hole plasma (EHP) is observed. These emission bands may be differentiated by scanning the exciting quanta energy in the short-wavelength tail region.

  5. A BiPO{sub 4}/BiOCl heterojunction photocatalyst with enhanced electron-hole separation and excellent photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Duo, Fangfang; Wang, Yawen; Mao, Xiaoming; Zhang, Xiaochao; Wang, Yunfang; Fan, Caimei, E-mail: fancm@163.com

    2015-06-15

    Highlights: • BiPO{sub 4}/BiOCl heterojunction photocatalyst was fabricated by the hydrothermal method. • The obtained products exhibited excellent photocatalytic activity on MO degradation. • The formed p–n heterojunction of BiPO{sub 4}/BiOCl enhanced the electron-hole separation. - Abstract: The novel BiPO{sub 4}/BiOCl heterojunction composites were successfully fabricated by a facile one-step hydrothermal method. The XRD, SEM, TEM, UV–vis DRS, transient photocurrent and EIS measurements were employed to characterize the phase structures, morphologies, optical properties, and electron–hole separation effect of the photocatalysts. BiPO{sub 4}/BiOCl composites exhibited much higher photocatalytic activity for the methyl orange (MO) degradation than single BiOCl and BiPO{sub 4} under simulated sunlight irradiation. Moreover, the stability test for the optimum synergetic molar ratio of BiPO{sub 4}/BiOCl composites indicated that the synthetic p-n heterojunction BiPO{sub 4}/BiOCl photocatalyst had the gratifying reutilization after five cycles. The results of transient photocurrent measurements and EIS demonstrated that the large enhancement of photocatalytic activity could be mainly ascribed to the surface junction of BiPO{sub 4}/BiOCl composite which can effectively improve electron-hole separation speed during photocatalytic process.

  6. First-principles investigations of electron-hole inclusion effects on optoelectronic properties of Bi2Te3, a topological insulator for broadband photodetector

    Science.gov (United States)

    Lawal, Abdullahi; Shaari, A.; Ahmed, R.; Jarkoni, Norshila

    2017-09-01

    Bismuth telluride (Bi2Te3), a layered compound with narrow band gap has been potentially reported for thermoelectric. However, strong light interaction of Bi2Te3 is an exciting feature to emerge it as a promising candidate for optoelectronic applications within broadband wavelengths. In this study, we investigate structural, electronic and optical properties of Bi2Te3 topological insulator using combination of density functional theory (DFT) and many-body perturbation theory (MBPT) approach. With the inclusion of van der Waals (vdW) correction in addition to PBE, the lattice parameters and interlayer distance are in good agreement with experimental results. Furthermore, for the precise prediction of fundamental band gap, we go beyond DFT and calculated band structure using one-shot GW approach. Interestingly, our calculated quasiparticle (QP) band gap, Eg of 0.169 eV, is in good agreement with experimental measurements. Taken into account the effects of electron-hole interaction by solving Bethe-Salpeter equation, the calculated optical properties, namely, imaginary and real parts of complex dielectric function, absorption coefficient, refractive index, reflectivity, extinction coefficient, electron energy loss function and optical conductivity all are in better agreement with available experimental results. Consistencies of our findings with experimental data validate the effectiveness of electron-hole interaction for theoretical investigation of optical properties.

  7. Creationism in Europe

    DEFF Research Database (Denmark)

    For decades, the creationist movement was primarily situated in the United States. Then, in the 1970s, American creationists found their ideas welcomed abroad, first in Australia and New Zealand, then in Korea, India, South Africa, Brazil, and elsewhere—including Europe, where creationism plays...... an expanding role in public debates about science policy and school curricula. In this, the first comprehensive history of creationism in Europe, leading historians, philosophers, and scientists narrate the rise of—and response to—scientific creationism, creation science, intelligent design, and organized...... antievolutionism in countries and religions throughout Europe. Providing a unique map of creationism in Europe, the authors chart the surprising history of creationist activities and strategies there. Over the past forty years, creationism has spread swiftly among European Catholics, Protestants, Jews, Hindus...

  8. Photon pair generation and manipulation in an integrated silicon chip

    NARCIS (Netherlands)

    Bonneau, D.; Silverstone, J.W.; Hadfield, R.H.; Zwiller, V.; Ohira, K.; Suzuki, N.; Yoshida, H.; Iizuka, N.; Ezaki, M.; Rarity, J.G.; O'Brien, J.L.; Thompson, M.G.

    2013-01-01

    Quantum photonics is a promising technology for implementing quantum information tasks. We demonstrate integration of multiple photon pair sources together with a circuit enabling creation and manipulation of photon pairs in a monolithic silicon-on-insulator chip.

  9. Reconciling Evolution and Creation.

    Science.gov (United States)

    Tax, Sol

    1983-01-01

    Proposes a way to reconcile evolution with creationism by hypothesizing that the universe was created when the scientific evidence shows, speculating that this was when God began the series of creations described in Genesis, and assuming that God gave humans intelligence to uncover the methods by which he ordained scientific evolution. (Author/MJL)

  10. Co-Creation

    DEFF Research Database (Denmark)

    Degnegaard, Rex

    2012-01-01

    Co-creation as a concept has won terrain over the past 10 years. In practice as well as in literature, co-creation is climbing the agenda in relation to contemporary opportunities and challenges within management, organization development, and change initiatives. However, there Is very little...

  11. Co-Creation

    DEFF Research Database (Denmark)

    Degnegaard, Rex

    Co-creation as a concept has won terrain over the past 10 years. In practice as well as in literature, co-creation is climbing the agenda in relation to contemporary opportunities and challenges within management, organization development, and change initiatives. However, there Is very little...

  12. Structural transformations in silicon under exposure by femtosecond laser pulse: role of electron-hole plasma and phonon-phonon anharmonism

    CERN Document Server

    Kudryashov, S I

    2002-01-01

    It is experimentally shown for the first time that by the effect of the feed-up laser pulse of 100 fs duration on the silicon target the consecutive structural transitions of the substance into the new crystalline and liquid metallic phase occur both during the laser pulse feed-up and after 0.1-10 sup 3 ps, depending on the material excitation conditions. The thresholds of the observed structural transitions are determined and the phonon nodes, responsible for therefore, are identified. The structural transitions dynamics in the silicon by the 01.-10 sup 3 ps times is described within the frames of the model of the phonon modes instability, originating due to the plasma electron-hole effect and also due to the intra- and intermode phonon-phonon anharmonic interactions

  13. Design and Analysis of CMOS-Compatible III-V Compound Electron-Hole Bilayer Tunneling Field-Effect Transistor for Ultra-Low-Power Applications.

    Science.gov (United States)

    Kim, Sung Yoon; Seo, Jae Hwa; Yoon, Young Jun; Lee, Ho-Young; Lee, Seong Min; Cho, Seongjae; Kang, In Man

    2015-10-01

    In this work, we design and analyze complementary metal-oxide-semiconductor (CMOS)-compatible III-V compound electron-hole bilayer (EHB) tunneling field-effect transistors (TFETs) by using two-dimensional (2D) technology computer-aided design (TCAD) simulations. A recently proposed EHB TFET exploits a bias-induced band-to-band tunneling (BTBT) across the electron-hole bilayer by an electric field from the top and bottom gates. This is in contrast to conventional planar p(+)-p(-)-n TFETs, which utilize BTBT across the source-to-channel junction. We applied III-V compound semiconductor materials to the EHB TFETs in order to enhance the current drivability and switching performance. Devices based on various compound semiconductor materials have been designed and analyzed in terms of their primary DC characteristics. In addition, the operational principles were validated by close examination of the electron concentrations and energy-band diagrams under various operation conditions. The simulation results of the optimally designed In0.533Ga0.47As EHB TFET show outstanding performance, with an on-state current (Ion) of 249.5 μA/μm, subthreshold swing (S) of 11.4 mV/dec, and threshold voltage (Vth) of 50 mV at VDS = 0.5 V. Based on the DC-optimized InGaAs EHB TFET, the CMOS inverter circuit was simulated in views of static and dynamic behaviors of the p-channel device with exchanges between top and bottom gates or between source and drain electrodes maintaining the device structure.

  14. Creationism in Europe

    DEFF Research Database (Denmark)

    For decades, the creationist movement was primarily situated in the United States. Then, in the 1970s, American creationists found their ideas welcomed abroad, first in Australia and New Zealand, then in Korea, India, South Africa, Brazil, and elsewhere—including Europe, where creationism plays...... the teaching of creationism as a scientific discipline on an equal footing with the theory of evolution." Creationism in Europe offers a discerning introduction to the cultural history of modern Europe, the variety of worldviews in Europe, and the interplay of science and religion in a global context...

  15. Creationism in Europe

    DEFF Research Database (Denmark)

    Hjermitslev, Hans Henrik; Kjærgaard, Peter C.; Blancke, Stefaan

    2013-01-01

    The purpose of our article is threefold. First, we present and discuss the extant literature on creationism in Europe (the “facts”). Within this section, we offer a review of the literature as well as an overview of the most remarkable developments and events recorded therein. Second, we indicate...... a sustained study of European creationism can contribute to other research domains such as the study of cultural evolution and the relation between science and religion....

  16. Magnetic field stabilized electron-hole liquid in indirect-band-gap A lxG a1 -xAs

    Science.gov (United States)

    Alberi, K.; Fluegel, B.; Crooker, S. A.; Mascarenhas, A.

    2016-02-01

    An electron-hole liquid (EHL), a condensed liquidlike phase of free electrons and holes in a semiconductor, presents a unique system for exploring quantum many-body phenomena. While the behavior of EHLs is generally understood, less attention has been devoted to systematically varying the onset of their formation and resulting properties. We report on an experimental approach to tune the conditions of formation and characteristics using a combination of low excitation densities and high magnetic fields up to 90 T. Demonstration of this approach was carried out in indirect-band-gap A l0.387G a0.613As . EHL droplets can be nucleated from one of two multiexciton complex states depending on the applied excitation density. Furthermore, the excitation density influences the carrier density of the EHL at high magnetic fields, where filling of successive Landau levels can be controlled. The ability to manipulate the formation pathway, temperature, and carrier density of the EHL phase under otherwise fixed experimental conditions makes our approach a powerful tool for studying condensed carrier phases in further detail.

  17. Creation of Auditing Knowledge:

    DEFF Research Database (Denmark)

    Liempd, Dennis van

    , and a too one-sided view on the creation of auditing knowledge. The purpose of this paper is to call for more (diverse) research in this area. Earlier calls have been few and far between, and have not resulted in a lot of research. Within the last two decades though, the auditing universe has changed so...... much that high-quality auditing research never has been needed more. By reviewing available literature challenges to the auditing profession are explored, and the creation of knowledge in general and auditing knowledge in particular are discussed with respect to methodological approaches and operative...

  18. Opposing Creationism: Scientists Organize.

    Science.gov (United States)

    Saladin, Kenneth S.

    1982-01-01

    Describes the response of the scientific community to creationist activism. A symposium entitled "Science and Belief" was held at the annual meeting of the American Association for the Advancement of Science to debate creationism. A network was organized to facilitate communication and political efficiency among anticreationist citizen…

  19. Path dependence and creation

    DEFF Research Database (Denmark)

    Garud, Raghu; Karnøe, Peter

    the place of agency in these theories that take history so seriously. In the end, they are as interested in path creation and destruction as they are in path dependence. This book is compiled of both theoretical and empirical writing. It shows relatively well-known industries such as the automobile...

  20. Architectural Creation of Light

    DEFF Research Database (Denmark)

    Bülow, Katja

    2015-01-01

    Bidraget "Architectural Creation of Light" indgår sammen med 108 andre bidrag i bogen "You Say Light, I Think Shadow". Bogens indhold undersøger: "Hvad er lys". I dette bidrag besvares spørgsmålet gennem iagttagelser af arkitektstuderendes undersøgelser af lyset i deres arbejdsmodeller i...

  1. Electron-ion coupling and ambipolar diffusion in dense electron-hole plasma in thin amorphous Si films studied by single-shot, pulse-width dependent ultrafast laser ablation

    Science.gov (United States)

    Danilov, Pavel; Ionin, Andrey; Khmelnitskii, Roman; Kiseleva, Irina; Kudryashov, Sergey; Mel'nik, Nikolay; Rudenko, Andrey; Smirnov, Nikita; Zayarny, Dmitry

    2017-12-01

    Single-shot ablation of amorphous silicon films of 50-, 100- and 150-nm thickness by laser pulses of variable (0.2-6 ps) widths demonstrates non-monotonous variation of ablation thresholds and characteristic ablation 1/e-radii with their minima at the 0.6-ps pulse-width and the following increase. For the shorter laser pulses the increased thresholds and enhanced transport can be related to fast ambipolar electron-hole plasma diffusion and other electronic energy losses in dense transient plasma prior its energy transfer to the ionic subsystem (electron-ion thermalization) at 0.6 ps, while for the longer laser pulses slower ambipolar diffusion in moderate-density electron-hole plasma, ionic heat conduction and other thermal losses may predominate.

  2. Hole pairs in a spin liquid: Influence of electrostatic hole-hole repulsion

    Science.gov (United States)

    Gazza, Claudio; Martins, George B.; Riera, José; Dagotto, Elbio

    1999-01-01

    The stability of hole bound states in the t-J model including short-range Coulomb interactions is analyzed using computational techniques on ladders with up to 2×30 sites. For a nearest-neighbor (NN) hole-hole repulsion, the two-holes bound state is surprisingly robust and breaks only when the repulsion is several times the exchange J. At ~10% hole doping the pairs break only for a NN repulsion as large as V~4J. Pair-pair correlations remain robust in the regime of hole binding. The results support electronic hole-pairing mechanisms on ladders based on holes moving in spin-liquid backgrounds. Implications in two dimensions are also presented. The need for better estimations of the range and strength of the Coulomb interaction in copper oxides is remarked.

  3. Creationism and intelligent design.

    Science.gov (United States)

    Pennock, Robert T

    2003-01-01

    Creationism, the rejection of evolution in favor of supernatural design, comes in many varieties besides the common young-earth Genesis version. Creationist attacks on science education have been evolving in the last few years through the alliance of different varieties. Instead of calls to teach "creation science," one now finds lobbying for "intelligent design" (ID). Guided by the Discovery Institute's "Wedge strategy," the ID movement aims to overturn evolution and what it sees as a pernicious materialist worldview and to renew a theistic foundation to Western culture, in which human beings are recognized as being created in the image of God. Common ID arguments involving scientific naturalism, "irreducible complexity," "complex specified information," and "icons of evolution," have been thoroughly examined and refuted. Nevertheless, from Kansas to Ohio to the U.S. Congress, ID continues lobbying to teach the controversy, and scientists need to be ready to defend good evolution education.

  4. Numerical Computation of Dynamical Schwinger-like Pair Production in Graphene

    Science.gov (United States)

    Fillion-Gourdeau, F.; Blain, P.; Gagnon, D.; Lefebvre, C.; Maclean, S.

    2017-03-01

    The density of electron-hole pairs produced in a graphene sample immersed in a homogeneous time-dependent electric field is evaluated. Because low energy charge carriers in graphene are described by relativistic quantum mechanics, the calculation is performed within the strong field quantum electrodynamics formalism, requiring a solution of the Dirac equation in momentum space. The equation is solved using a split-operator numerical scheme on parallel computers, allowing for the investigation of several field configurations. The strength of the method is illustrated by computing the electron momentum density generated from a realistic laser pulse model. We observe quantum interference patterns reminiscent of Landau-Zener-Stückelberg interferometry.

  5. Tracking the coherent generation of polaron pairs in conjugated polymers.

    Science.gov (United States)

    De Sio, Antonietta; Troiani, Filippo; Maiuri, Margherita; Réhault, Julien; Sommer, Ephraim; Lim, James; Huelga, Susana F; Plenio, Martin B; Rozzi, Carlo Andrea; Cerullo, Giulio; Molinari, Elisa; Lienau, Christoph

    2016-12-08

    The optical excitation of organic semiconductors not only generates charge-neutral electron-hole pairs (excitons), but also charge-separated polaron pairs with high yield. The microscopic mechanisms underlying this charge separation have been debated for many years. Here we use ultrafast two-dimensional electronic spectroscopy to study the dynamics of polaron pair formation in a prototypical polymer thin film on a sub-20-fs time scale. We observe multi-period peak oscillations persisting for up to about 1 ps as distinct signatures of vibronic quantum coherence at room temperature. The measured two-dimensional spectra show pronounced peak splittings revealing that the elementary optical excitations of this polymer are hybridized exciton-polaron-pairs, strongly coupled to a dominant underdamped vibrational mode. Coherent vibronic coupling induces ultrafast polaron pair formation, accelerates the charge separation dynamics and makes it insensitive to disorder. These findings open up new perspectives for tailoring light-to-current conversion in organic materials.

  6. Creation, Identity and Reflection

    Directory of Open Access Journals (Sweden)

    Alina Beatrice Cheşcă

    2015-05-01

    Full Text Available The paper “Creation, Identity and Reflection” approaches the identification in the “mirror” of reality with creation, in other words seeking the authors’ identity in the reflected images. Reflection means attempting to find oneself, the mirror being the main principle of creation. Many characters become interesting only when they step into the world beyond the mirror, when their faces are doubled by the other self or when their selves are returned by other characters. The narcissistic concept of the mirror, i.e. the reflection in the mirror and the representation of the mirror itself, is a recurrent one in literature, but the reflection of the self which is not the self (as it is a reflection does not necessarily appear in a mirror or in a photograph or portrait. Sometimes, the not-self is returned to the self by another person or character. As far as Oscar Wilde’s theories are concerned, the main idea is that people are interesting for their masks, not for their inner nature. What Wilde calls “inner nature” is the characters’ un-reflected self and the mask is the reflection, the self in the mirror. Some characters’ relationships develop within a fiction that they dramatically try to preserve and protect with the risk of suffering. They refuse to take off the masks which define them in the others’ minds and hearts; the narcissistic individuals (both artists and characters seek and love their own image which they project upon facts, thus creating a fictive realm.

  7. Path dependence and creation

    DEFF Research Database (Denmark)

    Garud, Raghu; Karnøe, Peter

    the place of agency in these theories that take history so seriously. In the end, they are as interested in path creation and destruction as they are in path dependence. This book is compiled of both theoretical and empirical writing. It shows relatively well-known industries such as the automobile......, biotechnology and semi-conductor industries in a new light. It also invites the reader to learn more about medical practices, wind power, lasers and synthesizers. Primarily for academicians, researchers and PhD students in fields related to technology management, this book is a research-oriented textbook...

  8. Disruptive Co-Creation?

    DEFF Research Database (Denmark)

    Butler, Ivan; Christensen, David

    set up to foster innovative partnerships between civil society organizations, businesses and academia with the objective of supporting disruptive business model innovation in co-creation processes across these sectors. This paper delves into state-of-the-art concerning literature pertinent......Faced with constant changes in the marketplace and increasing pressure to adapt to e.g. recessive and saturated conditions, businesses in industrialized countries have the option to pursue opportunities in emerging markets. In the poorest of developing countries, there is a proposition of high......-payoff, albeit high-risk opportunities for sustainable business models that address poverty alleviation. However, many businesses exhibit hesitation and wariness before giving serious consideration toward entering markets in e.g. Sub-Saharan Africa. In addressing this, the initiative access2innovation has been...

  9. Life after stoma creation

    DEFF Research Database (Denmark)

    Danielsen, Anne Kjærgaard

    2013-01-01

    , as well as an alteration in the bodily design. Research in the field may provide additional information about central elements when adapting to life with a stoma. There are currently no studies that adequately focus on the relationship between health-related quality of life and stoma construction...... in a Danish context, neither for temporary or permanent construction, nor in relation to the importance of stoma handling. Purpose: The overall objective of the study was to investigate health-related quality of life related to stoma creation and patient education. Methodologically, the project......: Impact on everyday life and Educational Needs. The study included 15 participants who were interviewed in groups related to whether they were treated for cancer or non-cancer. The results showed that participants often experienced the stoma as a taboo, and emotions related to stigma were identified...

  10. The Co-creation Continuum

    DEFF Research Database (Denmark)

    Ind, Nicholas; Iglesias, Oriol; Markovic, Stefan

    2017-01-01

    Co-creation can open up a brand to the outside world and help it to generate relevant innovations. However, there is scarce empirical evidence as to how managers actually use co-creation to connect with customers and other stakeholders and build enduring innovation-oriented relationships with them....... To better understand this, as well as the assumptions of managers and the barriers they encounter in realizing the potential of co-creation, the authors have conducted 20 semi-structured interviews with managers that have led co-creation initiatives for 20 brands. This research finds diverse views of co-creation...... - from tactical market research tool to strategic collaborative innovation method, and shows that brands can be positioned along a continuum between these two polarities. This article also presents the implications for those that want to seize the potential of co-creation....

  11. The Scientific Creationism

    Directory of Open Access Journals (Sweden)

    Raluca Marinela SILAGHI

    2016-07-01

    Full Text Available The subject of the present paper is the analysis of the origin of the universe, time, life, mankind and of the geological column, from the perspective of the creationist model, and through comparisons with the evolutionist model. The creationist model, as opposed to the evolutionist one, affirms that the universe and also the mankind were created directly and perfectly by the Creator. Since the very beginning, man has been endowed with a complete biological development, with the capacity to think, with freedom of choice, with certain abilities of survival, of using the land and its resources in conformity with the purpose intended by the Creator and with the ability to transmit ideas in written form over generations. The geological column has been formed during a single age, through a hydraulic catastrophic event (that corresponds to the Archaeozoic Era that has lead to the storing of sediments (Proterozoic; generated by the disintegration of mountains and rocks and to the creation of all the fossil deposits, from the death of plants, animals and human beings trapped by the sediments.

  12. Life after stoma creation.

    Science.gov (United States)

    Danielsen, Anne Kjærgaard

    2013-10-01

    Stoma creation is a surgical operation where the surgeon makes an artificial opening on the abdomen from where the bowel is taken out. It is a radical treatment with permanent physical signs of bodily change. In general, it leads to loss of a central and personal physical function, as well as an alteration in the bodily design. Research in the field may provide additional information about central elements when adapting to life with a stoma. There are currently no studies that adequately focus on the relationship between health-related quality of life and stoma construction in a Danish context, neither for temporary or permanent construction, nor in relation to the importance of stoma handling. The overall objective of the study was to investigate health-related quality of life related to stoma creation and patient education. Methodologically, the project was implemented as a mixed methods study in which qualitative interview studies and two systematic literature reviews identified interventions, which were subsequently tested in a clinical case/control study. Finally the case/control study was made subject to an economic analysis. The project is based on 6 papers reporting the results. ARTICLE 1: Impact of a temporary stoma on patients everyday-lives: feelings of uncertainty while waiting for closure of the stoma. The study included 7 participants who were interviewed in focus groups. The results indicated that patients experienced a high degree of uncertainty in connection with the stoma being temporary. At the same time, participants had a strong need to control both their physical appearance and their changed bodily functions. Participants opted for education programs involving teachers with a stoma. ARTICLE 2: Learning to live with a Permanent Intestinal Ostomy: Impact on everyday life and Educational Needs. The study included 15 participants who were interviewed in groups related to whether they were treated for cancer or non-cancer. The results showed that

  13. Interpretation and creationism.

    Science.gov (United States)

    Ahumada, J L

    1994-08-01

    This paper is an attempt to raise questions about certain underlying and implicit assumptions in some hermeneutic and narrative approaches to psychoanalysis. Starting from the view that Freud saw interpretation in the clinical setting as an attempt to unveil the analysand's psychic reality, it is argued that he envisaged that psychoanalysis aims to interpret what is real in the analysand's inner world--an empirical line of thought underpinned by the idea of analytic neutrality and an emphasis on the analysand's capacity to judge reality. By contrast, the tendency within the hermeneutic-narrative tradition is to demote psychic reality in favour of an emphasis on the analyst's capacity to interpret in order to help his analysand construct meaning. This approach may be said to put the analyst's words in the place of those of the Creator; in other words, it amounts to a 'verbal creationism', which the author argues is rooted in the idealistic philosophy of Hegel, Vico and Descartes and, further back, can be traced to the Book of Genesis--a conclusion causing the author to express some reservations.

  14. Job Creation and Job Types

    DEFF Research Database (Denmark)

    Kuhn, Johan M.; Malchow-Møller, Nikolaj; Sørensen, Anders

    We extend earlier analyses of the job creation of start-ups vs. established firms by taking into consideration the educational content of the jobs created and destroyed. We define educationspecific measures of job creation and job destruction at the firm level, and we use these to construct a mea...

  15. Creation, the eschaton, and bioethics.

    Science.gov (United States)

    Moraczewski, A S

    1979-09-01

    The Christian's role in renewing the universe is to discover the true name of God's creation and to use technology as a serious enterprise of co-creation. Guided by a bioethics based on Gospel values, the Christian healer brings the eschaton closer to realization.

  16. Job Creation and Job Types

    DEFF Research Database (Denmark)

    Kuhn, Johan Moritz; Malchow-Møller, Nikolaj; Sørensen, Anders

    2016-01-01

    We extend earlier analyses of the job creation of start-ups versus established firms by considering the educational content of the jobs created and destroyed. We define education-specific measures of job creation and job destruction at the firm level, and we use these measures to construct...... a measure of “surplus job creation”, defined as jobs created on top of any simultaneous destruction of similar jobs in incumbent firms in the same region and industry. Using Danish employer-employee data from 2002–2007 that identify the start-ups and that cover almost the entire private sector......, these measures allow us to provide a more nuanced assessment of the role of entrepreneurial firms in the job-creation process than in previous studies. Our findings show that although start-ups are responsible for the entire overall net job creation, incumbents account for more than one-third of net job creation...

  17. Value Creation in International Business

    DEFF Research Database (Denmark)

    Vedel, Mette; Servais, Per

    2017-01-01

    The edited collection brings into focus the meanings, interpretations and the process of value creation in international business. Exploring value creation in the context of emerging and developed economies, Volume 2 takes the perspective of small and medium sized enterprises and examines various...... approaches to value creation in the process of firm internationalization. Providing theoretical and practical insights, the authors open an intellectual debate into what value is, and how it is created through the internationalization activities of firms. Value Creation in International Business...... is a pioneering two volume work intended to provoke theoretical and empirical development in International Business research. Moreover, it is intended as a bridge between concepts derived from general business firm-level research agendas such as value creation and business model, and internationalization...

  18. Value Creation in International Business

    DEFF Research Database (Denmark)

    The edited collection brings into focus the meanings, interpretations and the process of value creation in international business. Exploring value creation in the context of emerging and developed economies, Volume 2 takes the perspective of small and medium sized enterprises and examines various...... approaches to value creation in the process of firm internationalization. Providing theoretical and practical insights, the authors open an intellectual debate into what value is, and how it is created through the internationalization activities of firms. Value Creation in International Business...... is a pioneering two volume work intended to provoke theoretical and empirical development in International Business research. Moreover, it is intended as a bridge between concepts derived from general business firm-level research agendas such as value creation and business model, and internationalization...

  19. Excitons in core-only, core-shell and core-crown CdSe nanoplatelets: Interplay between in-plane electron-hole correlation, spatial confinement, and dielectric confinement

    Science.gov (United States)

    Rajadell, Fernando; Climente, Juan I.; Planelles, Josep

    2017-07-01

    Using semianalytical models we calculate the energy, effective Bohr radius, and radiative lifetime of neutral excitons confined in CdSe colloidal nanoplatelets (NPLs). The excitonic properties are largely governed by the electron-hole in-plane correlation, which in NPLs is enhanced by the quasi-two-dimensional motion and the dielectric mismatch with the organic environment. In NPLs with lateral size L ≳20 nm the exciton behavior is essentially that in a quantum well, with super-radiance leading to exciton lifetimes of 1 ps or less, only limited by the NPL area. However, for L crown configurations. In the former, the strong vertical confinement limits separation of electrons and holes even for type-II band alignment. The exciton behavior is then similar to that in core-only NPL, albeit with weakened dielectric effects. In the latter, charge separation is also inefficient if band alignment is quasi-type-II (e.g., in CdSe/CdS), because electron-hole interaction drives both carriers into the core. However, it becomes very efficient for type-II alignment, for which we predict exciton lifetimes reaching microseconds.

  20. Dual origin of pairing in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Idini, A. [University of Jyvaskyla, Department of Physics (Finland); Potel, G. [Michigan State University, National Superconducting Cyclotron Laboratory (United States); Barranco, F. [Escuela Superior de Ingenieros, Universidad de Sevilla, Departamento de Fìsica Aplicada III (Spain); Vigezzi, E., E-mail: enrico.vigezzi@mi.infn.it [INFN Sezione di Milano (Italy); Broglia, R. A. [Università di Milano, Dipartimento di Fisica (Italy)

    2016-11-15

    The pairing correlations of the nucleus {sup 120}Sn are calculated by solving the Nambu–Gor’kov equations, including medium polarization effects resulting from the interweaving of quasiparticles, spin and density vibrations, taking into account, within the framework of nuclear field theory (NFT), processes leading to self-energy and vertex corrections and to the induced pairing interaction. From these results one can not only demonstrate the inevitability of the dual origin of pairing in nuclei, but also extract information which can be used at profit to quantitatively disentangle the contributions to the pairing gap Δ arising from the bare and from the induced pairing interaction. The first is the strong {sup 1}S{sub 0} short-range NN potential resulting from meson exchange between nucleons moving in time reversal states within an energy range of hundreds of MeV from the Fermi energy. The second results from the exchange of vibrational modes between nucleons moving within few MeV from the Fermi energy. Short- (v{sub p}{sup bare}) and long-range (v{sub p}{sup ind}) pairing interactions contribute essentially equally to nuclear Cooper pair stability. That is to the breaking of gauge invariance in open-shell superfluid nuclei and thus to the order parameter, namely to the ground state expectation value of the pair creation operator. In other words, to the emergent property of generalized rigidity in gauge space, and associated rotational bands and Cooper pair tunneling between members of these bands.

  1. Co-Creation in Distributed Value Creation Systems and Networks

    DEFF Research Database (Denmark)

    Bang, Anne Louise; Christensen, Poul Rind

    2013-01-01

    Design and management are not performed in organizational isolation, but rather in distributed networks of actors and activities. In this contribution co-creation and relationship management are combined in a network perspective.......Design and management are not performed in organizational isolation, but rather in distributed networks of actors and activities. In this contribution co-creation and relationship management are combined in a network perspective....

  2. Entrepreneuring as Organisation-Creation

    DEFF Research Database (Denmark)

    Hjorth, Daniel

    2014-01-01

    This chapter aims at making a contribution to the study of entrepreneurship and creativity by developing a processual conceptualisation of a form of entrepreneurial creativity called entrepreneuring or organisation-creation. Such a processual conceptualisation of entrepreneuring will answer...

  3. Quantum delocalization in photon-pair generation

    Science.gov (United States)

    Forbes, Kayn A.; Ford, Jack S.; Jones, Garth A.; Andrews, David L.

    2017-08-01

    The generation of correlated photon pairs is a key to the production of entangled quantum states, which have a variety of applications within the area of quantum information. In spontaneous parametric down-conversion—the primary method of generating correlated photon pairs—the associated photon annihilation and creation events are generally thought of as being colocated: The correlated pair of photons is localized with regards to the pump photon and its positional origin. A detailed quantum electrodynamical analysis highlights a mechanism exhibiting the possibility of a delocalized origin for paired output photons: The spatial extent of the region from which the pair is generated can be much larger than previously thought. The theory of both localized and nonlocalized degenerate down-conversion is presented, followed by a quantitative analysis using discrete-volume computational methods. The results may have significant implications for quantum information and imaging applications, and the design of nonlinear optical metamaterials.

  4. 'Ethos' Enabling Organisational Knowledge Creation

    Science.gov (United States)

    Matsudaira, Yoshito

    This paper examines knowledge creation in relation to improvements on the production line in the manufacturing department of Nissan Motor Company and aims to clarify embodied knowledge observed in the actions of organisational members who enable knowledge creation will be clarified. For that purpose, this study adopts an approach that adds a first, second, and third-person's viewpoint to the theory of knowledge creation. Embodied knowledge, observed in the actions of organisational members who enable knowledge creation, is the continued practice of 'ethos' (in Greek) founded in Nissan Production Way as an ethical basis. Ethos is knowledge (intangible) assets for knowledge creating companies. Substantiated analysis classifies ethos into three categories: the individual, team and organisation. This indicates the precise actions of the organisational members in each category during the knowledge creation process. This research will be successful in its role of showing the indispensability of ethos - the new concept of knowledge assets, which enables knowledge creation -for future knowledge-based management in the knowledge society.

  5. Color, light, and altruistic creation

    Science.gov (United States)

    Charnay, Yves

    2002-06-01

    It seems necessary to me to combine a certain technical inventivity with plastic creation, a particular poetry arises from this relation. The sources of inspiration for works, especially works in which color plays a pre-eminent role, do not only come from nature. The fantasy of the creators evolves and changes thanks to discoveries and technological inventions. My work as a painter has made me particularly sensitive to the diversity of the plastic writings in general and to the chromatic writings in particular. (1) Environmental creation imposes a renewal of the means of creation. Conducting experimental works, I study the particularities of light, mainly its incidence on materials (transmission, reflection, colors, textures, etc.) and its mobility. These works are a source of inspiration for my architectural works and nurture my lectures at the Ecole Nationale Superieure des Arts Decoratifs (National College of Decorative Arts). Environmental creation also imposes some qualities on the artist since he, whether he serves a social entity or a person, serves the whole collectivity. Environmental creation has to be envisaged as an altruistic approach.

  6. Ludic Educational Game Creation Tool

    DEFF Research Database (Denmark)

    Vidakis, Nikolaos; Syntychakis, Efthimios; Kalafatis, Konstantinos

    2015-01-01

    creation tool features a web editor, where the game narrative can be manipulated, according to specific needs. Moreover, this tool is applied for creating an educational game according to a reference scenario namely teaching schoolers road safety. A ludic approach is used both in game creation and play...... for teaching road safety, by employing ludic interfaces for both the game creator and the game player, as well as ludic game design........ Helping children staying safe and preventing serious injury on the roads is crucial. In this context, this work presents an augmented version of the IOLAOS architecture including an enhanced game creation tool and a new multimodality module. In addition presents a case study for creating educational games...

  7. Knowledge Sharing is Knowledge Creation

    DEFF Research Database (Denmark)

    Greve, Linda

    2015-01-01

    Knowledge sharing and knowledge transfer are important to knowledge communication. However when groups of knowledge workers engage in knowledge communication activities, it easily turns into mere mechanical information processing despite other ambitions. This article relates literature of knowledge...... communication and knowledge creation to an intervention study in a large Danish food production company. For some time a specific group of employees uttered a wish for knowledge sharing, but it never really happened. The group was observed and submitted to metaphor analysis as well as analysis of co......-creation strategies. Confronted with the results, the group completely altered their approach to knowledge sharing and let it become knowledge co-creation. The conclusions are, that knowledge is and can only be a diverse and differentiated concept, and that groups are able to embrace this complexity. Thus rather than...

  8. Concurrent Product & Supply Chain Creation

    DEFF Research Database (Denmark)

    Gubi, Ebbe

    .e. by creating Focused Supply Chains. At the same time, customer satisfaction can be increased. As a second means to achieving a better fit between product and supply chain, the firm can deploy Design for Logistics, the discipline of considering the supply chain during product creation. The thesis sets out...... and supply chains should be created concurrently and integrated. The concept of Concurrent Product & Supply Chain Creation is introduced, and the two main components Focused Supply Chains and Design For Logistics are explained and exemplified by use of Bang & Olufsen....

  9. Ecological ethics and creation faith

    Directory of Open Access Journals (Sweden)

    Ulrich Körtner

    2016-05-01

    Full Text Available Over past decades a concept of ecological ethics has taken root, which is often equated with environmental ethics. Church and theology have also responded to the environmental crisis. In the last third of the past century an intense discourse about the concerns and extent of a so called creation ethics was conducted. In connection with the question of a creation ethics, and the global responsibility of humans for the biosphere of our planet, the topic of creation has also gained new attention in dogmatics. In this way, ecology has also become a topic of systematic theology. The article focuses on the debate in the German speaking context. Occasionally, a quasi-religious elevation of ecology to the status of a doctrine of salvation is observable. Because theology always also has a function of critique of religion, it must also critically engage the sometimes open and sometimes hidden religious contents and claims of eco-ethical concepts. For this purpose, the first step of the present contribution is to more precisely determine the concepts of creation and nature. Thereafter, the problem of anthropocentrism is analysed. In a further step, the concept of sustainability is analysed. In conclusion, the main features of a responsibility-ethics model of ecological ethics are outlined.

  10. Juvenile Courts. Creation and development

    Directory of Open Access Journals (Sweden)

    Montserrat GONZÁLEZ FERNÁNDEZ

    2013-11-01

    Full Text Available This paper studies the creation of Juvenile or Children's Courts in Spain, analysing their reasons and aims, as well as the ethical and political connotations present on their way of acting. Their history and the one of the institutions that complement them is built from the legislation, writings and ideas of their promoters.

  11. Knowledge Creation in Constructivist Learning

    Science.gov (United States)

    Jaleel, Sajna; Verghis, Alie Molly

    2015-01-01

    In today's competitive global economy characterized by knowledge acquisition, the concept of knowledge management has become increasingly prevalent in academic and business practices. Knowledge creation is an important factor and remains a source of competitive advantage over knowledge management. Constructivism holds that learners learn actively…

  12. Facilitating Value Co-Creation

    DEFF Research Database (Denmark)

    Veith, Anne; Assaf, Albert; Josiassen, Alexander

    2013-01-01

    As a result of the current business environment, rise of technology, increasing globalization, etc., companies are therefore focusing on finding ways to differentiate themselves. Differentiation is therefore essential and co-creation is a core differentiation base. Vargo and Lusch (2004, 2006, 2008...

  13. Uprising of Creation in Education

    Science.gov (United States)

    Hatamleh, Habes Mohamed

    2015-01-01

    This research (Uprising of Creation in Education) aims at defining the importance of creativity in education, and its reflection on the elements of the educational process. Creativity is regarded an important element in the nations progress, which depends on the minds of their sons. Creativity became the language of the present age, after the…

  14. Evolution versus Creationism in Education

    Science.gov (United States)

    Apple, Michael W.

    2008-01-01

    As part of the continuing series of the Reviewing Policy section, this article examines some of the recent literature on the creation-evolution controversy. These controversies are placed within a larger analysis of the growth of authoritarian populist movements in the United States. The article then focuses attention on debates both over a number…

  15. Photon pair production in astrophysical transrelativistic plasmas

    Science.gov (United States)

    Stoeger, W. R.

    1977-01-01

    Photon pair-production processes in marginally relativistic (transrelativistic) accretion plasmas are investigated in both Planckian and non-Planckian cases. Pair production in a plasma with an equilibrium (Planck) spectrum is reviewed, and pair-concentration calculations are performed for three general non-Planckian situations most relevant to black-hole accretion scenarios: steady-state transrelativistic plasmas of relatively high density characterized by a pure bremsstrahlung spectrum, a comptonized bremsstrahlung spectrum, and an unsaturated Compton scattering spectrum. The results obtained indicate that for transrelativistic temperatures (600 million to 6 billion K) photon pair production is not generally a dominant process for a plasma with a pure bremsstrahlung spectrum, but becomes dominant for plasmas where comptonization is important. It is also shown that photon pair-creation processes in a transrelativistic bremsstrahlung-radiating plasma that is more than marginally optically thick to Compton scattering significantly alter the plasma's spectrum by forcing it to become black-body before it reaches relativistic temperatures. Pair production and instabilities in unsteady-state plasmas are briefly considered

  16. The fate of electron–hole pairs in polymer:fullerene blends for organic photovoltaics

    KAUST Repository

    Causa', Martina

    2016-09-02

    There has been long-standing debate on how free charges are generated in donor: acceptor blends that are used in organic solar cells, and which are generally comprised of a complex phase morphology, where intermixed and neat phases of the donor and acceptor material co-exist. Here we resolve this question, basing our conclusions on Stark effect spectroscopy data obtained in the absence and presence of externally applied electric fields. Reconciling opposing views found in literature, we unambiguously demonstrate that the fate of photogenerated electron-hole pairs-whether they will dissociate to free charges or geminately recombine-is determined at ultrafast times, despite the fact that their actual spatial separation can be much slower. Our insights are important to further develop rational approaches towards material design and processing of organic solar cells, assisting to realize their purported promise as lead-free, third-generation energy technology that can reach efficiencies over 10%.

  17. The Multiverse and Divine Creation

    Directory of Open Access Journals (Sweden)

    Michael Almeida

    2017-11-01

    Full Text Available I provide the account of divine creation found in multiverse theorists Donald Turner, Klaas Kraay, and Tim O’Connor. I show that the accounts Kraay and Turner offer are incoherent. God does not survey all possible worlds and necessarily actualize those universes in the (on balance good worlds or the worthy worlds. If God necessarily actualizes the multiverse, we have no idea which universes are parts of that multiverse. I show next that Tim O’Connor’s multiverse account of creation is also incoherent. I argue that a preferable multiverse would include a much greater variety of universes than are included in Turner, Kraay or O’Connor. In the last section I offer some concluding remarks.

  18. Network testbed creation and validation

    Energy Technology Data Exchange (ETDEWEB)

    Thai, Tan Q.; Urias, Vincent; Van Leeuwen, Brian P.; Watts, Kristopher K.; Sweeney, Andrew John

    2017-03-21

    Embodiments of network testbed creation and validation processes are described herein. A "network testbed" is a replicated environment used to validate a target network or an aspect of its design. Embodiments describe a network testbed that comprises virtual testbed nodes executed via a plurality of physical infrastructure nodes. The virtual testbed nodes utilize these hardware resources as a network "fabric," thereby enabling rapid configuration and reconfiguration of the virtual testbed nodes without requiring reconfiguration of the physical infrastructure nodes. Thus, in contrast to prior art solutions which require a tester manually build an emulated environment of physically connected network devices, embodiments receive or derive a target network description and build out a replica of this description using virtual testbed nodes executed via the physical infrastructure nodes. This process allows for the creation of very large (e.g., tens of thousands of network elements) and/or very topologically complex test networks.

  19. Creationism, Evolution, and Science Education

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Eugenie C. (National Center for Science Education)

    2005-06-22

    Many topics in the curriculum of American schools are controversial, but perhaps the one with the longest tenure is evolution. Three arguments are made against evolution: that it is allegedly weak science ('evolution is a theory in crisis'); that it is incompatible with religion; and that it is only 'fair' to 'balance' evolution with creationism. Regardless of the appropriateness of their application to science education, all three of the arguments are made to try to restrict the teaching of evolution. Variants of the fairness argument such as balancing evolution with 'scientific alternatives to evolution' or balancing evolution with 'arguments against evolution' have in fact become the current predominant antievolutionist strategy. Current events in the creationism/evolution controversy will be reviewed, and suggestions made for how to promote sound science education in the schools.

  20. Network testbed creation and validation

    Science.gov (United States)

    Thai, Tan Q.; Urias, Vincent; Van Leeuwen, Brian P.; Watts, Kristopher K.; Sweeney, Andrew John

    2017-04-18

    Embodiments of network testbed creation and validation processes are described herein. A "network testbed" is a replicated environment used to validate a target network or an aspect of its design. Embodiments describe a network testbed that comprises virtual testbed nodes executed via a plurality of physical infrastructure nodes. The virtual testbed nodes utilize these hardware resources as a network "fabric," thereby enabling rapid configuration and reconfiguration of the virtual testbed nodes without requiring reconfiguration of the physical infrastructure nodes. Thus, in contrast to prior art solutions which require a tester manually build an emulated environment of physically connected network devices, embodiments receive or derive a target network description and build out a replica of this description using virtual testbed nodes executed via the physical infrastructure nodes. This process allows for the creation of very large (e.g., tens of thousands of network elements) and/or very topologically complex test networks.

  1. Matched-pair classification

    Energy Technology Data Exchange (ETDEWEB)

    Theiler, James P [Los Alamos National Laboratory

    2009-01-01

    Following an analogous distinction in statistical hypothesis testing, we investigate variants of machine learning where the training set comes in matched pairs. We demonstrate that even conventional classifiers can exhibit improved performance when the input data has a matched-pair structure. Online algorithms, in particular, converge quicker when the data is presented in pairs. In some scenarios (such as the weak signal detection problem), matched pairs can be generated from independent samples, with the effect not only doubling the nominal size of the training set, but of providing the structure that leads to better learning. A family of 'dipole' algorithms is introduced that explicitly takes advantage of matched-pair structure in the input data and leads to further performance gains. Finally, we illustrate the application of matched-pair learning to chemical plume detection in hyperspectral imagery.

  2. Brokerage-based value creation

    DEFF Research Database (Denmark)

    Gretzinger, Susanne; Leick, Birgit

    2017-01-01

    Purpose: Resource-dependence asymmetries and risks arising from network collaboration lead to benefits and challenges. The present paper studies this trade-off, highlighting both the need and the power of moderation and brokerage as appropriate tools for network managers to handle such conflicts...... position of powerful ‘socio-centric stars’ that exercise control over the partaking members and also because there is a lack of awareness on the power base of the heterogeneous members. Value: The role of awareness for network brokers and brokerage opportunities in connection with value co-creation within...

  3. Thermodynamics of cosmological matter creation

    Science.gov (United States)

    Prigogine, I.; Geheniau, J.; Gunzig, E.; Nardone, P.

    1988-01-01

    A type of cosmological history that includes large-scale entropy production is proposed. These cosmologies are based on reinterpretation of the matter-energy stress tensor in Einstein's equations. This modifies the usual adiabatic energy conservation laws, thereby including irreversible matter creation. This creation corresponds to an irreversible energy flow from the gravitational field to the created matter constituents. This point of view results from consideration of the thermodynamics of open systems in the framework of cosmology. It is shown that the second law of thermodynamics requires that space-time transforms into matter, while the inverse transformation is forbidden. It appears that the usual initial singularity associated with the big bang is structurally unstable with respect to irreversible matter creation. The corresponding cosmological history therefore starts from an instability of the vacuum rather than from a singularity. This is exemplified in the framework of a simple phenomenological model that leads to a three-stage cosmology: the first drives the cosmological system from the initial instability to a de Sitter regime, and the last connects with the usual matter-radiation Robertson-Walker universe. Matter as well as entropy creation occurs during the first two stages, while the third involves the traditional cosmological evolution. A remarkable fact is that the de Sitter stage appears to be an attractor independent of the initial fluctuation. This is also the case for all the physical predictions involving the present Robertson-Walker universe. Most results obtained previously, in the framework of quantum field theory, can now be obtained on a macroscopic basis. It is shown that this description leads quite naturally to the introduction of primeval black holes as the intermediate stage between the Minkowski vacuum and the present matter-radiation universe. The instability at the origin of the universe is the result of fluctuations of the

  4. Dealing with Creationism in Astronomy

    Science.gov (United States)

    Bridgman, W. T.

    2005-12-01

    In recent years, the battle to force some form of pseudo-science into American science classrooms has intensified. In court cases and Boards of Education, the sides have formed between religious groups claiming to desire a `balanced' treatment and scientific groups insisting on a total ban on the topics. But there is a third option which has not been explored. Many claims of `Creation Science' and other pseudosciences can be explored and refuted at the level of introductory physics and astronomy classes. I will present a few claims of Young-Earth Creationists (YECs) pertaining to cosmology and illustrate some methods for refuting them.

  5. Thermodynamics of cosmological matter creation.

    Science.gov (United States)

    Prigogine, I; Geheniau, J; Gunzig, E; Nardone, P

    1988-10-01

    A type of cosmological history that includes large-scale entropy production is proposed. These cosmologies are based on reinterpretation of the matter-energy stress tensor in Einstein's equations. This modifies the usual adiabatic energy conservation laws, thereby including irreversible matter creation. This creation corresponds to an irreversible energy flow from the gravitational field to the created matter constituents. This point of view results from consideration of the thermodynamics of open systems in the framework of cosmology. It is shown that the second law of thermodynamics requires that space-time transforms into matter, while the inverse transformation is forbidden. It appears that the usual initial singularity associated with the big bang is structurally unstable with respect to irreversible matter creation. The corresponding cosmological history therefore starts from an instability of the vacuum rather than from a singularity. This is exemplified in the framework of a simple phenomenological model that leads to a three-stage cosmology: the first drives the cosmological system from the initial instability to a de Sitter regime, and the last connects with the usual matter-radiation Robertson-Walker universe. Matter as well as entropy creation occurs during the first two stages, while the third involves the traditional cosmological evolution. A remarkable fact is that the de Sitter stage appears to be an attractor independent of the initial fluctuation. This is also the case for all the physical predictions involving the present Robertson-Walker universe. Most results obtained previously, in the framework of quantum field theory, can now be obtained on a macroscopic basis. It is shown that this description leads quite naturally to the introduction of primeval black holes as the intermediate stage between the Minkowski vacuum and the present matter-radiation universe. The instability at the origin of the universe is the result of fluctuations of the

  6. Knowledge creation in nursing education.

    Science.gov (United States)

    Hassanian, Zahra Marzieh; Ahanchian, Mohammad Reza; Ahmadi, Suleiman; Hossein Gholizadeh, Rezvan; Karimi-Moonaghi, Hossein

    2014-09-28

    In today's society, knowledge is recognized as a valuable social asset and the educational system is in search of a new strategy that allows them to construct their knowledge and experience. The purpose of this study was to explore the process of knowledge creation in nursing education. In the present study, the grounded theory approach was used. This method provides a comprehensive approach to collecting, organizing, and analyzing data. Data were obtained through 17 semi-structured interviews with nursing faculties and nursing students. Purposeful and theoretical sampling was conducted. Based on the method of Strauss and Corbin, the data were analyzed using fragmented, deep, and constant-comparative methods. The main categories included striving for growth and reduction of ambiguity, use of knowledge resources, dynamism of mind and social factors, converting knowledge, and creating knowledge. Knowledge was converted through mind processes, individual and group reflection, praxis and research, and resulted in the creation of nursing knowledge. Discrete nursing knowledge is gained through disconformity research in order to gain more individual advantages. The consequence of this analysis was gaining new knowledge. Knowledge management must be included in the mission and strategic planning of nursing education, and it should be planned through operational planning in order to create applicable knowledge.

  7. Pairing in spherical nanograins

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmenko, N.K., E-mail: kuzmenko@NK9433.spb.ed [V.G. Khlopin Radium Institute, 2-nd Murinsky avenue 28, 194021 St.-Petersburg (Russian Federation); Mikhajlov, V.M. [Institute of Physics, St.-Petersburg State University, Ul' yanovskaya 3, 198904 Petergof (Russian Federation)

    2010-02-01

    Conditions are ascertained when the pairing and other thermodynamic properties of spherical nanograins with numbers of delocalized electrons N<10{sup 5} can be investigated by using the Single Shell Model (SSM) that gives the eigenvalues of the pairing Hamiltonian for a solitary shell. In the frame of SSM the exact canonical and grand canonical descriptions are employed first to analyze the absence of the abrupt superconducting-normal phase transition in finite systems in which an increase of the pairing and BCS critical temperature can be observed and secondly to study such new phenomena as the temperature re-entrance of the pairing in postcritical magnetic fields and also low temperature oscillations of the magnetic susceptibility and electronic heat capacity in an increasing uniform magnetic field.

  8. q¯q Pair production in non-Abelian gauge fields

    Indian Academy of Sciences (India)

    When the strength of the field is comparable to the quark masses, the corresponding pair creation probability is maximum, and for the static field w0 → 0, we recovered the well-known. Schwinger result. Keywords. Quark-gluon plasma; pair production; quarks; relative heavy-ion collisions; particles and resonance production.

  9. Lepton pairs from a forbidden M0 transition : Signaling an elusive light neutral boson?

    NARCIS (Netherlands)

    Krasznahorkay, A; De Boer, FWN; Csatlos, M; Csige, L; Gacsi, Z; Gulyas, J; Hunyadi, M; Ketel, TJ; Van Klinken, J; Krasznahorkay, A; Vitez, A

    Electron-positron pairs have been observed in the 10.95 MeV 0(-) -> 0(+) decay in O-16. This magnetic monopole (M0) transition cannot proceed by gamma-ray decay and is, to first order, forbidden for internal pair creation. However, the transition may also proceed by the emission of a light neutral

  10. Analysing performance through value creation

    Directory of Open Access Journals (Sweden)

    Adrian TRIFAN

    2015-12-01

    Full Text Available This paper draws a parallel between measuring financial performance in 2 variants: the first one using data offered by accounting, which lays emphasis on maximizing profit, and the second one which aims to create value. The traditional approach to performance is based on some indicators from accounting data: ROI, ROE, EPS. The traditional management, based on analysing the data from accounting, has shown its limits, and a new approach is needed, based on creating value. The evaluation of value based performance tries to avoid the errors due to accounting data, by using other specific indicators: EVA, MVA, TSR, CVA. The main objective is shifted from maximizing the income to maximizing the value created for shareholders. The theoretical part is accompanied by a practical analysis regarding the creation of value and an analysis of the main indicators which evaluate this concept.

  11. Value Co-creation Behaviour

    DEFF Research Database (Denmark)

    Laud, Gaurangi; Karpen, Ingo Oswald

    2017-01-01

    Purpose:The purpose of this paper is to identify antecedents and consequences ofcustomers’ value co-creation behaviour (VCB). VCB as a means to facilitatevalue realisation processes is gaining importance in service research andpractice. Encouraging such enactments can be challenging, but can also...... international weight-management firm. Findings:Results suggest that customers’ embeddedness is a key antecedent ofcustomers’ VCB in a service system. The three embeddedness dimensions –structural, relational and cultural – have a differential impact on customers’VCB. Furthermore, findings illustrate...... that customers’ VCB has a significantimpact on their object-oriented, self-oriented and brand-oriented socialvalue-in-context outcomes. Research limitations/implications:This study contributes by empirically investigating and validatingantecedents and consequences of VCB in a service system. In doing so...

  12. Skyrmion creation and annihilation by spin waves

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yizhou, E-mail: yliu062@ucr.edu; Yin, Gen; Lake, Roger K., E-mail: rlake@ece.ucr.edu [Department of Electrical and Computer Engineering, University of California, Riverside, California 92521 (United States); Zang, Jiadong [Department of Physics and Material Science Program, University of New Hampshire, Durham, New Hampshire 03824 (United States); Shi, Jing [Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States)

    2015-10-12

    Single skyrmion creation and annihilation by spin waves in a crossbar geometry are theoretically analyzed. A critical spin-wave frequency is required both for the creation and the annihilation of a skyrmion. The minimum frequencies for creation and annihilation are similar, but the optimum frequency for creation is below the critical frequency for skyrmion annihilation. If a skyrmion already exists in the cross bar region, a spin wave below the critical frequency causes the skyrmion to circulate within the central region. A heat assisted creation process reduces the spin-wave frequency and amplitude required for creating a skyrmion. The effective field resulting from the Dzyaloshinskii-Moriya interaction and the emergent field of the skyrmion acting on the spin wave drive the creation and annihilation processes.

  13. New venture creation as emerging interdependencies

    DEFF Research Database (Denmark)

    van Oorschot, Robin; Gottlieb, Frederik

    2015-01-01

    What is ‘it’ which actually takes place in the process of the creation of a new venture? Traditional research would focus on the creation of ‘the product’ or the venture. In this paper, we focus on the creation of ‘new meaning’ and emerging interdependencies between people in the process of new...... venture creation. Taking on an auto- ethnographic approach we co-construct, describe and analyse two narratives which on different levels, explore the notion of interdependency emerging in the process of creating a new venture. In our narrative approach we channel our new venture creation research...... into an evocative and analytical direction which is rarely touched upon in the dominant literature on entrepreneurship. We illustrate the value of narrative research in enabling us to investigate what new venture creation is, from an involved participant perspective. We find interdependencies as enabling...

  14. Taking Stock of Project Value Creation

    DEFF Research Database (Denmark)

    Laursen, Markus; Svejvig, Per

    2014-01-01

    This paper presents the outcome of a literature review through classifying and analyzing 59 publications in project value creation literature. The analysis led to five distinct categories: Benefit Realization Management (BRM) and techniques, broad value perspective, value time frame, engineering...... to the mid-1990s while the majority of the publications on value creation have been published since 2008. The value creation focus, or value-centric view, is thus rather recent and the research area is still developing....

  15. Designing learning for co-creation

    DEFF Research Database (Denmark)

    Larsen-Nielsen, Inger Marie; Gnaur, Dorina

    2017-01-01

    Designing learning for co-creation - conceptual and practical considerations, Dorina Gnaur and Inger Marie Larsen-Nielsen explore the practical educational point of view. The question they are posing themselves is: how can higher and further education (HE) educate for co-creation, that is, provide...... educational frameworks that respond to the societal demand for co-creation, particularly within the public welfare sector? First, they focus on which organisational and individual requirements an HE learning design should take into account in order to support the diffusion of co-creation competences...

  16. Junctionless Cooper pair transistor

    Energy Technology Data Exchange (ETDEWEB)

    Arutyunov, K. Yu., E-mail: konstantin.yu.arutyunov@jyu.fi [National Research University Higher School of Economics , Moscow Institute of Electronics and Mathematics, 101000 Moscow (Russian Federation); P.L. Kapitza Institute for Physical Problems RAS , Moscow 119334 (Russian Federation); Lehtinen, J.S. [VTT Technical Research Centre of Finland Ltd., Centre for Metrology MIKES, P.O. Box 1000, FI-02044 VTT (Finland)

    2017-02-15

    Highlights: • Junctionless Cooper pair box. • Quantum phase slips. • Coulomb blockade and gate modulation of the Coulomb gap. - Abstract: Quantum phase slip (QPS) is the topological singularity of the complex order parameter of a quasi-one-dimensional superconductor: momentary zeroing of the modulus and simultaneous 'slip' of the phase by ±2π. The QPS event(s) are the dynamic equivalent of tunneling through a conventional Josephson junction containing static in space and time weak link(s). Here we demonstrate the operation of a superconducting single electron transistor (Cooper pair transistor) without any tunnel junctions. Instead a pair of thin superconducting titanium wires in QPS regime was used. The current–voltage characteristics demonstrate the clear Coulomb blockade with magnitude of the Coulomb gap modulated by the gate potential. The Coulomb blockade disappears above the critical temperature, and at low temperatures can be suppressed by strong magnetic field.

  17. Au pair trajectories

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2015-01-01

    Since 2000, thousands of young Filipino migrants have come to Denmark as au pairs. Officially, they are there to “broaden their cultural horizons” by living temporarily with a Danish host family, but they also conduct domestic labor in exchange for food and money, which allows them to send...

  18. Paired fuzzy sets

    DEFF Research Database (Denmark)

    Rodríguez, J. Tinguaro; Franco de los Ríos, Camilo; Gómez, Daniel

    2015-01-01

    In this paper we want to stress the relevance of paired fuzzy sets, as already proposed in previous works of the authors, as a family of fuzzy sets that offers a unifying view for different models based upon the opposition of two fuzzy sets, simply allowing the existence of different types of neu...

  19. Aspectual Pairing in Polish

    NARCIS (Netherlands)

    Młynarczyk, A.K.

    2004-01-01

    The received view on Slavic aspect is that it is intrinsically complex, and that there is little hope of discerning any substantial regularity. We argue that this view is mistaken. We argue that the vast majority of Polish verbs really do come in aspectual pairs and that far from being a mysterious

  20. Excited cooper pairs

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Arrietea, M. G.; Solis, M. A.; De Llano, M. [Universidad Nacional Autonoma de Mexico, Mexico, D.F (Mexico)

    2001-02-01

    Excited cooper pairs formed in a many-fermion system are those with nonzero total center-of mass momentum (CMM). They are normally neglected in the standard Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity for being too few compared with zero CMM pairs. However, a Bose-Einstein condensation picture requires both zero and nonzero CMM pairs. Assuming a BCS model interaction between fermions we determine the populations for all CMM values of Cooper pairs by actually calculating the number of nonzero-CMM pairs relative to that of zero-CMM ones in both 2D and 3D. Although this ratio decreases rapidly with CMM, the number of Cooper pairs for any specific CMM less than the maximum (or breakup of the pair) momentum turns out to be typically larger than about 95% of those with zero-CMM at zero temperature T. Even at T {approx}100 K this fraction en 2D is still as large as about 70% for typical quasi-2D cuprate superconductor parameters. [Spanish] Los pares de cooper excitados formados en un sistema de muchos electrones, son aquellos con momentos de centro de masa (CMM) diferente de cero. Normalmente estos no son tomados en cuenta en la teoria estandar de la superconductividad de Bardeen-Cooper-Schrieffer (BCS) al suponer que su numero es muy pequeno comparados con los pares de centro de masa igual a cero. Sin embargo, un esquema de condensacion Bose-Einstein requiere de ambos pares, con CMM cero y diferente de cero. Asumiendo una interaccion modelo BCS entre los fermiones, determinamos la poblacion de pares cooper con cada uno de todos los posibles valores del CMM calculando el numero de pares con momentos de centro de masa diferente de cero relativo a los pares de CMM igual a cero, en 2D y 3D. Aunque esta razon decrece rapidamente con el CMM, el numero de pares de cooper para cualquier CMM especifico menor que el momento maximo (o rompimiento de par) es tipicamente mas grande que el 95% de aquellos con CMM cero. Aun a T {approx}100 K esta fraccion en 2D es

  1. Man creation had began since the creation of the first biological ...

    African Journals Online (AJOL)

    Among conclusions deduced from my recent deep study of holy Qur'an verses related to the topic of man creation, the man creation had begun a very long period of time before his emergence. It had begun with the creation of his earthy and clayey nature in clay. Very likely “his earthy and clayey nature” means the basic ...

  2. Community Sites of Knowledge: Knowledge Creation and ...

    African Journals Online (AJOL)

    In this article the question is asked: What is relationship between knowledge creation and sustainable peace in Africa? The specific aim of this article is to identify specific principles of knowledge creation and sustainable peace that can serve as propositions for further research. The knowledge foundation of this discussion ...

  3. Value Creation in Digital Service Platforms

    DEFF Research Database (Denmark)

    Ghazawneh, Ahmad; Mansour, Osama

    2017-01-01

    Value creation is increasingly relevant for owners of digital service platforms (DSPs). These owners have two vital goals: increase their service base and sustain their service offerers. A key element in continuously accommodating these goals is value creation. While the literature on DSPs...

  4. Neuroevolutionary Constrained Optimization for Content Creation

    DEFF Research Database (Denmark)

    Liapis, Antonios; Yannakakis, Georgios N.; Togelius, Julian

    2011-01-01

    This paper presents a constraint-based procedural content generation (PCG) framework used for the creation of novel and high-performing content. Specifically, we examine the efficiency of the framework for the creation of spaceship design (hull shape and spaceship attributes such as weapon...... and survival tasks and are also visually appealing....

  5. Crowdsourcing Content Creation in the Classroom

    Science.gov (United States)

    Hills, Thomas T.

    2015-01-01

    The recent growth in crowdsourcing technologies offers a new way of envisioning student involvement in the classroom. This article describes a participatory action research approach to combining crowdsourced content creation with the student as producer model, whereby students' interests are used to drive the identification and creation of…

  6. Evolution, Creationism, and the Courts: 20 Questions

    Science.gov (United States)

    Moore, Randy; Miksch, Karen L.

    2003-01-01

    The teaching of evolution and creationism is controversial to many people in the United States. Knowledge of the many important court-decisions about the teaching of evolution and creationism in the United States can be used not only to resist anti-evolution activities of creationists, but also to help teachers address questions about the teaching…

  7. Does Teaching Creationism Facilitate Student Autonomy?

    Science.gov (United States)

    Warnick, Bryan R.; Fooce, C. David

    2007-01-01

    The teaching of evolution in US public schools continues to generate controversy. One argument for including creationism in science classrooms is based on the goal of facilitating student autonomy. Autonomy requires that students be exposed to significant alternatives, it is argued, and religious creation stories offer a significant alternative to…

  8. Facilitating value co-creation in networks

    DEFF Research Database (Denmark)

    Rasmussen, Mette Apollo

    participants in varied ways come to grasp the meaning of networking. The dissertation draws on insights from the Service-Dominant (S-D) Logic to explain how networks can be seen as spheres for value co-creation. Co-creation as a theoretical construct has evolved from varied streams of service marketing...

  9. Designing learning for co-creation

    DEFF Research Database (Denmark)

    Larsen-Nielsen, Inger Marie; Gnaur, Dorina

    2017-01-01

    educational frameworks that respond to the societal demand for co-creation, particularly within the public welfare sector? First, they focus on which organisational and individual requirements an HE learning design should take into account in order to support the diffusion of co-creation competences...

  10. Solvothermal syntheses of Bi and Zn co-doped TiO{sub 2} with enhanced electron-hole separation and efficient photodegradation of gaseous toluene under visible-light

    Energy Technology Data Exchange (ETDEWEB)

    Li, Juan-Juan [Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Cai, Song-Cai [Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Xu, Zhen [Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Chen, Xi [Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Chen, Jin [Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Jia, Hong-Peng, E-mail: hpjia@iue.ac.cn [Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Chen, Jing, E-mail: jing.chen@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)

    2017-03-05

    Highlights: • Bi-Zn co-doped TiO{sub 2} catalysts were prepared by solvothermal route. • The incorporation of Bi doping into the TiO{sub 2} generates intermediate energy levels. • Bi and Zn doping showed the enhanced absorption in visible-light region. • Zn dopant acts as a mediator of interfacial charge transfer. • TiBi{sub 1.9%}Zn{sub 1%}O{sub 2} exhibited high photocatalytic degradation for toluene. - Abstract: This study investigated the effects of Bi doped and Bi-Zn co-doped TiO{sub 2} on photodegradation of gaseous toluene. The doped TiO{sub 2} with various concentration of metal was prepared using the solvothermal route and characterized by SEM, XRD, Raman, BET, DRS, XPS, PL and EPR. Their photocatalytic activities under visible-light irradiation were drastically influenced by the dopant content. The results showed that moderate metal doping levels were obviously beneficial for the toluene degradation, while high doping levels suppressed the photocatalytic activity. The photocatalytic degradation of toluene over TiBi{sub 1.9%}O{sub 2} and TiBi{sub 1.9%}Zn{sub 1%}O{sub 2} can reach to 51% and 93%, respectively, which are much higher than 25% of TiO{sub 2}. Bi doping into TiO{sub 2} lattice generates new intermediate energy level of Bi below the CB edge of TiO{sub 2}. The electron excitation from the VB to Bi orbitals results in the decreased band gap, extended absorption of visible-light and thus enhances its photocatalytic efficiency. Zn doping not only further enhances the absorption in this visible-light region, but also Zn dopant exists as the form of ZnO crystallites located on the interfaces of TiO{sub 2} agglomerates and acts as a mediator of interfacial charge transfer to suppress the electron-hole recombination. These synergistic effects are responsible for the enhanced photocatalytic performance.

  11. Unnatural base pair systems toward the expansion of the genetic alphabet in the central dogma

    Science.gov (United States)

    HIRAO, Ichiro; KIMOTO, Michiko

    2012-01-01

    Toward the expansion of the genetic alphabet of DNA, several artificial third base pairs (unnatural base pairs) have been created. Synthetic DNAs containing the unnatural base pairs can be amplified faithfully by PCR, along with the natural A–T and G–C pairs, and transcribed into RNA. The unnatural base pair systems now have high potential to open the door to next generation biotechnology. The creation of unnatural base pairs is a consequence of repeating “proof of concept” experiments. In the process, initially designed base pairs were modified to address their weak points. Some of them were artificially evolved to ones with higher efficiency and selectivity in polymerase reactions, while others were eliminated from the analysis. Here, we describe the process of unnatural base pair development, as well as the tests of their applications. PMID:22850726

  12. Universe creation on a computer

    Science.gov (United States)

    McCabe, Gordon

    The purpose of this paper is to provide an account of the epistemology and metaphysics of universe creation on a computer. The paper begins with F.J. Tipler's argument that our experience is indistinguishable from the experience of someone embedded in a perfect computer simulation of our own universe, hence we cannot know whether or not we are part of such a computer program ourselves. Tipler's argument is treated as a special case of epistemological scepticism, in a similar vein to 'brain-in-a-vat' arguments. It is argued that Tipler's hypothesis that our universe is a program running on a digital computer in another universe, generates empirical predictions, and is therefore a falsifiable hypothesis. The computer program hypothesis is also treated as a hypothesis about what exists beyond the physical world, and is compared with Kant's metaphysics of noumena. It is argued that if our universe is a program running on a digital computer, then our universe must have compact spatial topology, and the possibilities of observationally testing this prediction are considered. The possibility of testing the computer program hypothesis with the value of the density parameter Ω0 is also analysed. The informational requirements for a computer to represent a universe exactly and completely are considered. Consequent doubt is thrown upon Tipler's claim that if a hierarchy of computer universes exists, we would not be able to know which 'level of implementation' our universe exists at. It is then argued that a digital computer simulation of a universe, or any other physical system, does not provide a realisation of that universe or system. It is argued that a digital computer simulation of a physical system is not objectively related to that physical system, and therefore cannot exist as anything else other than a physical process occurring upon the components of the computer. It is concluded that Tipler's sceptical hypothesis, and a related hypothesis from Bostrom, cannot be

  13. First on-line positron experiments en route to pair-plasma creation

    Energy Technology Data Exchange (ETDEWEB)

    Stanja, Juliane; Hergenhahn, Uwe; Stenson, Eve V. [Max-Planck-Institut fuer Plasmaphysik (Germany); Niemann, Holger; Sunn Pedersen, Thomas [Max-Planck-Institut fuer Plasmaphysik (Germany); Ernst-Moritz-Arndt Universitaet Greifswald (Germany); Saitoh, Haruhiko [Max-Planck-Institut fuer Plasmaphysik (Germany); The University of Tokyo (Japan); Stoneking, Matthew R. [Lawrence University (United States); Hugenschmidt, Christoph; Piochacz, Christian [Technische Universitaet Muenchen (Germany); Schweikhard, Lutz [Ernst-Moritz-Arndt Universitaet Greifswald (Germany)

    2016-07-01

    Electron-positron plasmas are predicted to show a fundamentally different behavior from traditional ion-electron plasmas, because of the equal masses of the two species. Using up to 10{sup 9} positrons per second provided by the NEPOMUC (Neutron-Induced Positron Source Munich) facility, the APEX/PAX team aims to create the first such plasma confined in a toroidal magnetic trap. Positron beam parameters as well as efficient injection and confinement schemes for both species in toroidal geometries are fundamental to the project. In this contribution we present results from first on-line positron experiments. Besides characterizing the NEPOMUC beam we conducted positron injection experiments into a dipole magnetic field configuration. Using static electric fields, a 5-eV positron beam was transported across magnetic field lines into the confinement region. With this method, up to 38% of the incoming particles reach the confinement region and make at least a 180 revolution around the magnet. Under dedicated experimental conditions confinement on the order of 1 ms was realized.

  14. Reconciling the Okubo-Zweig-Iizuka rule with strong pair creation

    Energy Technology Data Exchange (ETDEWEB)

    Paul Geiger; Nathan Isgur

    1991-08-01

    One of the mysteries of the Okubo-Zweig-Iizuka (OZI) rule is that it is characterized by a scale Lambda {sub OZI} that is small compared to a typical hadronic width Gamma, whereas unitarity would lead one to expect Lambda {sub OZI} {approx} Gamma. We show that while individual virtual decay channels contribute to OZI violation with this expected strength, the coherence between all such channels can conspire to make Lambda {sub OZI} << Gamma, as observed.

  15. Millimeter-wave-induced fluxon pair creation in flux-flow Josephson oscillators

    DEFF Research Database (Denmark)

    Ustinov, A. V.; Mygind, Jesper; Pedersen, Niels Falsig

    1992-01-01

    We now observe a new type of dynamical state in long Josephson junctions. Millimeter-wave irradiation in the frequency range fext=62–77 GHz, was applied to a long junction biased in the flux-flow mode. Besides an ordinary flux-flow step satellite, flux-flow steps with voltage spacing corresponding...

  16. Designing learning for co-creation

    DEFF Research Database (Denmark)

    Larsen-Nielsen, Inger Marie; Gnaur, Dorina

    2017-01-01

    Designing learning for co-creation - conceptual and practical considerations, Dorina Gnaur and Inger Marie Larsen-Nielsen explore the practical educational point of view. The question they are posing themselves is: how can higher and further education (HE) educate for co-creation, that is, provide...... educational frameworks that respond to the societal demand for co-creation, particularly within the public welfare sector? First, they focus on which organisational and individual requirements an HE learning design should take into account in order to support the diffusion of co-creation competences....... Then they argue for the need to integrate these considerations in the learning design and demonstrate a practical application in the form of a didactical design. They call this a hybrid learning design, in that it takes advantage of technological developments to mediate co-creative learning in multiple learning...

  17. Particle Creation in Anisotropically Expanding Universe

    OpenAIRE

    Suresh, P. K.

    2003-01-01

    Using squeezed vacuum state formalism of quantum optics, an approximate solution to the semiclassical Einstein equation is obtained in Bianchi type-I universe. The phenomena of nonclassical particle creation is also examined in the anisotropic background cosmology.

  18. Evolution and Creationism: One Long Argument.

    Science.gov (United States)

    Good, Ron

    2003-01-01

    Discusses the dilemma between evolution and creationism in biology teaching. Explains the position of the Louisiana House Education Committee and presents an example from the Louisiana State University (LSU). (Author/SOE)

  19. Au pairs on Facebook

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2016-01-01

    Ethnographers are increasingly making use of Facebook to acquire access and general acquaintance with their field of study. However, little has been written on how Facebook is used methodologically in research that does not have social media sites as the main focus of interest. This article argues...... that engagement with Facebook as a methodological tool can be useful in research among migrants in highly politicised fields. Pointing to a discursive construction of Filipina au pairs as victims of labour exploitation, the article shows how fieldwork on Facebook enables the exploration of the ways in which...... and on Facebook....

  20. The potential of shared value creation: a theoretical analysis

    National Research Council Canada - National Science Library

    Victor Danciu

    2016-01-01

    .... A step forward is the concept of shared value creation. This paper aims to analyze the main features, the content of strategy of shared value creation and to propose the social innovation as main strategic way of shared value creation...

  1. Spin polarized electron-positron pair production via elliptical polarized laser fields

    CERN Document Server

    Wöllert, Anton; Keitel, Christoph H

    2015-01-01

    We study nonperturbative multiphoton electron-positron pair creation in ultra-strong electromagnetic fields formed by two counterpropagating pulses with elliptic polarization. Our numerical approach allows us to take into account the temporal as well as the spatial variation of the standing electromagnetic field. The spin and momentum resolved pair creation probabilities feature characteristic Rabi oscillations and resonance spectra. Therefore, each laser frequency features a specific momentum distribution of the created particles. We find that depending on the relative polarization of both pulses the created electrons may be spin polarized along the direction of field propagation.

  2. Pair Production Constraints on Superluminal Neutrinos Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC; Gardner, Susan; /Kentucky U.

    2012-02-16

    We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint. In summary, any model for which the CG pair production process operates is excluded because such timelike neutrinos would not be detected by OPERA or other experiments. However, a superluminal neutrino which is effectively lightlike with fixed p{sup 2} can evade the Cohen-Glashow constraint because of energy-momentum conservation. The coincidence involved in explaining the SN1987A constraint certainly makes such a picture improbable - but it is still intrinsically possible. The lightlike model is appealing in that it does not violate Lorentz symmetry in particle interactions, although one would expect Hughes-Drever tests to turn up a violation eventually. Other evasions of the CG constraints are also possible; perhaps, e.g., the neutrino takes a 'short cut' through extra dimensions or suffers anomalous acceleration in matter. Irrespective of the OPERA result, Lorentz-violating interactions remain possible, and ongoing experimental investigation of such possibilities should continue.

  3. Genetic alphabet expansion biotechnology by creating unnatural base pairs.

    Science.gov (United States)

    Lee, Kyung Hyun; Hamashima, Kiyofumi; Kimoto, Michiko; Hirao, Ichiro

    2017-10-16

    Recent studies have made it possible to expand the genetic alphabet of DNA, which is originally composed of the four-letter alphabet with A-T and G-C pairs, by introducing an unnatural base pair (UBP). Several types of UBPs function as a third base pair in replication, transcription, and/or translation. Through the UBP formation, new components with different physicochemical properties from those of the natural ones can be introduced into nucleic acids and proteins site-specifically, providing their increased functionalities. Here, we describe the genetic alphabet expansion technology by focusing on three types of UBPs, which were recently applied to the creations of DNA aptamers that bind to proteins and cells and semi-synthetic organisms containing DNAs with a six-letter alphabet. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Logistics potentials in business competitive advantage creation

    Directory of Open Access Journals (Sweden)

    Rafał Matwiejczuk

    2013-12-01

    Full Text Available Background: Companies constantly search for ways to achieve and sustain long-term competitive advantage. Among the factors influencing the competitive advantage creation there are so called logistics potentials, which constitute a component part of a business strategic potentials. Logistics resources, logistics capabilities and logistics competences are the main components of the logistics potentials structure and hierarchy. Methods: In order to recognize the logistics potentials which determine the competitive advantage creation one may use the assumptions and elements of contemporary management concepts, including strategic management. In particular the article deals with Resource-Based View (RBV, Dynamic Capabilities Concept (DCC and - first of all - Competence-Based Management (CBM. Results and conclusions: Several significant research projects have presented a wide scope and a large number of possibilities of logistics potentials (and logistics competences in particular influence on business competitive advantage creation. The article briefly presents the research results conducted by: (1 Michigan State University (USA, (2 European Logistics Association (ELA in cooperation with A.T. Kearney, (3 Computer Sciences Corporation and (4 Capgemini. The research results have pointed out to differentiated but at the same distinctive symptoms of logistics competences influence on competitive advantage creation. The article also refers to the results of the research carried out by the Chair of Logistics & Marketing at Opole University (Poland in companies operating in Poland. The research has been mainly dealing with the significance of logistics competences in competitive advantage creation.

  5. Aquinas and Contemporary Cosmology: Creation and Beginnings

    Science.gov (United States)

    Carroll, William E.

    Discussions in the Middle Ages about creation and the temporal beginning of the world involved sophisticated analyses in theology, metaphysics, and natural philosophy. Mediaeval insights on this subject, especially Thomas Aquinas' defense of the intelligibility of an eternal, created universe, can help to clarify reflections about the philosophical and theological implications of contemporary cosmological theories: from the "singularity" of the Big Bang, to "quantum tunneling from nothing," to multiverse scenarios. Thomas' insights help us to see the value of Georges Lemaître's insistence that his cosmological reflections must be kept separate from an analysis of creation. This essay will look at different senses of "beginning" and examine the claim that creation, in its fundamental meaning, tells us nothing about whether there is a temporal beginning to the universe. Multiverse models, like that recently proposed by Stephen Hawking and Leonard Mlodinow, may challenge certain views of a Grand Designer, but not of a Creator.

  6. Dynamic wormholes with particle creation mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Supriya; Chakraborty, Subenoy [Jadavpur University, Department of Mathematics, Kolkata (India)

    2015-01-01

    The present work deals with a spherically symmetric space-time which is asymptotically (at spatial infinity) FRW space-time and represents wormhole configuration: The matter component is divided into two parts - (a) dissipative but homogeneous and isotropic fluid, and (b) an inhomogeneous and anisotropic barotropic fluid. Evolving wormhole solutions are obtained when isotropic fluid is phantom in nature and there is a big rip singularity at the end. Here the dissipative phenomena is due to the particle creation mechanism in non-equilibrium thermodynamics. Using the process to be adiabatic, the dissipative pressure is expressed linearly to the particle creation rate. For two choices of the particle creation rate as a function of the Hubble parameter, the equation of state parameter of the isotropic fluid is constrained to be in the phantom domain, except in one choice, it is possible to have wormhole configuration with normal isotropic fluid. (orig.)

  7. Procedural Resource Creation in Intermediate Mechanics

    Science.gov (United States)

    Black, Katrina; Wittmann, Michael C.

    2009-11-01

    A problem in resource theory is describing the creation of new, high-level resources. We model resource creation by analyzing four student groups separating variables during a group quiz on air resistance. We assess each group's fluency and two observables: use of overt (such as divide, subtract, equals) and covert (such as moving, bringing, or pulling over) mathematical language and use of accompanying gestures (such as circling, grabbing, or sliding). For each group, the type of language and gesture used corresponds to how easily they carry out separation of variables. We create resource graphs for each group to organize our observations and use these graphs to model the creation of the procedural resource Separate Variables.

  8. Interactivity, Game Creation, Design, Learning, and Innovation

    DEFF Research Database (Denmark)

    This book constitutes the proceedings of two conferences: The 5th International Conference on ArtsIT, Interactivity and Game Creation (ArtsIT 2016) and the First International Conference on Design, Learning and Innovation (DLI 2016). ArtsIT is reflecting trends in the expanding field of digital art......, interactive art, and how game creation is considered an art form. The decision was made to augment the title of ArtsIT to be in future known as “The International Conference on Interactivity, Game Creation, Design, Learning, and Innovation”. The event was hosted in Esbjerg, Denmark in May 2016 and attracted...... 76 submissions from which 34 full papers were selected for publication in this book. The papers represent a forum for the dissemination of cutting-edge research results in the area of arts, design and technology....

  9. Creatio in musica - Creation in Music

    DEFF Research Database (Denmark)

    Schwab, Heinrich Wilhelm

    2007-01-01

    Book abstract  The meaning of the noun 'creation', and the verb 'to create', range from the traditional theological idea of God creating ex nihilo to a more recent sense of the process of artistic conception. This collection of thirteen essays, written by scholars of music, literature, the visual...... arts, and theology, explores the complicated relationship between medieval rituals and theology, and the development of an idea of human artistic creation, which came to the fore in the sixteenth century. The volume concentrates on the period from the Carolingians to the Counter-Reformation but also...... includes some twentieth-century musicians. Each essay is dedicated to a particular topic concerned with ritual or artistic beginnings, inventions, harmony and disharmony, as well as representations or celebrations of creation. Central themes include the interplay of the ideas of God as creator, of God...

  10. Distinctive Dynamic Capabilities for New Business Creation

    DEFF Research Database (Denmark)

    Rosenø, Axel; Enkel, Ellen; Mezger, Florian

    2013-01-01

    and fast-paced industries, and that similarities exist across industries. Hence, the study contributes to dynamic capabilities literature by: 1) identifying the distinctive dynamic capabilities for new business creation; 2) shifting focus away from dynamic capabilities in environments characterised by high......This study examines the distinctive dynamic capabilities for new business creation in established companies. We argue that these are very different from those for managing incremental innovation within a company's core business. We also propose that such capabilities are needed in both slow...... clock-speed and uncertainty towards considering dynamic capabilities for the purpose of developing new businesses, which also implies a high degree of uncertainty. Based on interviews with 33 companies, we identify distinctive dynamic capabilities for new business creation, find that dynamic...

  11. Organizational Values and Innovative Organizational Knowledge Creation

    Directory of Open Access Journals (Sweden)

    Lilian Aparecida Pasquini Miguel

    2009-01-01

    Full Text Available Innovation is a source of competitive advantage and is based on the continuous creation of organizational knowledge, which is supported by the individual learning. The individual learning of traditional / comportamentalist and constructivist nature can be understood, by extension, as organizational learning. The knowledge can be innovative if, along with the enabling conditions that characterize it - intention, fluctuation or chaos, autonomy, redundancy and variety of requirements – the process of learning is based on a constructivist nature, the only one capable to generate new learning solutions. The organizational values are beliefs that guide the organizations behavior and constitute motivational goals. This work had as aim to identify the relationship between organizational values and the creation of knowledge. The descriptive exploratory research used the quantitative method. The organizational values appeared in this study mainly associated to the knowledge creation aspects in the internal sphere of the organizations. The orientation towards the external environment appeared less related to the organizational values.

  12. Creationism as Science: What Every Teacher-Scientist Should Know.

    Science.gov (United States)

    Gatzke, Ken W.

    1985-01-01

    Addresses philosophical problems of the evolution/creationism debate (including underlying assumptions of creationism and nature of science), suggesting that creationism cannot be presented as science in science courses because it fails to qualify as a science. Prediction and explanation, absolute creationism, and a fundamental difficulty in…

  13. Particle creation by peak electric field

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, T.C. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Gavrilov, S.P. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Herzen State Pedagogical University of Russia, Department of General and Experimental Physics, St. Petersburg (Russian Federation); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); P. N. Lebedev Physical Institute, Moscow (Russian Federation); University of Sao Paulo, Institute of Physics, CP 66318, Sao Paulo, SP (Brazil)

    2016-08-15

    The particle creation by the so-called peak electric field is considered. The latter field is a combination of two exponential parts, one exponentially increasing and another exponentially decreasing. We find exact solutions of the Dirac equation with the field under consideration with appropriate asymptotic conditions and calculate all the characteristics of particle creation effect, in particular, differential mean numbers of created particle, total number of created particles, and the probability for a vacuum to remain a vacuum. Characteristic asymptotic regimes are discussed in detail and a comparison with the pure asymptotically decaying field is considered. (orig.)

  14. The demonism of creation in Goethe's philosophy

    Directory of Open Access Journals (Sweden)

    Nicolae Râmbu

    2012-12-01

    Full Text Available Goethe's philosophy of creativity revolves around what he called das Dämonische. This essay is not meant as a definition or an explanation of demonic creation, but instead presents a demonic work par excellence, as the term "demonic" is defined by Goethe in the Elegy from Marienbad. The process of the creation of this work, as it is described by Goethe, also represents a strange exorcism, as the entire daemonic creative force of the author is transposed in this lyrical masterpiece of German and universal literature. After writing the Elegy Goethe, it is no longer demonic.

  15. How spatial context influences entrepreneurial value creation

    DEFF Research Database (Denmark)

    Müller, Sabine

    2014-01-01

    This paper investigates how rural communities are enriched by entrepreneurial value-creating activities that go beyond job creation and growth. In addition, this study explores how spatial context influences these value-creating activities. This qualitative case-based study shows that rural......-being of the community. Thus, this study contributes to an in-depth understanding of how and why entrepreneurship can create multiple forms of value in rural areas as well as how value creation behaviours are motivated by the spatial context. In addition, it provides explanations why not all rural entrepreneurs...

  16. Networks and knowledge creation for meaning

    DEFF Research Database (Denmark)

    Brink, Tove

    2016-01-01

    . The findings show that business networks provide an important frame for organising both central- and distributed leadership to provide meaning on all levels of the network organisations. The business network consists of customers, suppliers and business partners for support of reciprocal learning for providing...... the meaning necessary for innovation. In the organising process sources of systematic storage in the enterprise, education and training and the essential knowledge creation through people need to be emphasised on the creation of meaning for innovation and reduction of LCOE. Each of these sources is important...

  17. Cooper pairs in atomic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pittel, S. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, 19716 Delaware (United States); Dussel, G. G. [Departamento de Fisica J.J. Giambiagi, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Dukelsky, J.; Sarriguren, P. [Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain)

    2008-12-15

    We describe recent efforts to study Cooper pairs in atomic nuclei. We consider a self-consistent Hartree Fock mean field for the even Sm isotopes and compare results based on three treatments of pairing correlations: a BCS treatment, a number-projected BCS treatment and an exact treatment using the Richardson Ansatz. Significant differences are seen in the pairing correlation energies. Furthermore, because it does not average over the properties of the fermion pairs, the Richardson solution permits a more meaningful definition of the Cooper wave function and of the fraction of pairs that are collective. Our results confirm that only a few pairs near the Fermi surface in realistic atomic nuclei are collective. (Author)

  18. Machine Readable Bibliographic Records: Criteria and Creation.

    Science.gov (United States)

    Bregzis, Ritvars

    The centrality of bibliographic records in library automation, objectives of the bibliographic record file and elemental factors involved in bibliographic record creation are discussed. The practical work of creating bibliographic records involves: (1) data base environment, (2) technical aspects, (3) cost and (4) operational methodology. The…

  19. Modeling value creation with enterprise architecture

    NARCIS (Netherlands)

    Singh, Prince Mayurank; Jonkers, H.; Iacob, Maria Eugenia; van Sinderen, Marten J.

    2014-01-01

    Firms may not succeed in business if strategies are not properly implemented in practice. Every firm needs to know, represent and master its value creation logic, not only to stay in business but also to keep growing. This paper is about focusing on an important topic in the field of strategic

  20. Using Informal Education through Music Video Creation

    Science.gov (United States)

    Cayari, Christopher

    2014-01-01

    Music video creation provides students a new way to express themselves and become better performers and consumers of media. This article provides a new perspective on Lucy Green's informal music pedagogy by enabling students to create music videos in music classrooms; thus, students are able to create music videos that informally develop…

  1. Entrepreneurship, job creation and wage growth

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Schjerning, Bertel; Sørensen, Anders

    2011-01-01

      This paper analyses the importance of entrepreneurs for job creation and wage growth. Relying on unique data that cover all establishments, firms and individuals in the Danish private sector, we are able to distil a number of different subsets from the total set of new establishments - subsets...

  2. Entrepreneurship, Job Creation, and Wage Growth

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Schjerning, Bertel; Sørensen, Anders

    This paper analyses the importance of entrepreneurs for job creation and wage growth. Relying on unique data that cover all establishments, firms and individuals in the Danish private sector, we are able to distil a number of different subsets from the total set of new establishments - subsets...

  3. Massive branes and creation of branes

    NARCIS (Netherlands)

    Bergshoeff, E; Dorn, H; Lust, D; Weigt, G

    1998-01-01

    We investigate the effective worldvolume theories of p-branes and D-branes in a massive background given by (the bosonic sector of) 10-dimensional massive IIA supergravity ("massive branes"). As an application we discuss the consequences of our results for the anomalous creation of branes.

  4. Haulier Value Creation in Supply Chains

    DEFF Research Database (Denmark)

    Borgström, Benedikte; Gammelgaard, Britta

    2017-01-01

    Purpose: Road transport is a dynamic sector with market changes because of liberalization and increasing demand of transport and logistics services. Shippers’ supply chain objectives of low costs and agility and a demanding operating environment due to, for example, congestion is challenging...... strategic outcomes of transport and logistics provision and supply chain value creation....

  5. On new industry creation and legitimation

    DEFF Research Database (Denmark)

    Turcan, Romeo V.; Fraser, Norman

    The purpose of this paper is to discuss the process of creation and legitimation of new industries. Specifically, the question we address is how to cross the gulf between no industry and embryonic industry in order for a new industry to emerge. In this, our focus is on the process of change from...

  6. From Creativity to New Venture Creation

    DEFF Research Database (Denmark)

    Lund, Morten; Byrge, Christian; Nielsen, Christian

    2017-01-01

    , are discussed, followed by a more in-depth discussion of the interrelationships between the creative process and the business modeling process. The implications of the paper are discussed in terms of a combined study module aimed at new venture creation students and pupils within higher education as well...

  7. Quantum creation of an inhomogeneous unflationary universe

    OpenAIRE

    Kirillov, A. A.

    1994-01-01

    The process of quantum creation of a qusihomogeneous inflationary universe near a cosmological singularity is considered. It is shown that during the evolution quantum fluctuations of spatial topologies increase and the universe acquires homogeneous and isotropic character on arbitrary large distances.

  8. Path creation in the software industry

    DEFF Research Database (Denmark)

    Leimbach, Timo

    2017-01-01

    The article analyzes the development of the German software company Software AG, which was among the few European companies that succeeded in the US market already in the 1970s. Utilizing the concept of "path creation" it examines how early success impacted the development of the company. It shows...

  9. Public Funds and Local Biotechnology Firm Creation

    NARCIS (Netherlands)

    Kolympiris, C.; Kalaitzandonakes, N.; Miller, D.

    2014-01-01

    A long stream of academic literature has established that public funding towards research and development matters for economic growth because it relates to increases in innovation, productivity and the like. The impact of public funding on the creation of new firms has received less attention in

  10. The Postmodern Sin of Intelligent Design Creationism

    Science.gov (United States)

    Pennock, Robert T.

    2010-01-01

    That Intelligent Design Creationism rejects the methodological naturalism of modern science in favor of a premodern supernaturalist worldview is well documented and by now well known. An irony that has not been sufficiently appreciated, however, is the way that ID Creationists try to advance their premodern view by adopting (if only tactically) a…

  11. Lone pairs: an electrostatic viewpoint.

    Science.gov (United States)

    Kumar, Anmol; Gadre, Shridhar R; Mohan, Neetha; Suresh, Cherumuttathu H

    2014-01-16

    A clear-cut definition of lone pairs has been offered in terms of characteristics of minima in molecular electrostatic potential (MESP). The largest eigenvalue and corresponding eigenvector of the Hessian at the minima are shown to distinguish lone pair regions from the other types of electron localization (such as π bonds). A comparative study of lone pairs as depicted by various other scalar fields such as the Laplacian of electron density and electron localization function is made. Further, an attempt has been made to generalize the definition of lone pairs to the case of cations.

  12. Stereo Pair: Patagonia, Argentina

    Science.gov (United States)

    2000-01-01

    This view of northern Patagonia, near El Cain, Argentina shows complexly eroded volcanic terrain, with basalt mesas, sinkholes, landslide debris, playas, and relatively few integrated drainage channels. Surrounding this site (but also extending far to the east) is a broad plateau capped by basalt, the Meseta de Somuncura. Here, near the western edge of the plateau, erosion has broken through the basalt cap in a variety of ways. On the mesas, water-filled sinkholes (lower left) are most likely the result of the collapse of old lava tubes. Along the edges of the mesas (several locations) the basalt seems to be sliding away from the plateau in a series of slices. Water erosion by overland flow is also evident, particularly in canyons where vegetation blankets the drainage channels (green patterns, bottom of image). However, overland water flow does not extend very far at any location. This entire site drains to local playas, some of which are seen here (blue). While the water can reach the playas and then evaporate, what becomes of the eroded rock debris? Wind might excavate some of the finer eroded debris, but the fate of much of the missing bedrock remains mysterious.This cross-eyed stereoscopic image pair was generated using topographic data from the Shuttle Radar Topography Mission, combined with an enhanced Landsat 7 satellite color image. The topography data are used to create two differing perspectives of a single image, one perspective for each eye. In doing so, each point in the image is shifted slightly, depending on its elevation. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7

  13. Instability of vortex pair leapfrogging

    DEFF Research Database (Denmark)

    Tophøj, Laust; Aref, Hassan

    2013-01-01

    Leapfrogging is a periodic solution of the four-vortex problem with two positive and two negative point vortices all of the same absolute circulation arranged as co-axial vortex pairs. The set of co-axial motions can be parameterized by the ratio 0 vortex pair sizes at the time when one...... pair passes through the other. Leapfrogging occurs for α > σ2, where is the silver ratio. The motion is known in full analytical detail since the 1877 thesis of Gröbli and a well known 1894 paper by Love. Acheson ["Instability of vortex leapfrogging," Eur. J. Phys.21, 269-273 (2000...... pairs fly off to infinity, and a "walkabout" mode, where the vortices depart from leapfrogging but still remain within a finite distance of one another. We show numerically that this transition is more gradual, a result that we relate to earlier investigations of chaotic scattering of vortex pairs [L...

  14. Potential Usefulness of Flash-Induced Superluminal Light-Echo Pairs

    Science.gov (United States)

    Nemiroff, Robert J.; Zhong, Qi

    2016-01-01

    Astronomical flashes can create transient light-echo pair phenomena that have never yet been seen but might result in useful information, if found. Toward this end, it is first proven that all light-echo spots are intrinsically superluminal. The radial component of spot speeds toward an observer, however, may be subluminal, and spot pair creation and annihilation events will be observable, in theory, when spots cross the radial superluminal speed boundary. If found, these light-echo pairs could connect angular speeds to spatial speeds, which in turn could result in the recovery of absolute sizes, three-dimensional spatial orientations, and distances to astronomical objects. A hypothetical example is given.

  15. Computational DNA hole spectroscopy: A new tool to predict mutation hotspots, critical base pairs, and disease 'driver' mutations.

    Science.gov (United States)

    Villagrán, Martha Y Suárez; Miller, John H

    2015-08-27

    We report on a new technique, computational DNA hole spectroscopy, which creates spectra of electron hole probabilities vs. nucleotide position. A hole is a site of positive charge created when an electron is removed. Peaks in the hole spectrum depict sites where holes tend to localize and potentially trigger a base pair mismatch during replication. Our studies of mitochondrial DNA reveal a correlation between L-strand hole spectrum peaks and spikes in the human mutation spectrum. Importantly, we also find that hole peak positions that do not coincide with large variant frequencies often coincide with disease-implicated mutations and/or (for coding DNA) encoded conserved amino acids. This enables combining hole spectra with variant data to identify critical base pairs and potential disease 'driver' mutations. Such integration of DNA hole and variance spectra could ultimately prove invaluable for pinpointing critical regions of the vast non-protein-coding genome. An observed asymmetry in correlations, between the spectrum of human mtDNA variations and the L- and H-strand hole spectra, is attributed to asymmetric DNA replication processes that occur for the leading and lagging strands.

  16. Computational DNA hole spectroscopy: A new tool to predict mutation hotspots, critical base pairs, and disease ‘driver’ mutations

    Science.gov (United States)

    Suárez, Martha Y.; Villagrán; Miller, John H.

    2015-01-01

    We report on a new technique, computational DNA hole spectroscopy, which creates spectra of electron hole probabilities vs. nucleotide position. A hole is a site of positive charge created when an electron is removed. Peaks in the hole spectrum depict sites where holes tend to localize and potentially trigger a base pair mismatch during replication. Our studies of mitochondrial DNA reveal a correlation between L-strand hole spectrum peaks and spikes in the human mutation spectrum. Importantly, we also find that hole peak positions that do not coincide with large variant frequencies often coincide with disease-implicated mutations and/or (for coding DNA) encoded conserved amino acids. This enables combining hole spectra with variant data to identify critical base pairs and potential disease ‘driver’ mutations. Such integration of DNA hole and variance spectra could ultimately prove invaluable for pinpointing critical regions of the vast non-protein-coding genome. An observed asymmetry in correlations, between the spectrum of human mtDNA variations and the L- and H-strand hole spectra, is attributed to asymmetric DNA replication processes that occur for the leading and lagging strands. PMID:26310834

  17. From Business Administration to Business Creation: The Case of the Kalevala Global Business Creation School

    Directory of Open Access Journals (Sweden)

    Marko Seppä

    2012-06-01

    Full Text Available Are there any businesses left to administer? The question is of course rhetorical and aimed at underscoring how several societies are more severely in need of creators of new businesses than managers of established ones. And yet, nearly all universities only produce masters of business administration, at best. Apart from theoretical research about business creation, and the education of masters of such research, universities are generally not equipped to produce knowledge for business creation or to produce masters of business creation. This conceptual article calls for a new, complementary approach to research and education, around the theme of global business creation. Due to the limitations and restrictions related to the traditions and practices of the science of business administration, where the means justify the ends, a new exploratory field coined as the “Art of Business Creation,” where the end justifies the means, is being explored for some inspiration. For a concrete solution, the concept of a globally distributed, enterprise-centric, entrepreneurial-faculty-driven, open-innovation-based, and social-media-empowered university entity is depicted in this article. It is a new-generation private-public-partnership and “Living Lab 2.0” referred to as Kalevala Global Business Creation School. The conceptualization draws from observations and action research during the Global Venture Lab Finland experiment at the University of Jyväskylä from 2007 to 2011.

  18. Making sense of Islamic creationism in Europe.

    Science.gov (United States)

    Hameed, Salman

    2015-05-01

    Islamic creationism has been noted as a serious concern in Europe. There have been reports of boycotts of university evolution lectures and, in one extreme case, even a threat of violence. While religious objections are indeed at play in some cases, our understanding of the rise of Islamic creationism should also take into account socioeconomic disparities and its impact on education for Muslim minorities in Europe. Furthermore, the broader narrative of rejection of evolution in Europe, for some Muslims, may be bound up in reactions to the secular culture and in the formation of their own minority religious identity. On the other hand, the stories of Muslim rejection of evolution in media end up reinforcing the stereotype of Muslims as "outsiders" and a threat to the European education system. A nuanced understanding of this dynamic may benefit those who support both the propagation of good science and favor cultural pluralism. © The Author(s) 2014.

  19. ICT APPROPRIATION: A KNOWLEDGE CREATION PERSPECTIVE

    DEFF Research Database (Denmark)

    Akther, Farzana

    This thesis investigates information and communication tools (ICTs) as instruments of community development processes in the context of a case study conducted in collaboration with a community empowerment program (CEP) of the non-government organization (NGO) BRAC in Bangladesh by conceptualizing...... a learning theory-based model for ICT appropriation. The aim of this research is to understand the conditions of ICT appropriation as a collective knowledge creation process within rural community development projects—and, thus, to provide tools for perceiving and constructing local ICT development...... in organizations. The study claims that ICT capacity building through a collective resource approach (participatory design) may sustain a knowledge-creation process based on hands-on participation and interaction among individuals, communities, and the sharing of artifacts and thereby offers an ICT appropriation...

  20. Shared Value Creation and Crowdfunding in Brazil

    Directory of Open Access Journals (Sweden)

    Israel José dos Santos Felipe

    2017-05-01

    Full Text Available Objective. Approaching the theory of creating shared value (Porter & Kramer, 2011 with the basic social elements of crowdfunding in Brazil. The idea was to explore the complementarity of the concepts governing the CF in line with the theory of Porter and Kramer. Through literature review and empirical discussion is intended to answer two central questions regarding the theme developed in this essay: i which elements of the theory of creating shared value are found in crowdfunding? ii how occurs the creation of shared value in business developed in crowdfunding platforms?Methodology. Theoretical Essay.Findings.  It is possible to make a theoretical approach of the themes studied in this trial, as we take the social and financial perspective of crowdfunding and their relationships with the creation of value for the company and investors.Originality. So far, was not found another study that addressed the themes of this essay in Brazil.

  1. Augmented Interactive Scores for Music Creation

    OpenAIRE

    Fober, Dominique; Orlarey, Yann; Letz, Stéphane

    2014-01-01

    International audience; This article addresses music representation issues in the context of the contemporary music creation and performance. It exposes the main challenges in terms of music notation and representation, in regard of the new forms of music and with an emphasis on interactive music issues. It presents INScore, an environment for the design of augmented, interactive music scores that has been developed in response to current artistic evolutions. It gives an overview of the syste...

  2. The creation and circulation of public geographies

    OpenAIRE

    Kitchin, Rob; Linehan, Denis; O'Callaghan, Cian; Lawton, Philip

    2013-01-01

    In response to the commentaries, we discuss further how social media disrupts and remakes the creation and circulation of geographical knowledges and potentially reconfigures the moral economy of the social sciences. In particular, we examine questions of what is meant by public geography, the publics which such geographies serve, alternative and complementary approaches to social media, the politics of authorship within collective blogs, the politics and mechanisms of knowledge c...

  3. Clinical Note Creation, Binning, and Artificial Intelligence

    OpenAIRE

    Deliberato, Rodrigo Oct?vio; Celi, Leo Anthony; Stone, David J.

    2017-01-01

    The creation of medical notes in software applications poses an intrinsic problem in workflow as the technology inherently intervenes in the processes of collecting and assembling information, as well as the production of a data-driven note that meets both individual and healthcare system requirements. In addition, the note writing applications in currently available electronic health records (EHRs) do not function to support decision making to any substantial degree. We suggest that artifici...

  4. Overcoming the Challenges of Co-creation

    Science.gov (United States)

    Pandya, R.; Udu-gama, N.; Goodwin, M.; Otellini, P.

    2016-12-01

    There is growing interest in co-creation, especially for community-related issues like climate change, resilience, pollution, and environmental justice. Nevertheless, co-creation is still not mainstream practice in either geosciences or the world of decision-makers. This presents many challenges. On the science side, challenges include a paucity of training opportunities, lack of funding for co-creation, difficulty publishing or otherwise getting credit for the effort, and a perceived lack of prestige compared to theoretical research. On the community side, parallel challenges include a lack of experience working with scientists or thinking about geoscience's relevance to community issues, tight budgets and competing priorities, the need for outputs beyond publications, and the difficulty including science among a range of factors. Additionally, scientists and community leaders often work across public and private sectors and must navigate different approaches to data, privacy, and accountability. We'll use this session to explore opportunities to overcome the challenges of co-creation. Systems thinking suggests a range of approaches: enabling individuals, reducing specific challenges, changing the relationship between the elements of the systems, and changing the goals or mindsets of the systems - each more powerful than the last. For example, mentoring and coaching enables individuals, and pro-bono work eases the challenge of getting professional credit. New modes of output, like plain language abstracts, change the relationship between publications and other outputs. We can work on changing mindsets by publicizing and celebrating individual successes. With more effort and impact, we can build collaborations in the collective impact model, where we bring scientific and community organizations together around a common agenda and shared measurement. Building on these examples, we will use this session to collect strategies and opportunities from all participants.

  5. The Read Thesaurus--creation and beyond.

    Science.gov (United States)

    Stuart-Buttle, C D; Brown, P J; Price, C; O'Neil, M; Read, J D

    1997-01-01

    The creation of the Read Thesaurus was a unique undertaking, involving over 2000 clinicians. This clinically-led, multidisciplinary enterprise posed many organisational and professional challenges. The process of term collection and integration and the problems encountered are described. A brief account is given of the large task of maintenance and refinement. This paper looks at the practical and cultural aspects and describes how problems were tackled by good organisation, clear guidelines and much goodwill.

  6. Creation of skyrmion through resonance excitation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhi-xiong; Chen, Yi-fu; Zhou, Zhen-wei; Nie, Yao-zhuang; Xia, Qing-lin; Wang, Dao-wei; Guo, Guang-hua, E-mail: guogh@mail.csu.edu.cn

    2017-07-01

    Highlights: • Intrinsic oscillation modes of skyrmion are studied by using micromagnetic simulation. • Creation of skyrmion through resonant excitation is proposed. • The number of generated skyrmions can be effectively controlled by manipulating the driving field. • Skyrmion lattice in extended film is generated via resonant excitation. - Abstract: Controllable creation of magnetic skyrmions in nanostructures is a prerequisite for the application of skyrmions in spintronics. Here, we propose a new method for the creation of skyrmions. We show by using micromagnetic simulations that the skyrmions can be nucleated by resonantly exciting one of the skyrmion intrinsic oscillation modes. We first studied the dynamics of skyrmion in a ferromagnetic nanodisk with perpendicular anisotropy. One breathing mode and two non-degenerate gyrotropic modes are identified. Then we applied a circular-polarized microwave field to excite the uniformly magnetized nanodisk. When the frequency of the driving field is equal to the eigenfrequency of the skyrmion gyrotropic mode, stable skyrmions can be created from the initial uniform state. The number of skyrmions can be effectively controlled by appropriately choosing the duration of the driving field or tuning the field amplitude.

  7. Particle creation rate for dynamical black holes

    Energy Technology Data Exchange (ETDEWEB)

    Firouzjaee, Javad T. [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), Tehran (Iran, Islamic Republic of); University of Oxford, Department of Physics (Astrophysics), Oxford (United Kingdom); Ellis, George F.R. [University of Cape Town, Mathematics and Applied Mathematics Department, Rondebosch (South Africa)

    2016-11-15

    We present the particle creation probability rate around a general black hole as an outcome of quantum fluctuations. Using the uncertainty principle for these fluctuation, we derive a new ultraviolet frequency cutoff for the radiation spectrum of a dynamical black hole. Using this frequency cutoff, we define the probability creation rate function for such black holes. We consider a dynamical Vaidya model and calculate the probability creation rate for this case when its horizon is in a slowly evolving phase. Our results show that one can expect the usual Hawking radiation emission process in the case of a dynamical black hole when it has a slowly evolving horizon. Moreover, calculating the probability rate for a dynamical black hole gives a measure of when Hawking radiation can be killed off by an incoming flux of matter or radiation. Our result strictly suggests that we have to revise the Hawking radiation expectation for primordial black holes that have grown substantially since they were created in the early universe. We also infer that this frequency cut off can be a parameter that shows the primordial black hole growth at the emission moment. (orig.)

  8. Knowledge creation and transfer among postgraduate students

    Directory of Open Access Journals (Sweden)

    Kreeson Naicker

    2014-08-01

    Objectives: This article reports on an exploratory study undertaken to ascertain how knowledge is created and transferred amongst post-graduate (PG students, using the knowledge (socialisation, externalisation, combination, internalisation [SECI] spiral model. Method: After reviewing relevant literature, a personally administered standardised questionnaire was used to collect data from a convenience sample of PG students in the School of Management, IT and Governance at the University of KwaZulu-Natal, South Africa. The data was analysed to determine if it fit the model based on the four modes of knowledge conversion. Results: Although the School of Management, IT and Governance has mechanisms in place to facilitate knowledge creation and transfer, it nevertheless tends to focus on the four modes of knowledge conversion to varying degrees. Conclusion: The study confirmed that PG students utilise the ‘socialisation’ and ‘externalisation’ modes of knowledge conversion comprehensively; ‘internalisation’ plays a significant role in their knowledge creation and transfer activities and whilst ‘combination’ is utilised to a lesser extent, it still plays a role in PG students’ knowledge creation and transfer activities. PG students also have ‘space’ that allows them to bring hunches, thoughts, notions, intuition or tacit knowledge into reality. Trust and dedication are common amongst PG students. With socialisation and externalisation so high, PG students are aware of each other’s capabilities and competencies, and trust each other enough to share knowledge.

  9. Quark pair condensation and chiral symmetry breaking in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Finger, J.R. (Massachusetts Inst. of Tech., Cambridge (USA)); Mandula, J.E. (Washington Univ., St. Louis, MO (USA))

    1982-05-17

    If the effective qanti q interaction strength due to gluon exchange becomes at least moderately strong beyond some distance g/sup 2//4..pi.. > 9/8, the perturbative vacuum becomes unstable to the creation of color singlet qanti q pairs, which indicates that the true vacuum contains a condensate of such pairs. We analyze the condensation by a coherent state variational procedure modeled after the BCS superconductor, and show that this method is equivalent to a self-consistent Hartree-Fock approximation to the Schwinger-Dyson equation for the quark propagator. The condensate leads to a spontaneous breakdown of chiral symmetry in the manner discussed by Nambu and Jona-Lasinio. The massive pseudoparticles with quark quantum numbers are identified with the 'constituent' quarks.

  10. Quark pair condensation and chiral symmetry breaking in QCD

    Science.gov (United States)

    Finger, Jonathan R.; Mandula, Jeffrey E.

    1982-05-01

    If the effective qoverlineq interaction strength due to gluon exchange becomes at least moderately strong beyond some distance g 2/4π > {9}/{8}, the perturbative vacuum becomes unstable to the creation of color singlet qoverlineq pairs, which indicates that the true vacuum contains a condensate of such pairs. We analyze the condensation by a coherent state variational procedure modeled after the BCS superconductor, and show that this method is equivalent to a self-consistent Hartree-Fock approximation to the Schwinger-Dyson equation for the quark propagator. The condensate leads to a spontaneous breakdown of chiral symmetry in the manner discussed by Nambu and Jona-Lasinio. The massive pseudoparticles with quark quantum numbers are identified with the "constituent" quarks.

  11. THE CREATION AND DEVELOPMENT OF JOB IN NIGERIA: ENTREPRENEURSHIP ENLIGHTENMENT

    OpenAIRE

    Money, Udih

    2016-01-01

    This paper is an opinion one that examined the significant role of entrepreneurship enlightenment in the creation and development of job in Nigeria. Entrepreneurship enlightenment that is continuous and reaching the citizens will help in the creation and development of job. It is viewed that entrepreneurship enlightenment is a giant stride towards creation and development of job in Nigeria. This paper also touches the challenges facing entrepreneurship development and job creation in Nigeria....

  12. Anaphoric relations in the clinical narrative: corpus creation.

    Science.gov (United States)

    Savova, Guergana K; Chapman, Wendy W; Zheng, Jiaping; Crowley, Rebecca S

    2011-01-01

    The long-term goal of this work is the automated discovery of anaphoric relations from the clinical narrative. The creation of a gold standard set from a cross-institutional corpus of clinical notes and high-level characteristics of that gold standard are described. A standard methodology for annotation guideline development, gold standard annotations, and inter-annotator agreement (IAA) was used. The gold standard annotations resulted in 7214 markables, 5992 pairs, and 1304 chains. Each report averaged 40 anaphoric markables, 33 pairs, and seven chains. The overall IAA is high on the Mayo dataset (0.6607), and moderate on the University of Pittsburgh Medical Center (UPMC) dataset (0.4072). The IAA between each annotator and the gold standard is high (Mayo: 0.7669, 0.7697, and 0.9021; UPMC: 0.6753 and 0.7138). These results imply a quality corpus feasible for system development. They also suggest the complementary nature of the annotations performed by the experts and the importance of an annotator team with diverse knowledge backgrounds. Only one of the annotators had the linguistic background necessary for annotation of the linguistic attributes. The overall generalizability of the guidelines will be further strengthened by annotations of data from additional sites. This will increase the overall corpus size and the representation of each relation type. The first step toward the development of an anaphoric relation resolver as part of a comprehensive natural language processing system geared specifically for the clinical narrative in the electronic medical record is described. The deidentified annotated corpus will be available to researchers.

  13. Photonic Counterparts of Cooper Pairs

    Science.gov (United States)

    Saraiva, André; Júnior, Filomeno S. de Aguiar; de Melo e Souza, Reinaldo; Pena, Arthur Patrocínio; Monken, Carlos H.; Santos, Marcelo F.; Koiller, Belita; Jorio, Ado

    2017-11-01

    The microscopic theory of superconductivity raised the disruptive idea that electrons couple through the elusive exchange of virtual phonons, overcoming the strong Coulomb repulsion to form Cooper pairs. Light is also known to interact with atomic vibrations, as, for example, in the Raman effect. We show that photon pairs exchange virtual vibrations in transparent media, leading to an effective photon-photon interaction identical to that for electrons in the BCS theory of superconductivity, in spite of the fact that photons are bosons. In this scenario, photons may exchange energy without matching a quantum of vibration of the medium. As a result, pair correlations for photons scattered away from the Raman resonances are expected to be enhanced. An experimental demonstration of this effect is provided here by time-correlated Raman measurements in different media. The experimental data confirm our theoretical interpretation of a photonic Cooper pairing, without the need for any fitting parameters.

  14. Exact solution for generalized pairing

    OpenAIRE

    Pan, Feng; Draayer, J. P.

    1997-01-01

    An infinite dimensional algebra, which is useful for deriving exact solutions of the generalized pairing problem, is introduced. A formalism for diagonalizing the corresponding Hamiltonian is also proposed. The theory is illustrated with some numerical examples.

  15. Contemporary African Relevance of the Genesis Creation Myth ...

    African Journals Online (AJOL)

    The book of Genesis contains two creation myths which have corollaries in the Igbo creation myth, as in other ethnic groups in Africa. This is particularly in the area of sanctity of life. The first Genesis creation mythexplicitly states that man was created in the image (Hebrew צֶלֶם ) of God, and after His likeness, (Genesis 1: ...

  16. The poetry of Sigwavhulimu: On creation and death | Mafela | South ...

    African Journals Online (AJOL)

    He does not believe in the theory of evolution, but accepts an account of the creation of the world as reflected in the book of Genesis. He also differentiates between man's creation and God's creation. Sigwavhulimu depicts death as something frightening that is dreaded by people. Two types of death are identified: the death ...

  17. Creative participation: collective sentiment in online co-creation communities

    NARCIS (Netherlands)

    Lee, H.H.M.; van Dolen, W.

    2015-01-01

    Co-creation communities allow companies to utilize consumers’ creative thinking in the innovation process. This paper seeks to understand the role of sentiment in user co-creation. The results suggest that management style can affect the success of co-creation communities. Specific employees’

  18. Deterministic creation, pinning, and manipulation of quantized vortices in a Bose-Einstein condensate

    Science.gov (United States)

    Samson, E. C.; Wilson, K. E.; Newman, Z. L.; Anderson, B. P.

    2016-02-01

    We experimentally and numerically demonstrate deterministic creation and manipulation of a pair of oppositely charged singly quantized vortices in a highly oblate Bose-Einstein condensate (BEC). Two identical blue-detuned, focused Gaussian laser beams that pierce the BEC serve as repulsive obstacles for the superfluid atomic gas; by controlling the positions of the beams within the plane of the BEC, superfluid flow is deterministically established around each beam such that two vortices of opposite circulation are generated by the motion of the beams, with each vortex pinned to the in situ position of a laser beam. We study the vortex creation process, and show that the vortices can be moved about within the BEC by translating the positions of the laser beams. This technique can serve as a building block in future experimental techniques to create, on-demand, deterministic arrangements of few or many vortices within a BEC for precise studies of vortex dynamics and vortex interactions.

  19. The European Fiscal Union creation process

    Directory of Open Access Journals (Sweden)

    Oleksandr Sharov

    2015-06-01

    Full Text Available The paper presents evolution of the European Union fiscal system creation process as well as outlines problems in functioning thereof that have arisen during recent years and the main reforming (modification trends. The analysis is primarily focused on creation of the fiscal union within the EU. In this regard, the idea of two different groups of countries moving to the common goal at different paces is becoming ever increasingly much-talked-about in the EU. The first group comprises donor countries that adhere to all treaties and fiscal discipline, while demonstrating respective positive macroeconomic indicators. The second group implies countries of Euro-periphery, where the above processes take place along with significant complications or do not occur at all. In these countries Eurosceptic positions are also quite strong, which often leads to taking measures contrary to the jointly adopted decisions. Currently, there is no clear understanding within the EU as to which way out of the crisis should be taken. However, profound understanding of the crisis causes and active work on preparation and implementation of measures to overcome the negative effects of this crisis suggest availability of sufficiently favorable prospects for further development of the EU fiscal system (including formal creation of the Fiscal Union. Based on the conducted analysis conclusions have been made as to potential vectors of action aimed at improving EU fiscal system, while specific recommendations on actions to be taken by Ukraine have been developed (particularly, as regards budget forecasting and planning with the purpose of harmonizing Ukrainian financial institutions and mechanisms with the EU fiscal system.

  20. Knowledge creation and transfer among postgraduate students

    Directory of Open Access Journals (Sweden)

    Kreeson Naicker

    2014-08-01

    Full Text Available Background: The skill shortages, hyper-competitive economic environments and untapped economies have created a great deal of focus on knowledge. Thus, continuously creating and transferring knowledge is critical for every organisation. Objectives: This article reports on an exploratory study undertaken to ascertain how knowledge is created and transferred amongst post-graduate (PG students, using the knowledge (socialisation, externalisation, combination, internalisation [SECI] spiral model. Method: After reviewing relevant literature, a personally administered standardised questionnaire was used to collect data from a convenience sample of PG students in the School of Management, IT and Governance at the University of KwaZulu-Natal, South Africa. The data was analysed to determine if it fit the model based on the four modes of knowledge conversion. Results: Although the School of Management, IT and Governance has mechanisms in place to facilitate knowledge creation and transfer, it nevertheless tends to focus on the four modes of knowledge conversion to varying degrees. Conclusion: The study confirmed that PG students utilise the ‘socialisation’ and ‘externalisation’ modes of knowledge conversion comprehensively; ‘internalisation’ plays a significant role in their knowledge creation and transfer activities and whilst ‘combination’ is utilised to a lesser extent, it still plays a role in PG students’ knowledge creation and transfer activities. PG students also have ‘space’ that allows them to bring hunches, thoughts, notions, intuition or tacit knowledge into reality. Trust and dedication are common amongst PG students. With socialisation and externalisation so high, PG students are aware of each other’s capabilities and competencies, and trust each other enough to share knowledge.

  1. The Creation Process in Digital Art

    Science.gov (United States)

    Marcos, Adérito Fernandes; Branco, Pedro Sérgio; Zagalo, Nelson Troca

    The process behind the act of the art creation or the creation process has been the subject of much debate and research during the last fifty years at least, even thinking art and beauty has been a subject of analysis already by the ancient Greeks such were Plato or Aristotle. Even though intuitively it is a simple phenomenon, creativity or the human ability to generate innovation (new ideas, concepts, etc.) is in fact quite complex. It has been studied from the perspectives of behavioral and social psychology, cognitive science, artificial intelligence, philosophy, history, design research, digital art, and computational aesthetics, among others. In spite of many years of discussion and research there is no single, authoritative perspective or definition of creativity, i.e., there is no standardized measurement technique. Regarding the development process that supports the intellectual act of creation it is usually described as a procedure where the artist experiments the medium, explores it with one or more techniques, changing shapes, forms, appearances, where beyond time and space, he/she seeks his/her way out to a clearing, i.e., envisages a path from intention to realization. Duchamp in his lecture "The Creative Act" states the artist is never alone with his/her artwork; there is always the spectator that later on will react critically to the work of art. If the artist succeeds in transmitting his/her intentions in terms of a message, emotion or feeling to the spectator then a form of aesthetic osmosis actually takes place through the inert matter (the medium) that enabled this communication or interaction phenomenon to occur. The role of the spectator may become gradually more active by interacting with the artwork itself possibly changing or becoming a part of it [2][4].

  2. Knowledge creation and transfer among postgraduate students

    Directory of Open Access Journals (Sweden)

    Kreeson Naicker

    2014-03-01

    Full Text Available Background: The skill shortages, hyper-competitive economic environments and untapped economies have created a great deal of focus on knowledge. Thus, continuously creating and transferring knowledge is critical for every organisation.Objectives: This article reports on an exploratory study undertaken to ascertain how knowledge is created and transferred amongst post-graduate (PG students, using the knowledge (socialisation, externalisation, combination, internalisation [SECI] spiral model.Method: After reviewing relevant literature, a personally administered standardised questionnaire was used to collect data from a convenience sample of PG students in the School of Management, IT and Governance at the University of KwaZulu-Natal, South Africa. The data was analysed to determine if it fit the model based on the four modes of knowledge conversion.Results: Although the School of Management, IT and Governance has mechanisms in place to facilitate knowledge creation and transfer, it nevertheless tends to focus on the four modes of knowledge conversion to varying degrees.Conclusion: The study confirmed that PG students utilise the ‘socialisation’ and ‘externalisation’ modes of knowledge conversion comprehensively; ‘internalisation’ plays a significant role in their knowledge creation and transfer activities and whilst ‘combination’ is utilised to a lesser extent, it still plays a role in PG students’ knowledge creation and transfer activities. PG students also have ‘space’ that allows them to bring hunches, thoughts, notions, intuition or tacit knowledge into reality. Trust and dedication are common amongst PG students. With socialisation and externalisation so high, PG students are aware of each other’s capabilities and competencies, and trust each other enough to share knowledge.

  3. Value co-creation in healthcare through positive deviance.

    Science.gov (United States)

    Zanetti, Cole Anthony; Taylor, Natalie

    2016-12-01

    To explore how converging fields of co-creation and positive deviance may increase value in healthcare. Informed by research in positive deviance, patient engagement, value co-creation, and quality improvement, we propose a positive deviance approach to co-creation of health. Co-creation has shown to improve health outcomes with regard to multiple health conditions. Positive deviance has also shown to improve outcomes in multiple healthcare and patient community environments. A positive deviance co-creation framework may aid in achieving improved outcomes for patients, care teams and their respective healthcare organizations. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Enacting entrepreneurship as social value creation

    DEFF Research Database (Denmark)

    Korsgaard, Steffen T.; Anderson, Alistair

    2011-01-01

    situated. Accordingly, this article examines the enactment of a socialized opportunity to explore the process of entrepreneurial growth. We find that a conceptualization of social value creation usefully develops our understanding and challenges the view that economic growth is the only relevant outcome...... of entrepreneurship. Our case study shows how social value is created in multiple forms at different centres and on different levels: from individual self-realization over community development to broad societal impact. We also find complex interrelations between the different levels and centres, thus, we argue...... that entrepreneurship is as much a social as an economic phenomenon...

  5. From creation and annihilation operators to statistics

    Science.gov (United States)

    Hoyuelos, M.

    2018-01-01

    A procedure to derive the partition function of non-interacting particles with exotic or intermediate statistics is presented. The partition function is directly related to the associated creation and annihilation operators that obey some specific commutation or anti-commutation relations. The cases of Gentile statistics, quons, Polychronakos statistics, and ewkons are considered. Ewkons statistics was recently derived from the assumption of free diffusion in energy space (Hoyuelos and Sisterna, 2016); an ideal gas of ewkons has negative pressure, a feature that makes them suitable for the description of dark energy.

  6. Entrepreneurship, job creation and wage growth

    OpenAIRE

    Malchow-Møller, Nikolaj; Schjerning, Bertel; Sørensen, Anders

    2011-01-01

    This paper analyses the importance of entrepreneurs in terms of job creation and wage growth. Relying on unique data that cover all establishments, firms and individuals in the Danish private sector, we are able to distil a number of different subsets from the total set of new establishments—subsets which allow us to more precisely capture the “truly new” or “entrepreneurial” establishments than has been possible in previous studies. Using these data, we find that while new establishments in ...

  7. ZBrush Character Creation Advanced Digital Sculpting

    CERN Document Server

    Spencer, Scott

    2011-01-01

    A stunning, content-rich update to this top-selling ZBrush guide! This second edition of ZBrush Character Creation has been fully updated for ZBrush 4, the newest version of this fascinating and popular 3D sculpting software. ZBrush enables users to create detailed organic models using a brush-based toolset and tablet. The startling results look as though they've been painted with real brushes and oils, and ZBrush is increasingly popular for use in film, game, and broadcast pipelines. Author Scott Spencer is embedded in the ZBrush community and his movie credits include Harry Potter and The Or

  8. Service Creation and Deployment in Converged Networks

    DEFF Research Database (Denmark)

    Soler, José

    This monograph (Early Experiences related to Service Creation & Deployment in Converged Networks) presents different experiences related to architectures and mechanisms for deployment of telephony services, understood as especial features complementing the basic voice service. The context...... and Future Converged Networks”, carried out at the Technical University of Denmark in the period [April 2002-April 2005]. Even though the technologies presented in the text have evolved from that period until now, the presented scenarios and setups are still valid as interesting initial steps in the realm....

  9. Called home: The creation of family life.

    Science.gov (United States)

    Hutch, R A

    1992-09-01

    Engendering family life is a spiritual process (theosis) based on human ethological constants of gender difference and generational turnover. Recent studies on ethnicity suggest that such a process retrieves a primordial sense of the human species as a whole, "humankind." Families, especially in this broad sense, link together the living and the dead and, at their best, morally empower individuals who link their destinies to such a vision of creation and human health. Reference is made to work on human strengths and speciation by Erik Erikson and to that on maternal thinking by Sara Ruddick. A political program by which an ideology of "familism" can be made is offered.

  10. Cooper pairing of two-dimensional electrons in a quantizing magnetic field and the fractional quantum Hall effect

    Science.gov (United States)

    Pashitskiĭ , E. A.

    1999-08-01

    A brief review of the current state of the theory of fractional quantum Hall effect (FQHE) is given along with the assumption of possible connection between the experimentally observed features of the Hall resistance RH of a two-dimensional (2D) electron system in a strong quantizing magnetic field for a fractional filling factor of the lowest Landau level ν=q/(2n+1) with q⩾2, which cannot be described by the Laughlin wave function antisymmetric relative to pair transpositions, and the Cooper pairing of 2D electrons. It is assumed that the electron-electron attraction essential for Cooper pairing can be due to the interaction of 2D electrons with the surface acoustic waves (2D phonons) and the surface 2D plasmons localized near the crystal interfaces (heterojunctions) in the vicinity of inversion layers in the metal-insulator-semiconductor (MIS) structures and heterostructures. The coexistence of coupled electron pairs and unpaired electrons under the FQHE conditions must lead to peculiarities of RH for values of ν described by the Halperin relation following from the symmetry properties of the "mixed" wave function of pairs (bosons) and electrons (fermions). This relation makes it possible in principle to describe all experimental data on FQHE. The summation of "ladder" diagrams diverging according to a power law for T→0 leads to a Bethe-Salpeter-type equation for the vertex part of the electron-electron interaction for a 2D system in a quantizing magnetic field taking into account electron-electron and electron-hole pairing in the Cooper and zero-sound channels. This equation is used to calculate the critical temperature Tc of the phase transition to the state with coupled Cooper pairs and to prove that the value of Tc in the ultra-quantum limit is independent of the effective mass of electrons, i.e., on the 2D density of states. The phase diagram of the 2D system is constructed for the variable electron concentration and magnetic field. It is shown that

  11. Creation of targeted inversion mutations in plants using an RNA-guided endonuclease

    Directory of Open Access Journals (Sweden)

    Congsheng Zhang

    2017-02-01

    Full Text Available Inversions are DNA rearrangements that are essential for plant gene evolution and adaptation to environmental changes. We demonstrate the creation of targeted inversions and previously reported targeted deletion mutations via delivery of a pair of RNA-guided endonucleases (RGENs of CRISPR/Cas9. The efficiencies of the targeted inversions were 2.6% and 2.2% in the Arabidopsis FLOWERING TIME (AtFT and TERMINAL FLOWER 1 (AtTFL1 loci, respectively. Thus, we successfully established an approach that can potentially be used to introduce targeted DNA inversions of interest for functional studies and crop improvement.

  12. Rents in property rights creation and implementation

    Directory of Open Access Journals (Sweden)

    Žarković Jelena

    2006-01-01

    Full Text Available The institution of property rights is increasingly being recognized as an essential building block of an economically prosperous society. The question that remains unanswered however, is how do we develop effective property rights institutions? The literature dealing with the development of property rights tends to be, in general, overly optimistic since there is a tendency to view the design of property rights institutions as optimizing decisions to economize on transaction costs and to facilitate new economic activities. On the other hand, since property rights define the distribution of wealth and political power in a society changes in property rights structures are likely to be influenced by more than pure efficiency considerations. Therefore, in order to achieve a balanced analysis of the evolution of property rights institutions our article introduces the state in the whole process. Following the propositions of the interest group theory of government we show an important relationship between rent seeking and state involvement in property rights creation. The state with a coercive power to establish and enforce property rights can also use that power, through the process of economic regulation, to redistribute property rights to politically influential interest groups. Herein lies the state failure in property rights creation.

  13. ARTISTIC AND SCIENTIFIC CREATION PROCESS MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Ioan Tudor

    2013-12-01

    Full Text Available Cultural creation is not ex nihilo, but a conversion of old “material” into a new form or a re-signifying, or a new combination of preexisting elements. Art, as well as science, has been characterized as acts of dominating and transforming nature. In art, the process is real and in science it is virtual. This process is characterized by an efficient management of the means of expression which must be subordinated to the message that the piece of art wants to transmit and the scientist exploits facts in order to make them significant as support, expression and exemplification of the laws of nature. There is also an ontogenesis of management: individual evolution which takes place by virtue of a program, thanks to devices with self-regulating capabilities. This aspect may be particularly interesting for cyberneticists. In contemporary civilization the transfer of certain aspects of the creation process to automated machines implies programming, algorithms. Man is an algorithmic being.

  14. [Creation of artificial urinary bladder in children].

    Science.gov (United States)

    Nikolaev, V V; Braev, A T; Shamatrin, S V

    2001-01-01

    In children creation of artificial urinary bladder using intestinal segments was made in the absent or reduced reservoir function of the bladder. From 1990 to 1998 enterocystoplasty was performed in 30 boys and 6 girls. 15 of them have undergone colocystoplasty, 21--ileocystoplasty with detubulized segment. Holding conduits were made of the appendix or intestinal segment in 31 patients. On postoperative day 1-16 six patients developed complications demanding emergency operation--3 cases of comissural ileus and 3 of urinary peritonitis. 33 patients were followed up for 1 to 9 years. 29 patients urinated only through catheter 3 to 6 times a day. 4 patients urinated without a catheter but they had imperative enuresis. Concrements in the artificial bladder were detected in 8 postcolocystoplasty patients and 1 postileocystoplasty patient. The preference was given to ileocystoplasty with detubulized segment with creation of the holding conduit and occlusion of the bladder neck. The ileal artificial bladder is characterized by less probable long-term complications, greater volume, low pressure at filling, less intensive mucus production.

  15. All new custom path photo book creation

    Science.gov (United States)

    Wang, Wiley; Muzzolini, Russ

    2012-03-01

    In this paper, we present an all new custom path to allow consumers to have full control to their photos and the format of their books, while providing them with guidance to make their creation fast and easy. The users can choose to fully automate the initial creation, and then customize every page. The system manage many design themes along with numerous design elements, such as layouts, backgrounds, embellishments and pattern bands. The users can also utilize photos from multiple sources including their computers, Shutterfly accounts, Shutterfly Share sites and Facebook. The users can also use a photo as background, add, move and resize photos and text - putting what they want where they want instead of being confined to templates. The new path allows users to add embellishments anywhere in the book, and the high-performance platform can support up to 1,000 photos per book and up to 25 pictures per page. The path offers either Smart Autofill or Storyboard features allowing customers to populate their books with photos so they can add captions and customize the pages.

  16. Organometallic frustrated Lewis pair chemistry.

    Science.gov (United States)

    Erker, Gerhard

    2011-08-07

    Frustrated Lewis pairs are playing an increasingly important role in organometallic chemistry. Examples are presented and discussed where organometallic systems themselves serve as the Lewis base or Lewis acid components in frustrated Lewis pair chemistry, mostly through their attached functional groups. Activation of dihydrogen takes place easily in many of these systems. This may lead to the generation of novel catalyst systems but also in many cases to the occurrence of specific reactions at the periphery of the organometallic frameworks. Increasingly, FLP reactions are used to carry out functional group conversions in organometallic systems under mild reaction conditions. The limits of typical FLP reactivity are explored with selected organometallic examples, a discussion that points toward new developments, such as the discovery of facile new 1,1-carboboration reactions. Learning more and more about the broad spectrum of frustrated Lewis pair chemistry helps us to find novel reactions and applications.

  17. Atomic pair-state interferometer

    DEFF Research Database (Denmark)

    Nipper, J.; Balewski, Jonathan B.; Krupp, Alexander T.

    2012-01-01

    We present experiments measuring an interaction-induced phase shift of Rydberg atoms at Stark-tuned Förster resonances. The phase shift features a dispersive shape around the resonance, showing that the interaction strength and sign can be tuned coherently. We use a pair-state interferometer...

  18. Pairs of dual periodic frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Goh, Say Song

    2012-01-01

    is needed. The purpose of the present paper is to provide constructions of dual pairs of frames in the setting of the Hilbert space of periodic functions L2(0,2π). The frames constructed are given explicitly as trigonometric polynomials, which allows for an efficient calculation of the coefficients...

  19. Instantons in lepton pair production

    NARCIS (Netherlands)

    Brandenburg, A.; Ringwald, A.; Utermann, A.

    2006-01-01

    We consider QCD instanton-induced contributions to lepton pair production in hadron-hadron collisions. We relate these contributions to those known from deep inelastic scattering and demonstrate that they can be calculated reliably for sufficiently large momentum transfer. We observe that the

  20. Conjugal Pairing in Escherichia Coli

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 8. Conjugal Pairing in Escherichia Coli. Joshua Lederberg. Classics Volume 13 Issue 8 August 2008 pp 793-794. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/013/08/0793-0794 ...

  1. Pairing Linguistic and Music Intelligences

    Science.gov (United States)

    DiEdwardo, MaryAnn Pasda

    2005-01-01

    This article describes how music in the language classroom setting can be a catalyst for developing reading, writing, and understanding skills. Studies suggest that pairing music and linguistic intelligences in the college classroom improves students' grades and abilities to compose theses statements for research papers in courses that emphasize…

  2. Autonomous Rule Creation for Intrusion Detection

    Energy Technology Data Exchange (ETDEWEB)

    Todd Vollmer; Jim Alves-Foss; Milos Manic

    2011-04-01

    Many computational intelligence techniques for anomaly based network intrusion detection can be found in literature. Translating a newly discovered intrusion recognition criteria into a distributable rule can be a human intensive effort. This paper explores a multi-modal genetic algorithm solution for autonomous rule creation. This algorithm focuses on the process of creating rules once an intrusion has been identified, rather than the evolution of rules to provide a solution for intrusion detection. The algorithm was demonstrated on anomalous ICMP network packets (input) and Snort rules (output of the algorithm). Output rules were sorted according to a fitness value and any duplicates were removed. The experimental results on ten test cases demonstrated a 100 percent rule alert rate. Out of 33,804 test packets 3 produced false positives. Each test case produced a minimum of three rule variations that could be used as candidates for a production system.

  3. Entanglement creation in low-energy scattering

    Energy Technology Data Exchange (ETDEWEB)

    Weder, Ricardo [Institut National de Recherche en Informatique et en Automatique Paris-Rocquencourt, Projet POEMS, Domaine de Voluceau-Rocquencourt, BP 105, F-78153, Le Chesnay Cedex (France)

    2011-12-15

    We study the entanglement creation in the low-energy scattering of two particles in three dimensions, for a general class of interaction potentials that are not required to be spherically symmetric. The incoming asymptotic state, before the collision, is a product of two normalized Gaussian states. After the scattering, the particles are entangled. We take as a measure of the entanglement the purity of one of them. We provide a rigorous explicit computation, with error bound, of the leading order of the purity at low energy. The entanglement depends strongly on the difference of the masses. It takes its minimum when the masses are equal, and it increases rapidly with the difference of the masses. It is quite remarkable that the anisotropy of the potential gives no contribution to the leading order of the purity, in spite of the fact that entanglement is a second-order effect.

  4. The Creation and Destruction of Social Capital

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Svendsen, Gert Tinggaard

    are urging all social scientists to think more as social scientists rather than just as anthropologists, economists, historians, political scientists, or sociologists. Their effort to broaden the way social scientists think about social organization is an important step, especially for those of us interested...... in public policies. . . This is the type of book that should be assigned to graduate students across the social sciences as an illustration of the kind of work that they should aspire to do. I know I have learned a great deal from reading this book and appreciate the effort that the Svendsens have put......‘A welcome contribution to scholarly economic and public policy debates, The Creation and Destruction of Social Capital is written for advanced students yet offers insights critical to better understanding micro and macro economics alike.' - Willis M. Buhle, The Midwest Book Review ‘The Svendsens...

  5. Explaining money creation by commercial banks

    DEFF Research Database (Denmark)

    Ravn, Ib

    2015-01-01

    Educators and economists concerned with monetary reform face the extraordinary challenge of explaining to the public and its elected representatives not only what a reformed system would look like, but also how the current system works. Centrally, the point that in a modern economy money is largely...... created by commercial banks, as explained by the Bank of England recently (McLeay, Radia & Thomas, 2014b), is often met with incredulity: “What do you mean, created?” This paper introduces five easy-to-grasp analogies that educators and reformers may use to convey key money-creation concepts to a lay...... audience. The analogies offered include (1) money as patches in an expandable patchwork quilt that covers a nation’s real assets, (2) the money supply as water in a bathtub with a faucet and a drain, (3) money understood as debt in a model economy run by schoolchildren, (4) the misleading concept of a bank...

  6. Co-Creation in Higher Education

    DEFF Research Database (Denmark)

    The main purpose of this book is to disseminate new research on co-creative approaches to teaching and learning in Higher Education (HE). The cases presented draw from a Danish cultural and educational context and have a special focus on collaborative, co-creative and distributed perspectives......-led learning, arts-based approaches to higher educational research and teaching, collaborative practices. We believe that these perspectives are still in need of further investigation through theories and practices. We understand co-creation as the process of creative, original and valuable generation...... of shared meaning and development. This collected volume offers novel empirical documentation and original theoretical reflections on the application of co-creative processes in higher education. This can be directly relevant for educators and the ways in which they design education, but also for students...

  7. Creative Re-creation in Cultural Migration

    Directory of Open Access Journals (Sweden)

    Da Zheng

    2017-07-01

    Full Text Available Lady Precious Stream by Shih-I Hsiung was the first successful West End play by a Chinese playwright. Based on a traditional Chinese opera but with many changes, the play had an enormous appeal to the modern audience in the West. This paper argues that the play is essentially an ingenious re-creation in which Hsiung has undertaken a combination of three roles: translating the original into English; adapting it to the English theatrical practice while maintaining the Chinese convention; and re-writing some of the details. Hsiung is thus able to keep the original cultural elements with sensitivity to the taste, convention, and ethical values of the targeted audience, transforming the ancient Chinese opera into a modern English-language play. Lady Precious Stream reveals the evolution and mutation of literary products that cross cultural and geographical boundaries as well as the significant role a writer may play in transcultural exchanges.

  8. From Creativity to New Venture Creation

    DEFF Research Database (Denmark)

    Lund, Morten; Byrge, Christian; Nielsen, Christian

    2017-01-01

    , are discussed, followed by a more in-depth discussion of the interrelationships between the creative process and the business modeling process. The implications of the paper are discussed in terms of a combined study module aimed at new venture creation students and pupils within higher education as well......This paper explores the processes of creating new companies with original and useful business models from a conceptual perspective. Based on data from large-scale creativity training programs and business model development studies in Denmark encompassing over 100 companies and 200 entrepreneurs......, the key proposition of the paper is that entrepreneurs can enhance their development processes through training of their competences in creativity and in business modeling. The paper presents a set of key skill variables of creativity and of business modeling that need to be trained in order to enhance...

  9. Collaborative Creation of a Lab Rubric

    Directory of Open Access Journals (Sweden)

    Carrie Miller-DeBoer

    2011-03-01

    Full Text Available While there are a number of tested rubrics in circulation, our task was to intervene in a particular situation: the lead professor was concerned because her graduate teaching assistants held negative views about student performance on the lab reports. GTAs found poor products frustrating, and admitted that their grading was thus superficial and provided no feedback to students. Specifically, GTAs did not feel equipped to evaluate writing and, as a result, simply graded on steps completed in the lab process.We have a rubric now for an Introduction to Zoology lab that could be submitted here as a pretty darn good rubric for other instructors to use. But the intent of our “Tips and Tools” is to describe the actual creation of the rubric. We believe the active “real time” development of the rubric carried as much or more value than the finished product.

  10. Urban Social initiatives and Co-creation

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte; Rasmussen, Jørgen

    2016-01-01

    As part of the 2014 fall semester study programme, Studio Design and Social Innovation, from Aarhus School of Architecture, collaborated with DemokraCity on a community initiative project to revitalize TILST, a town located on the outskirts of Aarhus, Denmark. Demokracity focuses on urban social...... to social class segregation. This paper will describe how interventions in Tilst, in collaboration with local residents, help devise social initiatives that aim at improving the local community identity. The project is concerned with examining the potentials of a place, and with initiating a new use...... initiatives and co-creation design projects that encourage citizens’ community involvement, commitment, and collaboration. Initiated by the Aarhus City Council, “NEW ANGLES ON TILST” aims at involving residents and local stakeholders directly in the development and planning of the neighbourhoods in close...

  11. From Creativity to New Venture Creation

    DEFF Research Database (Denmark)

    Nielsen, Christian; Byrge, Christian; Lund, Morten

    2016-01-01

    creativity training, as well as a software-based framework for identifying useful business model configurations. The notion and potential effect of each program as separate tools is discussed, followed by a more in-depth discussion of the interrelationships between creative processes, opportunity spotting...... and the choice of business model configurations. The implications of the paper are discussed in terms of a research program under establishment as well as a combined teaching module aimed at new venture creation students within higher-education, high schools and primary school levels.......This paper explores the processes of creating new companies with original and useful business models from a conceptual perspective. Based on data from large-scale creativity training programs and business model development studies in Denmark encompassing over 100 companies and 200 entrepreneurs...

  12. Origins the scientific story of creation

    CERN Document Server

    Baggott, Jim

    2015-01-01

    What is the nature of the material world? How does it work? What is the universe and how was it formed? What is life? Where do we come from and how did we evolve? How and why do we think? What does it mean to be human? How do we know? There are many different versions of our creation story. This book tells the version according to modern science. It is a unique account, starting at the Big Bang and travelling right up to the emergence of humans as conscious intelligent beings, 13.8 billion years later. Chapter by chapter, it sets out the current state of scientific knowledge: the origins of space and time; energy, mass, and light; galaxies, stars, and our sun; the habitable earth, and complex life itself. Drawing together the physical and biological sciences, Baggott recounts what we currently know of our history, highlighting the questions science has yet to answer.

  13. Clinical Note Creation, Binning, and Artificial Intelligence.

    Science.gov (United States)

    Deliberato, Rodrigo Octávio; Celi, Leo Anthony; Stone, David J

    2017-08-03

    The creation of medical notes in software applications poses an intrinsic problem in workflow as the technology inherently intervenes in the processes of collecting and assembling information, as well as the production of a data-driven note that meets both individual and healthcare system requirements. In addition, the note writing applications in currently available electronic health records (EHRs) do not function to support decision making to any substantial degree. We suggest that artificial intelligence (AI) could be utilized to facilitate the workflows of the data collection and assembly processes, as well as to support the development of personalized, yet data-driven assessments and plans. ©Rodrigo Octávio Deliberato, Leo Anthony Celi, David J Stone. Originally published in JMIR Medical Informatics (http://medinform.jmir.org), 03.08.2017.

  14. Tending the tensions in co-creation

    DEFF Research Database (Denmark)

    Phillips, Louise Jane

    -creation as a process of mutual learning to be valued at least as much as the outcome AND the neoliberal instrumentalisation of creativity in the service of social innovation and economic growth. The papers build on the themes of Knowledge and Power in Collaborative Research: A Reflexive Approach (Phillips, Kristiansen......Across fields of social practice, the harnessing of creativity in collaborative, dialogic processes of knowledge production is championed as a means to empower participants as agents and generate practice change. ‘Collaboration’, ‘dialogue’ and ‘participation’ have become buzzwords with a taken...... et al, Routledge, 2012), adopting a critical, reflexive approach that interrogates the tensions AND is committed to developing co-creative methods....

  15. Tending the tensions in co-creation

    DEFF Research Database (Denmark)

    Phillips, Professor MSO Louise; Nordentoft, Helle Merete; Pedersen, Lektor Christina Hee

    2013-01-01

    -creation as a process of mutual learning to be valued at least as much as the outcome AND the neoliberal instrumentalisation of creativity in the service of social innovation and economic growth. The papers build on the themes of Knowledge and Power in Collaborative Research: A Reflexive Approach (Phillips, Kristiansen......Across fields of social practice, the harnessing of creativity in collaborative, dialogic processes of knowledge production is championed as a means to empower participants as agents and generate practice change. ‘Collaboration’, ‘dialogue’ and ‘participation’ have become buzzwords with a taken...... et al, Routledge, 2012), adopting a critical, reflexive approach that interrogates the tensions AND is committed to developing co-creative methods....

  16. Pairing gaps in nucleonic superfluids

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.M.C. (McDonnell Center for the Space Sciences and Dept. of Physics, Washington Univ., St. Louis, MO (United States)); Clark, J.W. (McDonnell Center for the Space Sciences and Dept. of Physics, Washington Univ., St. Louis, MO (United States)); Dave, R.D. (McDonnell Center for the Space Sciences and Dept. of Physics, Washington Univ., St. Louis, MO (United States)); Khodel, V.V. (McDonnell Center for the Space Sciences and Dept. of Physics, Washington Univ., St. Louis, MO (United States))

    1993-04-05

    Singlet S-wave nucleonic superfluids are studied within a microscopic many-body theory that incorporates explicit spatial correlations due to strong short-range repulsive forces as well as the momentum-space pairing correlations of BCS theory. The theory is formulated within the method of correlated basis functions (CBF). Within this scheme, there results a nonlinear problem for the superfluid energy gap that is identical in form to the gap problem of conventional BCS theory. However, the input single-particle energies and pairing matrix elements are dressed by the short-range spatial correlations and accordingly incorporate an important class of medium corrections. The effective pairing force of the theory is finite even if the bare two-nucleon potential contains an infinitely hard core; both the pairing matrix elements and single-particle energies are to be constructed from normal-state CBF matrix elements and may be evaluated by cluster-expansion techniques. The theory is explicated and applied at a variational level that is equivalent to the leading order of a CBF superstate perturbation theory. New results are presented for the [sup 1]S[sub 0] pairing gap [Delta][sub kF] in pure neutron matter at densities relevant to the inner crust of a neutron star, based on a simplified version of the Reid soft-core interaction and spin-dependent spatial correlations optimized in the correlated normal state. Careful considering is given to the treatment of the gap equation at large intermediate-state momenta. The variational gap function evaluated at the Fermi surface, [Delta][sub F], is found to be larger than predicted in earlier work. Estimates of the suppression of the gap due to polarization processes (and other particle-particle and hole-irreducible medium effects of higher order within CBF superstate perturbation theory) yield values of [Delta][sub kF].

  17. OPTICAL DEFLECTOR CREATION FOR LASER THERAPEUTIC DEVICES

    Directory of Open Access Journals (Sweden)

    V. N. Baranov

    2014-03-01

    Full Text Available The paper deals with creation of optical deflector for management of laser radiation in physiotherapeutic devices. Design features and operation principles of electro-optical, optical-acoustic and mechanical deflectors, giving the possibility to carry out continuous or discrete scanning of a laser beam are shown. Operation mechanism of the mechanical type deflector on the example of domestic laser therapeutic scanners is described in detail. Application possibility in clinical practice for heating technique of the acupuncture points by volumetric scanning of tissues by the radiation of semiconductor lasers on wave lengths equal to 0,67 and 0,85 μm is investigated. Creation justification of the new type deflector is given. Comparison between stable and labile techniques of radiation is carried out. It is shown that more intensive warming up of a skin surface in acupuncture point projection is observed at volumetric scanning, rather than at planar scanning by laser beams. Temperature increase on a skin surface in projection of acupuncture points is detected at radiation in both the visible spectrum range (0,67 μm and the infrared range (0,85 μm. It gives the possibility to apply this scanning method to thermal photo-activation of the point and to extend an existing arsenal of laser reflexology methods. The optical deflector is offered for medical industry, making it possible to carry out volumetric scanning of a laser beam and to facilitate the medical personnel’s work in laser therapy and reflexology consulting rooms.

  18. Perspectives on the Logos’ immanence in Creation

    Directory of Open Access Journals (Sweden)

    Nicolae Moșoiu

    2016-03-01

    Full Text Available „The reasons of things that God prepared in advance for ages, as He Himself knew, can be seen through understanding from the creatures. For every creature of God, contemplated by us through nature, using science and knowledge, proclaim in a hidden manner the reasons after which they were made and they reveal the purpose placed by God in every creature. From the wise contemplation of creation we can perceive the Reason which enlightens us about the Holy Trinity, i.e. the Father, the Son and the Holy Spirit” [1]. Abstract: The article deals with the theme of the Logos` immanence in the creation. The first part includes a scientific perspective while the second, a theological one. The first evidence that the universe has a beginning dates back to the 20s of last century. Most scientists believed until then that the universe was stationary and had always existed; there are references to the big bang, string theory, M theory. The second part encompasses a perspective on the theme of the rational nature of the world which constitutes a firm foundation for dialogue between Theology and science. The logoi have a particularizing or a unifing function, and the complete unity of the logoi is realized through and by the Logos, the Word of God. The essential difference between paradigms and logoi is that the latter belong to the temporal level and to the empirical world, while the former preexist synthetically into God.The uncreated divine energies are the logoi in the action of creating and supporting of the beings.

  19. Creationism in the Grand Canyon, Texas Textbooks

    Science.gov (United States)

    Folger, Peter

    2004-01-01

    AGU President Bob Dickinson, together with presidents of six other scientific societies, have written to Joseph Alston, Superintendent of Grand Canyon National Park, pointing out that a creationist book, The Grand Canyon: A Different View, is being sold in bookstores within the borders of the park as a scientific explanation about Grand Canyon geologic history. President Dickinson's 16 December letter urges that Alston clearly separate The Grand Canyon: A Different View from books and materials that discuss the legitimate scientific understanding of the origin of the Grand Canyon. The letter warns the Park Service against giving the impression that it approves of the anti-science movement known as young-Earth creationism, or that it endorses the advancement of religious tenets disguised as science. The text of the letter is on AGU's Web site http://www.agu.org/sci_soc/policy/sci_pol.html. Also, this fall, AGU sent an alert to Texas members about efforts by intelligent design creationists aimed at weakening the teaching of biological evolution in textbooks used in Texas schools. The alert pointed scientists to a letter, drafted by AGU, together with the American Institute of Physics, the American Physical Society, the Optical Society of America, and the American Astronomical Society, that urged the Texas State Board of Education to adopt textbooks that presented only accepted, peer-reviewed science and pedagogical expertise. Over 550 scientists in Texas added their names to the letter (http://www.agu.org/sci_soc/policy/texas_textbooks.pdf ), sent to the Board of Education on 1 November prior to their vote to adopt a slate of new science textbooks. The Board voted 11-5 in favor of keeping the textbooks free of changes advocated by groups supporting intelligent design creationism.

  20. CO-CREATION IN ROMANIAN CONSUMER GOODS INDUSTRY

    Directory of Open Access Journals (Sweden)

    BUJOR Adriana

    2016-09-01

    Full Text Available Increasingly often we hear around our terms like creativity, creation, co-creation, creative industries, prosumer. The literature indicates many definitions and explanations for them, but sometimes they are hard to understand and follow as well. These terms have been around us for years, but lately their use has increased as a result of the value creation that they bring to both consumers and manufacturers. The aim of this paper is to explore and identify those Romanian businesses /industries that use co-creation as a method to empower their customers. The foreseen result is to highlight the importance of co-creation, by using online platforms, for stakeholders’ engagement in the value creation, and to which extend Romanian companies use it.

  1. "Origin," "creation," and "origin of life" some conceptual considerations.

    Science.gov (United States)

    Charpa, Ulrich

    2012-01-01

    This paper opens by drawing attention to the fact that there is some conceptual confusion with regard to "origin" and "creation." This has its historical roots in the beginnings of modern science and undoubtedly affects our positioning towards the evolutionism/creationism-debate. This article argues that there are relevant ontological, epistemological, thematic, methodological, and logical differences between "origin" and "creation." As a result, the analysis suggests keeping the usage of both concepts strictly quite separate. Creation is not simply another word for origin nor does it stand for an (from a rigid scientific point of view) awkward example of an origin. Irrespective of the apparent similarities as explanatory factors, origin and creation belong to fundamentally different types of concepts. Consequently, "origin of life" and those scientific projects connected to it present themselves as something distinct that neither competes nor meshes with thinking about creation.

  2. Probing the Correlated Triplet Pair in TIPS-Pentacene Using Transient Absorption Microscopy

    Science.gov (United States)

    Folie, Brendan D.; Ginsberg, Naomi S.

    Singlet fission, the process by which a singlet exciton splits into two triplet excitons, has been shown to increase the efficiency of photovoltaics made from organic semiconductors. Fission is believed to occur via a correlated triplet pair intermediate, but direct measurements of this state remain scant. We use polarization-resolved white light transient absorption microscopy to observe the correlated triplet pair in TIPS-Pentacene, a common model system. We are able to measure the binding energy of the triplet pair, and find that this interaction tends to diminish the triplet absorbance spectrum. Our results shed light on the kinetics and electronic structure of the correlated triplet pair, which have important implications for the creation of singlet fission based photovoltaic devices.

  3. Managing value creation in knowledge intensive business services organisations

    OpenAIRE

    Pan, Yu-Chun; Jackson, Paul; Limburg, Diana

    2015-01-01

    Value creation is essential in the Knowledge Intensive Business Service (KIBS) industry, due to its problem-solving nature. KIBS organisations need to understand their internal value creation processes as well as the complexity in the environment in order to survive and thrive. This paper investigates how value creation is managed in KIBS organisation through a case study. It then goes on to adopt Beer's Viable System Model (VSM) to propose an organisational design, namely the Value Integrati...

  4. Study of Value Co-Creation in CoPS

    OpenAIRE

    Mingli Zhang; Jianhua Ye

    2013-01-01

    Value co-creation is associated with specific investment in the context of CoPS. The feature of CoPS decides that the study of co-creation cannot execute without regarding asset specificity. This study considers that value co-creation will be associated with specific value, which is outcome of relationship value and asset specificity. Supplier and customer have a close relation, which conducts to specific investment and then it turns to obstacle for competitors. Trust, commitment and satisfac...

  5. Bank capital and liquidity creation: Granger-causality evidence

    OpenAIRE

    Horváth, Roman; Seidler, Jakub; Weill, Laurent

    2012-01-01

    We examine the relation between capital and liquidity creation. This issue is interesting because of the potential impact on liquidity creation from tighter capital requirements such as those in Basel III. We perform Granger-causality tests in a dynamic GMM panel estimator framework on an exhaustive data set of Czech banks, which mainly includes small banks from 2000 to 2010. We observe a strong expansion in liquidity creation until the financial crisis that was mainly driven by large banks. ...

  6. Pair production in classical Stueckelberg-Horwitz-Piron electrodynamics

    Science.gov (United States)

    Land, Martin

    2015-05-01

    We calculate pair production from bremsstrahlung as a classical effect in Stueckelberg-Horwitz electrodynamics. In this framework, worldlines are traced out dynamically through the evolution of events xμ(τ) parameterized by a chronological time τ that is independent of the spacetime coordinates. These events, defined in an unconstrained 8D phase space, interact through five τ-dependent gauge fields induced by the event evolution. The resulting theory differs in its underlying mechanics from conventional electromagnetism, but coincides with Maxwell theory in an equilibrium limit. In particular, the total mass-energy-momentum of particles and fields is conserved, but the mass-shell constraint is lifted from individual interacting events, so that the Feynman-Stueckelberg interpretation of pair creation/annihilation is implemented in classical mechanics. We consider a three-stage interaction which when parameterized by the laboratory clock x0 appears as (1) particle-1 scatters on a heavy nucleus to produce bremsstrahlung, (2) the radiation field produces a particle/antiparticle pair, (3) the antiparticle is annihilated with particle-2 in the presence of a second heavy nucleus. When parameterized in chronological time τ, the underlying process develops as (1) particle-2 scatters on the second nucleus and begins evolving backward in time with negative energy, (2) particle-1 scatters on the first nucleus and releases bremsstrahlung, (3) particle-2 absorbs radiation which returns it to forward time evolution with positive energy.

  7. En route to matter-antimatter pair plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Stenson, Eve V.; Hergenhahn, Uwe; Paschkowski, Norbert; Saitoh, Haruhiko; Stanja, Juliane [Max Planck Institute for Plasma Physics, Greifswald and Garching (Germany); Niemann, Holger; Sunn Pedersen, Thomas [Max Planck Institute for Plasma Physics, Greifswald and Garching (Germany); Ernst Moritz Arndt University of Greifswald, Greifswald (Germany); Schweikhard, Lutz [Ernst Moritz Arndt University of Greifswald, Greifswald (Germany); Hugenschmidt, Christoph [Technische Universitaet Muenchen, Garching (Germany); Danielson, James R.; Surko, Clifford M. [University of California, San Diego, La Jolla (United States)

    2015-05-01

    The APEX and PAX projects have as their overarching goal the laboratory creation and confinement of the world's first positron-electron pair plasma. Plasmas of this type have been the subject of hundreds of theoretical investigations and are also believed to play a role in various astrophysical environments. In order to achieve this goal in an experimentally accessible volume (e.g., 10 liters), a record number (≥ 10{sup 10}) of cold (∝ 1 eV) positrons are to be accumulated and combined with a corresponding population of electrons. Notable requirements include a high-intensity positron beam (such as NEPOMUC), a suitable magnetic confinement device for the pair plasma (such as a levitated dipole), high-efficiency tools for bridging the two (i.e., means by which the positrons can be efficiently cooled, trapped, and injected across flux surfaces), and diagnostics not only for the pair plasma, but also for the positron beam and for intermediary non-neutral plasmas. This talk will summarize the project as a whole and recent work by the APEX/PAX team on its various elements.

  8. 76 FR 3827 - Regulatory Flexibility, Small Business, and Job Creation

    Science.gov (United States)

    2011-01-21

    ... RFA emphasizes the importance of recognizing ``differences in the scale and resources of regulated... of promoting economic growth, innovation, competitiveness, and job creation. Accordingly, I hereby...

  9. The Ch’orti’ Maya Myths of Creation

    Directory of Open Access Journals (Sweden)

    Kerry Hull

    2016-03-01

    Full Text Available The Ch’orti’ Maya of southern Guatemala have a rich mythology regarding the creation of the world and the human race. In the last century, internal and external forces (religious and secular weakened the transmission of oral narratives containing elements of their creation mythology. Hull draws information from all known Ch’orti’ sources relating to the Ch’orti’ Maya view of the creation and early destruction of the world and demonstrates that the disparate, surviving details of the Ch’orti’ creation myth provide a coherent narrative that continues to inform cultural practices today.

  10. Exploring value creation from corporate-foresight activities

    DEFF Research Database (Denmark)

    Rohrbeck, René

    2012-01-01

    This paper looks at value creation from corporate futures research. Through a literature review, potential value creation is identified. This serves as guidance for an empirical investigation in which value creation is observed and linked to methods and practices. Using data from 20 case studies......, three examples of value creation are discussed in detail. In addition, cross-case analysis allowed me to identify four success criteria for corporate foresight activities: (1) foresighters committed to creating value, (2) participation of internal stakeholders, (3) analysis that follows a systemic logic...

  11. Asymmetric Ion-Pairing Catalysis

    Science.gov (United States)

    Brak, Katrien

    2014-01-01

    Charged intermediates and reagents are ubiquitous in organic transformations. The interaction of these ionic species with chiral neutral, anionic, or cationic small molecules has emerged as a powerful strategy for catalytic, enantioselective synthesis. This review describes developments in the burgeoning field of asymmetric ion-pairing catalysis with an emphasis on the insights that have been gleaned into the structural and mechanistic features that contribute to high asymmetric induction. PMID:23192886

  12. FROM THE HISTORY OF LASER CREATION

    Directory of Open Access Journals (Sweden)

    I.M. Belousova

    2014-03-01

    Full Text Available The paper briefly describes the history of formation of a new science direction - quantum electronics, associated with the discovery of masers and lasers by scientists from the USA (Ch. Townes and the USSR (N.G. Basov and A. M. Prokhorov. The world's first ruby laser designed by T. Maiman is described. Some historical events devoted to creation and research of lasers are given in which the author of the paper as well as research workers from Vavilov State Optical Institute, ITMO University and LOMO have taken direct part in the development of solid-state and gas lasers (helium-neon, photodissociation, CO2-lasers and laser optical systems. Contribution of researchers from Vavilov State Optical Institute, LOMO and ITMO University to large-scale programs on development of lasers for laser nuclear fusion, laser weapons and “Phobos” program is shown. The paper deals in brief with new issues of development and application of lasers, mainly, within the project of laser orbital space station of the future, for the conversion of solar energy into laser radiation. Description of idea of solar energy transformation by fullerene-oxygen laser is presented. The patent for it has been taken out by Vavilov State Optical Institute. Developed fullerene-oxygen-iodine laser and laser structure models for industrial applications and solar energy conversion into laser radiation are described. Parameters for hypothetical laser-optical system of the future space station are given.

  13. Philosophy for the Creation of Astronomical Images

    Science.gov (United States)

    Rector, T.; Levay, Z. G.; Frattare, L. M.; English, J.; Pu'Uohau-Pummill, K.

    2005-12-01

    The quality of modern astronomical data, the power of modern computers and the agility of current image-processing software enable the creation of high-quality images in a purely digital form. The combination of these technological advancements has created a new ability to make colour astronomical images. These programs use a layering metaphor that allows for an unlimited number of astronomical datasets to be combined in any desired colour scheme, creating an immense parameter space to be explored. A philosophy is presented on how to use scaling, colour and composition to create images that simultaneously highlight scientific detail and are aesthetically appealing. This philosophy is necessary because most datasets do not correspond to the wavelength range of sensitivity of the human eye. The use of visual grammar, defined as the elements that affect the interpretation of an image, can maximize the richness and detail in an image while maintaining scientific accuracy. By properly using visual grammar, one can imply qualities that a two-dimensional image cannot show intrinsically, such as depth, motion and energy. In addition, composition can be used to engage viewers and keep them interested for a longer period of time. The use of these techniques can result in a striking image that will effectively convey the science within the image to scientists and to the public. Details of the pictorial examples used are presented in the conference web-proceedings and webcast.

  14. Automatic creation of three-dimensional avatars

    Science.gov (United States)

    Villa-Uriol, Maria-Cruz; Sainz, Miguel; Kuester, Falko; Bagherzadeh, Nader

    2003-01-01

    Highly accurate avatars of humans promise a new level of realism in engineering and entertainment applications, including areas such as computer animated movies, computer game development interactive virtual environments and tele-presence. In order to provide high-quality avatars, new techniques for the automatic acquisition and creation are required. A framework for the capture and construction of arbitrary avatars from image data is presented in this paper. Avatars are automatically reconstructed from multiple static images of a human subject by utilizing image information to reshape a synthetic three-dimensional articulated reference model. A pipeline is presented that combines a set of hardware-accelerated stages into one seamless system. Primary stages in this pipeline include pose estimation, skeleton fitting, body part segmentation, geometry construction and coloring, leading to avatars that can be animated and included into interactive environments. The presented system removes traditional constraints in the initial pose of the captured subject by using silhouette-based modification techniques in combination with a reference model. Results can be obtained in near-real time with very limited user intervention.

  15. Quantum graviton creation in a model universe

    Science.gov (United States)

    Berger, B. K.

    1974-01-01

    Consideration of the mechanism of production of gravitons in the empty, anisotropic, spatially inhomogeneous Gowdy three-torus cosmology. The Gowdy cosmology is an exact solution of the vacuum Einstein equations and is obtained as a generalization of the homogeneous empty Bianchi Type I (Kasner) cosmology by permitting the metric components to depend on one of the space variables in addition to time. The Hamiltonian methods of Arnowitt, Deser, and Misner are employed to identify the dynamical variables which are to be quantized. The WKB regime solution is identical to that found by Doroshkevich, Zel'dovich, and Novikov (DZN) for a universe containing collisionless anisotropic radiation. Using a procedure similar to that of Parker (1971) or Zel'dovich and Starobinskii (1971) for defining quantum number, it is found that the DZN large-time radiation consists of quanta (gravitons) created from an initial vacuum. The quantum behavior is much like the semiclassical enhancement of quantum number with the added feature of creation of quanta from vacuum fluctuations.

  16. ITER Creation Safety File Expertise Results

    Science.gov (United States)

    Perrault, D.

    2013-06-01

    In March 2010, the ITER operator delivered the facility safety file to the French "Autorité de Sûreté Nucléaire" (ASN) as part of its request for the creation decree, legally necessary before building works can begin on the site. The French "Institut de Radioprotection et de Sûreté Nucléaire" (IRSN), in support to the ASN, recently completed its expertise of the safety measures proposed for ITER, on the basis of this file and of additional technical documents from the operator. This paper presents the IRSN's main conclusions. In particular, they focus on the radioactive materials involved, the safety and radiation protection demonstration (suitability of risk management measures…), foreseeable accidents, building and safety important component design and, finally, wastes and effluents to be produced. This assessment was just the first legally-required step in on-going safety monitoring of the ITER project, which will include other complete regulatory re-evaluations.

  17. Bohr's Creation of his Quantum Atom

    Science.gov (United States)

    Heilbron, John

    2013-04-01

    Fresh letters throw new light on the content and state of Bohr's mind before and during his creation of the quantum atom. His mental furniture then included the atomic models of the English school, the quantum puzzles of Continental theorists, and the results of his own studies of the electron theory of metals. It also included the poetry of Goethe, plays of Ibsen and Shakespeare, novels of Dickens, and rhapsodies of Kierkegaard and Carlyle. The mind that held these diverse ingredients together oscillated between enthusiasm and dejection during the year in which Bohr took up the problem of atomic structure. He spent most of that year in England, which separated him for extended periods from his close-knit family and friends. Correspondence with his fianc'ee, Margrethe Nørlund, soon to be published, reports his ups and downs as he adjusted to J.J. Thomson, Ernest Rutherford, the English language, and the uneven course of his work. In helping to smooth out his moods, Margrethe played an important and perhaps an enabling role in his creative process.

  18. RELATIONAL MECHANISMS IN INNOVATION CO-CREATION

    Directory of Open Access Journals (Sweden)

    Rodica Boier

    2014-12-01

    Full Text Available Increasingly, producers and customers establish relationships to mutually undertake the development of an innovative product. Consequently, it will be always of interest for an innovative company to know the degree to which different related suppliers are willing to form partnerships by participating in its new product development process. Several managerial implications flow from the link between relationship marketing and innovation processes, ranging from tactical product-related decisions to strategic competitor-related decisions, usually made in a relatively short period of time. Dedicated customer relationship systems track the interactions with customers and improve the flow of ideas for new products. When trying to develop long-term customer relationships, the ability to provide superior value to stakeholders is a must. Through carefully conducted relationships, customers are linked with the innovation company during the entire innovation process, and create a space for mutual understanding, learning and value co-creation. In order to co-create business value through online, also combined with offline innovation-related activities, customer orientation should be implemented throughout the organization – its culture, their systems, including the whole range of interactions.

  19. Opening the black box: knowledge creation in data teams

    NARCIS (Netherlands)

    Hubers, Mireille Desirée; Poortman, Cindy Louise; Schildkamp, Kim; Pieters, Julius Marie; Handelzalts, Adam

    2016-01-01

    Purpose – In this study, Nonaka and Takeuchi’s socialization, externalization, combination and internalization (SECI) model of knowledge creation is used to gain insight into the process of knowledge creation in data teams. These teams are composed of school leaders and teachers, who work together

  20. Value co-creation in service interactions: dimensions and antecedents

    NARCIS (Netherlands)

    Neghina, C.; Caniëls, M.C.J.; Bloemer, J.M.M.; Birgelen, M.J.H. van

    2013-01-01

    The purpose of this article is to further develop the conceptualization of value co-creation and discuss its dimensions and antecedents. We propose that in service interactions, value co-creation should be understood as a joint collaborative activity between service employees and customers

  1. The Genesis Account of Creation and its Relationship to Cosmogony.

    African Journals Online (AJOL)

    This paper concerns itself with the issue of the account of creation and its relationship to cosmogony. In this jet age when western education has broadened people's mind, there is a strong desire to know the true origin of man and the universe. It goes a step further to highlight various concepts of creation, pointing out their ...

  2. Co-creation, Prevailing Streams and a Future Design Trajectory

    DEFF Research Database (Denmark)

    Degnegaard, Rex

    2014-01-01

    Co-creation as a concept has won terrain over the past 10 years. In practice as well as in literature, co-creation is climbing the agenda in relation to contemporary opportunities and challenges within management, organisation design and change initiatives. This paper aims to build an overview of...

  3. The relation between creation and salvation in the Trinitarian ...

    African Journals Online (AJOL)

    2013-02-07

    Feb 7, 2013 ... We will play with star clusters and black holes with God in sheer enjoyment. This understanding of creation's true teleology and place in God brings a moral perspective to our current relation to creation. Jenson (1999) says that when we acknowledge our place in God, we may perceive a better way: we may ...

  4. Interactive creation of virtual worlds using procedural sketching

    NARCIS (Netherlands)

    Smelik, R.M.; Tutenel, T.; Kraker, K.J. de; Bidarra, R.

    2010-01-01

    Procedural modelling is an attractive alternative to cut down the costs of manual content creation for virtual worlds. We discuss our declarative modelling approach to the creation of 3D virtual worlds, which integrates a variety of procedural techniques in order to enable a non-specialist user to

  5. Legal and Judicial Problems in Mandating Equal Time for Creationism.

    Science.gov (United States)

    Skoog, Gerald

    This paper, presented at the annual meeting of the National Association of Biology Teachers, is focused on legal and judicial problems in mandating equal time for creationism. Past events provide evidence that legislation, policies, and local resolutions that require science textbooks and curricula to include the Genesis account of creation are…

  6. Should Creation Be Included in the Biology Curriculum?

    Science.gov (United States)

    Skoog, Gerald

    The author discusses the activities and goals of advocates of creation science as these persons and groups work to bring about the teaching of creationism in high school science courses in which evolution is taught. It is the author's belief that the anti-evolutionism movement was stimulated by the science curriculum improvement activities of the…

  7. 12 CFR 611.1040 - Creation of new associations.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Creation of new associations. 611.1040 Section..., Consolidations and Charter Amendments § 611.1040 Creation of new associations. Any application for the issuance of a charter to a new production credit association or Federal land bank association shall meet the...

  8. Strong-field Breit–Wheeler pair production in two consecutive laser pulses with variable time delay

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Martin J.A.; Müller, Carsten, E-mail: c.mueller@tp1.uni-duesseldorf.de

    2017-03-10

    Photoproduction of electron–positron pairs by the strong-field Breit–Wheeler process in an intense laser field is studied. The laser field is assumed to consist of two consecutive short pulses, with a variable time delay in between. By numerical calculations within the framework of scalar quantum electrodynamics, we demonstrate that the time delay exerts a strong impact on the pair-creation probability. For the case when both pulses are identical, the effect is traced back to the relative quantum phase of the interfering S-matrix amplitudes and explained within a simplified analytical model. Conversely, when the two laser pulses differ from each other, the pair-creation probability depends not only on the time delay but, in general, also on the temporal order of the pulses.

  9. Charge Aspects of Composite Pair Superconductivity

    Science.gov (United States)

    Flint, Rebecca

    2014-03-01

    Conventional Cooper pairs form from well-defined electronic quasiparticles, making the internal structure of the pair irrelevant. However, in the 115 family of superconductors, the heavy electrons are forming as they pair and the internal pair structure becomes as important as the pairing mechanism. Conventional spin fluctuation mediated pairing cannot capture the direct transition from incoherent local moments to heavy fermion superconductivity, but the formation of composite pairs favored by the two channel Kondo effect can. These composite pairs are local d-wave pairs formed by two conduction electrons in orthogonal Kondo channels screening the same local moment. Composite pairing shares the same symmetries as magnetically mediated pairing, however, only composite pairing necessarily involves a redistribution of charge within the unit cell originating from the internal pair structure, both as a monopole (valence change) and a quadrupole effect. This redistribution will onset sharply at the superconducting transition temperature. A smoking gun test for composite pairing is therefore a sharp signature at Tc - for example, a cusp in the Mossbauer isomer shift in NpPd5Al2 or in the NQR shift in (Ce,Pu)CoIn5.

  10. Squark pair production at NLO

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, Michael; Pellen, Mathieu [RWTH Aachen University, Institut fuer Theoretische Teilchenphysik und Kosmologie (Germany); Hangst, Christian; Muehlleitner, Margarete [KIT, Institut fuer Theoretische Physik (Germany); Popenda, Eva; Spira, Michael [PSI, Theory Group LTP (Switzerland)

    2013-07-01

    A lot of effort is and will be put in the search for supersymmetric particles at the LHC. For the interpretation of the experimental data precise theoretical predictions are crucial. The work presented in the talk contributes to this effort by providing NLO corrections to the pair production of squarks of the first two generations in a flexible partonic Monte Carlo program. In contrast to previous works no assumptions regarding the squark masses have been made and the different subchannels have been treated independently. The Monte Carlo framework allows investigating the impact of the supersymmetric QCD corrections at NLO on arbitrary distributions.

  11. Lost Chevalier Pairs - A Followup

    Science.gov (United States)

    2012-01-01

    correct, but the true 19 position angle was 180° minus the Chevalier value. The initial conclusion was that Chevalier had made a trigonometry error... trigonometry /plate errors, there was an additional 10’ error in Chevalier’s declination, due to an error in applying the y offset. Berk6 was unable to find...a match. After correcting for the plate center and trigonometry /plate errors, this pair was found to match 19498+2324 = J 496AB, as noted by Berko

  12. Coisotropic Submanifolds and Dual Pairs

    Science.gov (United States)

    Cattaneo, Alberto S.

    2014-03-01

    The Poisson sigma model is a widely studied two-dimensional topological field theory. This note shows that boundary conditions for the Poisson sigma model are related to coisotropic submanifolds (a result announced in [math.QA/0309180]) and that the corresponding reduced phase space is a (possibly singular) dual pair between the reduced spaces of the given two coisotropic submanifolds. In addition the generalization to a more general tensor field is considered and it is shown that the theory produces Lagrangian evolution relations if and only if the tensor field is Poisson.

  13. Endocrine factors of pair bonding.

    Science.gov (United States)

    Stárka, L

    2007-01-01

    Throughout literature--fiction and poetry, fine arts and music--falling in love and enjoying romantic love plays a central role. While several psychosocial conceptions of pair attachment consider the participation of hormones, human endocrinology has dealt with this theme only marginally. According to some authors in addictology, falling in love shows some signs of hormonal response to stressors with changes in dopamine and serotonin signalling and neurotrophin (transforming growth factor b) concentration. Endorphins, oxytocin and vasopressin may play a role during the later phases of love. However, proof of hormonal events associated with love in humans has, until recently, been lacking.

  14. DNA Aptamer Generation by Genetic Alphabet Expansion SELEX (ExSELEX) Using an Unnatural Base Pair System.

    Science.gov (United States)

    Kimoto, Michiko; Matsunaga, Ken-ichiro; Hirao, Ichiro

    2016-01-01

    Genetic alphabet expansion of DNA using unnatural base pair systems is expected to provide a wide variety of novel tools and methods. Recent rapid progress in this area has enabled the creation of several types of unnatural base pairs that function as a third base pair in polymerase reactions. Presently, a major topic is whether the genetic alphabet expansion system actually increases nucleic acid functionalities. We recently applied our unnatural base pair system to in vitro selection (SELEX), using a DNA library containing four natural bases and an unnatural base, and succeeded in the generation of high-affinity DNA aptamers that specifically bind to target proteins. Only a few hydrophobic unnatural bases greatly augmented the affinity of the aptamers. Here, we describe a new approach (genetic alphabet Expansion SELEX, ExSELEX), using our hydrophobic unnatural base pair system for high affinity DNA aptamer generation.

  15. Innovation and Entrepreneurship: The Necessary Conditions of Value Creation

    Directory of Open Access Journals (Sweden)

    Brian Barnard

    2017-10-01

    Full Text Available The necessary conditions of value creation are considered from the vantage point of innovation and entrepreneurship. Both demand side (basic needs, customer perceived value, and customer satisfaction and supply side (science, technology, and knowledge considerations of value creation are examined. The relationships between value creation and basic needs, customer perceived value, and knowledge are further examined. Although a number of factors are identified that impact value, only four are seen as primary factors of value: price, benefit, satisfaction, and experience. The innovator and entrepreneur can create value, and quantify the uniqueness of their value offerings, through these four primary factors. The study concludes that, on the demand side, basic needs may be an indirect driver of value creation, and customer perceived value as concept may be useful in the context of value creation. At the same time, it is believed that the four factors – price, benefit, satisfaction, and experience – can significantly explain value creation. On the supply side, innovation as the driver of value creation, is not necessarily confined to science and technology – business knowledge and acumen is an important avenue. In addition to existing knowledge and experience, factors like orientation (interests, passion, drive and involvement also explain opportunity recognition.

  16. The potential of shared value creation: a theoretical analysis

    Directory of Open Access Journals (Sweden)

    Victor Danciu

    2016-06-01

    Full Text Available The urgent issues economy, environment and society are facing need new approaches which allow a well-balanced sharing of value created by the economy. A step forward is the concept of shared value creation. This paper aims to analyze the main features, the content of strategy of shared value creation and to propose the social innovation as main strategic way of shared value creation. At the beginning, the drivers and challenges of shared value creation are investigated in a systematized manner, in order to better understand why this new way of doing business is needed. Then, the concept and the three levels of shared value creation are investigated as sources of economic, environmental and social benefits that a business creates. These benefits depend on how efficient and diligent the company works. We are advancing the social innovation as main strategy having the greatest potential to create value with economic, environmental and social benefits. Finally, a framework for measurement of shared value creation is included. This framework is aiming at giving a tool for checking up the potential the shared value creation has for solving environmental and social issues.

  17. The Framework of Knowledge Creation for Online Learning Environments

    Directory of Open Access Journals (Sweden)

    Hsiu-Mei Huang

    2004-02-01

    Full Text Available Abstract: In today’s competitive global economy characterized by knowledge acquisition, the concept of knowledge management has become increasingly prevalent in academic and business practices. Knowledge creation is an important factor and remains a source of competitive advantage over knowledge management. Information technology facilitates knowledge management practices by disseminating knowledge and making codified knowledge retrievable. Thus, this paper proposes a framework of knowledge creation in online learning environments. In addition, the features and issues of knowledge creation in these environments are discussed.

  18. SMEs’ Wealth Creation Model of an Emerging Economy

    Directory of Open Access Journals (Sweden)

    Olalekan Usiobaifo ASIKHIA

    2016-05-01

    Full Text Available This article synthesizes the evidence on SMEs’ wealth creation in an emerging economy, paying particular attention to human resource/expertise, technology adoption, innovation and creativity, unit economies, organizational infrastructure and strategy as determinants of SMEs’ wealth creation. A survey of 581 Nigerian SMEs was conducted and the data was analysed and tested using multiple regression and structural equation modelling. The findings revealed Human resource/CEOs expertise as the highest contributory factor to wealth creation within the firm in the industrial and the commercial sectors. The relevant domains were modelled and relevant policy adjustments were suggested.

  19. Knowledge Creation in International Joint Ventures in Emerging Economies

    DEFF Research Database (Denmark)

    Nielsen, Ulrik B.

    demonstrated that creation of new IJV-specific knowledge can be imperative to performance while Pak, Ra, and Lee (2015) demonstrated that IJV parents can become beneficiaries of collaborative sensing and seize the market opportunities (Johanson & Vahlne, 2006). However, inter-organizational knowledge creation...... processes in IJVs have rarely been examined (Pak et al., 2015) especially not in the context of IJVs in emerging economies. This paucity of studies concerning knowledge creation and inter-organizational learning in IJVs have been noted at a critical research gap in the literature (J.-Y. Park, Ha, & Lew...

  20. Value Creation in the Context of Sustainable Corporate Social Responsibility

    Directory of Open Access Journals (Sweden)

    Šmida Ľubomír

    2014-12-01

    Full Text Available Under the influence of the new rules of the economy and the society, companies are achieving a notional line of a necessary change in the approach to creating new value, wealth. Implementation of changes in the system of wealth creation requires a review of existing assumptions of unlimited growth of the global economy and wealth creation in the environment accepting economic interests, society and the environment as a holistic unit. The main purpose of this paper is the clarification of a new requirements for business, presentation of the questionnaire survey Sustainable Corporate Social Responsibility and inform on value creation in the context of Sustainable Corporate Social Responsibility.

  1. Value Creation in the Context of Sustainable Corporate Social Responsibility

    Science.gov (United States)

    Šmida, Ľubomír; Sakál, Peter

    2014-12-01

    Under the influence of the new rules of the economy and the society, companies are achieving a notional line of a necessary change in the approach to creating new value, wealth. Implementation of changes in the system of wealth creation requires a review of existing assumptions of unlimited growth of the global economy and wealth creation in the environment accepting economic interests, society and the environment as a holistic unit. The main purpose of this paper is the clarification of a new requirements for business, presentation of the questionnaire survey Sustainable Corporate Social Responsibility and inform on value creation in the context of Sustainable Corporate Social Responsibility.

  2. Gravitational particle creation in a stiff matter dominated universe

    Science.gov (United States)

    Lankinen, Juho; Vilja, Iiro

    2017-08-01

    A scenario for gravitational particle creation in a stiff matter dominated flat Friedmann-Robertson-Walker universe is presented. The primary creation of scalar particles is calculated using quantum field theory in curved spacetime and it is found to be strongly dependent on the scalar mass and the expansion parameter of the universe. The particle creation is most effective for a very massive scalar field and large expansion parameter. We demonstrate the phenomenon by applying it to cosmological toy model scenario, where secondary particles are created by the scalar field decay.

  3. Pair distribution function computed tomography.

    Science.gov (United States)

    Jacques, Simon D M; Di Michiel, Marco; Kimber, Simon A J; Yang, Xiaohao; Cernik, Robert J; Beale, Andrew M; Billinge, Simon J L

    2013-01-01

    An emerging theme of modern composites and devices is the coupling of nanostructural properties of materials with their targeted arrangement at the microscale. Of the imaging techniques developed that provide insight into such designer materials and devices, those based on diffraction are particularly useful. However, to date, these have been heavily restrictive, providing information only on materials that exhibit high crystallographic ordering. Here we describe a method that uses a combination of X-ray atomic pair distribution function analysis and computed tomography to overcome this limitation. It allows the structure of nanocrystalline and amorphous materials to be identified, quantified and mapped. We demonstrate the method with a phantom object and subsequently apply it to resolving, in situ, the physicochemical states of a heterogeneous catalyst system. The method may have potential impact across a range of disciplines from materials science, biomaterials, geology, environmental science, palaeontology and cultural heritage to health.

  4. Universalities of Triplet Pairing in Neutron Matter

    OpenAIRE

    Khodel, V. A.; Khodel, V. V.; Clark, J. W.

    1998-01-01

    The fundamental structure of the full set of solutions of the BCS $^3 P_2$ pairing problem in neutron matter is established. The relations between different spin-angle components in these solutions are shown to be practically independent of density, temperature, and the specific form of the pairing interaction. The spectrum of pairing energies is found to be highly degenerate.

  5. Electron-hole quantum physics in ZnO

    NARCIS (Netherlands)

    Versteegh, M.A.M.|info:eu-repo/dai/nl/304829935

    2011-01-01

    This dissertation describes several new aspects of the quantum physics of electrons and holes in zinc oxide (ZnO), including a few possible applications. Zinc oxide is a II-VI semiconductor with a direct band gap in the ultraviolet. Experimental and theoretical studies have been performed, both on

  6. Electron-hole confinement symmetry in silicon quantum dots

    NARCIS (Netherlands)

    Müller, F.; Mueller, Filipp; Konstantaras, Georgios; Spruijtenburg, P.C.; van der Wiel, Wilfred Gerard; Zwanenburg, Floris Arnoud

    2015-01-01

    We report electrical transport measurements on a gate-defined ambipolar quantum dot in intrinsic silicon. The ambipolarity allows its operation as either an electron or a hole quantum dot of which we change the dot occupancy by 20 charge carriers in each regime. Electron−hole confinement symmetry is

  7. Antiferromagnetic Skyrmion: Stability, Creation and Manipulation.

    Science.gov (United States)

    Zhang, Xichao; Zhou, Yan; Ezawa, Motohiko

    2016-04-21

    Magnetic skyrmions are particle-like topological excitations in ferromagnets, which have the topo-logical number Q = ± 1, and hence show the skyrmion Hall effect (SkHE) due to the Magnus force effect originating from the topology. Here, we propose the counterpart of the magnetic skyrmion in the antiferromagnetic (AFM) system, that is, the AFM skyrmion, which is topologically protected but without showing the SkHE. Two approaches for creating the AFM skyrmion have been described based on micromagnetic lattice simulations: (i) by injecting a vertical spin-polarized current to a nanodisk with the AFM ground state; (ii) by converting an AFM domain-wall pair in a nanowire junction. It is demonstrated that the AFM skyrmion, driven by the spin-polarized current, can move straightly over long distance, benefiting from the absence of the SkHE. Our results will open a new strategy on designing the novel spintronic devices based on AFM materials.

  8. Macroeconomic policy for employment creation: The case of Malawi

    OpenAIRE

    Deraniyagala, Sonali; Kaluwa, Ben

    2011-01-01

    This paper looks at policies for achieving full and productive employment in Malawi. The polices are consistent with ILO's Global Employment Agenda. Monetary and fiscal policies consistent with employment creation is proposed.

  9. Creation, Its Processes, and Significance (Samkhya Evolution and Involution

    Directory of Open Access Journals (Sweden)

    Pratibha Gramann

    2015-11-01

    Full Text Available Science, religions, and cultural traditions develop theories and creative descriptions about the origin of the universe and meaning of life. These theories have both similarities and differences regarding the cause and effect of creation, and life as human beings know it. Religions and cultural traditions primarily adhere to a personal God as creator and ruler. Science has gone in the opposite direction of denying the existence of a God. A definitive cause of creation has not been scientifically found. Science may find a comparable, suitable match in the ancient thought of Samkhya, written in the 500-800 BC time. Samkhya is probably the first complete philosophical description of the origin and evolution of creation. The three basic energetics of Samkhya are comparable to the basic energies of physics. This paper addresses the hypothesis that the evolution and origin of creation stem from the 3 energies gunas of materiality prakriti described in ancient Samkhya.

  10. CONCEPTUAL APPROACHES TO THE CREATION OF UNIVERSITY ELECTRONIC LIBRARIES

    Directory of Open Access Journals (Sweden)

    P. M. Lapo

    2013-01-01

    Full Text Available The peculiarities of informatization in education, conceptual approaches to the creation of electronic libraries, as well as the content and the rating of the electronic library of Belarusian State University are considered.

  11. The Creation of Districts and Constituencies in Ghana: Some ...

    African Journals Online (AJOL)

    multi-constituency districts which were carved up on the basis of the existing constituencies ... criteria for the creation of constituencies and mandates the Electoral ..... and collective decision-making based on consensus at the grassroots" and.

  12. Creationism/Evolution: The Case AGAINST "Equal Time".

    Science.gov (United States)

    Brush, Stephen G.

    2000-01-01

    Describes the approaches of both creationism and evolution. Recommends that biologists take their case to the public. Includes a National Science Teachers Association (NSTA) Position Statement on the issue. First published in 1981. (YDS)

  13. The threat from creationism to the rational teaching of biology.

    Science.gov (United States)

    Cornish-Bowden, Athel; Cárdenas, María Luz

    2007-01-01

    Most biologists outside the USA and a few other countries, like Australia and Canada, are under the impression that the threat to the teaching of biology represented by creationism does not concern them directly. This is unfortunately no longer true: the recent growth of creationism, especially in its pseudo-scientific manifestation known as "intelligent design", has been obvious in several countries of Western Europe, especially the UK, Germany and Poland, and it is beginning to be noticeable in Brazil, and maybe elsewhere in Latin America. The problem is complicated by the fact that there are not just two possibilities, evolution and creationism, because creationism comes in various incompatible varieties. Turkey is now a major source of creationist propaganda outside the USA, and is especially significant in relation to its influence on Muslim populations in Europe. The time for biologists to address the creationist threat is now.

  14. Hierarchical mask creation for intelligent image coding using saliency maps

    Directory of Open Access Journals (Sweden)

    Radoslav Vargic

    2016-12-01

    Full Text Available In this paper we analyze basic mask creation methods for intelligent image coding using saliency maps. For saliency maps based image coding we use specific extension of SPIHT algorithm called SM SPIHT related to region of interest encoding but extending this approach further, ending with individual weight of importance for each pixel in image using the form of saliency map. This approach is proved to be effective. In this article we analyze impact of different basic hierarchical mask creation methods, which have impact on error separation between salient and not salient parts of the image. The results indicate that proposed mask creation method outperforms JPEG2000 based mask tree creation method.

  15. Wetland creation and restoration : description and summary of the literature

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides a hard copy of the bibliographic information contained in the digital Wetland Creation/Restoration Data Base. One thousand one hundred data base...

  16. Factors influencing the creation of the goodwill of enterpjrises

    Directory of Open Access Journals (Sweden)

    Vodzinský Vladimír

    1999-03-01

    Full Text Available The importance of the goodwill creation from the viewpoint of achieving the goals of enterprises is permanently growing in the transi-tive societies. In this paper, factors are analyzed that have to be respected by managing subject of the enterprises during the goodwill creation. But, problems that cause the goodwill misrepresentation (when it is evaluated by standard criteria are also analyzed.

  17. Creation of electromechanical device for electric vehicle traction

    Directory of Open Access Journals (Sweden)

    Денис Юрьевич Зубенко

    2016-10-01

    Full Text Available The problems of creation of electromechanical device for electric vehicle traction are considered in the article. The aim of creation this design are the replacement of the internal combustion engine on electromechanical device. For this electromechanical device are constructed model, which describe processes that occur in the electric drive of electromechanical device. Characteristics of the main modes of motion were recorded. The introduction of electromechanical device will reduce the level of emissions and reduce noise in the cities

  18. Is Emergent Universe a Consequence of Particle Creation Process?

    OpenAIRE

    Chakraborty, Subenoy

    2014-01-01

    A model of an emergent universe is formulated using the mechanism of particle creation. Here the universe is considered as a non-equilibrium thermodynamical system with dissipation due to particle creation mechanism. The universe is chosen as spatially flat FRW space–time and the cosmic substratum is chosen as perfect fluid with barotropic equation of state. Both first and second order deviations from equilibrium prescription are considered and it is found that the scenario of emergent univer...

  19. On relativistic particle creation in Bose-Einstein condensates

    OpenAIRE

    Sabín, Carlos; Fuentes, Ivette

    2014-01-01

    We show that particle creation of Bogoliubov modes in a Bose-Einstein condensate due to the accelerated motion of the trap is a genuinely relativistic effect. To this end we show that Bogoliubov modes can be described by a time rescaling of the Minkowski metric. A consequence of this is that Rindler transformations are perceived by the phonons as generalised Rindler transformations where the speed of light is replaced by the speed of sound, enhancing particle creation at small velocities. Sin...

  20. An Expanded Model of Distributed Leadership in Organizational Knowledge Creation

    OpenAIRE

    Cannatelli, B.; Smith, B. J.; Giudici, A.; Jones, J; Conger, M.

    2016-01-01

    Based on a three-year qualitative, longitudinal case study of a social venture partnership, we extend the understanding of distributed leadership in organizational knowledge creation. We develop an expanded model of distributed leadership that identifies the antecedents, different forms, and enablers of distributed leadership in knowledge creation. Our findings move beyond a static and monolithic understanding of distributed leadership to illustrate how an expanded model informs the situation...

  1. A Social Vision for Value Co-creation in Design

    Directory of Open Access Journals (Sweden)

    George Simons

    2009-11-01

    Full Text Available The Cluetrain Manifesto was introduced in 1999, calling for a powerful global conversation between companies and the people they serve. Since then, the conversation has started and is finally gaining momentum. Co-creation is the buzzword of the day to describe the various types of conversations that are taking place. But the conversation has multiple perspectives. It can be applied to multiple domains ranging from sales tactics and branding contests to strategic, human-centered means of affecting social transformation. In this article we try to articulate a vision for value co-creation by focusing on its social aspects. It is our hope that such social vision will contribute to existing perspectives so that future conversations can take place in a more productive way. The suggested framework organizes the seemingly disparate applications, comparing the mindset, goals and results of three types of value co-creation: monetary, use/experience and social. Although these three types of value co-creation are all relevant, we believe that the social type of value provides a real opportunity for significant social change. However, the rules of engagement for this type of co-creation are particularly challenging. Participation must be face-to-face to allow for real-time interaction to take place. Empathy for the people who will be affected by change is key. Visualization of the collective assets is essential. And having the appropriate mindset about co-creation is the single most important component for success.

  2. Stakeholder Theory and Value Creation Models in Brazilian Firms

    Directory of Open Access Journals (Sweden)

    Natalia Giugni Vidal

    2015-09-01

    Full Text Available Objective – The purpose of this study is to understand how top Brazilian firms think about and communicate value creation to their stakeholders. Design/methodology/approach – We use qualitative content analysis methodology to analyze the sustainability or annual integrated reports of the top 25 Brazilian firms by sales revenue. Findings – Based on our analysis, these firms were classified into three main types of stakeholder value creation models: narrow, broad, or transitioning from narrow to broad. We find that many of the firms in our sample are in a transition state between narrow and broad stakeholder value creation models. We also identify seven areas of concentration discussed by firms in creating value for stakeholders: better stakeholder relationships, better work environment, environmental preservation, increased customer base, local development, reputation, and stakeholder dialogue. Practical implications – This study shows a trend towards broader stakeholder value creation models in Brazilian firms. The findings of this study may inform practitioners interested in broadening their value creation models. Originality/value – This study adds to the discussion of stakeholder theory in the Brazilian context by understanding variations in value creation orientation in Brazil.

  3. Looking and listening for learning in arts- and humanities-based creations.

    Science.gov (United States)

    Varpio, Lara; Grassau, Pamela; Hall, Pippa

    2017-02-01

    The arts and humanities are gradually gaining a foothold in health professions education as a means of supporting the development of future clinicians who are compassionate, critical and reflexive thinkers, while also strengthening clinical skills and practices that emphasise patient-centredness, collaboration and interprofessional practices. Assignments that tap into trainee creativity are increasingly used both to prepare learners for the demands of clinical work and to understand the personal and professional challenges learners face in these contexts. Health professions educators need methods for interpreting these creations in order to understand each learner's expressions. This paper describes two theoretical frameworks that can be used to understand trainees' unique learning experiences as they are expressed in arts- and humanities-based creations. The authors introduce the philosophical underpinnings and interpretation procedures of two theoretical frameworks that enable educators to 'hear' and 'see' the multilayered expressions embedded within arts- and humanities-based student creations: Gilligan's Listening Guide and Kress and van Leeuwen's approach to visual rhetoric. To illustrate how these frameworks can be used, the authors apply them to two creative summaries that learners made as part of a humanities-informed, interprofessional education intervention that took place in a non-acute-care teaching hospital. The interpretations of two creative summaries, a poem and a pair of paintings, highlight how applying these theoretical frameworks can offer important insights into learners' experiences. This cross-cutting edge paper describes how the Listening Guide and visual rhetoric can help health professions educators listen to and read the arts- and humanities-based creative expressions made by learners. Insights gained from these interpretations can advance the understanding of students' personal experiences in different learning environments and can

  4. Report on Pairing-based Cryptography.

    Science.gov (United States)

    Moody, Dustin; Peralta, Rene; Perlner, Ray; Regenscheid, Andrew; Roginsky, Allen; Chen, Lily

    2015-01-01

    This report summarizes study results on pairing-based cryptography. The main purpose of the study is to form NIST's position on standardizing and recommending pairing-based cryptography schemes currently published in research literature and standardized in other standard bodies. The report reviews the mathematical background of pairings. This includes topics such as pairing-friendly elliptic curves and how to compute various pairings. It includes a brief introduction to existing identity-based encryption (IBE) schemes and other cryptographic schemes using pairing technology. The report provides a complete study of the current status of standard activities on pairing-based cryptographic schemes. It explores different application scenarios for pairing-based cryptography schemes. As an important aspect of adopting pairing-based schemes, the report also considers the challenges inherent in validation testing of cryptographic algorithms and modules. Based on the study, the report suggests an approach for including pairing-based cryptography schemes in the NIST cryptographic toolkit. The report also outlines several questions that will require further study if this approach is followed.

  5. Readmission for dehydration or renal failure after ileostomy creation.

    Science.gov (United States)

    Paquette, Ian M; Solan, Patrick; Rafferty, Janice F; Ferguson, Martha A; Davis, Bradley R

    2013-08-01

    Ileostomy creation is a commonly performed operation in colorectal surgery; however, many patients develop complications such as dehydration postoperatively. Dehydration is often severe enough to warrant hospital readmission and may result in renal failure. The true incidence of this complication has not been well described. The aim of this study was to identify the rate of hospital readmission secondary to dehydration or renal failure within 30 days of ileostomy creation. Retrospective review of all patients undergoing ileostomy creation from 2007 to 2011 in a single colorectal practice of 4 surgeons was performed. Charts were reviewed to identify patients readmitted for dehydration or renal failure within 30 days of operation. Data were then analyzed to identify predictors of readmission, dehydration, and renal failure. Subset analysis compared patients readmitted with simple dehydration versus patients with renal failure. Two hundred one patients undergoing colorectal operations that included ileostomy creation within a 4-year period at a single institution for a variety of indications were included. The primary outcome measured was readmission for dehydration or renal failure. We observed a 17% 30-day readmission rate for dehydration or renal failure following ileostomy creation. Age greater than 50 was identified as an independent predictor of readmission with renal failure, whereas IPAA was predictive of readmission for simple dehydration, but not renal failure. Patients admitted with renal failure had significantly longer hospital stays and median hospital charges after readmission in comparison with patients admitted with simple dehydration. This study was limited by its retrospective nature and its limited sample size. Hospital readmission due to dehydration or renal failure following ileostomy creation is common, with age >50 being the strongest predictor for renal failure. Appropriate strategies to decrease dehydration and renal failure following

  6. Ordered pairing in liquid metallic hydrogen

    Science.gov (United States)

    Carlsson, A. E.; Ashcroft, N. W.

    1983-01-01

    We study two possible types of pairing involving the protons of a proposed low-temperature liquid phase metallic hydrogen. Electron-proton pairing, which can result in an insulating phase, is investigated by using an approximate solution of an Eliashberg-type equation for the anomalous self-energy. A very low estimate of the transition temperature is obtained by including proton correlations in the effective interaction. For proton-proton pairing, we derive a new proton pair potential based on the Abrikosov wave function. This potential includes the electron-proton interaction to all orders and has a much larger well depth than is obtained with linear screening methods. This suggests the possibility of either a superfluid paired phase analogous to that in He-3, or alternatively a phase with true molecular pairing.

  7. An Entropic Approach for Pair Trading

    Directory of Open Access Journals (Sweden)

    Daisuke Yoshikawa

    2017-06-01

    Full Text Available In this paper, we derive the optimal boundary for pair trading. This boundary defines the points of entry into or exit from the market for a given stock pair. However, if the assumed model contains uncertainty, the resulting boundary could result in large losses. To avoid this, we develop a more robust strategy by accounting for the model uncertainty. To incorporate the model uncertainty, we use the relative entropy as a penalty function in the expected profit from pair trading.

  8. Total scattering analysis of cation coordination and vacancy pair distribution in Yb substituted δ-Bi2O3.

    Science.gov (United States)

    Leszczynska, M; Liu, X; Wrobel, W; Malys, M; Norberg, S T; Hull, S; Krok, F; Abrahams, I

    2013-11-13

    Reverse Monte Carlo (RMC) modelling of neutron total scattering data, combined with conventional Rietveld analysis of x-ray and neutron data, has been used to describe the cation coordination environments and vacancy pair distribution in the oxide ion conducting electrolyte Bi3YbO6. The thermal variation of the cubic fluorite unit cell volume, monitored by variable temperature x-ray and neutron experiments, reveals significant curvature, which is explained by changes in the oxide ion distribution. There is a significant increase in tetrahedral oxide ion vacancy concentration relative to δ-Bi2O3, due to the creation of Frenkel defects associated with the Yb(3+) cation. The tetrahedral oxide ion vacancy concentration increases from room temperature to 800 °C, but little change is observed in the vacancy pair distribution with temperature. The vacancy pair distributions at both temperatures are consistent with a favouring of [100] vacancy pairs.

  9. Mobile, Collaborative Situated Knowledge Creation for Urban Planning

    Directory of Open Access Journals (Sweden)

    Nelson Baloian

    2012-05-01

    Full Text Available Geo-collaboration is an emerging research area in computer sciences studying the way spatial, geographically referenced information and communication technologies can support collaborative activities. Scenarios in which information associated to its physical location are of paramount importance are often referred as Situated Knowledge Creation scenarios. To date there are few computer systems supporting knowledge creation that explicitly incorporate physical context as part of the knowledge being managed in mobile face-to-face scenarios. This work presents a collaborative software application supporting visually-geo-referenced knowledge creation in mobile working scenarios while the users are interacting face-to-face. The system allows to manage data information associated to specific physical locations for knowledge creation processes in the field, such as urban planning, identifying specific physical locations, territorial management, etc.; using Tablet-PCs and GPS in order to geo-reference data and information. It presents a model for developing mobile applications supporting situated knowledge creation in the field, introducing the requirements for such an application and the functionalities it should have in order to fulfill them. The paper also presents the results of utility and usability evaluations.

  10. Mobile, collaborative situated knowledge creation for urban planning.

    Science.gov (United States)

    Zurita, Gustavo; Baloian, Nelson

    2012-01-01

    Geo-collaboration is an emerging research area in computer sciences studying the way spatial, geographically referenced information and communication technologies can support collaborative activities. Scenarios in which information associated to its physical location are of paramount importance are often referred as Situated Knowledge Creation scenarios. To date there are few computer systems supporting knowledge creation that explicitly incorporate physical context as part of the knowledge being managed in mobile face-to-face scenarios. This work presents a collaborative software application supporting visually-geo-referenced knowledge creation in mobile working scenarios while the users are interacting face-to-face. The system allows to manage data information associated to specific physical locations for knowledge creation processes in the field, such as urban planning, identifying specific physical locations, territorial management, etc.; using Tablet-PCs and GPS in order to geo-reference data and information. It presents a model for developing mobile applications supporting situated knowledge creation in the field, introducing the requirements for such an application and the functionalities it should have in order to fulfill them. The paper also presents the results of utility and usability evaluations.

  11. Contextual-Based Knowledge Creation for Agroindustrial Innovation

    Directory of Open Access Journals (Sweden)

    Elisa Anggraeni

    2017-08-01

    Full Text Available This paper discusses the knowledge creation process in one department, in a higher educational context, and the possible actions to take to improve the efficiency and effectiveness of the knowledge creation system in it. We conducted a case study at one department of a university that strives to improve its innovations, in terms of their quantity and quality.We used a soft system methodology to investigate the knowledge creation system in the chosen department. From the study, we conclude that the department can be considered as a learning organization, within which its staff continually create, acquire and transfer knowledge. This department has a learning environment which is conducive, concrete learning processes, and leadership that reinforces learning. In the context of producing agroindustry innovations, the knowledge creation system in this department is considered to be less effective since it frequently happens more at individual or small group levels. To improve its effectiveness, the management may facilitate the institutionalization of knowledge creation processes at every phase of the interactions between tacit and explicit knowledge.

  12. Polishing the craft of genetic diversity creation in directed evolution.

    Science.gov (United States)

    Tee, Kang Lan; Wong, Tuck Seng

    2013-12-01

    Genetic diversity creation is a core technology in directed evolution where a high quality mutant library is crucial to its success. Owing to its importance, the technology in genetic diversity creation has seen rapid development over the years and its application has diversified into other fields of scientific research. The advances in molecular cloning and mutagenesis since 2008 were reviewed. Specifically, new cloning techniques were classified based on their principles of complementary overhangs, homologous sequences, overlapping PCR and megaprimers and the advantages, drawbacks and performances of these methods were highlighted. New mutagenesis methods developed for random mutagenesis, focused mutagenesis and DNA recombination were surveyed. The technical requirements of these methods and the mutational spectra were compared and discussed with references to commonly used techniques. The trends of mutant library preparation were summarised. Challenges in genetic diversity creation were discussed with emphases on creating "smart" libraries, controlling the mutagenesis spectrum and specific challenges in each group of mutagenesis methods. An outline of the wider applications of genetic diversity creation includes genome engineering, viral evolution, metagenomics and a study of protein functions. The review ends with an outlook for genetic diversity creation and the prospective developments that can have future impact in this field. © 2013. Published by Elsevier Inc. All rights reserved.

  13. Organizational Knowledge Conversion and Creation Processes in a Chaotic Environment

    Directory of Open Access Journals (Sweden)

    Andrei Ștefan NESTIAN

    2013-05-01

    Full Text Available This is an explorative and conceptual paper, based on the analysis and comparison of relevant literature. the purpose of the article is to clarify the differences between knowledge creating processes and knowledge conversion processes, by analysing them when confronted with a chaotic environment. the way the knowledge conversion and creation processes are presented by Ikujiro Nonaka and his co-workers suggests the necessary existence of a Ba in order to generate the spiral of knowledge creation. this implies the acceptance of a relationship between the environment and the knowledge conversion process, in which the environment influences the knowledge creation. the article is based on the hypothesis that a chaotic environment, characterized by unpredictability, non-linearity and crisis, will lead to specific ways of functioning of the knowledge creation and conversion process that highlight the relations between the two different types of processes. Starting from the general concept of resilience, herein one proposes and explains the concept of resilience of the knowledge conversion system. the role of the attractors from the chaotic environment in the creation of new knowledge is identified and explained

  14. The Value Creation Logic and the Internationalisation of Internet Firms

    DEFF Research Database (Denmark)

    Blagoeva, Denitsa Hazarbassanova

    2016-01-01

    Purpose: The purpose of the research is to put to a test the belief that the idiosyncratic internationalisation process of Internet firms is homogeneous. The research question is thus, “How does the value creation logic of Internet firms influence their internationalisation process?”. Design....../methodology/approach: The authors answer this question using three cases illustrating the internationalisation process of three pure play digital service firms, each falling into one value creation logic. Findings: Each case company had a different approach to internationalisation, explained by a different theory. The firms...... differed in what their motivation was to internationalise, how they dealt with their liability of foreignness and how they learnt to internationalise. The differences were consistent with the specificities of their value creation. The contribution of this paper is to take the first steps towards linking...

  15. The Concept of Embodied Knowledge for Understanding Organisational Knowledge Creation

    Science.gov (United States)

    Matsudaira, Yoshito; Fujinami, Tsutomu

    Our goal in this paper is to understand, in the light of intuition and emotion, the problem-finding and value judgments by organisational members that are part of organisational knowledge creation. In doing so, we emphasise the importance of embodied knowledge of organisations as an explanatory concept. We propose ways of approaching intuition and sense of value as these are posited as objects of research. Approaches from the first, second, and third-person viewpoints result in a deeper grasp of embodied knowledge of organisations. Important in organisational knowledge creation is embodied knowledge of organisations, which has a bearing on problem-finding before any problem-solving or decision making takes place, and on value judgments about the importance of problems that have been found. This article proposes the concept of embodied knowledge, and, by introducing it, gives a profound understanding of that facet of organisational knowledge creation characterised by tacit knowledge held by organisational individuals.

  16. The Contribution of Intellectual Capital to Value Creation

    Directory of Open Access Journals (Sweden)

    Elena Shakina

    2013-12-01

    Full Text Available This paper studies the marginal contribution of intellectual capital (IC components to company value using a hedonic pricing framework. The ANOVA is used to identify group differences among different national markets and industries. Two models have been developed to reflect the time effect: one related to the immediate creation of value and another for the long term. As could be expected, the contribution of IC to companies’ value creation differs significantly between countries and industries. Both models, short- and long-term, are significant and with a normal explanatory power. We have found both positive and negative coefficients. Human capital plays a critical positive role in value creation in the short term. Structural and relational capital becomes more relevant in the long term. However, in the long term, the results obtained regarding the effect of human capital are unclear.

  17. Space Creation Mechanism during the Expansion of Universe

    Directory of Open Access Journals (Sweden)

    Emre Dil

    2016-01-01

    Full Text Available We propose a novel mechanism related to the expansion of universe. Recently Verlinde’s proposal has been applied to the deformed bosons being a candidate for the dark energy constituents, since the negative pressure of the deformed bosons. The expansion of universe is dependent on the dark energy and implies a creation of space; we admit that the space creation mechanism is related to the deformed bosons and so is the dark energy. In order to relate the dark energy and the mechanism for creation of space, we consider Verlinde’s proposal including the Holographic principle for emergence of space, which was recently applied to the deformed bosons. To check the validity of our mechanism, we calculate the ratio of the size of universe before and after the expansion and compare the results with the observational data. We find that the results are consistent with each other and infer that the proposed mechanism works correctly.

  18. Useful Business Cases: Value Creation in IS Projects

    DEFF Research Database (Denmark)

    Nielsen, Peter Axel; Persson, John Stouby

    2017-01-01

    Business cases have become popular as part of managing value creation in IS projects. Nevertheless, business cases are often poorly linked to value creation activities and organizations struggle to develop business cases that are useful and express more than simple cost savings. This action...... research study seeks to improve the usefulness of business cases in IS projects. We used collaborative action research with Danish municipalities to improve their practices when developing and using business cases and to change their perceptions of what constitutes a good business case that is useful...... during implementation and value creation. This article presents lessons learned from our action research, lessons that we incorporated into a business case method and subsequently evaluated with IS managers. There are three lessons on: (1) improving the content of business cases, (2) how to develop...

  19. Value Creation Logics and Internationalization of Service Firms

    DEFF Research Database (Denmark)

    Ørberg Jensen, Peter D.; Petersen, Bent

    2014-01-01

    on a thorough understanding of the fundamental nature of these firms. We put forward ten propositions concerning the pace of internationalization in service firms and the dominant foreign operation modes. The use of value creation logics can be a useful complement to the conventional approaches to the study....... The thrust of this study is that value creation logics, a construct originally developed by Stabell and Fjeldstad (1998) can assist us in better understanding why and how service firms internationalize. We extend this construct and propose that the internationalization of service firms must be based...... of service firms’ internationalization. However, the fact that most firms encompass more than one value creation logic complicates the use of firm databases and industry statistics. The study presents a novel theoretical approach and a set of propositions on service firm internationalization founded...

  20. Trinucleotide's quadruplet symmetries and natural symmetry law of DNA creation ensuing Chargaff's second parity rule.

    Science.gov (United States)

    Rosandić, Marija; Vlahović, Ines; Glunčić, Matko; Paar, Vladimir

    2016-07-01

    For almost 50 years the conclusive explanation of Chargaff's second parity rule (CSPR), the equality of frequencies of nucleotides A=T and C=G or the equality of direct and reverse complement trinucleotides in the same DNA strand, has not been determined yet. Here, we relate CSPR to the interstrand mirror symmetry in 20 symbolic quadruplets of trinucleotides (direct, reverse complement, complement, and reverse) mapped to double-stranded genome. The symmetries of Q-box corresponding to quadruplets can be obtained as a consequence of Watson-Crick base pairing and CSPR together. Alternatively, assuming Natural symmetry law for DNA creation that each trinucleotide in one strand of DNA must simultaneously appear also in the opposite strand automatically leads to Q-box direct-reverse mirror symmetry which in conjunction with Watson-Crick base pairing generates CSPR. We demonstrate quadruplet's symmetries in chromosomes of wide range of organisms, from Escherichia coli to Neanderthal and human genomes, introducing novel quadruplet-frequency histograms and 3D-diagrams with combined interstrand frequencies. These "landscapes" are mutually similar in all mammals, including extinct Neanderthals, and somewhat different in most of older species. In human chromosomes 1-12, and X, Y the "landscapes" are almost identical and slightly different in the remaining smaller and telocentric chromosomes. Quadruplet frequencies could provide a new robust tool for characterization and classification of genomes and their evolutionary trajectories.

  1. Space-Efficient Re-Pair Compression

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Prezza, Nicola

    2017-01-01

    Re-Pair [5] is an effective grammar-based compression scheme achieving strong compression rates in practice. Let n, σ, and d be the text length, alphabet size, and dictionary size of the final grammar, respectively. In their original paper, the authors show how to compute the Re-Pair grammar...

  2. Exploring Pair Programming Benefits for MIS Majors

    Science.gov (United States)

    Dongo, Tendai; Reed, April H.; O'Hara, Margaret

    2016-01-01

    Pair programming is a collaborative programming practice that places participants in dyads, working in tandem at one computer to complete programming assignments. Pair programming studies with Computer Science (CS) and Software Engineering (SE) majors have identified benefits such as technical productivity, program/design quality, academic…

  3. Enzymatic incorporation of a third nucleobase pair

    National Research Council Canada - National Science Library

    Yang, Zunyi; Sismour, A. Michael; Sheng, Pinpin; Puskar, Nyssa L; Benner, Steven A

    2007-01-01

    DNA polymerases are identified that copy a non-standard nucleotide pair joined by a hydrogen bonding pattern different from the patterns joining the dA:T and dG:dC pairs. 6-Amino-5-nitro-3-(1′-β-d-2′-deoxyribofuranosyl)-2(1H)-pyridone (dZ...

  4. Drift wave in pair-ion plasma

    Indian Academy of Sciences (India)

    ion plasma are discussed. It is shown that the temperature and/or mass difference of both species could produce drift wave in a pair-ion plasma. The results are discussed in the context of the fullerene pair-ion plasma experiment.

  5. How to Analyze Paired Comparison Data

    Science.gov (United States)

    2011-05-01

    How to Analyze Paired Comparison Data Kristi Tsukida and Maya R. Gupta Department of Electrical Engineering University of Washington Seattle, WA...REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE How to Analyze Paired Comparison Data 5a. CONTRACT NUMBER 5b. GRANT

  6. Electron pairing in nonlinear nanoelectromechanical systems

    Science.gov (United States)

    Droth, Matthias; Szechenyi, Gabor; Palyi, Andras

    Despite the success of BCS-theory, the underlying mechanism for electron-pairing remains elusive for many superconducting materials. For SrTiO3, it has been shown that electron-pairing outside the superconducting regime can be explained with an effectively negative charging energy U graphene resonator.

  7. Drift wave in pair-ion plasma

    Indian Academy of Sciences (India)

    Xz; 52.27.Cm; 52.35.Kt. 1. Introduction. There has been an accrued interest in pair-ion plasmas, motivated by a recent experiment. [1] on particles with equal charge-to-mass ratio. Pair plasmas are also found in astro- physical environments [2].

  8. Kinetic energy driven pairing in cuprate superconductors

    NARCIS (Netherlands)

    Maier, TA; Jarrell, M; Macridin, A; Slezak, C

    2004-01-01

    Pairing occurs in conventional superconductors through a reduction of the electronic potential energy accompanied by an increase in kinetic energy. In the underdoped cuprates, optical experiments show that pairing is driven by a reduction of the electronic kinetic energy. Using the dynamical cluster

  9. The cost of wetland creation and restoration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    King, D.; Bohlen, C.

    1995-08-01

    This report examines the economics of wetland creation, restoration, and enhancement projects, especially as they are used within the context of mitigation for unavoidable wetland losses. Complete engineering-cost-accounting profiles of over 90 wetland projects were developed in collaboration with leading wetland restoration and creation practitioners around the country to develop a primary source database. Data on the costs of over 1,000 wetland projects were gathered from published sources and other available databases to develop a secondary source database. Cases in both databases were carefully analyzed and a set of baseline cost per acre estimates were developed for wetland creation, restoration, and enhancement. Observations of costs varied widely, ranging from $5 per acre to $1.5 million per acre. Differences in cost were related to the target wetland type, and to site-specific and project-specific factors that affected the preconstruction, construction, and post-construction tasks necessary to carry out each particular project. Project-specific and site-specific factors had a much larger effect on project costs than wetland type for non-agricultural projects. Costs of wetland creation and restoration were also shown to differ by region, but not by as much as expected, and in response to the regulatory context. The costs of wetland creation, restoration, and enhancement were also analyzed in a broader economic context through examination of the market for wetland mitigation services, and through the development of a framework for estimating compensation ratios-the number of acres of created, restored, or enhanced wetland required to compensate for an acre of lost natural wetland. The combination of per acre creation, restoration, and enhancement costs and the compensation ratio determine the overall mitigation costs associated with alternative mitigation strategies.

  10. The incoming trends of end-user driven service creation

    OpenAIRE

    Zhao, Zhenzhen; Laga, Nassim; Crespi, Noel

    2010-01-01

    Service creation is the next big end-user driven hype in the technology arena. As the first Web 2.0 services are already enabling tech-inclined users to build their own composite services, this trend will lead to a huge set of new features and services will be provided by all stakeholders. This paper illustrates the incoming trends of the end-user driven service creation with extensive new features, and provides five main research topics from both technical and business perspective. The under...

  11. A Critical Analysis of the Knowledge Creation Process

    Directory of Open Access Journals (Sweden)

    Stephen Probert

    2003-11-01

    Full Text Available The topic of knowledge creation (Nonaka and Takeuchi, 1995 will be analysed from a philosophical perspective. To begin with, the key motivations behind the discourse of knowledge creation and management are briefly discussed. The contemporary distinction between tacit and explicit knowledge is then explored. Following this, the work of Lyotard on knowledge in a (postmodern economy will be summarised. The paper then explores how some of the work by Foucault and Adorno may provide a new direction for developing research approaches in this area.

  12. Particle creation and reheating in a braneworld inflationary scenario

    Science.gov (United States)

    Bilić, Neven; Domazet, Silvije; Djordjevic, Goran S.

    2017-10-01

    We study the cosmological particle creation in the tachyon inflation based on the D-brane dynamics in the Randall-Sundrum (RSII) model extended to include matter in the bulk. The presence of matter modifies the warp factor which results in two effects: a modification of the RSII cosmology and a modification of the tachyon potential. Besides, a string theory D-brane supports among other fields a U(1) gauge field reflecting open strings attached to the brane. We demonstrate how the interaction of the tachyon with the U(1) gauge field drives cosmological creation of massless particles and estimate the resulting reheating at the end of inflation.

  13. Value Encounters - Modeling and Analyzing Co-creation of Value

    Science.gov (United States)

    Weigand, Hans

    Recent marketing and management literature has introduced the concept of co-creation of value. Current value modeling approaches such as e3-value focus on the exchange of value rather than co-creation. In this paper, an extension to e3-value is proposed in the form of a “value encounter”. Value encounters are defined as interaction spaces where a group of actors meet and derive value by each one bringing in some of its own resources. They can be analyzed from multiple strategic perspectives, including knowledge management, social network management and operational management. Value encounter modeling can be instrumental in the context of service analysis and design.

  14. What does existing research say about value co-creation?

    DEFF Research Database (Denmark)

    Thomsen, Merethe Stjerne; Tanev, Stoyan; Pedrosa, Alex

    2010-01-01

    of four emerging subject areas within marketing science, service management, new product development & innovation and general business and management. The four subject areas lead to new key driving forces of value co-creation by involving the customers in experience networks, where both creating...... and sustaining a rewarding virtual customer environment should not be underestimated. Co-creation is also a key component within service management, where a product is mainly an enabler of a service, and it influences the general field of product development and innovation. Customers are engaged through company...

  15. Exploring Knowledge Creation Processes as a Source of Organizational Learning

    DEFF Research Database (Denmark)

    Brix, Jacob

    2017-01-01

    The purpose of the study is to reestablish the link between theories of organizational learning and knowledge creation – theories that in research, have been pursued as independent themes for almost two decades. Based on the literature review, I build a framework that proposes how the two streams...... build eight propositions that are used to discuss and extend the organizational learning and knowledge creation literatures and to justify the framework’s applicability. Finally, I present the managerial implications and the conclusions of the study....

  16. Job creation and destruction, worker reallocation and wages

    DEFF Research Database (Denmark)

    Belzil, Christian

    1997-01-01

    Using Danish firm level data on employment dynamics merged with individual records on all workers in a given firm, various measures of employment and worker reallocation used in the macroeconomics literature are incorporated in a wage equation framework. The effects of job creation/destruction an......Using Danish firm level data on employment dynamics merged with individual records on all workers in a given firm, various measures of employment and worker reallocation used in the macroeconomics literature are incorporated in a wage equation framework. The effects of job creation....../destruction and worker rellocation are estimated using standard panel data techniques. Brief results will go here!!!...

  17. Designer Modeling for Personalized Game Content Creation Tools

    DEFF Research Database (Denmark)

    Liapis, Antonios; Yannakakis, Georgios N.; Togelius, Julian

    2013-01-01

    With the growing use of automated content creation and computer-aided design tools in game development, there is potential for enhancing the design process through personalized interactions between the software and the game developer. This paper proposes designer modeling for capturing the designer......’s preferences, goals and processes from their interaction with a computer-aided design tool, and suggests methods and domains within game development where such a model can be applied. We describe how designer modeling could be integrated with current work on automated and mixed-initiative content creation......, and envision future directions which focus on personalizing the processes to a designer’s particular wishes....

  18. Nonlinear phenomenon in nanostructures creation by fast cluster ions

    Science.gov (United States)

    Moslem, W. M.; El-Said, A. S.; Sabry, R.; Shalouf, A.; El-Labany, S. K.; Bahlouli, H.

    2017-01-01

    The development of accelerators technology offers a new window for the creation of surface nanostructures in an efficient and accurate way. The use of 30 MeV C60 cluster ions enables the creation of nano-hillocks of size larger than the ones produced by GeV monoatomic ions. The physical mechanism underlying the realization of such nanostructures is elucidated using a plasma expansion approach. Numerical analysis showed that increasing the ionic temperature (number density) ratios would lead to decrease (increase) the nano-hillocks height.

  19. Successful femtosecond LASIK flap creation despite multiple suction losses

    Science.gov (United States)

    Syed, Zeba A.; Melki, Samir A.

    2014-01-01

    Summary We present a case of successful completion of a laser in situ keratomileusis (LASIK) procedure despite 5 episodes of suction loss during femtosecond flap creation in a 30-year-old man with no risk factors. The patient had an uncorrected distance visual acuity of 20/20 in both eyes at his 2-month follow-up visit. Our experience in this case shows that multiple suction losses during femtosecond LASIK flap creation do not preclude completion of a successful procedure with excellent visual outcomes. Caution and technique modification are advised if multiple laser passes are applied to avoid creating multiplanar flaps. PMID:25097457

  20. The information contained in multiple sibling pairs.

    Science.gov (United States)

    Hodge, S E

    1984-01-01

    In a sibship of size s, s(s-1)/2 sib pairs can be formed, but these pairs are statistically dependent when s greater than 2. This study examines how much independent information is obtained when all possible pairs are used to evaluate the sharing of genes identical by descent. A logarithmic measure of information, sigma pilog2pi [Shannon, 1948], is used. The basic unit of information is the binomial "bit," or the amount of information in the toss of a fair coin. It is shown that a single independent sib pair contains 1.5 bits. The complete sibship contains a total of 2s-3+(1/2)s-1 bits, or (2s-3+(1/2)s-1)/1.5 pair-equivalents of information. The information is reduced if all sib genotypes do not occur with equal probability.

  1. The relationship between the beliefs of school board members concerning Young Earth Creationism and Old Earth Creationism and the inclusion of creationism in the science curriculum of Georgia public schools

    Science.gov (United States)

    Cook, Karen S.

    This study investigated district location and the beliefs of school board members regarding Young Earth Creationism (YEC) and Old Earth Creationism (OEC) associated with the inclusion or exclusion of creationism in the district science curriculum of Georgia public schools. A random sampling of 144 mailed of a total population of 1,034 local school board members was selected as subjects. Data analysis indicated that beliefs of school board members in Young Earth Creationism had a weak, positive association with the permitted inclusion of creationism in the district science curriculum while board member beliefs in OEC had a moderate, negative relationship. No association was found between board member beliefs in either Young Earth Creationism or Old Earth Creationism and the required inclusion of creationism in district creationism in Georgia public schools. Concerning district location (rural, urban, or suburban) and the permitted or mandatory inclusion of creationism, no relationship was found. The results of this study provide insight into connections between beliefs of board members and the inclusion of creationism, which may translate into enlightened voting decisions.

  2. Weird Stellar Pair Puzzles Scientists

    Science.gov (United States)

    2008-05-01

    Astronomers have discovered a speedy spinning pulsar in an elongated orbit around an apparent Sun-like star, a combination never seen before, and one that has them puzzled about how the strange system developed. Orbital Comparison Comparing Orbits of Pulsar and Its Companion to our Solar System. CREDIT: Bill Saxton, NRAO/AUI/NSF Click on image for full caption information and available graphics. "Our ideas about how the fastest-spinning pulsars are produced do not predict either the kind of orbit or the type of companion star this one has," said David Champion of the Australia Telescope National Facility. "We have to come up with some new scenarios to explain this weird pair," he added. Astronomers first detected the pulsar, called J1903+0327, as part of a long-term survey using the National Science Foundation's Arecibo radio telescope in Puerto Rico. They made the discovery in 2006 doing data analysis at McGill University, where Champion worked at the time. They followed up the discovery with detailed studies using the Arecibo telescope, the NSF's Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, the Westerbork radio telescope in the Netherlands, and the Gemini North optical telescope in Hawaii. The pulsar, a city-sized superdense stellar corpse left over after a massive star exploded as a supernova, is spinning on its axis 465 times every second. Nearly 21,000 light-years from Earth, it is in a highly-elongated orbit that takes it around its companion star once every 95 days. An infrared image made with the Gemini North telescope in Hawaii shows a Sun-like star at the pulsar's position. If this is an orbital companion to the pulsar, it is unlike any companions of other rapidly rotating pulsars. The pulsar, a neutron star, also is unusually massive for its type. "This combination of properties is unprecedented. Not only does it require us to figure out how this system was produced, but the large mass may help us understand how matter behaves at extremely

  3. A Curious Pair of Galaxies

    Science.gov (United States)

    2009-03-01

    The ESO Very Large Telescope has taken the best image ever of a strange and chaotic duo of interwoven galaxies. The images also contain some surprises -- interlopers both far and near. ESO PR Photo 11a/09 A Curious Pair of Galaxies ESO PR Video 11a/09 Arp 261 zoom in ESO PR Video 11b/09 Pan over Arp 261 Sometimes objects in the sky that appear strange, or different from normal, have a story to tell and prove scientifically very rewarding. This was the idea behind Halton Arp's catalogue of Peculiar Galaxies that appeared in the 1960s. One of the oddballs listed there is Arp 261, which has now been imaged in more detail than ever before using the FORS2 instrument on ESO's Very Large Telescope. The image proves to contain several surprises. Arp 261 lies about 70 million light-years distant in the constellation of Libra, the Scales. Its chaotic and very unusual structure is created by the interaction of two galaxies that are engaged in a slow motion, but highly disruptive close encounter. Although individual stars are very unlikely to collide in such an event, the huge clouds of gas and dust certainly do crash into each other at high speed, leading to the formation of bright new clusters of very hot stars that are clearly seen in the picture. The paths of the existing stars in the galaxies are also dramatically disrupted, creating the faint swirls extending to the upper left and lower right of the image. Both interacting galaxies were probably dwarfs not unlike the Magellanic Clouds orbiting our own galaxy. The images used to create this picture were not actually taken to study the interacting galaxies at all, but to investigate the properties of the inconspicuous object just to the right of the brightest part of Arp 261 and close to the centre of the image. This is an unusual exploding star, called SN 1995N, that is thought to be the result of the final collapse of a massive star at the end of its life, a so-called core collapse supernova. SN 1995N is unusual because

  4. Solar test of Dirac's large number hypothesis. [multiplicative creation model for solar evolution

    Science.gov (United States)

    Chin, C.-W.; Stothers, R.

    1975-01-01

    An investigation is conducted regarding the implications of Dirac's theories (1973, 1974) concerning the creation of new matter. It is found that Dirac's theory of multiplicative creation, but not his theory of additive creation, is not in contradiction with known facts about the sun. According to the theory of additive creation, matter is formed uniformly throughout space. The concept of multiplicative creation implies that existing matter multiplies itself in proportion to the amount of matter already present.

  5. String pair production in non homogeneous backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Bolognesi, S. [Department of Physics “E. Fermi” University of Pisa, and INFN - Sezione di Pisa,Largo Pontecorvo, 3, Ed. C, 56127 Pisa (Italy); Rabinovici, E. [Racah Institute of Physics, The Hebrew University of Jerusalem,91904 Jerusalem (Israel); Tallarita, G. [Departamento de Ciencias, Facultad de Artes Liberales,Universidad Adolfo Ibáñez, Santiago 7941169 (Chile)

    2016-04-28

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is less suppressed than the rate of particle pair production. We discuss in some detail how the critical field is affected by the non-homogeneity, for both time and space dependent electric field backgrouds. We also comment on what could be an interesting new prediction for the small field limit. The third case we consider is pair production in holographic confining backgrounds with homogeneous and non-homogeneous fields.

  6. Exploring Pair Programming Benefits for MIS Majors

    Directory of Open Access Journals (Sweden)

    April H. Reed

    2016-12-01

    Full Text Available Pair programming is a collaborative programming practice that places participants in dyads, working in tandem at one computer to complete programming assignments. Pair programming studies with Computer Science (CS and Software Engineering (SE majors have identified benefits such as technical productivity, program/design quality, academic performance, and increased satisfaction for their participants. In this paper, pair programming is studied with Management Information Systems (MIS majors, who (unlike CS and SE majors taking several programming courses typically take only one programming course and often struggle to develop advanced programming skills within that single course. The researchers conducted two pair programming experiments in an introductory software development course for MIS majors over three semesters to determine if pair programming could enhance learning for MIS students. The program results, researchers’ direct observations, and participants’ responses to a survey questionnaire were analyzed after each experiment. The results indicate that pair programming appears to be beneficial to MIS students’ technical productivity and program design quality, specifically the ability to create programs using high-level concepts. Additionally, results confirmed increased student satisfaction and reduced frustration, as the pairs worked collaboratively to produce a program while actively communicating and enjoying the process.

  7. Time-resolved statistics of photon pairs in two-cavity Josephson photonics

    Energy Technology Data Exchange (ETDEWEB)

    Dambach, Simon; Kubala, Bjoern; Ankerhold, Joachim [Institute for Complex Quantum Systems and IQST, Ulm University (Germany)

    2017-06-15

    We analyze the creation and emission of pairs of highly nonclassical microwave photons in a setup where a voltage-biased Josephson junction is connected in series to two electromagnetic oscillators. Tuning the external voltage such that the Josephson frequency equals the sum of the two mode frequencies, each tunneling Cooper pair creates one additional photon in both of the two oscillators. The time-resolved statistics of photon emission events from the two oscillators is investigated by means of single- and cross-oscillator variants of the second-order correlation function g{sup (2)}(τ) and the waiting-time distribution w(τ). They provide insight into the strongly correlated quantum dynamics of the two oscillator subsystems and reveal a rich variety of quantum features of light including strong antibunching and the presence of negative values in the Wigner function. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Gamma beams generation with high intensity lasers for two photon Breit-Wheeler pair production

    Science.gov (United States)

    D'Humieres, Emmanuel; Ribeyre, Xavier; Jansen, Oliver; Esnault, Leo; Jequier, Sophie; Dubois, Jean-Luc; Hulin, Sebastien; Tikhonchuk, Vladimir; Arefiev, Alex; Toncian, Toma; Sentoku, Yasuhiko

    2017-10-01

    Linear Breit-Wheeler pair creation is the lowest threshold process in photon-photon interaction, controlling the energy release in Gamma Ray Bursts and Active Galactic Nuclei, but it has never been directly observed in the laboratory. Using numerical simulations, we demonstrate the possibility to produce collimated gamma beams with high energy conversion efficiency using high intensity lasers and innovative targets. When two of these beams collide at particular angles, our analytical calculations demonstrate a beaming effect easing the detection of the pairs in the laboratory. This effect has been confirmed in photon collision simulations using a recently developed innovative algorithm. An alternative scheme using Bremsstrahlung radiation produced by next generation high repetition rate laser systems is also being explored and the results of first optimization campaigns in this regime will be presented.

  9. Levitation Performance of Two Opposed Permanent Magnet Pole-Pair Separated Conical Bearingless Motors

    Science.gov (United States)

    Kascak, Peter; Jansen, Ralph; Dever, Timothy; Nagorny, Aleksandr; Loparo, Kenneth

    2013-01-01

    In standard motor applications, rotor suspension with traditional mechanical bearings represents the most economical solution. However, in certain high performance applications, rotor suspension without contacting bearings is either required or highly beneficial. Examples include applications requiring very high speed or extreme environment operation, or with limited access for maintenance. This paper expands upon a novel bearingless motor concept, in which two motors with opposing conical air-gaps are used to achieve full five-axis levitation and rotation of the rotor. Force in this motor is created by deliberately leaving the motor s pole-pairs unconnected, which allows the creation of different d-axis flux in each pole pair. This flux imbalance is used to create lateral force. This approach is different than previous bearingless motor designs, which require separate windings for levitation and rotation. This paper examines the predicted and achieved suspension performance of a fully levitated prototype bearingless system.

  10. Geometrical ambiguity of pair statistics: point configurations.

    Science.gov (United States)

    Jiao, Y; Stillinger, F H; Torquato, S

    2010-01-01

    Point configurations have been widely used as model systems in condensed-matter physics, materials science, and biology. Statistical descriptors, such as the n -body distribution function g(n), are usually employed to characterize point configurations, among which the most extensively used is the pair distribution function g(2). An intriguing inverse problem of practical importance that has been receiving considerable attention is the degree to which a point configuration can be reconstructed from the pair distribution function of a target configuration. Although it is known that the pair-distance information contained in g(2) is, in general, insufficient to uniquely determine a point configuration, this concept does not seem to be widely appreciated and general claims of uniqueness of the reconstructions using pair information have been made based on numerical studies. In this paper, we present the idea of the distance space called the D space. The pair distances of a specific point configuration are then represented by a single point in the D space. We derive the conditions on the pair distances that can be associated with a point configuration, which are equivalent to the realizability conditions of the pair distribution function g(2). Moreover, we derive the conditions on the pair distances that can be assembled into distinct configurations, i.e., with structural degeneracy. These conditions define a bounded region in the D space. By explicitly constructing a variety of degenerate point configurations using the D space, we show that pair information is indeed insufficient to uniquely determine the configuration in general. We also discuss several important problems in statistical physics based on the D space, including the reconstruction of atomic structures from experimentally obtained g(2) and a recently proposed "decorrelation" principle. The degenerate configurations have relevance to open questions involving the famous traveling salesman problem.

  11. The Dollar Game Curriculum: Inspiring Wealth Creation in Rural Communities

    Science.gov (United States)

    Braak, Willem J.; Lewin, Paul A.

    2015-01-01

    Rural wealth creation and local entrepreneurship are emerging economic development approaches that bring back a sense of self-determination to rural communities. However, their potential is often greatly diminished by preconceived and opposing notions within the community on what drives economic growth. The Dollar Game is an innovative curriculum…

  12. The Spirit of Adventure and the Art of Creation

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 7. The Spirit of Adventure and the Art of Creation: Camphor to Vitamin B12. Setty Mallikarjuna Babu Subramania Ranganathan. General Article Volume 19 Issue 7 July 2014 pp 593-623 ...

  13. Applying the knowledge creation model to the management of ...

    African Journals Online (AJOL)

    In present-day society, the need to manage indigenous knowledge is widely recognised. However, there is a debate in progress on whether or not indigenous knowledge can be easily managed. The purpose of this paper is to examine the possibility of using knowledge management models like knowledge creation theory ...

  14. The Spirit of Adventure and the Art of Creation

    Indian Academy of Sciences (India)

    IAS Admin

    twain meet that creativity is manifested. Arthur Koestler, in his book The Act of Creation, has discussed several instances where such impacting of two different matrices of thought has led to novelty and creativity. One can describe Woodward's art in organic synthesis in the same words – his naming the challenge,.

  15. Venture Creation Programs: Bridging Entrepreneurship Education and Technology Transfer

    Science.gov (United States)

    Lackéus, Martin; Williams Middleton, Karen

    2015-01-01

    Purpose: The purpose of this paper is to explore how university-based entrepreneurship programs, incorporating real-life venture creation into educational design and delivery, can bridge the gap between entrepreneurship education and technology transfer within the university environment. Design/methodology/approach: Based on a literature review…

  16. Magnetized jet creation using a ring laser and applications

    Science.gov (United States)

    Liang, Edison; Gao, Ian; Lu, Yingchao; Ji, Hantao; Follett, Russ; Froula, Dustin; Tzeferacos, Petros; Lamb, Donald; Bickel, Andrew; Sio, Hong; Li, Chi Kiang; Petrasso, Richard; Wei, Mingsheng; Fu, Wen; Han, Lily

    2017-10-01

    We have recently demonstrated a new robust platform of magnetized jet creation using 20 OMEGA beams to form a hollow ring. We will present the latest experimental results and their theoretical interpretation, and explore potential applications to laboratory astrophysics, fundamental plasma physics and other areas. We will also discuss the scaling of this platform to future NIF experiments.

  17. The Challenges of Collaborative Knowledge Creation in Open Innovation Teams

    NARCIS (Netherlands)

    Chatenier, du E.; Verstegen, J.A.A.M.; Biemans, H.; Mulder, M.; Omta, S.W.F.

    2009-01-01

    In open innovation teams, people from different organizations work together to develop new products, services, or markets. This organizational diversity can positively influence collaborative knowledge creation but can frustrate and obstruct the process as well. To increase the success rates of open

  18. Heterogeneous motives and the collective creation of value

    NARCIS (Netherlands)

    Bridoux, F.; Coeurderoy, R.; Durand, R.

    2011-01-01

    The collective creation of value has remained underexplored in management research. Drawing on social psychology and behavioral economics, we analyze the impact of the mix of employee motives to cooperate and compare the collective value generated by three motivational systems: individual monetary

  19. The Politics of States', Local Governments' Creation and Nigeria's ...

    African Journals Online (AJOL)

    Nekky Umera

    linked to a programme of transition from military to civilian rule. Thus, the creation of new states was officially presented as a problematic and disruptive issue, which a 'corrective' military regime should resolve before handing-over power to civilian rulers. Unlike Gowon administration, which. The Politics of States and Local ...

  20. The Learning Conference: Knowledge Creation through Participation and Publication

    Science.gov (United States)

    Louw, Ina; Zuber-Skerritt, Ortrun

    2011-01-01

    Purpose: The aim of this paper is to identify the principles and characteristics of a learning conference which uses action learning and action research (ALAR) processes to create: optimal learning for all participants through a collaborative, inclusive conference culture; further knowledge creation in publishing conference papers post-conference…

  1. The Leader's Role in Strategic Knowledge Creation and Mobilization

    Science.gov (United States)

    Reid, Steven

    2013-01-01

    The purpose of this paper is to explore how leaders influence knowledge creation and mobilization processes. As a basis for the theoretical framework, the researcher selected theories that informed the investigation of this influence: leadership theory, knowledge theory, learning theory, organizational learning theory, and organizational knowledge…

  2. MODERN INDICATORS DERIVED FROM VALUE CREATION AND DISCOUNTED

    Directory of Open Access Journals (Sweden)

    Cican Simona

    2013-07-01

    In this article, we will present the connection between discounted cash flow methods and the indicators derived from value creation, based on the business finance theory, which says that firm value will increase if projects with positive net present value are accepted, while it will be destroyed if projects with negative net present value are accepted.

  3. Role of Waste Management in Wealth Creation in Nigeria ...

    African Journals Online (AJOL)

    The concept of entrepreneurship as it relates to waste to wealth by private sector participation (PSP) franchise is considered to have assisted the government create jobs and new businesses for many in contemporary economies, This study essentially try to access whether PSP franchise operators aid in the creation of jobs ...

  4. Creation and Validation of a Sabbatical Assessment Instrument.

    Science.gov (United States)

    Miller, Michael T.

    Personal narratives provide typically unabashed enthusiasm for sabbatical leave programs, but few studies have explored the results of sabbaticals and the impact that these sabbaticals can and do have on the department and the university. This paper reports on the creation of an assessment instrument to measure the impact of a faculty member's…

  5. Collaboration, Innovation, and Value Creation in a Global Telecom

    Science.gov (United States)

    Allee, Verna; Taug, Jan

    2006-01-01

    Purpose: The purpose of this paper is to review a systemic organizational change initiative for improving collaboration, innovation and value creation at a global telecom. Design/methodology/approach: Based on a comprehensive internal assessment Telenor identified core issues and challenges in supporting collaboration after several years of…

  6. The Framework of Knowledge Creation for Online Learning Environments

    Science.gov (United States)

    Huang, Hsiu­-Mei; Liaw, Shu­-Sheng

    2004-01-01

    In today's competitive global economy characterized by knowledge acquisition, the concept of knowledge management has become increasingly prevalent in academic and business practices. Knowledge creation is an important factor and remains a source of competitive advantage over knowledge management. Information technology facilitates knowledge…

  7. Information Technology: A challenge to the Creation and ...

    African Journals Online (AJOL)

    As organisations increasingly adopt the use of information and communication technologies, the corresponding increase in the creation of electronic records has brought about a number of records management challenges. These manifest themselves in a number of ways. Problems associated with the management of ...

  8. Tolkien's Creation Myth in "The Silmarillion"--Northern or Not?

    Science.gov (United States)

    Gough, John

    1999-01-01

    Notes that J.R.R. Tolkien's work is commonly supposed to be greatly influenced by Norse mythology and legend. Compares Tolkien's account of the creation of Middle Earth to the Norse myth of Yggdrasil. Concludes that Tolkien took qualities of language, a code of bravery and honor, and many incidental Norse details and absorbed them into a very…

  9. The theology of creation in Vito Mancuso's radical theology | Simut ...

    African Journals Online (AJOL)

    Thus, matter is the mother of all existing realities which include the universe, nature and even the soul. In other ... program includes the traditional doctrine of creation, which in Mancuso acquires a new facet as it is described in terms related to his conviction that the origin of everything should be understood in material terms.

  10. ORIGIN: metal creation and evolution from the cosmic dawn

    NARCIS (Netherlands)

    den Herder, J.W.A.; Piro, L.; Ohashi, T.; Kouveliotou, C.; Hartmann, D.H.; Kaastra, J.S.|info:eu-repo/dai/nl/070911134; Amati, L.

    2011-01-01

    ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions of all abundant elements between C and Ni to red-shifts of z = 10,

  11. Space Creation Dynamics in Basketball Small-Sided Games.

    Science.gov (United States)

    Bredt, Sarah G T; Morales, Juan C P; Andrade, André G P; Torres, Juliana O; Peixoto, Gustavo H; Greco, Pablo J; Praça, Gibson M; Chagas, Mauro H

    2017-01-01

    Space creation dynamics (SCDs) describe actions players perform to create a scoring opportunity. This study compared SCDs and types of offense during three different three versus three (3vs.3) basketball small-sided games (SSGs) played in half court: 3vs.3 with man-to-man defense in half playing area (3vs.3HALF), 3vs.3 with man-to-man defense in full playing area (3vs.3FULL), and 3vs.3 with reduced shot clock (3vs.3RT). We also investigated the efficacy of SCDs in all SSGs and the reliability of SCDs in 3vs.3HALF. While the efficacy of SCDs did not differ among these SSGs, 3vs.3RT presented significantly more "space creation with ball dribbled" and "shot clock violations," and less "on ball screens." 3vs.3FULL presented no differences in the SCDs and types of offense compared with 3vs.3HALF. Reliability within 3vs.3HALF was higher for "space creation with ball dribbled," "space creation without the ball," "set offenses," "fast breaks," and "loss of ball during passing or dribbling." We concluded that 3vs.3 basketball SSGs with different rules can be used for training different tactical behaviors important to formal games, especially since the 3vs.3HALF presented good reliability for many variables related to tactical behavior.

  12. Ambient air pollution and assessment of ozone creation potential for ...

    African Journals Online (AJOL)

    Volatile organic compound (VOC) species react at different rate and exhibit differences in reactivity with respect to ozone formation in polluted urban atmosphere. To assess this, the variations pattern, reactivity relative to OH radical and ozone creation potential of ambient VOCs were investigated in field studies at ...

  13. Chemical Education: A Tool for Wealth Creation from Waste ...

    African Journals Online (AJOL)

    This paper focuses on exposing the indispensible role of chemical education in wealth creation from waste. Every settlement of people has one type of waste or the other to dispose. The challenge of waste management has in recent time occupied researchers such that innovations are geared towards reducing wastes that ...

  14. Federalism, State Creation and the Minority Ethnic Groups in ...

    African Journals Online (AJOL)

    Federalism, State Creation and the Minority Ethnic Groups in Nigeria's National Integration Project. ... Journal Home > Vol 5, No 1 (2016) > ... Nigeria gained independence in 1960 as a tripartite regional federal system which promoted the hegemony of three major ethnic groups (the Yorubas in the west, the Ibos in the east ...

  15. Value creation of road infrastructure networks: a structural equation approach

    NARCIS (Netherlands)

    Hartmann, Andreas; Ling, F.Y.Y.

    2016-01-01

    Although road agencies need to provide road infrastructure that is beneficial for road users, little is known about how the activities of the agencies influence the value creation of road infrastructure. From a service-dominant logic perspective, the importance of road maintenance and traffic

  16. Applying the knowledge creation model to the management of ...

    African Journals Online (AJOL)

    user

    Social Cognitive Theory (SCT) (Bandura 1977), which examines the processes of cognitive experiences and values in the ..... Gourlay, S. 2006. Conceptualizing knowledge creation: A critique of Nonaka's theory. Journal of. Management Studies, 43(7), 1415-1436. Harsh, O. K. 2009. Three dimensional knowledge ...

  17. Value creation and knowledge development in tourism experience encounters

    DEFF Research Database (Denmark)

    Sørensen, Flemming; Jensen, Jens Friis

    2015-01-01

    encounters’ by integrating them into the tourism experience to which they are related, this will create added experiential value for tourists and increase the creation of knowledge about users. This is illustrated in an innovation field experiment in a retro design boutique hotel in which service encounters...

  18. International Business Models Developed Through Brokerage Knowledge and Value Creation

    DEFF Research Database (Denmark)

    Petersen, Nicolaj Hannesbo; Rasmussen, Erik Stavnsager

    This paper highlights theoretically and empirically international business model decisions in networks with knowledge sharing and value creation. The paper expands the conceptual in-ternational business model framework for technology-oriented companies to include the focal firm’s network role...

  19. NEW VENTURE CREATION: HOW START-UPS GROW?

    Directory of Open Access Journals (Sweden)

    AIDIN SALAMZADEH

    Full Text Available ABSTRACT Start-ups, often seen as sources of innovation and change, are prone to failure and accordingly they are attracting considerable attention not least from policy makers and Government officials. However, the various new venture creation studies that have emerged since the early 1980s lack cohesiveness, and the domain remains controversial. This article not only exposes the limitations of the existing body of understanding on the topic but attempts to develop a more comprehensive and comprehendible framework for start up (new venture creation. To do so it uses the frameworks proposed by Whetten, and March and Smith to develop 11 propositions. The resultant model suggests that the creation of a start up involves the identification of an idea or opportunity by an entrepreneur who subsequently organizes a series of activities, mobilizes resources and creates competence using his/her networks in an environment in order to create value. It sheds light on the start-up (new venture creation process and has relevance for entrepreneurs, policy makers and researchers.

  20. Stakeholder interactions to support service creation in cloud computing

    NARCIS (Netherlands)

    Wang, Lei; Ferreira Pires, Luis; Wombacher, Andreas; van Sinderen, Marten J.; Chi, Chihung

    2010-01-01

    Cloud computing is already a major trend in IT. Cloud services are being offered at application (software), platform and infrastructure levels. This paper presents our initial modeling efforts towards service creation at the infrastructure level. The purpose of these modeling efforts is to

  1. NATURE AND SCULPTURE IN THE CREATION OF AFRICAN ...

    African Journals Online (AJOL)

    The meaning of space is defined by the images contained in that space. Creating scenery for the theatre as an indoor activity involves either the creation of imaginary forms or the replication of existing images around the creator's environment. These imported items include natural vegetation, architecture, sculpture and ...

  2. Methods for increasing biodiversity in wetland creation and restoration efforts

    Science.gov (United States)

    Ross Coleman

    1999-01-01

    Many wetland creation and restoration projects have successfully restored or created appropriate hydrologic conditions for the support of wetland ecosystems but have not been as successful in establishing a diverse biota of native wetland vegetation. Recent work in the propagation and transplanting of native wetland plant seedlings offers promise for increasing...

  3. Regional Opportunities and Policy Initiatives for New Venture Creation

    NARCIS (Netherlands)

    I. Verheul (Ingrid); M.A. Carree (Martin); E. Santarelli (Enrico)

    2007-01-01

    textabstractThis paper investigates the determinants of new venture creation across industries and locations for 103 Italian provinces between 1997 and 2003. We allow for differences in regional opportunities across industries and investigate the impact of a range of factors on entrepreneurship in

  4. Progress in strategies for sequence diversity library creation for ...

    African Journals Online (AJOL)

    Protein engineering has been the most attractive strategy for biologists to redesign enzymes. As the simplest technique of protein engineering, directed evolution has been applied to many fields, such as industry, agriculture and medicine. An experiment of directed evolution comprises mutant libraries creation and ...

  5. Customer Experience Creation : Determinants, Dynamics and Management Strategies

    NARCIS (Netherlands)

    Verhoef, Peter C.; Lemon, Katherine N.; Parasuraman, A.; Roggeveen, Anne; Tsiros, Michael; Schlesinger, Leonard A.; Schlessinger, L.L.

    2009-01-01

    Retailers, such as Starbucks and Victoria's Secret, aim to provide customers a great experience across channels, In this paper we provide an overview of the existing literature on customer experience and expand on it to examine the creation of a customer experience front a holistic perspective. We

  6. Training for Template Creation: A Performance Improvement Method

    Science.gov (United States)

    Lyons, Paul

    2008-01-01

    Purpose: There are three purposes to this article: first, to offer a training approach to employee learning and performance improvement that makes use of a step-by-step process of skill/knowledge creation. The process offers follow-up opportunities for skill maintenance and improvement; second, to explain the conceptual bases of the approach; and…

  7. The "Creation-Science" Case and Pro Bono Publico.

    Science.gov (United States)

    Kerr, Peggy L.

    1982-01-01

    Describes contributions and efforts of New York law firm (Skadden, Arps, Slate, Meagher, Flom) personnel in developing plaintiff's case in McLean v. Arkansas 590 (balanced treatment of creationism/evolution). Discusses aspects of "Pro Bono Publico" (unpaid public interest service) endeavors in general and those related to this law firm in…

  8. Goodwill, Excess Returns, and Determinants of Value Creation and Overpayment

    NARCIS (Netherlands)

    Lycklama a Nijeholt, M.; Grift, Y.K.

    2007-01-01

    In this article we have investigated whether the determinants of excess returns (especially of target excess returns) are valid for purchased goodwill as well. Among them are acquirer’s and target’s Tobin’s q, and debt assets ratio, that explain value creation of acquisitions, and relative size,

  9. Curiosity and Its Role in Cross-Cultural Knowledge Creation

    Science.gov (United States)

    Mikhaylov, Natalie S.

    2016-01-01

    This paper explores the role of curiosity in promoting cross-cultural knowledge creation and competence development. It is based on a study with four international higher educational institutions, all of which offer management and business education for local and international students. The reality of multicultural and intercultural relationships…

  10. ORIGIN : Metal creation and evolution from the cosmic dawn

    NARCIS (Netherlands)

    den Herder, Jan-Willem; Piro, Luigi; Ohashi, Takaya; Kouveliotou, Chryssa; Hartmann, Dieter H.; Kaastra, Jelle S.; Amati, L.; Andersen, M. I.; Arnaud, M.; Attéia, J.-L.; Bandler, S.; Barbera, M.; Barcons, X.; Barthelmy, S.; Basa, S.; Basso, S.; Boer, M.; Branchini, E.; Branduardi-Raymont, G.; Borgani, S.; Boyarsky, A.; Brunetti, G.; Budtz-Jorgensen, C.; Burrows, D.; Butler, N.; Campana, S.; Caroli, E.; Ceballos, M.; Christensen, F.; Churazov, E.; Comastri, A.; Colasanti, L.; Cole, R.; Content, R.; Corsi, A.; Costantini, E.; Conconi, P.; Cusumano, G.; de Plaa, J.; De Rosa, A.; Del Santo, M.; Di Cosimo, S.; De Pasquale, M.; Doriese, R.; Ettori, S.; Evans, P.; Ezoe, Y.; Ferrari, L.; Finger, H.; Figueroa-Feliciano, T.; Friedrich, P.; Fujimoto, R.; Furuzawa, A.; Fynbo, J.; Gatti, F.; Galeazzi, M.; Gehrels, N.; Gendre, B.; Ghirlanda, G.; Ghisellini, G.; Gilfanov, M.; Giommi, P.; Girardi, M.; Grindlay, J.; Cocchi, M.; Godet, O.; Guedel, M.; Haardt, F.; den Hartog, R.; Hepburn, I.; Hermsen, W.; Hjorth, J.; Hoekstra, H.; Holland, A.; Hornstrup, A.; van der Horst, A.; Hoshino, A.; in't Zand, J.; Irwin, K.; Ishisaki, Y.; Jonker, P.; Kitayama, T.; Kawahara, H.; Kawai, N.; Kelley, R.; Kilbourne, C.; de Korte, P.; Kusenko, A.; Kuvvetli, I.; Labanti, M.; Macculi, C.; Maiolino, R.; Hesse, M. Mas; Matsushita, K.; Mazzotta, P.; McCammon, D.; Méndez, M.; Mignani, R.; Mineo, T.; Mitsuda, K.; Mushotzky, R.; Molendi, S.; Moscardini, L.; Natalucci, L.; Nicastro, F.; O'Brien, P.; Osborne, J.; Paerels, F.; Page, M.; Paltani, S.; Pedersen, K.; Perinati, E.; Ponman, T.; Pointecouteau, E.; Predehl, P.; Porter, S.; Rasmussen, A.; Rauw, G.; Röttgering, H.; Roncarelli, M.; Rosati, P.; Quadrini, E.; Ruchayskiy, O.; Salvaterra, R.; Sasaki, S.; Sato, K.; Savaglio, S.; Schaye, J.; Sciortino, S.; Shaposhnikov, M.; Sharples, R.; Shinozaki, K.; Spiga, D.; Sunyaev, R.; Suto, Y.; Takei, Y.; Tanvir, N.; Tashiro, M.; Tamura, T.; Tawara, Y.; Troja, E.; Tsujimoto, M.; Tsuru, T.; Ubertini, P.; Ullom, J.; Ursino, E.; Verbunt, F.; van de Voort, F.; Viel, M.; Wachter, S.; Watson, D.; Weisskopf, M.; Werner, N.; White, N.; Willingale, R.; Wijers, R.; Yamasaki, N.; Yoshikawa, K.; Zane, S.

    2012-01-01

    ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions of all abundant elements between C and Ni to red-shifts of z = 10,

  11. ORIGIN: metal creation and evolution from the cosmic dawn

    NARCIS (Netherlands)

    den Herder, J.W.; Piro, L.; Ohashi, T.; Kouveliotou, C.; Hartmann, D.H.; Kaastra, J.S.; Amati, L.; Andersen, M.I.; Arnaud, M.; Atteia, J.-L.; Bandler, S.; Barbera, M.; Barcons, X.; Barthelmy, S.; Basa, S.; Basso, S.; de Boer, M.; Branchini, E.; Branduardi-Raymont, G.; Borgani, S.; Boyarsky, A.; Brunetti, G.; Budtz-Jorgensen, C.; Burrows, D.; Butler, N.; Campana, S.; Caroli, E.; Ceballos, M.; Christensen, F.; Churazov, E.; Comastri, A.; Colasanti, L.; Cole, R.; Content, R.; Corsi, A.; Costantini, E.; Conconi, P.; Cusumano, G.; de Plaa, J.; De Rosa, A.; Del Santo, M.; Di Cosimo, S.; De Pasquale, M.; Doriese, R.; Ettori, S.; Evans, P.; Ezoe, Y.; Ferrari, L.; Finger, H.; Figueroa-Feliciano, T.; Friedrich, P.; Fujimoto, R.; Furuzawa, A.; Fynbo, J.; Gatti, F.; Galeazzi, M.; Gehrels, N.; Gendre, B.; Ghirlanda, G.; Ghisellini, G.; Gilfanov, M.; Giommi, P.; Girardi, M.; Grindlay, J.; Cocchi, M.; Godet, O.; Guedel, M.; Haardt, F.; Hartog, R.; Hepburn, I.; Hermsen, W.; Hjorth, J.; Hoekstra, H.; Holland, A.; Hornstrup, A.; van der Horst, A.; Hoshino, A.; in 't Zand, J.; Irwin, K.; Ishisaki, Y.; Jonker, P.; Kitayama, T.; Kawahara, H.; Kawai, N.; Kelley, R.; Kilbourne, C.; de Korte, P.; Kusenko, A.; Kuvvetli, I.; Labanti, M.; Macculi, C.; Maiolino, R.; Mas Hesse, M.; Matsushita, K.; Mazzotta, P.; McCammon, D.; Méndez, M.; Mignani, R.; Mineo, T.; Mitsuda, K.; Mushotzky, R.; Molendi, S.; Moscardini, L.; Natalucci, L.; Nicastro, F.; O'Brien, P.; Osborne, J.; Paerels, F.; Page, M.; Paltani, S.; Pedersen, K.; Perinati, E.; Ponman, T.; Pointecouteau, E.; Predehl, P.; Porter, S.; Rasmussen, A.; Rauw, G.; Röttgering, H.; Roncarelli, M.; Rosati, P.; Quadrini, E.; Ruchayskiy, O.; Salvaterra, R.; Sasaki, S.; Sato, K.; Savaglio, S.; Schaye, J.; Sciortino, S.; Shaposhnikov, M.; Sharples, R.; Shinozaki, K.; Spiga, D.; Sunyaev, R.; Suto, Y.; Takei, Y.; Tanvir, N.; Tashiro, M.; Tamura, T.; Tawara, Y.; Troja, E.; Tsujimoto, M.; Tsuru, T.; Ubertini, P.; Ullom, J.; Ursino, E.; Verbunt, F.; van de Voort, F.; Viel, M.; Wachter, S.; Watson, D.; Weisskopf, M.; Werner, N.; White, N.; Willingale, R.; Wijers, R.; Yamasaki, N.; Yoshikawa, K.; Zane, S.

    2012-01-01

    ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions of all abundant elements between C and Ni to red-shifts of z = 10,

  12. Euroasian Integration Process and Effective Institutional Mechanism Creation Problems

    Directory of Open Access Journals (Sweden)

    Olga M. Mesheriakova

    2014-06-01

    Full Text Available In the present article "Euroasian Integration Process and Effective Institutional Mechanism Creation Problems" author investigates the problem of effective and balanced decision-making mechanism in the integration communities creation. Process of the Customs union creation on the Euroasian space began relatively long ago. Creation of such union was started by the Russian Federation and the Republic of Belarus in the 1995. The same year Republic of Kazakhstan joined an integration process. A little later Kyrgyzstan and Tajikistan joined the Customs union – in 1996 and in 1999 respectively. Author on the basis of careful study of the decision-making mechanisms in the Customs union, CIS, EurAsEC and EU, carries out the comparative analysis of the specified mechanisms. Author conducts detailed analytics, gives opinions of jurists, state and public figures, proves own opinions. On the basis of the comparative research conducted by the author the criteria of legal mechanism of decision-making in the integration process efficiency are researched and discussed, what allows to speak about the integration of the legal system. At the end of the article author draws a conclusion that coordination of sovereign desires of states in the integration community represents difficult and many-sided process which has to be based on the balanced decision-making mechanism, which is a main criterion of the institutional mechanism of integration efficiency.

  13. Clergy Views on Evolution, Creationism, Science, and Religion

    Science.gov (United States)

    Colburn, Alan; Henriques, Laura

    2006-01-01

    Spurred by students who felt conflicted accepting evolution and the tenets of their faiths, yet knowing their faiths supported science and evolution, we began a study to determine the views clergy espouse on issues related to evolution, creationism, science, and religion. The resulting study included structured interviews with eight clergy and a…

  14. Creationism in the Classroom: A Controversy with Serious Consequences

    Science.gov (United States)

    Baker, Sylvia

    2010-01-01

    The resignation of the Revd Professor Michael Reiss from his position as Director of Education at the Royal Society over the issue of the teaching of creationism in school science classes provides the background to this article. The immediate controversy is described and considered in relation to its wider context and to the serious questions that…

  15. The Teaching of Evolution and Creationism in Minnesota

    Science.gov (United States)

    Moore, Randy; Kraemer, Karen

    2005-01-01

    The evolution-related attitudes and actions of Minnesota high school biology teachers were studied to estimate the prevalence of creationism among biology teachers. Minnesota's high school biology teachers were questioned about the evolution education in public schools regarding the percentage of biology teachers who teach evolution, class-time…

  16. Contentious Curricula: Afrocentrism and Creationism in American Public Schools.

    Science.gov (United States)

    Binder, Amy J.

    This book compares two groups of citizens who challenged U.S. public school curricula in the 1980s and identities striking similarities between proponents of Afrocentrism and creationism, accounts for differential outcomes, and draws conclusions for the study of culture, organizations, and social movements. The chapters are (1) Introduction to…

  17. Should Creationism Be Taught in the Public Schools?

    Science.gov (United States)

    Pennock, Robert T.

    2002-01-01

    Discusses philosophical arguments relevant to the question of teaching creationism, especially with regard to developments in the debate since the early 1990s. Considers what the relevant differences for the policy question for private, public schools, and home schoolers are. Discusses the main legal arguments that have ruled in the case of public…

  18. Science and Creationism: A Response to Kenneth Tobin

    Science.gov (United States)

    Alexakos, Konstantinos

    2009-01-01

    In his December editorial on Michael Reiss, Kenneth Tobin ("Cult Stud Sci Educ" 3:793-798, 2008), raises some very important questions for science and science teachers regarding science education and the teaching of creationism in the classroom. I agree with him that students' creationist ideologies should be treated not as misconceptions but as…

  19. The Complete Information Literacy? Unforgetting Creation and Organization of Information

    Science.gov (United States)

    Huvila, Isto

    2011-01-01

    Even though the concept of information literacy typically embraces an idea of a complete participation in an information community, its definitions have tended to underline the phases of seeking, searching and evaluation instead of creating information. Shortcomings of information creation can, however, explain many of the difficulties of finding…

  20. The Creation of Districts and Constituencies in Ghana: Some ...

    African Journals Online (AJOL)

    political issues emanating from the procedures for the creation of districts and constituencies and concludes that they should be streamlined. Keywords: Boundary Demarcation, District, Constituency. ' Professor, Department of Geography and Resource Development, University of Ghana. E-mail: rhening2008gmail .com.

  1. The Politics of States', Local Governments' Creation and Nigeria's ...

    African Journals Online (AJOL)

    Nekky Umera

    which posits that for a federation to be stable the component parts must be fairly equal in size. Coupled with minorities' fear of marginalization, the quest by Nigerians, most especially the minorities, for the creation of their dream states has reached a crescendo. Thus, continuing fragmentation of the polity at intervals have ...

  2. The Relationship between Firm Births and Job Creation

    NARCIS (Netherlands)

    A.J. van Stel (André); D. Storey (David)

    2002-01-01

    textabstractThis paper examines the relationship between firm births and job creation in Great Britain. We use a new data set for 60 British regions, covering the whole of Great Britain, between 1980 and 1998. The central theme of the paper is that, with the exception of a recent paper by Audretsch

  3. Creation evidence of the second non-dispersive Zakharenko wave ...

    Indian Academy of Sciences (India)

    In this work, the experimental results of the creation of the second non-dispersive Zakharenko wave (ph = g ≠ 0) in the negative roton branch (the so-called second sound) of the bulk elementary excitations (BEEs) energy spectra are introduced. Several BEE signals detected by a bolometer situated in the isotopically ...

  4. \\'The snake will swallow you': supernatural snakes and the creation ...

    African Journals Online (AJOL)

    \\'The snake will swallow you': supernatural snakes and the creation of the Khotso legend. Felicity Wood. Abstract. No Abstract. Indilinga: African Journal of Indigenous Knowledge Systems (IAJIKS) Vol. 4(1) 2005: 347-359. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  5. The relation between creation and salvation in the Trinitarian ...

    African Journals Online (AJOL)

    This article explored the relation between creation and salvation as acts of God in the theology of Robert Jenson, an American Lutheran theologian. This is important due to Jenson's growing importance as theologian and because of the current importance of ecotheology (and related themes that were implicated by the ...

  6. The Challenges of Collaborative Knowledge Creation in Open Innovation Teams

    Science.gov (United States)

    Du Chatenier, Elise; Verstegen, Jos A. A. M.; Biemans, Harm J. A.; Mulder, Martin; Omta, Onno

    2009-01-01

    In open innovation teams, people from different organizations work together to develop new products, services, or markets. This organizational diversity can positively influence collaborative knowledge creation but can frustrate and obstruct the process as well. To increase the success rates of open innovation, it is vital to learn how individuals…

  7. IT-Enabled Knowledge Creation for Open Innovation

    NARCIS (Netherlands)

    Eseryel, U. Yeliz

    2014-01-01

    Open innovation is increasingly important for researchers and practitioners alike. Open innovation is closely linked to knowledge creation in that, with open innovation, knowledge inflows and outflows are exploited for innovation. In the information systems field, open innovation has been closely

  8. How to manage enterprise? From creation to rational continuation

    NARCIS (Netherlands)

    Hans Broekhuis; Louise van Weerden

    2009-01-01

    There is a difference between enterprise and management. Enterprise is about creation and management is the rational continuation of enterprise. Being rational comes natural to entrepreneurs, but a good entrepreneur has to develop both aspects. To achieve this is an important aspect of management

  9. Leading Innovation and Change: Knowledge Creation by Schools for Schools

    Science.gov (United States)

    Harris, Alma

    2008-01-01

    This article explores the process and practice of knowledge creation within development and research (D and R) networks. It focuses upon D and R networks in England that are currently engaged in collaboration and innovation. Early evaluative evidence suggests that D and R school networks offer "spaces" for collaborative working, mutual…

  10. The Creation of Districts and Constituencies in Ghana: Some ...

    African Journals Online (AJOL)

    law make provision for the redrawing of the boundaries of districts or for reconstituting ... "(2) The President may by executive instrument -. (a) declare ... article." Provision was made for persons who are dissatisfied with the decisions of the Electoral Commission on the creation of constituencies to seek redress. Article 48 of ...

  11. Filipino au pairs on the move

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2016-01-01

    interdependence, whilst they continuously form their trajectories in relation to opportunities and restraints posed along the way by their local and transnational social relations. The article argues that examinations of migration trajectories benefit from broadening the research out in both time and space......Most Filipina au pairs in Denmark send remittances back home, and for many, au pairing forms part of longer-term migration trajectories. This article explores how Filipina au pairs try to carve out a future for themselves abroad. It shows that they navigate within tight webs of financial...

  12. Becoming independent through au pair migration

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2015-01-01

    . This article argues that, despite this critique, au pairing does play an important formative role for young Filipinas because it opens up for experiences abroad that enable them to be recognised as independent adults in Philippine society. Rather than autonomy, however, au pairs define their independence...... in terms of their capacity to assume responsibility for others, thereby achieving a position of social respect. Based on ethnographic fieldwork in Denmark and the Philippines, this article explores how young Filipinas use the social, economic, and cultural resources they gain from their au pair stay abroad...

  13. Pairing symmetries in cuprates: A Gorkov formalism

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Angsula, E-mail: angsula@ufam.edu.br [Departamento de Fisica, UFAM, Av. Rodrigo Octavio 3000, Japiim, 69077-000 Manaus, AM (Brazil); Pimentel, B.M. [Instituto de Fisica Teorica, Sao Paulo State University, P.O. Box 70532-2, 01156-970 Sao Paulo, SP (Brazil)

    2012-10-01

    Inspite of the direct evidence for Cooper pairing in the cuprates as in conventional superconductors, the pairing symmetry in the cuprate superconductors is still considered to be a controversial and a highly debatable topic. The microscopic equations appropriate for these new materials, essentially the yttrium based compounds, are discussed following Gorkov's formalism for the conventional superconductors. Various types of symmetry of the pairing parameter are considered. In this study we consider the anisotropic nature of the gap parameter to write the mean-field equations of the cuprates. We observe that the symmetry of the potential is fundamental in deciding the nature of the anisotropy in the gap parameter.

  14. English for au pairs the au pair's guide to learning English

    CERN Document Server

    Curtis, Lucy

    2014-01-01

    English for Au Pairs has interlinked stories about a group of au pairs new to England. Marta, an 18-year-old from Poland arrives in the UK to work as an au pair. Throughout her year-long stay she has many different experiences - some bad, some good - but with the support of her host family she finds new friends and improves her English. English for Au Pairs offers insight into the joys and difficulties of being an au pair while at the same time reinforcing English language learning through grammar explanations and exercises.

  15. The Creation of the world and the birth of chronology

    Science.gov (United States)

    Richet, Pascal

    2017-09-01

    The eternity of the world and, correlatively, the cyclical nature of time were agreed upon by all Greek philosophical schools except the Platonists. As for matter, all of them posited that it was eternal so that the idea that something could be made from nothing was considered as pure absurdity. With the advent of Christianity, however, a matter coeternal with God raised fundamental theological difficulties. Toward the end of the second century, apologists such as Tatian the Assyrian, Theophilus of Antioch, Irenaeus of Lyons or Tertullian thus emphasized God's absolute freedom and power by claiming that Creation had been made from nothing. Along with the Passion of Christ and the Last Judgment, the initial moment defined by the Creation then conferred to time an irreversible, linear orientation and to history both a new sense and an obsessing concern for chronology. Unambiguously, the Creation became the reference point for the world's history. From Scripture analyses, one determined that it took place about 5500 years earlier within a framework where the History of man and that of the earth were not distinct. Having designed a consistent, universal time scale from chronological data recorded for all ancient peoples, Eusebius of Caesarea could thus attribute to the Great Flood the fossils found on the top of Mount Lebanon. The short Mosaic chronologies were eventually rejected during the 18th century, but Eusebius' chronological procedure was unknowingly transposed when a relative geological timescale was then set up from the fossil record. The close association of Creation with Christian dogma in turn induced some circles to reject the second law of thermodynamics at the end of the 19th century and, a few decades later, the thesis of an expanding universe. In both cases, the reason was that continuously increasing entropy would imply some low-entropy initial state akin to a Creation.

  16. Value Creation Challenges in Multichannel Retail Business Models

    Directory of Open Access Journals (Sweden)

    Mika Yrjölä

    2014-08-01

    Full Text Available Purpose: The purpose of the paper is to identify and analyze the challenges of value creation in multichannel retail business models. Design/methodology/approach: With the help of semi-structured interviews with top executives from different retailing environments, this study introduces a model of value creation challenges in the context of multichannel retailing. The challenges are analyzed in terms of three retail business model elements, i.e., format, activities, and governance. Findings: Adopting a multichannel retail business model requires critical rethinking of the basic building blocks of value creation. First of all, as customers effortlessly move between multiple channels, multichannel formats can lead to a mismatch between customer and firm value. Secondly, retailers face pressures to use their activities to form integrated total offerings to customers. Thirdly, multiple channels might lead to organizational silos with conflicting goals. A careful orchestration of value creation is needed to determine the roles and incentives of the channel parties involved. Research limitations/implications: In contrast to previous business model literature, this study did not adopt a network-centric view. By embracing the boundary-spanning nature of the business model, other challenges and elements might have been discovered (e.g., challenges in managing relationships with suppliers. Practical implications: As a practical contribution, this paper has analyzed the challenges retailers face in adopting multichannel business models. Customer tendencies for showrooming behavior highlight the need for generating efficient lock-in strategies. Customized, personal offers and information are ways to increase customer value, differentiate from competition, and achieve lock-in. Originality/value: As a theoretical contribution, this paper empirically investigates value creation challenges in a specific context, lowering the level of abstraction in the mostly

  17. Introducing a model of pairing based on base pair specific interactions between identical DNA sequences

    Science.gov (United States)

    (O’ Lee, Dominic J.

    2018-02-01

    At present, there have been suggested two types of physical mechanism that may facilitate preferential pairing between DNA molecules, with identical or similar base pair texts, without separation of base pairs. One mechanism solely relies on base pair specific patterns of helix distortion being the same on the two molecules, discussed extensively in the past. The other mechanism proposes that there are preferential interactions between base pairs of the same composition. We introduce a model, built on this second mechanism, where both thermal stretching and twisting fluctuations are included, as well as the base pair specific helix distortions. Firstly, we consider an approximation for weak pairing interactions, or short molecules. This yields a dependence of the energy on the square root of the molecular length, which could explain recent experimental data. However, analysis suggests that this approximation is no longer valid at large DNA lengths. In a second approximation, for long molecules, we define two adaptation lengths for twisting and stretching, over which the pairing interaction can limit the accumulation of helix disorder. When the pairing interaction is sufficiently strong, both adaptation lengths are finite; however, as we reduce pairing strength, the stretching adaptation length remains finite but the torsional one becomes infinite. This second state persists to arbitrarily weak values of the pairing strength; suggesting that, if the molecules are long enough, the pairing energy scales as length. To probe differences between the two pairing mechanisms, we also construct a model of similar form. However, now, pairing between identical sequences solely relies on the intrinsic helix distortion patterns. Between the two models, we see interesting qualitative differences. We discuss our findings, and suggest new work to distinguish between the two mechanisms.

  18. Correlated electron pairs in metal clusters

    Science.gov (United States)

    Iachello, F.; Lipparini, E.; Ventura, A.

    We show that the experimental data on ionization energies and photoabsorption cross sections of alkali metal clusters are consistent with a model of clusters in terms of a system of interacting electron pairs with L=0 and L=2.

  19. Four square mile survey pair count instructions

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This standard operating procedure (SOP) provides guidance for conducting bird pair count measurements on wetlands for the HAPETs Four-Square-Mile survey. This set of...

  20. Pairing properties of realistic effective interactions

    Directory of Open Access Journals (Sweden)

    Gargano A.

    2016-01-01

    Full Text Available We investigate the pairing properties of an effective shell-model interaction defined within a model space outside 132Sn and derived by means of perturbation theory from the CD-Bonn free nucleon-nucleon potential. It turns out that the neutron pairing component of the effective interaction is significantly weaker than the proton one, which accounts for the large pairing gap difference observed in the two-valence identical particle nuclei 134Sn and 134Te. The role of the contribution arising from one particle-one hole excitations in determining the pairing force is discussed and its microscopic structure is also analyzed in terms of the multipole decomposition.

  1. Microfluidic Control of Cell Pairing and Fusion

    Science.gov (United States)

    Skelley, Alison M.; Kirak, Oktay; Suh, Heikyung; Jaenisch, Rudolf; Voldman, Joel

    2011-01-01

    Cell fusion has been used for many different purposes, including generation of hybridomas and reprogramming of somatic cells. The fusion step represents the key event in initiation of these procedures. Standard fusion techniques, however, provide poor and random cell contact, leading to low yields. We present here a microfluidic device to trap and properly pair thousands of cells. Using this device we were able to pair different cell types, including fibroblasts, mouse embryonic stem cells (mESCs), and myeloma cells, achieving pairing efficiencies up to 70%. The device is compatible with both chemical and electrical fusion protocols. We observed that electrical fusion was more efficient than chemical fusion, with membrane reorganization efficiencies of up to 89%. We achieved greater than 50% properly paired and fused cells over the entire device, 5× greater than a commercial electrofusion chamber, and were able to observe reprogramming in hybrids between mESCs and mouse embryonic fibroblasts. PMID:19122668

  2. Temporal Multimode Storage of Entangled Photon Pairs.

    Science.gov (United States)

    Tiranov, Alexey; Strassmann, Peter C; Lavoie, Jonathan; Brunner, Nicolas; Huber, Marcus; Verma, Varun B; Nam, Sae Woo; Mirin, Richard P; Lita, Adriana E; Marsili, Francesco; Afzelius, Mikael; Bussières, Félix; Gisin, Nicolas

    2016-12-09

    Multiplexed quantum memories capable of storing and processing entangled photons are essential for the development of quantum networks. In this context, we demonstrate and certify the simultaneous storage and retrieval of two entangled photons inside a solid-state quantum memory and measure a temporal multimode capacity of ten modes. This is achieved by producing two polarization-entangled pairs from parametric down-conversion and mapping one photon of each pair onto a rare-earth-ion-doped (REID) crystal using the atomic frequency comb (AFC) protocol. We develop a concept of indirect entanglement witnesses, which can be used as Schmidt number witnesses, and we use it to experimentally certify the presence of more than one entangled pair retrieved from the quantum memory. Our work puts forward REID-AFC as a platform compatible with temporal multiplexing of several entangled photon pairs along with a new entanglement certification method, useful for the characterization of multiplexed quantum memories.

  3. Z-related pairs in microtonal systems

    NARCIS (Netherlands)

    Althuis, T.A.; Gobel, F.

    2000-01-01

    Various infinite families of Z-related pairs in microtonal systems are presented. Soderberg's dual inversion is compared to a more special transformation, the one-pitch shift. The material is illustrated by several examples.

  4. 22 CFR 62.31 - Au pairs.

    Science.gov (United States)

    2010-04-01

    ....31 Au pairs. (a) Introduction. This section governs Department of State-designated exchange visitor... requirements set forth at § 62.10 sponsors shall: (1) Inform all host families of the philosophy, rules, and...

  5. Alloy solution hardening with solute pairs

    Science.gov (United States)

    Mitchell, John W.

    1976-08-24

    Solution hardened alloys are formed by using at least two solutes which form associated solute pairs in the solvent metal lattice. Copper containing equal atomic percentages of aluminum and palladium is an example.

  6. Degenerated differential pair with controllable transconductance

    NARCIS (Netherlands)

    Mensink, Clemens; Mensink, Clemens H.J.; Nauta, Bram

    1998-01-01

    A differential pair with input transistors and provided with a variable degeneration resistor. The degeneration resistor comprises a series arrangement of two branches of coupled resistors which are shunted in mutually corresponding points by respective control transistors whose gates are

  7. a Norm Pairing in Formal Modules

    Science.gov (United States)

    Vostokov, S. V.

    1980-02-01

    A pairing of the multiplicative group of a local field (a finite extension of the field of p-adic numbers Qp) with the group of points of a Lubin-Tate formal group is defined explicitly. The values of the pairing are roots of an isogeny of the formal group. The main properties of this pairing are established: bilinearity, invariance under the choice of a local uniformizing element, and independence of the method of expanding elements into series with respect to this uniformizing element. These properties of the pairing are used to prove that it agrees with the generalized Hilbert norm residue symbol when the field over whose ring of integers the formal group is defined is totally ramified over Qp. This yields an explicit expression for the generalized Hilbert symbol on the group of points of the formal group. Bibliography: 12 titles.

  8. Pairing dynamics and the origin of species

    OpenAIRE

    Puebla, Oscar; Bermingham, Eldredge; Guichard, Frédéric

    2011-01-01

    Whether sexual selection alone can drive the evolution of assortative mating in the presence of gene flow is a long-standing question in evolutionary biology. Here, we report a role for pairing dynamics of individuals when mate choice is mutual, which is sufficient for the evolution of assortative mating by sexual selection alone in the presence of gene flow. Through behavioural observation, individual-based simulation and population genetic analysis, we evaluate the pairing dynamics of coral...

  9. Marcus Theory of Ion-Pairing

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Santanu; Baer, Marcel D.; Mundy, Christopher J.; Schenter, Gregory K.

    2017-08-08

    We present a theory for ion pair dissociation and association, motivated by the concepts of the Marcus theory of electron transfer. Despite the extensive research on ion-pairing in many chemical and biological processes, much can be learned from the exploration of collective reaction coordinates. To this end, we explore two reaction coordinates, ion pair distance and coordination number. The study of the correlation between these reaction coordinates provides a new insight into the mechanism and kinetics of ion pair dissociation and association in water. The potential of mean force on these 2D-surfaces computed from molecular dynamics simulations of different monovalent ion pairs reveal a Marcus-like mechanism for ion-pairing: Water molecules rearrange forming an activated coordination state prior to ion pair dissociation or association, followed by relaxation of the coordination state due to further water rearrangement. Like Marcus theory, we find the existence of an inverted region where the transition rates are slower with increasing exergonicity. This study provides a new perspective for the future investigations of ion-pairing and transport. SR, CJM, and GKS were supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. MDB was supported by MS3 (Materials Synthesis and Simulation Across Scales) Initiative, a Laboratory Directed Research and Development Program at Pacific Northwest National Laboratory (PNNL). The research was performed using PNNL Institutional Computing. PNNL is a multi-program national laboratory operated by Battelle for the U.S. Department of Energy.

  10. The grammar of approximating number pairs.

    Science.gov (United States)

    Eriksson, Kimmo; Bailey, Drew H; Geary, David C

    2010-04-01

    In the present article, we studied approximating pairs of numbers (a, b) that were used to estimate quantity in a single phrase ("two, three years ago"). Pollmann and Jansen (1996) found that only a few of the many possible pairs are actually used, suggesting an interaction between the ways in which people estimate quantity and their use of quantitative phrases in colloquial speech. They proposed a set of rules that describe which approximating pairs are used in Dutch phrases. We revisited this issue in an analysis of Swedish and American language corpora and in a series of three experiments in which Swedish and American adults rated the acceptability of various approximating pairs and created approximating pairs of their own in response to various estimation tasks. We found evidence for Pollmann and Jansen's rules in both Swedish and English phrases, but we also identified additional rules and substantial individual and cross-language variation. We will discuss implications for the origin of this loose "grammar" of approximating pairs.

  11. Formation of asteroid pairs by rotational fission.

    Science.gov (United States)

    Pravec, P; Vokrouhlický, D; Polishook, D; Scheeres, D J; Harris, A W; Galád, A; Vaduvescu, O; Pozo, F; Barr, A; Longa, P; Vachier, F; Colas, F; Pray, D P; Pollock, J; Reichart, D; Ivarsen, K; Haislip, J; Lacluyze, A; Kusnirák, P; Henych, T; Marchis, F; Macomber, B; Jacobson, S A; Krugly, Yu N; Sergeev, A V; Leroy, A

    2010-08-26

    Pairs of asteroids sharing similar heliocentric orbits, but not bound together, were found recently. Backward integrations of their orbits indicated that they separated gently with low relative velocities, but did not provide additional insight into their formation mechanism. A previously hypothesized rotational fission process may explain their formation-critical predictions are that the mass ratios are less than about 0.2 and, as the mass ratio approaches this upper limit, the spin period of the larger body becomes long. Here we report photometric observations of a sample of asteroid pairs, revealing that the primaries of pairs with mass ratios much less than 0.2 rotate rapidly, near their critical fission frequency. As the mass ratio approaches 0.2, the primary period grows long. This occurs as the total energy of the system approaches zero, requiring the asteroid pair to extract an increasing fraction of energy from the primary's spin in order to escape. We do not find asteroid pairs with mass ratios larger than 0.2. Rotationally fissioned systems beyond this limit have insufficient energy to disrupt. We conclude that asteroid pairs are formed by the rotational fission of a parent asteroid into a proto-binary system, which subsequently disrupts under its own internal system dynamics soon after formation.

  12. Kinetics of electron-positron pair plasmas using an adaptive Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Pilla, R.P.; Shaham, J. [Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027 (United States)

    1997-09-01

    A new algorithm for implementing the adaptive Monte Carlo method is given. It is used to solve the Boltzmann equations that describe the time evolution of a nonequilibrium electron-positron pair plasma containing high-energy photons. These are coupled nonlinear integro-differential equations. The collision kernels for the photons as well as pairs are evaluated for Compton scattering, pair annihilation and creation, bremsstrahlung, and Coulomb collisions. They are given as multidimensional integrals which are valid for all energies. For an homogeneous and isotropic plasma with no particle escape, the equilibrium solution is expressed analytically in terms of the initial conditions. For two specific cases, for which the photon and the pair spectra are initially constant or have a power-law distribution within the given limits, the time evolution of the plasma is analyzed using the new method. The final spectra are found to be in a good agreement with the analytical solutions. The new algorithm is faster than the Monte Carlo scheme based on uniform sampling and more flexible than the numerical methods used in the past, which do not involve Monte Carlo sampling. It is also found to be very stable. Some astrophysical applications of this technique are discussed. {copyright} {ital 1997} {ital The American Astronomical Society}

  13. Measurement of Angular Correlation in b Quark Pair Production at the LHC as a Test of Perturbative QCD

    CERN Document Server

    Dorney, Brian Lee

    2013-01-01

    Beauty quarks are pair-produced by strong interactions in multi-TeV proton- proton (pp) collisions at the CERN Large Hadron Collider (LHC). Such interactions allow for a test of perturbative Quantum Chromodynamics (QCD) in a new energy regime. The primary beauty-antibeauty quark b b pair production mechanisms in perturbative QCD are referred to as avor creation, avor excitation, and gluon splitting. These three mechanisms produce b b pairs with characteristic kinematic behavior, which contribute dierently to the shape of the dierential b b production cross section with respect to the dierence in the azimuthal angle and the combined separation variable R = p 2 + 2 between the beauty and antibeauty quarks ( b and b , respectively); with being the change in the pseudorapidity = ln ( tan ( = 2)), being the polar angle. These and R variables are collectively referred to as angular correlation variables and hence forth referred to as A . By measuring the shape and absolute normalization of the dierential prod...

  14. Generalized pairing strategies-a bridge from pairing strategies to colorings

    Directory of Open Access Journals (Sweden)

    Győrffy Lajos

    2016-12-01

    Full Text Available In this paper we define a bridge between pairings and colorings of the hypergraphs by introducing a generalization of pairs called t-cakes for t ∈ ℕ, t ≥ 2. For t = 2 the 2-cakes are the same as the well-known pairs of system of distinct representatives, that can be turned to pairing strategies in Maker-Breaker hypergraph games, see Hales and Jewett [12]. The two-colorings are the other extremity of t-cakes, in which the whole ground set of the hypergraph is one big cake that we divide into two parts (color classes. Starting from the pairings (2-cake placement and two-colorings we define the generalized t-cake placements where we pair p elements by q elements (p, q ∈ ℕ, 1 ≤ p, q < t, p + q = t.

  15. Translation Collective and Illustration: aesthetic film creation from Jane Austen

    Directory of Open Access Journals (Sweden)

    Lemuel da Cruz Gandara

    2015-08-01

    Full Text Available http://dx.doi.org/10.5007/2175-7917.2015v20n2p67 From metonymic clippings of the novels Sense and Sensibility (1811, Pride and Prejudice (1813, Emma (1815 and Persuasion (1817, all written by the English author Jane Austen (1775-1817, we propose a comparative analysis among the literary texts, the illustrations by Hugh Thomson at the end of the nineteenth century and the film footage created between 1995 and 2005. Our goal is to confront tickets to find similarities and differences dialogic between them. This perspective reveals the interpretations made by many readers over the years and the receptions of the English writer in different contexts and media. Our critical and theoretical reflection is based on studies of the Russian philosopher Mikhail Bakhtin about the aesthetics of literary creation and amplifies the concepts of literary cinema, collective translation and aesthetics of film creation.

  16. Experimental progress toward single phonon creation in a mechanical resonator

    Science.gov (United States)

    O'Connell, Aaron; Ansmann, M.; Bialczak, R. C.; Hofheinz, M.; Lucero, E.; Neeley, M.; Sank, D.; Wang, H.; Wenner, J.; Martinis, J. M.; Cleland, A. N.

    2009-03-01

    Coupling a high frequency (˜6 GHz) mechanical resonator to a Josephson phase qubit may enable the creation and manipulation of single phonons. Previously, we have shown the creation of arbitrary photon states in a superconducting coplanar waveguide (CPW) resonator coupled to a phase qubit (Max Hofheinz et al., Nature 454, 310-314, 2008). That experiment illustrated the capability of the phase qubit to controllably create and measure quantum states in a capacitively coupled resonator. By replacing the CPW resonator with a film bulk acoustic resonator (FBAR) we can potentially transfer the quantum state of the phase qubit to a vibrational mode of the FBAR. This talk will focus on our experimental progress to date in realizing this aim.

  17. PROBLEMS AND POTENTIALS IN THE CREATION OF NEW OBJECTS

    DEFF Research Database (Denmark)

    Juhl, Joakim; Gylling, Martin

    2011-01-01

    theories we will argue the importance of problems in change-making processes. We will emphasize on how processes of creative thinking and innovation is done in steps, and how the end result reflects what these steps have brought in terms of problem perception and new knowledge. Inspired by concepts from......In this paper we will based on two case studies, explore the creation of new objects in two very different contexts, being the art of painting and the fluid-mechanical engineering. From an empirical point of view we will treat creativity through actor-context relations, which enclose perceptions...... of problems. This kind of context is capturing a duality as both being a stabilizing structure, difficult to escape from, but also serving as the condition upon which to create something. This duality appears to be a critical and necessary condition for the creation of something new. Through different social...

  18. Problems and Potentials in the Creation of New Objects

    DEFF Research Database (Denmark)

    Gylling, Martin; Juhl, Joakim

    2011-01-01

    theories we will argue the importance of problems in change-making processes. We will emphasize on how processes of creative thinking and innovation is done in steps, and how the end result reflects what these steps have brought in terms of problem perception and new knowledge. Inspired by concepts from......In this paper we will based on two case studies, explore the creation of new objects in two very different contexts, being the art of painting and the fluid-mechanical engineering. From an empirical point of view we will treat creativity through actor-context relations, which enclose perceptions...... of problems. This kind of context is capturing a duality as both being a stabilizing structure, difficult to escape from, but also serving as the condition upon which to create something. This duality appears to be a critical and necessary condition for the creation of something new. Through different social...

  19. The biblical creation accounts and evolution: A catholic perspective*

    Directory of Open Access Journals (Sweden)

    Patrick J. Hartin

    1989-03-01

    Full Text Available Faith and reason are not two conflicting sources for knowledge. Truth is one, and both faith and reason try to give an understanding of the truth from different perspectives which are not necessarily contradictory. This is illustrated by means of an issue that is often presented as an area of conflict between faith and science, namely creation and evolution. Using the methods of historical criticism, and examination of the biblical creation accounts is undertaken. The purpose is to ascertain the message of these accounts with regard to God and humanity. A further examination is made to see how this message has been understood over the centuries in the context of Roman Catholic tradition. Finally, the attempt will be made to show how an understanding of evolution can be harmonised with what Scripture teaches and the way it has been appropriated over the centuries.

  20. Descartes on the Creation of the Eternal Truths

    Directory of Open Access Journals (Sweden)

    Danielle Macbeth

    2017-06-01

    Full Text Available On 15 April 1630, in a letter to Mersenne, Descartes announced that on his view God creates the truths of mathematics. Descartes returned to the theme in subsequent letters and some of his Replies but nowhere is the view systematically developed and defended. It is not clear why Descartes came to espouse the creation doctrine, nor even what exactly it is. Some have argued that his motivation was theological, that God creates the eternal truths, including the truths of logic, because and insofar as God is omnipotent andthe creator of all things. I develop and defend a different reading according to which Descartes was led to espouse the creation doctrine by a fundamental shift in his understanding of the correct mode of inquiry in metaphysics and mathematics: by 1630, the God-created truths came to play the role in inquiry that until then, in the Rules for the Direction of the Mind, had been played by images.