WorldWideScience

Sample records for binding energy shifts

  1. First-principles calculation of core-level binding energy shift in surface chemical processes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Combined with third generation synchrotron radiation light sources, X-ray photoelectron spectroscopy (XPS) with higher energy resolution, brilliance, enhanced surface sensitivity and photoemission cross section in real time found extensive applications in solid-gas interface chemistry. This paper reports the calculation of the core-level binding energy shifts (CLS) using the first-principles density functional theory. The interplay between the CLS calculations and XPS measurements to uncover the structures, adsorption sites and chemical reactions in complex surface chemical processes are highlight. Its application on clean low index (111) and vicinal transition metal surfaces, molecular adsorption in terms of sites and configuration, and reaction kinetics are domonstrated.

  2. Accurate core-electron binding energy shifts from density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Takahata, Yuji, E-mail: taka@iqm.unicamp.b [Amazonas State University, School of Engineering, Av. Darcy Vargas, 1200, Parque 10 - CEP 69065-020, Manaus, Amazonas (Brazil); Department of Chemistry, University of Campinas-UNICAMP, Campinas 13084-862, Sao Paulo (Brazil); Marques, Alberto Dos Santos [Amazonas State University, School of Engineering, Av. Darcy Vargas, 1200, Parque 10 - CEP 69065-020, Manaus, Amazonas (Brazil)

    2010-05-15

    Current review covers description of density functional methods of calculation of accurate core-electron binding energy (CEBE) of second and third row atoms; applications of calculated CEBEs and CEBE shifts (DELTACEBEs) in elucidation of topics such as: hydrogen-bonding, peptide bond, polymers, DNA bases, Hammett substituent (sigma) constants, inductive and resonance effects, quantitative structure activity relationship (QSAR), and solid state effect (WD). This review limits itself to works of mainly Chong and his coworkers for the period post-2002. It is not a fully comprehensive account of the current state of the art.

  3. Positive XPS binding energy shift of supported Cu{sub N}-clusters governed by initial state effects

    Energy Technology Data Exchange (ETDEWEB)

    Peters, S.; Peredkov, S. [Technische Universität Berlin, IOAP, Strasse des 17. Juni 135, 10623 Berlin (Germany); Al-Hada, M. [Department of Physics, College of Education and Linguistics, University of Amran (Yemen); Neeb, M., E-mail: matthias.neeb@helmholtz-berlin.de [Helmholtz-Zentrum Berlin, Wilhelm-Conrad-Röntgen-Campus Adlershof, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin (Germany); Eberhardt, W. [Technische Universität Berlin, IOAP, Strasse des 17. Juni 135, 10623 Berlin (Germany); DESY, Center for Free Electron Laser Science (CFEL), Notkestr. 85, 22607 Hamburg (Germany)

    2014-01-01

    Highlights: • Size dependent initial and final state effects of mass-selected deposited clusters. • Initial state effect dominates positive XPS shift in supported Cu-clusters. • Size dependent Coulomb correlation shift in the Auger final state of Cu cluster. • Size-dependent Auger parameter analysis. • Positive XPS shift differs from negative surface core level shift in crystalline copper. - Abstract: An initial state effect is established as origin for the positive 2p core electron binding energy shift found for Cu{sub N}-clusters supported by a thin silica layer of a p-doped Si(1 0 0) wafer. Using the concept of the Auger parameter and taking into account the usually neglected Coulomb correlation shift in the Auger final state (M{sub 4,5}M{sub 4,5}) it is shown that the initial state shift is comparable to the measured XPS shift while the final state relaxation shift contributes only marginally to the binding energy shift. The cluster results differ from the negative surface core-level shift of crystalline copper which has been explained in terms of a final state relaxation effect.

  4. The Shifts of Band Gap and Binding Energies of Titania/Hydroxyapatite Material

    Directory of Open Access Journals (Sweden)

    Nguyen Thi Truc Linh

    2014-01-01

    Full Text Available The titania/hydroxyapatite (TiO2/HAp product was prepared by precipitating hydroxyapatite in the presence of TiO(OH2 gel in the hydrothermal system. The characteristics of the material were determined by using the measurements such as X-ray photoemission spectroscopy (XPS, X-ray diffraction (XRD, diffuse reflectance spectra (DRS, transmission electron microscopy (TEM, scanning electron microscopy (SEM, and energy dispersive X-ray (EDX. The XPS analysis showed that the binding energy values of Ca (2p1/2, 2p3/2, P (2p1/2, 2p3/2, and O 1s levels related to hydroxyapatite phase whereas those of Ti (2p3/2, 2p1/2 levels corresponded with the characterization of titanium (IV in TiO2. The XRD result revealed that TiO2/HAp sample had hydroxyapatite phase, but anatase or rutile phases were not found out. TEM image of TiO2/HAp product showed that the surface of the plate-shaped HAp particles had a lot of smaller particles which were considered as the compound of Ti. The experimental band gap of TiO2/HAp material calculated by the DRS measurement was 3.6 eV, while that of HAp pure was 5.3 eV and that of TiO2 pure was around 3.2 eV. The shift of the band gap energy of TiO2 in the range of 3.2–3.6 eV may be related to the shifts of Ti signals of XPS spectrum.

  5. The HSP90 binding mode of a radicicol-like E-oxime from docking, binding free energy estimations, and NMR 15N chemical shifts

    Science.gov (United States)

    Spichty, Martin; Taly, Antoine; Hagn, Franz; Kessler, Horst; Barluenga, Sofia; Winssinger, Nicolas; Karplus, Martin

    2009-01-01

    We determine the binding mode of a macrocyclic radicicol-like oxime to yeast HSP90 by combining computer simulations and experimental measurements. We sample the macrocyclic scaffold of the unbound ligand by parallel tempering simulations and dock the most populated conformations to yeast HSP90. Docking poses are then evaluated by the use of binding free energy estimations with the linear interaction energy method. Comparison of QM/MM-calculated NMR chemical shifts with experimental shift data for a selective subset of back-bone 15N provides an additional evaluation criteria. As a last test we check the binding modes against available structure-activity-relationships. We find that the most likely binding mode of the oxime to yeast HSP90 is very similar to the known structure of the radicicol-HSP90 complex. PMID:19482409

  6. Communication: Towards the binding energy and vibrational red shift of the simplest organic hydrogen bond: Harmonic constraints for methanol dimer

    Energy Technology Data Exchange (ETDEWEB)

    Heger, Matthias; Suhm, Martin A.; Mata, Ricardo A., E-mail: rmata@gwdg.de [Georg-August-Universität Göttingen, Institut für Physikalische Chemie, Tammannstr. 6, 37077 Göttingen (Germany)

    2014-09-14

    The discrepancy between experimental and harmonically predicted shifts of the OH stretching fundamental of methanol upon hydrogen bonding to a second methanol unit is too large to be blamed mostly on diagonal and off-diagonal anharmonicity corrections. It is shown that a decisive contribution comes from post-MP2 electron correlation effects, which appear not to be captured by any of the popular density functionals. We also identify that the major deficiency is in the description of the donor OH bond. Together with estimates for the electronic and harmonically zero-point corrected dimer binding energies, this work provides essential constraints for a quantitative description of this simple hydrogen bond. The spectroscopic dissociation energy is predicted to be larger than 18 kJ/mol and the harmonic OH-stretching fundamental shifts by about −121 cm{sup −1} upon dimerization, somewhat more than in the anharmonic experiment (−111 cm{sup −1})

  7. Thickness-Dependent Binding Energy Shift in Few-Layer MoS2 Grown by Chemical Vapor Deposition.

    Science.gov (United States)

    Lin, Yu-Kai; Chen, Ruei-San; Chou, Tsu-Chin; Lee, Yi-Hsin; Chen, Yang-Fang; Chen, Kuei-Hsien; Chen, Li-Chyong

    2016-08-31

    The thickness-dependent surface states of MoS2 thin films grown by the chemical vapor deposition process on the SiO2-Si substrates are investigated by X-ray photoelectron spectroscopy. Raman and high-resolution transmission electron microscopy suggest the thicknesses of MoS2 films to be ranging from 3 to 10 layers. Both the core levels and valence band edges of MoS2 shift downward ∼0.2 eV as the film thickness increases, which can be ascribed to the Fermi level variations resulting from the surface states and bulk defects. Grainy features observed from the atomic force microscopy topographies, and sulfur-vacancy-induced defect states illustrated at the valence band spectra imply the generation of surface states that causes the downward band bending at the n-type MoS2 surface. Bulk defects in thick MoS2 may also influence the Fermi level oppositely compared to the surface states. When Au contacts with our MoS2 thin films, the Fermi level downshifts and the binding energy reduces due to the hole-doping characteristics of Au and easy charge transfer from the surface defect sites of MoS2. The shift of the onset potentials in hydrogen evolution reaction and the evolution of charge-transfer resistances extracted from the impedance measurement also indicate the Fermi level varies with MoS2 film thickness. The tunable Fermi level and the high chemical stability make our MoS2 a potential catalyst. The observed thickness-dependent properties can also be applied to other transition-metal dichalcogenides (TMDs), and facilitates the development in the low-dimensional electronic devices and catalysts. PMID:27488185

  8. Thickness-Dependent Binding Energy Shift in Few-Layer MoS2 Grown by Chemical Vapor Deposition.

    Science.gov (United States)

    Lin, Yu-Kai; Chen, Ruei-San; Chou, Tsu-Chin; Lee, Yi-Hsin; Chen, Yang-Fang; Chen, Kuei-Hsien; Chen, Li-Chyong

    2016-08-31

    The thickness-dependent surface states of MoS2 thin films grown by the chemical vapor deposition process on the SiO2-Si substrates are investigated by X-ray photoelectron spectroscopy. Raman and high-resolution transmission electron microscopy suggest the thicknesses of MoS2 films to be ranging from 3 to 10 layers. Both the core levels and valence band edges of MoS2 shift downward ∼0.2 eV as the film thickness increases, which can be ascribed to the Fermi level variations resulting from the surface states and bulk defects. Grainy features observed from the atomic force microscopy topographies, and sulfur-vacancy-induced defect states illustrated at the valence band spectra imply the generation of surface states that causes the downward band bending at the n-type MoS2 surface. Bulk defects in thick MoS2 may also influence the Fermi level oppositely compared to the surface states. When Au contacts with our MoS2 thin films, the Fermi level downshifts and the binding energy reduces due to the hole-doping characteristics of Au and easy charge transfer from the surface defect sites of MoS2. The shift of the onset potentials in hydrogen evolution reaction and the evolution of charge-transfer resistances extracted from the impedance measurement also indicate the Fermi level varies with MoS2 film thickness. The tunable Fermi level and the high chemical stability make our MoS2 a potential catalyst. The observed thickness-dependent properties can also be applied to other transition-metal dichalcogenides (TMDs), and facilitates the development in the low-dimensional electronic devices and catalysts.

  9. Observation of core-level binding energy shifts between (100) surface and bulk atoms of epitaxial CuInSe2

    International Nuclear Information System (INIS)

    Core-level and valence band photoemission from semiconductors has been shown to exhibit binding energy differences between surface atoms and bulk atoms, thus allowing one to unambiguously distinguish between the two atomic positions. Quite clearly, surface atoms experience a potential different from the bulk due to the lower coordination number - a characteristic feature of any surface is the incomplete atomic coordination. Theoretical accounts of this phenomena are well documented in the literature for III-V and II-VI semiconductors. However, surface state energies corresponding to the equilibrium geometry of (100) and (111) surfaces of Cu-based ternary chalcopyrite semiconductors have not been calculated or experimental determined. These compounds are generating great interest for optoelectronic and photovoltaic applications, and are an isoelectronic analog of the II-VI binary compound semiconductors. Surface core-level binding energy shifts depend on the surface cohesive energies, and surface cohesive energies are related to surface structure. For ternary compound semiconductor surfaces, such as CuInSe2, one has the possibility of variations in surface stoichiometry. Applying standard thermodynamical calculations which consider the number of individual surface atoms and their respective chemical potentials should allow one to qualitatively determine the magnitude of surface core-level shifts and, consequently, surface state energies

  10. Observation of core-level binding energy shifts between (100) surface and bulk atoms of epitaxial CuInSe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, A.J. [Colorado School of Mines, Golden, CO (United States); Berry, G.; Rockett, A. [Univ. of Illinois, Urbana-Champaign, IL (United States)] [and others

    1997-04-01

    Core-level and valence band photoemission from semiconductors has been shown to exhibit binding energy differences between surface atoms and bulk atoms, thus allowing one to unambiguously distinguish between the two atomic positions. Quite clearly, surface atoms experience a potential different from the bulk due to the lower coordination number - a characteristic feature of any surface is the incomplete atomic coordination. Theoretical accounts of this phenomena are well documented in the literature for III-V and II-VI semiconductors. However, surface state energies corresponding to the equilibrium geometry of (100) and (111) surfaces of Cu-based ternary chalcopyrite semiconductors have not been calculated or experimental determined. These compounds are generating great interest for optoelectronic and photovoltaic applications, and are an isoelectronic analog of the II-VI binary compound semiconductors. Surface core-level binding energy shifts depend on the surface cohesive energies, and surface cohesive energies are related to surface structure. For ternary compound semiconductor surfaces, such as CuInSe{sub 2}, one has the possibility of variations in surface stoichiometry. Applying standard thermodynamical calculations which consider the number of individual surface atoms and their respective chemical potentials should allow one to qualitatively determine the magnitude of surface core-level shifts and, consequently, surface state energies.

  11. The electronic structure and grain boundary segregation by boron addition——A binding energy shifting criterion for the brittle-ductile fracture transition in Ni3Al

    Institute of Scientific and Technical Information of China (English)

    张云; 林栋梁

    1997-01-01

    The electronic structure and grain boundary segregation caused by boron addition to Ni3Al have been studied by X-ray photoelectron spectroscopy and Auger electron spectroscopy, respectively. The obtained results show that the Ni2p3/2 electron binding energy rises gradually in the sequence of pure Ni< Ni76Al24< Ni74Al26 < Ni25Al25, while it reduces monotonously with an increase in boron addition to Ni3Al. Besides, it is found that the gram boundary segregation of boron occurring in Ni3Al is a combined equilibrium and non-equilibrium type in nature. Based on the concept of the bonding environmental inhomogeneity, measured by the shift in Ni2p3/2 electron binding energy from the nickel atoms in the simple substance nickel to those in the intermetallic compound Ni3Al (ΔEB), being responsible for the brittle behavior of the alloy, a binding energy shifting criterion for the brittle-ductile fracture transition in Ni3Al is presented: when ΔEB>0, the brittle failure occurs in Ni3Al; when ΔEB<0, the ductile o

  12. Energy phase shift as mechanism for catalysis

    KAUST Repository

    Beke-Somfai, Tamás

    2012-05-01

    Catalysts are agents that by binding reactant molecules lower the energy barriers to chemical reaction. After reaction the catalyst is regenerated, its unbinding energy recruited from the environment, which is associated with an inevitable loss of energy. We show that combining several catalytic sites to become energetically and temporally phase-shifted relative to each other provides a possibility to sustain the overall reaction by internal \\'energy recycling\\', bypassing the need for thermal activation, and in principle allowing the system to work adiabatically. Using an analytical model for superimposed, phase-shifted potentials of F 1-ATP synthase provides a description integrating main characteristics of this rotary enzyme complex. © 2012 Elsevier B.V. All rights reserved.

  13. THEORETICAL-ANALYSIS OF THE O(1S) BINDING-ENERGY SHIFTS IN ALKALINE-EARTH OXIDES - CHEMICAL OR ELECTROSTATIC CONTRIBUTIONS

    NARCIS (Netherlands)

    PACCHIONI, G; BAGUS, PS

    1994-01-01

    We report results from ab initio cluster-model calculations on the O(1s) binding energy (BE) in the alkaline-earth oxides, MgO, CaO, SrO, and BaO; all these oxides have a cubic lattice structure. We have obtained values for both the initial- and final-state BE's. A simple point-charge model, where a

  14. Binding Energy and Enzymatic Catalysis.

    Science.gov (United States)

    Hansen, David E.; Raines, Ronald T.

    1990-01-01

    Discussed is the fundamental role that the favorable free energy of binding of the rate-determining transition state plays in catalysis. The principle that all of the catalytic factors discussed are realized by the use of this binding energy is reviewed. (CW)

  15. Exchange energy shifts under dense plasma conditions

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiangdong [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Xu Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Rosmej, F B [Universite de Provence et CNRS, UMR 6633 Centre St Jerome, PIIM, 13397 Marseille Cedex 20 (France)

    2006-08-28

    The variation of the energy interval between the intercombination line (1s2p({sup 3}P{sub 1}){yields}1s{sup 2}) and the resonance line (1s2p({sup 1}P{sub 1}){yields}1s{sup 2}) of He-like aluminium with plasma density and temperature is investigated. Since such energy interval is equivalent to the exchange energy of the state 1s2p({sup 3}P{sub 1}), we consider the dependence of this energy shift on the plasma environment. It was found that the shifts of exchange energy increase (decrease) with the increase of electron density (electron temperature), and the shifts of exchange energy become more sensitive to the electron density as the electron temperature decreases, i.e. in the strongly coupled plasma regime. An approximately linear relation is found between the shifts of exchange energy and the electron density. The results show that dense plasma effects are very important for the simulation of the spectral fine structure. The relative shifts between the intercombination (1s2p({sup 3}P{sub 1}){yields}1s{sup 2}) and the resonance line (1s2p({sup 1}P{sub 1}){yields}1s{sup 2}) are discussed for diagnostic applications.

  16. Skyrmions with low binding energies

    Directory of Open Access Journals (Sweden)

    Mike Gillard

    2015-06-01

    Full Text Available Nuclear binding energies are investigated in two variants of the Skyrme model: the first replaces the usual Skyrme term with a term that is sixth order in derivatives, and the second includes a potential that is quartic in the pion fields. Solitons in the first model are shown to deviate significantly from ansätze previously assumed in the literature. The binding energies obtained in both models are lower than those obtained from the standard Skyrme model, and those obtained in the second model are close to the experimental values.

  17. Skyrmions with low binding energies

    Energy Technology Data Exchange (ETDEWEB)

    Gillard, Mike, E-mail: m.n.gillard@leeds.ac.uk; Harland, Derek, E-mail: d.g.harland@leeds.ac.uk; Speight, Martin, E-mail: speight@maths.leeds.ac.uk

    2015-06-15

    Nuclear binding energies are investigated in two variants of the Skyrme model: the first replaces the usual Skyrme term with a term that is sixth order in derivatives, and the second includes a potential that is quartic in the pion fields. Solitons in the first model are shown to deviate significantly from ansätze previously assumed in the literature. The binding energies obtained in both models are lower than those obtained from the standard Skyrme model, and those obtained in the second model are close to the experimental values.

  18. Tight-binding theory of NMR shifts in topological insulators

    Science.gov (United States)

    Garate, Ion; Boutin, Samuel; Ramirez Ruiz, Jorge

    To date, most experiments in topological insulators have focused on probing the surface states of these materials and suppressing the often inevitable contribution from bulk states. However, the latter are of interest on their own and contain useful information that can be extracted with a local probe like nuclear magnetic resonance (NMR). Recently, 77Se NMR experiments on Bi2Se3 single crystals have reported unusual field-independent linewidths and short spin-echo decays. It is likely that an unexpectedly strong indirect internuclear coupling, characteristic of some inverted band structures, is the cause of these peculiar results. Motivated by this hypothesis, we report on a microscopic theory of NMR shifts and linewidths in Bi2Se3 and Bi2Te3. Our theory provides quantitative estimates for the Knight shift, the orbital shift, the Ruderman-Kittel-Kasuya-Yoshida coupling and the Bloembergen-Rowland coupling. We will compare our findings with the available experimental data Funded by the National Science and Engineering Research Council of Canada, Fonds de Recherche Québécois Nature et Technologies, and Mitacs-Globalink.

  19. Negative Energy: From Lamb Shift to Entanglement

    CERN Document Server

    Bu, Shou-Liang

    2016-01-01

    "Negative energy" has been one of the most enduring puzzles in quantum theory, whereas the present work reveals that it actually plays a central role in clarifying various controversies of quantum theory. The basic idea is contained in a hypothesis on negative energy, and it is shown that the idea: (1)is compatible with both relativistic quantum mechanics and known experimental results; (2)helps to clarify the essence of matter waves, and therefore better understand the reality of the wave function, the so-called 'wave-packet reduction' occurring in quantum measurement, and the ghost like correlations between entangled systems; (3)is helpful for distinguishing the vacuum from the ground state of the quantized field, and may supply a possible way for removing the deep-rooted infinities in quantum field theory. The vacuum energy density of the electromagnetic field is calculated here as an example. By employing the same idea, the Lamb-Shift is recalculated in a different way from conventional renormalization me...

  20. Gravitational Binding Energy in Charged Cylindrical Symmetry

    CERN Document Server

    Sharif, M

    2014-01-01

    We consider static cylindrically symmetric charged gravitating object with perfect fluid and investigate the gravitational binding energy. It is found that only the localized part of the mass function provides the gravitational binding energy, whereas the non-localized part generated by the electric coupling does not contribute for such energy.

  1. Quantum dot-antibody and amputator conjugates shift fluorescence upon binding bacteria

    International Nuclear Information System (INIS)

    CdSe/ZnS quantum dots (QDs) exhibited fluorescence emission blue shifts when conjugated to antibodies or DNA aptamers that are bound to bacteria. The intensity of the shifted emission peak increased with the number of bound bacteria. Curiously, the emission was consistently shifted to approximately 440-460 nm, which is distinctly different from the major component of the natural fluorescence spectrum of these QDs. This minor emission peak can grow upon conjugation to antibodies or aptamers and subsequent binding to bacterial cell surfaces. We hypothesize that the wavelength shift is due to changes in the chemical environment of the QD conjugates when they encounter the bacterial surface and may be due to physical deformation of the QD that changes the quantum confinement state. Regardless of the mechanism, these remarkable emission wavelength shifts of greater than 140 nm in some cases strongly suggest new applications for QD-receptor conjugates

  2. Pauli exclusion operator and binding energy of nuclear matter

    OpenAIRE

    Schiller, E.; Müther, H; Czerski, P.

    1998-01-01

    Brueckner-Hartree-Fock calculations are performed for nuclear matter with an exact treatment of the Pauli exclusion operator in the Bethe-Goldstone equation. The differences in the calculated binding energy, compared to the angle-average approximation, which is commonly used, are non-negligible. These difference exhibits a specific density dependence, which shifts the calculated saturation point towards smaller densities. This effect is observed for various versions of modern models for the N...

  3. Pauli Exclusion Operator and Binding Energy of Nuclear Matter

    International Nuclear Information System (INIS)

    Full text: Brueckner-Hartree-Fock calculations are performed for nuclear matter with an exact treatment of the Pauli exclusion operator in the Bethe-Goldstone equation. The differences in the calculated binding energy, compared to the angle-average approximation, which is commonly used, are non-negligible. These difference exhibits a specific density dependence, which shifts the calculated saturation point towards smaller densities. This effect is observed for various versions of modern models for the NN interaction. (author)

  4. Grey Literature in Energy: A Shifting Paradigm

    OpenAIRE

    Cutler, Deborah E. (OSTI-DOE); GreyNet, Grey Literature Network Service

    2000-01-01

    Grey literature has long been a focus area for both the U.S. Department of Energy's Office of Scientific and Technical Information (OSTI) and the multinational information exchange agreements in which OSTI participates. The International Energy Agency's Energy Technology Data Exchange (ETDE) and the International Atomic Energy Agency's International Nuclear Information System (INIS), along with their member countries, are OSTI's principal global partners in the exchange of energy-related grey...

  5. Energy efficiency improvement by gear shifting optimization

    Directory of Open Access Journals (Sweden)

    Blagojevic Ivan A.

    2013-01-01

    Full Text Available Many studies have proved that elements of driver’s behavior related to gear selection have considerable influence on the fuel consumption. Optimal gear shifting is a complex task, especially for inexperienced drivers. This paper presents an implemented idea for gear shifting optimization with the aim of fuel consumption minimization with more efficient engine working regimes. Optimized gear shifting enables the best possible relation between vehicle motion regimes and engine working regimes. New theoretical-experimental approach has been developed using On-Board Diagnostic technology which so far has not been used for this purpose. The matrix of driving modes according to which tests were performed is obtained and special data acquisition system and analysis process have been developed. Functional relations between experimental test modes and adequate engine working parameters have been obtained and all necessary operations have been conducted to enable their use as inputs for the designed algorithm. The created Model has been tested in real exploitation conditions on passenger car with Otto fuel injection engine and On-Board Diagnostic connection without any changes on it. The conducted tests have shown that the presented Model has significantly positive effects on fuel consumption which is an important ecological aspect. Further development and testing of the Model allows implementation in wide range of motor vehicles with various types of internal combustion engines.

  6. Predicting binding free energies in solution

    CERN Document Server

    Jensen, Jan H

    2015-01-01

    Recent predictions of absolute binding free energies of host-guest complexes in aqueous solution using electronic structure theory have been encouraging for some systems, while other systems remain problematic for others. In paper I summarize some of the many factors that could easily contribute 1-3 kcal/mol errors at 298 K: three-body dispersion effects, molecular symmetry, anharmonicity, spurious imaginary frequencies, insufficient conformational sampling, wrong or changing ionization states, errors in the solvation free energy of ions, and explicit solvent (and ion) effects that are not well-represented by continuum models. While the paper is primarily a synthesis of previously published work there are two new results: the adaptation of Legendre transformed free energies to electronic structure theory and a use of water clusters that maximizes error cancellation in binding free energies computed using explicit solvent molecules. While I focus on binding free energies in aqueous solution the approach also a...

  7. Binding energies of hypernuclei and hypernuclear interactions

    Energy Technology Data Exchange (ETDEWEB)

    Bodmer, A.R. [Argonne National Lab., IL (United States)]|[Univ. of Illinois, Chicago, IL (United States). Dept. of Physics; Murali, S.; Usmani, Q.N. [Jamia Millia Islamia, New Delhi (India). Dept. of Physics

    1996-05-01

    In part 1 the effect of nuclear core dynamics on the binding energies of {Lambda} hypernuclei is discussed in the framework of variational correlated wave functions. In particular, the authors discuss a new rearrangement energy contribution and its effect on the core polarization. In part 2 they consider the interpretation of the {Lambda} single-particle energy in terms of basic {Lambda}-nuclear interactions using a local density approximation based on a Fermi hypernetted chain calculation of the A binding to nuclear matter. To account for the data strongly repulsive 3-body {Lambda}NN forces are required. Also in this framework they discuss core polarization for medium and heavier hypernuclei.

  8. Energy-shifting formulae yield reliable reaction and capture probabilities

    International Nuclear Information System (INIS)

    Predictions of energy-shifting formulae for partial reaction and capture probabilities are compared with coupled channels calculations. The quality of the agreement notably improves with increasing mass of the system and/or decreasing mass asymmetry in the heavy-ion collision. The formulae are reliable and useful for circumventing impracticable reaction calculations at low energies

  9. Binding Energy and Equilibrium of Compact Objects

    Directory of Open Access Journals (Sweden)

    Germano M.

    2014-04-01

    Full Text Available The theoretical analysis of the existence of a limit mass for compact astronomic ob- jects requires the solution of the Einstein’s equations of g eneral relativity together with an appropriate equation of state. Analytical solutions exi st in some special cases like the spherically symmetric static object without energy sou rces that is here considered. Solutions, i.e. the spacetime metrics, can have a singular m athematical form (the so called Schwarzschild metric due to Hilbert or a nonsingula r form (original work of Schwarzschild. The former predicts a limit mass and, conse quently, the existence of black holes above this limit. Here it is shown that, the origi nal Schwarzschild met- ric permits compact objects, without mass limit, having rea sonable values for central density and pressure. The lack of a limit mass is also demonst rated analytically just imposing reasonable conditions on the energy-matter densi ty, of positivity and decreas- ing with radius. Finally the ratio between proper mass and to tal mass tends to 2 for high values of mass so that the binding energy reaches the lim it m (total mass seen by a distant observer. As it is known the negative binding energ y reduces the gravitational mass of the object; the limit of m for the binding energy provides a mechanism for stable equilibrium of any amount of mass to contrast the gravitatio nal collapse.

  10. Global energy shifts: Future possibilities in historical perspective

    Science.gov (United States)

    Podobnik, Bruce Michael

    2000-11-01

    This study adopts a macro-comparative, world-systems perspective in order to shed light on the dynamics that led to a global shift away from primary reliance on coal and towards over-reliance on petroleum. It is argued that the interaction of three global dynamics, those of geopolitical rivalry, commercial competition, and social unrest, undermined the nineteenth-century international coal system and paved the way for the consolidation of an international petroleum system in the twentieth century. Specifically, the historical analysis presented in this dissertation shows that: (1) intervention by state agents was absolutely crucial in the early development and later expansion of the international petroleum system; (2) private coal companies attempted to prevent the consolidation of an oil-based energy system, but these older companies were out-competed by newer, multinational petroleum corporations; and (3) waves of labor unrest in established coal industries played a key role in prompting a relatively rapid shift away from coal and towards petroleum. Indeed, a key conclusion of this study is that pressures exerted by such social movements as labor unions, nationalist movements, and environmental coalitions have played as important a role in influencing energy trajectories as the more commonly-recognized actions of governmental and corporate actors. By examining contemporary patterns of state and private investments in a cluster of new energy technologies, as well as the growing influence of environmental regulations it is argued that global dynamics are beginning to favor a shift towards new, more environmentally sustainable energy technologies. The fuel cell is highlighted as one new energy technology that is poised to enter into widespread diffusion in the coming decades, though potentials for expansions in wind, solar, small-scale hydro-electric, and modern biomass systems are also examined. Although significant hurdles must be overcome, this study concludes by

  11. Pulse EPR-enabled interpretation of scarce pseudocontact shifts induced by lanthanide binding tags

    Energy Technology Data Exchange (ETDEWEB)

    Abdelkader, Elwy H.; Yao, Xuejun [Australian National University, Research School of Chemistry (Australia); Feintuch, Akiva [Weizmann Institute of Science, Department of Chemical Physics (Israel); Adams, Luke A.; Aurelio, Luigi; Graham, Bim [Monash University, Monash Institute of Pharmaceutical Sciences (Australia); Goldfarb, Daniella [Weizmann Institute of Science, Department of Chemical Physics (Israel); Otting, Gottfried, E-mail: gottfried.otting@anu.edu.au [Australian National University, Research School of Chemistry (Australia)

    2016-01-15

    Pseudocontact shifts (PCS) induced by tags loaded with paramagnetic lanthanide ions provide powerful long-range structure information, provided the location of the metal ion relative to the target protein is known. Usually, the metal position is determined by fitting the magnetic susceptibility anisotropy (Δχ) tensor to the 3D structure of the protein in an 8-parameter fit, which requires a large set of PCSs to be reliable. In an alternative approach, we used multiple Gd{sup 3+}-Gd{sup 3+} distances measured by double electron–electron resonance (DEER) experiments to define the metal position, allowing Δχ-tensor determinations from more robust 5-parameter fits that can be performed with a relatively sparse set of PCSs. Using this approach with the 32 kDa E. coli aspartate/glutamate binding protein (DEBP), we demonstrate a structural transition between substrate-bound and substrate-free DEBP, supported by PCSs generated by C3-Tm{sup 3+} and C3-Tb{sup 3+} tags attached to a genetically encoded p-azidophenylalanine residue. The significance of small PCSs was magnified by considering the difference between the chemical shifts measured with Tb{sup 3+} and Tm{sup 3+} rather than involving a diamagnetic reference. The integrative sparse data approach developed in this work makes poorly soluble proteins of limited stability amenable to structural studies in solution, without having to rely on cysteine mutations for tag attachment.

  12. Parity Violating Energy Shifts and Berry Phases in Atoms, I

    OpenAIRE

    Bruss, D.; Gasenzer, T.; Nachtmann, O

    1998-01-01

    We present a study of parity (P) violating contributions to the eigenenergies of stationary systems containing atoms in spatially inhomogeneous external electric fields. In this context the subtle interplay of P-violation and time reversal (T) invariance plays an important role. If the entire field configuration is chosen to exhibit chirality the energies are in general shifted by pseudoscalar contributions which change sign under a planar reflection of the field. To calculate the effects we ...

  13. The Lamb Shift and Ultra High Energy Cosmic Rays

    CERN Document Server

    Xue, S S

    2002-01-01

    On the analogy with the Lamb shift, we study the vacuum effects that a proton interacts with virtual particles when it travels through the vacuum. We find that a moving proton is accelerated by gaining the zero-point energy from the vacuum (~10^{-5} eV/cm). Such an effect possibly accounts for the mysterious origin and spectrum of ultra high-energy cosmic ray events above 10^{20}eV, and explains the puzzle why the GZK cutoff is absent. The candidates of these events could be protons from early Universe.

  14. Systematic Calculations of Total Atomic Binding Energies

    International Nuclear Information System (INIS)

    We have calculated total atomic binding energies of 3- to 91-electron ions of all atoms with Z=3 to 118, in the Dirac-Fock model, for applications to atomic mass determination from highly-charged ions. In this process we have determined the ground-state configuration of many ions for which it was not known. We also provide total electronic correlation including Breit correlation for iso-electronic series of beryllium, neon, magnesium and argon, using the multiconfiguration Dirac-Fock approach.

  15. Isotope effect on the zero point energy shift upon condensation

    International Nuclear Information System (INIS)

    The various isotope-dependent and independent atomic and molecular properties that pertain to the isotopic difference between the zero point energy (ZPE) shifts upon condensation were derived. The theoretical development of the change of the ZPE associated with the internal molecular vibrations, due to the condensation of the gaseous molecules, is presented on the basis of Wolfsberg's second-order perturbation treatment of the isotope-dependent London dispersion forces between liquid molecules. The isotope effect on the ZPE shift is related to the difference between the sums of the integrated intensities of the infrared absorption bands of the two gaseous isotopic molecules. The effective atomic charges are also calculated from available experimental infrared intensity data. The effects of isotopic substitutions of carbon-13 for carbon-12 and/or deuterium for protium, in ethylene, methane, and the fluorinated methanes, CH3F, CH2F2, CHF3, and CF4, on the ZPE shift upon condensation are calculated. These results compare well with the Bigeleisen B-factors, which are experimentally obtained from vapor pressure measurements of the isotopic species. Each of the following molecular properties will tend to increase the isotopic difference between the ZPE shifts upon condensation: (1) large number of highly polar bonds, (2) high molecular weight, (3) non-polar (preferably) or massive molecule, (4) non-hydrogenous molecule, and (5) closely packed liquid molecules. These properties will result in stronger dispersion forces in the liquid phase between the lighter molecules than between the isotopically heavier molecules. 36 tables, 9 figures

  16. Isotope effect on the zero point energy shift upon condensation

    Energy Technology Data Exchange (ETDEWEB)

    Kornblum, Z.C.; Ishida, T.

    1977-07-01

    The various isotope-dependent and independent atomic and molecular properties that pertain to the isotopic difference between the zero point energy (ZPE) shifts upon condensation were derived. The theoretical development of the change of the ZPE associated with the internal molecular vibrations, due to the condensation of the gaseous molecules, is presented on the basis of Wolfsberg's second-order perturbation treatment of the isotope-dependent London dispersion forces between liquid molecules. The isotope effect on the ZPE shift is related to the difference between the sums of the integrated intensities of the infrared absorption bands of the two gaseous isotopic molecules. The effective atomic charges are also calculated from available experimental infrared intensity data. The effects of isotopic substitutions of carbon-13 for carbon-12 and/or deuterium for protium, in ethylene, methane, and the fluorinated methanes, CH/sub 3/F, CH/sub 2/F/sub 2/, CHF/sub 3/, and CF/sub 4/, on the ZPE shift upon condensation are calculated. These results compare well with the Bigeleisen B-factors, which are experimentally obtained from vapor pressure measurements of the isotopic species. Each of the following molecular properties will tend to increase the isotopic difference between the ZPE shifts upon condensation: (1) large number of highly polar bonds, (2) high molecular weight, (3) non-polar (preferably) or massive molecule, (4) non-hydrogenous molecule, and (5) closely packed liquid molecules. These properties will result in stronger dispersion forces in the liquid phase between the lighter molecules than between the isotopically heavier molecules. 36 tables, 9 figures.

  17. An atomic clockwork using phase dependent energy shifts

    CERN Document Server

    De Munshi, D; Mukherjee, M

    2011-01-01

    A frequency stabilized laser referenced to an unperturbed atomic two level system acts as the most accurate clock with femtosecond clock ticks. For any meaningful use, a Femtosecond Laser Frequency Comb (FLFC) is used to transfer the atomic clock accuracy to electronically countable nanosecond clock ticks. Here we propose an alternative clockwork based on the phenomenon that when an atomic system is slowly evolved in a cyclic path, the atomic energy levels gather some phase called the geometric phase. This geometric phase dependent energy shift has been used here to couple the two frequency regimes in a phase coherent manner. It has also been shown that such a technique can be implemented experimentally, bypassing the highly involved setup of a FLFC.

  18. Electron binding energies using perturbative delta-SCF method

    Science.gov (United States)

    Bhusal, Shusil; Baruah, Tunna; Zope, Rajendra

    The knowledge of fundamental and optical gaps is of significant importance for organic photovoltaics. The electron binding energies estimated from the Kohn-Sham eigenvalues are significantly underestimated. Here, we use our recently outlined perturbative delta-SCF approach to compute the electron binding energies of a number of aromatic organic molecules commonly used in organic photovoltaics. Further, the electron affinities are also computed for the C60, C70 and PCBM. The results show that the perturbative delta-SCF provide adequate description of valence electron binding energies. We also applied the method to compute the core binding energies and the core-valence excited states. While the method can successfully predict the core-valence excited states the results on the core-binding energies are mixed. The strategies for improvement of the core binding energies will be discussed.

  19. Relativistic Nuclear Energy Density Functionals: adjusting parameters to binding energies

    CERN Document Server

    Niksic, T; Ring, P

    2008-01-01

    We study a particular class of relativistic nuclear energy density functionals in which only nucleon degrees of freedom are explicitly used in the construction of effective interaction terms. Short-distance (high-momentum) correlations, as well as intermediate and long-range dynamics, are encoded in the medium (nucleon density) dependence of the strength functionals of an effective interaction Lagrangian. Guided by the density dependence of microscopic nucleon self-energies in nuclear matter, a phenomenological ansatz for the density-dependent coupling functionals is accurately determined in self-consistent mean-field calculations of binding energies of a large set of axially deformed nuclei. The relationship between the nuclear matter volume, surface and symmetry energies, and the corresponding predictions for nuclear masses is analyzed in detail. The resulting best-fit parametrization of the nuclear energy density functional is further tested in calculations of properties of spherical and deformed medium-he...

  20. Effect of Nuclear Binding Energy to K Factor

    Institute of Scientific and Technical Information of China (English)

    HOU Zhao-Yu; GUO Ai-Qiang

    2007-01-01

    We modify the square of virtual photon four-momentum by using nuclear binding energy formula,and calculate the effect of nuclear binding energy to K factor and Compton subprocess and annihilate subprocess in A-A collision Drell-Yan process.The outcome indicates that the effect of nuclear binding energy to K factor is obvious in little x region and it would disappear gradually as x increases.

  1. Experimental Binding Energies in Supramolecular Complexes.

    Science.gov (United States)

    Biedermann, Frank; Schneider, Hans-Jörg

    2016-05-11

    On the basis of many literature measurements, a critical overview is given on essential noncovalent interactions in synthetic supramolecular complexes, accompanied by analyses with selected proteins. The methods, which can be applied to derive binding increments for single noncovalent interactions, start with the evaluation of consistency and additivity with a sufficiently large number of different host-guest complexes by applying linear free energy relations. Other strategies involve the use of double mutant cycles, of molecular balances, of dynamic combinatorial libraries, and of crystal structures. Promises and limitations of these strategies are discussed. Most of the analyses stem from solution studies, but a few also from gas phase. The empirically derived interactions are then presented on the basis of selected complexes with respect to ion pairing, hydrogen bonding, electrostatic contributions, halogen bonding, π-π-stacking, dispersive forces, cation-π and anion-π interactions, and contributions from the hydrophobic effect. Cooperativity in host-guest complexes as well as in self-assembly, and entropy factors are briefly highlighted. Tables with typical values for single noncovalent free energies and polarity parameters are in the Supporting Information. PMID:27136957

  2. Asymptotic Energies and QED Shifts for Rydberg States of Helium

    Science.gov (United States)

    Drake, G.W.F.

    2007-01-01

    This paper reviews progress that has been made in obtaining essentially exact solutions to the nonrelativistic three-body problem for helium by a combination of variational and asymptotic expansion methods. The calculation of relativistic and quantum electrodynamic corrections by perturbation theory is discussed, and in particular, methods for the accurate calculation of the Bethe logarithm part of the electron self energy are presented. As an example, the results are applied to the calculation of isotope shifts for the short-lived 'halo' nucleus He-6 relative to He-4 in order to determine the nuclear charge radius of He-6 from high precision spectroscopic measurements carried out at the Argonne National Laboratory. The results demonstrate that the high precision that is now available from atomic theory is creating new opportunities to create novel measurement tools, and helium, along with hydrogen, can be regarded as a fundamental atomic system whose spectrum is well understood for all practical purposes.

  3. Extrapolations of nuclear binding energies from new linear mass relations

    DEFF Research Database (Denmark)

    Hove, D.; Jensen, A. S.; Riisager, K.

    2013-01-01

    We present a method to extrapolate nuclear binding energies from known values for neighboring nuclei. We select four specific mass relations constructed to eliminate smooth variation of the binding energy as function nucleon numbers. The fast odd-even variations are avoided by comparing nuclei...

  4. Binding-energy distribution and dephasing of localized biexcitons

    DEFF Research Database (Denmark)

    Langbein, Wolfgang Werner; Hvam, Jørn Märcher; Umlauff, M.;

    1997-01-01

    We report on the binding energy and dephasing of localized biexciton states in narrow ZnSe multiple quantum wells. The measured binding-energy distribution of the localized biexcitons shows a width of 2.2 meV centered at 8.5 meV, and is fairly independent of the exciton localization energy. In four......-wave mixing, the biexciton photon echo decays fast and nonexponentially. This behavior results from the inhomogeneous broadening of the biexciton binding energy, as we show by a comparison with an analytical model calculation. The fast decay is thus not related to a fast microscopic biexciton dephasing....

  5. Influence of binding energies of electrons on nuclear mass predictions

    Science.gov (United States)

    Tang, Jing; Niu, Zhong-Ming; Guo, Jian-You

    2016-07-01

    Nuclear mass contains a wealth of nuclear structure information, and has been widely employed to extract the nuclear effective interactions. The known nuclear mass is usually extracted from the experimental atomic mass by subtracting the masses of electrons and adding the binding energy of electrons in the atom. However, the binding energies of electrons are sometimes neglected in extracting the known nuclear masses. The influence of binding energies of electrons on nuclear mass predictions are carefully investigated in this work. If the binding energies of electrons are directly subtracted from the theoretical mass predictions, the rms deviations of nuclear mass predictions with respect to the known data are increased by about 200 keV for nuclei with Z, N ⩾ 8. Furthermore, by using the Coulomb energies between protons to absorb the binding energies of electrons, their influence on the rms deviations is significantly reduced to only about 10 keV for nuclei with Z, N ⩾ 8. However, the binding energies of electrons are still important for the heavy nuclei, about 150 keV for nuclei around Z = 100 and up to about 500 keV for nuclei around Z = 120. Therefore, it is necessary to consider the binding energies of electrons to reliably predict the masses of heavy nuclei at an accuracy of hundreds of keV. Supported by National Natural Science Foundation of China (11205004)

  6. HYPERSATELLITE AND SATELLITE ENERGY SHIFTS AND INTENSITY RATIOS

    OpenAIRE

    Horvat, V.; Ilakovac, K.; VeskoviĆ, M.; KauČiĆ, S.

    1987-01-01

    Measurements of the decay of xenon and silver atoms with double K-shell vacancies (vacant K shell) were performed using a pair of germanium detectors and a three-parameter pulse-height analyzer. In xenon Kα hypersatellite shift and relative intensities of K hypersatellite and K satellite transitions were obtained. In silver the same quantities and also Kβ hypersatellite shift, Kα and Kβ satellite shifts with L-spectator vacancy and Kβ satellite shift with M- and N- spectator vacancy were dete...

  7. Atomic Mass and Nuclear Binding Energy for Fe-52 (Iron)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume A `Nuclei with Z = 1 - 54' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Fe-52 (Iron, atomic number Z = 26, mass number A = 52).

  8. Atomic Mass and Nuclear Binding Energy for Sr-71 (Strontium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume A `Nuclei with Z = 1 - 54' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Sr-71 (Strontium, atomic number Z = 38, mass number A = 71).

  9. Energy shift estimation of demand response activation on domestic refrigerators – A field test study

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam; Gudmand-Høyer, Kristian; Marinelli, Mattia;

    2014-01-01

    This paper presents a method to estimate the amount of energy that can be shifted during demand response (DR) activation on domestic refrigerator. Though there are many methods for DR activation like load reduction, load shifting and onsite generation, the method under study is load shifting. Ele...

  10. Predicting accurate absolute binding energies in aqueous solution

    DEFF Research Database (Denmark)

    Jensen, Jan Halborg

    2015-01-01

    Recent predictions of absolute binding free energies of host-guest complexes in aqueous solution using electronic structure theory have been encouraging for some systems, while other systems remain problematic. In this paper I summarize some of the many factors that could easily contribute 1-3 kcal......-represented by continuum models. While I focus on binding free energies in aqueous solution the approach also applies (with minor adjustments) to any free energy difference such as conformational or reaction free energy differences or activation free energies in any solvent....

  11. Nuclear binding energies from a BPS Skyrme model

    OpenAIRE

    Adam, C.; Naya, C.; Sanchez-Guillen, J.(Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), Santiago de Compostela, E-15782, Spain); Wereszczynski, A.

    2013-01-01

    Recently, within the space of generalized Skyrme models, a BPS submodel was identified which reproduces some bulk properties of nuclear matter already on a classical level and, as such, constitutes a promising field theory candidate for the detailed and reliable description of nuclei and hadrons. Here we extend and further develop these investigations by applying the model to the calculation of nuclear binding energies. Concretely, we calculate these binding energies by including the classica...

  12. Energy shift estimation of demand response activation on domestic refrigerators – A field test study

    OpenAIRE

    Lakshmanan, Venkatachalam; Gudmand-Høyer, Kristian; Marinelli, Mattia; Kosek, Anna Magdalena; Nørgård, Per Bromand

    2014-01-01

    This paper presents a method to estimate the amount of energy that can be shifted during demand response (DR) activation on domestic refrigerator. Though there are many methods for DR activation like load reduction, load shifting and onsite generation, the method under study is load shifting. Electric heating and cooling equipment like refrigerators, water heaters and space heaters and coolers are preferred for such DR activation because of their energy storing capacity. Accurate estimation o...

  13. Energy shift due to anisotropic black body radiation

    CERN Document Server

    Flambaum, Victor V; Safronova, Marianna S

    2015-01-01

    In many applications a source of the black-body radiation (BBR) can be highly anisotropic. This leads to the BBR shift that depends on tensor polarizability and on the projection of the total angular momentum of ions and atoms in a trap. We derived formula for the anisotropic BBR shift and performed numerical calculations of this effect for Ca$^+$ and Yb$^+$ transitions of experimental interest. These ions used for a design of high-precision atomic clocks, fundamental physics tests such as search for the Lorentz invariance violation and space-time variation of the fundamental constants, and quantum information. Anisotropic BBR shift may be one of the major systematic effect in these experiments.

  14. Study on shift schedule saving energy of automatic transmission of ground vehicles

    Institute of Scientific and Technical Information of China (English)

    龚捷; 赵丁选; 陈鹰; 陈宁

    2004-01-01

    To improve ground vehicle efficiency,shift schedule energy saving was proposed for the ground vehicle automatic transmission by studying the function of the torque converter and transmission in the vehicular drivetrain.The shift schedule can keep the torque converter working in the high efficiency range under all the working conditions except in the low efficiency range on the left when the transmission worked at the lowest shift,and in the low efficiency range on the right when the transmission worked at the highest shift.The shift quality key factors were analysed.The automatic transmission's bench-test adopting this shift schedule was made on the automatic transmission's test-bed.The experimental results showed that the shift schedule was correct and that the shift quality was controllable.

  15. Study on shift schedule saving energy of automatic transmission of ground vehicles

    Institute of Scientific and Technical Information of China (English)

    龚捷; 赵丁选; 陈鹰; 陈宁

    2004-01-01

    To improve ground vehicle efficiency, shift schedule energy saving was proposed for the ground vehicle automatic transmission by studying the function of the torque converter and transmission in the vehicular drivetrain. The shift schedule can keep the torque converter working in the high efficiency range under all the working conditions except in the low efficiency range on the left when the transmission worked at the lowest shift, and in the low efficiency range on the right when the transmission worked at the highest shift. The shift quality key factors were analysed. The automatic trans-mission's bench-test adopting this shift schedule was made on the automatic transmission's test-bed. The experimental results showed that the shift schedule was correct and that the shift quality was controllable.

  16. Water–gas shift catalyst development for energy efficient applications

    NARCIS (Netherlands)

    Hakeem, A.A.

    2014-01-01

    The water–gas shift (WGS) is a reversible, moderately exothermic reaction (1) and is used for the production of hydrogen from CO rich gas streams (synthesis gas). CO + H2O ⇆ CO2 + H2 ΔH°= –41 kJ mol−1 (1) This research has focused on the catalyst

  17. Atomic Mass and Nuclear Binding Energy for Ra-226 (Radium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Ra-226 (Radium, atomic number Z = 88, mass number A = 226).

  18. Photon Binding Energy during Self-trapping and filaments' Self-Organisation

    Science.gov (United States)

    Dantu, Subbarao; Uma, R.; Goyal, Sanjeev

    2000-10-01

    Self-trapping profiles of laser beams in one space dimension and in cylindrical geometry are obtained for saturating-type nonlinearities computationally. The relavant nonlinear Shrodinger equations are solved adjusting for the nonlinear wavenumber shifts till self-trapping is achieved.Note that in one space dimension case the self-trapping condition is the same as for soliton formation. The modelling of the self-trapped beams is done using an approximate gaussian ansatz. Self-consistency then demands that the refractive index profile be approximated by a suitable parabolic profile in space corresponding to two nearby turning points being present simultaneously. The estimation of the location of the turning points is accomplished by using the scheme of approximation on the refractive index in momentum space as suggested by Subbarao et.al.(Phys.Plasmas vol.5, pp.3440-3450 (1998)). This scheme automatically also suggests the method to estimate the per photon binding energy in the self-trapped beam that indicates the strength of self-trapping.The photon binding energy vs. the laser beam intensity is the required photon binding energy curve.Being so similar to the nuclear binding energy curve in shape, it also goes on to suggest how to accomplish more stable self-trapped structures by the fusion or fission of self-trapped filaments thereby giving rise to a new form of self-organisation.

  19. Zero-Energy and Beyond: A Paradigm Shift in Assessment

    Directory of Open Access Journals (Sweden)

    Ronald Rovers

    2014-12-01

    Full Text Available The world is on the eve of major changes in the way energy and material are used, and the building and construction sector is at the forefront. One of the revolutionary changes is that for 0-energy houses and buildings. Many countries already have some projects established, and legislation is following, first requiring near 0-energy, but undoubtedly this will evolve into 0-energy as basic requirement. Buildings will generate all required energy from within their building lot, from incoming free and renewable energy sources: solar radiation and earth core heat mainly. In other words, there are no polluting or depleting issues anymore related to energy consumed to operate a building. This will change the whole approach in evaluation and optimization of the environmental performance of buildings: while the energy-driven measures for buildings become obsolete, it will be materials needed for this transition that have to become the main focus, as argued in this paper.

  20. Visualising the Global Shift in Energy Demand and Supply

    OpenAIRE

    Muhammad Isma'il

    2012-01-01

    The global energy demand depends on supplies from fossil fuels responsible for climate change. The supply of the fossil fuels required to meet the global energy demand depends on production from the available proved reserves of oil, coal and gas unevenly distributed around the world. On the other hand, the energy demand of a country is determined by its economic growth and population dynamics. The industrialised nations accounted for the rising demand in global primary energy. However, a glob...

  1. Economic assessment of energy storage for load shifting in Positive Energy Building

    DEFF Research Database (Denmark)

    Dumont, Olivier; Carmo, Carolina; Georges, Emeline;

    2016-01-01

    Net Zero Energy Buildings (NZEB) and Positive Energy Buildings (PEB) are gaining more and more interest. In this paper, the impact of the integration of a battery in a positive energy building is assessed in order to increase its self-consumption of electricity. Parametric studies are carried out...... by varying the building envelope characteristics, the power supply system, the climate, the lightning and appliances profiles, the roof tilt, the battery size and the electricity tariffs, leading to 3200 cases. The analysis is performed on an annual basis in terms of self-consumption rate, shifted energy...... and payback period. It is shown that the battery size leading to the minimum payback period within the input range, is comprised between 2.6 kWh and 6.2 kWh. The lowest payback periods, (~5.6 years), are reached with a well-insulated building envelope, a high lightning and appliance consumption, a low feed...

  2. Electromagnetic corrections to the hadronic phase shifts in low energy $\\pi^{+}p$ elastic scattering

    CERN Document Server

    Gashi, A; Oades, G C; Rasche, G; Woolcock, W S

    2001-01-01

    We calculate the s and p-wave electromagnetic corrections which must be subtracted from the nuclear phase shifts obtained from the analysis of low energy pi+p elastic scattering data, in order to obtain hadronic phase shifts. We compare our results with earlier calculations and estimate the uncertainties in the corrections.

  3. Binding Energy of Excitons in a Quantum Ring

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2008-01-01

    The binding energy of excitons confined to a quantum ring under the influence of perpendicular homogeneous magnetic field is calculated as a function of the ring radius. Calculations are made by using the method of exact diagonalization within the effective-mass approximation. The feature of binding energy of the ground state as a function of the ring radius for several values of the magnetic field has been revealed. The interesting feature of our study is that, in a quantum ring, the geometric structure of excitons may reveal transition.

  4. Shift to a low carbon society through energy systems design

    Institute of Scientific and Technical Information of China (English)

    Toshihiko; NAKATA; Mikhail; RODIONOV; Diego; SILVA; Joni; JUPESTA

    2010-01-01

    Concern about global warming calls for an advanced approach for designing an energy system to reduce carbon emissions as well as to secure energy security for each country.Conventional energy systems tend to introduce different technologies with high conversion efficiency,leading to a higher average efficiency.Advanced energy systems can be achieved not by an aggregate form of conversion technologies but by an innovative system design itself.The concept of LCS(low carbon society) is a unique approach having multi-dimensional considerations such as social,economic and environmental dimensions.The LCS aims at an extensive restructuring of worldwide energy supply/demand network system by not only replacing the conventional parts with the new ones,but also integrating all the necessary components and designing absolutely different energy networks.As a core tool for the LCS design,energy-economic models are applied to show feasible solutions in future with alternatives such as renewable resources,combined heat and power,and smart grid operations.Models can introduce changes in energy markets,technology learning in capacity,and penetration of innovative technologies,leading to an optimum system configuration under priority settings.The paper describes recent trials of energy models application related to waste-to-energy,clean coal,transportation and rural development.Although the modelling approach is still under investigation,the output clearly shows possible options having variety of technologies and linkages between supply and demand sides.Design of the LCS means an energy systems design with the modelling approach,which gives solution for complex systems,choices among technologies,technology feasibility,R&D targets,and what we need to start.

  5. Low energy scattering phase shifts for meson-baryon systems

    Science.gov (United States)

    Detmold, William; Nicholson, Amy N.

    2016-06-01

    In this work, we calculate meson-baryon scattering phase shifts in four channels using lattice QCD methods. From a set of calculations at four volumes, corresponding to spatial sizes of 2, 2.5, 3, and 4 fm, and a pion mass of mπ˜390 MeV , we determine the scattering lengths and effective ranges for these systems at the corresponding quark masses. We also perform the calculation at a lighter quark mass, mπ˜230 MeV , on the largest volume. Using these determinations, along with those in previous work, we perform a chiral extrapolation of the scattering lengths to the physical point after correcting for the effective range contributions using the multivolume calculations performed at mπ˜390 MeV .

  6. Resolving shifting patterns of muscle energy use in swimming fish.

    Directory of Open Access Journals (Sweden)

    Shannon P Gerry

    Full Text Available Muscle metabolism dominates the energy costs of locomotion. Although in vivo measures of muscle strain, activity and force can indicate mechanical function, similar muscle-level measures of energy use are challenging to obtain. Without this information locomotor systems are essentially a black box in terms of the distribution of metabolic energy. Although in situ measurements of muscle metabolism are not practical in multiple muscles, the rate of blood flow to skeletal muscle tissue can be used as a proxy for aerobic metabolism, allowing the cost of particular muscle functions to be estimated. Axial, undulatory swimming is one of the most common modes of vertebrate locomotion. In fish, segmented myotomal muscles are the primary power source, driving undulations of the body axis that transfer momentum to the water. Multiple fins and the associated fin muscles also contribute to thrust production, and stabilization and control of the swimming trajectory. We have used blood flow tracers in swimming rainbow trout (Oncorhynchus mykiss to estimate the regional distribution of energy use across the myotomal and fin muscle groups to reveal the functional distribution of metabolic energy use within a swimming animal for the first time. Energy use by the myotomal muscle increased with speed to meet thrust requirements, particularly in posterior myotomes where muscle power outputs are greatest. At low speeds, there was high fin muscle energy use, consistent with active stability control. As speed increased, and fins were adducted, overall fin muscle energy use declined, except in the caudal fin muscles where active fin stiffening is required to maintain power transfer to the wake. The present data were obtained under steady-state conditions which rarely apply in natural, physical environments. This approach also has potential to reveal the mechanical factors that underlie changes in locomotor cost associated with movement through unsteady flow regimes.

  7. The Binding Energy Parameter for Common Envelope Evolution

    CERN Document Server

    Wang, Cheng; Li, Xiang-Dong

    2016-01-01

    The binding energy parameter $\\lambda$ plays a vital role in common envelope evolution. Though it is well known that $\\lambda$ takes different values for stars with different masses and varies during stellar evolution, it has been erroneously adopted as a constant in most of the population synthesis calculations. We have systematically calculated the values of $\\lambda$ for stars of masses $1-60\\,M_{\\odot}$ by use of an updated stellar evolution code, taking into account contribution from both gravitational energy and internal energy to the binding energy of the envelope. We adopt the criterion for the core-envelope boundary advocated by \\citet{Ivanova2011}. A new kind of $\\lambda$ with the enthalpy prescription is also investigated. We present fitting formulae for the calculated values of various kinds of $\\lambda$, which can be used in future population synthesis studies.

  8. The binding energy parameter for common envelope evolution

    Science.gov (United States)

    Wang, Chen; Jia, Kun; Li, Xiang-Dong

    2016-08-01

    The binding energy parameter λ plays a vital role in common envelope evolution. Though it is well known that λ takes different values for stars with different masses and varies during stellar evolution, it has been erroneously adopted as a constant in most population synthesis calculations. We have systematically calculated the values of λ for stars of masses 1 – 60 M ⊙ by use of an updated stellar evolution code, taking into account the contribution from both gravitational energy and internal energy to the binding energy of the envelope. We adopt the criterion for the core-envelope boundary advocated by Ivanova. A new kind of λ with an enthalpy prescription is also investigated. We present fitting formulae for the calculated values of various kinds of λ, which can be used in future population synthesis studies.

  9. The Long-Run Forecasting of Energy Prices Using the Model of Shifting Trend

    OpenAIRE

    Stanislav Radchenko

    2005-01-01

    This paper constructs long-term forecasts of energy prices using a reduced form model of shifting trend developed by Pindyck (1999). A Gibbs sampling algorithm is developed to estimate models with a shifting trend line which are used to construct 10-period-ahead and 15-period ahead forecasts. An advantage of forecasts from this model is that they are not very influenced by the presence of large, long-lived increases and decreases in energy prices. The forecasts form shifting trends model are ...

  10. Binding energy and fine structure of the He- ion

    Institute of Scientific and Technical Information of China (English)

    ZHUO; Lin; ZHU; Jing-jing; GOU; Bing-cong

    2007-01-01

    The variational method using a multiconfiguration wavefunction is carried out on the core-excited state 1s2s2p 4P0 for helium negative ion, including mass polarization and relativistic corrections. Binding energy and fine structure are reported. The results are compared with other theoretical and experimental date in the literature.

  11. Binding energy and stability of heavy and superheavy nuclei

    OpenAIRE

    Kolesnikov, N.N.

    2012-01-01

    Three different ways for description of binding energy of superheavy nuclei are discussed. First, one can consider superheavy nuclei as a part of a whole system of nuclei for which a global mass formula is found. Another way is the detailed local description of energy of superheavy nuclei taking into account the effects of shells and subshells. The third way of description, applied for nuclei in the region limited by principal magic numbers, is attached to the beta-stability line.

  12. Alternate Energy Sources for Thermalplastic Binding Agent Consolidation

    Energy Technology Data Exchange (ETDEWEB)

    Frame, B.J.

    1999-01-01

    A study was conducted to investigate microwave and electron beam technologies as alternate energy sources to consolidate fiber coated with a thermoplastic binding agent into preforms for composite molding applications. Bench experiments showed that both microwave and electron beam energy can produce heat sufficient to melt and consolidate a thermoplastic binding agent applied to fiberglass mat, and several two- and three-dimensional fiberglass preforms were produced with each method. In both cases, it is postulated that the heating was accomplished by the effective interaction of the microwave or electron beam energy with the combination of the mat preform and the tooling used to shape the preform. Both methods contrast with conventional thermal energy applied via infrared heaters or from a heated tool in which the heat to melt the thermoplastic binding agent must diffuse over time from the outer surface of the preform toward its center under a thermal gradient. For these reasons, the microwave and electron beam energy techniques have the potential to rapidly consolidate thick fiber preforms more efficiently than the thermal process. With further development, both technologies have the potential to make preform production more cost effective by decreasing cycle time in the preform tool, reducing energy costs, and by enabling the use of less expensive tooling materials. Descriptions of the microwave and electron beam consolidation experiments and a summary of the results are presented in this report.

  13. Extremal energy shifts of radiation from a ring near a rotating black hole

    CERN Document Server

    Karas, Vladimir

    2010-01-01

    Radiation from a narrow circular ring shows a characteristic double-horn profile dominated by photons having energy around the maximum or minimum of the allowed range, i.e. near the extremal values of the energy shift. The energy span of a spectral line is a function of the ring radius, black hole spin, and observer's view angle. We describe a useful approach to calculate the extremal energy shifts in the regime of strong gravity. Then we consider an accretion disk consisting of a number of separate nested annuli in the equatorial plane of Kerr black hole, above the innermost stable circular orbit (ISCO). We suggest that the radial structure of the disk emission could be reconstructed using the extremal energy shifts of the individual rings deduced from the broad wings of a relativistic spectral line.

  14. Identification of tissue-specific DNA-protein binding sites by means of two-dimensional electrophoretic mobility shift assay display.

    Science.gov (United States)

    Chernov, Igor P; Timchenko, Kira A; Akopov, Sergey B; Nikolaev, Lev G; Sverdlov, Eugene D

    2007-05-01

    We developed a technique of differential electrophoretic mobility shift assay (EMSA) display allowing identification of tissue-specific protein-binding sites within long genomic sequences. Using this approach, we identified 10 cell type-specific protein-binding sites (protein target sites [PTSs]) within a 137-kb human chromosome 19 region. In general, tissue-specific binding of proteins from different nuclear extracts by individual PTSs did not follow the all-or-nothing principle. Most often, PTS-protein complexes were formed in all cases, but they were different for different nuclear extracts used. PMID:17359930

  15. Core level binding energies of functionalized and defective graphene.

    Science.gov (United States)

    Susi, Toma; Kaukonen, Markus; Havu, Paula; Ljungberg, Mathias P; Ayala, Paola; Kauppinen, Esko I

    2014-01-01

    X-ray photoelectron spectroscopy (XPS) is a widely used tool for studying the chemical composition of materials and it is a standard technique in surface science and technology. XPS is particularly useful for characterizing nanostructures such as carbon nanomaterials due to their reduced dimensionality. In order to assign the measured binding energies to specific bonding environments, reference energy values need to be known. Experimental measurements of the core level signals of the elements present in novel materials such as graphene have often been compared to values measured for molecules, or calculated for finite clusters. Here we have calculated core level binding energies for variously functionalized or defected graphene by delta Kohn-Sham total energy differences in the real-space grid-based projector-augmented wave density functional theory code (GPAW). To accurately model extended systems, we applied periodic boundary conditions in large unit cells to avoid computational artifacts. In select cases, we compared the results to all-electron calculations using an ab initio molecular simulations (FHI-aims) code. We calculated the carbon and oxygen 1s core level binding energies for oxygen and hydrogen functionalities such as graphane-like hydrogenation, and epoxide, hydroxide and carboxylic functional groups. In all cases, we considered binding energy contributions arising from carbon atoms up to the third nearest neighbor from the functional group, and plotted C 1s line shapes by using experimentally realistic broadenings. Furthermore, we simulated the simplest atomic defects, namely single and double vacancies and the Stone-Thrower-Wales defect. Finally, we studied modifications of a reactive single vacancy with O and H functionalities, and compared the calculated values to data found in the literature.

  16. Computing dispersive, polarizable, and electrostatic shifts of excitation energy in supramolecular systems: PTCDI crystal.

    Science.gov (United States)

    Megow, Jörg

    2016-09-01

    The gas-to-crystal-shift denotes the shift of electronic excitation energies, i.e., the difference between ground and excited state energies, for a molecule transferred from the gas to the bulk phase. The contributions to the gas-to-crystal-shift comprise electrostatic as well as inductive polarization and dispersive energy shifts of the molecular excitation energies due to interaction with environmental molecules. For the example of 3,4,9,10-perylene-tetracarboxylic-diimide (PTCDI) bulk, the contributions to the gas-to-crystal shift are investigated. In the present work, electrostatic interaction is calculated via Coulomb interaction of partial charges while inductive and dispersive interactions are obtained using respective sum over states expressions. The coupling of higher transition densities for the first 4500 excited states of PTCDI was computed using transition partial charges based on an atomistic model of PTCDI bulk obtained from molecular dynamics simulations. As a result it is concluded that for the investigated model system of a PTCDI crystal, the gas to crystal shift is dominated by dispersive interaction. PMID:27608991

  17. Dark Energy, Paradigm Shifts, and the Role of Evidence

    CERN Document Server

    Lahav, Ofer

    2014-01-01

    We comment on cases in the history of Astronomy, which may shed some light on the current established but enigmatic concordance model of Cosmology. Should the model be understood by adding new entities such as Dark Matter and Dark Energy, or by modifying the underlying theory? For example, the prediction and discovery of planet Neptune can be regarded as analogous to finding a dark component; while explaining the anomalous perihelion precession of Mercury by General Relativity can be taken as analogous to the possibility that modified gravity is an alternative to dark components of the universe. In this paper, we revise this analogy coming from the history of astronomy with an eye to illustrating some of the similarities and differences between the two cases.

  18. The long-run forecasting of energy prices using the model of shifting trend

    Energy Technology Data Exchange (ETDEWEB)

    Radchenko, Stanislav

    2005-12-15

    Developing models for accurate long-term energy price forecasting is an important problem because these forecasts should be useful in determining both supply and demand of energy. On the supply side, long-term forecasts determine investment decisions of energy-related companies. On the demand side, investments in physical capital and durable goods depend on price forecasts of a particular energy type. Forecasting long-run rend movements in energy prices is very important on the macroeconomic level for several developing countries because energy prices have large impacts on their real output, the balance of payments, fiscal policy, etc. Pindyck (1999) argues that the dynamics of real energy prices is mean-reverting to trend lines with slopes and levels that are shifting unpredictably over time. The hypothesis of shifting long-term trend lines was statistically tested by Benard et al. (2004). The authors find statistically significant instabilities for coal and natural gas prices. I continue the research of energy prices in the framework of continuously shifting levels and slopes of trend lines started by Pindyck (1999). The examined model offers both parsimonious approach and perspective on the developments in energy markets. Using the model of depletable resource production, Pindyck (1999) argued that the forecast of energy prices in the model is based on the long-run total marginal cost. Because the model of a shifting trend is based on the competitive behavior, one may examine deviations of oil producers from the competitive behavior by studying the difference between actual prices and long-term forecasts. To construct the long-run forecasts (10-year-ahead and 15-year-ahead) of energy prices, I modify the univariate shifting trends model of Pindyck (1999). I relax some assumptions on model parameters, the assumption of white noise error term, and propose a new Bayesian approach utilizing a Gibbs sampling algorithm to estimate the model with autocorrelation. To

  19. Electromagnetic Corrections to the Hadronic Phase Shifts in Low-Energy $\\pi^{+}p$ Elastic Scattering

    CERN Document Server

    Gashi, A; Oades, G C; Rasche, G; Woolcock, W S

    1999-01-01

    We calculate for the s-, p(1/2)- and p(3/2)-waves the electromagnetic corrections which must be subtracted from the nuclear phase shifts obtained from the analysis of low energy pi+ p elastic scattering data, in order to obtain hadronic phase shifts. The calculation uses relativised Schroedinger equations containing the sum of an electromagnetic potential and an effective hadronic potential. We compare our results with those of previous calculations and qualitatively estimate the uncertainties in the corrections.

  20. Impurity binding energy for -doped quantum well structures

    Indian Academy of Sciences (India)

    V Tulupenko; C A Duque; R Demediuk; O Fomina; V Akimov; V Belykh; T Dmitrichenko; V Poroshin

    2014-10-01

    The binding energy of an impurity delta layer situated either in the centre or at the edge of a quantum well (QW) is theoretically considered for the example of -type Si0.8Ge0.2/Si/Si0.8Ge0.2 QW doped with phosphorus. Calculations are made for the case of not so big impurity concentrations, when impurity bands are not yet formed and it is still possible to treat impurity as isolated ones. It is shown on the base of self-consistent solution of Schrödinger, Poisson and electro-neutrality equations that impurity binding energy is dependent on the degree of impurity ionization and the most noticeably for the case of edge-doped QWs.

  1. Application of Henry's Law for Binding Energies of Adsorbed Hydrogen

    Science.gov (United States)

    Gillespie, Andrew; Dohnke, Elmar; Stalla, David; Sweany, Mark; Pfeifer, Peter

    2015-03-01

    The method of isosteres is the simplest method used to calculate the differential enthalpy of adsorption. However, it is incredibly sensitive to the choice of model and respective fitting parameters. For a set of isotherms measured on a specific sample, most models converge upon a similar value at high coverage, but are inconsistent in the low pressure regime. In this talk, we investigate the application of various models for localized and mobile adsorption at low pressures in order to obtain binding energy of hydrogen to the adsorbent surface. Henry's Law analysis of the Langmuir Model of adsorption yield binding energies in excellent agreement with those obtained from the Clausius Clapeyron relation. Work supported by DOE-EERE, Award No. DE-FG36-08GO18142.

  2. Improvement in a phenomenological formula for ground state binding energies

    CERN Document Server

    Gangopadhyay, G

    2016-01-01

    The phenomenological formula for ground state binding energy derived earlier (International Journal of Modern Physics E {\\bf 20} (2011) 179) has been modified. The parameters have been obtained by fitting the latest available tabulation of experimental values. The major modifications include a new term for pairing and introduction of a new neutron magic number at $N=160$. The new formula reduced the root mean square deviation to 363 keV, a substantial improvement over the previous version of the formula.

  3. Nuclear binding energy using semi empirical mass formula

    Science.gov (United States)

    Ankita, Suthar, B.

    2016-05-01

    In the present communication, semi empirical mass formula using the liquid drop model has been presented. Nuclear binding energies are calculated using semi empirical mass formula with various constants given by different researchers. We also compare these calculated values with experimental data and comparative study for finding suitable constants is added using the error plot. The study is extended to find the more suitable constant to reduce the error.

  4. Single particle spectrum and binding energy of nuclear matter

    OpenAIRE

    Baldo, M; Fiasconaro, A.

    2000-01-01

    In non-relativistic Brueckner calculations of nuclear matter, the self-consistent single particle potential is strongly momentum dependent. To simplify the calculations, a parabolic approximation is often used in the literature. The variation in the binding energy value introduced by the parabolic approximation is quantitatively analyzed in detail. It is found that the approximation can introduce an uncertainty of 1-2 MeV near the saturation density.

  5. Binding energy of the $X(3872)$ at unphysical pion masses

    CERN Document Server

    Baru, V; Filin, A A; Gegelia, J; Nefediev, A V

    2015-01-01

    Chiral extrapolation of the $X(3872)$ binding energy is investigated using the modified Weinberg formulation of chiral effective field theory for the $D \\bar{D}^*$ scattering. Given its explicit renormalisability, this approach is particularly useful to explore the interplay of the long- and short-range $D \\bar{D}^*$ forces in the $X(3872)$ from studying the light-quark (pion) mass dependence of its binding energy. In particular, the parameter-free leading-order calculation shows that the $X$-pole disappears for unphysical large pion masses. On the other hand, without contradicting the naive dimensional analysis, the higher-order pion-mass-dependent contact interaction can change the slope of the binding energy at the physical point yielding the opposite scenario of a stronger bound $X$ at pion masses larger than its physical value. An important role of the pion dynamics and of the 3-body $D\\bar{D}\\pi$ effects for chiral extrapolations of the $X$-pole is emphasised. The results of the present study should be ...

  6. Sectoral shift in industrial natural gas demand: A comparison with other energy types

    International Nuclear Information System (INIS)

    It has been recognized in a variety of studies that energy demand by industry has been effected not only by the changing energy intensity of the various sectors of industry, but also by the composition of industrial sector. A previous study group of the Energy Modeling Forum (EMF-8) found that sectoral shift, i.e., the relative decline in the energy intensive sectors of industry, has contributed at least one third of the decline in aggregate manufacturing energy intensity since the early 1970s. The specific types of energy use may also be important, however. For example, the effect of shifts in production by electricity intensive sectors has been shown to be somewhat different than that for fossil fuel

  7. Precise determination of neutron binding energy of 64Cu

    Science.gov (United States)

    Telezhnikov, S. A.; Granja, C.; Honzatko, J.; Pospisil, S.; Tomandl, I.

    2016-05-01

    The neutron binding energy in 64Cu has been accurately measured in thermal neutron capture. A composite target of natural Cu and NaCl was used on a high flux neutron beam using a large measuring time. The γ-ray spectrum emitted in the ( n, γ) reaction was measured with a HPGe detector in large statistics (up to 106 events per channel). Intrinsic limitations of HPGe detectors, which restrict the accuracy of energy calibration, were determined. The value B n of 64Cu was determined as 7915.867(24) keV.

  8. Ab initio surface core-level shifts and surface segregation energies

    DEFF Research Database (Denmark)

    Aldén, Magnus; Skriver, Hans Lomholt; Johansson, Börje

    1993-01-01

    We have calculated the surface core-level energy shifts of the 4d and 5d transition metals by means of local-density theory and a Green’s-function technique based on the linear muffin-tin orbitals method. Final-state effects are included by treating the core-ionized atom as an impurity located...... in the bulk and at the surface, respectively. It is shown that the study of surface core-level shifts provides an ideal tool for an accurate determination of the surface segregation energy of a substitutional (Z+1) impurity in a Z metal host (Z denotes atomic number)....

  9. Binding Energy Calculations for Novel Ternary Ionic Lattices

    Science.gov (United States)

    Rodríguez-Mijangos, Ricardo; Vazquez-Polo, Gustavo

    2002-03-01

    Theoretical calculations for the binding energy between metalic ions and negative ions on a novel ternary ionic lattice is carried out for several solid solutions prepared with different concentrations and characterized recently (1). The ternary lattices that reach a good miscibility are: KCl(x)KBr(y)RbCl(z) in three different concentrations: (x=y=z=0.33), (x=0.5, y=0.25, z=0.25) and (x=0.33, y=0.07, z=0.60). The binding energy for these novel structures is calculated from the lattice constants obtained by X ray diffractometry analysis performed on the samples and the Vegard law (2). For the repulsive force exponent m, an average of the m values was considered. The energy values obtained by the Born´expression are compared with corresponding energy values from the lattice with more complex expressions, such as the Born Mayer, Born-Van der Walls. There is a good aggreement between all these calculations. (1)R. R. Mijangos, A. Cordero-Borboa, E. Alvarez, M. Cervantes, Physics Letters A 282 (2001) 195-200. (2) G. Vazquez-Polo, R. R. Mijangos et al. Revista Mexicana de Fisica, 47, Diciembre 2001. In Press.

  10. Optimum community energy storage system for PV energy time-shift

    International Nuclear Information System (INIS)

    Highlights: • The performance and economic benefits of Pb-acid and Li-ion batteries are compared. • The business case during the decarbonisation pathway is assessed. • The aggregation from a community approach reduced the levelised cost by 37% by 2020. • For a forecast price of 16.3 p/kW h Li-ion battery cost must be less than 275 £/kW h. • A 10% subsidy will be needed for Li-ion batteries to achieve the 2020 forecast. - Abstract: A novel method has been designed to obtain the optimum community energy storage (CES) systems for end user applications. The method evaluates the optimum performance (including the round trip efficiency and annual discharge), levelised cost (LCOES), the internal rate of return and the levelised value of suitable energy storage technologies. A complimentary methodology was developed including three reference years (2012, 2020 and zero carbon year) to show the evolution of the business case during the low carbon transition. The method follows a community approach and the optimum CES system was calculated as a function of the size of the community. In this work, this method was put in practice with lead-acid (PbA) and lithium-ion battery (Li-ion) technologies when performing PV energy time-shift using real demand data from a single home to a 100-home community. The community approach reduced the LCOES down to 0.30 £/kW h and 0.11 £/kW h in 2020 and the zero carbon year respectively. These values meant a cost reduction by 37% and 66% regarding a single home. Results demonstrated that PbA batteries needs from 1.5 to 2.5 times more capacity than Li-ion chemistry to reduce the LCOES, the worst case scenario being for the smallest communities, because the more spiky demand profile required proportionately larger PbA battery capacities

  11. Ligand induced stabilization of the melting temperature of the HSV-1 single-strand DNA binding protein using the thermal shift assay

    OpenAIRE

    Rupesh, Kanchi Ravi; Smith, Aaron; Boehmer, Paul E.

    2014-01-01

    We have adapted the thermal shift assay to measure the ligand binding properties of the herpes simplex virus-1 single-strand DNA binding protein, ICP8. By measuring SYPRO Orange fluorescence in microtiter plates using a fluorescence-enabled thermal cycler, we have quantified the effects of oligonucleotide ligands on the melting temperature of ICP8. We found that single-stranded oligomers raise the melting temperature of ICP8 in a length- and concentration-dependent manner, ranging from 1 °C f...

  12. Ligand induced stabilization of the melting temperature of the HSV-1 single-strand DNA binding protein using the thermal shift assay

    Science.gov (United States)

    Rupesh, Kanchi Ravi; Smith, Aaron; Boehmer, Paul E.

    2014-01-01

    We have adapted the thermal shift assay to measure the ligand binding properties of the herpes simplex virus-1 single-strand DNA binding protein, ICP8. By measuring SYPRO Orange fluorescence in microtiter plates using a fluorescence-enabled thermal cycler, we have quantified the effects of oligonucleotide ligands on the melting temperature of ICP8. We found that single-stranded oligomers raise the melting temperature of ICP8 in a length- and concentration-dependent manner, ranging from 1 °C for (dT)5 to a maximum of 9 °C with oligomers ≥10 nucleotides, with an apparent Kd of <1 µM for (dT)20. Specifically, the results indicate that ICP8 is capable of interacting with oligomers as short as 5 nucleotides. Moreover, the observed increases in melting temperature of up to 9 °C, indicates that single-strand DNA binding significantly stabilizes the structure of ICP8. This assay may be applied to investigate the ligand binding proteins of other single-strand DNA binding proteins and used as a high-throughput screen to identify compounds with therapeutic potential that inhibit single-strand DNA binding. As proof of concept, the single-strand DNA binding agent ciprofloxacin reduces the ligand induced stabilization of the melting temperature of ICP8 in a dose-dependent manner. PMID:25449284

  13. Ground-State Energy as a Simple Sum of Orbital Energies in Kohn-Sham Theory: A Shift in Perspective through a Shift in Potential

    CERN Document Server

    Levy, Mel

    2016-01-01

    It is observed that the exact interacting ground-state electronic energy of interest may be obtained directly, in principle, as a simple sum of orbital energies when a universal density-dependent term is added to $w\\left(\\left[ \\rho \\right];\\mathbf{r} \\right)$, the familiar Hartree plus exchange-correlation component in the Kohn-Sham effective potential. The resultant shifted potential, $\\bar{w}\\left(\\left[ \\rho \\right];\\mathbf{r} \\right)$, actually changes less on average than $w\\left(\\left[ \\rho \\right];\\mathbf{r} \\right)$ when the density changes, including the fact that $\\bar{w}\\left(\\left[ \\rho \\right];\\mathbf{r} \\right)$ does not undergo a discontinuity when the number of electrons increases through an integer. Thus the approximation of $\\bar{w}\\left(\\left[ \\rho \\right];\\mathbf{r} \\right)$ represents an alternative direct approach for the approximation of the ground-state energy and density.

  14. Shift and broadening of emission lines in Nd$^{3+}$:YAG laser crystal influenced by input energy

    Indian Academy of Sciences (India)

    POURMAND SEYED EBRAHIM; REZAEI GHASEM

    2016-06-01

    Spectroscopic properties of the flashlamp-pumped Nd$^{3+}$:YAG laser as a function of input energy were studied over the range of 18–75 J. The spectral widths and shifts of quasi-three-level and four-level inter-Stark emissions within the respective intermanifold transitions of $^4$F$_{3/2}$ $\\rightarrow$ $^{4}$I$_{9/2} $ and $^{4}$F$_{3/2}$ $\\rightarrow$ $^{4}$I$_{11/2}$ were investigated. The emission lines of $^{4}$F$_{3/2}$ $\\rightarrow$ $^{4}$I$_{9/2}$ shifted towards longer wavelength (red shift) and broadened, while the positions and linewidths of the $^{4}$F$_{3/2}$ $\\rightarrow$ $^{4}$I$_{11/2}$ transition lines remained constant by increasing the pumping energy. This is attributed to the thermal population as well as one-phonon and multiphonon emission processes in the ground state. This phenomenon degrades the output performance of the lasers.

  15. Energy-dependent phase shift analysis of pion-nucleon scattering below 400 MeV

    International Nuclear Information System (INIS)

    An analytic function of energy is fit to the available S, P, and D wave πN phase shifts of various goups below 400 MeV. This global average, which reproduces well most of the experiment cross sections, is anticipated to be useful in pion-nucleus and pion-nucleon interaction calculations

  16. Decay widths and energy shifts of pi pi and pi K atoms

    OpenAIRE

    J. Schweizer

    2004-01-01

    We calculate the S-wave decay widths and energy shifts for pi pi and pi K atoms in the framework of QCD+QED. The evaluation - valid at next-to-leading order in isospin symmetry breaking - is performed within a non-relativistic effective field theory. The results are of interest for future hadronic atom experiments.

  17. New technique for phase shift analysis multi-energy solution of inverse scattering problem

    CERN Document Server

    Cooper, S G; MacIntosh, R S; Kuznetsova, E V

    1998-01-01

    We demonstrate a new approach to the analysis of extensive multi-energy data. For the case of d + He-4, we produce a phase shift analysis covering for the energy range 3 to 11 MeV. The key idea is the use of iterative perturbative data-to-potential inversion which can produce potentials which reproduce the data simultaneously over a range of energies. It thus effectively regularizes the extraction of phase shifts from diverse, incomplete and possibly somewhat contradictory data sets. In doing so, it will provide guidance to experimentalists as to what further measurements should be made. This study is limited to vector spin observables and spin-orbit interactions. We discuss alternative ways in which the theory can be implemented and which provide insight into the ambiguity problems. We compare the extrapolation of these solutions to other energies. Majorana terms are presented for each potential component.

  18. The Pressure-Induced Shifts of Energy Spectra of ZnSe:Ni2+

    Institute of Scientific and Technical Information of China (English)

    MA Dong-Ping; CHEN Ju-Rong; MA Ning

    2001-01-01

    The calculations of the whole energy spectrum of ZnSe:Ni2+ at normal pressure and pressure-induced shifts of its levels have been carried out on the basis of the theory of pressure-induced shifts and the diagonalization of the complete ds energy matrix in a regular tetrahedral field. The calculated results are in very good agreement with experimental data at normal and various pressures. By taking into account the pressure-induced shifts of spectral bands, the new assignments of bands are given. The comparison between the results of ZnSe:Ni2+ and MgO:Ni2+ shows that the covaJency of the bonding between Ni2+ and ligands (Se2-) in ZnSe:Ni2+ is obviously stronger than the one of the bonding between Ni2+ and ligands (O2-) in MgO:Ni2+ ; the expansion of electron wavefunctions of Ni2+ in ZnSe:Ni2+ under pressure is obviously larger than that of Ni2+ in MgO:Ni2+ under pressure. On the basis of these results, the physical origins of the remarkable difference between the pressure-induced shifts of levels of ZnSe:Ni2+ and those of MgO:Ni2+ are explained. It is found that the large expansion of electron wavefunctions and a phase transition of ZnSe:Ni2+ make the pressure-induced shifts of levels of ZnSe:Ni2+ strongly nonlinear.

  19. New horizons for Korean energy industry--shifting paradigms and challenges ahead

    International Nuclear Information System (INIS)

    Korean energy industry is experiencing a radical paradigm shift. Vertically integrated monopoly is being dismantled while state-owned energy companies are privatized. The industry is in transition from extensive government control to more flexible and market-oriented operation. Along with the task of successfully implementing these structural changes, Korea is now faced with challenges of addressing energy security with the decentralized supply system. This paper discusses ongoing efforts to transform electric power and natural gas industries in Korea, and then explores possible schemes for regional energy cooperation that will enhance efficiency and supply security

  20. Binding energies of indirect excitons in double quantum well systems

    Science.gov (United States)

    Rossokhaty, Alex; Schmult, Stefan; Dietsche, Werner; von Klitzing, Klaus; Kukushkin, Igor

    2011-03-01

    A prerequisite towards Bose-Einstein condensation is a cold and dense system of bosons. Indirect excitons in double GaAs/AlGaAs quantum wells (DQWs) are believed to be suitable candidates. Indirect excitons are formed in asymmetric DQW structures by mass filtering, a method which does not require external electric fields. The exciton density and the electron-hole balance can be tuned optically. Binding energies are measured by a resonant microwave absorption technique. Our results show that screening of the indirect excitons becomes already relevant at densities as low as ~ 5 × 109 cm-2 and results in their destruction.

  1. Minimalistic predictor of protein binding energy: contribution of solvation factor to protein binding.

    Science.gov (United States)

    Choi, Jeong-Mo; Serohijos, Adrian W R; Murphy, Sean; Lucarelli, Dennis; Lofranco, Leo L; Feldman, Andrew; Shakhnovich, Eugene I

    2015-02-17

    It has long been known that solvation plays an important role in protein-protein interactions. Here, we use a minimalistic solvation-based model for predicting protein binding energy to estimate quantitatively the contribution of the solvation factor in protein binding. The factor is described by a simple linear combination of buried surface areas according to amino-acid types. Even without structural optimization, our minimalistic model demonstrates a predictive power comparable to more complex methods, making the proposed approach the basis for high throughput applications. Application of the model to a proteomic database shows that receptor-substrate complexes involved in signaling have lower affinities than enzyme-inhibitor and antibody-antigen complexes, and they differ by chemical compositions on interfaces. Also, we found that protein complexes with components that come from the same genes generally have lower affinities than complexes formed by proteins from different genes, but in this case the difference originates from different interface areas. The model was implemented in the software PYTHON, and the source code can be found on the Shakhnovich group webpage: http://faculty.chemistry.harvard.edu/shakhnovich/software. PMID:25692584

  2. Electromagnetic corrections to the hadronic phase shifts in low energy pi sup + p elastic scattering

    CERN Document Server

    Gashi, A; Oades, G C; Rasche, G; Woolcock, W S

    2001-01-01

    We calculate for the s-, p sub 1 sub / sub 2 - and p sub 3 sub / sub 2 -waves the electromagnetic corrections which must be subtracted from the nuclear phase shifts obtained from the analysis of low-energy pi sup + p elastic scattering data, in order to obtain hadronic phase shifts. The calculation uses relativised Schroedinger equations containing the sum of an electromagnetic potential and an effective hadronic potential. We compare our results with those of previous calculations and estimate the uncertainties in the corrections.

  3. Charge reorganization energy and small polaron binding energy of rubrene thin films by ultraviolet photoelectron spectroscopy.

    Science.gov (United States)

    Duhm, Steffen; Xin, Qian; Hosoumi, Shunsuke; Fukagawa, Hirohiko; Sato, Kazushi; Ueno, Nobuo; Kera, Satoshi

    2012-02-14

    The hole–phonon coupling of a rubrene monolayer on graphite is measured by means of angle resolved ultraviolet photoelectron spectroscopy. Thus, the charge reorganization energy λ and the small polaron binding energy is determined, which allows insight into the nature of charge transport in condensed rubrene. PMID:22403829

  4. Mutation-Induced Population Shift in the MexR Conformational Ensemble Disengages DNA Binding: A Novel Mechanism for MarR Family Derepression.

    Science.gov (United States)

    Anandapadamanaban, Madhanagopal; Pilstål, Robert; Andresen, Cecilia; Trewhella, Jill; Moche, Martin; Wallner, Björn; Sunnerhagen, Maria

    2016-08-01

    MexR is a repressor of the MexAB-OprM multidrug efflux pump operon of Pseudomonas aeruginosa, where DNA-binding impairing mutations lead to multidrug resistance (MDR). Surprisingly, the crystal structure of an MDR-conferring MexR mutant R21W (2.19 Å) presented here is closely similar to wild-type MexR. However, our extended analysis, by molecular dynamics and small-angle X-ray scattering, reveals that the mutation stabilizes a ground state that is deficient of DNA binding and is shared by both mutant and wild-type MexR, whereas the DNA-binding state is only transiently reached by the more flexible wild-type MexR. This population shift in the conformational ensemble is effected by mutation-induced allosteric coupling of contact networks that are independent in the wild-type protein. We propose that the MexR-R21W mutant mimics derepression by small-molecule binding to MarR proteins, and that the described allosteric model based on population shifts may also apply to other MarR family members. PMID:27427478

  5. Adapting photosynthesis to the near-infrared: non-covalent binding of phycocyanobilin provides an extreme spectral red-shift to phycobilisome core-membrane linker from Synechococcus sp. PCC7335.

    Science.gov (United States)

    Miao, Dan; Ding, Wen-Long; Zhao, Bao-Qing; Lu, Lu; Xu, Qian-Zhao; Scheer, Hugo; Zhao, Kai-Hong

    2016-06-01

    Phycobiliproteins that bind bilins are organized as light-harvesting complexes, phycobilisomes, in cyanobacteria and red algae. The harvested light energy is funneled to reaction centers via two energy traps, allophycocyanin B and the core-membrane linker, ApcE1 (conventional ApcE). The covalently bound phycocyanobilin (PCB) of ApcE1 absorbs near 660 nm and fluoresces near 675 nm. In cyanobacteria capable of near infrared photoacclimation, such as Synechococcus sp. PCC7335, there exist even further spectrally red shifted components absorbing >700 nm and fluorescing >710 nm. We expressed the chromophore domain of the extra core-membrane linker from Synechococcus sp. PCC7335, ApcE2, in E. coli together with enzymes generating the chromophore, PCB. The resulting chromoproteins, PCB-ApcE2(1-273) and the more truncated PCB-ApcE2(24-245), absorb at 700 nm and fluoresce at 714 nm. The red shift of ~40 nm compared with canonical ApcE1 results from non-covalent binding of the chromophore by which its full conjugation length including the Δ3,3(1) double bond is preserved. The extreme spectral red-shift could not be ascribed to exciton coupling: dimeric PCB-ApcE2(1-273) and monomeric-ApcE2(24-245) absorbed and fluoresced similarly. Chromophorylation of ApcE2 with phycoerythrobilin- or phytochromobilin resulted in similar red shifts (absorption at 615 and 711 nm, fluorescence at 628 or 726 nm, respectively), compared to the covalently bound chromophores. The self-assembled non-covalent chromophorylation demonstrates a novel access to red and near-infrared emitting fluorophores. Brightly fluorescent biomarking was exemplified in E. coli by single-plasmid transformation.

  6. Adapting photosynthesis to the near-infrared: non-covalent binding of phycocyanobilin provides an extreme spectral red-shift to phycobilisome core-membrane linker from Synechococcus sp. PCC7335.

    Science.gov (United States)

    Miao, Dan; Ding, Wen-Long; Zhao, Bao-Qing; Lu, Lu; Xu, Qian-Zhao; Scheer, Hugo; Zhao, Kai-Hong

    2016-06-01

    Phycobiliproteins that bind bilins are organized as light-harvesting complexes, phycobilisomes, in cyanobacteria and red algae. The harvested light energy is funneled to reaction centers via two energy traps, allophycocyanin B and the core-membrane linker, ApcE1 (conventional ApcE). The covalently bound phycocyanobilin (PCB) of ApcE1 absorbs near 660 nm and fluoresces near 675 nm. In cyanobacteria capable of near infrared photoacclimation, such as Synechococcus sp. PCC7335, there exist even further spectrally red shifted components absorbing >700 nm and fluorescing >710 nm. We expressed the chromophore domain of the extra core-membrane linker from Synechococcus sp. PCC7335, ApcE2, in E. coli together with enzymes generating the chromophore, PCB. The resulting chromoproteins, PCB-ApcE2(1-273) and the more truncated PCB-ApcE2(24-245), absorb at 700 nm and fluoresce at 714 nm. The red shift of ~40 nm compared with canonical ApcE1 results from non-covalent binding of the chromophore by which its full conjugation length including the Δ3,3(1) double bond is preserved. The extreme spectral red-shift could not be ascribed to exciton coupling: dimeric PCB-ApcE2(1-273) and monomeric-ApcE2(24-245) absorbed and fluoresced similarly. Chromophorylation of ApcE2 with phycoerythrobilin- or phytochromobilin resulted in similar red shifts (absorption at 615 and 711 nm, fluorescence at 628 or 726 nm, respectively), compared to the covalently bound chromophores. The self-assembled non-covalent chromophorylation demonstrates a novel access to red and near-infrared emitting fluorophores. Brightly fluorescent biomarking was exemplified in E. coli by single-plasmid transformation. PMID:27045046

  7. Decoding the nuclear genome using nuclear binding and fusion energies

    Science.gov (United States)

    Yablon, Jay R.

    2015-04-01

    In several publications the author has presented the theory that protons and neutrons and other baryons are the chromo-magnetic monopoles of Yang-Mills gauge theory and used that to deduce the up and down current quark masses from the tightly-known Q = 0 empirical electron mass and the neutron minus proton mass difference with commensurately high precision. This is then used as a springboard to closely fit a wide range of empirical nuclear binding and fusion energy data and to obtain the proton and neutron masses themselves within all experimental errors. This presentation will systematically pull all of this together and a) establishes that this way of defining current quark masses constitutes a valid measurement scheme, b) lays out the empirical support for this theory via observed nuclear binding and fusion energies as well as the proton and neutron masses themselves, c) solidifies the interface used to connect the theory to these empirical results and uncovers a mixing between the up and down current quark masses, and d) presents clearly how and why the underlying theory is very conservative, being no more and no less than a deductive mathematical synthesis of Maxwell's classical theory with both the electric and magnetic field equations merged into one, Yang-Mills gauge theory, Dirac fermion theory, the Fermi-Dirac-Pauli Exclusion Principle, and to get from classical chromodynamics to QCD, Feynman path integration.

  8. An Accurate Redetermination of the $^{118}Sn$ Binding Energy

    CERN Document Server

    Borzakov, S B; Faikow-Stanczyk, H; Grigoriev, Yu V; Panteleev, T; Pospísil, S; Smotritsky, L M; Telezhnikov, S A

    2001-01-01

    The energy of well-known strong {gamma}-line from {{^198}Au}, the "gold standard", has been modified in the light of new adjustments in the fundamental constants and the value of 411.80176(12) keV was determined which is 0.29 eV lower than the latest 1999 value. An energy calibration procedure for determining the neutron binding energy, {B_n}, from complicated {(n , gamma)}-spectra has been developed. A mathematically simple minimization function consisting only of terms having as parameters the coefficients of the energy calibration curve (polynomial) is used. A priori information about the relationships among the energies of different peaks on the spectrum is taking into account by a Monte Carlo simulation. The procedure was used in obtaining of {B_n} for {{^118}Sn} and {{^64}Cu}. The {gamma}-ray spectrum from thermal neutron radiative capture by {{^117}Sn} has been measured on the IBR-2 pulsed reactor. {gamma}-rays were detected by a 72 cm^3 HPGe-detector. {B_n} for {{^64}Cu} was obtained from two {gamma}-...

  9. Effect of hydrostatic pressure and polaronic mass of the binding energy in a spherical quantum dot

    Institute of Scientific and Technical Information of China (English)

    A. Rejo Jeice; Sr. Gerardin Jayam; K. S. Joseph Wilson

    2015-01-01

    Simultaneous effect of hydrostatic pressure and polaronic mass on the binding energies of the ground and excited states of an on-center hydrogenic impurity confined in a GaAs/GaAlAs spherical quantum dot are theoretically investigated by the variational method within the effective mass approximation. The binding energy is calculated as a function of dot radius and pressure. Our findings proved that the hydrostatic pressure led to the decrease of confined energy and the increase of donor binding energy. Conduction band non-parabolicity and the polaron masses are effective in the donor binding energy which is significant for narrow dots not in the confined energy. The maximum donor binding energy achieved by the polaronic mass in the ground and excited states are 2%–19%for the narrow dots. The confined and donor binding energies approach zero as the dot size approaches infinity.

  10. Electronic structure and binding energy relaxation of ScZr atomic alloying

    Science.gov (United States)

    Bo, Maolin; Guo, Yongling; Yang, Xuexian; He, Junjie; Liu, Yonghui; Peng, Cheng; Huang, Yongli; Sun, Chang Q.

    2016-07-01

    We examined the combined effect of atomic under- and hetero-coordination on the bond relaxation and electronic binding energy of Sc, Zr, and ScZr alloying using a combination of the bond-order-length-strength (BOLS) correlation and density functional theory (DFT) calculations. Observations strongly emphasize the relevance of core-level shifts as reliable X-ray photoelectron spectroscopy experimental descriptors of core-shell catalysis reactivity, along with under-coordinated atoms in bimetallic transition metal systems. The BOLS-DFT method provides enhanced catalysis reactivity and detects surface and alloy configurations, opening up the possibility to investigate more complex systems with irregularly under- and hetero-coordinated atoms.

  11. Integrated biomass and solar town: Incorporation of load shifting and energy storage

    International Nuclear Information System (INIS)

    The IBS (Integrated Biomass Solar) town is a concept which encourages local community to utilize biomass waste comprehensively with strong ties between community and local stakeholders. This paper discusses an IBS model and solution for an electrically self-sufficient eco-village with and without LS (load shifting). ES (energy storage) is also incorporated to help reduce electricity demand during peak periods and smooth variations in power generation by variable generation of solar power. Application to a realistic case study shows that substantial technical and economic benefits are achieved through the implementation of IBS with LS and ES. In this study, the LS is used mainly to increase demand during periods of high supply and also shift the load to intervals with low demand. This reduces the size of ES significantly, where the load is subject to distinct weekday and weekend profiles. The study shows that highly competitive electricity prices are obtained and the concept offers the opportunity to spur economic growth and environmental protection through energy efficiency improvement and deployment of low-carbon technologies. - Highlights: • A hybrid energy system for designing and optimizing RE resource utilization. • The load shifting and energy storage are incorporated. • The proposed model is demonstrated on an Iskandar Malaysia case study. • The optimal power generation scheme and power generation schedule are determined

  12. Thermodynamics and phase transitions in dense hydrogen - the role of bound state energy shifts

    International Nuclear Information System (INIS)

    In recent papers we have investigated the effects of Pauli blocking on the energy shifts in dense hydrogen. As Pauli blocking we denote effects on the shifts which result from the antisymmetry of the electronic wave functions. Here we study of the thermodynamic properties of dense hydrogen including the influence of energy shifts. Of special interest is the region where a transition from insulating behavior to metal-like conductivity has been shown experimentally. In this region, Pauli blocking effects have a deciding influence on this transition. Assuming that the system is a gas-like mixture of chemical species, the ionization equilibrium is treated by an advanced chemical approach. We calculate the Pauli and Fock shifts by perturbation theory and variational methods and construct useful interpolation formulae. Results for the ionization equilibrium are presented for temperatures between 4000 K23 cm-3 where the transition from a neutral hydrogen gas to a highly ionized plasma occurs. The results for the equation of state and the relative pressure indicate that the transition to a highly conducting state is softer than derived in earlier work. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Microsolvation effects on the electron binding energies of halide anions

    Science.gov (United States)

    Dolgounitcheva, O.; Zakrzewski, V. G.; Streit, L.; Ortiz, J. V.

    2014-02-01

    Ab initio electron propagator calculations in the partial third order (P3) and P3+ approximations were performed to obtain vertical electron detachment energies (VEDEs) of fluoride and chloride clusters with one through three molecules of water. Larger clusters of F- and Cl- with six water molecules were also treated with and without the polarisable continuum model (PCM). For the smaller clusters, good agreement between calculated VEDEs and peak positions in photoelectron spectra is achieved. Large shifts in VEDEs are observed for both hexameric fluoride-water and chloride-water complexes when the PCM is applied. Significant changes in coordination geometries about the chloride anion also occur in this model. In all fluoride complexes, Dyson orbitals for the lowest VEDEs are delocalised over oxygen atoms. On the contrary, for the case of chloride-water clusters, the Dyson orbitals corresponding to the lowest VEDEs are localised on the anion.

  14. Calculation of absolute free energy of binding for theophylline and its analogs to RNA aptamer using nonequilibrium work values

    Energy Technology Data Exchange (ETDEWEB)

    Tanida, Yoshiaki [Fujitsu Laboratories Ltd., 10-1 Morinosato-Wakamiya, Atsugi, Kanagawa (Japan)], E-mail: tanida@labs.fujitsu.com; Ito, Masakatsu; Fujitani, Hideaki [Fujitsu Laboratories Ltd., 10-1 Morinosato-Wakamiya, Atsugi, Kanagawa (Japan)

    2007-08-16

    The massively parallel computation of absolute binding free energy with a well-equilibrated system (MP-CAFEE) has been developed [H. Fujitani, Y. Tanida, M. Ito, G. Jayachandran, C.D. Snow, M.R. Shirts, E.J. Sorin, V.S. Pande, J. Chem. Phys. 123 (2005) 084108]. As an application, we perform the binding affinity calculations of six theophylline-related ligands with RNA aptamer. Basically, our method is applicable when using many compute nodes to accelerate simulations, thus a parallel computing system is also developed. To further reduce the computational cost, the adequate non-uniform intervals of coupling constant {lambda}, connecting two equilibrium states, namely bound and unbound, are determined. The absolute binding energies {delta}G thus obtained have effective linear relation between the computed and experimental values. If the results of two other different methods are compared, thermodynamic integration (TI) and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) by the paper of Gouda et al. [H. Gouda, I.D. Kuntz, D.A. Case, P.A. Kollman, Biopolymers 68 (2003) 16], the predictive accuracy of the relative values {delta}{delta}G is almost comparable to that of TI: the correlation coefficients (R) obtained are 0.99 (this work), 0.97 (TI), and 0.78 (MM-PBSA). On absolute binding energies meanwhile, a constant energy shift of {approx}-7 kcal/mol against the experimental values is evident. To solve this problem, several presumable reasons are investigated.

  15. Calculation of absolute free energy of binding for theophylline and its analogs to RNA aptamer using nonequilibrium work values

    Science.gov (United States)

    Tanida, Yoshiaki; Ito, Masakatsu; Fujitani, Hideaki

    2007-08-01

    The massively parallel computation of absolute binding free energy with a well-equilibrated system (MP-CAFEE) has been developed [H. Fujitani, Y. Tanida, M. Ito, G. Jayachandran, C.D. Snow, M.R. Shirts, E.J. Sorin, V.S. Pande, J. Chem. Phys. 123 (2005) 084108]. As an application, we perform the binding affinity calculations of six theophylline-related ligands with RNA aptamer. Basically, our method is applicable when using many compute nodes to accelerate simulations, thus a parallel computing system is also developed. To further reduce the computational cost, the adequate non-uniform intervals of coupling constant λ, connecting two equilibrium states, namely bound and unbound, are determined. The absolute binding energies Δ G thus obtained have effective linear relation between the computed and experimental values. If the results of two other different methods are compared, thermodynamic integration (TI) and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) by the paper of Gouda et al. [H. Gouda, I.D. Kuntz, D.A. Case, P.A. Kollman, Biopolymers 68 (2003) 16], the predictive accuracy of the relative values ΔΔ G is almost comparable to that of TI: the correlation coefficients ( R) obtained are 0.99 (this work), 0.97 (TI), and 0.78 (MM-PBSA). On absolute binding energies meanwhile, a constant energy shift of ˜-7 kcal/mol against the experimental values is evident. To solve this problem, several presumable reasons are investigated.

  16. Calculation of absolute free energy of binding for theophylline and its analogs to RNA aptamer using nonequilibrium work values

    International Nuclear Information System (INIS)

    The massively parallel computation of absolute binding free energy with a well-equilibrated system (MP-CAFEE) has been developed [H. Fujitani, Y. Tanida, M. Ito, G. Jayachandran, C.D. Snow, M.R. Shirts, E.J. Sorin, V.S. Pande, J. Chem. Phys. 123 (2005) 084108]. As an application, we perform the binding affinity calculations of six theophylline-related ligands with RNA aptamer. Basically, our method is applicable when using many compute nodes to accelerate simulations, thus a parallel computing system is also developed. To further reduce the computational cost, the adequate non-uniform intervals of coupling constant λ, connecting two equilibrium states, namely bound and unbound, are determined. The absolute binding energies ΔG thus obtained have effective linear relation between the computed and experimental values. If the results of two other different methods are compared, thermodynamic integration (TI) and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) by the paper of Gouda et al. [H. Gouda, I.D. Kuntz, D.A. Case, P.A. Kollman, Biopolymers 68 (2003) 16], the predictive accuracy of the relative values ΔΔG is almost comparable to that of TI: the correlation coefficients (R) obtained are 0.99 (this work), 0.97 (TI), and 0.78 (MM-PBSA). On absolute binding energies meanwhile, a constant energy shift of ∼-7 kcal/mol against the experimental values is evident. To solve this problem, several presumable reasons are investigated

  17. Dynamics of suspended microchannel resonators conveying opposite internal fluid flow: Stability, frequency shift and energy dissipation

    Science.gov (United States)

    Zhang, Wen-Ming; Yan, Han; Jiang, Hui-Ming; Hu, Kai-Ming; Peng, Zhi-Ke; Meng, Guang

    2016-04-01

    In this paper, the dynamics of suspended microchannel resonators which convey internal flows with opposite directions are investigated. The fluid-structure interactions between the laminar fluid flow and oscillating cantilever are analyzed by comprehensively considering the effects of velocity profile, flow viscosity and added flowing particle. A new model is developed to characterize the dynamic behavior of suspended microchannel resonators with the fluid-structure interactions. The stability, frequency shift and energy dissipation of suspended microchannel resonators are analyzed and discussed. The results demonstrate that the frequency shifts induced by the added flowing particle which are obtained from the new model have a good agreement with the experimental data. The steady mean flow can cause the frequency shift and influence the stability of the dynamic system. As the flow velocity reaches the critical value, the coupled-mode flutter occurs via a Hamiltonian Hopf bifurcation. The perturbation flow resulted from the vibration of the microcantilever leads to energy dissipation, while the steady flow does not directly cause the damping which increases with the increasing of the flow velocity predicted by the classical model. It can also be found that the steady flow firstly changes the mode shape of the cantilever and consequently affects the energy dissipation.

  18. Double binding energy differences: Mean-field or pairing effect?

    Science.gov (United States)

    Qi, Chong

    2012-10-01

    In this Letter we present a systematic analysis on the average interaction between the last protons and neutrons in atomic nuclei, which can be extracted from the double differences of nuclear binding energies. The empirical average proton-neutron interaction Vpn thus derived from experimental data can be described in a very simple form as the interplay of the nuclear mean field and the pairing interaction. It is found that the smooth behavior as well as the local fluctuations of the Vpn in even-even nuclei with N ≠ Z are dominated by the contribution from the proton-neutron monopole interactions. A strong additional contribution from the isoscalar monopole interaction and isovector proton-neutron pairing interaction is seen in the Vpn for even-even N = Z nuclei and for the adjacent odd-A nuclei with one neutron or proton being subtracted.

  19. A dual-energy transmission detector for vehicle scanning using wavelength-shifting fibers

    Science.gov (United States)

    Van Liew, Seth; Zhang, Ming

    2014-09-01

    A new dual energy detector for vehicle scanning is presented. The system is composed of a three-sided Compton backscatter imaging system utilizing flying-spot x-rays concurrent with a transmission detector using the same x-ray beam. This detector is under the vehicle and is thin enough to be driven over with a modest bump which does not impede vehicle trac. It uses sheet scintillator with wavelength-shifting fibers as light pipes. Results are presented on steel penetration, calibration procedures and issues, and dual energy performance. The system's dose is low enough for scanning people, including passenger vehicles.

  20. Using Electrophoretic Mobility Shift Assays to Measure Equilibrium Dissociation Constants: GAL4-p53 Binding DNA as a Model System

    Science.gov (United States)

    Heffler, Michael A.; Walters, Ryan D.; Kugel, Jennifer F.

    2012-01-01

    An undergraduate biochemistry laboratory experiment is described that will teach students the practical and theoretical considerations for measuring the equilibrium dissociation constant (K[subscript D]) for a protein/DNA interaction using electrophoretic mobility shift assays (EMSAs). An EMSA monitors the migration of DNA through a native gel;…

  1. Energy calibration issues in nuclear resonant vibrational spectroscopy: observing small spectral shifts and making fast calibrations.

    Science.gov (United States)

    Wang, Hongxin; Yoda, Yoshitaka; Dong, Weibing; Huang, Songping D

    2013-09-01

    The conventional energy calibration for nuclear resonant vibrational spectroscopy (NRVS) is usually long. Meanwhile, taking NRVS samples out of the cryostat increases the chance of sample damage, which makes it impossible to carry out an energy calibration during one NRVS measurement. In this study, by manipulating the 14.4 keV beam through the main measurement chamber without moving out the NRVS sample, two alternative calibration procedures have been proposed and established: (i) an in situ calibration procedure, which measures the main NRVS sample at stage A and the calibration sample at stage B simultaneously, and calibrates the energies for observing extremely small spectral shifts; for example, the 0.3 meV energy shift between the 100%-(57)Fe-enriched [Fe4S4Cl4](=) and 10%-(57)Fe and 90%-(54)Fe labeled [Fe4S4Cl4](=) has been well resolved; (ii) a quick-switching energy calibration procedure, which reduces each calibration time from 3-4 h to about 30 min. Although the quick-switching calibration is not in situ, it is suitable for normal NRVS measurements.

  2. Energy shifts of Kα x rays from highly stripped sulfur ions traveling in solids

    International Nuclear Information System (INIS)

    The energies and intensities of the 2 3P1→1 1S0, and 2 1P1→1 1S0 transitions in He-like sulfur ions, and of the 22P→12S transition in H-like sulfur ions have been studied as a function of the thickness and electron density of the solid through which the ions travel. The thickness dependence of the x-ray intensities was analyzed in terms of a three-component model description of K-shell vacancy production and decay. Cross sections for electron excitation or ionization and capture deduced from this analysis were used to establish the energies of the x-ray peaks for complete emission in vacuum (i.e., outside the target). Energy shifts were obtained by comparing the peak energies for emission in thick targets to those for emission in vacuum. The results show that the energy shifts increase approximately linearly with the square root of the valence electron density of the target and are in good agreement with theoretical expectations

  3. Chemical shift as a probe of molecular interfaces: NMR studies of DNA binding by the three amino-terminal zinc finger domains from transcription factor IIIA

    Energy Technology Data Exchange (ETDEWEB)

    Foster, Mark P.; Wuttke, Deborah S.; Clemens, Karen R.; Jahnke, Wolfgang; Radhakrishnan, Ishwar; Tennant, Linda; Reymond, Martine; Chung, John; Wright, Peter E. [Scripps Research Institute, Department of Molecular Biology and Skaggs Institute for Chemical Biology (United States)

    1998-07-15

    We report the NMR resonance assignments for a macromolecular protein/DNA complex containing the three amino-terminal zinc fingers (92 amino acid residues) of Xenopus laevis TFIIIA (termed zf1-3) bound to the physiological DNA target (15 base pairs), and for the free DNA. Comparisons are made of the chemical shifts of protein backbone{sup 1} H{sup N}, {sup 15}N,{sup 13} C{sup {alpha}} and{sup 13} C{sup {beta}} and DNA base and sugar protons of the free and bound species. Chemical shift changes are analyzed in the context of the structures of the zf1-3/DNA complex to assess the utility of chemical shift change as a probe of molecular interfaces. Chemical shift perturbations that occur upon binding in the zf1-3/DNA complex do not correspond directly to the structural interface, but rather arise from a number of direct and indirect structural and dynamic effects.

  4. Binding Energies of a Positively Charged Exciton in a Quantum Disc

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The binding energies of the lowest singlet and triplet states of positively charged excitons confined to a quantum disc are studied using exact diagonalization techniques. We investigate the dependence of the binding energies on the confinement strength and on the effective electron-to-hole mass ratio. The results we have obtained show that the binding energies are closely correlated to the strength of the confinement potential and the effective electron-to-hole mass ratio.

  5. Electrophoretic mobility shift assays: analysis of tRNA binding to the T box riboswitch antiterminator RNA.

    Science.gov (United States)

    Anupam, R; Zhou, S; Hines, J V

    2015-01-01

    Changes in electrophoretic mobility upon complex formation with RNA can be used to probe structure-function relationships that are critical for complex formation. Here, we describe the application of this technique to monitor tRNA binding to the T box riboswitch antiterminator RNA. PMID:25352142

  6. Simultaneous effects of pressure and temperature on donor binding energy in Poeschl-Teller quantum well

    Energy Technology Data Exchange (ETDEWEB)

    Hakimyfard, Alireza; Barseghyan, M.G. [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia); Duque, C.A., E-mail: cduque@fisica.udea.edu.c [Instituto de Fisica, Universidad de Antioquia, AA 1226, Medellin (Colombia); Kirakosyan, A.A. [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia)

    2009-12-15

    In the frame of the variational method and the effective-mass approximation, the effects of hydrostatic pressure and temperature on the binding energy for donor impurities in the Poeschl-Teller quantum well are studied. The binding energy dependencies on the width of the quantum well, the hydrostatic pressure, the impurity position, the temperature, and the parameters of the confining potential are reported. The results show that the binding energy increases (decreases) with the increasing of the hydrostatic pressure (temperature). It is also found that, associated with the symmetry breaking in the Poeschl-Teller quantum well, and depending on the impurity position, the binding energy can increase or decrease.

  7. Transport Gap and exciton binding energy determination in organic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Stefan; Schoell, Achim; Reinert, Friedrich; Umbach, Eberhard [University of Wuerzburg (Germany). Experimental Physics II; Casu, Benedetta [Inst. f. Physik. u. Theor. Chemie, Tuebingen (Germany)

    2008-07-01

    The transport gap of an organic semiconductor is defined as the energy difference between the HOMO and LUMO levels in the presence of a hole or electron, respectively, after relaxation has occurred. Its knowledge is mandatory for the optimisation of electronic devices based on these materials. UV photoelectron spectroscopy (UPS) and inverse photoelectron spectroscopy (IPES) are routinely applied to measure these molecular levels. However, the precise determination of the transport gap on the basis of the respective data is not an easy task. It involves fundamental questions about the properties of organic molecules and their condensates, about their reaction on the experimental probe, and on the evaluation of the spectroscopic data. In particular electronic relaxation processes, which occur on the time scale of the photo excitation, have to be considered adequately. We determined the transport gap for the organic semiconductors PTCDA, Alq3, DIP, CuPc, and PBI-H4. After careful data analysis and comparison to the respective values for the optical gap we obtain values for the exciton binding energies between 0.1-0.5 eV. This is considerably smaller than commonly believed and indicates a significant delocalisation of the excitonic charge over various molecular units.

  8. Quantum-Confinement Effects on Binding Energies and Optical Properties of Excitons in Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    潘晖

    2004-01-01

    Quantum-confinement effects on the binding energy and the linear optical susceptibility of excitons in quantum dots are studied. It is found that the binding energy and the linear optical susceptibility are sensitive to the barrier height and the dot size. For an infinite barrier, the binding energy of excitons decreases monotonically with the increasing dot radius, and the absorption intensity has almost the same amplitude with the increasing photon energy. For a finite barrier, the binding energy has a maximum value with the increasing dot radius, and the absorption intensity damps rapidly with the increasing photon energy. The effective mass ratio is also found to have an influence on the binding energy. The results could be confirmed by future experiments on excitons in quantum dots.

  9. Long-term shifts in life-cycle energy efficiency and carbon intensity.

    Science.gov (United States)

    Yeh, Sonia; Mishra, Gouri Shankar; Morrison, Geoff; Teter, Jacob; Quiceno, Raul; Gillingham, Kenneth; Riera-Palou, Xavier

    2013-03-19

    The quantity of primary energy needed to support global human activity is in large part determined by how efficiently that energy is converted to a useful form. We estimate the system-level life-cycle energy efficiency (EF) and carbon intensity (CI) across primary resources for 2005-2100. Our results underscore that although technological improvements at each energy conversion process will improve technology efficiency and lead to important reductions in primary energy use, market mediated effects and structural shifts toward less efficient pathways and pathways with multiple stages of conversion will dampen these efficiency gains. System-level life-cycle efficiency may decrease as mitigation efforts intensify, since low-efficiency renewable systems with high output have much lower GHG emissions than some high-efficiency fossil fuel systems. Climate policies accelerate both improvements in EF and the adoption of renewable technologies, resulting in considerably lower primary energy demand and GHG emissions. Life-cycle EF and CI of useful energy provide a useful metric for understanding dynamics of implementing climate policies. The approaches developed here reiterate the necessity of a combination of policies that target efficiency and decarbonized energy technologies. We also examine life-cycle exergy efficiency (ExF) and find that nearly all of the qualitative results hold regardless of whether we use ExF or EF. PMID:23409918

  10. Total binding energy via the band structure energy of 4d group transition metals

    International Nuclear Information System (INIS)

    The binding in metals provides a basis genesis to discuss the cohesive, elastic, lattice dynamical and other allied properties of the metals. A thorough and comprehensive analysis with regard to (i) various energy terms contributing to total metallic bonding, (ii) forms of the model potential incurring the band structure part of the binding, (iii) implication of s-d hybridization and (iv) effect of electron screening, has prompted us to undertake the present study of binding in several complex metals which turn out to be superconducting at low temperatures and bear hcp, bcc and fcc configurations at room temperature i.e. yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh) and palladium (Pd). (author). 13 refs., 2 figs., 2 tabs

  11. Pronounced polarization-induced energy level shifts at boundaries of organic semiconductor nanostructures

    Science.gov (United States)

    Cochrane, K. A.; Schiffrin, A.; Roussy, T. S.; Capsoni, M.; Burke, S. A.

    2015-10-01

    Organic semiconductor devices rely on the movement of charge at and near interfaces, making an understanding of energy level alignment at these boundaries an essential element of optimizing materials for electronic and optoelectronic applications. Here we employ low temperature scanning tunneling microscopy and spectroscopy to investigate a model system: two-dimensional nanostructures of the prototypical organic semiconductor, PTCDA (3,4,9,10-perylenetetracarboxylic dianhydride) adsorbed on NaCl (2 ML)/Ag(111). Pixel-by-pixel scanning tunneling spectroscopy allows mapping of occupied and unoccupied electronic states across these nanoislands with sub-molecular spatial resolution, revealing strong electronic differences between molecules at the edges and those in the centre, with energy level shifts of up to 400 meV. We attribute this to the change in electrostatic environment at the boundaries of clusters, namely via polarization of neighbouring molecules. The observation of these strong shifts illustrates a crucial issue: interfacial energy level alignment can differ substantially from the bulk electronic structure in organic materials.

  12. Phase-Shift Analysis of Low-Energy $\\pi^{+}p$ Data

    CERN Document Server

    Gashi, A; Oades, G C; Rasche, G; Woolcock, W S

    1999-01-01

    This work presents the results of a revised analysis of the low-energy (pion laboratory kinetic energy T(sub pi) < 100 MeV) pi+ p data using recently obtained electromagnetic corrections. The measurements are analyzed assuming extended threshold expansions for the hadronic K-matrix elements. With a few exceptions, the description of the experimental data is satisfactory. Several minimization functions have been used, yielding consistent results. The phase-shift values, obtained in the s and p(3/2) partial waves, disagree with those of the most recent VPI global-fit solution (SP98); the largest part of this disagreement is removed if we compare our numbers to their single-energy solutions. The s-wave scattering length a(sub 0+), the p-wave scattering volumes a(sub 1+) and a(sub 1-), as well as the hadronic phase shifts themselves, obtained herein, are in agreement with recent work using older electromagnetic corrections; the output of the present work (including meaningful uncertainties) is tabulated in ord...

  13. Phase-shift analysis of low-energy $\\pi^{\\pm}p$ elastic-scattering data

    CERN Document Server

    Matsinos, E; Oades, G C; Rasche, G; Woolcock, W S

    2006-01-01

    Using electromagnetic corrections previously calculated by means of a potential model, we have made a phase-shift analysis of the $\\pi^\\pm p$ elastic-scattering data up to a pion laboratory kinetic energy of 100 MeV. The hadronic interaction was assumed to be isospin invariant. We found that it was possible to obtain self-consistent databases by removing very few measurements. A pion-nucleon model was fitted to the elastic-scattering database obtained after the removal of the outliers. The model-parameter values showed an impressive stability when the database was subjected to different criteria for the rejection of experiments. Our result for the pseudovector $\\pi N N$ coupling constant (in the standard form) is $0.0733 \\pm 0.0014$. The six hadronic phase shifts up to 100 MeV are given in tabulated form. We also give the values of the s-wave scattering lengths and the p-wave scattering volumes. Big differences in the s-wave part of the interaction were observed when comparing our hadronic phase shifts with t...

  14. Development of continuous-energy eigenvalue sensitivity coefficient calculation methods in the shift Monte Carlo Code

    Energy Technology Data Exchange (ETDEWEB)

    Perfetti, C.; Martin, W. [Univ. of Michigan, Dept. of Nuclear Engineering and Radiological Sciences, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109-2104 (United States); Rearden, B.; Williams, M. [Oak Ridge National Laboratory, Reactor and Nuclear Systems Div., Bldg. 5700, P.O. Box 2008, Oak Ridge, TN 37831-6170 (United States)

    2012-07-01

    Three methods for calculating continuous-energy eigenvalue sensitivity coefficients were developed and implemented into the Shift Monte Carlo code within the SCALE code package. The methods were used for two small-scale test problems and were evaluated in terms of speed, accuracy, efficiency, and memory requirements. A promising new method for calculating eigenvalue sensitivity coefficients, known as the CLUTCH method, was developed and produced accurate sensitivity coefficients with figures of merit that were several orders of magnitude larger than those from existing methods. (authors)

  15. The spectral shift function for planar obstacle scattering at low energy

    CERN Document Server

    McGillivray, I E

    2011-01-01

    Let $H$ signify the free non-negative Laplacian on $\\mathbb{R}^2$ and $H_Y$ the non-negative Dirichlet Laplacian on the complement $Y$ of a nonpolar compact subset $K$ in the plane. We derive the low-energy expansion for the Krein spectral shift function (scattering phase) for the obstacle scattering system $\\{\\,H_Y,\\,H\\,\\}$ including detailed expressions for the first three coefficients. We use this to investigate the large time behaviour of the expected volume of the pinned Wiener sausage associated to $K$.

  16. Effect of the isovector coupling channel on the macroscopic part of the nuclear binding energy

    Indian Academy of Sciences (India)

    S Haddad

    2013-05-01

    The effect of isovector coupling channel on the macroscopic part of the nuclear binding energy is studied using the relativistic density-dependent Thomas–Fermi approach. The dependency of this effect on the number of neutrons and protons is also studied. The isovector coupling channel leads to increased nuclear binding energy, and this effect increases with the increasing neutron number in the nucleus.

  17. Biexciton binding energy in ZnSe quantum wells and quantum wires

    DEFF Research Database (Denmark)

    Wagner, Hans-Peter; Langbein, Wolfgang; Hvam, Jørn Märcher;

    2002-01-01

    The biexciton binding energy E-XX is investigated in ZnSe/ZnMgSe quantum wells and quantum wires as a function of the lateral confinement by transient four-wave mixing. In the quantum wells one observes for decreasing well width a significant increase in the relative binding energy, saturating...

  18. Consumer response to product-integrated energy feedback: behavior, goal level shifts, and energy conservation

    NARCIS (Netherlands)

    McCalley, L.T.; Vries, de Peter W.; Midden, Cees J.H.

    2011-01-01

    Results of recent experiments suggest that interactive control panels of individual appliances can be used to stimulate energy saving behavior by offering the means for consumers to set a goal and receive immediate energy use feedback. The underlying source of the behavioral response, however, remai

  19. Calculations of hydrogen atom multiphoton energy level shifts, transition amplitudes and ionization probabilities

    International Nuclear Information System (INIS)

    Analyses of the resonant multiphoton ionization of atoms require knowledge of ac Stark energy shifts and of multiphoton, bound-to-bound state, transition amplitudes. In this paper, we consider the three-photon photoionization of hydrogen atoms at frequencies that are at and surrounding the two-photon 1s to 2s resonance. AC energy shift sums of both the 1s and 2s states are calculated as a function of the laser frequency along with two-photon 1s → 2s resonant transition amplitude sums. These quantities are calculated using an extended version of a method, which has often been employed in a variety of ways, of calculating these sums by expressing them in terms of solutions to a variety of differential equations that are derived from the different sums being evaluated. We demonstrate how exact solutions are obtained to these differential equations, which lead to exact evaluations of the corresponding sums. A variety of different cases are analysed, some involving analytic continuation, some involving real number analysis and some involving complex number analysis. A dc Stark sum calculation of the 2s state is carried out to illustrate the case where analytic continuation, pole isolation and pole subtraction are required and where the calculation can be carried out analytically; the 2s state, ac Stark shift sum calculations involve a case where no analytic continuation is required, but where the solution to the differential equation produces complex numbers owing to the finite photoionization lifetime of the 2s state. Results from these calculations are then used to calculate three-photon ionization probabilities of relevance to an analysis of the multiphoton ionization data published by Kyrala and Nichols (1991 Phys. Rev. A 44, R1450)

  20. Binding energy and optical properties of an off-center hydrogenic donor impurity in a spherical quantum dot placed at the center of a cylindrical nano-wire

    International Nuclear Information System (INIS)

    The binding energy as well as the linear, third-order nonlinear and total optical absorption coefficient and refractive index changes of an off-center hydrogenic donor impurity in an InAs spherical quantum dot placed at the center of a GaAs cylindrical nano-wire have been investigated. In this regard, the effective-mass approximation approach is considered and eigenvalues and corresponding eigenfunctions are calculated via the finite element method. The binding energy is plotted as a function of the dot size and impurity position along with optical properties as a function of photon energy. In this study two different directions have been considered for impurity position, along the nano-wire axis and perpendicular to it. It has been found that the binding energy, absorption coefficient and refractive index changes are impressively affected not only by the dot radius but also by the position of the impurity and its direction. Additionally, the optical saturation can be tuned by the direction of the impurity and incident optical intensity. -- Highlights: • We consider spherical quantum dot located at the center of a cylindrical nano-wire. • An off-center hydrogenic donor impurity is considered in the system. • Binding energy is affected by orientation of impurity and its distance from center. • Saturation depends on the orientation of impurity position. • By shifting impurity position, orientation and dot radius blue- and red-shifts appear

  1. The shift of the public opinion to the favour of nuclear energy in Slovenia

    International Nuclear Information System (INIS)

    In late August and early September of 1999, nuclear energy topics occupied a central place in the Slovenian media because of the transport of two new steam generators to the Krsko nuclear power plant, and also due to the protest action of an Austrian Greenpeace group. Before these events, the public opinion in Slovenia was not in favour or nuclear energy and Greenpeace had a good reputation. In September it has lost much credibility because of their clumsy action of protest, and in just one month this caused a shift of public opinion in Slovenia towards support of Slovenia's only nuclear power plant. The Greenpeace protest action occurred during the transport of the two new steam generators to Krsko. By replacement of the old steam generators the operation of the Krsko NPP will be extended until 2023. The transport envoy travelled during the first half of September '99 across a considerable part of Slovene territory, passing by the capital of Ljubljana. (authors)

  2. Climate and health impacts of the shift from traditional solid cookstove fuels to modern energy sources

    Science.gov (United States)

    Lacey, F.; Henze, D. K.; Martin, R.; Lee, C. J.; van Donkelaar, A.; Reed, L.

    2015-12-01

    Globally, 2.8 million people use solid fuels for meal preparation. As regions in which solid fuel cooking is prevalent become more industrialized, this number will decrease leading to commensurate changes in greenhouse gas, aerosol and aerosol precursor emissions from the residential sector. Here we explore the impacts of this shift from traditional solid fuel use to equivalent energy sources from modern power generation on climate change and exposure to ambient air pollution. We use sensitivities calculated with the GEOS-Chem adjoint model, which allows us to estimate the climate and health impacts due to changes in atmospheric composition from grid-scale shifts in energy usage. Various scenarios for alternative energy generation sources are considered. Climate impacts are reported as changes in global averaged surface temperature through the use of absolute regional temperature potentials and health impacts are reported as changes in premature deaths calculated using changes in population-weighted PM2.5 concentrations combined with integrated exposure response functions. Global model PM2.5 surface concentrations are downscaled to improve exposure estimates through application of remotely sensed aerosol optical depth measurements. Our assessment of the impacts of fuel switching allows for estimates of upper and lower bounds, for both climate and health impacts, at the global and national scale. Baseline calculations using these methods estimate impacts of approximately 0.22 K warming and 217,000 premature deaths caused by changes in ambient air quality due to present day cookstove emissions which represents the base case for these comparisons. Overall, the results of this study provide important information to both individual country's governments and non-governmental organizations that are targeting energy infrastructure improvements.

  3. Free energy of binding of a small molecule to an amorphous polymer in a solvent.

    Science.gov (United States)

    Chunsrivirot, Surasak; Trout, Bernhardt L

    2011-06-01

    Crystallization is a commonly used purification process in industrial practice. It usually begins with heterogeneous nucleation on a foreign surface. The complicated mechanism of heterogeneous nucleation is not well understood, but we hypothesize that a possible correlation between binding affinity to a surface and nucleation enhancement might exist. Amorphous polymers have been used in controlling crystallization. However, to our knowledge, no attempt has been made to calculate the free energy of binding of a small molecule to an amorphous polymer in a solvent, and to characterize the binding sites/conformations of this system at a molecular level. We developed a two-step approach, first using Adsorption Locator to identify probable binding sites and molecular dynamics to screen for the best binding sites and then using the Blue-Moon Ensemble method to compute the free energy of binding. A system of ethylene glycol, polyvinyl alcohol (PVA), and heavy water (D(2)O) was used for validation, since experimental data exists on a related system. Looking at four independently constructed surfaces, we found that ethylene glycol binds to an indentation on the surface or in a hole beneath the surface. We focused on the indentation binding sites because they are easily accessible and do not have large free energy barriers. The closest system for which experimental data on binding energetics exists is ethylene glycol on PVA in aqueous solutions/gels, and the magnitudes of the free energy of binding to the three best indentation binding sites are close to the experimental value, 0.4-3.7 kcal/mol higher. Our approach offers a way to compute the free energy of binding and characterize the binding sites/conformations, and is general enough to apply to other small molecule/amorphous polymer/solvent systems.

  4. Energy reduction potential from the shift to electric vehicles: The Flores island case study

    International Nuclear Information System (INIS)

    The increase of fossil fuel demand raises concerns on availability of resources for future energy demand and on potential environmental impacts. Electric vehicles (EVs) appear as one alternative to shift from fossil fuels to renewable energy resources. This research work analyzes the benefits of the introduction of EVs in a small energy system, the Flores island, Azores, in terms of primary energy and CO2 emissions. Four scenarios were designed considering different penetration rates of EVs (Low and High) and different time of recharging strategies (Fixed and Flexible). The high shares of RES in the electricity production system (60–62%) did not guarantee a significant use of RES for the recharging of EVs (10–40%), as the additional electricity required had to be produced mainly from the diesel generators. The flexible recharging strategies allowed doubling the share of RES in the recharging of the EVs when compared to fixed recharging, and consequently double the impact on the reduction of primary energy consumption and fossil fuels imports. While the reduction of primary energy ranged between 0.2% and 1.1%, for CO2 emissions there was a decrease between 0.3 and 1.7%, proving that EVs can help improve the sustainability of energy systems. - highlights: • High shares of RES in electricity do not guarantee a low energy use by EVs. • The introduction of EVs can help reduce CO2 emissions by 11% in 2030. • Flexible time of recharging strategies allows a 2.5 times higher share of RES

  5. Mitigating climate change: Decomposing the relative roles of energy conservation, technological change, and structural shift

    International Nuclear Information System (INIS)

    We decompose the contribution of five drivers of energy use and CO2 emissions reductions in achieving climate change goals over 2005–2100 for various climate policy scenarios. This study contributes to the decomposition literature in three ways. First, it disaggregates drivers of energy demand into technological progress and demand for energy services, represented in terms of useful energy, allowing us to estimate their contributions independently — an improvement over other economy-wide decomposition studies. Secondly, this approach reduces the ambiguity present in many previous measures of structural change. We delineate structural shifts into two separate measures: changes in fuel mix within a given resource or service pathway; and changes in mix among distinct energy resources or end-use services. Finally, this study applies decomposition methods to energy and emission trajectories from two mutually informing perspectives: (i) primary energy resources — crude oil, natural gas, coal, nuclear, and renewables; and (ii) end-uses of energy services — residential and commercial buildings, industry, and transportation. Our results show that technological improvements and energy conservation are important in meeting climate goals in the first half of the coming century; and that nuclear and renewable energy and CCS technology are crucial in meeting more stringent goals in the second half of the century. We examine the relative roles of the drivers in reducing CO2 emissions separately for developed and developing regions. Although the majority of energy and emission growth – and by extension the greatest opportunities for mitigation – will occur in developing countries, the decomposition shows that the relative roles of the five drivers are broadly consistent between these two regions. - Highlights: • We decompose the contribution of five drivers of energy use and CO2 emissions reductions in achieving climate change goals • We analyze differences across

  6. Radiative Energy Shifts of an Atom Coupled to the Derivative of a Scalar Field near a Reflecting Boundary

    Institute of Scientific and Technical Information of China (English)

    LI Cheng-Gai; YU Hong-Wei

    2009-01-01

    We study the radiative energy level shifts of a two-level atom in dipole coupling to the derivative of a massless scalar quantum field in a spacetime with a perfectly reflecting boundary, and calculate the contributions of vacuum fluctuations and radiation reaction to the level shift. It is found that the energy level shift of the excited state is an oscillating function of the atom's distance from the boundary and it can either be positive or negative,while that of the ground state is always positive. The most remarkable feature is that the energy level shift of the ground state behaves like 1/z4 when the atom's distance from the boundary, z, is very large as compared to the transition wavelength of the atom, while it behaves like 1/z3 when z is very small.

  7. Formation Mechanism and Binding Energy for Regular Tetrahedral Structure of Li4

    Institute of Scientific and Technical Information of China (English)

    GOU Qing-Quan; YANG Jian-Hui; LI Ping

    2006-01-01

    The formation mechanism for the regular tetrahedral structure of Li4 cluster is proposed. The curve of the total energy versus the separation R between the two nuclei has been calculated by using the method of Gou's modified arrangement channel quantum mechanics (MACQM). The result shows that the curve has a minimal energy of-29.8279 a.u. at R=14.50 a0. When R approaches infinity the total energy of four lithium atoms has the value of-29.7121 a.u. So the binding energy of Li4 with respect to four lithium atoms is the difference of 0.1158 a.u.for the above two energy values. Therefore the binding energy per atom for Li4 is 0.029 a.u., or 0.7878 eV, which is greater than the binding energy per atom of 0.453 eV for Li2, the binding energy pcr atom of 0.494 eV for Li3 and the binding energy per atom of 0.632 eV for Li5 calculated previously by us. This means that the Li4 cluster may be formed stably in a regular tetrahedral structure of side length R=14.50 a0 with a greater binding energy.

  8. Binding energy referencing for XPS in alkali metal-based battery materials research (I): Basic model investigations

    Energy Technology Data Exchange (ETDEWEB)

    Oswald, S., E-mail: s.oswald@ifw-dresden.de

    2015-10-01

    Highlights: • We point to a not seriously solved conflict in energy scale referencing of Li metal samples in XPS. • Model experiments at Li-, Na-metal and Li-doped HOPG samples were used to classify the effects. • Binding energy shifts up to 3 eV are observed when the alkaline metal is present in metallic state. • A phenomenological explanation based on an electrostatic interaction is suggested. • Consequences for energy scale correction depending on the kind of surface species are followed. - Abstract: For the investigation of chemical changes in Li- and Na-ion battery electrode systems, X-ray photoelectron spectroscopy (XPS) is a well-accepted method. Charge compensation and referencing of the binding energy (BE) scale is necessary to account for the involved mostly non-conducting species. Motivated by a conflict in energy scale referencing of Li-metal samples discussed earlier by several authors, further clarifying experimental results on several Li containing reference materials are presented and extended by similar experiments for Na. When correlating the peak positions of characteristic chemical species in all the different prepared model sample states, there seems to be a systematic deviation in characteristic binding energies of several eV if lithium is present in its metallic state. Similar results were found for sodium. The observations are furthermore confirmed by the implementation of inert artificial energy reference material, such as implanted argon or deposited gold. The behavior is associated with the high reactivity of metallic lithium and a phenomenological explanation is proposed for the understanding of the observations. Consequences for data interpretation in Li-ion battery research will be discussed for various applications in part (II)

  9. Geometry, Energy, and Some Electronic Properties of Carbon Polyprismanes: Ab Initio and Tight-Binding Study

    OpenAIRE

    Konstantin P. Katin; Shostachenko, Stanislav A.; Avkhadieva, Alina I.; Mikhail M. Maslov

    2015-01-01

    We report geometry, energy, and some electronic properties of [n,4]- and [n,5]prismanes (polyprismanes): a special type of carbon nanotubes constructed from dehydrogenated cycloalkane C4- and C5-rings, respectively. Binding energies, interatomic bonds, and the energy gaps between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) have been calculated using density functional approach and nonorthogonal tight-binding model for the systems up to thir...

  10. Implicit ligand theory: Rigorous binding free energies and thermodynamic expectations from molecular docking

    OpenAIRE

    Minh, David D. L.

    2012-01-01

    A rigorous formalism for estimating noncovalent binding free energies and thermodynamic expectations from calculations in which receptor configurations are sampled independently from the ligand is derived. Due to this separation, receptor configurations only need to be sampled once, facilitating the use of binding free energy calculations in virtual screening. Demonstrative calculations on a host-guest system yield good agreement with previous free energy calculations and isothermal titration...

  11. Ultrasensitive Characterization of Mechanical Oscillations and Plasmon Energy Shift in Gold Nanorods.

    Science.gov (United States)

    Soavi, Giancarlo; Tempra, Iacopo; Pantano, Maria F; Cattoni, Andrea; Collin, Stéphane; Biagioni, Paolo; Pugno, Nicola M; Cerullo, Giulio

    2016-02-23

    Mechanical vibrational resonances in metal nanoparticles are intensively studied because they provide insight into nanoscale elasticity and for their potential application to ultrasensitive mass detection. In this paper, we use broadband femtosecond pump-probe spectroscopy to study the longitudinal acoustic phonons of arrays of gold nanorods with different aspect ratios, fabricated by electron beam lithography with very high size uniformity. We follow in real time the impulsively excited extensional oscillations of the nanorods by measuring the transient shift of the localized surface plasmon band. Broadband and high-sensitivity detection of the time-dependent extinction spectra enables one to develop a model that quantitatively describes the periodic variation of the plasmon extinction coefficient starting from the steady-state spectrum with only one additional free parameter. This model allows us to retrieve the time-dependent elongation of the nanorods with an ultrahigh sensitivity and to measure oscillation amplitudes of just a few picometers and plasmon energy shifts on the order of 10(-2) meV. PMID:26767699

  12. Energy Spectrum of YAG:Cr3+ and Thermal Shifts of Its R Lines

    Institute of Scientific and Technical Information of China (English)

    MADong-Ping; CHENJu-Rong

    2005-01-01

    Traditional ligand-field theory has to be improved by taking into account both “pure electronic” contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, R1, R2, R'3 R'2 a, 2, and R1 lines, U band, ground-state zero-field-splitting (GSZFS) and ground-state g factors as well as thermal shifts of R1 line and R2 line of YAG:Cr3+ have been calculated. The results are in very good agreement with the experimental data. In contrast with ruby, the octahedron of ligand oxygen ions surrounding the central Cr3+ ion in YAG:Cr3+ is compressed along the [111] direction. Thus, for YAG:Cr3+ and ruby, the splitting of t23 4 A2 (or t23 2 E) has opposite order, and the trigonal-field parameters of the two crystals have opposite signs. In thermal shifts of R1 and R2 lines of YAG:Cr3+, the temperature-dependent contributions due to EPI are dominant.

  13. Formation Mechanism and Binding Energy for Body-Centred Regular Octahedral Structure of Li7 Cluster

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The formation mechanism for the body-centred regular octahedral structure of Lh cluster is proposed. The curve of the total energy versus the separation R between the nucleus at tie centre and nuclei at the apexes for this structure of Lh has been calculated by using the method of Gou's modified arrangement channel quantum mechanics (MACQM). The result shows that the curve has a minimal energy of-52.169 73 a.u. at R= 5.06a0. When R approaches infinity, the totai energy of seven lithium atoms has the value of -51.996 21 a.u. So the binding energy of Lh with respect to seven lithium atoms is 0.173 52 a.u. Therefore the binding energy per atom for hit is 0.024 79 a.u. or 0.674 eV, which is greater than the binding energy per atom of 0.453 eV for Lii, the binding energy per atom of 0.494 eV for Liz and the binding energy per atom of 0.632 eV for Li& calculated previously by us. This means that the Lh cluster may be formed stably in a body-centred regular octahedral structure with a greater binding energy.

  14. A Prediction Method of Binding Free Energy of Protein and Ligand

    Science.gov (United States)

    Yang, Kun; Wang, Xicheng

    2010-05-01

    Predicting the binding free energy is an important problem in bimolecular simulation. Such prediction would be great benefit in understanding protein functions, and may be useful for computational prediction of ligand binding strengths, e.g., in discovering pharmaceutical drugs. Free energy perturbation (FEP)/thermodynamics integration (TI) is a classical method to explicitly predict free energy. However, this method need plenty of time to collect datum, and that attempts to deal with some simple systems and small changes of molecular structures. Another one for estimating ligand binding affinities is linear interaction energy (LIE) method. This method employs averages of interaction potential energy terms from molecular dynamics simulations or other thermal conformational sampling techniques. Incorporation of systematic deviations from electrostatic linear response, derived from free energy perturbation studies, into the absolute binding free energy expression significantly enhances the accuracy of the approach. However, it also is time-consuming work. In this paper, a new prediction method based on steered molecular dynamics (SMD) with direction optimization is developed to compute binding free energy. Jarzynski's equality is used to derive the PMF or free-energy. The results for two numerical examples are presented, showing that the method has good accuracy and efficiency. The novel method can also simulate whole binding proceeding and give some important structural information about development of new drugs.

  15. Benchmarking ab initio binding energies of hydrogen-bonded molecular clusters based on FTIR spectroscopy

    DEFF Research Database (Denmark)

    Bork, Nicolai Christian; Du, Lin; Reiman, Heidi;

    2014-01-01

    Gibbs free binding energies in molecular complexes and clusters based on gas phase FTIR spectroscopy. The acetonitrile-HCl molecular complex is identified via its redshifted H-Cl stretching vibrational mode. We determine the Gibbs free binding energy, ΔG°295 K, to between 4.8 and 7.9 kJ mol(-1) and......Models of formation and growth of atmospheric aerosols are highly dependent on accurate cluster binding energies. These are most often calculated by ab initio electronic structure methods but remain associated with significant uncertainties. We present a computational benchmarking study of the...

  16. Stable isotope analysis of energy dynamics in aquatic ecosystems suggests trophic shifts following severe wildfire

    Science.gov (United States)

    Martens, A. M.; Silins, U.; Bladon, K. D.; Williams, C.; Wagner, M. J.; Luchkow, E.

    2015-12-01

    Wildfire alters landscapes and can have significant impacts on stream ecosystems. The 2003 Lost Creek wildfire was one of the most severe on Alberta's eastern rocky mountain slopes, resulting in elevated sediment production and nutrient (phosphorus, nitrogen, and carbon) export in impacted streams. These resulted in increased algal productivity and macroinvertebrate abundance and diversity, and as a result, fish in watersheds draining wildfire affected catchments were larger than those in the same age class from reference (unburned) watersheds. In the present investigation, stable isotope analysis of C and N was utilized to evaluate ecosystem energy dynamics and describe trophic relationships in those watersheds. Aquatic invertebrates from burned catchments showed enrichment in δ13C and δ15N relative to algae suggesting a reliance on algae (autochthony) as a primary source of energy. Invertebrates from unburned systems were depleted in δ13C relative to algae indicating reliance on allochthonous or terrestrial primary energy sources. Preliminary analysis of δ15N in macroinvertebrates showed slight enrichment in burned catchments suggesting a trophic shift. More comprehensive macroinvertebrate sampling and identification has been conducted; isotopic analysis will provide greater resolution of how specific families within feeding guilds have been affected by wildfire. This will provide more robust insights into how wildfires may impact stream ecology in mountain environments.

  17. Determination of the Optimal Energy Denominator Shift Parameter of KRb Electronic States in Quantum Chemical Computations Using Perturbation Theory

    Science.gov (United States)

    Shundalau, M. B.; Minko, A. A.

    2016-01-01

    The influence of the energy denominator shift (EDS) parameter and the quantitative and qualitative compositions of electronic states included in CASSCF(2,14)/XMCQDPT2 ab initio calculations of the ground state equilibrium internuclear distance and dissociation energy of polar KRb was determined.

  18. Exciton Binding Energy in Organic-Inorganic Tri-Halide Perovskites.

    Science.gov (United States)

    Askar, Abdelrahman M; Shankar, Karthik

    2016-06-01

    The recent dramatic increase in the power conversion efficiencies of organic-inorganic tri-halide perovskite solar cells has triggered intense research worldwide and created a paradigm shift in the photovoltaics field. It is crucial to develop a solid understanding of the photophysical processes underlying solar cell operation in order to both further improve the photovoltaic performance of perovskite solar cells as well as to exploit the broader optoelectronic applications of the tri-halide perovskites. In this short review, we summarize the main research findings about the binding energy of excitons in tri-halide perovskite materials and find that a value in the range of 2-22 meV at room temperature would be a safe estimate. Spontaneous free carrier generation is the dominant process taking place directly after photoexcitation in organic-inorganic tri-halide perovskites at room temperature, which eliminates the exciton diffusion bottleneck present in organic solar cells and constitutes a major contributing factor to the high photovoltaic performance of this material. PMID:27427650

  19. A climate-change policy induced shift from innovations in carbon-energy production to carbon-energy savings

    International Nuclear Information System (INIS)

    We develop an endogenous growth model with capital, labor and carbon-energy as production factors and three technology variables that measure accumulated innovations for carbon-energy production, carbon-energy savings, and neutral growth. All markets are complete and perfect, except for research, for which we assume that the marginal social benefits exceed the marginal private benefits by factor four. The model constants are calibrated so that the model reproduces the relevant global trends over the 1970-2000 period. The model contains a simple climate module, and is used to assess the impact of Induced Technological Change (ITC) for a policy that aims at a maximum level of atmospheric CO2 concentration (450 ppmv). ITC is shown to reduce the required carbon tax by more than a factor 2, and to reduce costs of such a policy by half. When we do not constrain aggregate R and D expenditures to benchmark levels, costs are further reduced. Numerical simulations show that knowledge accumulation shifts from energy production to energy saving technology. We discuss reasons for differences between our results and earlier results reported in the literature. (author)

  20. Black-body radiation shift of atomic energy-levels:The $ (Z \\alpha)^2\\alpha T^2/m $ correction

    OpenAIRE

    Zhou, Wanping; Mei, Xuesong; Lu, Jingjun; Qiao, Haoxue

    2016-01-01

    The next-to-leading order black-body radiation(BBR) shift to atomic energy-levels, namely $ (Z\\alpha)^2\\alpha T^2/m $ correction, was studied by using the nonrelativistic quantum electrodynamics(NRQED). We also estimate the one-loop contribution of quadrupole and the two-loop contributions of BBR-shift of the thermal(real) photon. These corrections have not been investigated before. The order of magnitude BBR-shift indicates the one-loop contribution of quadrupole is stronger than the previou...

  1. Binding Energy of Molecules on Water Ice: Laboratory Measurements and Modeling

    Science.gov (United States)

    He, Jiao; Acharyya, Kinsuk; Vidali, Gianfranco

    2016-07-01

    We measured the binding energy of N2, CO, O2, CH4, and CO2 on non-porous (compact) amorphous solid water (np-ASW), of N2 and CO on porous ASW, and of NH3 on crystalline water ice. We were able to measure binding energies down to a fraction of 1% of a layer, thus making these measurements more appropriate for astrochemistry than the existing values. We found that CO2 forms clusters on the np-ASW surface even at very low coverages. The binding energies of N2, CO, O2, and CH4 decrease with coverage in the submonolayer regime. Their values at the low coverage limit are much higher than what is commonly used in gas-grain models. An empirical formula was used to describe the coverage dependence of the binding energies. We used the newly determined binding energy distributions in a simulation of gas-grain chemistry for cold cloud and hot-core models. We found that owing to the higher value of binding energy in the submonolayer regime, a fraction of all these ices remains for much longer and up to higher temperatures on the grain surface compared to the single value energies currently used in the astrochemical models.

  2. Distributed energy resources management using plug-in hybrid electric vehicles as a fuel-shifting demand response resource

    International Nuclear Information System (INIS)

    Highlights: • Definition fuel shifting demand response programs applied to the electric vehicles. • Integration of the proposed fuel shifting in energy resource management algorithm. • Analysis of fuel shifting contribution to support the consumption increasing. • Analysis of fuel shifting contribution to support the electric vehicles growing. • Sensitivity analysis considering different electric vehicles penetration levels. - Abstract: In the smart grids context, distributed energy resources management plays an important role in the power systems’ operation. Battery electric vehicles and plug-in hybrid electric vehicles should be important resources in the future distribution networks operation. Therefore, it is important to develop adequate methodologies to schedule the electric vehicles’ charge and discharge processes, avoiding network congestions and providing ancillary services. This paper proposes the participation of plug-in hybrid electric vehicles in fuel shifting demand response programs. Two services are proposed, namely the fuel shifting and the fuel discharging. The fuel shifting program consists in replacing the electric energy by fossil fuels in plug-in hybrid electric vehicles daily trips, and the fuel discharge program consists in use of their internal combustion engine to generate electricity injecting into the network. These programs are included in an energy resources management algorithm which integrates the management of other resources. The paper presents a case study considering a 37-bus distribution network with 25 distributed generators, 1908 consumers, and 2430 plug-in vehicles. Two scenarios are tested, namely a scenario with high photovoltaic generation, and a scenario without photovoltaic generation. A sensitivity analyses is performed in order to evaluate when each energy resource is required

  3. Calculations of the Triton Binding Energy with a Lorentz Boosted Nucleon-Nucleon Potential

    Directory of Open Access Journals (Sweden)

    Elster Ch.

    2010-04-01

    Full Text Available We study the binding energy of the three-nucleon system in relativistic models that use two different relativistic treatments of the potential that are phase equivalent to realistic NN interactions. One is based on a unitary scale transformation that relates the non-relativistic center-of-mass Hamiltonian to the relativistic mass (rest energy operator and the other uses a non-linear equation that relates the interaction in the relativistic mass operator to the non-relativistic interaction. In both cases Lorentz-boosted interactions are used in the relativistic Faddeev equation to solve for the three-nucleon binding energy. Using the same realistic NN potentials as input, the solution of the relativistic three-nucleon Faddeev equation for 3H shows slightly less binding energy than the corresponding nonrelativistic result. The effect of the Wigner spin rotation on the binding is very small.

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

    Science.gov (United States)

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

    2007-10-01

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

  5. Formation Mechanism and Binding Energy for Body-Centred Regular Tetrahedral Structure of Li5

    Institute of Scientific and Technical Information of China (English)

    LI Ping; YANG Jian-Hui; GOU Qing-Quan

    2006-01-01

    The formation mechanism for the body-centred regular tetrahedral structure of Li5 cluster is proposed.The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes for this structure of Li5 has been calculated by using the method of Gou's modified arrangement channel quantum mechanics(MACQM). The result shows that the curve has a minimal energy of-37.2562 a.u. at R = 14.5a0. When R approaches infinity the total energy of five lithium atoms has the value of-37.1401 a.u. So the binding energy of Li5 with respect to five lithium atoms is the difference of 0.1161 a.u. for the above two energy values. Therefore the binding energy per atom for Li5 is 0.023 22 a.u., or 0.632 eV, which is greater than the binding energy per atom of 0.453 eV for Li2 and the binding energy per atom of 0.494 eV for Li3 calculated previously by us. This means that the Li5 cluster may be formed stably in a body-centred regular tetrahedral structure with a greater binding energy.

  6. EVA space suit proton and electron threshold energy measurements by XCT and range shifting

    Energy Technology Data Exchange (ETDEWEB)

    Moyers, M.F. [Department of Radiation Medicine, Loma Linda University, 11234 Anderson St., Loma Linda, California 92354 (United States)]. E-mail: MFMoyers@adelphia.net; Saganti, P.B. [Space Radiation Health Project, NASA-Johnson Space Center, 2101 NASA Road 1, Houston, Texas 77058 (United States); Department of Physics and NASA-Center for Applied Radiation Research, Prairie View A and M University, Prairie View, Texas 77446 (United States); Nelson, G.A. [Department of Radiation Medicine, Loma Linda University, 11234 Anderson St., Loma Linda, California 92354 (United States)

    2006-10-15

    Construction of the International Space Station (ISS) will require more than 1000 h of extravehicular activity (EVA). Outside of the ISS during EVA, astronauts and cosmonauts are likely to be exposed to a large fluence of electrons and protons. Development of radiation protection guidelines and mitigation of risks requires the determination of the minimum energy of electrons and protons that penetrate the astronaut EVA suits at various locations. Measurements of the water equivalent thickness of both United States (US) and Russian EVA suits were obtained by performing X-ray computed tomography (XCT) scans. Selected regions of interest of the suits were further evaluated using a 'differential range shift' technique. This technique involved measuring thickness ionization curves for 6 MeV electron and 155 MeV proton beams with ionization chambers using a constant source-to-detector distance. The thicknesses were obtained by stacking polystyrene slabs immediately upstream of the detector. The thicknesses of the 50% ionizations relative to the maximum ionizations were determined. The detectors were then placed within the suit and the stack thickness adjusted until the 50% ionization was re-established. The difference in thickness between the 50% thicknesses was then used with standard range tables to determine the threshold energy for penetration. This paper provides a detailed description of the experimental arrangement and the obtained results.

  7. EVA space suit proton and electron threshold energy measurements by XCT and range shifting

    International Nuclear Information System (INIS)

    Construction of the International Space Station (ISS) will require more than 1000 h of extravehicular activity (EVA). Outside of the ISS during EVA, astronauts and cosmonauts are likely to be exposed to a large fluence of electrons and protons. Development of radiation protection guidelines and mitigation of risks requires the determination of the minimum energy of electrons and protons that penetrate the astronaut EVA suits at various locations. Measurements of the water equivalent thickness of both United States (US) and Russian EVA suits were obtained by performing X-ray computed tomography (XCT) scans. Selected regions of interest of the suits were further evaluated using a 'differential range shift' technique. This technique involved measuring thickness ionization curves for 6 MeV electron and 155 MeV proton beams with ionization chambers using a constant source-to-detector distance. The thicknesses were obtained by stacking polystyrene slabs immediately upstream of the detector. The thicknesses of the 50% ionizations relative to the maximum ionizations were determined. The detectors were then placed within the suit and the stack thickness adjusted until the 50% ionization was re-established. The difference in thickness between the 50% thicknesses was then used with standard range tables to determine the threshold energy for penetration. This paper provides a detailed description of the experimental arrangement and the obtained results

  8. Public Opinion shifts to the favour of nuclear energy due to steam generator transport

    International Nuclear Information System (INIS)

    In late August and early September of 1999, nuclear energy topics occupied a central place in the Slovenian media because of the transport of two new steam generators to the Krsko nuclear power plant, and also due to the protest action of an Austrian Green peace group. Before these events, the public opinion in Slovenia was not in favour or nuclear energy ;and Green peace had a good reputation. In September it has lost much credibility because of their clumsy :action of protest, and in just one month this caused a shift of public opinion in Slovenia towards support of Slovenian's only nuclear power plant. The Green peace protest action occurred during the transport of the two new steam generators to Krsko. By replacement of the old steam generators the operation of the Krsko NPP will be extended until 2023. The transport envoy travelled during the first half of September '99 across a considerable part of Slovene territory, passing by the capital of Ljubljana. (authors)

  9. A general scheme for the estimation of oxygen binding energies on binary transition metal surface alloys

    DEFF Research Database (Denmark)

    Greeley, Jeffrey Philip; Nørskov, Jens Kehlet

    2005-01-01

    A simple scheme for the estimation of oxygen binding energies on transition metal surface alloys is presented. It is shown that a d-band center model of the alloy surfaces is a convenient and appropriate basis for this scheme; variations in chemical composition, strain effects, and ligand effects...... for the estimation of oxygen binding energies on a wide variety of transition metal alloys. (c) 2005 Elsevier B.V. All rights reserved....

  10. Effect of a high intensity laser beam on impurity binding energy in a nanocone

    Science.gov (United States)

    Paredes, H.; Beltrán Ríos, C. L.; Gutíerrez, W.

    2016-02-01

    This paper presents theoretical results of a study that analyzed the effect of a high- frequency laser in the ground state binding energy of a hydrogenic donnor impurity. For these results, the trigonometric sweep method and framework of the effective mass approximation is applied. The results showed that the binding energy changes depending on the laser intensity and the impurity position across of the nanocone axis. The results agree with previous results obtained in similar systems.

  11. Prediction of SAMPL3 Host-Guest Affinities with the Binding Energy Distribution Analysis Method (BEDAM)

    OpenAIRE

    Gallicchio, Emilio; Ronald M Levy

    2012-01-01

    BEDAM calculations are described to predict the free energies of binding of a series of anaesthetic drugs to a recently characterized acyclic cucurbituril host. The modeling predictions, conducted as part of the SAMPL3 host-guest affinity blind challenge, are generally in good quantitative agreement with the experimental measurements. The correlation coefficient between computed and measured binding free energies is 70% with high statistical significance. Multiple conformational stereoisomers...

  12. Calculation of Host-Guest Binding Affinities Using a Quantum-Mechanical Energy Model

    OpenAIRE

    Muddana, Hari S.; Gilson, Michael K.

    2012-01-01

    The prediction of protein-ligand binding affinities is of central interest in computer-aided drug discovery, but it is still difficult to achieve a high degree of accuracy. Recent studies suggesting that available force fields may be a key source of error motivate the present study, which reports the first mining minima (M2) binding affinity calculations based on a quantum mechanical energy model, rather than an empirical force field. We apply a semi-empirical quantum-mechanical energy functi...

  13. Condensation on surface energy gradient shifts drop size distribution toward small drops.

    Science.gov (United States)

    Macner, Ashley M; Daniel, Susan; Steen, Paul H

    2014-02-25

    During dropwise condensation from vapor onto a cooled surface, distributions of drops evolve by nucleation, growth, and coalescence. Drop surface coverage dictates the heat transfer characteristics and depends on both drop size and number of drops present on the surface at any given time. Thus, manipulating drop distributions is crucial to maximizing heat transfer. On earth, manipulation is achieved with gravity. However, in applications with small length scales or in low gravity environments, other methods of removal, such as a surface energy gradient, are required. This study examines how chemical modification of a cooled surface affects drop growth and coalescence, which in turn influences how a population of drops evolves. Steam is condensed onto a horizontally oriented surface that has been treated by silanization to deliver either a spatially uniform contact angle (hydrophilic, hydrophobic) or a continuous radial gradient of contact angles (hydrophobic to hydrophilic). The time evolution of number density and associated drop size distributions are measured. For a uniform surface, the shape of the drop size distribution is unique and can be used to identify the progress of condensation. In contrast, the drop size distribution for a gradient surface, relative to a uniform surface, shifts toward a population of small drops. The frequent sweeping of drops truncates maturation of the first generation of large drops and locks the distribution shape at the initial distribution. The absence of a shape change indicates that dropwise condensation has reached a steady state. Previous reports of heat transfer enhancement on chemical gradient surfaces can be explained by this shift toward smaller drops, from which the high heat transfer coefficients in dropwise condensation are attributed to. Terrestrial applications using gravity as the primary removal mechanism also stand to benefit from inclusion of gradient surfaces because the critical threshold size required for

  14. Tough Shift

    DEFF Research Database (Denmark)

    Brewer, Robert S.; Verdezoto, Nervo; Holst, Thomas;

    2015-01-01

    people to change their behavior at home. Leveraging prior research on encouraging reductions in residential energy use through game play, we introduce ShareBuddy: a casual mobile game intended to encourage players not only to reduce, but also to shift their electricity use. We conducted two field studies...... real-world resource use into a game....

  15. Ion Binding Energies Determining Functional Transport of ClC Proteins

    Science.gov (United States)

    Yu, Tao; Guo, Xu; Zou, Xian-Wu; Sang, Jian-Ping

    2014-06-01

    The ClC-type proteins, a large family of chloride transport proteins ubiquitously expressed in biological organisms, have been extensively studied for decades. Biological function of ClC proteins can be reflected by analyzing the binding situation of Cl- ions. We investigate ion binding properties of ClC-ec1 protein with the atomic molecular dynamics simulation approach. The calculated electrostatic binding energy results indicate that Cl- at the central binding site Scen has more binding stability than the internal binding site Sint. Quantitative comparison between the latest experimental heat release data isothermal titration calorimetry (ITC) and our calculated results demonstrates that chloride ions prefer to bind at Scen than Sint in the wild-type ClC-ec1 structure and prefer to bind at Sext and Scen than Sint in mutant E148A/E148Q structures. Even though the chloride ions make less contribution to heat release when binding to Sint and are relatively unstable in the Cl- pathway, they are still part contributors for the Cl- functional transport. This work provides a guide rule to estimate the importance of Cl- at the binding sites and how chloride ions have influences on the function of ClC proteins.

  16. Quantum Monte Carlo calculation of the binding energy of the beryllium dimer

    Energy Technology Data Exchange (ETDEWEB)

    Deible, Michael J.; Kessler, Melody; Gasperich, Kevin E.; Jordan, Kenneth D. [Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)

    2015-08-28

    The accurate calculation of the binding energy of the beryllium dimer is a challenging theoretical problem. In this study, the binding energy of Be{sub 2} is calculated using the diffusion Monte Carlo (DMC) method, using single Slater determinant and multiconfigurational trial functions. DMC calculations using single-determinant trial wave functions of orbitals obtained from density functional theory calculations overestimate the binding energy, while DMC calculations using Hartree-Fock or CAS(4,8), complete active space trial functions significantly underestimate the binding energy. In order to obtain an accurate value of the binding energy of Be{sub 2} from DMC calculations, it is necessary to employ trial functions that include excitations outside the valence space. Our best estimate DMC result for the binding energy of Be{sub 2}, obtained by using configuration interaction trial functions and extrapolating in the threshold for the configurations retained in the trial function, is 908 cm{sup −1}, only slightly below the 935 cm{sup −1} value derived from experiment.

  17. Smart grids: A paradigm shift on energy generation and distribution with the emergence of a new energy management business model

    Science.gov (United States)

    Cardenas, Jesus Alvaro

    An energy and environmental crisis will emerge throughout the world if we continue with our current practices of generation and distribution of electricity. A possible solution to this problem is based on the Smart grid concept, which is heavily influenced by Information and Communication Technology (ICT). Although the electricity industry is mostly regulated, there are global models used as roadmaps for Smart Grids' implementation focusing on technologies and the basic generation-distribution-transmission model. This project aims to further enhance a business model for a future global deployment. It takes into consideration the many factors interacting in this energy provision process, based on the diffusion of technologies and literature surveys on the available documents in the Internet as well as peer-reviewed publications. Tariffs and regulations, distributed energy generation, integration of service providers, consumers becoming producers, self-healing devices, and many other elements are shifting this industry into a major change towards liberalization and deregulation of this sector, which has been heavily protected by the government due to the importance of electricity for consumers. We propose an Energy Management Business Model composed by four basic elements: Supply Chain, Information and Communication Technology (ICT), Stakeholders Response, and the resulting Green Efficient Energy (GEE). We support the developed model based on the literature survey, we support it with the diffusion analysis of these elements, and support the overall model with two surveys: one for peers and professionals, and other for experts in the field, based on the Smart Grid Carnegie Melon Maturity Model (CMU SEI SGMM). The contribution of this model is a simple path to follow for entities that want to achieve environmental friendly energy with the involvement of technology and all stakeholders.

  18. Study of quark mass dependence of binding energy for light nuclei in 2+1 flavor lattice QCD

    CERN Document Server

    Yamazaki, Takeshi; Kuramashi, Yoshinobu; Ukawa, Akira

    2015-01-01

    We investigate the formation of light nuclei with the nuclear mass number less than or equal to four in 2+1 flavor QCD using a non-perturbative improved Wilson quark and Iwasaki gauge actions. The quark mass is decreased from our previous work to the one corresponding to the pion mass of 0.30 GeV. In each multi-nucleon channel, the energy shift of the ground state relative to the assembly of free nucleons is calculated on two volumes, whose spatial extents are 4.3 fm and 5.8 fm. From the volume dependence of the energy shift, we distinguish a bound state of multi nucleons from an attractive scattering state. We find that all the ground states measured in this calculation are bound states. As in the previous studies at larger $m_\\pi$, our result indicates that at $m_\\pi = 0.30$ GeV the effective interaction between nucleons in the light nuclei is relatively stronger than the one in nature, since the results for the binding energies are larger than the experimental values and a bound state appears in the dineut...

  19. Legislative fractionalization and partisan shifts to the left increase the volatility of public energy R and D expenditures

    International Nuclear Information System (INIS)

    This article shows that legislative fractionalization and leftward (but not rightward) partisan shifts increase the volatility of public R and D expenditures in new energy technologies. We develop a highly accurate estimator for public energy R and D expenditures, and examine deviations from the estimated values using data for member states of the International Energy Agency, 1981–2007. Given that unpredictable fluctuation in public spending on new energy technology reduces the positive effect of such spending on innovation, our empirical analyses imply that countries with fractionalized legislatures can improve the performance of their energy technology programs by enacting institutional mechanisms that reduce the volatility of public spending. Similarly, the results indicate that left-wing and right-wing governments can improve the performance of public technology programs through agreements that distribute gains in such a fashion that partisan shifts do not cause spending cuts. Contravening the conventional wisdom, we also find that public energy R and D is unusually stable in the United States. - Highlights: ► Legislative fractionalization increases the volatility of public energy R and D. ► Partisan shifts to the left increase the volatility of public energy R and D. ► The article develops a method for estimating the volatility of energy policy.

  20. SAAMBE: Webserver to Predict the Charge of Binding Free Energy Caused by Amino Acids Mutations

    Directory of Open Access Journals (Sweden)

    Marharyta Petukh

    2016-04-01

    Full Text Available Predicting the effect of amino acid substitutions on protein–protein affinity (typically evaluated via the change of protein binding free energy is important for both understanding the disease-causing mechanism of missense mutations and guiding protein engineering. In addition, researchers are also interested in understanding which energy components are mostly affected by the mutation and how the mutation affects the overall structure of the corresponding protein. Here we report a webserver, the Single Amino Acid Mutation based change in Binding free Energy (SAAMBE webserver, which addresses the demand for tools for predicting the change of protein binding free energy. SAAMBE is an easy to use webserver, which only requires that a coordinate file be inputted and the user is provided with various, but easy to navigate, options. The user specifies the mutation position, wild type residue and type of mutation to be made. The server predicts the binding free energy change, the changes of the corresponding energy components and provides the energy minimized 3D structure of the wild type and mutant proteins for download. The SAAMBE protocol performance was tested by benchmarking the predictions against over 1300 experimentally determined changes of binding free energy and a Pearson correlation coefficient of 0.62 was obtained. How the predictions can be used for discriminating disease-causing from harmless mutations is discussed. The webserver can be accessed via http://compbio.clemson.edu/saambe_webserver/.

  1. Formation Mechanism and Binding Energy for Regular Octahedral Structure of Li6 Cluster

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yan-Ping; LI Ping; GOU Qing-Quan; LIU Wei-Na

    2008-01-01

    The formation mechanism for the regular octahedral structure of Li6cluster is proposed. The curve of the total energy versus the separation R between any two neighboring nuclei has been calculated by using the method of Gou's modified arrangement channel quantum mechanics (MACQM). The result shows that the curve has a minimal energy of-44.736 89 a.u. At R=5.07α0. When R approaches infinity, the total energy of six lithium atoms has the value of-44.568 17 a.u. So the binding energy of Li6 with respect to six lithium atoms is 0.1687 a.u. Therefore, the binding energy per atom for Li6 is 0.028 12 a.u., or 0.7637 eV, which is greater than the binding energy per atom of 0.453 eV for Li2 arid the binding energy per atom of 0.494 eV for Li3 calculated in our previous work. This means that the Li6 cluster may be formed in a regular octahedral structure with a greater binding energy.

  2. Pressure-Induced Shifts of Energy Spectra of α-Al2O3:Mn4+

    Institute of Scientific and Technical Information of China (English)

    MA Dong-Ping,; CHEN Ju-Rong; MA Ning

    2002-01-01

    By making use of the diagonalization of the complete d3 energy matrix in a trigonally distorted cubic-field and the theory of pressure-induced shifts (PS) of energy spectra, the whole energy spectrum of α-Al2 O3 :Mn4+ and PS of levels have been calculated. All the calculated results are in excellent agreement with the experimental data. The comparison between the results ofα-AlO3:Mn4+ and ruby has been made. It is found that on one hand, R1-line and R2line PS of α-Al2O3:Mn4+ and ruby are linear in pressure over 0 ~ 100 kbar, and their values of the principal parameter for PS are very close to each other. On the other hand, the sensitivities of R1-line and R2-line PS of α-Al2O3:Mn4+are higher than those of ruby respectively, which comes mainly from the difference between the values of parameters at normal pressure of two crystals; moreover, the expansion ofd-electron wavefunctions of α-Al2 O3 :Mn4+ with compression is slightly larger than the one of ruby, and the effective charge experienced by d-electrons of α-Al2O3:Mn4+ decreases with compression more rapidly than the one of ruby. In the final analysis, all these can be explained in terms of the facts that the two crystals are doped α-Al2O3 with two isoelectronic ions; the strengths of the crystal field and covalency of α-Al2O3 :Mn4+ are larger than those of ruby respectively, due to the charge of Mn4+ to be larger than that of Cr3+.

  3. Shifts in the myosin heavy chain isozymes in the mouse heart result in increased energy efficiency

    Science.gov (United States)

    Hoyer, Kirsten; Krenz, Maike; Robbins, Jeffrey; Ingwall, Joanne S.

    2007-01-01

    Cardiac-specific transgenesis in the mouse is widely used to study the basic biology and chemistry of the heart and to model human cardiovascular disease. A fundamental difference between mouse and human hearts is the background motor protein: mouse hearts contain predominantly the αα-myosin heavy chain (MyHC) isozyme while human hearts contain predominantly the ββ-MyHC isozyme. Although the intrinsic differences in mechanical and enzymatic properties of the αα- and ββ-MyHC molecules are well known, the consequences of isozyme shifts on energetic of the intact beating heart remain unknown. Therefore, we compared the free energy of ATP hydrolysis (|ΔG~ATP|) determined by 31P NMR spectroscopy in isolated perfused littermate mouse hearts containing the same amount of myosin comprised of either >95% αα-MyHC or ~83% ββ-MyHC. |ΔG~ATP| was ~2 kJ mol−1 higher in the ββ-MyHC hearts at all workloads. Furthermore, upon inotropic challenge, hearts containing predominantly ββ-MyHC hearts increased developed pressure more than αα-MyHC hearts whereas heart rate increased more in αα-MyHC hearts. Thus, hearts containing predominantly the ββ-MyHC isozyme are more energy efficient than αα-MyHC hearts. We suggest that these fundamental differences in the motor protein energy efficiency at the whole heart level should be considered when interpreting results using mouse-based cardiovascular modeling of normal and diseased human heart. PMID:17054980

  4. An encodable lanthanide binding tag with reduced size and flexibility for measuring residual dipolar couplings and pseudocontact shifts in large proteins

    Energy Technology Data Exchange (ETDEWEB)

    Barb, Adam W., E-mail: abarb@iastate.edu; Subedi, Ganesh P. [Iowa State University, Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology (United States)

    2016-01-15

    Metal ions serve important roles in structural biology applications from long-range perturbations seen in magnetic resonance experiments to electron-dense signatures in X-ray crystallography data; however, the metal ion must be secured in a molecular framework to achieve the maximum benefit. Polypeptide-based lanthanide-binding tags (LBTs) represent one option that can be directly encoded within a recombinant protein expression construct. However, LBTs often exhibit significant mobility relative to the target molecule. Here we report the characterization of improved LBTs sequences for insertion into a protein loop. These LBTs were inserted to connect two parallel alpha helices of an immunoglobulin G (IgG)-binding Z domain platform. Variants A and B bound Tb{sup 3+} with high affinity (0.70 and 0.13 μM, respectively) and displayed restricted LBT motion. Compared to the parent construct, the metal-bound A experienced a 2.5-fold reduction in tag motion as measured by magnetic field-induced residual dipolar couplings and was further studied in a 72.2 kDa complex with the human IgG1 fragment crystallizable (IgG1 Fc) glycoprotein. The appearance of both pseudo-contact shifts (−0.221 to 0.081 ppm) and residual dipolar couplings (−7.6 to 14.3 Hz) of IgG1 Fc resonances in the IgG1 Fc:(variant A:Tb{sup 3+}){sub 2} complex indicated structural restriction of the LBT with respect to the Fc. These studies highlight the applicability of improved LBT sequences with reduced mobility to probe the structure of macromolecular systems.

  5. An encodable lanthanide binding tag with reduced size and flexibility for measuring residual dipolar couplings and pseudocontact shifts in large proteins.

    Science.gov (United States)

    Barb, Adam W; Subedi, Ganesh P

    2016-01-01

    Metal ions serve important roles in structural biology applications from long-range perturbations seen in magnetic resonance experiments to electron-dense signatures in X-ray crystallography data; however, the metal ion must be secured in a molecular framework to achieve the maximum benefit. Polypeptide-based lanthanide-binding tags (LBTs) represent one option that can be directly encoded within a recombinant protein expression construct. However, LBTs often exhibit significant mobility relative to the target molecule. Here we report the characterization of improved LBTs sequences for insertion into a protein loop. These LBTs were inserted to connect two parallel alpha helices of an immunoglobulin G (IgG)-binding Z domain platform. Variants A and B bound Tb(3+) with high affinity (0.70 and 0.13 μM, respectively) and displayed restricted LBT motion. Compared to the parent construct, the metal-bound A experienced a 2.5-fold reduction in tag motion as measured by magnetic field-induced residual dipolar couplings and was further studied in a 72.2 kDa complex with the human IgG1 fragment crystallizable (IgG1 Fc) glycoprotein. The appearance of both pseudo-contact shifts (-0.221 to 0.081 ppm) and residual dipolar couplings (-7.6 to 14.3 Hz) of IgG1 Fc resonances in the IgG1 Fc:(variant A:Tb(3+))2 complex indicated structural restriction of the LBT with respect to the Fc. These studies highlight the applicability of improved LBT sequences with reduced mobility to probe the structure of macromolecular systems. PMID:26728077

  6. An encodable lanthanide binding tag with reduced size and flexibility for measuring residual dipolar couplings and pseudocontact shifts in large proteins

    International Nuclear Information System (INIS)

    Metal ions serve important roles in structural biology applications from long-range perturbations seen in magnetic resonance experiments to electron-dense signatures in X-ray crystallography data; however, the metal ion must be secured in a molecular framework to achieve the maximum benefit. Polypeptide-based lanthanide-binding tags (LBTs) represent one option that can be directly encoded within a recombinant protein expression construct. However, LBTs often exhibit significant mobility relative to the target molecule. Here we report the characterization of improved LBTs sequences for insertion into a protein loop. These LBTs were inserted to connect two parallel alpha helices of an immunoglobulin G (IgG)-binding Z domain platform. Variants A and B bound Tb3+ with high affinity (0.70 and 0.13 μM, respectively) and displayed restricted LBT motion. Compared to the parent construct, the metal-bound A experienced a 2.5-fold reduction in tag motion as measured by magnetic field-induced residual dipolar couplings and was further studied in a 72.2 kDa complex with the human IgG1 fragment crystallizable (IgG1 Fc) glycoprotein. The appearance of both pseudo-contact shifts (−0.221 to 0.081 ppm) and residual dipolar couplings (−7.6 to 14.3 Hz) of IgG1 Fc resonances in the IgG1 Fc:(variant A:Tb3+)2 complex indicated structural restriction of the LBT with respect to the Fc. These studies highlight the applicability of improved LBT sequences with reduced mobility to probe the structure of macromolecular systems

  7. Accurate determination of the binding energy of the formic acid dimer: The importance of geometry relaxation

    Science.gov (United States)

    Kalescky, Robert; Kraka, Elfi; Cremer, Dieter

    2014-02-01

    The formic acid dimer in its C2h-symmetrical cyclic form is stabilized by two equivalent H-bonds. The currently accepted interaction energy is 18.75 kcal/mol whereas the experimental binding energy D0 value is only 14.22 ±0.12 kcal/mol [F. Kollipost, R. W. Larsen, A. V. Domanskaya, M. Nörenberg, and M. A. Suhm, J. Chem. Phys. 136, 151101 (2012)]. Calculation of the binding energies De and D0 at the CCSD(T) (Coupled Cluster with Single and Double excitations and perturbative Triple excitations)/CBS (Complete Basis Set) level of theory, utilizing CCSD(T)/CBS geometries and the frequencies of the dimer and monomer, reveals that there is a 3.2 kcal/mol difference between interaction energy and binding energy De, which results from (i) not relaxing the geometry of the monomers upon dissociation of the dimer and (ii) approximating CCSD(T) correlation effects with MP2. The most accurate CCSD(T)/CBS values obtained in this work are De = 15.55 and D0 = 14.32 kcal/mol where the latter binding energy differs from the experimental value by 0.1 kcal/mol. The necessity of employing augmented VQZ and VPZ calculations and relaxing monomer geometries of H-bonded complexes upon dissociation to obtain reliable binding energies is emphasized.

  8. Interfacial energy level shifts in few-molecule clusters of the organic semiconductor PTCDA

    Science.gov (United States)

    Burke, Sarah; Cochrane, Katherine; Schiffrin, Agustin; Roussy, Tanya

    2014-03-01

    Detailed knowledge of the local electronic structure of organic semiconductors near interfaces is crucial for the understanding of a variety of electronic and optoelectronic applications of these emerging materials. However, organic molecules are highly sensitive to the local environment, which abruptly changes at an interface. Here, we present a study on the prototypical organic semiconductor PTCDA by scanning tunneling microscopy and spectroscopic mapping. Nanoscale clusters of varying size and geometry were probed on a bilayer NaCl film on Ag(111). The molecular states, while decoupled from the underlying metal surface, are relatively delocalized within these monolayer islands. Depending on the size of the cluster and arrangement of molecules within the cluster, edge molecules exhibit varying energy level shifts relative to the central molecules, both of which differ from the isolated molecule. For well ordered islands, this leads to a type-1 heterojunction, with a larger band gap at the edge of the cluster differing by as much as 0.5eV. In considering nanoscale structures within multicomponent device architectures, such internal heterostructures established by differences in the local environment are an important consideration, and could even be exploited.

  9. NMR chemical shift as analytical derivative of the Helmholtz free energy

    CERN Document Server

    Heuvel, Willem Van den

    2012-01-01

    We present a theory for the temperature-dependent nuclear magnetic shielding tensor of molecules with arbitrary electronic structure. The theory is a generalization of Ramsey's theory for closed-shell molecules. The shielding tensor is defined as a second derivative of the Helmholtz free energy of the electron system in equilibrium with the applied magnetic field and the nuclear magnetic moments. This derivative is analytically evaluated and expressed as a sum over states formula. Special consideration is given to a system with an isolated degenerate ground state for which the size of the degeneracy and the composition of the wave functions are arbitrary. In this case the paramagnetic part of the shielding tensor is expressed in terms of the $g$ and $A$ tensors of the EPR spin Hamiltonian of the degenerate state. As an illustration of the proposed theory, we provide an explicit formula for the paramagnetic shift of the central lanthanide ion in endofullerenes Ln@C$_{60}$, with Ln=Ce$^{3+}$, Nd$^{3+}$, Sm$^{3+...

  10. Distributed energy resources management using plug-in hybrid electric vehicles as a fuel-shifting demand response resource

    DEFF Research Database (Denmark)

    Morais, Hugo; Sousa, Tiago; Soares, J.;

    2015-01-01

    In the smart grids context, distributed energy resources management plays an important role in the power systems' operation. Battery electric vehicles and plug-in hybrid electric vehicles should be important resources in the future distribution networks operation. Therefore, it is important......, namely the fuel shifting and the fuel discharging. The fuel shifting program consists in replacing the electric energy by fossil fuels in plug-in hybrid electric vehicles daily trips, and the fuel discharge program consists in use of their internal combustion engine to generate electricity injecting...... to develop adequate methodologies to schedule the electric vehicles' charge and discharge processes, avoiding network congestions and providing ancillary services.This paper proposes the participation of plug-in hybrid electric vehicles in fuel shifting demand response programs. Two services are proposed...

  11. Formation Mechanism and Binding Energy for Equilateral Triangle Structure of Li3 Cluster

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The formation mechanism for the equilateral triangle structure of Li3 cluster is proposed. The curve of the total energy versus the interatomic distance for this structure has been calculated by using the method of Gou's Modified Arrangement Channel Quantum Mechanics. The result shows that the curve has a minimal energy of-22.338 60 a.u at R = 5.82 a0. The total energy of Li3 when R approaches ∞ has the value of-22.284 09 a.u. This is also the total energy of three lithium atoms dissociated from Li3. The difference value of 0.0545 08 a.u. for the above two energy values is the dissociation energy of Li3 cluster, which is also its binding energy. Therefore the binding energy per lithium atom for Li3 is 0.018 169 a.u. = 0.494 eV, which is greater than the binding energy of 0.453 eV per atom for Li2 calculated in a previous work. This means that the Li3 cluster may be formed in the equilateral triangle structure of side length R = 5.82a0 stably with a stronger binding from the symmetrical interaction among the three lithium atoms.

  12. Modal shifts in short-haul passenger travel and the consequent energy impacts. [Intercity travel under 500 miles

    Energy Technology Data Exchange (ETDEWEB)

    1980-03-01

    A study was performed to evaluate the impacts of strategies to effect modal shifts in short-haul passenger travel (defined herein as intercity travel under 500 miles) from energy-intensive modes to those modes that are less energy-intensive. A series of individual strategies, ranging from incentives to the less energy-intensive modes (bus, rail) to penalties to the more energy-intensive modes (auto, air) was examined to determine energy saved and policy implications relative to strategy implementation. The most effective of the individual strategies were then combined in all permutations, and the analysis was repeated. As part of the analytical process, effects of factors other than energy (user cost and time, emissions, government subsidy, and travel fatailities) were examined in a benefit/cost analysis. Finally, energy savings, benefit/cost impacts, implementation considerations, and policy implications were evaluated to arrive at conclusions as to the effectiveness of the more-influential strategies and to the overall effectiveness of induced modal shifts. The principal conclusion of the study is that the maximum 1980 energy saving that might be realized by modal shifts, discounting the concurrent effects of demand suppression and improvement of mode efficiency, is approximately 83 x 10/sup 12/ Btu (46,500 bbl gasoline per day), 3.8% of the total projected 1980 energy consumption in the short-haul transportation sector and 0.23% of the total US petroleum use. It was also concluded that strategies to achieve these small savings by modal shifts would result in significant economic, social, and business disruptions.

  13. Sector-based political analysis of energy transition: Green shift in the forest policy regime in France

    International Nuclear Information System (INIS)

    This article examines energy transition political process from a sector-based approach, through the analysis of recent shift in the French forest policy regime. We demonstrate that, since 2007, energy transition policies have led to a harvesting turn within the French forest policy framework, meaning that priority is given to wood mobilisation, mainly for biomass uses. In addition, our findings suggest that the political authority wielded by the state over forest policy has shifted from forest administrative services to energy agencies and local authorities. Finally, we show that, although implementation of the harvesting turn is a cause of sectoral and inter-sectoral tensions, energy transition challenge also contributes to a process of (re)institutionalisation of mediation relationships among forestry stakeholders and wood-based industries representatives. The article concludes by arguing that sectors should retain relevant institutional frameworks for actors when choosing political arrangements required for implementing energy transition policy. - Highlights: • Implementing energy transition policy potentially challenges sector-based politics. • We propose a policy regime framework and socio-political investigations. • We analyse the political impact of energy transition policy on French forest sector. • Shifts occur in sectoral policy framework, authority, and mediation relationships

  14. Binding energies of nucleobase complexes: Relevance to homology recognition of DNA

    Science.gov (United States)

    León, Sergio Cruz; Prentiss, Mara; Fyta, Maria

    2016-06-01

    The binding energies of complexes of DNA nucleobase pairs are evaluated using quantum mechanical calculations at the level of dispersion corrected density functional theory. We begin with Watson-Crick base pairs of singlets, duplets, and triplets and calculate their binding energies. At a second step, mismatches are incorporated into the Watson-Crick complexes in order to evaluate the variation in the binding energy with respect to the canonical Watson-Crick pairs. A linear variation of this binding energy with the degree of mismatching is observed. The binding energies for the duplets and triplets containing mismatches are further compared to the energies of the respective singlets in order to assess the degree of collectivity in these complexes. This study also suggests that mismatches do not considerably affect the energetics of canonical base pairs. Our work is highly relevant to the recognition process in DNA promoted through the RecA protein and suggests a clear distinction between recognition in singlets, and recognition in duplets or triplets. Our work assesses the importance of collectivity in the homology recognition of DNA.

  15. Binding Energy of Molecules on Water Ice: Laboratory Measurements and Modeling

    CERN Document Server

    He, Jiao; Vidali, Gianfranco

    2016-01-01

    We measured the binding energy of N$_2$, CO, O$_2$, CH$_4$, and CO$_2$ on non-porous (compact) amorphous solid water (np-ASW), of N$_2$ and CO on porous amorphous solid water (p-ASW), and of NH$_3$ on crystalline water ice. We were able to measure binding energies down to a fraction of 1\\% of a layer, thus making these measurements more appropriate for astrochemistry than the existing values. We found that CO$_2$ forms clusters on np-ASW surface even at very low coverages. The binding energies of N$_2$, CO, O$_2$, and CH$_4$ decrease with coverage in the submonolayer regime. Their values at the low coverage limit are much higher than what is commonly used in gas-grain models. An empirical formula was used to describe the coverage dependence of the binding energies. We used the newly determined binding energy distributions in a simulation of gas-grain chemistry for cold cloud and hot core models. We found that owing to the higher value of desorption energy in the sub-monlayer regime a fraction of all these ice...

  16. Regional Differences in Muscle Energy Metabolism in Human Muscle by 31P-Chemical Shift Imaging.

    Science.gov (United States)

    Kime, Ryotaro; Kaneko, Yasuhisa; Hongo, Yoshinori; Ohno, Yusuke; Sakamoto, Ayumi; Katsumura, Toshihito

    2016-01-01

    Previous studies have reported significant region-dependent differences in the fiber-type composition of human skeletal muscle. It is therefore hypothesized that there is a difference between the deep and superficial parts of muscle energy metabolism during exercise. We hypothesized that the inorganic phosphate (Pi)/phosphocreatine (PCr) ratio of the superficial parts would be higher, compared with the deep parts, as the work rate increases, because the muscle fiber-type composition of the fast-type may be greater in the superficial parts compared with the deep parts. This study used two-dimensional 31Phosphorus Chemical Shift Imaging (31P-CSI) to detect differences between the deep and superficial parts of the human leg muscles during dynamic knee extension exercise. Six healthy men participated in this study (age 27±1 year, height 169.4±4.1 cm, weight 65.9±8.4 kg). The experiments were carried out with a 1.5-T superconducting magnet with a 5-in. diameter circular surface coil. The subjects performed dynamic one-legged knee extension exercise in the prone position, with the transmit-receive coil placed under the right quadriceps muscles in the magnet. The subjects pulled down an elastic rubber band attached to the ankle at a frequency of 0.25, 0.5 and 1 Hz for 320 s each. The intracellular pH (pHi) was calculated from the median chemical shift of the Pi peak relative to PCr. No significant difference in Pi/PCr was observed between the deep and the superficial parts of the quadriceps muscles at rest. The Pi/PCr of the superficial parts was not significantly increased with increasing work rate. Compared with the superficial areas, the Pi/PCr of the deep parts was significantly higher (p<0.05) at 1 Hz. The pHi showed no significant difference between the two parts. These results suggest that muscle oxidative metabolism is different between deep and superficial parts of quadriceps muscles during dynamic exercise. PMID:26782194

  17. Regional Differences in Muscle Energy Metabolism in Human Muscle by 31P-Chemical Shift Imaging.

    Science.gov (United States)

    Kime, Ryotaro; Kaneko, Yasuhisa; Hongo, Yoshinori; Ohno, Yusuke; Sakamoto, Ayumi; Katsumura, Toshihito

    2016-01-01

    Previous studies have reported significant region-dependent differences in the fiber-type composition of human skeletal muscle. It is therefore hypothesized that there is a difference between the deep and superficial parts of muscle energy metabolism during exercise. We hypothesized that the inorganic phosphate (Pi)/phosphocreatine (PCr) ratio of the superficial parts would be higher, compared with the deep parts, as the work rate increases, because the muscle fiber-type composition of the fast-type may be greater in the superficial parts compared with the deep parts. This study used two-dimensional 31Phosphorus Chemical Shift Imaging (31P-CSI) to detect differences between the deep and superficial parts of the human leg muscles during dynamic knee extension exercise. Six healthy men participated in this study (age 27±1 year, height 169.4±4.1 cm, weight 65.9±8.4 kg). The experiments were carried out with a 1.5-T superconducting magnet with a 5-in. diameter circular surface coil. The subjects performed dynamic one-legged knee extension exercise in the prone position, with the transmit-receive coil placed under the right quadriceps muscles in the magnet. The subjects pulled down an elastic rubber band attached to the ankle at a frequency of 0.25, 0.5 and 1 Hz for 320 s each. The intracellular pH (pHi) was calculated from the median chemical shift of the Pi peak relative to PCr. No significant difference in Pi/PCr was observed between the deep and the superficial parts of the quadriceps muscles at rest. The Pi/PCr of the superficial parts was not significantly increased with increasing work rate. Compared with the superficial areas, the Pi/PCr of the deep parts was significantly higher (p<0.05) at 1 Hz. The pHi showed no significant difference between the two parts. These results suggest that muscle oxidative metabolism is different between deep and superficial parts of quadriceps muscles during dynamic exercise.

  18. Theoretical prediction of the binding free energy for mutants of replication protein A.

    Science.gov (United States)

    Carra, Claudio; Saha, Janapriya; Cucinotta, Francis A

    2012-07-01

    The replication protein A (RPA) is a heterotrimeric (70, 32, and 14 kDa subunits), single stranded DNA (ssDNA) binding protein required for pivotal functions in the cell metabolism, such as chromosomal replication, prevention of hairpin formation, DNA repair and recombination, and signaling after DNA damage. Studies based on deletions and mutations have identified the high affinity ssDNA binding domains in the 70 kDa subunit of RPA, regions A and B. Individually, the domain A and B have a low affinity for ssDNA, while tandems composed of AA, AB, BB, and BA sequences bind the ssDNA with moderate to high affinity. Single and double point mutations on polar residues in the binding domains leads to a reduction in affinity of RPA for ssDNA, in particular when two hydrophilic residues are involved. In view of these results, we performed a study based on molecular dynamics simulation aimed to reproduce the experimental change in binding free energy, ΔΔG, of RPA70 mutants to further elucidate the nature of the protein-ssDNA interaction. The MM-PB(GB)SA methods implemented in Amber10 and the code FoldX were used to estimate the binding free energy. The theoretical and experimental ΔΔG values correlate better when the results are obtained by MM-PBSA calculated on individual trajectories for each mutant. In these conditions, the correlation coefficient between experimental and theoretical ΔΔG reaches a value of 0.95 despite the overestimation of the energy change by one order of magnitude. The decomposition of the MM-GBSA energy per residue allows us to correlate the change of the affinity with the residue polarity and energy contribution to the binding. The method revealed reliable predictions of the change in the affinity in function of mutations, and can be used to identify new mutants with distinct binding properties. PMID:22160652

  19. Energy Shift Caused by Non-isotropy of 2-Dimensional Anisotropic Quantum Dot in Presence of Uniform Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    FAN Hong-Yi; XU Xue-Fen

    2005-01-01

    Based on the squeezing mechanism in quantum dots in the presence of uniform magnetic field, we derive the energy shift caused by the non-isotropy of 2-dimensional anisotropic quantum dot. We also study sudden squeezing of the size of the quantum dot. The whole discussion is proceeded smoothly by virtue of the entangled state representation.

  20. Atomic Mass and NuclearBinding Energy for Uup-269(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-269 (Ununpentium, atomic number Z = 115, mass number A = 269).

  1. Atomic Mass and NuclearBinding Energy for Uup-335(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-335 (Ununpentium, atomic number Z = 115, mass number A = 335).

  2. Atomic Mass and NuclearBinding Energy for Uup-332(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-332 (Ununpentium, atomic number Z = 115, mass number A = 332).

  3. Atomic Mass and NuclearBinding Energy for Uup-326(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-326 (Ununpentium, atomic number Z = 115, mass number A = 326).

  4. Atomic Mass and NuclearBinding Energy for Uup-259(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-259 (Ununpentium, atomic number Z = 115, mass number A = 259).

  5. Atomic Mass and NuclearBinding Energy for Uup-300(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-300 (Ununpentium, atomic number Z = 115, mass number A = 300).

  6. Atomic Mass and NuclearBinding Energy for Uup-317(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-317 (Ununpentium, atomic number Z = 115, mass number A = 317).

  7. Atomic Mass and NuclearBinding Energy for Uup-304(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-304 (Ununpentium, atomic number Z = 115, mass number A = 304).

  8. Atomic Mass and NuclearBinding Energy for Uup-276(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-276 (Ununpentium, atomic number Z = 115, mass number A = 276).

  9. Atomic Mass and NuclearBinding Energy for Uup-271(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-271 (Ununpentium, atomic number Z = 115, mass number A = 271).

  10. Atomic Mass and NuclearBinding Energy for Uup-321(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-321 (Ununpentium, atomic number Z = 115, mass number A = 321).

  11. Atomic Mass and NuclearBinding Energy for Uup-294(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-294 (Ununpentium, atomic number Z = 115, mass number A = 294).

  12. Atomic Mass and NuclearBinding Energy for Uup-277(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-277 (Ununpentium, atomic number Z = 115, mass number A = 277).

  13. Atomic Mass and NuclearBinding Energy for Uup-310(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-310 (Ununpentium, atomic number Z = 115, mass number A = 310).

  14. Atomic Mass and NuclearBinding Energy for Uup-306(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-306 (Ununpentium, atomic number Z = 115, mass number A = 306).

  15. Atomic Mass and NuclearBinding Energy for Uup-323(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-323 (Ununpentium, atomic number Z = 115, mass number A = 323).

  16. Atomic Mass and NuclearBinding Energy for Uup-299(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-299 (Ununpentium, atomic number Z = 115, mass number A = 299).

  17. Atomic Mass and NuclearBinding Energy for Uup-286(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-286 (Ununpentium, atomic number Z = 115, mass number A = 286).

  18. Atomic Mass and NuclearBinding Energy for Uup-282(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-282 (Ununpentium, atomic number Z = 115, mass number A = 282).

  19. Atomic Mass and NuclearBinding Energy for Uup-338(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-338 (Ununpentium, atomic number Z = 115, mass number A = 338).

  20. Atomic Mass and NuclearBinding Energy for Uup-324(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-324 (Ununpentium, atomic number Z = 115, mass number A = 324).

  1. Atomic Mass and NuclearBinding Energy for Uup-322(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-322 (Ununpentium, atomic number Z = 115, mass number A = 322).

  2. Atomic Mass and NuclearBinding Energy for Uup-305(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-305 (Ununpentium, atomic number Z = 115, mass number A = 305).

  3. Atomic Mass and NuclearBinding Energy for Uup-336(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-336 (Ununpentium, atomic number Z = 115, mass number A = 336).

  4. Atomic Mass and NuclearBinding Energy for Uup-308(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-308 (Ununpentium, atomic number Z = 115, mass number A = 308).

  5. Atomic Mass and NuclearBinding Energy for Uup-291(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-291 (Ununpentium, atomic number Z = 115, mass number A = 291).

  6. Atomic Mass and NuclearBinding Energy for Uup-320(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-320 (Ununpentium, atomic number Z = 115, mass number A = 320).

  7. Atomic Mass and NuclearBinding Energy for Uup-261(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-261 (Ununpentium, atomic number Z = 115, mass number A = 261).

  8. Atomic Mass and NuclearBinding Energy for Uup-296(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-296 (Ununpentium, atomic number Z = 115, mass number A = 296).

  9. Atomic Mass and NuclearBinding Energy for Uup-272(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-272 (Ununpentium, atomic number Z = 115, mass number A = 272).

  10. Atomic Mass and NuclearBinding Energy for Uup-258(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-258 (Ununpentium, atomic number Z = 115, mass number A = 258).

  11. Atomic Mass and NuclearBinding Energy for Uup-273(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-273 (Ununpentium, atomic number Z = 115, mass number A = 273).

  12. Atomic Mass and NuclearBinding Energy for Uup-302(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-302 (Ununpentium, atomic number Z = 115, mass number A = 302).

  13. Atomic Mass and NuclearBinding Energy for Uup-289(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-289 (Ununpentium, atomic number Z = 115, mass number A = 289).

  14. Atomic Mass and NuclearBinding Energy for Uup-334(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-334 (Ununpentium, atomic number Z = 115, mass number A = 334).

  15. Atomic Mass and NuclearBinding Energy for Uup-316(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-316 (Ununpentium, atomic number Z = 115, mass number A = 316).

  16. Atomic Mass and NuclearBinding Energy for Uup-309(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-309 (Ununpentium, atomic number Z = 115, mass number A = 309).

  17. Atomic Mass and NuclearBinding Energy for Uup-262(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-262 (Ununpentium, atomic number Z = 115, mass number A = 262).

  18. Atomic Mass and NuclearBinding Energy for Uup-319(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-319 (Ununpentium, atomic number Z = 115, mass number A = 319).

  19. Atomic Mass and NuclearBinding Energy for Uup-314(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-314 (Ununpentium, atomic number Z = 115, mass number A = 314).

  20. Atomic Mass and NuclearBinding Energy for Uup-281(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-281 (Ununpentium, atomic number Z = 115, mass number A = 281).

  1. Atomic Mass and NuclearBinding Energy for Uup-267(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-267 (Ununpentium, atomic number Z = 115, mass number A = 267).

  2. Atomic Mass and NuclearBinding Energy for Uup-329(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-329 (Ununpentium, atomic number Z = 115, mass number A = 329).

  3. Atomic Mass and NuclearBinding Energy for Uup-264(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-264 (Ununpentium, atomic number Z = 115, mass number A = 264).

  4. Atomic Mass and NuclearBinding Energy for Uup-298(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-298 (Ununpentium, atomic number Z = 115, mass number A = 298).

  5. Atomic Mass and NuclearBinding Energy for Uup-339(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-339 (Ununpentium, atomic number Z = 115, mass number A = 339).

  6. Atomic Mass and NuclearBinding Energy for Uup-278(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-278 (Ununpentium, atomic number Z = 115, mass number A = 278).

  7. Atomic Mass and NuclearBinding Energy for Uup-312(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-312 (Ununpentium, atomic number Z = 115, mass number A = 312).

  8. Atomic Mass and NuclearBinding Energy for Uup-318(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-318 (Ununpentium, atomic number Z = 115, mass number A = 318).

  9. Atomic Mass and NuclearBinding Energy for Uup-270(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-270 (Ununpentium, atomic number Z = 115, mass number A = 270).

  10. Atomic Mass and NuclearBinding Energy for Uup-263(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-263 (Ununpentium, atomic number Z = 115, mass number A = 263).

  11. Atomic Mass and NuclearBinding Energy for Uup-313(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-313 (Ununpentium, atomic number Z = 115, mass number A = 313).

  12. Atomic Mass and NuclearBinding Energy for Uup-337(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-337 (Ununpentium, atomic number Z = 115, mass number A = 337).

  13. Atomic Mass and NuclearBinding Energy for Uup-287(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-287 (Ununpentium, atomic number Z = 115, mass number A = 287).

  14. Atomic Mass and NuclearBinding Energy for Uup-279(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-279 (Ununpentium, atomic number Z = 115, mass number A = 279).

  15. Atomic Mass and NuclearBinding Energy for Uup-275(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-275 (Ununpentium, atomic number Z = 115, mass number A = 275).

  16. Atomic Mass and NuclearBinding Energy for Uup-333(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-333 (Ununpentium, atomic number Z = 115, mass number A = 333).

  17. Atomic Mass and NuclearBinding Energy for Uup-280(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-280 (Ununpentium, atomic number Z = 115, mass number A = 280).

  18. Atomic Mass and NuclearBinding Energy for Uup-266(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-266 (Ununpentium, atomic number Z = 115, mass number A = 266).

  19. Atomic Mass and NuclearBinding Energy for Uup-330(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-330 (Ununpentium, atomic number Z = 115, mass number A = 330).

  20. Atomic Mass and NuclearBinding Energy for Uup-265(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-265 (Ununpentium, atomic number Z = 115, mass number A = 265).

  1. Atomic Mass and NuclearBinding Energy for Uup-283(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-283 (Ununpentium, atomic number Z = 115, mass number A = 283).

  2. Atomic Mass and NuclearBinding Energy for Uup-297(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-297 (Ununpentium, atomic number Z = 115, mass number A = 297).

  3. Atomic Mass and NuclearBinding Energy for Uup-268(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-268 (Ununpentium, atomic number Z = 115, mass number A = 268).

  4. Atomic Mass and NuclearBinding Energy for Uup-274(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-274 (Ununpentium, atomic number Z = 115, mass number A = 274).

  5. Atomic Mass and NuclearBinding Energy for Uup-260(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-260 (Ununpentium, atomic number Z = 115, mass number A = 260).

  6. Atomic Mass and NuclearBinding Energy for Uup-307(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-307 (Ununpentium, atomic number Z = 115, mass number A = 307).

  7. Atomic Mass and NuclearBinding Energy for Uup-293(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-293 (Ununpentium, atomic number Z = 115, mass number A = 293).

  8. Atomic Mass and NuclearBinding Energy for Uup-284(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-284 (Ununpentium, atomic number Z = 115, mass number A = 284).

  9. Atomic Mass and NuclearBinding Energy for Uup-292(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-292 (Ununpentium, atomic number Z = 115, mass number A = 292).

  10. Atomic Mass and NuclearBinding Energy for Uup-328(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-328 (Ununpentium, atomic number Z = 115, mass number A = 328).

  11. Atomic Mass and NuclearBinding Energy for Uup-331(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-331 (Ununpentium, atomic number Z = 115, mass number A = 331).

  12. Atomic Mass and NuclearBinding Energy for Uup-311(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-311 (Ununpentium, atomic number Z = 115, mass number A = 311).

  13. Atomic Mass and NuclearBinding Energy for Uup-285(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-285 (Ununpentium, atomic number Z = 115, mass number A = 285).

  14. Atomic Mass and NuclearBinding Energy for Uup-315(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-315 (Ununpentium, atomic number Z = 115, mass number A = 315).

  15. Atomic Mass and NuclearBinding Energy for Uup-288(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-288 (Ununpentium, atomic number Z = 115, mass number A = 288).

  16. Atomic Mass and NuclearBinding Energy for Uup-295(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-295 (Ununpentium, atomic number Z = 115, mass number A = 295).

  17. Atomic Mass and NuclearBinding Energy for Uup-301(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-301 (Ununpentium, atomic number Z = 115, mass number A = 301).

  18. Atomic Mass and NuclearBinding Energy for Uup-303(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-303 (Ununpentium, atomic number Z = 115, mass number A = 303).

  19. Atomic Mass and NuclearBinding Energy for Uup-290(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-290 (Ununpentium, atomic number Z = 115, mass number A = 290).

  20. Atomic Mass and NuclearBinding Energy for Uup-327(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-327 (Ununpentium, atomic number Z = 115, mass number A = 327).

  1. Atomic Mass and NuclearBinding Energy for Uup-325(Ununpentium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Uup-325 (Ununpentium, atomic number Z = 115, mass number A = 325).

  2. Nuclear binding energies: global collective structures and local shell-model correlations

    International Nuclear Information System (INIS)

    In this contribution the global behaviour of nuclear binding energies, or alternatively two-neutron separation energies, are studied. Recent high-precision mass measurements show local deviations from an overall macroscopic behaviour, and it is shown how a consistent and simultaneously description of both can be given within the Interacting Boson Model. (orig.)

  3. The relativistic one-loop and two-loop black-body radiation shift of atomic energy-levels

    OpenAIRE

    Zhou, Wanping; Mei, Xuesong; Qiao, Haoxue

    2016-01-01

    The thermal relativistic one-loop and two-loop self-energy corrections of atomic energy-levels induced by the blackbody radiation(BBR) are studied. We estimated the magnitude of BBR-shift of this results in the hydrogen-like atom. The order of magnitude indicated the two loop correction of the real photon is feeble, but that thermal relativistic one-loop self-energy correction and the thermal two-loop self-energy corrections induced by real and virtual photon are abnormal high, which may exce...

  4. The relativistic one-loop and two-loop black-body radiation shift of atomic energy-levels

    CERN Document Server

    Zhou, Wanping; Qiao, Haoxue

    2016-01-01

    The thermal relativistic one-loop and two-loop self-energy corrections of atomic energy-levels induced by the blackbody radiation(BBR) are studied. We estimated the magnitude of BBR-shift of this results in the hydrogen-like atom. The order of magnitude indicated the two loop correction of the real photon is feeble, but that thermal relativistic one-loop self-energy correction and the thermal two-loop self-energy corrections induced by real and virtual photon are abnormal high, which may exceed the leading order correction of BBR in the hydrogen with high $Z$ or low $T$.

  5. Theoretical studies on the binding energy of β-sheet models

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper,B3LYP and MP2 methods are used to investigate the binding energy of seventeen antiparallel and parallel β-sheet models. The results indicate that the binding energy obtained from B3LYP calculations is weaker than that obtained from MP2 calculations but the relative binding energy yielded by B3LYP is almost the same as that by MP2. For the antiparallel β-sheets in which two N―H···O═C hydrogen bonds can form either a large hydrogen-bonded ring or a small hydrogen-bonded ring,the binding energy increases obviously when one large ring unit is added,whereas it only changes slightly when one small ring unit is added because of the secondary electrostatic repulsive interaction existing in the small ring unit which is estimated to be about 20 kJ/mol. For the parallel β-sheet models,the binding energy increases almost exactly linearly with the increase of the chain length.

  6. Formation Mechanism and Binding Energy for Body-Centred Regular Icosahedral Structure of Li13 Cluster

    Institute of Scientific and Technical Information of China (English)

    LIU Wei-Na; LI Ping; GOU Qing-Quan; ZHAO Yan-Ping

    2008-01-01

    The formation mechanism for the body-centred regular icosahedral structure of Li13 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes for this structure of Li13 has been calculated by using the method of Gou's modified arrangement channel quantum mechanics (MACQM). The result shows that the curve has a minimal energy of-96.951 39 a.u. at R = 5.46a0. When R approaches to infinity, the total energy of thirteen lithium atoms has the value of-96.564 38 a.u. So the binding energy of Li13 with respect to thirteen lithium atoms is 0.387 01 a.u. Therefore the binding energy per atom for Li13 is 0.029 77 a.u. or 0.810 eV, which is greater than the binding energy per atom of 0.453 eV for Li2, 0.494 eV for Lia, 0.7878 eV for Li4, 0.632 eV for Lis, and 0.674 eV for Lit calculated by us previously. This means that the Li13 cluster may be formed stably in a body-centred regular icosahedral structure with a greater binding energy.

  7. Evaluating the energy and CO2 emissions impacts of shifts in residential water heating in the United States

    International Nuclear Information System (INIS)

    Water heating represented nearly 13% of 2010 residential energy consumption making it an important target for energy conservation efforts. The objective of this work is to identify spatially-resolved strategies for energy conservation, since little analysis has been done to identify how regional characteristics affect the energy consumed for water heating. We present a first-order thermodynamic analysis, utilizing ab initio calculations and regression methods, to quantify primary energy consumption and CO2 emissions with regional specificity by considering by considering local electricity mixes, heat rates, solar radiation profiles, heating degrees days, and water heating unit sales for 27 regions of the US. Results suggest that shifting from electric towards natural gas or solar water heating offered primary energy and CO2 emission reductions in most US regions, but these reductions varied considerably according to regional electricity mix and solar resources. We find that regions that would benefit most from technology transitions, are often least likely to switch due to limited economic incentives. Our results suggest that federal energy factor metrics, which ignore upstream losses in power generation, are insufficient in informing consumers about the energy performance of residential end use appliances. - Highlights: • US energy factor ratings for water heaters ignore upstream losses. • Switching from electric storage water heating reduces CO2 emissions in most US regions. • Regions with greatest potential for CO2 avoidance are least likely to shift technologies. • Benefits vary significantly according to climate and regional electricity fuel mix

  8. Odd-even staggering of binding energy for nuclei in the s d shell

    Science.gov (United States)

    Fu, G. J.; Cheng, Y. Y.; Jiang, H.; Zhao, Y. M.; Arima, A.

    2016-08-01

    In this paper we study odd-even staggering phenomena of binding energy in the framework of the nuclear shell model for nuclei in the s d shell. We decompose the USDB effective interaction into the monopole interaction and multipole (residual) interactions. We extract the empirical proton-neutron interaction, the Wigner energy, and the one-neutron separation energy using calculated binding energies. The monopole interaction, which represents the spherical mean field, provides contributions to the empirical proton-neutron interaction, the symmetry energy, and the Wigner energy. It does not induce odd-even staggering of the empirical proton-neutron interaction or the one-neutron separation energy. Isovector monopole and quadrupole pairing interactions and isoscalar spin-1 pairing interactions play a key role in reproducing an additional binding energy in both even-even and odd-odd nuclei. The Wigner energy coefficients are sensitive to residual two-body interactions. The nuclear shell structure has a strong influence on the evolution of the one-neutron separation energy, but not on empirical proton-neutron interactions. The so-called three-point formula is a good probe of the shell structure.

  9. Radii and Binding Energies in Oxygen Isotopes: A Challenge for Nuclear Forces.

    Science.gov (United States)

    Lapoux, V; Somà, V; Barbieri, C; Hergert, H; Holt, J D; Stroberg, S R

    2016-07-29

    We present a systematic study of both nuclear radii and binding energies in (even) oxygen isotopes from the valley of stability to the neutron drip line. Both charge and matter radii are compared to state-of-the-art ab initio calculations along with binding energy systematics. Experimental matter radii are obtained through a complete evaluation of the available elastic proton scattering data of oxygen isotopes. We show that, in spite of a good reproduction of binding energies, ab initio calculations with conventional nuclear interactions derived within chiral effective field theory fail to provide a realistic description of charge and matter radii. A novel version of two- and three-nucleon forces leads to considerable improvement of the simultaneous description of the three observables for stable isotopes but shows deficiencies for the most neutron-rich systems. Thus, crucial challenges related to the development of nuclear interactions remain.

  10. Radii and Binding Energies in Oxygen Isotopes: A Challenge for Nuclear Forces.

    Science.gov (United States)

    Lapoux, V; Somà, V; Barbieri, C; Hergert, H; Holt, J D; Stroberg, S R

    2016-07-29

    We present a systematic study of both nuclear radii and binding energies in (even) oxygen isotopes from the valley of stability to the neutron drip line. Both charge and matter radii are compared to state-of-the-art ab initio calculations along with binding energy systematics. Experimental matter radii are obtained through a complete evaluation of the available elastic proton scattering data of oxygen isotopes. We show that, in spite of a good reproduction of binding energies, ab initio calculations with conventional nuclear interactions derived within chiral effective field theory fail to provide a realistic description of charge and matter radii. A novel version of two- and three-nucleon forces leads to considerable improvement of the simultaneous description of the three observables for stable isotopes but shows deficiencies for the most neutron-rich systems. Thus, crucial challenges related to the development of nuclear interactions remain. PMID:27517768

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

    CERN Document Server

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

    2007-01-01

    An exponential dependence of the fragmentation cross-section on the average binding energy is observed and reproduced with a statistical model. The observed functional dependence is robust and allows the extraction of binding energies from measured cross-sections. From the systematics of 75,77,78,79Cu isotope cross-sections have been extracted. They are 636.94 +/- 0.40 MeV, 647.1 +/- 0.4 MeV, 651.6 +/- 0.4 MeV and 657.8 +/- 0.5 MeV, respectively. Specifically, the uncertainty of the binding energy of 75Cu is reduced from 980 keV (listed value in the 2003 mass table of Audi and Wapstra) to 400 keV. The predicted cross-sections of two near drip-line nuclei, 39Na and 40Mg, from the fragmentation of 48Ca are discussed.

  12. Radii and binding energies in oxygen isotopes: a puzzle for nuclear forces

    CERN Document Server

    Lapoux, V; Barbieri, C; Hergert, H; Holt, J D; Stroberg, R

    2016-01-01

    We present a systematic study of both nuclear radii and binding energies in (even) oxygen isotopes from the valley of stability to the neutron drip line. Both charge and matter radii are compared to state-of-the-art {\\it ab initio} calculations along with binding energy systematics. Experimental matter radii are obtained through a complete evaluation of the available elastic proton scattering data of oxygen isotopes. We show that, in spite of a good reproduction of binding energies, {\\it ab initio} calculations with conventional nuclear interactions derived within chiral effective field theory fail to provide a realistic description of charge and matter radii. A novel version of two- and three-nucleon forces leads to considerable improvement of the simultaneous description of the three observables for stable isotopes, but shows deficiencies for the most neutron-rich systems. Thus, crucial challenges related to the development of nuclear interactions remain.

  13. Docking study and binding free energy calculation of poly (ADP-ribose) polymerase inhibitors.

    Science.gov (United States)

    Ohno, Kazuki; Mitsui, Takashi; Tanida, Yoshiaki; Matsuura, Azuma; Fujitani, Hideaki; Niimi, Tatsuya; Orita, Masaya

    2011-02-01

    Recently, the massively parallel computation of absolute binding free energy with a well-equilibrated system (MP-CAFEE) has been developed. The present study aimed to determine whether the MP-CAFEE method is useful for drug discovery research. In the drug discovery process, it is important for computational chemists to predict the binding affinity accurately without detailed structural information for protein/ligand complex. We investigated the absolute binding free energies for Poly (ADP-ribose) polymerase-1 (PARP-1)/inhibitor complexes, using the MP-CAFEE method. Although each docking model was used as an input structure, it was found that the absolute binding free energies calculated by MP-CAFEE are well consistent with the experimental ones. The accuracy of this method is much higher than that using molecular mechanics Poisson-Boltzmann/surface area (MM/PBSA). Although the simulation time is quite extensive, the reliable predictor of binding free energies would be a useful tool for drug discovery projects. PMID:20480380

  14. SH3 domain-peptide binding energy calculations based on structural ensemble and multiple peptide templates.

    Directory of Open Access Journals (Sweden)

    Seungpyo Hong

    Full Text Available SH3 domains mediate signal transduction by recognizing short peptides. Understanding of the driving forces in peptide recognitions will help us to predict the binding specificity of the domain-peptide recognition and to understand the molecular interaction networks of cells. However, accurate calculation of the binding energy is a tough challenge. In this study, we propose three ideas for improving our ability to predict the binding energy between SH3 domains and peptides: (1 utilizing the structural ensembles sampled from a molecular dynamics simulation trajectory, (2 utilizing multiple peptide templates, and (3 optimizing the sequence-structure mapping. We tested these three ideas on ten previously studied SH3 domains for which SPOT analysis data were available. The results indicate that calculating binding energy using the structural ensemble was most effective, clearly increasing the prediction accuracy, while the second and third ideas tended to give better binding energy predictions. We applied our method to the five SH3 targets in DREAM4 Challenge and selected the best performing method.

  15. Improved ligand binding energies derived from molecular dynamics: replicate sampling enhances the search of conformational space.

    Science.gov (United States)

    Adler, Marc; Beroza, Paul

    2013-08-26

    Does a single molecular trajectory provide an adequate sample conformational space? Our calculations indicate that for Molecular Mechanics--Poisson-Boltzmann Surface Area (MM-PBSA) measurement of protein ligand binding, a single molecular dynamics trajectory does not provide a representative sampling of phase space. For a single trajectory, the binding energy obtained by averaging over a number of molecular dynamics frames in an equilibrated system will converge after an adequate simulation time. A separate trajectory with nearly identical starting coordinates (1% randomly perturbed by 0.001 Å), however, can lead to a significantly different calculated binding energy. Thus, even though the calculated energy converges for a single molecular dynamics run, the variation across separate runs implies that a single run inadequately samples the system. The divergence in the trajectories is reflected in the individual energy components, such as the van der Waals and the electrostatics terms. These results indicate that the trajectories sample different conformations that are not in rapid exchange. Extending the length of the dynamics simulation does not resolve the energy differences observed between different trajectories. By averaging over multiple simulations, each with a nearly equivalent starting structure, we find the standard deviation in the calculated binding energy to be ∼1.3 kcal/mol. The work presented here indicates that combining MM-PBSA with multiple samples of the initial starting coordinates will produce more precise and accurate estimates of protein/ligand affinity. PMID:23845109

  16. Distribution of binding energies of a water molecule in the water liquid-vapor interface

    Energy Technology Data Exchange (ETDEWEB)

    Chempath, Shaji [Los Alamos National Laboratory; Pratt, Lawrence R [TULANE UNIV

    2008-01-01

    Distributions of binding energies of a water molecule in the water liquid-vapor interface are obtained on the basis of molecular simulation with the SPC/E model of water. These binding energies together with the observed interfacial density profile are used to test a minimally conditioned Gaussian quasi-chemical statistical thermodynamic theory. Binding energy distributions for water molecules in that interfacial region clearly exhibit a composite structure. A minimally conditioned Gaussian quasi-chemical model that is accurate for the free energy of bulk liquid water breaks down for water molecules in the liquid-vapor interfacial region. This breakdown is associated with the fact that this minimally conditioned Gaussian model would be inaccurate for the statistical thermodynamics of a dilute gas. Aggressive conditioning greatly improves the performance of that Gaussian quasi-chemical model. The analogy between the Gaussian quasi-chemical model and dielectric models of hydration free energies suggests that naive dielectric models without the conditioning features of quasi-chemical theory will be unreliable for these interfacial problems. Multi-Gaussian models that address the composite nature of the binding energy distributions observed in the interfacial region might provide a mechanism for correcting dielectric models for practical applications.

  17. Exciton size and binding energy limitations in one-dimensional organic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kraner, S., E-mail: stefan.kraner@iapp.de; Koerner, C.; Leo, K. [Institut für Angewandte Photophysik, Technische Universität Dresden, Dresden (Germany); Scholz, R. [Institut für Angewandte Photophysik, Technische Universität Dresden, Dresden (Germany); Dresden Center of Computational Materials Science, Technische Universität Dresden, D-01062 Dresden (Germany); Plasser, F. [Institute for Theoretical Chemistry, University of Vienna, A-1090 Vienna (Austria)

    2015-12-28

    In current organic photovoltaic devices, the loss in energy caused by the charge transfer step necessary for exciton dissociation leads to a low open circuit voltage, being one of the main reasons for rather low power conversion efficiencies. A possible approach to avoid these losses is to tune the exciton binding energy to a value of the order of thermal energy, which would lead to free charges upon absorption of a photon, and therefore increase the power conversion efficiency towards the Shockley-Queisser limit. We determine the size of the excitons for different organic molecules and polymers by time dependent density functional theory calculations. For optically relevant transitions, the exciton size saturates around 0.7 nm for one-dimensional molecules with a size longer than about 4 nm. For the ladder-type polymer poly(benzimidazobenzophenanthroline), we obtain an exciton binding energy of about 0.3 eV, serving as a lower limit of the exciton binding energy for the organic materials investigated. Furthermore, we show that charge transfer transitions increase the exciton size and thus identify possible routes towards a further decrease of the exciton binding energy.

  18. Protein:Ligand binding free energies: A stringent test for computational protein design.

    Science.gov (United States)

    Druart, Karen; Palmai, Zoltan; Omarjee, Eyaz; Simonson, Thomas

    2016-02-01

    A computational protein design method is extended to allow Monte Carlo simulations where two ligands are titrated into a protein binding pocket, yielding binding free energy differences. These provide a stringent test of the physical model, including the energy surface and sidechain rotamer definition. As a test, we consider tyrosyl-tRNA synthetase (TyrRS), which has been extensively redesigned experimentally. We consider its specificity for its substrate l-tyrosine (l-Tyr), compared to the analogs d-Tyr, p-acetyl-, and p-azido-phenylalanine (ac-Phe, az-Phe). We simulate l- and d-Tyr binding to TyrRS and six mutants, and compare the structures and binding free energies to a more rigorous "MD/GBSA" procedure: molecular dynamics with explicit solvent for structures and a Generalized Born + Surface Area model for binding free energies. Next, we consider l-Tyr, ac- and az-Phe binding to six other TyrRS variants. The titration results are sensitive to the precise rotamer definition, which involves a short energy minimization for each sidechain pair to help relax bad contacts induced by the discrete rotamer set. However, when designed mutant structures are rescored with a standard GBSA energy model, results agree well with the more rigorous MD/GBSA. As a third test, we redesign three amino acid positions in the substrate coordination sphere, with either l-Tyr or d-Tyr as the ligand. For two, we obtain good agreement with experiment, recovering the wildtype residue when l-Tyr is the ligand and a d-Tyr specific mutant when d-Tyr is the ligand. For the third, we recover His with either ligand, instead of wildtype Gln.

  19. Effect of medium dependent binding energies on inferring the temperatures and freeze-out density of disassembling hot nuclear matter from cluster yields

    CERN Document Server

    Shlomo, S; Natowitz, J B; Qin, L; Hagel, K; Wada, R; Bonasera, A

    2009-01-01

    We explore the abundance of light clusters in asymmetric nuclear matter at subsaturation density. With increasing density, binding energies and wave functions are modified due to medium effects. The method of Albergo, Costa, Costanzo and Rubbino (ACCR) for determining the temperature and free nucleon density of a disassembling hot nuclear source from fragment yields is modified to include, in addition to Coulomb effects and flow, also effects of medium modifications of cluster properties, which become of importance when the nuclear matter density is above 10$^{-3}$ fm$^{-3}$. We show how the analysis of cluster yields, to infer temperature and nucleon densities, is modified if the shifts in binding energies of in medium clusters are included. While, at low densities, the temperature calculated from given yields changes only modestly if medium effects are taken into account, larger discrepancies are observed when the nucleon densities are determined from measured yields.

  20. Binding energy of a bound polaron in a quantum well wire

    International Nuclear Information System (INIS)

    Theoretical study of the binding energies of an off-center donor hydrogenic impurity in a cylindrical quantum well wires semiconductor is presented. Calculations are performed in the framework of the effective mass approximation using the variational approach. We describe the effect of the quantum confinement by an infinitely deep potential well and we take into consideration the interaction between the charge carrier (electron and ion) and the optical phonons (confined longitudinal optical and surface optical). Our results show that the impunity binding energy depends strongly on the spatial confinement, the impurity position and the polaronic corrections. (author)

  1. Increased efficiencies on CdTe solar cells via luminescence down-shifting with excitation energy transfer between dyes

    OpenAIRE

    Danos, Lefteris; Parel, Thomas; Markvart, Tom; Barrioz, Vincent; Brooks, William; Irvine, Stuart

    2012-01-01

    The external quantum efficiencies of CdTe solar cells fabricated by the atmospheric pressure metal organic chemical vapour deposition (AP–MOCVD) method have been measured with one and two dye doped luminescence down-shifting (LDS) layers on top. Excitation energy transfer between the dyes is used to extend the absorption ability of the LDS layer to λ=350 nm and increase the external quantum efficiency (EQE) of the cells for wavelengths λ

  2. Estimating binding free energy of a putative growth factors EGF-VEGF complex - a computational bioanalytical study.

    Science.gov (United States)

    Lin, Meng-Han; Chang, C Allen; Fischer, Wolfgang B

    2016-08-01

    Epidermal growth factor (EGF) and homodimeric vascular endothelial growth factor (VEGF) bind to cell surface receptors. They are responsible for cell growth and angiogenesis, respectively. Docking of the individual proteins as monomeric units using ZDOCK 2.3.2 reveals a partial blocking of the receptor binding site of VEGF by EGF. The receptor binding site of EGF is not affected by VEGF. The calculated binding energy is found to be intermediate between the binding energies calculated for Alzheimer's Aß42 and the barnase/barstar complex. PMID:26338536

  3. What if solar energy becomes really cheap? A thought experiment on environmental problem shifting

    NARCIS (Netherlands)

    Bergh, Van den Jeroen; Folke, Carl; Polasky, Stephen; Scheffer, Marten; Steffen, Will

    2015-01-01

    Solving one environmental problem may often invoke or intensify another one. Such environmental problem shifting (EPS) is a neglected topic in global sustainability research. Indeed, it is difficult to study as it requires the merging of insights from various research areas. Here we identify rele

  4. Alignment of RNA molecules: Binding energy and statistical properties of random sequences

    Energy Technology Data Exchange (ETDEWEB)

    Valba, O. V., E-mail: valbaolga@gmail.com [Moscow Institute of Physics and Technology (State University) (Russian Federation); Nechaev, S. K., E-mail: sergei.nechaev@gmail.com [Universite Paris Sud, LPTMS (France); Tamm, M. V., E-mail: thumm.m@gmail.com [Moscow State University (Russian Federation)

    2012-02-15

    A new statistical approach to the problem of pairwise alignment of RNA sequences is proposed. The problem is analyzed for a pair of interacting polymers forming an RNA-like hierarchical cloverleaf structures. An alignment is characterized by the numbers of matches, mismatches, and gaps. A weight function is assigned to each alignment; this function is interpreted as a free energy taking into account both direct monomer-monomer interactions and a combinatorial contribution due to formation of various cloverleaf secondary structures. The binding free energy is determined for a pair of RNA molecules. Statistical properties are discussed, including fluctuations of the binding energy between a pair of RNA molecules and loop length distribution in a complex. Based on an analysis of the free energy per nucleotide pair complexes of random RNAs as a function of the number of nucleotide types c, a hypothesis is put forward about the exclusivity of the alphabet c = 4 used by nature.

  5. On the many-body Van der Waals binding energy of a dense fluid

    NARCIS (Netherlands)

    Nijboer, B.R.A.

    1975-01-01

    We consider a dense system of neutral atoms. When the atoms are represented by isotropic oscillators (Drude-Lorentz model) interacting with nonretarded dipole-dipole forces, the binding energy of the system is given exactly by a well-known expression which is written as a sum of two-bond, three-bond

  6. PBSA_E: A PBSA-Based Free Energy Estimator for Protein-Ligand Binding Affinity.

    Science.gov (United States)

    Liu, Xiao; Liu, Jinfeng; Zhu, Tong; Zhang, Lujia; He, Xiao; Zhang, John Z H

    2016-05-23

    Improving the accuracy of scoring functions for estimating protein-ligand binding affinity is of significant interest as well as practical utility in drug discovery. In this work, PBSA_E, a new free energy estimator based on the molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) descriptors, has been developed. This free energy estimator was optimized using high-quality experimental data from a training set consisting of 145 protein-ligand complexes. The method was validated on two separate test sets containing 121 and 130 complexes. Comparison of the binding affinities predicted using the present method with those obtained using three popular scoring functions, i.e., GlideXP, GlideSP, and SYBYL_F, demonstrated that the PBSA_E method is more accurate. This new energy estimator requires a MM/PBSA calculation of the protein-ligand binding energy for a single complex configuration, which is typically obtained by optimizing the crystal structure. The present study shows that PBSA_E has the potential to become a robust tool for more reliable estimation of protein-ligand binding affinity in structure-based drug design. PMID:27088302

  7. Increased binding energy of impurities near a semiconductor-vacuum interface

    Energy Technology Data Exchange (ETDEWEB)

    Wijnheijmer, A.P.; Garleff, J.K.; Koenraad, P.M. [PSN, Eindhoven University of Technology (Netherlands); Teichmann, K.; Wenderoth, M.; Loth, S.; Ulbrich, R.G. [IV. Phys. Inst., Georg-August Univ. Goettingen (Germany)

    2008-07-01

    We have recently shown that a STM tip can be used as a tool to manipulate the charge state of individual impurities below the cleavage surface of a semiconductor. This manipulation allowed us to determine the binding energy of single donors and acceptors as a function of their depth (up to 1 nm) below the surface. We found that the binding energy strongly increases near the surface. In the case of a Si-donor in GaAs the binding energy increases continuously from 5.6 meV in the bulk to about 150 meV close to the surface. Our STM techniques also allowed for the determination of the size and shape of the Coulomb field of single ionized donors. We found that the range of the potential is strongly reduced relative to the bulk value. Both the reduced range of the Coulomb potential and the increased binding energy can be related to a reduced dielectric constant and increased effective mass near the surface. We discuss the implications of these findings.

  8. Comparison of experimental and theoretical binding and transition energies in the actinide region. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Krause, M.O.; Nestor, C.W. Jr.

    1977-01-01

    The status of experimental and theoretical binding and transition energy determinations is reviewed extending the comparison between experiment and theory to encompass representative series of data for all actinides. This comprehensive comparison reveals areas where improvements may be indicated, showing whether theoretical treatments including all known contributions to the lowest order would be adequate in all instances. 45 references. (JFP)

  9. Determination of the Exciton Binding Energy Using Photothermal and Photoluminescence Spectroscopy

    Science.gov (United States)

    Strzałkowski, K.; Zakrzewski, J.; Maliński, M.

    2013-04-01

    In this paper, experimental photoluminescence (PL) and piezoelectric photothermal (PPT) spectra of selected II-VI binary crystals are presented and analyzed. The quantitative analysis of the photothermal spectra was performed using a modified and extended Jackson-Amer model. The values of the bandgap energies of investigated semiconductors were computed from the PT amplitude and phase spectra. From the temperature dependence of the exciton emission so-called "excitonic energy gaps" have been determined. It follows from the theory that the exciton binding energy is the difference of these two values of energy gaps derived from PPT and PL spectroscopy.

  10. Molecular dynamics simulations and binding free energy analysis of DNA minor groove complexes of curcumin.

    Science.gov (United States)

    Koonammackal, Mathew Varghese; Nellipparambil, Unnikrishnan Viswambharan Nair; Sudarsanakumar, Chellappanpillai

    2011-11-01

    Curcumin is a natural phytochemical that exhibits a wide range of pharmacological properties, including antitumor and anticancer activities. The similarity in the shape of curcumin to DNA minor groove binding drugs is the motivation for exploring its binding affinity in the minor grooves of DNA sequences. Interactions of curcumin with DNA have not been extensively examined, while its pharmacological activities have been studied and documented in depth. Curcumin was docked with two DNA duplexes, d(GTATATAC)(2) and d(CGCGATATCGCG)(2), and molecular dynamics simulations of the complexes were performed in explicit solvent to determine the stability of the binding. In all systems, the curcumin is positioned in the minor groove in the A·T region, and was stably bound throughout the simulation, causing only minor modifications to the structural parameters of DNA. Water molecules were found to contribute to the stability of the binding of the ligand. Free energy analyses of the complexes were performed with MM-PBSA, and the binding affinities that were calculated are comparable to the values reported for other similar nucleic acid-ligand systems, indicating that curcumin is a suitable natural molecule for the development of minor groove binding drugs. PMID:21287216

  11. Improving the LIE Method for Binding Free Energy Calculations of Protein-Ligand Complexes.

    Science.gov (United States)

    Miranda, Williams E; Noskov, Sergei Yu; Valiente, Pedro A

    2015-09-28

    In this work, we introduced an improved linear interaction energy (LIE) method parameterization for computations of protein–ligand binding free energies. The protocol, coined LIE-D, builds on the linear relationship between the empirical coefficient γ in the standard LIE scheme and the D parameter, introduced in our work. The D-parameter encompasses the balance (difference) between electrostatic (polar) and van der Waals (nonpolar) energies in protein–ligand complexes. Leave-one-out cross-validation showed that LIE-D reproduced accurately the absolute binding free energies for our training set of protein–ligand complexes ( = 0.92 kcal/mol, SDerror = 0.66 kcal/mol, R(2) = 0.90, QLOO(2) = 0.89, and sPRESS(LOO) = 1.28 kcal/mol). We also demonstrated LIE-D robustness by predicting accurately the binding free energies for three different protein–ligand systems outside the training data set, where the electrostatic and van der Waals interaction energies were calculated with different force fields.

  12. Black-body radiation shift of atomic energy-levels:The $ (Z \\alpha)^2\\alpha T^2/m $ correction

    CERN Document Server

    Zhou, Wanping; Lu, Jingjun; Qiao, Haoxue

    2016-01-01

    The next-to-leading order black-body radiation(BBR) shift to atomic energy-levels, namely $ (Z\\alpha)^2\\alpha T^2/m $ correction, was studied by using the nonrelativistic quantum electrodynamics(NRQED) at first. This $T^{2}$-dependent correction has not been investigated before, and only contains the contribution of eletric-dipole of thermal photon. In order to study the contribution of multipolar. We estimate the two-loop contributions of BBR-shift by using quantum electrodynamics approach(QED), and find both one-loop and two-loop diagram contribute to the $ (Z\\alpha)^2\\alpha T^2/m $ correction. Integrating the results which are obtained by these two approaches, the $ (Z\\alpha)^2\\alpha T^2/m $ correction we derived is in principle applicable to multi-electron atoms and contains the contribution of multipolar. The order of magnitude BBR-shift indicates this next-to-leading order BBR-shift may be as significant as the leading order in the multi-electron atoms or cold ones.

  13. Large-scale molecular dynamics simulation: Effect of polarization on thrombin-ligand binding energy.

    Science.gov (United States)

    Duan, Li L; Feng, Guo Q; Zhang, Qing G

    2016-01-01

    Molecular dynamics (MD) simulations lasting 500 ns were performed in explicit water to investigate the effect of polarization on the binding of ligands to human α-thrombin based on the standard nonpolarizable AMBER force field and the quantum-derived polarized protein-specific charge (PPC). The PPC includes the electronic polarization effect of the thrombin-ligand complex, which is absent in the standard force field. A detailed analysis and comparison of the results of the MD simulation with experimental data provided strong evidence that intra-protein, protein-ligand hydrogen bonds and the root-mean-square deviation of backbone atoms were significantly stabilized through electronic polarization. Specifically, two critical hydrogen bonds between thrombin and the ligand were broken at approximately 190 ns when AMBER force field was used and the number of intra-protein backbone hydrogen bonds was higher under PPC than under AMBER. The thrombin-ligand binding energy was computed using the molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) method, and the results were consistent with the experimental value obtained using PPC. Because hydrogen bonds were unstable, it was failed to predict the binding affinity under the AMBER force field. Furthermore, the results of the present study revealed that differences in the binding free energy between AMBER and PPC almost comes from the electrostatic interaction. Thus, this study provides evidence that protein polarization is critical to accurately describe protein-ligand binding. PMID:27507430

  14. Large-scale molecular dynamics simulation: Effect of polarization on thrombin-ligand binding energy

    Science.gov (United States)

    Duan, Li L.; Feng, Guo Q.; Zhang, Qing G.

    2016-01-01

    Molecular dynamics (MD) simulations lasting 500 ns were performed in explicit water to investigate the effect of polarization on the binding of ligands to human α-thrombin based on the standard nonpolarizable AMBER force field and the quantum-derived polarized protein-specific charge (PPC). The PPC includes the electronic polarization effect of the thrombin-ligand complex, which is absent in the standard force field. A detailed analysis and comparison of the results of the MD simulation with experimental data provided strong evidence that intra-protein, protein-ligand hydrogen bonds and the root-mean-square deviation of backbone atoms were significantly stabilized through electronic polarization. Specifically, two critical hydrogen bonds between thrombin and the ligand were broken at approximately 190 ns when AMBER force field was used and the number of intra-protein backbone hydrogen bonds was higher under PPC than under AMBER. The thrombin-ligand binding energy was computed using the molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) method, and the results were consistent with the experimental value obtained using PPC. Because hydrogen bonds were unstable, it was failed to predict the binding affinity under the AMBER force field. Furthermore, the results of the present study revealed that differences in the binding free energy between AMBER and PPC almost comes from the electrostatic interaction. Thus, this study provides evidence that protein polarization is critical to accurately describe protein-ligand binding. PMID:27507430

  15. Development of computational methods for the prediction of protein structure, protein binding, and mutational effects using free energy calculations.

    OpenAIRE

    Becker, Caroline

    2014-01-01

    A molecular understanding of protein-protein or protein-ligand binding is of crucial importance for the design of proteins or ligands with defined binding characteristics. The comprehensive analysis of biomolecular binding and the coupled rational in silico design of protein-ligand interfaces requires both, accurate and computationally fast methods for the prediction of free energies. Accurate free energy methods usually involve atomistic molecular dynamics simulations that are computationall...

  16. Constrained consumption shifting management in the distributed energy resources scheduling considering demand response

    International Nuclear Information System (INIS)

    Highlights: • Consumption reduction and/or shift to several periods before and after. • Optimization problem for scheduling of demand response and distributed generation. • Minimization of the Virtual Power Player operation (remuneration) costs. • Demand response can be efficient to meet distributed generation shortages. • Consumers benefit with the remuneration of the participation in demand response. - Abstract: Demand response concept has been gaining increasing importance while the success of several recent implementations makes this resource benefits unquestionable. This happens in a power systems operation environment that also considers an intensive use of distributed generation. However, more adequate approaches and models are needed in order to address the small size consumers and producers aggregation, while taking into account these resources goals. The present paper focuses on the demand response programs and distributed generation resources management by a Virtual Power Player that optimally aims to minimize its operation costs taking the consumption shifting constraints into account. The impact of the consumption shifting in the distributed generation resources schedule is also considered. The methodology is applied to three scenarios based on 218 consumers and 4 types of distributed generation, in a time frame of 96 periods

  17. Free energy calculations to estimate ligand-binding affinities in structure-based drug design.

    Science.gov (United States)

    Reddy, M Rami; Reddy, C Ravikumar; Rathore, R S; Erion, Mark D; Aparoy, P; Reddy, R Nageswara; Reddanna, P

    2014-01-01

    Post-genomic era has led to the discovery of several new targets posing challenges for structure-based drug design efforts to identify lead compounds. Multiple computational methodologies exist to predict the high ranking hit/lead compounds. Among them, free energy methods provide the most accurate estimate of predicted binding affinity. Pathway-based Free Energy Perturbation (FEP), Thermodynamic Integration (TI) and Slow Growth (SG) as well as less rigorous end-point methods such as Linear interaction energy (LIE), Molecular Mechanics-Poisson Boltzmann./Generalized Born Surface Area (MM-PBSA/GBSA) and λ-dynamics have been applied to a variety of biologically relevant problems. The recent advances in free energy methods and their applications including the prediction of protein-ligand binding affinity for some of the important drug targets have been elaborated. Results using a recently developed Quantum Mechanics (QM)/Molecular Mechanics (MM) based Free Energy Perturbation (FEP) method, which has the potential to provide a very accurate estimation of binding affinities to date has been discussed. A case study for the optimization of inhibitors for the fructose 1,6- bisphosphatase inhibitors has been described. PMID:23947646

  18. Nuclear binding energies: Global collective structure and local shell-model correlations

    International Nuclear Information System (INIS)

    Nuclear binding energies and two-neutron separation energies are analysed starting from the liquid-drop model and the nuclear shell model in order to describe the global trends of the above observables. We subsequently concentrate on the Interacting Boson Model (IBM) and discuss a new method in order to provide a consistent description of both, ground-state and excited-state properties. We address the artefacts that appear when crossing mid-shell using the IBM formulation and perform detailed numerical calculations for nuclei situated in the 50-82 shell. We also concentrate on local deviations from the above global trends in binding energy and two-neutron separation energies that appear in the neutron-deficient Pb region. We address possible effects on the binding energy, caused by mixing of low-lying 0+ intruder states into the ground state, using configuration mixing in the IBM framework. We also study ground-state properties using a macroscopic-microscopic model. Detailed comparisons with recent experimental data in the Pb region are amply discussed

  19. Energy harvesting and transient computing: a paradigm shift for embedded systems?

    OpenAIRE

    Merrett, Geoff V

    2016-01-01

    Embedded systems powered from time-varying energy harvesting sources traditionally operate using the principles of energy-neutral computing: over a certain period of time, the energy that they consume equals the energy that they harvest. This has the significant advantage of making the system ‘look like’ a battery-powered system, yet typically results in large, complex and expensive power conversion circuitry and introduces numerous challenges including fast and reliable cold-start. In recent...

  20. Imaging G protein-coupled receptors while quantifying their ligand-binding free-energy landscape.

    Science.gov (United States)

    Alsteens, David; Pfreundschuh, Moritz; Zhang, Cheng; Spoerri, Patrizia M; Coughlin, Shaun R; Kobilka, Brian K; Müller, Daniel J

    2015-09-01

    Imaging native membrane receptors and testing how they interact with ligands is of fundamental interest in the life sciences but has proven remarkably difficult to accomplish. Here, we introduce an approach that uses force-distance curve-based atomic force microscopy to simultaneously image single native G protein-coupled receptors in membranes and quantify their dynamic binding strength to native and synthetic ligands. We measured kinetic and thermodynamic parameters for individual protease-activated receptor-1 (PAR1) molecules in the absence and presence of antagonists, and these measurements enabled us to describe PAR1's ligand-binding free-energy landscape with high accuracy. Our nanoscopic method opens an avenue to directly image and characterize ligand binding of native membrane receptors. PMID:26167642

  1. What role for microgeneration in a shift to a low carbon domestic energy sector in the UK?

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, N.; Eyre, N. [Environmental Change Institute, School of Geography and Environment, University of Oxford, South Parks Road, Oxford, OX1 3QY (United Kingdom)

    2011-06-15

    Domestic energy use accounts for more than a quarter of CO2 emissions in the UK. Traditional approaches to energy reduction look at direct emissions savings, and recommend insulation and efficiency as more cost-effective than microgeneration. However, microgeneration has indirect, 'soft' benefits and could play a significant role in emissions reduction. Current uptake of microgeneration in the UK is low, with various barriers-economic, technical, cultural, behavioural and institutional-both to uptake and to maximising energy and emissions savings once installed. Subsidies and spreading information alone do not guarantee maximising uptake, and even if successful, this is not enough to maximise savings. The industry focuses on maximising sales, with no incentives to ensure best installations and use; householders do not have access to the best information, and user behaviour does not maximise energy and emission savings. This is related to a broader state of socio-technical 'lock-in' in domestic energy use; there's a lack of connection between personal behaviour and energy consumption, let alone global climate change. This suggests that a major cultural-behavioural shift is needed to reduce energy/emissions in the home. Transition theory and strategic niche management provide insights into possible systemic change and a suitable framework for future policies, such as supporting a variety of radically innovative niches, both technological and social. Microgeneration, properly employed, has the potential to play a part in such a transition by increasing awareness and energy literacy and empowering people to seriously engage in energy debates as producers, as well as consumers, of energy. This deeper understanding and heightened responsibility are crucial in a shift toward bottom-up emission-reducing behaviour change and better acceptance of top-down energy-saving policy measures, as part of a new domestic energy paradigm. The implications for

  2. Analytical formulas for carrier density and Fermi energy in semiconductors with a tight-binding band

    International Nuclear Information System (INIS)

    Analytical formulas for evaluating the relation of carrier density and Fermi energy for semiconductors with a tight-binding band have been proposed. The series expansions for a carrier density with fast convergency have been obtained by means of a Bessel function. A simple and analytical formula for Fermi energy has been derived with the help of the Gauss integration method. The results of the proposed formulas are in good agreement with accurate numerical solutions. The formulas have been successfully used in the calculation of carrier density and Fermi energy in a miniband superlattice system. Their accuracy is in the order of 10−5. (paper)

  3. Mode shift strategies in intercity transportation and their effect on energy consumption

    Science.gov (United States)

    Sokolsky, S.

    1975-01-01

    Policies are examined which, if implemented, could lead to significant energy savings in intercity travel in the northeast corridor arena, without restricting the traveler's freedom of mode choice. The effects on arena energy consumption of introducing new, more energy-efficient aircraft are investigated; and several strategies unrelated to the implementation of new aircraft are introduced to yield reductions in overall intercity energy use. In both parts of this analysis, resulting changes in patronage (modal share) and energy use are demonstrated, leading to new insights into the effectiveness of different potential policies for achieving energy conservation. Some observations on induced demand trends that could be associated with certain strategies and the resultant potential effect on energy conservation are provided.

  4. Assessment of Density Functional Methods for Exciton Binding Energies and Related Optoelectronic Properties

    CERN Document Server

    Lee, Jui-Che; Lin, Shiang-Tai

    2015-01-01

    The exciton binding energy, the energy required to dissociate an excited electron-hole pair into free charge carriers, is one of the key factors to the optoelectronic performance of organic materials. However, it remains unclear whether modern quantum-mechanical calculations, mostly based on Kohn-Sham density functional theory (KS-DFT) and time-dependent density functional theory (TDDFT), are reliably accurate for exciton binding energies. In this study, the exciton binding energies and related optoelectronic properties (e.g., the ionization potentials, electron affinities, fundamental gaps, and optical gaps) of 121 small- to medium-sized molecules are calculated using KS-DFT and TDDFT with various density functionals. Our KS-DFT and TDDFT results are compared with those calculated using highly accurate CCSD and EOM-CCSD methods, respectively. The omegaB97, omegaB97X, and omegaB97X-D functionals are shown to generally outperform (with a mean absolute error of 0.36 eV) other functionals for the properties inve...

  5. Dielectric confinement on exciton binding energy and nonlinear optical properties in a strained Zn1-xinMgxinSe/Zn1-xoutMgxoutSe quantum well

    Institute of Scientific and Technical Information of China (English)

    J. Abraham Hudson Mark; A. John Peter

    2012-01-01

    The band offsets for a Zn1-xinMgxin Se/Zn1-xoutMgxout Se quantum well heterostructure are determined using the model solid theory.The heavy hole exciton binding energies are investigated with various Mg alloy contents.The effect of mismatch between the dielectric constants between the well and the barrier is taken into account.The dependence of the excitonic transition energies on the geometrical confinement and the Mg alloy is discussed.Non-linear optical properties are determined using the compact density matrix approach.The linear,third order non-linear optical absorption coefficient values and the refractive index changes of the exciton are calculated for different concentrations of magnesium.The results show that the occurred blue shifts of the resonant peak due to the Mg incorporation give the information about the variation of two energy levels in the quantum well width.

  6. Calculation of positron binding energies using the generalized any particle propagator theory

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Jonathan; Charry, Jorge A. [Department of Chemistry, Universidad Nacional de Colombia, Av. Cra. 30 #45-03, Bogotá (Colombia); Flores-Moreno, Roberto [Departamento de Química, Universidad de Guadalajara, Blvd. Marcelino García Barragán 1421, Guadalajara Jal., C. P. 44430 (Mexico); Varella, Márcio T. do N. [Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970 São Paulo, SP (Brazil); Reyes, Andrés, E-mail: areyesv@unal.edu.co [Department of Chemistry, Universidad Nacional de Colombia, Av. Cra. 30 #45-03, Bogotá (Colombia); Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970 São Paulo, SP (Brazil)

    2014-09-21

    We recently extended the electron propagator theory to any type of quantum species based in the framework of the Any-Particle Molecular Orbital (APMO) approach [J. Romero, E. Posada, R. Flores-Moreno, and A. Reyes, J. Chem. Phys. 137, 074105 (2012)]. The generalized any particle molecular orbital propagator theory (APMO/PT) was implemented in its quasiparticle second order version in the LOWDIN code and was applied to calculate nuclear quantum effects in electron binding energies and proton binding energies in molecular systems [M. Díaz-Tinoco, J. Romero, J. V. Ortiz, A. Reyes, and R. Flores-Moreno, J. Chem. Phys. 138, 194108 (2013)]. In this work, we present the derivation of third order quasiparticle APMO/PT methods and we apply them to calculate positron binding energies (PBEs) of atoms and molecules. We calculated the PBEs of anions and some diatomic molecules using the second order, third order, and renormalized third order quasiparticle APMO/PT approaches and compared our results with those previously calculated employing configuration interaction (CI), explicitly correlated and quantum Montecarlo methodologies. We found that renormalized APMO/PT methods can achieve accuracies of ∼0.35 eV for anionic systems, compared to Full-CI results, and provide a quantitative description of positron binding to anionic and highly polar species. Third order APMO/PT approaches display considerable potential to study positron binding to large molecules because of the fifth power scaling with respect to the number of basis sets. In this regard, we present additional PBE calculations of some small polar organic molecules, amino acids and DNA nucleobases. We complement our numerical assessment with formal and numerical analyses of the treatment of electron-positron correlation within the quasiparticle propagator approach.

  7. Trends in adsorbate induced core level shifts

    Science.gov (United States)

    Nilsson, Viktor; Van den Bossche, Maxime; Hellman, Anders; Grönbeck, Henrik

    2015-10-01

    Photoelectron core level spectroscopy is commonly used to monitor atomic and molecular adsorption on metal surfaces. As changes in the electron binding energies are convoluted measures with different origins, calculations are often used to facilitate the decoding of experimental signatures. The interpretation could in this sense benefit from knowledge on trends in surface core level shifts for different metals and adsorbates. Here, density functional theory calculations have been used to systematically evaluate core level shifts for (111) and (100) surfaces of 3d, 4d, and 5d transition metals upon CO, H, O and S adsorption. The results reveal trends and several non-intuitive cases. Moreover, the difficulties correlating core level shifts with charging and d-band shifts are underlined.

  8. Excitonic fine structure and binding energies of excitonic complexes in single InAs quantum dashes

    Science.gov (United States)

    Mrowiński, P.; Zieliński, M.; Świderski, M.; Misiewicz, J.; Somers, A.; Reithmaier, J. P.; Höfling, S.; Sek, G.

    2016-09-01

    The fundamental electronic and optical properties of elongated InAs nanostructures embedded in quaternary InGaAlAs barrier are investigated by means of high-resolution optical spectroscopy and many-body atomistic tight-binding theory. These wire-like shaped, self-assembled nanostructures are known as quantum dashes and are typically formed during the molecular beam epitaxial growth on InP substrates. In this paper, we study properties of excitonic complexes confined in quantum dashes emitting in a broad spectral range from below 1.2 to 1.55 μm. We find peculiar trends for the biexciton and negative trion binding energies, with pronounced trion binding in smaller size quantum dashes. These experimental findings are then compared and qualitatively explained by atomistic theory. The theoretical analysis shows a fundamental role of correlation effects for the absolute values of excitonic binding energies. Eventually, we determine the bright exciton fine structure splitting (FSS), where both the experiment and theory predict a broad distribution of the splitting varying from below 50 to almost 180 μeV. We identify several key factors determining the FSS values in such nanostructures, including quantum dash size variation and composition fluctuations.

  9. Converging ligand-binding free energies obtained with free-energy perturbations at the quantum mechanical level.

    Science.gov (United States)

    Olsson, Martin A; Söderhjelm, Pär; Ryde, Ulf

    2016-06-30

    In this article, the convergence of quantum mechanical (QM) free-energy simulations based on molecular dynamics simulations at the molecular mechanics (MM) level has been investigated. We have estimated relative free energies for the binding of nine cyclic carboxylate ligands to the octa-acid deep-cavity host, including the host, the ligand, and all water molecules within 4.5 Å of the ligand in the QM calculations (158-224 atoms). We use single-step exponential averaging (ssEA) and the non-Boltzmann Bennett acceptance ratio (NBB) methods to estimate QM/MM free energy with the semi-empirical PM6-DH2X method, both based on interaction energies. We show that ssEA with cumulant expansion gives a better convergence and uses half as many QM calculations as NBB, although the two methods give consistent results. With 720,000 QM calculations per transformation, QM/MM free-energy estimates with a precision of 1 kJ/mol can be obtained for all eight relative energies with ssEA, showing that this approach can be used to calculate converged QM/MM binding free energies for realistic systems and large QM partitions. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:27117350

  10. Communication: Physical origins of ionization potential shifts in mixed carboxylic acids and water complexes

    Science.gov (United States)

    Gu, Quanli; Tang, Zhen; Su, Peifeng; Wu, Wei; Yang, Zhijun; Trindle, Carl O.; Knee, Joseph L.

    2016-08-01

    The ionization potential (IP) of the aromatic alpha hydroxy carboxylic acid, 9-hydroxy-9-fluorene carboxylic acid (9HFCA), is shifted by complexation with hydrogen bonding ligands such as water and formic acid. Generalized Kohn-Sham energy decomposition analysis decomposes the intermolecular binding energies into a frozen energy term, polarization, correlation, and/or dispersion energy terms, as well as terms of geometric relaxation and zero point energy. We observe that in each dimer the attractive polarization always increases upon ionization, enhancing binding in the cation and shifting the IP toward the red. For 9HFCA—H2O, a substantial decrease of the repulsive frozen energy in cation further shifts the IP toward red. For 9HFCA—HCOOH, the increase of the frozen energy actually occurs in the cation and shifts the IP toward blue. Consistent with the experimental measurements, our analysis provides new, non-intuitive perspectives on multiple hydrogen bonds interactions in carboxylic acids and water complexes.

  11. Chemical shift changes provide evidence for overlapping single-stranded DNA and XPA binding sites on the 70 kDa subunit of human replication protein A

    Energy Technology Data Exchange (ETDEWEB)

    Daughdrill, Gary W.; Buchko, Garry W.; Botuyan, Maria V.; Arrowsmith, Cheryl H.; Wold, Marc S.; Kennedy, Michael A.; Lowry, David F.

    2003-07-15

    Replication protein A (RPA) is a heterotrimeric single-stranded DNA (ssDNA) binding protein that can form a complex with the xeroderma pigmentosum group A protein (XPA). This complex can preferentially recognize UV damaged DNA over undamaged DNA and has been implicated in the stabilization of open complex formation during nucleotide excision repair. In this report, NMR spectroscopy was used to investigate the interaction between a fragment of the 70 kDa subunit of human RPA, residues 1-326 (hRPA701-326), and a fragment of the human XPA protein, residues 98-219 (XPA-MBD). Intensity changes were observed for amide resonances in the 1H-15N correlation spectrum of uniformly 15N-labeled hRPA701-326 after the addition of unlabeled XPA-MBD. The intensity changes observed were restricted to an ssDNA binding domain that is between residues 183 and 296 of the hRPA701-326 fragment. The hRPA701-326 residues with the largest resonance intensity reductions were mapped onto the structure of the ssDNA binding domain to identify the binding surface with XPA-MBD. The XPA-MBD binding surface showed significant overlap with an ssDNA binding surface that was previously identified using NMR spectroscopy and X-ray crystallography.

  12. Load Shifting Control and Management of Domestic Microgeneration Systems for Improved Energy Efficiency and Comfort

    DEFF Research Database (Denmark)

    Anvari-Moghaddam, Amjad; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.

    2015-01-01

    In this paper, an intelligent energy management system based on energy saving and user’s comfort is introduced and applied to a residential smart home as a case study. The proposed multi-objective mixed-integer nonlinear programming (MINLP)-based architecture takes the advantages of several key...

  13. Binding Energies of D- Centers Trapped by a Quantum Dot in a Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2009-01-01

    A investigation of the properties of the bound states of D- centers confined in a parabolic quantum dot has been performed for the case with the presence of a perpendicular magnetic field.Calculations are carried out by using the method of numerical diagonalization of Hamiltonian matrix within the effective-mass approximation.The binding energies of the ground and some bound-excited states are obtained as a function of the applied magnetic field strength.Detailed calculations of the binding energies for a number of low-lying states show that for field strength less than B = 2.1 T, the D- center confined in a quantum dot possesses two bound states, for 2.1 ≤ B < 2.4 T, there exist three bound states, etc.Further relevant characteristics of the D- center quantum dots in magnetic fields are provided.

  14. Improved Computation of Protein-Protein Relative Binding Energies with the Nwat-MMGBSA Method.

    Science.gov (United States)

    Maffucci, Irene; Contini, Alessandro

    2016-09-26

    A MMGBSA variant (here referred to as Nwat-MMGBSA), based on the inclusion of a certain number of explicit water molecules (Nwat) during the calculations, has been tested on a set of 20 protein-protein complexes, using the correlation between predicted and experimental binding energy as the evaluation metric. Besides the Nwat parameter, the effect of the force field, the molecular dynamics simulation length, and the implicit solvent model used in the MMGBSA analysis have been also evaluated. We found that considering 30 interfacial water molecules improved the correlation between predicted and experimental binding energies by up to 30%, compared to the standard approach. Moreover, the correlation resulted in being rather sensitive to the force field and, to a minor extent, to the implicit solvent model and to the length of the MD simulation. PMID:27500550

  15. On the release of binding energy and accretion power in core collapse-like environments

    CERN Document Server

    Socrates, Aristotle

    2008-01-01

    All accretion models of gamma-ray bursts share a common assumption: accretion power and gravitational binding energy is released and then dissipated locally, with the mass of its origin. This is equivalent to the Shakura-Sunyaev 1973 (SS73) prescription for the dissipation of accretion power and subsequent conversion into radiate output. Since their seminal paper, broadband observations of quasars and black hole X-ray binaries insist that the SS73 prescription cannot wholly describe their behavior. In particular, optically thick black hole accretion flows are almost universally accompanied by coronae whose relative power by far exceeds anything seen in studies of stellar chromospheric and coronal activity. In this note, we briefly discuss the possible repercussions of freeing accretion models of GRBs from the SS73 prescription. Our main conclusion is that the efficiency of converting gravitational binding energy into a GRB power can be increased by an order of magnitude or more.

  16. Simulative Calculation of Mechanical Property, Binding Energy and Detonation Property of TATB/Fluorine-polymer PBX

    Institute of Scientific and Technical Information of China (English)

    MA, Xiu-Fang; XIAO, Ji-Jun; HUANG, Hui; JU, Xue-Hai; LI, Jin-Shan; XIAO, He-Ming

    2006-01-01

    Molecular dynamics (MD) method was used to simulate 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) coated with fluorine containing polymers. The mechanical properties and binding energies of PBXs were obtained. It was found that when the number of chain monomers of fluorine containing polymers was the same, the elasticity of TATB/F2314 was increased more greatly than others and the binding energy of TATB/F2311 was the largest among four PBXs. Detonation heat and velocity of such four PBXs were calculated according to theoretical and empirical formulas. The results show that the order of detonation heat is TATB>TATB/PVDF>TATB/F2311 >TATB/F2314>TATB/PCTFE while the order of detonation velocity is TATB/PVDF<TATB/F2311 <TATB/F2314<TATB/PCTFE<TATB.

  17. Relationships between ligand binding sites, protein architecture and correlated paths of energy and conformational fluctuations

    International Nuclear Information System (INIS)

    The statistical thermodynamics basis of energy and residue position fluctuations is explained for native proteins. The protein and its surroundings are treated as a canonical system with emphasis on the effects of energy exchange between the two. Fluctuations of the energy are related to fluctuations of residue positions, which in turn are related to the connectivity matrix of the protein, thus establishing a connection between energy fluctuation pathways and protein architecture. The model gives the locations of hotspots for ligand binding and identifies the pathways of energy conduction within the protein. Results are discussed in terms of two sets of models, the BPTI and 12 proteins that contain the PDZ domain. A possible use of the model for determining functionally similar domains in a diverse set of proteins is pointed out

  18. Two- and three-body interatomic dispersion energy contributions to binding in molecules and solids

    Science.gov (United States)

    Anatole von Lilienfeld, O.; Tkatchenko, Alexandre

    2010-06-01

    We present numerical estimates of the leading two- and three-body dispersion energy terms in van der Waals interactions for a broad variety of molecules and solids. The calculations are based on London and Axilrod-Teller-Muto expressions where the required interatomic dispersion energy coefficients, C6 and C9, are computed "on the fly" from the electron density. Inter- and intramolecular energy contributions are obtained using the Tang-Toennies (TT) damping function for short interatomic distances. The TT range parameters are equally extracted on the fly from the electron density using their linear relationship to van der Waals radii. This relationship is empiricially determined for all the combinations of He-Xe rare gas dimers, as well as for the He and Ar trimers. The investigated systems include the S22 database of noncovalent interactions, Ar, benzene and ice crystals, bilayer graphene, C60 dimer, a peptide (Ala10), an intercalated drug-DNA model [ellipticine-d(CG)2], 42 DNA base pairs, a protein (DHFR, 2616 atoms), double stranded DNA (1905 atoms), and 12 molecular crystal polymorphs from crystal structure prediction blind test studies. The two- and three-body interatomic dispersion energies are found to contribute significantly to binding and cohesive energies, for bilayer graphene the latter reaches 50% of experimentally derived binding energy. These results suggest that interatomic three-body dispersion potentials should be accounted for in atomistic simulations when modeling bulky molecules or condensed phase systems.

  19. Binding Energy of an Exciton in the Quantum Dot Under a Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-nng

    2001-01-01

    The author reports on a calculation of the binding energy of the ground and some excited states of excitons in parabolic quantum dots in the presence of an external magnetic field. Calculations are made by using the method of few-body physics within the effective-mass approximation. The results are obtained for several strength values of the magnetic field as a function of the quantum dot radius.

  20. Binding energies of an exciton in a Gaussian potential quantum dot

    Institute of Scientific and Technical Information of China (English)

    Xie Wen-Fang

    2006-01-01

    In this paper, an exciton trapped by a Gaussian confining potential quantum dot has been investigated. Calculations are made by using the method of numerical diagonalization of Hamiltonian in the effective-mass approximation. The dependences of binding energies of the ground state and the first excited state on the size of the confining potential and the strength of the magnetic field are analysed explicitly.

  1. Adding energy minimization strategy to peptide-design algorithm enables better search for RNA-binding peptides: Redesigned λ N peptide binds boxB RNA.

    Science.gov (United States)

    Xiao, Xingqing; Hung, Michelle E; Leonard, Joshua N; Hall, Carol K

    2016-10-15

    Our previously developed peptide-design algorithm was improved by adding an energy minimization strategy which allows the amino acid sidechains to move in a broad configuration space during sequence evolution. In this work, the new algorithm was used to generate a library of 21-mer peptides which could substitute for λ N peptide in binding to boxB RNA. Six potential peptides were obtained from the algorithm, all of which exhibited good binding capability with boxB RNA. Atomistic molecular dynamics simulations were then conducted to examine the ability of the λ N peptide and three best evolved peptides, viz. Pept01, Pept26, and Pept28, to bind to boxB RNA. Simulation results demonstrated that our evolved peptides are better at binding to boxB RNA than the λ N peptide. Sequence searches using the old (without energy minimization strategy) and new (with energy minimization strategy) algorithms confirm that the new algorithm is more effective at finding good RNA-binding peptides than the old algorithm. © 2016 Wiley Periodicals, Inc.

  2. Binding mode and free energy prediction of fisetin/β-cyclodextrin inclusion complexes

    Science.gov (United States)

    Nutho, Bodee; Khuntawee, Wasinee; Rungnim, Chompoonut; Pongsawasdi, Piamsook; Wolschann, Peter; Karpfen, Alfred; Kungwan, Nawee

    2014-01-01

    Summary In the present study, our aim is to investigate the preferential binding mode and encapsulation of the flavonoid fisetin in the nano-pore of β-cyclodextrin (β-CD) at the molecular level using various theoretical approaches: molecular docking, molecular dynamics (MD) simulations and binding free energy calculations. The molecular docking suggested four possible fisetin orientations in the cavity through its chromone or phenyl ring with two different geometries of fisetin due to the rotatable bond between the two rings. From the multiple MD results, the phenyl ring of fisetin favours its inclusion into the β-CD cavity, whilst less binding or even unbinding preference was observed in the complexes where the larger chromone ring is located in the cavity. All MM- and QM-PBSA/GBSA free energy predictions supported the more stable fisetin/β-CD complex of the bound phenyl ring. Van der Waals interaction is the key force in forming the complexes. In addition, the quantum mechanics calculations with M06-2X/6-31G(d,p) clearly showed that both solvation effect and BSSE correction cannot be neglected for the energy determination of the chosen system. PMID:25550745

  3. Binding mode and free energy prediction of fisetin/β-cyclodextrin inclusion complexes

    Directory of Open Access Journals (Sweden)

    Bodee Nutho

    2014-11-01

    Full Text Available In the present study, our aim is to investigate the preferential binding mode and encapsulation of the flavonoid fisetin in the nano-pore of β-cyclodextrin (β-CD at the molecular level using various theoretical approaches: molecular docking, molecular dynamics (MD simulations and binding free energy calculations. The molecular docking suggested four possible fisetin orientations in the cavity through its chromone or phenyl ring with two different geometries of fisetin due to the rotatable bond between the two rings. From the multiple MD results, the phenyl ring of fisetin favours its inclusion into the β-CD cavity, whilst less binding or even unbinding preference was observed in the complexes where the larger chromone ring is located in the cavity. All MM- and QM-PBSA/GBSA free energy predictions supported the more stable fisetin/β-CD complex of the bound phenyl ring. Van der Waals interaction is the key force in forming the complexes. In addition, the quantum mechanics calculations with M06-2X/6-31G(d,p clearly showed that both solvation effect and BSSE correction cannot be neglected for the energy determination of the chosen system.

  4. Binding energies of exciton complexes in transition metal dichalcogenide monolayers and effect of dielectric environment

    Science.gov (United States)

    Kylänpää, Ilkka; Komsa, Hannu-Pekka

    2015-11-01

    Excitons, trions, biexcitons, and exciton-trion complexes in two-dimensional transition metal dichalcogenide sheets of MoS2, MoSe2, MoTe2, WS2, and WSe2 are studied by means of density functional theory and path-integral Monte Carlo method in order to accurately account for the particle-particle correlations. In addition, the effect of dielectric environment on the properties of these exciton complexes is studied by modifying the effective interaction potential between particles. Calculated exciton and trion binding energies are consistent with previous experimental and computational studies, and larger systems such as biexciton and exciton-trion complex are found highly stable. Binding energies of biexcitons are similar to or higher than those of trions, but the binding energy of the trion depends significantly stronger on the dielectric environment than that of biexciton. Therefore, as a function of an increasing dielectric constant of the environment the exciton-trion complex "dissociates" to a biexciton rather than to an exciton and a trion.

  5. Electrostatics, structure prediction, and the energy landscapes for protein folding and binding.

    Science.gov (United States)

    Tsai, Min-Yeh; Zheng, Weihua; Balamurugan, D; Schafer, Nicholas P; Kim, Bobby L; Cheung, Margaret S; Wolynes, Peter G

    2016-01-01

    While being long in range and therefore weakly specific, electrostatic interactions are able to modulate the stability and folding landscapes of some proteins. The relevance of electrostatic forces for steering the docking of proteins to each other is widely acknowledged, however, the role of electrostatics in establishing specifically funneled landscapes and their relevance for protein structure prediction are still not clear. By introducing Debye-Hückel potentials that mimic long-range electrostatic forces into the Associative memory, Water mediated, Structure, and Energy Model (AWSEM), a transferable protein model capable of predicting tertiary structures, we assess the effects of electrostatics on the landscapes of thirteen monomeric proteins and four dimers. For the monomers, we find that adding electrostatic interactions does not improve structure prediction. Simulations of ribosomal protein S6 show, however, that folding stability depends monotonically on electrostatic strength. The trend in predicted melting temperatures of the S6 variants agrees with experimental observations. Electrostatic effects can play a range of roles in binding. The binding of the protein complex KIX-pKID is largely assisted by electrostatic interactions, which provide direct charge-charge stabilization of the native state and contribute to the funneling of the binding landscape. In contrast, for several other proteins, including the DNA-binding protein FIS, electrostatics causes frustration in the DNA-binding region, which favors its binding with DNA but not with its protein partner. This study highlights the importance of long-range electrostatics in functional responses to problems where proteins interact with their charged partners, such as DNA, RNA, as well as membranes.

  6. Assessment of Solvated Interaction Energy Function for Ranking Antibody-Antigen Binding Affinities.

    Science.gov (United States)

    Sulea, Traian; Vivcharuk, Victor; Corbeil, Christopher R; Deprez, Christophe; Purisima, Enrico O

    2016-07-25

    Affinity modulation of antibodies and antibody fragments of therapeutic value is often required in order to improve their clinical efficacies. Virtual affinity maturation has the potential to quickly focus on the critical hotspot residues without the combinatorial explosion problem of conventional display and library approaches. However, this requires a binding affinity scoring function that is capable of ranking single-point mutations of a starting antibody. We focus here on assessing the solvated interaction energy (SIE) function that was originally developed for and is widely applied to scoring of protein-ligand binding affinities. To this end, we assembled a structure-function data set called Single-Point Mutant Antibody Binding (SiPMAB) comprising several antibody-antigen systems suitable for this assessment, i.e., based on high-resolution crystal structures for the parent antibodies and coupled with high-quality binding affinity measurements for sets of single-point antibody mutants in each system. Using this data set, we tested the SIE function with several mutation protocols based on the popular methods SCWRL, Rosetta, and FoldX. We found that the SIE function coupled with a protocol limited to sampling only the mutated side chain can reasonably predict relative binding affinities with a Spearman rank-order correlation coefficient of about 0.6, outperforming more aggressive sampling protocols. Importantly, this performance is maintained for each of the seven system-specific component subsets as well as for other relevant subsets including non-alanine and charge-altering mutations. The transferability and enrichment in affinity-improving mutants can be further enhanced using consensus ranking over multiple methods, including the SIE, Talaris, and FOLDEF energy functions. The knowledge gained from this study can lead to successful prospective applications of virtual affinity maturation. PMID:27367467

  7. A nonorthogonal tight-binding total energy model for molecular simulations

    International Nuclear Information System (INIS)

    A nonorthogonal tight-binding (TB) total energy model for molecular simulations has been developed in spirit of extended-Hueckel theory. The semiempirical potential parameters for H, C, O elements are fitted from density functional theory (DFT) calculations. The test calculations on small inorganic molecules, hydrocarbons, fullerenes, and large organic molecules show its reliability and transferability. In particular, the atomization energies and the gaps between highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO-LUMO gaps) from TB model compare well with DFT results for a variety of molecules. Thus, our TB model can be used in the large scale simulation of molecules and carbon-based materials

  8. Efficient Computation of Small-Molecule Configurational Binding Entropy and Free Energy Changes by Ensemble Enumeration.

    Science.gov (United States)

    Silver, Nathaniel W; King, Bracken M; Nalam, Madhavi N L; Cao, Hong; Ali, Akbar; Kiran Kumar Reddy, G S; Rana, Tariq M; Schiffer, Celia A; Tidor, Bruce

    2013-11-12

    Here we present a novel, end-point method using the dead-end-elimination and A* algorithms to efficiently and accurately calculate the change in free energy, enthalpy, and configurational entropy of binding for ligand-receptor association reactions. We apply the new approach to the binding of a series of human immunodeficiency virus (HIV-1) protease inhibitors to examine the effect ensemble reranking has on relative accuracy as well as to evaluate the role of the absolute and relative ligand configurational entropy losses upon binding in affinity differences for structurally related inhibitors. Our results suggest that most thermodynamic parameters can be estimated using only a small fraction of the full configurational space, and we see significant improvement in relative accuracy when using an ensemble versus single-conformer approach to ligand ranking. We also find that using approximate metrics based on the single-conformation enthalpy differences between the global minimum energy configuration in the bound as well as unbound states also correlates well with experiment. Using a novel, additive entropy expansion based on conditional mutual information, we also analyze the source of ligand configurational entropy loss upon binding in terms of both uncoupled per degree of freedom losses as well as changes in coupling between inhibitor degrees of freedom. We estimate entropic free energy losses of approximately +24 kcal/mol, 12 kcal/mol of which stems from loss of translational and rotational entropy. Coupling effects contribute only a small fraction to the overall entropy change (1-2 kcal/mol) but suggest differences in how inhibitor dihedral angles couple to each other in the bound versus unbound states. The importance of accounting for flexibility in drug optimization and design is also discussed.

  9. Electrostatic component of binding energy: Interpreting predictions from poisson-boltzmann equation and modeling protocols.

    Science.gov (United States)

    Chakavorty, Arghya; Li, Lin; Alexov, Emil

    2016-10-30

    Macromolecular interactions are essential for understanding numerous biological processes and are typically characterized by the binding free energy. Important component of the binding free energy is the electrostatics, which is frequently modeled via the solutions of the Poisson-Boltzmann Equations (PBE). However, numerous works have shown that the electrostatic component (ΔΔGelec ) of binding free energy is very sensitive to the parameters used and modeling protocol. This prompted some researchers to question the robustness of PBE in predicting ΔΔGelec . We argue that the sensitivity of the absolute ΔΔGelec calculated with PBE using different input parameters and definitions does not indicate PBE deficiency, rather this is what should be expected. We show how the apparent sensitivity should be interpreted in terms of the underlying changes in several numerous and physical parameters. We demonstrate that PBE approach is robust within each considered force field (CHARMM-27, AMBER-94, and OPLS-AA) once the corresponding structures are energy minimized. This observation holds despite of using two different molecular surface definitions, pointing again that PBE delivers consistent results within particular force field. The fact that PBE delivered ΔΔGelec values may differ if calculated with different modeling protocols is not a deficiency of PBE, but natural results of the differences of the force field parameters and potential functions for energy minimization. In addition, while the absolute ΔΔGelec values calculated with different force field differ, their ordering remains practically the same allowing for consistent ranking despite of the force field used. © 2016 Wiley Periodicals, Inc.

  10. Shift reagents in ion mobility spectrometry: the effect of the number of interaction sites, size and interaction energies on the mobilities of valinol and ethanolamine.

    Science.gov (United States)

    Fernández-Maestre, Roberto; Meza-Morelos, Dairo; Wu, Ching

    2016-05-01

    Overlapping peaks interfere in ion mobility spectrometry (IMS), but they are separated introducing mobility shift reagents (SR) in the buffer gas forming adducts with different collision cross-sections (size). IMS separations using SR depend on the ion mobility shifts which are governed by adduct's size and interaction energies (stabilities). Mobility shifts of valinol and ethanolamine ions were measured by electrospray-ionization ion mobility-mass spectrometry (MS). Methyl-chloro propionate (M) was used as SR; 2-butanol (B) and nitrobenzene (N) were used for comparison. Density functional theory was used for calculations. B produced the smallest mobility shifts because of its small size. M and N have two strong interaction sites (oxygen atoms) and similar molecular mass, and they should produce similar shifts. For both ethanolamine and valinol ions, stabilities were larger for N adducts than those of M. With ethanolamine, M produced a 68% shift, large compared to that using N, 61%, because M has a third weak interaction site on the chlorine atom and, therefore, M has more interaction possibilities than N. This third site overrode the oxygen atoms' interaction energy that favored the adduction of ethanolamine with N over that with M. On the contrary, with valinol mobility shifts were larger with N than with M (21 vs 18%) because interaction energy favored even more adduction of valinol with N than with M; that is, the interaction energy difference between adducts of valinol with M and N was larger than that between those adducts with ethanolamine, and the third M interaction could not override this larger difference. Mobility shifts were explained based on the number of SR's interaction sites, size of ions and SR, and SR-ion interaction energies. This is the first time that the number of interaction sites is used to explain mobility shifts in SR-assisted IMS. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27194523

  11. Shift reagents in ion mobility spectrometry: the effect of the number of interaction sites, size and interaction energies on the mobilities of valinol and ethanolamine.

    Science.gov (United States)

    Fernández-Maestre, Roberto; Meza-Morelos, Dairo; Wu, Ching

    2016-05-01

    Overlapping peaks interfere in ion mobility spectrometry (IMS), but they are separated introducing mobility shift reagents (SR) in the buffer gas forming adducts with different collision cross-sections (size). IMS separations using SR depend on the ion mobility shifts which are governed by adduct's size and interaction energies (stabilities). Mobility shifts of valinol and ethanolamine ions were measured by electrospray-ionization ion mobility-mass spectrometry (MS). Methyl-chloro propionate (M) was used as SR; 2-butanol (B) and nitrobenzene (N) were used for comparison. Density functional theory was used for calculations. B produced the smallest mobility shifts because of its small size. M and N have two strong interaction sites (oxygen atoms) and similar molecular mass, and they should produce similar shifts. For both ethanolamine and valinol ions, stabilities were larger for N adducts than those of M. With ethanolamine, M produced a 68% shift, large compared to that using N, 61%, because M has a third weak interaction site on the chlorine atom and, therefore, M has more interaction possibilities than N. This third site overrode the oxygen atoms' interaction energy that favored the adduction of ethanolamine with N over that with M. On the contrary, with valinol mobility shifts were larger with N than with M (21 vs 18%) because interaction energy favored even more adduction of valinol with N than with M; that is, the interaction energy difference between adducts of valinol with M and N was larger than that between those adducts with ethanolamine, and the third M interaction could not override this larger difference. Mobility shifts were explained based on the number of SR's interaction sites, size of ions and SR, and SR-ion interaction energies. This is the first time that the number of interaction sites is used to explain mobility shifts in SR-assisted IMS. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Binding Energy of an Exciton Bound to Ionized Acceptor in Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2001-01-01

    Binding energiesfor an exciton (X ) trapped in the two-dimensional quantum dot by a negative ion located on the z axis at a distance from the dot plane are calculated by using the method of few-body physics.This configuration is called a barrier (A-,X) center.The dependence of the binding energy of the ground state of the barrier (A-,X)center on the electron-to-hole mass ratio for a few values of the distance d between the fixed negative ion on the z axis and the dot plane is obtained.We find that when d → 0,the barrier (A-,X) center has not any bound state.We also studied the stability and binding energy of the ground state of the barrier (A-,X) center in a parabolic quantum dot as a function of the distance d between the fixed negative ion on the z axis and the dot plane.``

  13. Photoelectron spectroscopy of aqueous solutions: Streaming potentials of NaX (X = Cl, Br, and I) solutions and electron binding energies of liquid water and X−

    International Nuclear Information System (INIS)

    The streaming potentials of liquid beams of aqueous NaCl, NaBr, and NaI solutions are measured using soft X-ray, He(I), and laser multiphoton ionization photoelectron spectroscopy. Gaseous molecules are ionized in the vicinity of liquid beams and the photoelectron energy shifts are measured as a function of the distance between the ionization point and the liquid beam. The streaming potentials change their polarity with concentration of electrolytes, from which the singular points of concentration eliminating the streaming potentials are determined. The streaming currents measured in air also vanish at these concentrations. The electron binding energies of liquid water and I−, Br−, and Cl− anions are revisited and determined more accurately than in previous studies

  14. Two and three-body interatomic dispersion energy contributions to binding in molecules and solids

    Science.gov (United States)

    von Lilienfeld, Anatole; Tkatchenko, Alexandre

    2010-03-01

    Numerical estimates of the leading two and three body dispersion energy terms in van der Waals (vdW) interactions are presented for a broad variety of molecules and solids. The calculations employ London and Axilrod-Teller-Muto expressions damped at short interatomic distances, where the required interatomic dispersion energy coefficients, C6 and C9, are computed from first-principles. The investigated systems include the S22 database of non-covalent interactions, benzene and ice crystals, bilayer graphene, fullerene dimer, a poly peptide (Ala10), an intercalated drug-DNA model (Ellipticine-d(CG)2), 42 DNA base pairs, a protein (DHFR, 2616 atoms), double stranded DNA (1905 atoms), and molecular crystals from a crystal structure blind test. We find that the 2 and 3-body interatomic dispersion energies contribute significantly to binding and cohesive energies, for some systems they can reach up to 50% of experimental estimates of absolute binding. Our results suggest that interatomic 3-body dispersion potentials should be accounted for in atomistic simulations when modeling bulky molecules or condensed phase systems.

  15. Cellulose chain binding free energy drives the processive move of cellulases on the cellulose surface.

    Science.gov (United States)

    Wang, Yefei; Zhang, Shujun; Song, Xiangfei; Yao, Lishan

    2016-09-01

    Processivity is essential for cellulases in their catalysis of cellulose hydrolysis. But what drives the processive move is not well understood. In this work, we use Trichoderma reesei Cel7B as a model system and show that its processivity is directly correlated to the binding free energy difference of a cellulose chain occupying the binding sites -7 to +2 and that occupying sites -7 to -1. Several mutants that have stronger interactions with glycosyl units in sites +1 and +2 than the wild type enzyme show higher processivity. The results suggest that after the release of the product cellobiose located in sites +1 and +2, the enzyme pulls the cellulose chain to fill the vacant sites, which propels its processive move on the cellulose surface. Biotechnol. Bioeng. 2016;113: 1873-1880. © 2016 Wiley Periodicals, Inc. PMID:26928155

  16. Energy shift of collective electron excitations in highly corrugated graphitic nanostructures: Experimental and theoretical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Sedelnikova, O. V., E-mail: o.sedelnikova@gmail.com; Bulusheva, L. G.; Okotrub, A. V. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Science, 3 Acad. Lavrentiev Ave., Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2 Pirogov Str., Novosibirsk 630090 (Russian Federation); Tomsk State University, 36 Lenina Ave., Tomsk 634050 (Russian Federation); Asanov, I. P. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Science, 3 Acad. Lavrentiev Ave., Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2 Pirogov Str., Novosibirsk 630090 (Russian Federation); Yushina, I. V. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Science, 3 Acad. Lavrentiev Ave., Novosibirsk 630090 (Russian Federation)

    2014-04-21

    Effect of corrugation of hexagonal carbon network on the collective electron excitations has been studied using optical absorption and X-ray photoelectron spectroscopy in conjunction with density functional theory calculations. Onion-like carbon (OLC) was taken as a material, where graphitic mantle enveloping agglomerates of multi-shell fullerenes is strongly curved. Experiments showed that positions of π and π + σ plasmon modes as well as π → π* absorption peak are substantially redshifted for OLC as compared with those of highly ordered pyrolytic graphite and thermally exfoliated graphite consisted of planar sheets. This effect was reproduced in behavior of dielectric functions of rippled graphite models calculated within the random phase approximation. We conclude that the energy of electron excitations in graphitic materials could be precisely tuned by a simple bending of hexagonal network without change of topology. Moreover, our investigation suggests that in such materials optical exciton can transfer energy to plasmon non-radiatively.

  17. Binding Energies of Excitons in Square Quantum-Well Wires in the Presence of a Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    张迎涛; 邸冰; 谢尊; 李有成

    2004-01-01

    The binding energies of the ground state of excitons in the GaAs/Ga1-xAlxAs square quantum-well wire in the presence of a magnetic field are investigated by using the variational method. It is assumed that the magnetic field is applied parallel to the axis of the wire. The calculations of the binding energy as a function of the wire size have been performed for infinite and finite confinement potentials. The contribution of the magnetic field makes the binding energy larger obviously, particularly for the wide wire, and the magnetic field is much more pronounced for the binding energy in a square quantum wire than that in a cylindrical quantum wire. The mismatch of effective masses between the well and the barrier is also considered in the calculation.

  18. Binding Energies and Scattering Observables in the 4^He_3 Atomic System

    OpenAIRE

    Motovilov, A. K.; Sandhas, W.; Sofianos, S. A.; Kolganova, E. A.

    1999-01-01

    The ^4He_3 bound states and the scattering of a ^4He atom off a ^4He dimer at ultra-low energies are investigated using a hard-core version of the Faddeev differential equations. Various realistic ^4He-^4He interactions were employed, amomg them the LM2M2 potential by Aziz and Slaman and the recent TTY potential by Tang, Toennies and Yiu. The ground state and the excited (Efimov) state obtained are compared with other results. The scattering lengths and the atom-diatom phase shifts were calcu...

  19. Seasonal shifting of surplus renewable energy in a power system located in a cold region

    Directory of Open Access Journals (Sweden)

    Jorge Morel

    2014-10-01

    Full Text Available The Fukushima nuclear disaster in 2011 changed Japan's strategy for reducing CO2 emissions. The government is now placing more emphasis on the development of nonCO2-emitting distributed generation systems such as wind, solar, and tidal power to reduce greenhouse gas emissions and guarantee electricity supply in the case of a natural disaster. This paper proposes a strategy for the exploitation of wind, solar, and tidal resources in a cold region in Japan by utilizing surplus energy from the summer and spring during winter. It also aims to determine the most favorable energy mix of these renewable sources and storage system types. The study is performed by calculating hourly demand and renewable energy supply for the city in one year, which is based on actual data of demand, solar irradiation, wind speeds, and tidal current speeds. The costs of the components of the renewable power plants and storage systems are considered, and different proportions of generation outputs are evaluated with different types of storage systems. According to results, the configuration containing the hydrogen storage system using organic chemical hydride methylcyclohexane (OCHM is the most economical but is still more expensive than one using a conventional generation system. Moreover, we confirm that the cost of CO2 emissions is the key element for leveling the playing field between conventional and renewable generation from an economic perspective. The cost of CO2 emissions to public health as well as those costs related to the interruption of services during a catastrophe must be carefully calculated with other issues from conventional power projects to perform a precise comparative evaluation between both types of generation systems.

  20. Constraining the gravitational binding energy of PSR J0737-3039B using terrestrial nuclear data

    International Nuclear Information System (INIS)

    We show that the gravitational binding energy of a neutron star of a given mass is correlated with the slope of the nuclear symmetry energy at 1-2 times nuclear saturation density for equations of state without significant softening (i.e., those that predict maximum masses Mmax>1.44M· in line with the largest accurately measured neutron star mass). Applying recent laboratory constraints on the slope of the symmetry energy to this correlation we extract a constraint on the baryon mass of the lower mass member of the double pulsar binary system, PSR J0737-3039B. We compare with independent constraints derived from modeling the progenitor star of J0737-3039B up to and through its collapse under the assumption that it formed in an electron capture supernova. The two sets of constraints are consistent only if L < or approx. 70 MeV.

  1. Hyperon binding energy in Λ6He and Λ7He

    Directory of Open Access Journals (Sweden)

    Filikhin Igor

    2016-01-01

    Full Text Available The three-body approach based on the configuration space Faddeev equations for systems of non-identical particles is proposed to describe light hypernuclei (A=6,7, S=-1 with α particle clustering. We focus on the model (α +Λ + n + n for Λ7He hypernucleus for which the first experimental data have been recently reported. New evaluation for hyperon binding energy in Λ7He is done by using a relation between energies of the spin doublet (1−,2− of Λ6He and the Λ7He ground state. Energies of low-lying levels of Λ6He hypernucleus are calculated within the cluster α + Λ + n model.

  2. Long term energy and emission implications of a global shift to electricity-based public rail transportation system

    International Nuclear Information System (INIS)

    With high reliance on light-duty vehicles in the present, the future of global transportation system is also geared towards private modes, which has significant energy and emission implications. Public transportation has been argued as an alternative strategy for meeting the rising transportation demands of the growing world, especially the poor, in a sustainable and energy efficient way. The present study analyzes an important yet under-researched question – what are the long-term energy and emission implications of an electric rail based passenger transportation system for meeting both long and short distance passenter transportation needs? We analyze a suite of electric rail share scenarios with and without climate policy. In the reference scenario, the transportation system will evolve towards dominance of fossil based light-duty vehicles. We find that an electric rail policy is more successful than an economy wide climate policy in reducing transport sector energy demand and emissions. Economy wide emissions however can only be reduced through a broader climate policy, the cost of which can be reduced by hundreds of billions of dollars across the century when implemented in combination with the transport sector focused electric rail policy. Moreover, higher share of electric rail enhances energy security for oil importing nations and reduces vehicular congestion and road infrastructure requirement as well. -- Highlights: •Economy wide carbon price policy will have little impact on transportation emissions. •Focused energy and emission mitigation policies required for transportation sector. •Large global shift towards electric rail based public transport is one possible option. •Transport sector focused policy will have marginal impact on total global emissions. •A combined transport sector and economy wide policy can reduce costs significantly

  3. Addendum: Triton and hypertriton binding energies calculated from SU_6 quark-model baryon-baryon interactions

    CERN Document Server

    Fujiwara, Y; Kohno, M; Miyagawa, K

    2007-01-01

    Previously we calculated the binding energies of the triton and hypertriton, using an SU_6 quark-model interaction derived from a resonating-group method of two baryon clusters. In contrast to the previous calculations employing the energy-dependent interaction kernel, we present new results using a renormalized interaction, which is now energy independent and reserves all the two-baryon data. The new binding energies are slightly smaller than the previous values. In particular the triton binding energy turns out to be 8.14 MeV with a charge-dependence correction of the two-nucleon force, 190 keV, being included. This indicates that about 350 keV is left for the energy which is to be accounted for by three-body forces.

  4. Benchmark Theoretical Study of the π–π Binding Energy in the Benzene Dimer

    Energy Technology Data Exchange (ETDEWEB)

    Miliordos, Evangelos; Aprà, Edoardo; Xantheas, Sotiris S.

    2014-09-04

    We establish a new estimate for the binding energy between two benzene molecules in the parallel-displaced (PD) conformation by systematically converging (i) the intra- and intermolecular geometry at the minimum, (ii) the expansion of the orbital basis set, and (iii) the level of electron correlation. The calculations were performed at the second-order Møller–Plesset perturbation (MP2) and the coupled cluster including singles, doubles, and a perturbative estimate of triples replacement [CCSD(T)] levels of electronic structure theory. At both levels of theory, by including results corrected for basis set superposition error (BSSE), we have estimated the complete basis set (CBS) limit by employing the family of Dunning’s correlation-consistent polarized valence basis sets. The largest MP2 calculation was performed with the cc-pV6Z basis set (2772 basis functions), whereas the largest CCSD(T) calculation was with the cc-pV5Z basis set (1752 basis functions). The cluster geometries were optimized with basis sets up to quadruple-ζ quality, observing that both its intra- and intermolecular parts have practically converged with the triple-ζ quality sets. The use of converged geometries was found to play an important role for obtaining accurate estimates for the CBS limits. Our results demonstrate that the binding energies with the families of the plain (cc-pVnZ) and augmented (aug-cc-pVnZ) sets converge [within <0.01 kcal/mol for MP2 and <0.15 kcal/mol for CCSD(T)] to the same CBS limit. In addition, the average of the uncorrected and BSSE-corrected binding energies was found to converge to the same CBS limit much faster than either of the two constituents (uncorrected or BSSE-corrected binding energies). Due to the fact that the family of augmented basis sets (especially for the larger sets) causes serious linear dependency problems, the plain basis sets (for which no linear dependencies were found) are deemed as a more efficient and straightforward path for

  5. Computation of binding energies including their enthalpy and entropy components for protein-ligand complexes using support vector machines.

    Science.gov (United States)

    Koppisetty, Chaitanya A K; Frank, Martin; Kemp, Graham J L; Nyholm, Per-Georg

    2013-10-28

    Computing binding energies of protein-ligand complexes including their enthalpy and entropy terms by means of computational methods is an appealing approach for selecting initial hits and for further optimization in early stages of drug discovery. Despite the importance, computational predictions of thermodynamic components have evaded attention and reasonable solutions. In this study, support vector machines are used for developing scoring functions to compute binding energies and their enthalpy and entropy components of protein-ligand complexes. The binding energies computed from our newly derived scoring functions have better Pearson's correlation coefficients with experimental data than previously reported scoring functions in benchmarks for protein-ligand complexes from the PDBBind database. The protein-ligand complexes with binding energies dominated by enthalpy or entropy term could be qualitatively classified by the newly derived scoring functions with high accuracy. Furthermore, it is found that the inclusion of comprehensive descriptors based on ligand properties in the scoring functions improved the accuracy of classification as well as the prediction of binding energies including their thermodynamic components. The prediction of binding energies including the enthalpy and entropy components using the support vector machine based scoring functions should be of value in the drug discovery process.

  6. Anisotropic Lithium Insertion Behavior in Silicon Nanowires: Binding Energy, Diffusion Barrier, and Strain Effect

    KAUST Repository

    Zhang, Qianfan

    2011-05-19

    Silicon nanowires (SiNWs) have recently been shown to be promising as high capacity lithium battery anodes. SiNWs can be grown with their long axis along several different crystallographic directions. Due to distinct atomic configuration and electronic structure of SiNWs with different axial orientations, their lithium insertion behavior could be different. This paper focuses on the characteristics of single Li defects, including binding energy, diffusion barriers, and dependence on uniaxial strain in [110], [100], [111], and [112] SiNWs. Our systematic ab initio study suggests that the Si-Li interaction is weaker when the Si-Li bond direction is aligned close to the SiNW long axis. This results in the [110] and [111] SiNWs having the highest and lowest Li binding energy, respectively, and it makes the diffusion barrier along the SiNW axis lower than other pathways. Under external strain, it was found that [110] and [001] SiNWs are the most and least sensitive, respectively. For diffusion along the axial direction, the barrier increases (decreases) under tension (compression). This feature results in a considerable difference in the magnitude of the energy barrier along different diffusion pathways. © 2011 American Chemical Society.

  7. Observation of a hole-size-dependent energy shift of the surface-plasmon resonance in Ni antidot thin films

    Energy Technology Data Exchange (ETDEWEB)

    Fang, H.; Akinoglu, E. M.; Fumagalli, P., E-mail: paul.fumagalli@fu-berlin.de [Institut für Experimentalphysik, Freie Universität Berlin, 14195 Berlin (Germany); Caballero, B.; García-Martín, A. [IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, Tres Cantos, E-28760 Madrid (Spain); Papaioannou, E. Th. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern (Germany); Cuevas, J. C. [Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Giersig, M. [Institut für Experimentalphysik, Freie Universität Berlin, 14195 Berlin (Germany); Helmholtz Zentrum Berlin, Institute of Nanoarchitectures for Energy Conversion, 14195 Berlin (Germany)

    2015-04-13

    A combined experimental and theoretical study of the magneto-optic properties of a series of nickel antidot thin films is presented. The hole diameter varies from 869 down to 636 nm, while the lattice periodicity is fixed at 920 nm. This results in an overall increase of the polar Kerr rotation with decreasing hole diameter due to the increasing surface coverage with nickel. In addition, at photon energies of 2.7 and 3.3 eV, where surface-plasmon excitations are expected, we observe distinct features in the polar Kerr rotation not present in continuous nickel films. The spectral position of the peaks exhibits a red shift with decreasing hole size. This is explained within the context of an effective medium theory by a change in the effective dielectric function of the Ni thin films.

  8. Novel Moessbauer experiment in a rotating system and the extra-energy shift between emission and absorption lines

    CERN Document Server

    Yarman, T; Arik, M; Akkus, B; Oktem, Y; Susam, L A; Missevitch, O V

    2015-01-01

    We present the results of a novel Mossbauer experiment in a rotating system, implemented recently in Istanbul University, which yields the coefficient k=0.69+/-0.02 within the frame of the expression for the relative energy shift between emission and absorption lines dE/E=ku2/c2. This result turned out to be in a quantitative agreement with an experiment achieved earlier on the subject matter (A.L. Kholmetskii et al. 2009 Phys. Scr. 79 065007), and once again strongly pointed to the inequality k>0.5, revealed originally in (A.L. Kholmetskii et al. 2008 Phys. Scr. 77, 035302 (2008)) via the re-analysis of Kundig experiment (W. Kundig. Phys. Rev. 129, 2371 (1963)). A possible explanation of the deviation of the coefficient k from the relativistic prediction k=0.5 is discussed.

  9. The binding energy of soliton molecules in dispersion-managed optical fibers

    International Nuclear Information System (INIS)

    Solitons in dispersion managed optical fibers can form stable bound states known as soliton molecules. In this work, a mathematical model based on the variational approximation has been proposed, which describes the propagation of soliton molecules in optical fibers. Analytic results are compared with numerical simulation of the nonlinear Schrodinger equation, and qualitative agreement between them is demonstrated. The advantage of the proposed model consists in the possibility to estimate the binding energy of solitons in the molecule and interpretation of the decay of a molecule into separate solitons. The results can be useful in the design of communication systems where optical solitons are employed as carriers of information. (authors)

  10. Fabrication of CuCl quantum dots and the size dependence of the biexciton binding energy

    CERN Document Server

    Park, S T; Kim, H Y; Kim, I G

    2000-01-01

    We fabricated CuCl quantum dots (QDs) in an aluminoborosilicate glass matrix. The photoluminescence of the CuCl QDs was surveyed by using the band-to-band excitation and the site selective luminescence methods. The excitation density dependence of the exciton and the biexciton luminescence was measured, and the saturation effects of the luminescence intensities were observed. The biexciton binding energies measured using the site selective luminescence method increased with decreasing QD size. The data were well fitted by a function resulting from the numerical matrix-diagonalization method.

  11. Folding model analysis of Λ binding energies and three-body ΛNN force

    International Nuclear Information System (INIS)

    Working within the framework of the folding model, we analyze the Λ binding energy data of light hypernuclei with effective two-body ΛN plus three-body ΛNN interaction. The two-body density for the core nucleus required for evaluating the three-body force contribution is obtained in terms of the centre of mass pair correlation. It is found that except for Λ5He the data are fairly well explained. The three-body force seems to account for the density dependence of the effective two-body ΛN interaction proposed earlier. (author). 13 refs, 2 tabs

  12. Pentacycloundecane lactam vs lactone norstatine type protease HIV inhibitors: binding energy calculations and DFT study

    OpenAIRE

    Honarparvar, Bahareh; Pawar, Sachin A; Alves, Cláudio Nahum; Lameira, Jerônimo; Maguire, Glenn EM; José Rogério A. Silva; Govender, Thavendran; Kruger, Hendrik G.

    2015-01-01

    Background Novel pentacycloundecane (PCU)-lactone-CO-EAIS peptide inhibitors were designed, synthesized, and evaluated against wild-type C-South African (C-SA) HIV-1 protease. Three compounds are reported herein, two of which displayed IC50 values of less than 1.00 μM. A comparative MM-PB(GB)SA binding free energy of solvation values of PCU-lactam and lactone models and their enantiomers as well as the PCU-lactam-NH-EAIS and lactone-CO-EAIS peptide inhibitors and their corresponding diastereo...

  13. Evolution of Structure in Nuclei: Meditation by Sub-Shell Modifications and Relation to Binding Energies

    Science.gov (United States)

    Casten, R. F.; Cakirli, R. B.

    2009-03-01

    Understanding the development of configuration mixing, coherence, collectivity, and deformation in nuclei is one of the crucial challenges in nuclear structure physics, and one which has become all the more important with the advent of next generation facilities for the study of exotic nuclei. We will discuss recent work on phase/shape transitional behavior in nuclei, and the role of changes in sub-shell structure in mediating such transitional regions. We will also discuss a newly found, much deeper, link between nuclear structure and nuclear binding energies.

  14. Ab-inito calculation of energy level alignment and vacuum level shift at CuPc/C60 interfaces

    Science.gov (United States)

    Sai, Na; Zhu, Xiaoyang; Chelikowsky, James; Leung, Kevin

    2012-02-01

    The alignment of the donor and acceptor enegy levels is of crucial importance for organic photovotaic performance. We investigate the interfaical electronic structure and energy level alignment of copper phthalocyanine (CuPc)/fullerene (C60) using ab-inito density functional theory calculations including van der Waals interactions and hybrid density functionals. We show that energy level alignment critically depends on the standing-up and lying-down orientation of the CuPc molecules relative to C60 at the interface. We calculate the magnitude of the interface dipole at different molecular orientations and compare them to the vacuum level shift observed in photoemission spectroscopy. The validity of existing theoretical models which invoke charge transfer on this organic interface will be discussed in light of our predictions. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Deparment of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  15. The formation mechanism and the binding energy of the body-centred regular tetrahedral structure of He+5

    Institute of Scientific and Technical Information of China (English)

    李萍; 熊勇; 芶清泉; 张建平

    2002-01-01

    We propose the formation mechanism of the body-centred regular tetrahedral structure of the He+5 cluster. The total energy curve for this structure has been calculated by using a modified arrangement channel quantum mechanics method. The result shows that a minimal energy of -13.9106 a.u. occurs at a separation of 1.14a0 between the nucleus at the centre and nuclei at the apexes. Therefore we obtain the binding energy of 0.5202 a.u. for this structure. This means that the He+5 cluster may be stable with a high binding energy in a body-centred regular tetrahedral structure.

  16. Anomalous center of mass shift gravitational dipole moment

    CERN Document Server

    Jeong, E J

    1996-01-01

    The anomalous, energy dependent shift of the center of mass of an idealized, perfectly rigid, uniformly rotating hemispherical shell which is caused by the relativistic mass increase effect is investigated in detail. It is shown that a classical object on impact which has the harmonic binding force between the adjacent constituent particles has the similar effect of the energy dependent, anomalous shift of the center of mass. From these observations, the general mode of the linear acceleration is suggested to be caused by the anomalous center of mass shift whether it's due to classical or relativistic origin. The effect of the energy dependent center of mass shift perpendicular to the plane of rotation of a rotating hemisphere appears as the non zero gravitational dipole moment in general relativity. Controlled experiment for the measurement of the gravitational dipole field and its possible links to the cylindrical type line formation of a worm hole in the extreme case are suggested. The jets from the black ...

  17. A Thousand Invisible Cords Binding Astronomy and High-Energy Physics

    CERN Document Server

    Kolb, Edward W

    2007-01-01

    The traditional realm of astronomy is the observation and study of the largest objects in the Universe, while the traditional domain of high-energy physics is the study of the smallest things in nature. But these two sciences concerned with opposite ends of the size spectrum are, in Muir's words, bound fast by a thousand invisible cords that cannot be broken. In this essay I propose that collaborations of astronomers and high-energy physicists on common problems are beneficial for both fields, and that both astronomy and high-energy physics can advance by this close and still growing relationship. Dark matter and dark energy are two of the binding cords I will use to illustrate how collaborations of astronomers and high-energy physicists on large astronomical projects can be good for astronomy, and how discoveries in astronomy can guide high-energy physicists in their quest for understanding nature on the smallest scales. Of course, the fields have some different intellectual and collaborative traditions, nei...

  18. Binding energies and scattering observables in the $^{4}He_{3}$ atomic system

    CERN Document Server

    Motovilov, A K; Sofianos, S A; Kolganova, E A

    2001-01-01

    The $^4$He$_3$ bound states and the scattering of a $^4$He atom off a $^4$He dimer at ultra-low energies are investigated using a hard-core version of the Faddeev differential equations. Various realistic $^4$He-$^4$He interactions were employed, amomg them the LM2M2 potential by Aziz and Slaman and the recent TTY potential by Tang, Toennies and Yiu. The ground state and the excited (Efimov) state obtained are compared with other results. The scattering lengths and the atom-diatom phase shifts were calculated for center of mass energies up to 2.45 mK. It was found that the LM2M2 and TTY potentials, although of quite different structure, give practically the same bound-state and scattering results.

  19. Using nonfluorescent Förster resonance energy transfer acceptors in protein binding studies.

    Science.gov (United States)

    Ruan, Qiaoqiao; Skinner, Joseph P; Tetin, Sergey Y

    2009-10-15

    The purpose of this article is to highlight the versatility of nonfluorescent Förster resonance energy transfer (FRET) acceptors in determination of protein equilibrium dissociation constants and kinetic rates. Using a nonfluorescent acceptor eliminates the necessity to spectrally isolate the donor fluorescence when performing binding titrations covering a broad range of reagent concentrations. Moreover, random distribution of the donor and acceptor chromophores on the surface of proteins increases the probability of FRET occurring on their interaction. Three high-affinity antibodies are presented in this study as characteristic protein systems. Monoclonal antibody (mAb) 106.3 binds brain natriuretic peptide (BNP)5-13(C10A) and full-length BNP1-32 with the dissociation constants 0.26+/-0.01 and 0.05+/-0.02 nM, respectively, which was confirmed by kinetic measurements. For anti-hCG (human chorionic gonadotropin) mAb 8F11, studied at two incorporation ratios (IRs=1.9 and 3.8) of the nonfluorescent FRET acceptor, K(D) values of 0.04+/-0.02 and 0.059(-0.004)(+0.006) nM, respectively, were obtained. Likewise, the binding of goat anti-hamster immunoglobulin G (IgG) antibody was not affected by conjugation and yielded K(D) values of 1.26+/-0.04, 1.25+/-0.05, and 1.14+/-0.04 nM at IRs of 1.7, 4.7, and 8.1, respectively. We conclude that this FRET-based method offers high sensitivity, practical simplicity, and versatility in protein binding studies. PMID:19563765

  20. Charge-dependent and A-dependent effects in isotope shifts of Coulomb displacement energies

    International Nuclear Information System (INIS)

    Coulomb displacement energies in a series of isotopes generally decrease with A. This decrease can arise from an increase with A of the average distance of interaction between pairs of protons. In the shell model a decrease can also result from charge-independence-breaking effects if the neutron-proton interaction for the valence nucleons is more attractive than the neutron-neutron interaction. Using the model recently proposed by Sherr and Talmi for the 1d/sub 3/2/ shell, existing data for this shell and also the 1d/sub 5/2/ and 1f/sub 7/2/ shells were analyzed allowing all matrix elements to vary as A/sup -lambda/3/. Least squares calculations of the rms deviation sigma were carried out for varying values of lambda from -2 to +2. It was found that although there was a minimum in sigma vs lambda it was too shallow to exclude any lambda for -1 to +1 in the 1d/sub 3/2/ and 1f/sub 7/2/ shells or 0 to +1 in the 1d/sub 5/2/ shell. It is therefore not possible to distinguish between A dependence and charge dependence in this model. The magnitude of the latter as expressed in terms of (np-nn) matrix elements depends strongly on the former. As lambda increases from -1 to +1, these (np-nn) matrix elements decrease roughly linearly in absolute magnitude and eventually change sign. For lambda = 0 they have appreciable and reasonable magnitudes for the 1d/sub 3/2/ and 1f/sub 7/2/ shells but for the 1d/sub 5/2/ shell the values are too small to be considered significant

  1. On the Binding Energy and the Charge Symmetry Breaking in A<=16 Lambda-hypernuclei

    CERN Document Server

    Botta, E; Feliciello, A

    2016-01-01

    Recent achievements in hypernuclear spectroscopy, in particular the determination of the $\\Lambda$-binding energy B$_{\\Lambda}$ by high precision magnetic spectrometry, contributed to stimulate considerably the search for Charge Symmetry Breaking effects in $\\Lambda$-hypernuclei isomultiplets. We have reorganized the results from the FINUDA experiment and we have produced a list of B$_{\\Lambda}$ values for hypernuclei with A$\\leq$16 considering only the data from magnetic spectrometers with an absolute calibration of the energy scale (FINUDA at DA$\\Phi$NE and electroproduction experiments). By comparing them with the corresponding B$_{\\Lambda}$ from the emulsion experiments, we observe that there is a systematic small difference that is taken into account. A synopsis of all the results on B$_{\\Lambda}$ so far published is finally suggested. Several interesting conclusions are drawn, among which the equality within the errors of B$_{\\Lambda}$ for the A=7, 12, 16 isomultiplets, based only on recent spectrometri...

  2. [Enhanced porcine interferon-alpha production by Pichia pastoris by methanol/sorbitol co-feeding and energy metabolism shift].

    Science.gov (United States)

    Wang, Huihui; Jin, Hu; Gao, Minjie; Dai, Keke; Dong, Shijuan; Yu, Ruisong; Li, Zhen; Shi, Zhongping

    2012-02-01

    Porcine interferon-alpha (pIFN-alpha) fermentative production by recombinant Pichia pastoris was carried out in a 10-L bioreactor to study its metabolism changes and effects on fermentation under different inducing strategies, by analyzing the change patterns of the corresponding metabolism and energy regeneration. The results show that the specific activities of alcohol oxidase (AOX), formaldehyde dehydrogenase (FLD) and formate dehydrogenase (FDH) largely increased when reducing temperature from 30 degrees C to 20 degrees C under pure methanol induction, leading significant enhancements in methanol metabolism, formaldehyde dissimilatory energy metabolism and pIFN-alpha antiviral activity. The highest pIFN-alpha antiviral activity reached 1.4 x 10(6) IU/mL, which was about 10-folds of that obtained under 30 degrees C induction. Using methanol/sorbitol co-feeding strategy at 30 degrees C, the major energy metabolism energizing pIFN-alpha synthesis shifted from formaldehyde dissimilatory energy metabolism pathway to TCA cycle, formaldehyde dissimilatory pathway was weakened and accumulation of toxic intermediate metabolite-formaldehyde was relieved, and methanol flux distribution towards to pIFN-alpha synthesis was enhanced. Under this condition, the highest pIFN-alpha antiviral activity reached 1.8 x 10(7) IU/mL which was about 100-folds of that obtained under pure methanol induction at 30 degrees C. More important, enhanced pIFN-alpha production with methanol/sorbitol co-feeding strategy could be implemented under mild conditions, which greatly reduced the fermentation costs and improved the entire fermentation performance.

  3. Peeling single-stranded DNA from graphite surface to determine oligonucleotide binding energy by force spectroscopy.

    Science.gov (United States)

    Manohar, Suresh; Mantz, Amber R; Bancroft, Kevin E; Hui, Chung-Yuen; Jagota, Anand; Vezenov, Dmitri V

    2008-12-01

    We measured the force required to peel single-stranded DNA molecules from single-crystal graphite using chemical force microscopy. Force traces during retraction of a tip chemically modified with oligonucleotides displayed characteristic plateaus with abrupt force jumps, which we interpreted as a steady state peeling process punctuated by complete detachment of one or more molecules. We were able to differentiate between bases in pyrimidine homopolymers; peeling forces were 85.3 - 4.7 pN for polythymine and 60.8 +/- 5.5 pN for polycytosine, substantially independent of salt concentration and the rate of detachment. We developed a model for peeling a freely jointed chain from the graphite surface and estimated the average binding energy per monomer to be 11.5 +/- 0.6 k(B)T and 8.3 +/- 0.7 k(B)T in the cases of thymine and cytosine nucleotides, respectively. The equilibrium free-energy profile simulated using molecular dynamics had a potential well of 18.9 k(B)T for thymidine, showing that nonelectrostatic interactions dominate the binding. The discrepancy between the experiment and theory indicates that not all bases are adsorbed on the surface or that there is a population of conformations in which they adsorb. Force spectroscopy using oligonucleotides covalently linked to AFM tips provides a flexible and unambiguous means to quantify the strength of interactions between DNA and a number of substrates, potentially including nanomaterials such as carbon nanotubes. PMID:19368004

  4. Chaperone driven polymer translocation through Nanopore: spatial distribution and binding energy

    CERN Document Server

    Abdolvahab, Rouhollah Haji

    2016-01-01

    Chaperones are binding proteins which work as a driving force to bias the biopolymer translocation by binding to it near the pore and preventing its backsliding. Chaperones may have different spatial distribution. Recently we show the importance of their spatial distribution in translocation and how it effects on sequence dependency of the translocation time. Here we focus on homopolymers and exponential distribution. As a result of the exponential distribution of chaperones, energy dependency of the translocation time will changed and one see a minimum in translocation time versus effective energy curve. The same trend can be seen in scaling exponent of time versus polymer length, $\\beta$ ($T\\sim\\beta$). Interestingly in some special cases e.g. chaperones of size $\\lambda=6$ and with exponential distribution rate of $\\alpha=5$, the minimum reaches even to amount of less than $1$ ($\\beta<1$). We explain the possibility of this rare result and base on a theoretical discussion we show that by taking into acc...

  5. Mesoscopic model and free energy landscape for protein-DNA binding sites: analysis of cyanobacterial promoters.

    Directory of Open Access Journals (Sweden)

    Rafael Tapia-Rojo

    2014-10-01

    Full Text Available The identification of protein binding sites in promoter sequences is a key problem to understand and control regulation in biochemistry and biotechnological processes. We use a computational method to analyze promoters from a given genome. Our approach is based on a physical model at the mesoscopic level of protein-DNA interaction based on the influence of DNA local conformation on the dynamics of a general particle along the chain. Following the proposed model, the joined dynamics of the protein particle and the DNA portion of interest, only characterized by its base pair sequence, is simulated. The simulation output is analyzed by generating and analyzing the Free Energy Landscape of the system. In order to prove the capacity of prediction of our computational method we have analyzed nine promoters of Anabaena PCC 7120. We are able to identify the transcription starting site of each of the promoters as the most populated macrostate in the dynamics. The developed procedure allows also to characterize promoter macrostates in terms of thermo-statistical magnitudes (free energy and entropy, with valuable biological implications. Our results agree with independent previous experimental results. Thus, our methods appear as a powerful complementary tool for identifying protein binding sites in promoter sequences.

  6. Effect of magnetic field on the impurity binding energy of the excited states in spherical quantum dot

    Indian Academy of Sciences (India)

    E Sadeghi; Gh Rezaie

    2010-10-01

    The effect of external magnetic field on the excited state energies in a spherical quantum dot was studied. The impurity energy and binding energy were calculated using the variational method within the effective mass approximation and finite barrier potential. The results showed that by increasing the magnetic field, the energy would be increased. The results obtained by this method were compared with the previous investigations.

  7. Risperidone-induced weight gain is mediated through shifts in the gut microbiome and suppression of energy expenditure

    Directory of Open Access Journals (Sweden)

    Sarah M. Bahr

    2015-11-01

    Full Text Available Risperidone is a second-generation antipsychotic that causes weight gain. We hypothesized that risperidone-induced shifts in the gut microbiome are mechanistically involved in its metabolic consequences. Wild-type female C57BL/6J mice treated with risperidone (80 μg/day exhibited significant excess weight gain, due to reduced energy expenditure, which correlated with an altered gut microbiome. Fecal transplant from risperidone-treated mice caused a 16% reduction in total resting metabolic rate in naïve recipients, attributable to suppression of non-aerobic metabolism. Risperidone inhibited growth of cultured fecal bacteria grown anaerobically more than those grown aerobically. Finally, transplant of the fecal phage fraction from risperidone-treated mice was sufficient to cause excess weight gain in naïve recipients, again through reduced energy expenditure. Collectively, these data highlight a major role for the gut microbiome in weight gain following chronic use of risperidone, and specifically implicates the modulation of non-aerobic resting metabolism in this mechanism.

  8. Shifting primary energy source and NOx emission location with plug-in hybrid vehicles

    Science.gov (United States)

    Karman, Deniz

    2011-06-01

    Plug-in hybrid vehicles (PHEVs) present an interesting technological opportunity for using non-fossil primary energy in light duty passenger vehicles, with the associated potential for reducing air pollutant and greenhouse gas emissions, to the extent that the electric power grid is fed by non-fossil sources. This perspective, accompanying the article by Thompson et al (2011) in this issue, will touch on two other studies that are directly related: the Argonne study (Elgowainy et al 2010) and a PhD thesis from Utrecht (van Vliet 2010). Thompson et al (2011) have examined air quality effects in a case where the grid is predominantly fossil fed. They estimate a reduction of 7.42 tons/day of NOx from motor vehicles as a result of substituting electric VMTs for 20% of the light duty gasoline vehicle miles traveled. To estimate the impact of this reduction on air quality they also consider the increases in NOx emissions due to the increased load on electricity generating units. The NOx emission increases are estimated as 4.0, 5.5 and 6.3 tons for the Convenience, Battery and Night charging scenarios respectively. The net reductions are thus in the 1.1-3.4 tons/day range. The air quality modelling results presented show that the air quality impact from a ground-level ozone perspective is favorable overall, and while the effect is stronger in some localities, the difference between the three scenarios is small. This is quite significant and suggests that localization of the NOx emissions to point sources has a more pronounced effect than the absolute reductions achieved. Furthermore it demonstrates that localization of NOx emissions to electricity generating units by using PHEVs in vehicle traffic has beneficial effects for air quality not only by minimizing direct human exposure to motor vehicle emissions, but also due to reduced exposure to secondary pollutants (i.e. ozone). In an electric power grid with a smaller share of fossil fired generating units, the beneficial

  9. Correlating hydrogen oxidation and evolution activity on platinum at different pH with measured hydrogen binding energy

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, WC; Zhuang, ZB; Gao, MR; Zheng, J; Chen, JGG; Yan, YS

    2015-01-08

    The hydrogen oxidation/evolution reactions are two of the most fundamental reactions in distributed renewable electrochemical energy conversion and storage systems. The identification of the reaction descriptor is therefore of critical importance for the rational catalyst design and development. Here we report the correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH from 0 to 13. The hydrogen oxidation/evolution activity obtained using the rotating disk electrode method is found to decrease with the pH, while the hydrogen binding energy, obtained from cyclic voltammograms, linearly increases with the pH. Correlating the hydrogen oxidation/evolution activity to the hydrogen binding energy renders a monotonic decreasing hydrogen oxidation/evolution activity with the hydrogen binding energy, strongly supporting the hypothesis that hydrogen binding energy is the sole reaction descriptor for the hydrogen oxidation/evolution activity on monometallic platinum.

  10. Correlating hydrogen oxidation and evolution activity on platinum at different pH with measured hydrogen binding energy

    Science.gov (United States)

    Sheng, Wenchao; Zhuang, Zhongbin; Gao, Minrui; Zheng, Jie; Chen, Jingguang G.; Yan, Yushan

    2015-01-01

    The hydrogen oxidation/evolution reactions are two of the most fundamental reactions in distributed renewable electrochemical energy conversion and storage systems. The identification of the reaction descriptor is therefore of critical importance for the rational catalyst design and development. Here we report the correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH from 0 to 13. The hydrogen oxidation/evolution activity obtained using the rotating disk electrode method is found to decrease with the pH, while the hydrogen binding energy, obtained from cyclic voltammograms, linearly increases with the pH. Correlating the hydrogen oxidation/evolution activity to the hydrogen binding energy renders a monotonic decreasing hydrogen oxidation/evolution activity with the hydrogen binding energy, strongly supporting the hypothesis that hydrogen binding energy is the sole reaction descriptor for the hydrogen oxidation/evolution activity on monometallic platinum.

  11. Shifting Attention

    Science.gov (United States)

    Ingram, Jenni

    2014-01-01

    This article examines the shifts in attention and focus as one teacher introduces and explains an image that represents the processes involved in a numeric problem that his students have been working on. This paper takes a micro-analytic approach to examine how the focus of attention shifts through what the teacher and students do and say in the…

  12. Decipher the mechanisms of protein conformational changes induced by nucleotide binding through free-energy landscape analysis: ATP binding to Hsp70.

    Directory of Open Access Journals (Sweden)

    Adrien Nicolaï

    Full Text Available ATP regulates the function of many proteins in the cell by transducing its binding and hydrolysis energies into protein conformational changes by mechanisms which are challenging to identify at the atomic scale. Based on molecular dynamics (MD simulations, a method is proposed to analyze the structural changes induced by ATP binding to a protein by computing the effective free-energy landscape (FEL of a subset of its coordinates along its amino-acid sequence. The method is applied to characterize the mechanism by which the binding of ATP to the nucleotide-binding domain (NBD of Hsp70 propagates a signal to its substrate-binding domain (SBD. Unbiased MD simulations were performed for Hsp70-DnaK chaperone in nucleotide-free, ADP-bound and ATP-bound states. The simulations revealed that the SBD does not interact with the NBD for DnaK in its nucleotide-free and ADP-bound states whereas the docking of the SBD was found in the ATP-bound state. The docked state induced by ATP binding found in MD is an intermediate state between the initial nucleotide-free and final ATP-bound states of Hsp70. The analysis of the FEL projected along the amino-acid sequence permitted to identify a subset of 27 protein internal coordinates corresponding to a network of 91 key residues involved in the conformational change induced by ATP binding. Among the 91 residues, 26 are identified for the first time, whereas the others were shown relevant for the allosteric communication of Hsp70 s in several experiments and bioinformatics analysis. The FEL analysis revealed also the origin of the ATP-induced structural modifications of the SBD recently measured by Electron Paramagnetic Resonance. The pathway between the nucleotide-free and the intermediate state of DnaK was extracted by applying principal component analysis to the subset of internal coordinates describing the transition. The methodology proposed is general and could be applied to analyze allosteric communication in

  13. Mechanical function of two ankle extensors in wild turkeys: shifts from energy production to energy absorption during incline versus decline running.

    Science.gov (United States)

    Gabaldón, Annette M; Nelson, Frank E; Roberts, Thomas J

    2004-06-01

    (-1) of net work in stance and the PL absorbed 2.4+/-0.9 J kg(-1) of net work. Shifts in muscle mechanical function from energy production during incline running to energy absorption during decline running were observed over a range of running speeds from 1-3 m s(-1) for both the LG and PL. Two fundamentally different mechanisms for changing work output were apparent in the mechanical behavior of the LG and PL. The LG simply altered its length pattern; it actively shortened during incline running to produce mechanical energy and actively lengthened during decline running to absorb mechanical energy. The PL changed mechanical function by altering its length pattern and by shifting the timing of force production across its stretch-shorten cycle. During incline running, the PL produced force during late stance shortening for positive work, but during decline running, the timing of force production shifted into early stance, to align with lengthening for negative work. In addition, during decline running, the PL greatly reduced or eliminated late stance shortening, thus reducing the potential for positive work. Our results show that the changing demands for whole body work during steady speed running are met, at least in part, by an ability of single muscles to shift mechanical function from net energy production to net energy absorption.

  14. Quantum mechanical treatment of binding energy between DNA nucleobases and carbon nanotube: A DFT analysis

    Science.gov (United States)

    Chehel Amirani, Morteza; Tang, Tian; Cuervo, Javier

    2013-12-01

    The interactions between DNA and carbon nanotubes (CNTs) have been widely studied in recent years. The binding process of DNA with CNT as well as the electronic properties of DNA/CNT hybrids constitutes an interesting yet complicated problem. The binding energy (BE) of the hybridization is one of the most extensively studied parameters for the problem. In this work, density functional theory (DFT) was used to perform geometry optimization of neutral nucleobases including adenine, cytosine, guanine and thymine absorbed on a zigzag (7,0) single-walled CNT and to evaluate the basis set superposition error corrected BE of the optimized configuration. All DFT calculations were performed using the M05-2X functional. The 6-31G(d) basis set was used for the optimization step and single point energy calculations were done using the 6-31G(d,p) basis set. For each nucleobase, we examined the influence of the initial configuration (IC) on the BE value. In particular, we considered 24 different ICs for each nucleobase, and each IC was subjected to an independent optimization and BE calculation. Our results showed that different ICs result in very different BE values and can even change the order of the BE corresponding to different nucleobases. The difference in the BE for a particular nucleobase caused by changes in its IC can be comparable to the difference in the BE between different nucleobases at the same initial position relative to the CNT. This provides an explanation for the discrepancies that exist in the literature on the nucleobase/CNT BE, and suggests that the potential energy surface between the nucleobases and the CNT can have many local minima and care should be exercised in the calculation and interpretation of the BE.

  15. The impacts of electronic state hybridization on the binding energy of single phosphorus donor electrons in extremely downscaled silicon nanostructures

    Science.gov (United States)

    The Anh, Le; Moraru, Daniel; Manoharan, Muruganathan; Tabe, Michiharu; Mizuta, Hiroshi

    2014-08-01

    We present the density functional theory calculations of the binding energy of the Phosphorus (P) donor electrons in extremely downscaled single P-doped Silicon (Si) nanorods. In past studies, the binding energy of donor electrons was evaluated for the Si nanostructures as the difference between the ionization energy for the single P-doped Si nanostructures and the electron affinity for the un-doped Si nanostructures. This definition does not take into account the strong interaction of donor electron states and Si electron states explicitly at the conductive states and results in a monotonous increase in the binding energy by reducing the nanostructure's dimensions. In this paper, we introduce a new approach to evaluate the binding energy of donor electrons by combining the projected density of states (PDOS) analysis and three-dimensional analysis of associated electron wavefunctions. This enables us to clarify a gradual change of the spatial distribution of the 3D electron wavefunctions (3DWFs) from the donor electron ground state, which is fully localized around the P donor site to the first conductive state, which spreads over the outer Si nanorods contributing to current conduction. We found that the energy of the first conductive state is capped near the top of the atomistic effective potential at the donor site with respect to the surrounding Si atoms in nanorods smaller than about 27 a0. This results in the binding energy of approximately 1.5 eV, which is virtually independent on the nanorod's dimensions. This fact signifies a good tolerance of the binding energy, which governs the operating temperature of the single dopant-based transistors in practice. We also conducted the computationally heavy transmission calculations of the single P-doped Si nanorods connected to the source and drain electrodes. The calculated transmission spectra are discussed in comparison with the atomistic effective potential distributions and the PDOS-3DWFs method.

  16. Calculation of absolute free energy of binding for theophylline and its analogs to RNA aptamer using nonequilibrium work values

    OpenAIRE

    Tanida, Yoshiaki; Ito, Masakatsu; Fujitani, Hideaki

    2007-01-01

    The massively parallel computation of absolute binding free energy with a well-equilibrated system (MP-CAFEE) has been developed [H. Fujitani, Y. Tanida, M. Ito, G. Jayachandran, C. D. Snow, M. R. Shirts, E. J. Sorin, and V. S. Pande, J. Chem. Phys. ${\\bf 123}$, 084108 (2005)]. As an application, we perform the binding affinity calculations of six theophylline-related ligands with RNA aptamer. Basically, our method is applicable when using many compute nodes to accelerate simulations, thus a ...

  17. Relativistic many-body calculation of energies, lifetimes, polarizabilities, blackbody radiative shift and hyperfine constants in Lu2+

    CERN Document Server

    Safronova, U I; Johnson, W R

    2016-01-01

    Energy levels of 30 low-lying states of Lu2+ and allowed electric-dipole matrix elements between these states are evaluated using a relativistic all-order method in which all single, double and partial triple excitations of Dirac-Fock wave functions are included to all orders of perturbation theory. Matrix elements are critically evaluated for their accuracy and recommended values of the matrix elements are given together with uncertainty estimates. Line strengths, transition rates and lifetimes of the metastable 5d(3/2) and 5d(5/2) states are calculated. Recommended values are given for static polarizabilities of the 6s, 5d and 6p states and tensor polarizabilities of the 5d and 6p(3/2) states. Uncertainties of the polarizability values are estimated in all cases. The blackbody radiation shift of the 6s(1/2)-5d(5/2) transition frequency of the Lu2+ ion is calculated with the aid of the recommended scalar polarizabilities of the 6s(1/2) and 5d(5/2) states. Finally, A and B hyperfine constants are determined f...

  18. Relativistic many-body calculation of energies, lifetimes, polarizabilities, blackbody radiative shift, and hyperfine constants in Lu2 +

    Science.gov (United States)

    Safronova, U. I.; Safronova, M. S.; Johnson, W. R.

    2016-09-01

    Energy levels of 30 low-lying states of Lu2 + and allowed electric-dipole matrix elements between these states are evaluated using a relativistic all-order method in which all single, double, and partial triple excitations of Dirac-Fock wave functions are included to all orders of perturbation theory. Matrix elements are critically evaluated for their accuracy and recommended values of the matrix elements are given together with uncertainty estimates. Line strengths, transition rates, and lifetimes of the metastable 5 d3 /2 and 5 d5 /2 states are calculated. Recommended values are given for static polarizabilities of the 6 s , 5 d , and 6 p states and tensor polarizabilities of the 5 d and 6 p3 /2 states. Uncertainties of the polarizability values are estimated in all cases. The blackbody radiation shift of the 6 s1 /2-5 d5 /2 transition frequency of the Lu2 + ion is calculated with the aid of the recommended scalar polarizabilities of the 6 s1 /2 and 5 d5 /2 states. Finally, A and B hyperfine constants are determined for states of 2+175Lu with n ≤9 . This work provides recommended values of transition matrix elements, polarizabilities, and hyperfine constants of Lu2 +, critically evaluated for accuracy, for benchmark tests of high-precision theoretical methodology and planning of future experiments.

  19. Effect of dense plasmas on exchange-energy shifts in highly charged ions: An alternative approach for arbitrary perturbation potentials

    Energy Technology Data Exchange (ETDEWEB)

    Rosmej, F. [Sorbonne Universites, Pierre et Marie Curie, UMR 7605, case 128, 4 place Jussieu, F-75252 Paris (France); Ecole Polytechnique, Laboratoire pour l' Utilisation des Lasers Intenses LULI, Physique Atomique dans les Plasmas Denses PAPD, F-91228 Palaiseau (France); Bennadji, K. [Sorbonne Universites, Pierre et Marie Curie, UMR 7605, case 128, 4 place Jussieu, F-75252 Paris (France); ExtreMe Matter Institute EMMI, GSI Helmholtz Centre of Heavy Ion Research, Planckstrasse 1, D-64291 Darmstadt (Germany); Lisitsa, V. S. [Russian Research Center Kurchatov, Laboratory of Radiation Theory, Kurchatov Square 1, 123182 Moscow (Russian Federation)

    2011-09-15

    An alternative method of calculation of dense plasma effects on exchange-energy shifts {Delta}E{sub x} of highly charged ions is proposed which results in closed expressions for any plasma or perturbation potential. The method is based on a perturbation theory expansion for the inner atomic potential produced by charged plasma particles employing the Coulomb Green function method. This approach allows us to obtain analytic expressions and scaling laws with respect to the electron temperature T, density n{sub e}, and nuclear charge Z. To demonstrate the power of the present method, two specific models were considered in detail: the ion sphere model (ISM) and the Debye screening model (DSM). We demonstrate that analytical expressions can be obtained even for the finite temperature ISM. Calculations have been carried out for the singlet 1s2p{sup 1} P{sub 1} and triplet 1s2p{sup 3} P{sub 1} configurations of He-like ions with charge Z that can be observed in dense plasmas via the He-like resonance and intercombination lines. Finally we discuss recently available purely numerical calculations and experimental data.

  20. Orbital momentum distributions and binding energies for the complete valence shell of molecular iodine

    International Nuclear Information System (INIS)

    The complete valence shell binding energy spectrum (8-43eV) of I2 has been measured by using electron momentum spectroscopy at 1000eV. The complete inner valence region, corresponding to ionization from the 10 σu and 10 σg orbitals, has been measured for the first time and shows extensive splitting of the ionization strength due to electron correlation effects in the ion. Many-body calculations using the Green's function method have been carried out and are compared with the data. Momentum distributions, measured in both the outer and inner valence regions, are compared with those given by SCF orbital wave functions calculated with a number of different basis sets. Computed orbital position and momentum density maps for oriented I2 molecules are discussed in comparison with the measured and calculated spherically averaged momentum distributions

  1. Exciton binding energies and absorption in intermixed GaAs-AlGaAs quantum wells

    Science.gov (United States)

    Meney, Alistair T.

    1992-12-01

    The optical properties of excitons in layer-intermixed GaAs-AlGaAs quantum wells are studied theoretically. The electronic dispersion is obtained using the 6×6 Luttinger-Kohn Hamiltonian for the valence bands, and an accurate expression for the conduction band dispersion which includes the effects of nonparabolicity and warping to fourth order in k. The HH1-CB1 (1s) and LH1-CB1(1s) exciton binding energies are calculated as a function of diffusion time. The absorption for both TE and TM polarization is obtained at several wavelengths, and is seen to decrease significantly with increased intermixing. The decrease in absorption is larger for narrow wells, where the effects of intermixing are more pronounced for a given diffusion time.

  2. Spin assignments of nuclear levels above the neutron binding energy in $^{88}$Sr

    CERN Multimedia

    Neutron resonances reveal nuclear levels in the highly excited region of the nucleus around the neutron binding energy. Nuclear level density models are therefore usually calibrated to the number of observed levels in neutron-induced reactions. The gamma-ray cascade from the decay of the highly excited compound nucleus state to the ground state show dierences dependent on the initial spin. This results in a dierence in the multiplicity distribution which can be exploited. We propose to use the 4${\\pi}$ total absorption calorimeter (TAC) at the n TOF facility to determine the spins of resonances formed by neutrons incident on a metallic $^{87}$Sr sample by measuring the gamma multiplicity distributions for the resolved resonances. In addition we would like to use the available enriched $^{87}$Sr target for cross section measurements with the C$\\scriptscriptstyle{6}$D$\\scriptscriptstyle{6}$ detector setup.

  3. Role of Codeposited Impurities in Growth: Dependence of Morphology on Binding and Barrier Energies

    Science.gov (United States)

    Sathiyanarayanan, Rajesh; Hamouda, A. Bh.; Pimpinelli, A.; Einstein, T. L.

    2010-03-01

    The previous talk showed that codeposition of impurity atoms during epitaxial growth could be used for nanostructuring of surfaces. Based on their lateral nearest-neighbor binding energies (ENN) to Cu and their diffusion barriers (Ed) on Cu(001), we classify the candidate impurity atoms into four sets. We find that codeposition of impurities from different sets produce qualitatively different surface morphologies both in the step-flow and the submonolayer (θ<= 0.7 ML) regimes. In the submonolayer regime, we characterize these differences through variations of the number of islands (Ni) and the average island size with coverage (θ). Further, we compute the critical nucleus size (i) for all of these cases from the distribution of capture-zone areas using the generalized Wigner distribution.footnotetextA. Pimpinelli, T. L. Einstein, Phys. Rev. Lett. 99, 226102 (2007).

  4. Mechanical Control of ATP Synthase Function: Activation Energy Difference between Tight and Loose Binding Sites

    KAUST Repository

    Beke-Somfai, Tamás

    2010-01-26

    Despite exhaustive chemical and crystal structure studies, the mechanistic details of how FoF1-ATP synthase can convert mechanical energy to chemical, producing ATP, are still not fully understood. On the basis of quantum mechanical calculations using a recent highresolution X-ray structure, we conclude that formation of the P-O bond may be achieved through a transition state (TS) with a planar PO3 - ion. Surprisingly, there is a more than 40 kJ/mol difference between barrier heights of the loose and tight binding sites of the enzyme. This indicates that even a relatively small change in active site conformation, induced by the γ-subunit rotation, may effectively block the back reaction in βTP and, thus, promote ATP. © 2009 American Chemical Society.

  5. Binding energy of one [sup 4]He impurity in liquid [sup 3]He

    Energy Technology Data Exchange (ETDEWEB)

    Boronat, J. (Universitat Politecnica de Catalunya, Barcelona (Spain)); Saavedra, F.A. de; Buendia, E. (Universidad de Granola (Spain)); Polls, A. (Universitat de Barcelona (Spain))

    1994-02-01

    A variational microscopic calculation of the binding energy of a [sup 4]He impurity ([mu][sub I]) in homogeneous liquid [sup 3]He at zero temperature is presented. Starting on an extended Jastrow-Slater wave function including three-body correlations, the expression for [mu][sub I] is derived and the appropriated FHNC formalism for this problem is reviewed. In the framework of the Average Correlation Approximation (ACA), it is proved that it is possible to obtain the chemical potential of the impurity only from liquid [sup 3]He magnitudes with a good accuracy. The results are consistent with both a recent experimental determination of [mu][sub I] at zero pressure and the non-solubility of [sup 4]He in [sup 3]He. However, numerical uncertainties preclude a firm conclusion about the latter property.

  6. Experimental determination of the deuterium binding energy with vacancies in tungsten

    Science.gov (United States)

    Zibrov, M.; Ryabtsev, S.; Gasparyan, Yu.; Pisarev, A.

    2016-08-01

    Deuterium (D) interaction with vacancies in tungsten (W) was studied using thermal desorption spectroscopy (TDS). In order to obtain a TDS spectrum with a prominent peak corresponding to D release from vacancies, a special procedure comprising damaging of a recrystallized W sample by low fluences of 10 keV/D ions, its annealing, and subsequent low-energy ion implantation, was utilized. This experimental sequence was performed several times in series; the only difference was the TDS heating rate that varied in the range of 0.15-4 K/s. The sum of the D binding energy (Eb) with vacancies and the activation energy for D diffusion (ED) in W was then directly determined from the slope of the Arrhenius-like plot ln(β / Tm2) versus 1/Tm, where β - heating rate and Tm - position of the respective peak in the TDS spectrum. The determined value of Eb + ED was 1.56 ± 0.06 eV.

  7. State vector evolution localized over the edges of a square tight-binding lattice

    Institute of Scientific and Technical Information of China (English)

    He Liang-Ming; Shi Duan-Wen

    2009-01-01

    We study the time evolution of a state vector in a square tight-binding lattice, focusing on its evolution localized over the system surfaces. In this tight-binding lattice, the energy of atomic orbital centred at surface site is different from that at the interior (bulky) site by an energy shift U. It is shown that for the state vector initially localized on a surface, there exists an exponential law (y = aex/b + yo) determined by the absolute value of the energy shift, \\U\\, which describes the transition of the state evolving on the square tight-binding lattice, from delocalized over the whole lattice to localized over the surfaces.

  8. Surface core-level shifts for Ge(100)-(2 x 1)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, T.; Rosenwinkel, E.; Chiang, T.C.

    1983-01-01

    Using surface-sensitive photoemission techniques, Ge 3d core-level binding energies for surface atoms of Ge(100)-(2 x 1) are found to be smaller than the bulk values by 0.41 eV. The surface atoms with shifted core-level binding energies correspond to one full (100) atomic layer. A surface core-exciton resonance is observed in the partial-yield measurements. The empty surface state involved in this excitonic transition, without binding-energy correction, is located at the valence-band maximum. 14 references, 2 figures, 1 table.

  9. Surface core-level shifts for Ge(100)-(2 x 1)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, T.; Rosenwinkel, E.; Chiang, T.C.

    1983-01-01

    Using surface-sensitive photoemission techniques, Ge 3d core-level binding energies for surface atoms of Ge(100)-(2 x 1) are found to be smaller than the bulk values by 0.41 eV. The surface atoms with shifted core-level binding energies correspond to one full (100) atomic layer. A surface core-exciton resonance is observed in the partial-yield measurements. The empty surface state involved in this excitonic transition, without binding-energy correction, is located at the valence-band maximum.

  10. Effects of Crossed Electric and Magnetic Fields on Shallow Donor Impurity Binding Energy in a Parabolic Quantum Well

    Institute of Scientific and Technical Information of China (English)

    E. Kasapoglu; H. Sari; I. S(o)kmen

    2004-01-01

    @@ We have calculated variationally the ground state binding energy of a hydrogenic donor impurity in a parabolic quantum well in the presence of crossed electric and magnetic fields. These homogeneous crossed fields are such that the magnetic field is parallel to the heterostructure layers and the electric field is applied perpendicular to the magnetic field. The dependence of the donor impurity binding energy to the well width and the strength of the electric and magnetic fields are discussed. We hope that the obtained results will provide important improvements in device applications, especially for a suitable choice of both fields in the narrow well widths.

  11. Computational prediction of binding affinity for CYP1A2-ligand complexes using empirical free energy calculations

    DEFF Research Database (Denmark)

    Poongavanam, Vasanthanathan; Olsen, Lars; Jørgensen, Flemming Steen;

    2010-01-01

    , and methods based on statistical mechanics. In the present investigation, we started from an LIE model to predict the binding free energy of structurally diverse compounds of cytochrome P450 1A2 ligands, one of the important human metabolizing isoforms of the cytochrome P450 family. The data set includes both...... substrates and inhibitors. It appears that the electrostatic contribution to the binding free energy becomes negligible in this particular protein and a simple empirical model was derived, based on a training set of eight compounds. The root mean square error for the training set was 3.7 kJ/mol. Subsequent...

  12. Accuracy of predictive equations for resting metabolic rates and daily energy expenditures of police officials doing shift work by type of work.

    Science.gov (United States)

    Lee, Sun Hee; Kim, Eun Kyung

    2012-07-01

    The purpose of this study was to analyze the accuracy of predictive equations for resting metabolic rate (RMR) and daily energy expenditure in policemen on a rotating shift. Subjects were 28 healthy policemen on a rotating shift (males) age of 23-46 years. The participants' RMR was measured by using indirect calorimetry (TrueOne2400) and also calculated from various predicted equations of RMR (Harris-Benedict, Schofield(W)/(WH), FAO/WHO/UNU(W)/(W/H), Cunningham, Mifflin, Liu, Owen, IMNA and Henry(W)/(WH)). The accuracy of these equations were evaluated on basis of accurate prediction (the percentage of subjects whose RMR was predicted within 90% to 110% of the RMR measured), mean difference, root mean squared prediction error, mean % difference, limits of agreement of Bland-Altman method between predicted and measured RMR. The measured RMR value of subjects was 1748 ± 205.9 kcal. Of the predictive equations tested, the Harris-Benedict equation (mean difference: -14.8 kcal/day, RMSPE: 195.8 kcal/day, mean % difference: 0.1%) was the most accurate and precise, but accuracy in prediction of the equation were only 35.7%. The daily energy expenditure at night-duty was 3062 kcal calculated as multiplying RMR by its physical activity level. Subsequently, daily energy expenditure of day-duty was 2647 kcal and the lowest daily energy expenditure was, 2310 kcal at holiday duty. Daily energy intake of all study participants was 2351 kcal at day-duty, 1959 kcal at night-duty and 1796 kcal at holiday-duty in order. The estimated energy requirements for policemen on a rotating shift on day shift, night shift and holiday came to 2743.6 kcal/day, 2998.6 kcal/day and 2576.9 kcal/day, respectively. These results suggest that estimated energy requirements (EER) of policemen on a rotating shift should be differently proposed by a proper equation which can closely reflect their metabolic status at each time shift. PMID:23429979

  13. Optimizing the Binding Energy of Hydrogen on Nanostructured Carbon Materials through Structure Control and Chemical Doping

    Energy Technology Data Exchange (ETDEWEB)

    Jie Liu

    2011-02-01

    The DOE Hydrogen Sorption Center of Excellence (HSCoE) was formed in 2005 to develop materials for hydrogen storage systems to be used in light-duty vehicles. The HSCoE and two related centers of excellence were created as follow-on activities to the DOE Office of Energy Efficiency and Renewable Energy’s (EERE’s) Hydrogen Storage Grand Challenge Solicitation issued in FY 2003. The Hydrogen Sorption Center of Excellence (HSCoE) focuses on developing high-capacity sorbents with the goal to operate at temperatures and pressures approaching ambient and be efficiently and quickly charged in the tank with minimal energy requirements and penalties to the hydrogen fuel infrastructure. The work was directed at overcoming barriers to achieving DOE system goals and identifying pathways to meet the hydrogen storage system targets. To ensure that the development activities were performed as efficiently as possible, the HSCoE formed complementary, focused development clusters based on the following four sorption-based hydrogen storage mechanisms: 1. Physisorption on high specific surface area and nominally single element materials 2. Enhanced H2 binding in Substituted/heterogeneous materials 3. Strong and/or multiple H2 binding from coordinated but electronically unsatruated metal centers 4. Weak Chemisorption/Spillover. As a member of the team, our group at Duke studied the synthesis of various carbon-based materials, including carbon nanotubes and microporous carbon materials with controlled porosity. We worked closely with other team members to study the effect of pore size on the binding energy of hydrogen to the carbon –based materials. Our initial project focus was on the synthesis and purification of small diameter, single-walled carbon nanotubes (SWNTs) with well-controlled diameters for the study of their hydrogen storage properties as a function of diameters. We developed a chemical vapor deposition method that synthesized gram quantities of carbon nanotubes with

  14. Probing Difference in Binding Modes of Inhibitors to MDMX by Molecular Dynamics Simulations and Different Free Energy Methods.

    Directory of Open Access Journals (Sweden)

    Shuhua Shi

    Full Text Available The p53-MDMX interaction has attracted extensive attention of anti-cancer drug development in recent years. This current work adopted molecular dynamics (MD simulations and cross-correlation analysis to investigate conformation changes of MDMX caused by inhibitor bindings. The obtained information indicates that the binding cleft of MDMX undergoes a large conformational change and the dynamic behavior of residues obviously change by the presence of different structural inhibitors. Two different methods of binding free energy predictions were employed to carry out a comparable insight into binding mechanisms of four inhibitors PMI, pDI, WK23 and WW8 to MDMX. The data show that the main factor controlling the inhibitor bindings to MDMX arises from van der Waals interactions. The binding free energies were further divided into contribution of each residue and the derived information gives a conclusion that the hydrophobic interactions, such as CH-CH, CH-π and π-π interactions, are responsible for the inhibitor associations with MDMX.

  15. Probing Difference in Binding Modes of Inhibitors to MDMX by Molecular Dynamics Simulations and Different Free Energy Methods.

    Science.gov (United States)

    Shi, Shuhua; Zhang, Shaolong; Zhang, Qinggang

    2015-01-01

    The p53-MDMX interaction has attracted extensive attention of anti-cancer drug development in recent years. This current work adopted molecular dynamics (MD) simulations and cross-correlation analysis to investigate conformation changes of MDMX caused by inhibitor bindings. The obtained information indicates that the binding cleft of MDMX undergoes a large conformational change and the dynamic behavior of residues obviously change by the presence of different structural inhibitors. Two different methods of binding free energy predictions were employed to carry out a comparable insight into binding mechanisms of four inhibitors PMI, pDI, WK23 and WW8 to MDMX. The data show that the main factor controlling the inhibitor bindings to MDMX arises from van der Waals interactions. The binding free energies were further divided into contribution of each residue and the derived information gives a conclusion that the hydrophobic interactions, such as CH-CH, CH-π and π-π interactions, are responsible for the inhibitor associations with MDMX. PMID:26513747

  16. Predicting Binding Free Energy Change Caused by Point Mutations with Knowledge-Modified MM/PBSA Method.

    Directory of Open Access Journals (Sweden)

    Marharyta Petukh

    2015-07-01

    Full Text Available A new methodology termed Single Amino Acid Mutation based change in Binding free Energy (SAAMBE was developed to predict the changes of the binding free energy caused by mutations. The method utilizes 3D structures of the corresponding protein-protein complexes and takes advantage of both approaches: sequence- and structure-based methods. The method has two components: a MM/PBSA-based component, and an additional set of statistical terms delivered from statistical investigation of physico-chemical properties of protein complexes. While the approach is rigid body approach and does not explicitly consider plausible conformational changes caused by the binding, the effect of conformational changes, including changes away from binding interface, on electrostatics are mimicked with amino acid specific dielectric constants. This provides significant improvement of SAAMBE predictions as indicated by better match against experimentally determined binding free energy changes over 1300 mutations in 43 proteins. The final benchmarking resulted in a very good agreement with experimental data (correlation coefficient 0.624 while the algorithm being fast enough to allow for large-scale calculations (the average time is less than a minute per mutation.

  17. Computation of relative binding free energy for an inhibitor and its analogs binding with Erk kinase using thermodynamic integration MD simulation.

    Science.gov (United States)

    Wu, Kuan-Wei; Chen, Po-Chin; Wang, Jun; Sun, Ying-Chieh

    2012-10-01

    In the present study, we carried out thermodynamic integration molecular dynamics simulation for a pair of analogous inhibitors binding with Erk kinase to investigate how computation performs in reproducing the relative binding free energy. The computation with BCC-AM1 charges for ligands gave -1.1 kcal/mol, deviated from experimental value of -2.3 kcal/mol by 1.2 kcal/mol, in good agreement with experimental result. The error of computed value was estimated to be 0.5 kcal/mol. To obtain convergence, switching vdw interaction on and off required approximately 10 times more CPU time than switching charges. Residue-based contributions and hydrogen bonding were analyzed and discussed. Furthermore, subsequent simulation using RESP charge for ligand gave ΔΔG of -1.6 kcal/mol. The computed results are better than the result of -5.6 kcal/mol estimated using PBSA method in a previous study. Based on these results, we further carried out computations to predict ΔΔG for five new analogs, focusing on placing polar and nonpolar functional groups at the meta site of benzene ring shown in the Fig. 1, to see if these ligands have better binding affinity than the above ligands. The computations resulted that a ligand with polar -OH group has better binding affinity than the previous examined ligand by ~2.0 kcal/mol and two other ligands have better affinity by ~1.0 kcal/mol. The predicted better inhibitors of this kind should be of interest to experimentalist for future experimental enzyme and/or cell assays. PMID:22986633

  18. Role of codeposited impurities during growth. II. Dependence of morphology on binding and barrier energies

    Science.gov (United States)

    Sathiyanarayanan, Rajesh; Hamouda, Ajmi Bh.; Pimpinelli, A.; Einstein, T. L.

    2011-01-01

    In an accompanying article we showed that surface morphologies obtained through codeposition of a small quantity (2%) of impurities with Cu during growth (step-flow mode, θ = 40 ML) significantly depends on the lateral nearest-neighbor binding energy (ENN) to Cu adatom and the diffusion barrier (Ed) of the impurity atom on Cu(0 0 1). Based on these two energy parameters, ENN and Ed, we classify impurity atoms into four sets. We study island nucleation and growth in the presence of codeposited impurities from different sets in the submonolayer (θ⩽ 0.7 ML) regime. Similar to growth in the step-flow mode, we find different nucleation and growth behavior for impurities from different sets. We characterize these differences through variations of the number of islands (Ni) and the average island size with coverage (θ). Further, we compute the critical nucleus size (i) for all of these cases from the distribution of capture-zone areas using the generalized Wigner distribution.

  19. Binding energies of the lithium isoelectronic sequence approaching the critical charge

    Science.gov (United States)

    Katriel, Jacob; Puchalski, Mariusz; Pachucki, Krzysztof

    2012-10-01

    The Simon-Zhislin-Hunziker theorem implies that Zc, the critical charge below which the three electron atom is not bound, is at most 2. The vanishing electron affinity of He implies that Zc is not less than 2. Hence, Zc=2. To elucidate the approach to the critical charge, we calculated nonrelativistic binding energies for the third electron in the ground state, 1s22s2S, and in the first and second excited states, 1s22p2P and 1s23s2S, for nuclear charges approaching Zc. At this limit the quantum defects for both 2S states are found to approach unity. This implies that the orbital specifying the outer (ns,n=2,3) electron becomes a very diffuse (n-1)s-type orbital, except within the relatively tiny space occupied by the inner two-electron shell. For the 2P state the quantum defect approaches zero both as Z→∞ and as Z→2. An expression for the s-p splitting at Z→2 is suggested, that improves upon earlier results based on energies computed (or measured) at integer values of Z. Rigorous large Z asymptotic expressions for the quantum defects in the 1s2ns2S states are presented, exhibiting the expected mild dependence on the principal quantum number.

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

    Science.gov (United States)

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

    2014-03-01

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

  1. Identification of DNA-binding protein target sequences by physical effective energy functions: free energy analysis of lambda repressor-DNA complexes.

    Directory of Open Access Journals (Sweden)

    Caselle Michele

    2007-09-01

    Full Text Available Abstract Background Specific binding of proteins to DNA is one of the most common ways gene expression is controlled. Although general rules for the DNA-protein recognition can be derived, the ambiguous and complex nature of this mechanism precludes a simple recognition code, therefore the prediction of DNA target sequences is not straightforward. DNA-protein interactions can be studied using computational methods which can complement the current experimental methods and offer some advantages. In the present work we use physical effective potentials to evaluate the DNA-protein binding affinities for the λ repressor-DNA complex for which structural and thermodynamic experimental data are available. Results The binding free energy of two molecules can be expressed as the sum of an intermolecular energy (evaluated using a molecular mechanics forcefield, a solvation free energy term and an entropic term. Different solvation models are used including distance dependent dielectric constants, solvent accessible surface tension models and the Generalized Born model. The effect of conformational sampling by Molecular Dynamics simulations on the computed binding energy is assessed; results show that this effect is in general negative and the reproducibility of the experimental values decreases with the increase of simulation time considered. The free energy of binding for non-specific complexes, estimated using the best energetic model, agrees with earlier theoretical suggestions. As a results of these analyses, we propose a protocol for the prediction of DNA-binding target sequences. The possibility of searching regulatory elements within the bacteriophage λ genome using this protocol is explored. Our analysis shows good prediction capabilities, even in absence of any thermodynamic data and information on the naturally recognized sequence. Conclusion This study supports the conclusion that physics-based methods can offer a completely complementary

  2. Power Shift

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ "We are entering a new era of world history: the end of Western domination and the arrival of the Asian century. The question is: will Washington wake up to this reality?" This is the central premise of Kishore Mahbubani's provocative new book The New Asian Hemisphere: The Irresistible Shift of Global Power to the East.

  3. The solution structure of Ln (DOTP) 5- complexxes. A comparison of lanthanide-induced paramagnetic shifts with the MMX energy-minimized structure

    Science.gov (United States)

    Geraldes, Carlos F. G. C.; Sherry, A. Dean; Kiefer, Garry E.

    Complexes between the trivalent lanthanide ions and the macrocyclic chelate 1,4,7,10-tetraazacyclododecane- N,N',N″,N‴-tetra(methylene phosphonate) (DOTP) have been examined by high-resolution NMR spectroscopy. The proton spectra of the diamagnetic La(DOTP) 5- and Lu(DOTP) 5- complexes provide evidence for very rigid chelate structures with the ethylenediamine-containing chelate rings essentially locked into a single conformation at room temperature. The activation energy for ethylenediamine chelate ring interconversions in these complexes is approximately 100 kJ mol -1, considerably higher than that reported previously for the corresponding Ln(DOTA) - complexes (DOTA is the tetraacetate analog of DOTP). Lanthanide-induced shifts are reported for all 1H, 13C, and 31P nuclei in 11 Ln(DOTP) 5- complexes. The proton spectra of these complexes display unusually large lanthanide-induced shifts, one showing a spectrum in which the 1H resonances span 900 ppm. The contact and pseudocontact contributions to these shifts were separated using Reilley's temperature-independent method and the resulting pseudocontact lanthanide-induced NMR shifts were in excellent agreement with those calculated for a structure derived using MMX molecular modeling methods. The pseudocontact shifts provide evidence for Ln (DOTP) 5- chelates which have virtually identical structures along the lanthanide series, with the possible exception of Tm(DOTP) 5-.

  4. Measurement of the binding energy of ultracold $^{87}$Rb$^{133}$Cs molecules using an offset-free optical frequency comb

    CERN Document Server

    Molony, Peter K; Gregory, Philip D; Kliese, Russell; Puppe, Thomas; Sueur, C Ruth Le; Aldegunde, Jesus; Hutson, Jeremy M; Cornish, Simon L

    2016-01-01

    We report the binding energy of $^{87}$Rb$^{133}$Cs molecules in their rovibrational ground state measured using an offset-free optical frequency comb based on difference frequency generation technology. We create molecules in the absolute ground state using stimulated Raman adiabatic passage (STIRAP) with a transfer efficiency of 88\\%. By measuring the absolute frequencies of our STIRAP lasers, we find the energy-level difference from an initial weakly-bound Feshbach state to the rovibrational ground state with a resolution of 5 kHz over an energy-level difference of more than 114 THz; this lets us discern the hyperfine splitting of the ground state. Combined with theoretical models of the Feshbach state binding energies and ground-state hyperfine structure, we determine a zero-field binding energy of $h\\times114\\,268\\,135\\,237(5)(50)$ kHz. To our knowledge, this is the most accurate determination to date of the dissociation energy of a molecule.

  5. Development of homogeneous binding assays based on fluorescence resonance energy transfer between quantum dots and Alexa Fluor fluorophores.

    Science.gov (United States)

    Nikiforov, Theo T; Beechem, Joseph M

    2006-10-01

    We studied the fluorescence resonance energy transfer (FRET) between quantum dots emitting at 565, 605, and 655 nm as energy donors and Alexa Fluor fluorophores with absorbance maxima at 594, 633, 647, and 680 nm as energy acceptors. As a first step, we prepared covalent conjugates between all three types of quantum dots and each of the Alexa Fluor fluorophores that could act as an energy acceptor. All of these conjugates displayed efficient resonance energy transfer. Then we prepared covalent conjugates of these quantum dots with biotin, fluorescein, and cortisol and established that the binding of these conjugates to suitable Alexa Fluor-labeled antibodies and streptavidin (in the case of biotin) can be efficiently detected by measuring the resonance energy transfer in homogeneous solutions. Finally, based on these observations, competitive binding assays for these three small analytes were developed. The performance of these assays as a function of the degree of labeling of the quantum dots was evaluated. It was found that decreasing the degree of loading of the quantum dots leads to decreases of the limits of detection. The results show the great potential of this FRET system for the development of new homogeneous binding assays.

  6. Why baryons are Yang-Mills magnetic monopoles, validated by nuclear binding energies and proton and neutron masses

    Science.gov (United States)

    Yablon, Jay R.

    2013-10-01

    Evidence is summarized from four recent papers that baryons including protons and neutrons are magnetic monopoles of non-commuting Yang-Mills gauge theories: 1) Protons and neutrons are ``resonant cavities'' with binding energies determined strictly by the masses of the quarks they contain. This is proven true at parts-per million accuracy for each of the 2H, 3H,3He, 4He binding energies and the neutron minus proton mass difference. 2) Respectively, each free proton and neutron contains 7.64 MeV and 9.81 MeV of mass/energy used to confine its quarks. When these nucleons bind, some, never all, of this energy is released and the mass deficit goes into binding. The balance continues to confine quarks. 56Fe releases 99.8429% of this energy for binding, more than any other nuclide. 3) Once we consider the Fermi vev one also finds an entirely theoretical explanation of proton and neutron masses, which also connects within experimental errors to the CKM quark mixing angles. 4) A related GUT explains fermion generation replication based on generator loss during symmetry breaking, and answers Rabi's question ``who ordered this?'' 5) Nuclear physics is governed by combining Maxwell's two classical equations into one equation using non-commuting gauge fields in view of Dirac theory and Fermi-Dirac-Pauli Exclusion. 6) Atoms themselves are core magnetic charges (nucleons) paired with orbital electric charges (electrons and elusive neutrinos), with the periodic table itself revealing an electric/magnetic symmetry of Maxwell's equations often pondered but heretofore unrecognized for a century and a half.

  7. Binding free energies for nicotine analogs inhibiting cytochrome P450 2A6 by a combined use of molecular dynamics simulations and QM/MM-PBSA calculations.

    Science.gov (United States)

    Lu, Haiting; Huang, Xiaoqin; AbdulHameed, Mohamed Diwan M; Zhan, Chang-Guo

    2014-04-01

    Molecular dynamics (MD) simulations and hybrid quantum mechanical/molecular mechanical (QM/MM) calculations have been performed to explore the dynamic behaviors of cytochrome P450 2A6 (CYP2A6) binding with nicotine analogs (that are typical inhibitors) and to calculate their binding free energies in combination with Poisson-Boltzmann surface area (PBSA) calculations. The combined MD simulations and QM/MM-PBSA calculations reveal that the most important structural parameters affecting the CYP2A6-inhibitor binding affinity are two crucial internuclear distances, that is, the distance between the heme iron atom of CYP2A6 and the coordinating atom of the inhibitor, and the hydrogen-bonding distance between the N297 side chain of CYP2A6 and the pyridine nitrogen of the inhibitor. The combined MD simulations and QM/MM-PBSA calculations have led to dynamic CYP2A6-inhibitor binding structures that are consistent with the observed dynamic behaviors and structural features of CYP2A6-inhibitor binding, and led to the binding free energies that are in good agreement with the experimentally-derived binding free energies. The agreement between the calculated binding free energies and the experimentally-derived binding free energies suggests that the combined MD and QM/MM-PBSA approach may be used as a valuable tool to accurately predict the CYP2A6-inhibitor binding affinities in future computational design of new, potent and selective CYP2A6 inhibitors. PMID:24631364

  8. Electron momentum distributions and binding energies for the valence orbitals of hydrogen bromide and hydrogen iodide

    International Nuclear Information System (INIS)

    The electron binding energy spectra and momentum distributions have been obtained for the valence orbitals of HBr and HI using noncoplanar symmetric electron coincidence spectroscopy at 1200eV. The weakly bonding inner valence ns orbitals, which have not been previously observed, have their spectroscopic (pole) strength severely split among a number of ion states. For HBr the strength of the main inner valence (ns) transition is 0.42 0.03 whereas for HI it is 0.37 0.04, in close agreement with that observed for the valence s orbitals of the corresponding isoelectronic inert gas atoms. The spectroscopic strength for the two outermost orbitals is found to be close to unity, in agreement with many body Green's function calculations. The measured momentum distributions are compared with several spherically averaged MO momentum distributions, as well as (for HBr) with a Green's function calculation of the generalized overlap amplitude (GOA). The GOA momentum distributions are in excellent agreement with the HBr data, both in shape and relative magnitude. Not all of the MO momentum distributions are in reasonable agreement with the data. Comparison is also made with the calculated momentum distributions for Kr, Br, Xe and I

  9. Isotopic dependence of the nuclear charge radii and binding energies in the relativistic Hartree-Fock formalism

    Energy Technology Data Exchange (ETDEWEB)

    Niembro, R., E-mail: niembror@unican.es; Marcos, S.; Lopez-Quelle, M. [Universidad de Cantabria (Spain); Savushkin, L. N. [St. Petersburg University for Telecommunications (Russian Federation)

    2012-03-15

    Relativistic nonlinear models based on the Hartree and Hartree-Fock approximations, including the {sigma}, {omega}, {pi}, and {rho} mesons, are worked out to explore the behavior of the nuclear charge radii and the binding energies of several isotopic chains. We find a correlation between the magnitude of the anomalous kink effect (KE) in the Pb isotopic family and the compressibility modulus (K) of nuclear matter. The KE appears to be sensitive, in particular, to the mechanisms which control the K value. The influence of the symmetry energy on the Ca isotopic chain is also studied. The behavior of the charge radii of single-particle states for some special cases and its repercussion on the nuclear charge radius is analyzed. The effect of pairing correlations on the models improves considerably the quality of the results in both binding energy and KE.

  10. L X-ray energy shifts and intensity ratios in tantalum with C and N ions – multiple vacancies in M, N and O shells

    Indian Academy of Sciences (India)

    Y Ramakrishna; K Ramachandra Rao; G J Naga Raju; K Bhaskara Rao; V Seshagiri Rao; P Venkateswarlu; S Bhuloka Reddy

    2002-10-01

    The energy shifts and intensity ratios of different L X-ray components in tantalum element due to 10 MeV carbon and 12 MeV nitrogen ions are estimated. From the observed energy shifts, the possible number of simultaneous vacancies in M shell are estimated. A comparison of L/L 2,15, L 1/L 1 and L 2,3/L 4,4 with the ratios due to Scofield theoretical transition rates indicate that the number of multiple vacancies in N shell are higher than the vacancies in M and O shell. Employing Larkin’s statistical scaling procedure, the number of possible multiple vacancies in N and O shells are estimated quantitatively.

  11. A thermalization energy analysis of the threshold voltage shift in amorphous indium gallium zinc oxide thin film transistors under positive gate bias stress

    Science.gov (United States)

    Niang, K. M.; Barquinha, P. M. C.; Martins, R. F. P.; Cobb, B.; Powell, M. J.; Flewitt, A. J.

    2016-02-01

    Thin film transistors (TFTs) employing an amorphous indium gallium zinc oxide (a-IGZO) channel layer exhibit a positive shift in the threshold voltage under the application of positive gate bias stress (PBS). The time and temperature dependence of the threshold voltage shift was measured and analysed using the thermalization energy concept. The peak energy barrier to defect conversion is extracted to be 0.75 eV and the attempt-to-escape frequency is extracted to be 107 s-1. These values are in remarkable agreement with measurements in a-IGZO TFTs under negative gate bias illumination stress (NBIS) reported recently (Flewitt and Powell, J. Appl. Phys. 115, 134501 (2014)). This suggests that the same physical process is responsible for both PBS and NBIS, and supports the oxygen vacancy defect migration model that the authors have previously proposed.

  12. Subsite binding energies of an exo-polygalacturonase using isothermal titration calorimetry

    Science.gov (United States)

    Thermodynamic parameters for binding of a series of galacturonic acid oligomers to an exo-polygalacturonase, RPG16 from Rhizopus oryzae, were determined by isothermal titration calorimetry. Binding of oligomers varying in chain length from two to five galacturonic acid residues is an exothermic proc...

  13. Influence of position dependent effective mass on donor binding energy in square and V-shaped quantum wells in the presence of a magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Panahi, H., E-mail: t-panahi@guilan.ac.ir [Department of Physics, University of Guilan, 41335-1914 Rasht (Iran, Islamic Republic of); Golshahi, S. [Department of Physics, Rasht Branch, Islamic Azad University, Rasht (Iran, Islamic Republic of); Doostdar, M. [Department of Physics, University of Guilan, 41335-1914 Rasht (Iran, Islamic Republic of)

    2013-06-01

    In this paper we have calculated variationally the ground state binding energy of a hydrogenic donor impurity in square quantum well and V-shaped quantum well as a function of the well width in the presence of magnetic fields with both constant and position dependent effective mass. The wave function of electrons confined to donor impurity within the quantum well is considered as the two dimensional and three dimensional trial wave functions. It has been found that by increasing the well width, the binding energy decreases smoothly to bulk values while its steepness is sharper in square quantum well in comparison with V-shaped quantum well. Increasing the magnetic field leads to the enhancement of binding energy. At higher magnetic fields, by increasing the well width, binding energy tends to a constant value. The effect of position dependent effective mass on the enhancement of binding energy is more evident in comparison with constant effective mass one.

  14. Influence of position dependent effective mass on donor binding energy in square and V-shaped quantum wells in the presence of a magnetic field

    International Nuclear Information System (INIS)

    In this paper we have calculated variationally the ground state binding energy of a hydrogenic donor impurity in square quantum well and V-shaped quantum well as a function of the well width in the presence of magnetic fields with both constant and position dependent effective mass. The wave function of electrons confined to donor impurity within the quantum well is considered as the two dimensional and three dimensional trial wave functions. It has been found that by increasing the well width, the binding energy decreases smoothly to bulk values while its steepness is sharper in square quantum well in comparison with V-shaped quantum well. Increasing the magnetic field leads to the enhancement of binding energy. At higher magnetic fields, by increasing the well width, binding energy tends to a constant value. The effect of position dependent effective mass on the enhancement of binding energy is more evident in comparison with constant effective mass one

  15. Steric and allosteric effects of fatty acids on the binding of warfarin to human serum albumin revealed by molecular dynamics and free energy calculations.

    Science.gov (United States)

    Fujiwara, Shin-Ichi; Amisaki, Takashi

    2011-01-01

    Human serum albumin (HSA) binds with drugs and fatty acids (FAs). This study was initiated to elucidate the relationship between the warfarin binding affinity of HSA and the positions of bound FA molecules. Molecular dynamics simulations of 11 HSA-warfarin-myristate complexes were performed. HSA-warfarin binding free energy was then calculated for each of the complexes by the molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA) method. The results indicated that the magnitude of the binding free energy was smaller in HSA-warfarin complexes that had 4 or more myristate molecules than in complexes with no myristate molecules. The unfavorable effect on the HSA-warfarin binding affinity was caused sterically by the binding of a myristate molecule to the FA binding site closest to the warfarin binding site. On the other hand, the magnitude of HSA-warfarin binding free energy was largest when 3 myristate molecules were bound to the high-affinity sites. The strongest HSA-warfarin binding was attributable to favorable entropic contribution related to larger atomic fluctuations of the amino acid residues at the warfarin binding site. In the binding of 2 myristate molecules to the sites with the highest and second-highest affinities, allosteric modulation that enhanced electrostatic interactions between warfarin and some of the amino acid residues around the warfarin binding site was observed. This study clarified the structural and energetic properties of steric/allosteric effects of FAs on the HSA-warfarin binding affinity and illustrated the approach to analyze protein-ligand interactions in situations such that multiple ligands bind to the other sites of the protein. PMID:21720037

  16. Shedding Light on the EOS-Gravity Degeneracy and Constraining the Nuclear Symmetry Energy from the Gravitational Binding Energy of Neutron Stars

    OpenAIRE

    He Xiao-Tao; Fattoyev F. J.; Li Bao-An; Newton W. G.

    2016-01-01

    A thorough understanding of properties of neutron stars requires both a reliable knowledge of the equation of state (EOS) of super-dense nuclear matter and the strong-field gravity theories simultaneously. To provide information that may help break this EOS-gravity degeneracy, we investigate effects of nuclear symmetry energy on the gravitational binding energy of neutron stars within GR and the scalar-tensor subset of alternative gravity models. We focus on effects of the slope $L$ of nuclea...

  17. Shifting densities

    OpenAIRE

    Mille, Matthieu

    2000-01-01

    In this paper, the author adopt a time-geography approach to examine the temporal variation of urban density by analysing spatial load changes at different times of the day at the communal and community level. The evolution of means of transport coupled with the abandon of the notion of direct proximity to the urban dwelling place provide the basis for this new approach to the study of urban densities. The shift towards spatial specialisation within cities has lead to radical changes in the f...

  18. Binding and Adsorption Energies of Heavy Metal Ions with Hapli-Udic Argosol and Ferri-Udic Argosol Particles

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Gibbs free binding energy and adsorption energy between cations and charged soil particles were used to evaluate the interactions between ions and soil particles. The distribution of Gibbs free adsorption energies could not be determined experimentally before the development of Wien effect measurements in dilute soil suspensions. In the current study, energy relationships between heavy metal ions and particles of Hapli-Udic Argosol (Alfisol) and Ferri-Udic Argosol were inferred from Wien effect measurements in dilute suspensions of homoionic soil particles (< 2 μm) of the two soils, which were saturated with ions of five heavy metals, in deionized water. The mean Gibbs free binding energies of the heavy metal ions with Hapli-Udic Argosol and Ferri-Udic Argosol particles diminished in the order of Pb2+>Cd2+>Cu2+> Zn2+ >Cr3+, where the range of binding energies for Hapli-Udic Argosol (7.25-9.32 kJ mol-1) was similar to that for Ferri-Udic Argosol (7.43-9.35 kJ mol-1). The electrical field-dependent mean Gibbs free adsorption energies of these heavy metal ions for Hapli-Udic Argosol and for Ferri-Udic Argosol descended in the order: Cu2+≥ Cd2+≥ Pb2+ > Zn2+>Cr3+,and Cd2+ >Cu2+>Pb2+>Zn2+>Cr3+, respectively. The mean Gibbs free adsorption energies of Cu2+, Zn2+, Cd2+,Pb2+, and Cr3+ at a field strength of 200 kV cm-1, for example, were in the range of 0.8-3.2 kJ mol-1 for the two soils.

  19. Design principles of shift current photovoltaics

    Science.gov (United States)

    Cook, Ashley; Fregoso, Benjamin; de Juan, Fernando; Moore, Joel

    While the basic principles and limitations of conventional solar cells are well understood, relatively little attention has gone toward evaluating and maximizing the potential efficiency of photovoltaic devices based on shift currents. In this work, a sum rule approach is introduced and used to outline design principles for optimizing shift currents for photon energies near the band gap, which depend on wavefunctions via Berry connections as well as standard band structure. Using these we identify two new classes of shift current photovoltaics, ferroelectric polymer films and orthorhombic monochalcogenides, both of which exhibit peak photoresponsivities larger than predictions for previously-known photovoltaics of this type. Using physically-motivated tight-binding models, the full frequency dependent response of these materials is obtained. Exploring the phase space of these models, we find photoresponsivities that can exceed 100 mA/W. These results show that considering the microscopic origin of shift current via effective models allows one to improve the possible efficiency of devices using this mechanism and better grasp their potential to compete with conventional solar cells. This work was completed with the support of an NSERC Michael Smith Foreign Study Supplement.

  20. Influence of geometrical factor on binding energy of Cooper pairs in YBa2Cu3O7-δ compound

    Science.gov (United States)

    Ibrahim, Saeed O.; Mustafa, Bassam M.

    2016-03-01

    In this research the influence of geometrical factors on binding energy between Cooper pairs are investigated for the high temperature superconducting (YBa2Cu3O7-δ) compound. This is done by using a model considering that the formation of Cooper pairs happens during tunneling mechanism of holes between the two CuO2 layers in the YBCO crystal which are considered as forming adjacent ridged potential wells. According to this model binding energy is: Eb i n=4/√{2 }m3/2 π2ħ3p ×∫U-0(U -0-E) exp [-2/(d -Rc) ħ √{2 m (U -E ) } ] √{E } d E 0 is a work function, ħ is the Plank's constant, m is the electron mass, and U is the height of the potential barrier, E is the energy, Rc is the electron cloud radius in tunneling direction and d is the distance between the two CuO2 planes. In the above model two effects of geometrical factors were ignored, considering that ridges in the two CuO2 layers as having rectangular shape, but in reality the ridges in the potential well are of triangular shape. Also the model considers the distance between layers as constant but really the distant d is variable due to the triangular geometry. In this work we consider both effects that affect the density of state in the potential well and the tunneling probability. Then binding energy between the Cooper pairs, is calculated.

  1. Molecular Dynamics Simulation of Tryptophan Hydroxylase-1: Binding Modes and Free Energy Analysis to Phenylalanine Derivative Inhibitors

    Directory of Open Access Journals (Sweden)

    Liang Ouyang

    2013-05-01

    Full Text Available Serotonin is a neurotransmitter that modulates many central and peripheral functions. Tryptophan hydroxylase-1 (TPH1 is a key enzyme of serotonin synthesis. In the current study, the interaction mechanism of phenylalanine derivative TPH1 inhibitors was investigated using molecular dynamics (MD simulations, free energy calculations, free energy decomposition analysis and computational alanine scanning. The predicted binding free energies of these complexes are consistent with the experimental data. The analysis of the individual energy terms indicates that although the van der Waals and electrostatics interaction contributions are important in distinguishing the binding affinities of these inhibitors, the electrostatic contribution plays a more crucial role in that. Moreover, it is observed that different configurations of the naphthalene substituent could form different binding patterns with protein, yet lead to similar inhibitory potency. The combination of different molecular modeling techniques is an efficient way to interpret the interaction mechanism of inhibitors and our work could provide valuable information for the TPH1 inhibitor design in the future.

  2. Quantum electrodynamics based on self-energy, without second quantization: The Lamb shift and long-range Casimir-Polder van der Waals forces near boundaries

    International Nuclear Information System (INIS)

    Using a previously formulated theory of quantum electrodynamics based on self-energy, we give a general method for computing the Lamb shift and related Casimir-Polder energies for a quantum system in the vicinity of perfectly conducting boundaries. Our results are exact and easily extendable to a full covariant relativistic form. As a particular example we apply the method to an atom near an infinite conducting plane, and we recover the standard QED results (which are known only in the dipole approximation) in a simple and straightforward manner. This is accomplished in the context of the new theory which is not second quantized and contains no vacuum fluctuations. (author)

  3. The effects of the electric and intense laser field on the binding energies of donor impurity states (1s and 2p±) and optical absorption between the related states in an asymmetric parabolic quantum well

    Science.gov (United States)

    Kasapoglu, E.; Sakiroglu, S.; Sökmen, I.; Restrepo, R. L.; Mora-Ramos, M. E.; Duque, C. A.

    2016-10-01

    We have calculated the effects of electric and intense laser fields on the binding energies of the ground and some excited states of conduction electrons coupled to shallow donor impurities as well as the total optical absorption coefficient for transitions between 1s and 2p± electron-impurity states in a asymmetric parabolic GaAs/Ga1-x AlxAs quantum well. The binding energies were obtained using the effective-mass approximation within a variational scheme. Total absorption coefficient (linear and nonlinear absorption coefficient) for the transitions between any two impurity states were calculated from first- and third-order dielectric susceptibilities derived within a perturbation expansion for the density matrix formalism. Our results show that the effects of the electric field, intense laser field, and the impurity location on the binding energy of 1s-impurity state are more pronounced compared with other impurity states. If the well center is changed to be Lc0), the effective well width decreases (increases), and thus we can obtain the red or blue shift in the resonant peak position of the absorption coefficient by changing the intensities of the electric and non-resonant intense laser field as well as dimensions of the well and impurity positions.

  4. Surface shift of the occupied and unoccupied 4f levels of the rare-earth metals

    DEFF Research Database (Denmark)

    Aldén, Magnus; Johansson, Börje; Skriver, Hans Lomholt

    1995-01-01

    The surface energy shifts of the occupied and unoccupied 4f levels for the lanthanide metals have been calculated from first principles by means of a Green’s-function technique within the tight-binding linear muffin-tin orbitals method. We use the concept of complete screening to identify the occ...

  5. Magnetic field-dependent of binding energy in GaN/InGaN/GaN spherical QDQW nanoparticles

    Science.gov (United States)

    El Ghazi, Haddou; Jorio, Anouar; Zorkani, Izeddine

    2013-10-01

    Simultaneous study of magnetic field and impurity's position effects on the ground-state shallow-donor binding energy in GaN│InGaN│GaN (core│well│shell) spherical quantum dot-quantum well (SQDQW) as a function of the ratio of the inner and the outer radius is reported. The calculations are investigated within the framework of the effective-mass approximation and an infinite deep potential describing the quantum confinement effect. A Ritz variational approach is used taking into account of the electron-impurity correlation and the magnetic field effect in the trial wave-function. It appears that the binding energy depends strongly on the external magnetic field, the impurity's position and the structure radius. It has been found that: (i) the magnetic field effect is more marked in large layer than in thin layer and (ii) it is more pronounced in the spherical layer center than in its extremities.

  6. Total energy calculation of perovskite, BaTiO3, by self-consistent tight binding method

    Indian Academy of Sciences (India)

    B T Cong; P N A Huy; P K Schelling; J W Halley

    2003-01-01

    We present results of numerical computation on some characteristics of BaTiO3 such as total energy, lattice constant, density of states, band structure etc using self-consistent tight binding method. Besides strong Ti–O bond between 3 on titanium and 2 orbital on oxygen states, we also include weak hybridization between the Ba 6 and O 2 states. The results are compared with those of other more sophisticated methods.

  7. Binding Energy of Positively and Negatively Charged Excitons in GaAs/AlxGal-xAs Quantum Wells

    Institute of Scientific and Technical Information of China (English)

    刘建军; 张淑芳; 杨国琛; 李树深

    2002-01-01

    Using a simple two-parameter wavefunction, we calculate variationally the binding energy of positively and negatively charged excitons in GaAs/AlxGa1-xAs quantum wells for well widths from 10 to 300A. We consider the effect of effective mass, dielectric constant mismatch in the two materials, and the whole correlation among the particles. The results are discussed and compared in detail with previous experimental and theoretical results,which show fair agreement with them.

  8. A New Model for Calculating the Binding Energy of Lithium Nucleus under the Generalized Yukawa Potential and Hellmann Potential

    OpenAIRE

    Ghazvini, M; Salehi, N; Rajabi, A. A.

    2014-01-01

    In this paper, the Schr\\"odinger equation for 6-body system is studied. We solved this equation for lithium nucleus by using supersymmetry method with the specific potentials. These potentials are Yukawa potential, the generalized Yukawa potential and Hellmann potential. The results of our model for all calculations show that the ground state binding energy of Lithium nucleus with these potentials are very close to the ones obtained in experiments.

  9. The effect of Fermi momentum cutoff on the binding energy of closed-shell nuclei in the LOCV framework

    International Nuclear Information System (INIS)

    The ground-state binding energies of the light symmetric closed-shell nuclei, i.e., 4He, 12C, 16O and 40Ca, and the heavy asymmetric ones, i.e., 48Ca, 90Zr and 120Sn, are calculated in the harmonic oscillator (HOS) basis, by imposing the relative Fermi momentum cutoff of two point-like interacting nucleons on the density-dependent average effective interactions (DDAEI). The DDAEI are generated through the lowest order constrained variational (LOCV) method calculations for the asymmetric nuclear matter with the operator and the channel-dependent-type bare nucleon-nucleon potentials, such as the Argonne Av18jmax=2 and the Reid soft core, Reid68, interactions. In the framework of the harmonic oscillator shell model, the cutoff is imposed by defining the maximum value of the relative quantum numbers (RQNmax) in two ways: (1) the RQNmax of the last shell and (2) the RQNmax of each shell, in the ground state of the nucleus. It is shown that present results on the binding energies and the root-mean-square radius are closer to the corresponding experimental data than our previous works with the same DDAEI potentials, but without the cutoff constraint. However, for the light symmetric nuclei, the second scheme gives less binding energy and larger root-mean-square radius compared to the first one, while the situation is reversed for the heavier nuclei.

  10. Configuration space method for calculating binding energies of exciton complexes in quasi-1D/2D semiconductors

    Science.gov (United States)

    Bondarev, Igor

    A configuration space method, pioneered by Landau and Herring in studies of molecular binding and magnetism, is developed to obtain universal asymptotic relations for lowest energy exciton complexes (trion, biexciton) in confined semiconductor nanostructures such as nanowires and nanotubes, as well as coupled quantum wells. Trions are shown to be more stable (have greater binding energy) than biexcitons in strongly confined quasi-1D structures with small reduced electron-hole masses. Biexcitons are more stable in less confined quasi-1D structures with large reduced electron-hole masses. The theory predicts a crossover behavior, whereby trions become less stable than biexcitons as the transverse size of the quasi-1D nanostructure increases, which might be observed on semiconducting carbon nanotubes of increasing diameters. This method is also efficient in calculating binding energies for trion-type electron-hole complexes formed by indirect excitons in double coupled quantum wells, quasi-2D nanostructures that show new interesting electroabsorption/refraction phenomena. Supported by DOE-DE-SC0007117.

  11. Binding Free Energy Calculations for Lead Optimization: Assessment of Their Accuracy in an Industrial Drug Design Context.

    Science.gov (United States)

    Homeyer, Nadine; Stoll, Friederike; Hillisch, Alexander; Gohlke, Holger

    2014-08-12

    Correctly ranking compounds according to their computed relative binding affinities will be of great value for decision making in the lead optimization phase of industrial drug discovery. However, the performance of existing computationally demanding binding free energy calculation methods in this context is largely unknown. We analyzed the performance of the molecular mechanics continuum solvent, the linear interaction energy (LIE), and the thermodynamic integration (TI) approach for three sets of compounds from industrial lead optimization projects. The data sets pose challenges typical for this early stage of drug discovery. None of the methods was sufficiently predictive when applied out of the box without considering these challenges. Detailed investigations of failures revealed critical points that are essential for good binding free energy predictions. When data set-specific features were considered accordingly, predictions valuable for lead optimization could be obtained for all approaches but LIE. Our findings lead to clear recommendations for when to use which of the above approaches. Our findings also stress the important role of expert knowledge in this process, not least for estimating the accuracy of prediction results by TI, using indicators such as the size and chemical structure of exchanged groups and the statistical error in the predictions. Such knowledge will be invaluable when it comes to the question which of the TI results can be trusted for decision making.

  12. Shedding Light on the EOS-Gravity Degeneracy and Constraining the Nuclear Symmetry Energy from the Gravitational Binding Energy of Neutron Stars

    CERN Document Server

    He, Xiao-Tao; Li, Bao-An; Newton, W G

    2015-01-01

    A thorough understanding of properties of neutron stars requires both a reliable knowledge of the equation of state (EOS) of super-dense nuclear matter and the strong-field gravity theories simultaneously. To provide information that may help break this EOS-gravity degeneracy, we investigate effects of nuclear symmetry energy on the gravitational binding energy of neutron stars within GR and the scalar-tensor subset of alternative gravity models. We focus on effects of the slope $L$ of nuclear symmetry energy at saturation density and the high-density behavior of nuclear symmetry energy. We find that the variation of either the density slope $L$ or the high-density behavior of nuclear symmetry energy leads to large changes in the binding energy of neutron stars. The difference in predictions using the GR and the scalar-tensor theory appears only for massive neutron stars, and even then is significantly smaller than the difference resulting from variations in the symmetry energy.

  13. Toward an Accurate and Inexpensive Estimation of CCSD(T)/CBS Binding Energies of Large Water Clusters.

    Science.gov (United States)

    Sahu, Nityananda; Singh, Gurmeet; Nandi, Apurba; Gadre, Shridhar R

    2016-07-21

    Owing to the steep scaling behavior, highly accurate CCSD(T) calculations, the contemporary gold standard of quantum chemistry, are prohibitively difficult for moderate- and large-sized water clusters even with the high-end hardware. The molecular tailoring approach (MTA), a fragmentation-based technique is found to be useful for enabling such high-level ab initio calculations. The present work reports the CCSD(T) level binding energies of many low-lying isomers of large (H2O)n (n = 16, 17, and 25) clusters employing aug-cc-pVDZ and aug-cc-pVTZ basis sets within the MTA framework. Accurate estimation of the CCSD(T) level binding energies [within 0.3 kcal/mol of the respective full calculation (FC) results] is achieved after effecting the grafting procedure, a protocol for minimizing the errors in the MTA-derived energies arising due to the approximate nature of MTA. The CCSD(T) level grafting procedure presented here hinges upon the well-known fact that the MP2 method, which scales as O(N(5)), can be a suitable starting point for approximating to the highly accurate CCSD(T) [that scale as O(N(7))] energies. On account of the requirement of only an MP2-level FC on the entire cluster, the current methodology ultimately leads to a cost-effective solution for the CCSD(T) level accurate binding energies of large-sized water clusters even at the complete basis set limit utilizing off-the-shelf hardware. PMID:27351269

  14. Anomalous center of mass shift: gravitational dipole moment.

    Science.gov (United States)

    Jeong, Eue Jin

    1997-02-01

    The anomalous, energy dependent shift of the center of mass of an idealized, perfectly rigid, uniformly rotating hemispherical shell which is caused by the relativistic mass increase effect is investigated in detail. It is shown that a classical object on impact which has the harmonic binding force between the adjacent constituent particles has the similar effect of the energy dependent, anomalous shift of the center of mass. From these observations, the general mode of the linear acceleration is suggested to be caused by the anomalous center of mass shift whether it's due to classical or relativistic origin. The effect of the energy dependent center of mass shift perpendicular to the plane of rotation of a rotating hemisphere appears as the non zero gravitational dipole moment in general relativity. Controlled experiment for the measurement of the gravitational dipole field and its possible links to the cylindrical type line formation of a worm hole in the extreme case are suggested. The jets from the black hole accretion disc and the observed anomalous red shift from far away galaxies are considered to be the consequences of the two different aspects of the dipole gravity.

  15. Predicting paramagnetic 1H NMR chemical shifts and state-energy separations in spin-crossover host-guest systems.

    Science.gov (United States)

    Isley, William C; Zarra, Salvatore; Carlson, Rebecca K; Bilbeisi, Rana A; Ronson, Tanya K; Nitschke, Jonathan R; Gagliardi, Laura; Cramer, Christopher J

    2014-06-14

    The behaviour of metal-organic cages upon guest encapsulation can be difficult to elucidate in solution. Paramagnetic metal centres introduce additional dispersion of signals that is useful for characterisation of host-guest complexes in solution using nuclear magnetic resonance (NMR). However, paramagnetic centres also complicate spectral assignment due to line broadening, signal integration error, and large changes in chemical shifts, which can be difficult to assign even for known compounds. Quantum chemical predictions can provide information that greatly facilitates the assignment of NMR signals and identification of species present. Here we explore how the prediction of paramagnetic NMR spectra may be used to gain insight into the spin crossover (SCO) properties of iron(II)-based metal organic coordination cages, specifically examining how the structure of the local metal coordination environment affects SCO. To represent the tetrahedral metal-organic cage, a model system is generated by considering an isolated metal-ion vertex: fac-ML3(2+) (M = Fe(II), Co(II); L = N-phenyl-2-pyridinaldimine). The sensitivity of the (1)H paramagnetic chemical shifts to local coordination environments is assessed and utilised to shed light on spin crossover behaviour in iron complexes. Our data indicate that expansion of the metal coordination sphere must precede any thermal SCO. An attempt to correlate experimental enthalpies of SCO with static properties of bound guests shows that no simple relationship exists, and that effects are likely due to nuanced dynamic response to encapsulation. PMID:24752730

  16. Performance of the TPSS Functional on Predicting Core Level Binding Energies of Main Group Elements Containing Molecules: A Good Choice for Molecules Adsorbed on Metal Surfaces.

    Science.gov (United States)

    Pueyo Bellafont, Noèlia; Viñes, Francesc; Illas, Francesc

    2016-01-12

    Here we explored the performance of Hartree-Fock (HF), Perdew-Burke-Ernzerhof (PBE), and Tao-Perdew-Staroverov-Scuseria (TPSS) functionals in predicting core level 1s binding energies (BEs) and BE shifts (ΔBEs) for a large set of 68 molecules containing a wide variety of functional groups for main group elements B → F and considering up to 185 core levels. A statistical analysis comparing with X-ray photoelectron spectroscopy (XPS) experiments shows that BEs estimations are very accurate, TPSS exhibiting the best performance. Considering ΔBEs, the three methods yield very similar and excellent results, with mean absolute deviations of ∼0.25 eV. When considering relativistic effects, BEs deviations drop approaching experimental values. So, the largest mean percentage deviation is of 0.25% only. Linear trends among experimental and estimated values have been found, gaining offsets with respect to ideality. By adding relativistic effects to offsets, HF and TPSS methods underestimate experimental values by solely 0.11 and 0.05 eV, respectively, well within XPS chemical precision. TPSS is posed as an excellent choice for the characterization, by XPS, of molecules on metal solid substrates, given its suitability in describing metal substrates bonds and atomic and/or molecular orbitals.

  17. Energy Spectrum of La3Lu2Ga3O12:Cr3+ and Its Pressure-Induced R-Line-Shift Reversal

    Science.gov (United States)

    Ma, Dong-Ping; Chen, Ju-Rong

    2005-12-01

    By means of both the theory for pressure-induced shifts (PS) of energy spectra and the theory for shifts of energy spectra due to electron-phonon interaction (EPI), the normal-pressure energy spectra of α and β centers of Cr3+ ions for LLGG:Cr3+ and the PS's of R1 lines and U band of these centers have been calculated at 10 K, respectively. The total calculated results are in very good agreement with the experimental data. For LLGG:Cr3+, the pressure-induced low-high crystal-field transition and the reversal of R1-line PS take place. The pressure-dependent variation of Rmixel (2E-4T2) [mixing-degree of |t22(3T1)e4T2 rangle and |t23 2Erangle base-wavefunctions in the wavefunction of R1 state without EPI] plays a key role for the reversal of R1-line PS. The behavior of the pure electronic PS of R1 line is quite different from that of the PS of R1 line due to EPI. It is the combined effect of them that gives rise to the total PS of R1 line. The comparison between R1-line PS's of GSGG:Cr3+ and LLGG:Cr3+ has been made. It is found that a peak of R1-line PS appears at Rmixel (2E-4T2) ≈ 0.08.

  18. Energy Spectrum of La3Lu2Ga3O12:Cr3+ and Its Pressure-Induced R-Line-Shift Reversal

    Institute of Scientific and Technical Information of China (English)

    MA Dong-Ping; CHEN Ju-Rong

    2005-01-01

    By means of both the theory for pressure-induced shifts (PS) of energy spectra and the theory for shifts of energy spectra due to electron-phonon interaction (EPI), the normal-pressure energy spectra of α andβ centers of Cr3+ions for LLGG:Cr3+ and the PS's of R1 lines and U band of these centers have been calculated at 10 K, respectively.The total calculated results are in very good agreement with the experimental data. For LLGG:Cr3+, the pressureinduced low-high crystal-field transition and the reversal of R1-line PS take place. The pressure-dependent variation of Relmix (2E- 4T2) [mixing-degree of |t22(3T1)e4T2) and |t322E) base-wavefunctions in the wavefunction of R1 state without EPI] plays a key role for the reversal of R1-line PS. The behavior of the pure electronic PS of R1 line is quite different from that of the PS of R1 line due to EPI. It is the combined effect of them that gives rise to the total PS of R1 line.The comparison between R1-line PS's of GSGG:Cr3+ and LLGG:Cr3+ has been made. It is found that a peak of R1-line PS appears at Relmix (2E - 4T2) ≈ 0.08.

  19. On the Inclusion of Energy-Shifting Demand Response in Production Cost Models: Methodology and a Case Study

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Hale, Elaine; Doebber, Ian;

    and communications, power system characteristics, regulatory environments, market structures, and business models. The work described in this report focuses on the enablement of such analysis from the production cost modeling perspective. In particular, we contribute a bottom-up methodology for modeling load...... storage technologies, and improving economic efficiency. In practice, DR from the commercial and residential sectors is largely an emerging, not a mature, resource, and its actual costs and benefits need to be studied to determine promising combinations of physical DR resource, enabling controls......-shifting DR in production cost models. The resulting model is sufficiently detailed to reflect the physical characteristics and constraints of the underlying flexible load, and includes the possibility of capturing diurnal and seasonal variations in the resource. Nonetheless, the model is of low complexity...

  20. Phase shift analysis of low energy $\\pi^{\\pm}p$ scattering data and a comparison with pionic hydrogen data

    CERN Document Server

    Gashi, A; Oades, G C; Rasche, G; Woolcock, W S

    2000-01-01

    Using newly calculated electromagnetic corrections, we have made a phase shift analysis of experimental data on pi+/- p elastic scattering up to 100 MeV, assuming the effective hadronic interaction to be isospin invariant. The output consists of parametrised s and p-wave hadronic phases for isospin 1/2 and 3/2. It is not possible to fit the charge exchange data satisfactorily. We give values for the s-wave scattering lengths and effective ranges and for the p-wave scattering volumes. The combinations 2a_1 + a_3 and a_1 - a_3 of s-wave scattering lengths extracted from pionic hydrogen data are compared with those obtained from our analysis.

  1. The Energy Level Shifts, Wave Functions and the Probability Current Distributions for the Bound Scalar and Spinor Particles Moving in a Uniform Magnetic Field

    CERN Document Server

    Rodionov, V N

    2011-01-01

    We discuss the equations for the bound one-active electron states based on the analytic solutions of the Schrodinger and Pauli equations for a uniform magnetic field and a single attractive $\\delta({\\bf r})$-potential. It is vary important that ground electron states in the magnetic field differ essentially from the analogous state of spin-0 particles, whose binding energy was intensively studied more than forty years ago. We show that binding energy equations for spin-1/2 particles can be obtained without using the language of boundary conditions in the $\\delta$-potential model developed in pioneering works. We use the obtained equations to calculate the energy level displacements analytically and demonstrate nonlinear dependencies on field intensity. We show that the magnetic field indeed plays a stabilizing role in considered systems in a case of the weak intensity, but the opposite occurs in the case of strong intensity. These properties may be important for real quantum mechanical fermionic systems in tw...

  2. Energy Spectra of the Tunable Laser Crystal Gd3Ga5O12:Cr3+ and Their Pressure-Induced Shifts

    Institute of Scientific and Technical Information of China (English)

    MA Dong-Ping

    2004-01-01

    By means of both the theory for pressure-induced shifts (PS) of energy spectra and the theory for shifts of energy spectra due to electron-phonon interaction (EPI), at 300 K, the ‘pure electronic' contributions and the contributions from EPI to R1 line, R2 line, and U band of GGG:Cr3+ as well as their PS have been calculated, respectively. The total calculated results are in good agreement with all the experimental data. Their physical origins have been explained. It is found that the mixing-degree of |t2/2(3T1)e4T2> and |t232E> base-wavefunctions in the wavefunctions of R1 level of GGG:Cr3+ is considerable under normal pressure, and the mixing-degree rapidly decreases with increasing pressure. The change of the mixing-degree with pressure plays a key role for PS of R1 line or R2 line. At 300 K, both the temperature-independent contribution to R1 line (or R2 line or U band) from EPI and the temperature-dependent one are important. The remarkable difference between pressure-dependent behaviors of PS of R1 lines of GGG:Cr3+ and GSGG:Cr3+ results from the differences of their microscopic properties. The features of emission spectra of GGG:Cr3+ at various pressures have satisfactorily been explained.

  3. Quantum Monte Carlo, time-dependent density functional theory, and density functional theory calculations of diamondoid excitation energies and Stokes shifts

    CERN Document Server

    Marsusi, F; Drummond, N D

    2011-01-01

    We have computed the absorption and emission energies and hence Stokes shifts of small diamondoids as a function of size using different theoretical approaches, including density functional theory and quantum Monte Carlo (QMC) calculations. The absorption spectra of these molecules were also investigated by time-dependent density functional theory (TD-DFT) and compared with experiment. We have analyzed the structural distortion and formation of a self-trapped exciton in the excited state, and we have studied the effects of these on the Stokes shift as a function of size. Compared to recent experiments, QMC overestimates the excitation energies by about 0.8(1) eV on average. Benefiting from a cancellation of errors, the optical gaps obtained in DFT calculations with the B3LYP functional are in better agreement with experiment. It is also shown that TD-B3LYP calculations can reproduce most of the features found in the experimental spectra. According to our calculations, the structures of diamondoids in the exci...

  4. Switching from static to adaptable and dynamic building envelopes: A paradigm shift for the energy efficiency in buildings

    Directory of Open Access Journals (Sweden)

    Marco Perino

    2015-11-01

    Full Text Available The key role of the building envelope in attaining building energy efficiency and satisfactory indoor comfort has long been established. Nevertheless, until recent times, all efforts and attention have mainly been focused on increasing and optimizing the thermal insulation of the envelope components. This strategy was a winning approach for a long time, but its limitations became obvious when users and designers started to consider the overall energy demand of a building and started to aim for Zero Energy Building (ZEB or nearly ZEB goals. New and more revolutionary concepts and technologies needed to be developed to satisfy such challenging requirements. The potential benefits of this technological development are relevant since the building envelope plays a key role in controlling the energy and mass flows from outdoors to indoors (and vice versa and, moreover, the facades offer a significant opportunity for solar energy exploitation. Several researches have demonstrated that the limitation of the existing facades could be overcome only by switching from ‘static’ to ‘responsive’ and ‘dynamic’ systems, such as Multifunctional Facade Modules (MFMs and Responsive Building Elements (RBE. These components are able to continuously and pro-actively react to outdoor and indoor environment conditions and facilitate and enhance the exploitation of renewable and low exergy sources. In order to reduce the energy demand, to maximize the indoor comfort conditions and to produce energy at the site, these almost ‘self-sufficient’, or even ‘positive energy’ building skins frequently incorporate different technologies and are functionally connected to other building services and installations. An overview of the technological evolution of the building envelope that has taken place, ranging from traditional components to the innovative skins, will be given in this paper, while focusing on the different approaches that have characterized this

  5. Estimation of individual binding energies in some dimers involving multiple hydrogen bonds using topological properties of electron charge density

    Energy Technology Data Exchange (ETDEWEB)

    Ebrahimi, A., E-mail: Ebrahimi@hamoon.usb.ac.ir [Department of Chemistry, University of Sistan and Baluchestan, P.O. Box 98135-674, Zahedan (Iran, Islamic Republic of); Habibi Khorassani, S.M.; Delarami, H. [Department of Chemistry, University of Sistan and Baluchestan, P.O. Box 98135-674, Zahedan (Iran, Islamic Republic of)

    2009-11-18

    Individual hydrogen bond (HB) energies have been estimated in several systems involving multiple HBs such as adenine-thymine and guanine-cytosine using electron charge densities calculated at X...H hydrogen bond critical points (HBCPs) by atoms in molecules (AIM) method at B3LYP/6-311++G** and MP2/6-311++G** levels. A symmetrical system with two identical H bonds has been selected to search for simple relations between {rho}{sub HBCP} and individual E{sub HB}. Correlation coefficient between E{sub HB} and {rho}{sub HBCP} in the base of linear, quadratic, and exponential equations are acceptable and equal to 0.95. The estimated individual binding energies E{sub HB} are in good agreement with the results of atom-replacement approach and natural bond orbital analysis (NBO). The E{sub HB} values estimated from {rho} values at H...X BCP are in satisfactory agreement with the main geometrical parameter H...X. With respect to the obtained individual binding energies, the strength of a HB depends on the substituent and the cooperative effects of other HBs.

  6. Application of object-oriented programming in a time-dependent density-functional theory calculation of exciton binding energies

    CERN Document Server

    Yang, Zeng-hui

    2013-01-01

    This paper discusses the benefits of object-oriented programming to scientific computing, using our recent calculations of exciton binding energies with time-dependent density-functional theory (arXiv: 1302.6972) as a case study. We find that an object-oriented approach greatly facilitates the development, the debugging, and the future extension of the code by promoting code reusing. We show that parallelism is added easily in our code in a object-oriented fashion with ScaLAPACK, Boost::MPI and OpenMP.

  7. Japan’s need for Russian oil and gas: A shift in energy flows to the Far East

    International Nuclear Information System (INIS)

    This article examines the choices of Japan’s governmental institutions vis-à-vis Russian supplies of oil and gas. First, there is a perceived need to diversify the sources of crude oil in order to avoid too much reliance on the Middle East. Following the inauguration of the Sakhalin oil projects and completion of the ESPO pipeline, Russian crude oil is nearing a 10% share in the Japanese market. It is suggested that Russian crude oil supplies have been chosen due to their proximity, safety and flexibility, and their positive effect on Japan’s bargaining power in relation to crude suppliers in the Middle East. Second, Japan’s shift from nuclear to LNG in power generation after the Fukushima accident in March 2011 increased LNG imports by 25% in just two years. While Qatar expanded its market share the most, Russia also gained, even though it only had one operational LNG project in Sakhalin-2. Russian companies are now working on several LNG projects in Northeast Asia and the Arctic region. However, the resumption of nuclear power in Japan might have a negative impact on new Russian LNG projects. - Highlights: • Russia’s oil export will gain a 10% share in Japan. • Russian companies are accelerating several LNG projects in NE Asia. • Japan’s exploration activity in East Siberia has reached the investment stage

  8. On the Inclusion of Energy-Shifting Demand Response in Production Cost Models: Methodology and a Case Study

    Energy Technology Data Exchange (ETDEWEB)

    O' Connell, Niamh [Technical Univ. of Denmark, Lyngby (Denmark); Hale, Elaine [National Renewable Energy Lab. (NREL), Golden, CO (United States); Doebber, Ian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jorgenson, Jennie [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-07-20

    In the context of future power system requirements for additional flexibility, demand response (DR) is an attractive potential resource. Its proponents widely laud its prospective benefits, which include enabling higher penetrations of variable renewable generation at lower cost than alternative storage technologies, and improving economic efficiency. In practice, DR from the commercial and residential sectors is largely an emerging, not a mature, resource, and its actual costs and benefits need to be studied to determine promising combinations of physical DR resource, enabling controls and communications, power system characteristics, regulatory environments, market structures, and business models. The work described in this report focuses on the enablement of such analysis from the production cost modeling perspective. In particular, we contribute a bottom-up methodology for modeling load-shifting DR in production cost models. The resulting model is sufficiently detailed to reflect the physical characteristics and constraints of the underlying flexible load, and includes the possibility of capturing diurnal and seasonal variations in the resource. Nonetheless, the model is of low complexity and thus suitable for inclusion in conventional unit commitment and market clearing algorithms. The ability to simulate DR as an operational resource on a power system over a year facilitates an assessment of its time-varying value to the power system.

  9. Animism, Creativity, and a Tree: Shifting into Nature Connection through Attention to Subtle Energies and Contemplative Art Practice

    Science.gov (United States)

    Flowers, Michelle; Lipsett, Lisa; Barrett, M. J.

    2014-01-01

    What can happen when the "monkey mind" of habitual conceptual thought is awakened to the more-than-human through attention to subtle energies and artmaking? Drawing on autoethnographic methods, we demonstrate how one graduate student's creative engagement with a tree brought animist theory to life. This paper illustrates how a…

  10. Theoretical and experimental study of the excitonic binding energy in GaAs/AlGaAs single and coupled double quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, E.M., E-mail: eldermantovani@yahoo.com.br [Departamento de Física, Química e Biologia, Universidade Estadual Paulista, C. P. 266, Presidente Prudente, São Paulo 17700-000 (Brazil); César, D.F. [Departamento de Física, Universidade Federal de São Carlos, C. P. 676, São Carlos, São Paulo (Brazil); Franchello, F.; Duarte, J.L.; Dias, I.F.L.; Laureto, E. [Departamento de Física, Universidade Estadual de Londrina, C. P. 6001, Londrina, Paraná (Brazil); Elias, D.C.; Pereira, M.V.M.; Guimarães, P.S.S. [Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, C. P. 702, Belo Horizonte, Minas Gerais (Brazil); Quivy, A.A. [Laboratório de Novos Materiais Semicondutores, Instituto de Física, Universidade de São Paulo, C. P. 66318, São Paulo (Brazil)

    2013-12-15

    This paper discusses the theoretical and experimental results obtained for the excitonic binding energy (E{sub b}) in a set of single and coupled double quantum wells (SQWs and CDQWs) of GaAs/AlGaAs with different Al concentrations (Al%) and inter-well barrier thicknesses. To obtain the theoretical E{sub b} the method proposed by Mathieu, Lefebvre and Christol (MLC) was used, which is based on the idea of fractional-dimension space, together with the approach proposed by Zhao et al., which extends the MLC method for application in CDQWs. Through magnetophotoluminescence (MPL) measurements performed at 4 K with magnetic fields ranging from 0 T to 12 T, the diamagnetic shift curves were plotted and adjusted using two expressions: one appropriate to fit the curve in the range of low intensity fields and another for the range of high intensity fields, providing the experimental E{sub b} values. The effects of increasing the Al% and the inter-well barrier thickness on E{sub b} are discussed. The E{sub b} reduction when going from the SQW to the CDQW with 5 Å inter-well barrier is clearly observed experimentally for 35% Al concentration and this trend can be noticed even for concentrations as low as 25% and 15%, although the E{sub b} variations in these latter cases are within the error bars. As the Zhao's approach is unable to describe this effect, the wave functions and the probability densities for electrons and holes were calculated, allowing us to explain this effect as being due to a decrease in the spatial superposition of the wave functions caused by the thin inter-well barrier. -- Highlights: • Magnetophotoluminescence results from coupled double quantum wells are reported. • Theoretical and experimental values for excitonic binding energy (E{sub b}) are obtained. • The effects of increasing the inter-well barrier height and thickness on E{sub b} are discussed. • An E{sub b} reduction is observed when going from zero to the 5 Å inter-well barrier

  11. Effect of high energy proton irradiation on InAs/GaAs quantum dots: Enhancement of photoluminescence efficiency (up to {approx}7 times) with minimum spectral signature shift

    Energy Technology Data Exchange (ETDEWEB)

    Sreekumar, R.; Mandal, A. [Centre for Nanoelectronics, Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, Maharashtra (India); Gupta, S.K. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India); Chakrabarti, S., E-mail: subho@ee.iitb.ac.in [Centre for Nanoelectronics, Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, Maharashtra (India)

    2011-11-15

    Graphical abstract: Authors demonstrate enhancement in photoluminescence efficiency (7 times) in single layer InAs/GaAs quantum dots using proton irradiation without any post-annealing treatment via either varying proton energy (a) or fluence (b). The increase in PL efficiency is explained by a proposed model before (c) and after irradiation (d). Highlights: {yields} Proton irradiation improved PL efficiency in InAs/GaAs quantum dots (QDs). {yields} Proton irradiation favoured defect and strain annihilation in InAs/GaAs QDs. {yields} Reduction in defects/non-radiative recombination improved PL efficiency. {yields} Protons could be used to improve PL efficiency without spectral shift. {yields} QD based devices will be benefited by this technique to improve device performance. -- Abstract: We demonstrate 7-fold increase of photoluminescence efficiency in GaAs/(InAs/GaAs) quantum dot hetero-structure, employing high energy proton irradiation, without any post-annealing treatment. Protons of energy 3-5 MeV with fluence in the range (1.2-7.04) x 10{sup 12} ions/cm{sup 2} were used for irradiation. X-ray diffraction analysis revealed crystalline quality of the GaAs cap layer improves on proton irradiation. Photoluminescence study conducted at low temperature and low laser excitation density proved the presence of non-radiative recombination centers in the system which gets eliminated on proton irradiation. Shift in photoluminescence emission towards higher wavelength upon irradiation substantiated the reduction in strain field existed between GaAs cap layer and InAs/GaAs quantum dots. The enhancement in PL efficiency is thus attributed to the annihilation of defects/non-radiative recombination centers present in GaAs cap layer as well as in InAs/GaAs quantum dots induced by proton irradiation.

  12. Methanol/sorbitol co-feeding induction enhanced porcine interferon-α production by P. pastoris associated with energy metabolism shift.

    Science.gov (United States)

    Gao, Min-Jie; Li, Zhen; Yu, Rui-Song; Wu, Jian-Rong; Zheng, Zhi-Yong; Shi, Zhong-Ping; Zhan, Xiao-Bei; Lin, Chi-Chung

    2012-09-01

    The production of porcine interferon-α (pIFN-α) by Pichia pastoris was largely enhanced when adopting sorbitol/methanol co-feeding induction strategy at 30 °C in a 10-L fermentor. Analysis of energy regeneration pattern and carbon metabolism revealed that major energy metabolism energizing pIFN-α synthesis shifted from formaldehyde dissimilatory energy metabolism pathway to TCA cycle under the methanol/sorbitol co-feeding induction strategy. The sorbitol/methanol co-feeding induction strategy weakened formaldehyde dissimilatory pathway and repressed the accumulation of toxic metabolite-formaldehyde, reduced theoretical oxygen consumption rate and oxygen supply requirement, and increased energy/methanol utilization efficiency so that more methanol could be effectively used for pIFN-α synthesis. As a result, pIFN-α antiviral activity reached a highest level of 1.8 × 10(7) IU/mL which was about 10- to 200-folds of those obtained under pure methanol induction at 20 and 30 °C, respectively.

  13. Measurement of the minimum binding energy of the 2p sigma molecular orbital formed in heavy ion collisions

    International Nuclear Information System (INIS)

    In order to study the minimum 2p sigma binding energy and its collision broadening, a copper ion beam was extracted from the Cs-sputter source and accelerated by the EN-tandem at Western Michigan University. Copper beams of ten different energies between 3 and 56 MeV were directed onto a pure thin (approx. 50μg) and a pure thick (approx. 5 mg) copper target. The x-rays emitted under 900 were reduced in intensity with an 11 mil thick pure aluminum absorber and observed with an 80mm2 Si(Li) detector. We were able to obtain quite intense 2p sigma MO-spectra with Cu-beams as slow as 3, 4, 5 and 7 MeV for thick as well as the thin targets

  14. Modeling the Catalysis of Anti-Cocaine Catalytic Antibody: Competing Reaction Pathways and Free Energy Barriers

    OpenAIRE

    Pan, Yongmei; Gao, Daquan; Zhan, Chang-Guo

    2008-01-01

    The competing reaction pathways and the corresponding free energy barriers for cocaine hydrolysis catalyzed by an anti-cocaine catalytic antibody, mAb 15A10, were studied by using a novel computational strategy based on the binding free energy calculations on the antibody binding with cocaine and transition states. The calculated binding free energies were used to evaluate the free energy barrier shift from the cocaine hydrolysis in water to the antibody-catalyzed cocaine hydrolysis for each ...

  15. Ba 4d core-level spectroscopy in the YBa2Cu3O6.9 high-Tc superconductor: Existence of a surface-shifted component

    International Nuclear Information System (INIS)

    Two sets of spin-orbit split Ba 4d core-level photoemission peaks were observed in a crystal of YBa2Cu3O6.9. From constant final-state measurements taken as a function of kinetic energy, the low-binding-energy doublet is identified as a surface component. Possible origins of the surface shift are discussed

  16. Free energy calculations on Transthyretin dissociation and ligand binding from Molecular Dynamics Simulations

    DEFF Research Database (Denmark)

    Sørensen, Jesper; Hamelberg, Donald; McCammon, J. Andrew

    experimental results have helped to explain this aberrant behavior of TTR, however, structural insights of the amyloidgenic process are still lacking. Therefore, we have used all-atom molecular dynamics simulation and free energy calculations to study the initial phase of this process. We have calculated...... the free energy changes of the initial tetramer dissociation under different conditions and in the presence of thyroxine....

  17. Bonding and chemical shifts in aluminosilicate glasses: importance of Madelung effects

    CERN Document Server

    Cruguel, H; Kerjan, O; Bart, F; Gautier-Soyer, M

    2003-01-01

    A detailed study of the XPS binding energy shifts of Si 2p, O 1s and Zr 3d in a series of aluminosilicate glasses (a three oxide glass: SiO sub 2 -Al sub 2 O sub 3 -CaO, three four-oxide glasses: SiO sub 2 -Al sub 2 O sub 3 -CaO-TiO sub 2 , ZrO sub 2 or CeO sub 2 , along with a six-oxide glass SiO sub 2 -Al sub 2 O sub 3 -CaO-TiO sub 2 -ZrO sub 2 -CeO sub 2) is presented. Their composition is such that these glasses have the same mean electronegativity, so that no changes in the atomic charges is expected. The binding energy shifts are interpreted in terms of initial and final state effects, and the balance of charge transfer contribution and electrostatic effects is discussed. Referred to the ternary glass, the binding energy shifts of the Si 2p, O 1s and Zr 3d lines in the complex glasses are due to an initial state effect, as the extraatomic relaxation is similar along the glass series. These shifts originate from electrostatic Madelung effects, likely coming from a structural change induced by the presenc...

  18. Binding energy of adsorbates on a noble-metal surface: exchange and correlation effects.

    Science.gov (United States)

    Rohlfing, Michael; Bredow, Thomas

    2008-12-31

    We discuss the adsorption of xenon and of PTCDA on the silver (111) surface within a first-principles approach, focusing on the adsorbate-substrate interaction energy as a function of distance. We combine exact exchange with correlation energy from the adiabatic-connection fluctuation-dissipation theorem. At a large distance Z from the surface, the correlation causes a van der Waals attraction [approximately -C3/(Z - Z0)3]. At a closer distance, the attraction deviates from its asymptotic form and, combined with the repulsive exact-exchange energy, yields an equilibrium in close agreement with experiment. PMID:19437654

  19. Stacked search for time shifted high energy neutrinos from gamma ray bursts with the \\ANTARES neutrino telescope

    CERN Document Server

    Adrian-Martínez, S; André, M; Anton, G; Ardid, M; Aubert, J -J; Baret, B; Barrios-Marti, J; Basa, S; Bertin, V; Biagi, S; Bormuth, R; Bouwhuis, M C; Bruijn, R; Brunner, J; Busto, J; Capone, A; Caramete, L; Carr, J; Chiarusi, T; Circella, M; Coniglione, R; Costantini, H; Coyle, P; Creusot, A; Dekeyser, I; Deschamps, A; De Bonis, G; Distefano, C; Donzaud, C; Dornic, D; Drouhin, D; Dumas, A; Eberl, T; Elsasser, D; Enzenhofer, A; Fehn, K; Felis, I; Fermani, P; Folger, F; Fusco, L A; Galatà, S; Gay, P; Geisselsoeder, S; Geyer, K; Giordano, V; Gleixner, A; Gracia-Ruiz, R; Graf, K; Hallmann, S; van Haren, H; Heijboer, A J; Hello, Y; Hernàndez-Rey, J J; Hoessl, J; Hofestadt, J; Hugon, C; James, C W; de Jong, M; Kadler, M; Kadler, M; Kalekin, O; Katz, U; Kiessling, D; Kooijman, P; Kouchner, A; Kreter, M; Kreykenbohm, I; Kulikovskiy, V; Lahmann, R; Lefèvre, D; Leonora, E; Marcelin, M; Margiotta, A; Marinelli, A; Martínez-Mora, J A; Mathieu, A; Michael, T; Migliozzi, P; Moussa, A; Muller, C; Nezri, E; Pavalas, G E; Pellegrino, C; Perrina, C; Piattelli, P; Popa, V; Pradier, T; Racca, C; Riccobene, G; Richter, R; Roensch, K; Saldaña, M; Samtleben, D F E; Sánchez-Losa, A; Sanguineti, M; Sapienza, P; Schmid, J; Schnabel, J; Schussler, F; Seitz, T; Sieger, C; Spurio, M; Steijger, J J M; Stolarczyk, Th; Taiuti, M; Tamburini, C; Trovato, A; Tselengidou, M; Tonnis, C; Vallage, B; Vallée, C; Van Elewyck, V; Visser, E; Vivolo, D; Wagner, S; Wilms, J; Zornoza, J D; Zúñiga, J

    2016-01-01

    A search for high-energy neutrino emission correlated with gamma-ray bursts outside the electromagnetic prompt-emission time window is presented. Using a stacking approach of the time delays between reported gamma-ray burst alerts and spatially coincident muon-neutrino signatures, data from the Antares neutrino telescope recorded between 2007 and 2012 are analysed. One year of public data from the IceCube detector between 2008 and 2009 have been also investigated. The respective timing pro?les are scanned for statistically significant accumulations within 40 days of the Gamma Ray Burst, as expected from Lorentz Invariance Violation effects and some astrophysical models. No significant excess over the expected accidental coincidence rate could be found in either of the two data sets. The average strength of the neutrino signal is found to be fainter than one detectable neutrino signal per hundred gamma-ray bursts in the Antares data at 90% confidence level.

  20. Predicting the binding free energy of the inclusion process of 2-hydroxypropyl-β-cyclodextrin and small molecules by means of the MM/3D-RISM method.

    Science.gov (United States)

    Sugita, Masatake; Hirata, Fumio

    2016-09-28

    A protocol to calculate the binding free energy of a host-guest system is proposed based on the MM/3D-RISM method, taking cyclodextrin derivatives and their ligands as model systems. The protocol involves the procedure to identify the most probable binding mode (MPBM) of receptors and ligands by means of the umbrella sampling method. The binding free energies calculated by the MM/3D-RISM method for the complexes of the seven ligands with the MPBM of the cyclodextrin, and with the fluctuated structures around it, are in agreement with the corresponding experimental data in a semi-quantitative manner. It suggests that the protocol proposed here is promising for predicting the binding affinity of a small ligand to a relatively rigid receptor such as cyclodextrin. PMID:27452185

  1. Predicting the binding free energy of the inclusion process of 2-hydroxypropyl-β-cyclodextrin and small molecules by means of the MM/3D-RISM method

    Science.gov (United States)

    Sugita, Masatake; Hirata, Fumio

    2016-09-01

    A protocol to calculate the binding free energy of a host–guest system is proposed based on the MM/3D-RISM method, taking cyclodextrin derivatives and their ligands as model systems. The protocol involves the procedure to identify the most probable binding mode (MPBM) of receptors and ligands by means of the umbrella sampling method. The binding free energies calculated by the MM/3D-RISM method for the complexes of the seven ligands with the MPBM of the cyclodextrin, and with the fluctuated structures around it, are in agreement with the corresponding experimental data in a semi-quantitative manner. It suggests that the protocol proposed here is promising for predicting the binding affinity of a small ligand to a relatively rigid receptor such as cyclodextrin.

  2. Binding energy and momentum distribution of nuclear matter using Green's function methods

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, A. (TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (CA)); Dickhoff, W.H. (Department of Physics, Washington University, St. Louis, Missouri 63130 (USA)); Polls, A. (Departament d' Estructura i Constituents de la Materia, Universitat de Barcelona, E-08028 Barcelona, Spain (ES))

    1991-05-01

    The influence of hole-hole (h-h) propagation in addition to the conventional particle-particle (p-p) propagation, on the energy per particle and the momentum distribution is investigated for the {ital v}{sub 2} central interaction which is derived from Reid's soft-core potential. The results are compared to Brueckner-Hartree-Fock calculations with a continuous choice for the single-particle (SP) spectrum. Calculation of the energy from a self-consistently determined SP spectrum leads to a lower saturation density. This result is not corroborated by calculating the energy from the hole spectral function, which is, however, not self-consistent. A generalization of previous calculations of the momentum distribution, based on a Goldstone diagram expansion, is introduced that allows the inclusion of h-h contributions to all orders. From this result an alternative calculation of the kinetic energy is obtained. In addition, a direct calculation of the potential energy is presented which is obtained from a solution of the ladder equation containing p-p and h-h propagation to all orders. These results can be considered as the contributions of selected Goldstone diagrams (including p-p and h-h terms on the same footing) to the kinetic and potential energy in which the SP energy is given by the quasiparticle energy. The results for the summation of Goldstone diagrams leads to a different momentum distribution than the one obtained from integrating the hole spectral function which in general gives less depletion of the Fermi sea. Various arguments, based partly on the results that are obtained, are put forward that a self-consistent determination of the spectral functions including the p-p and h-h ladder contributions (using a realistic interaction) will shed light on the question of nuclear saturation at a nonrelativistic level that is consistent with the observed depletion of SP orbitals in finite nuclei.

  3. Binding Free Energies for Nicotine Analogs Inhibiting Cytochrome P450 2A6 by a Combined Use of Molecular Dynamics Simulations and QM/MM-PBSA Calculations

    OpenAIRE

    Lu, Haiting; Huang, Xiaoqin; AbdulHameed, Mohamed Diwan M.; Zhan, Chang-Guo

    2014-01-01

    Molecular dynamics (MD) simulations and hybrid quantum mechanical/molecular mechanical (QM/MM) calculations have been perforemd to explore the dynamic behaviors of cytochrome P450 2A6 (CYP2A6) binding with nicotine analogs (that are typical inhibitors) and to calculate their binding free energies in combination with Poisson-Boltzmann surface area (PBSA) calculations. The combined MD simulations and QM/MM-PBSA calculations reveal that the most important structural parameters affecting the CYP2...

  4. ADMET, Docking studies & binding energy calculations of some Novel ACE - inhibitors for the treatment of Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Gade Deepak Reddy

    2012-09-01

    Full Text Available Diabetic Nephropathy (DN is one of the major complications of diabetes mellitus, representing the leading of cause of chronic renal disease and a major cause of morbidity and mortality in both type 1 and type 2 diabetic patients. The Renin-Angiotensin-Aldosterone System (RAAS has been implicated in the pathophysiology of DN, and suggests a therapeutic target for blocking this system. Therefore, inhibition of RAAS plays a crucial role in the treatment of DN and therapeutic intervention mostly involves administration of angiotensin converting enzyme (ACE inhibitors and angiotensin AT1 receptor blockers. In this current study, we have used computational methods to design 37 novel ACE-inhibitors and evaluated them for the interaction with the enzyme ACE through insilico analysis. The obtained results were compared with the standard drug enalapril to find out the potential inhibitors. Here we report that ligand 4 exhibited strongest inhibitory activity among all. All the analogs are also screened for their ADME & Toxicity profiles using insilico tools and ligand 9 is having better binding affinity next to ligand 4, and also having better ADMET profile when compared to that of ligand 4. Post docking calculations were also performed for the docked complexes in order to identify the individual ligand binding energies by employing Multi-Ligand Bimolecular Association with Energetics (Embrace

  5. Halide Binding and Inhibition of Laccase Copper Clusters: The Role of Reorganization Energy

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta

    2015-01-01

    complicate characterization. Understanding these processes at the molecular level is thus desirable but theoretically unexplored. This paper reports systematic calculations of geometries, reorganization energies, and ionization energies for all partly oxidized states of the trinuclear copper clusters...... in realistic models with similar to 200 atoms. Corrections for scalar-relativistic effects, dispersion, and thermal effects were estimated. Fluoride, chloride, hydroxide, or water was bound to the T2 copper site of the oxidized resting state, and the peroxo intermediate was also computed for reference...

  6. Optical determination of phosphorus acceptor binding energy in bulk wide-gap II-VI semimagnetic semiconductors

    International Nuclear Information System (INIS)

    Zn1-xMnxTe and Cd1-xMnxTe semimagnetic semiconductors doped with phosphorus have been investigated by means of the resistivity, Hall effect, photoluminescence and reflectance measurements. The high p-type doping level of these materials was achieved using Zn3P2 and CdP2 as the sources of P-impurities. By applying a unique technology of high-pressure annealing we were able to overcome a self-compensation in Zn1-xMnxTe:P. As a result, the sample with high and controllable concentration of electrical active acceptors were produced. The ground state binding energy of phosphorus acceptors in both Zn1-xMnxTe and Cd1-xMnxTe as well as its variation with the phosphorus doping level were optically determined. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Orbital momentum distribution and binding energies for the complete valence shell of molecular chlorine by electron momentum spectroscopy

    International Nuclear Information System (INIS)

    The complete valence shell binding energy spectrum (10-50 eV) of Cl2 has been determined using electron momentum (binary (e,2e)) spectroscopy. The inner valence region, corresponding to 4σu and 4σg ionization, has been measured for the first time and shows extensive splitting of the ionization strength due to electron correlation effects. These measurements are compared with the results of many-body calculations using Green's function and CI methods employing unpolarised as well as polarised wave functions. Momentum distributions, measured in both the outer and inner valence regions, are compared with calculations using a range of unpolarised and polarised wave functions. Computed orbital density maps in momentum and position space for oriented Cl2 molecules are discussed in comparison with the measured and calculated spherically averaged momentum distributions

  8. THE GENERALIZED RIEMANN PROBLEM FOR A SCALAR NONCONVEX COMBUSTION MODEL-THE PERTURBATION ON INITIAL BINDING ENERGY

    Institute of Scientific and Technical Information of China (English)

    Pan Lijun; Sheng Wancheng

    2012-01-01

    In this article,we study the generalized Riemann problem for a scalar nonconvex Chapman-Jouguet combustion model in a neighborhood of the origin (t > 0) on the (x,t) plane.We focus our attention to the perturbation on initial binding energy.The solutions are obtained constructively under the entropy conditions.It can be found that the solutions are essentially different from the corresponding Piemann solutions for some cases.Especially,two important phenomena are observed:the transition from detonation to deflagration followed by a shock,which appears in the numerical simulations [7,27]; the transition from deflagration to detonation (DDT),which is one of the core problems in gas dynamic combustion.

  9. Simulation investigations in the binding energy and mechanical properties of HMX-based polymer-bonded explosives

    Institute of Scientific and Technical Information of China (English)

    XIAO Jijun; FANG Guoyong; JI Guangfu; XIAO Heming

    2005-01-01

    The molecular simulations of the well-known high explosive β-HMX (cyclotetramethylene tetranitramine) and its fluorine containing polymer-bonded explosives (PBXs) were carried out with the combination method of quantum mechanics, molecular mechanics and molecular dynamics. The atomic cluster model, containing the β-HMX molecule and the polymer molecule whose chain dimension was about the same as β-HMX's, was fully optimized by AM1 and PM3 semi-empirical molecular orbital and molecular mechanical methods using COMPASS and PCFF force field. Then the calculated binding energy is found to be linearly correlated to each other. Molecular dynamics simulations using COMPASS force field were performed for β-HMX crystal and the PBXs involving β-HMX and a series of fluorine containing polymers. Their elastic coefficients, moduli and Poisson's ratios were calculated. It is found that the mechanical properties of β-HMX can be effectively improved by blending with fluorine containing polymers in small amounts.

  10. MMPBSA decomposition of the binding energy throughout a molecular dynamics simulation of amyloid-beta (Abeta(10-35)) aggregation.

    Science.gov (United States)

    Campanera, Josep M; Pouplana, Ramon

    2010-04-15

    Recent experiments with amyloid-beta (Abeta) peptides indicate that the formation of toxic oligomers may be an important contribution to the onset of Alzheimer's disease. The toxicity of Abeta oligomers depend on their structure, which is governed by assembly dynamics. However, a detailed knowledge of the structure of at the atomic level has not been achieved yet due to limitations of current experimental techniques. In this study, replica exchange molecular dynamics simulations are used to identify the expected diversity of dimer conformations of Abeta(10-35) monomers. The most representative dimer conformation has been used to track the dimer formation process between both monomers. The process has been characterized by means of the evolution of the decomposition of the binding free energy, which provides an energetic profile of the interaction. Dimers undergo a process of reorganization driven basically by inter-chain hydrophobic and hydrophilic interactions and also solvation/desolvation processes.

  11. MMPBSA Decomposition of the Binding Energy throughout a Molecular Dynamics Simulation of Amyloid-Beta (Aß10−35 Aggregation

    Directory of Open Access Journals (Sweden)

    Josep M. Campanera

    2010-04-01

    Full Text Available Recent experiments with amyloid-beta (Aβ peptides indicate that the formation of toxic oligomers may be an important contribution to the onset of Alzheimer’s disease. The toxicity of Aβ oligomers depend on their structure, which is governed by assembly dynamics. However, a detailed knowledge of the structure of at the atomic level has not been achieved yet due to limitations of current experimental techniques. In this study, replica exchange molecular dynamics simulations are used to identify the expected diversity of dimer conformations of Aβ10−35 monomers. The most representative dimer conformation has been used to track the dimer formation process between both monomers. The process has been characterized by means of the evolution of the decomposition of the binding free energy, which provides an energetic profile of the interaction. Dimers undergo a process of reorganization driven basically by inter-chain hydrophobic and hydrophilic interactions and also solvation/desolvation processes.

  12. Size-dependent stability toward dissociation and ligand binding energies of phosphine-ligated gold cluster ions

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Grant E.; Priest, Thomas A.; Laskin, Julia

    2014-01-01

    The stability of sub-nanometer size gold clusters ligated with organic molecules is of paramount importance to the scalable synthesis of monodisperse size-selected metal clusters with highly tunable chemical and physical properties. For the first time, a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR-MS) equipped with surface induced dissociation (SID) has been employed to investigate the time and collision energy resolved fragmentation behavior of cationic doubly charged gold clusters containing 7-9 gold atoms and 6-7 triphenylphosphine (TPP) ligands prepared by reduction synthesis in solution. The TPP ligated gold clusters are demonstrated to fragment through three primary dissociation pathways: (1) Loss of a neutral TPP ligand from the precursor gold cluster, (2) asymmetric fission and (3) symmetric fission and charge separation of the gold core resulting in formation of complementary pairs of singly charged fragment ions. Threshold energies and activation entropies of these fragmentation pathways have been determined employing Rice-Ramsperger-Kassel-Marcus (RRKM) modeling of the experimental SID data. It is demonstrated that the doubly charged cluster ion containing eight gold atoms and six TPP ligands, (8,6)2+, exhibits exceptional stability compared to the other cationic gold clusters examined in this study due to its large ligand binding energy of 1.76 eV. Our findings demonstrate the dramatic effect of the size and extent of ligation on the gas-phase stability and preferred fragmentation pathways of small TPP-ligated gold clusters.

  13. Accurate computations of the structures and binding energies of the imidazole⋯benzene and pyrrole⋯benzene complexes

    Energy Technology Data Exchange (ETDEWEB)

    Ahnen, Sandra; Hehn, Anna-Sophia [Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, D-76131 Karlsruhe (Germany); Vogiatzis, Konstantinos D. [Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, D-76131 Karlsruhe (Germany); Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Straße 1a, D-76131 Karlsruhe (Germany); Trachsel, Maria A.; Leutwyler, Samuel [Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern (Switzerland); Klopper, Wim, E-mail: klopper@kit.edu [Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, D-76131 Karlsruhe (Germany); Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Straße 1a, D-76131 Karlsruhe (Germany)

    2014-09-30

    Highlights: • We have computed accurate binding energies of two NH⋯π hydrogen bonds. • We compare to results from dispersion-corrected density-functional theory. • A double-hybrid functional with explicit correlation has been proposed. • First results of explicitly-correlated ring-coupled-cluster theory are presented. • A double-hybrid functional with random-phase approximation is investigated. - Abstract: Using explicitly-correlated coupled-cluster theory with single and double excitations, the intermolecular distances and interaction energies of the T-shaped imidazole⋯benzene and pyrrole⋯benzene complexes have been computed in a large augmented correlation-consistent quadruple-zeta basis set, adding also corrections for connected triple excitations and remaining basis-set-superposition errors. The results of these computations are used to assess other methods such as Møller–Plesset perturbation theory (MP2), spin-component-scaled MP2 theory, dispersion-weighted MP2 theory, interference-corrected explicitly-correlated MP2 theory, dispersion-corrected double-hybrid density-functional theory (DFT), DFT-based symmetry-adapted perturbation theory, the random-phase approximation, explicitly-correlated ring-coupled-cluster-doubles theory, and double-hybrid DFT with a correlation energy computed in the random-phase approximation.

  14. A New Determination of the Binding Energy of Atomic Oxygen on Dust Grain Surfaces: Experimental Results and Simulations

    CERN Document Server

    He, Jiao; Hopkins, Tyler; Vidali, Gianfranco; Kaufman, Michael J

    2015-01-01

    The energy to desorb atomic oxygen from an interstellar dust grain surface, $E_{\\rm des}$, is an important controlling parameter in gas-grain models; its value impacts the temperature range over which oxygen resides on a dust grain. However, no prior measurement has been done of the desorption energy. We report the first direct measurement of $E_{\\rm des}$ for atomic oxygen from dust grain analogs. The values of $E_{\\rm des}$ are $1660\\pm 60$~K and $1850\\pm 90$~K for porous amorphous water ice and for a bare amorphous silicate film, respectively, or about twice the value previously adopted in simulations of the chemical evolution of a cloud. We use the new values to study oxygen chemistry as a function of depth in a molecular cloud. For $n=10^4$ cm$^{-3}$ and $G_0$=10$^2$ ($G_0$=1 is the average local interstellar radiation field), the main result of the adoption of the higher oxygen binding energy is that H$_2$O can form on grains at lower visual extinction $A_{\\rm V}$, closer to the cloud surface. A higher ...

  15. Exactly solvable tight-binding model on the RAN: fractal energy spectrum and Bose–Einstein condensation

    International Nuclear Information System (INIS)

    The Regularized Apollonian Network (RAN) is defined starting from a tetrahedral structure with four nodes all connected (generation 0). At any successive generations, new nodes are added and connected with the surrounding three nodes. As a result, a power-law cumulative distribution of connectivity P(k) ∝ 1/k η with η = ln(3)/ln(2) ≈ 1.585 is obtained. We initially consider a single-particle tight-binding model on the RAN. The eigenvalues of the Hamiltonian are exactly computed by a recursive approach for any size of the network. In the infinite size limit, the density of states and the cumulative distribution of states (integrated density of states) are also exactly determined. The relevant scaling behavior of the cumulative distribution close to the band bottom is shown to be a power law with an exponent depending on the spectral dimension and not on the dimension of the embedding space. We then consider a gas made by an infinite number of non-interacting bosons, each of them described by the tight-binding Hamiltonian on the RAN and we prove that, for sufficiently large bosonic density and sufficiently small temperature, a macroscopic fraction of the particles occupies the lowest single-particle energy state forming the Bose–Einstein condensate. Not only do we determine the transition temperature as a function of the bosonic density, but also the fraction of condensed particles, the fugacity, the energy and the specific heat for any temperature and bosonic density. (paper)

  16. On sulfur core level binding energies in thiol self-assembly and alternative adsorption sites: An experimental and theoretical study

    International Nuclear Information System (INIS)

    Characteristic core level binding energies (CLBEs) are regularly used to infer the modes of molecular adsorption: orientation, organization, and dissociation processes. Here, we focus on a largely debated situation regarding CLBEs in the case of chalcogen atom bearing molecules. For a thiol, this concerns the case when the CLBE of a thiolate sulfur at an adsorption site can be interpreted alternatively as due to atomic adsorption of a S atom, resulting from dissociation. Results of an investigation of the characteristics of thiol self-assembled monolayers (SAMs) obtained by vacuum evaporative adsorption are presented along with core level binding energy calculations. Thiol ended SAMs of 1,4-benzenedimethanethiol (BDMT) obtained by evaporation on Au display an unconventional CLBE structure at about 161.25 eV, which is close to a known CLBE of a S atom on Au. Adsorption and CLBE calculations for sulfur atoms and BDMT molecules are reported and allow delineating trends as a function of chemisorption on hollow, bridge, and atop sites and including the presence of adatoms. These calculations suggest that the 161.25 eV peak is due to an alternative adsorption site, which could be associated to an atop configuration. Therefore, this may be an alternative interpretation, different from the one involving the adsorption of atomic sulfur resulting from the dissociation process of the S–C bond. Calculated differences in S(2p) CLBEs for free BDMT molecules, SH group sulfur on top of the SAM, and disulfide are also reported to clarify possible errors in assignments

  17. On sulfur core level binding energies in thiol self-assembly and alternative adsorption sites: An experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Juanjuan [Institut des Sciences Moléculaires d’Orsay, Université-Paris Sud, 91405 Orsay (France); CNRS, UMR 8214, Institut des Sciences Moléculaires d’Orsay, Orsay ISMO, Bâtiment 351, Université Paris Sud, 91405 Orsay (France); Kara, Abdelkader, E-mail: abdelkader.kara@ucf.edu, E-mail: vladimir.esaulov@u-psud.fr [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Pasquali, Luca [Dipartimento di Ingegneria “E. Ferrari,” Università di Modena e Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); IOM-CNR, s.s. 14, Km. 163.5 in AREA Science Park, 34149 Basovizza, Trieste (Italy); Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park 2006 (South Africa); Bendounan, Azzedine; Sirotti, Fausto [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, F-91192 Gif-sur-Yvette Cedex (France); Esaulov, Vladimir A., E-mail: abdelkader.kara@ucf.edu, E-mail: vladimir.esaulov@u-psud.fr [Institut des Sciences Moléculaires d’Orsay, Université-Paris Sud, 91405 Orsay (France); CNRS, UMR 8214, Institut des Sciences Moléculaires d’Orsay, Orsay ISMO, Bâtiment 351, Université Paris Sud, 91405 Orsay (France); IOM-CNR, s.s. 14, Km. 163.5 in AREA Science Park, 34149 Basovizza, Trieste (Italy)

    2015-09-14

    Characteristic core level binding energies (CLBEs) are regularly used to infer the modes of molecular adsorption: orientation, organization, and dissociation processes. Here, we focus on a largely debated situation regarding CLBEs in the case of chalcogen atom bearing molecules. For a thiol, this concerns the case when the CLBE of a thiolate sulfur at an adsorption site can be interpreted alternatively as due to atomic adsorption of a S atom, resulting from dissociation. Results of an investigation of the characteristics of thiol self-assembled monolayers (SAMs) obtained by vacuum evaporative adsorption are presented along with core level binding energy calculations. Thiol ended SAMs of 1,4-benzenedimethanethiol (BDMT) obtained by evaporation on Au display an unconventional CLBE structure at about 161.25 eV, which is close to a known CLBE of a S atom on Au. Adsorption and CLBE calculations for sulfur atoms and BDMT molecules are reported and allow delineating trends as a function of chemisorption on hollow, bridge, and atop sites and including the presence of adatoms. These calculations suggest that the 161.25 eV peak is due to an alternative adsorption site, which could be associated to an atop configuration. Therefore, this may be an alternative interpretation, different from the one involving the adsorption of atomic sulfur resulting from the dissociation process of the S–C bond. Calculated differences in S(2p) CLBEs for free BDMT molecules, SH group sulfur on top of the SAM, and disulfide are also reported to clarify possible errors in assignments.

  18. Determination of a time-shift in the OPERA set-up using high energy horizontal muons in the LVD and OPERA detectors

    CERN Document Server

    Agafonova, N Yu; Ashikhmin, V V; Bari, G; Bressan, E; Evans, L; Garbini, M; Giusti, P; Malguin, A S; Persiani, R; Ryasny, V G; Ryazhskaya, O G; Sartorelli, G; Scapparone, E; Selvi, M; Shakirianova, I R; Votano, L; Wenninger, H; Yakushev, V F; Zichichi, A; Agafonova, N; Alexandrov, A; Bertolin, A; Brugnera, R; Buttner, B; Chiarella, V; Chukanov, A; D'Ambrosio, N; De Lellis, G; Di Crescenzo, A; Di Ferdinando, D; Di Marco, N; Dmitrievsky, S; Dracos, M; Dusini, S; Ebert, J; Ereditato, A; Ferber, T; Fini, R A; Garfagnini, A; Giacomelli, G; Göllnitz, C; Gornushkin, Y; Grianti, F; Gustavino, C; Hagner, C; Hierholzer, M; Hollnagel, A; Jakovcic, K; Jollet-Meregaglia, C; Klicek, B; Kose, U; Lenkeit, J; Ljubicic, A; Longhin, A; Malgin, A; Mandrioli, G; Matveev, V; Mauri, N; Medinaceli, E; Meregaglia, A; Muciaccia, M T; Naumov, D; Olshevsky, A; Paoloni, A; Pastore, A; Patrizii, L; Pozzato, M; Pupilli, F; Rosa, G; Rostovtseva, I; Russo, A; Ryazhskaya, O; Schembri, A; Shakirianova, I; Sheshukov, A; Simone, S; Sioli, M; Sirignano, C; Sirri, G; Spinetti, M; Stanco, L; Stipcevic, M; Tenti, M; Terranova, F; Tioukov, V; Votano, L; Wonsak, B; Yakushev, V; Zaitsev, Y; Zemskova, S

    2012-01-01

    The purpose of this work is to report the measurement of a time-shift in the OPERA set-up in a totally independent way from Time Of Flight (TOF) measurements of CNGS neutrino events. The LVD and OPERA experiments are both installed in the same laboratory: LNGS. The relative position of the two detectors, separated by an average distance of ~ 160 m, allows the use of very high energy horizontal muons to cross-calibrate the timing systems of the two detectors, using a TOF technique which is totally independent from TOF of CNGS neutrino events. Indeed, the OPERA-LVD direction lies along the so-called "Teramo anomaly", a region in the Gran Sasso massif where LVD has established, many years ago, the existence of an anomaly in the mountain structure, which exhibits a low m. w. e. thickness for horizontal directions. The "abundant" high-energy horizontal muons (nearly 100 per year) going through LVD and OPERA exist because of this anomaly in the mountain orography. The total live time of the data in coincidence corr...

  19. Study of lysozyme mobility and binding free energy during adsorption on a graphene surface

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, C. Masato [Flintridge Preparatory School, La Canada Flintridge, California 91011 (United States); Ma, Heng; Wei, Tao, E-mail: twei@lamar.edu [Dan F. Smith Department of Chemical Engineering, Lamar University, Beaumont, Texas 77710 (United States)

    2015-04-13

    Understanding protein adsorption is a key to the development of biosensors and anti-biofouling materials. Hydration essentially controls the adsorption process on hydrophobic surfaces, but its effect is complicated by various factors. Here, we present an ideal model system to isolate hydration effects—lysozyme adsorption on a flat hydrophobic graphene surface. Our all-atom molecular dynamics and molecular-mechanics/Poisson-Boltzmann surface area computation study reveal that lysozyme on graphene displays much larger diffusivity than in bulk water. Protein's hydration free energy within the first hydration shell is dominated by the protein-water electrostatic interactions and acts as an energy barrier for protein adsorption. On the other hand, the surface tension, especially that from the hydrophobic graphene, can effectively weaken the barrier to promote adsorption.

  20. Energy Landscape Topography Reveals the Underlying Link Between Binding Specificity and Activity of Enzymes

    Science.gov (United States)

    Chu, Wen-Ting; Wang, Jin

    2016-06-01

    Enzyme activity (often quantified by kcat/Km) is the main function of enzyme when it is active against the specific substrate. Higher or lower activities are highly desired for the design of novel enzyme and drug resistance. However, it is difficult to measure the activities of all possible variants and find the “hot-spot” within the limit of experimental time. In this study, we explore the underlying energy landscape of enzyme-substrate interactions and introduce the intrinsic specificity ratio (ISR), which reflects the landscape topography. By studying two concrete systems, we uncover the statistical correlation between the intrinsic specificity and the enzyme activity kcat/Km. This physics-based concept and method show that the energy landscape topography is valuable for understanding the relationship between enzyme specificity and activity. In addition, it can reveal the underlying mechanism of enzyme-substrate actions and has potential applications on enzyme design.